4-Dipropylsulfamoyl-benzoic acid anion US20240116873, Compound Probenecid 4-Dipropylsulfamoyl-benzoic acid(probenecid) BDBM50206509 PROBENECID CHEMBL897 4-Dipropylsulfamoyl-benzoic acid Benemid Probalan
- Mollica, A; Costante, R; Akdemir, A; Carradori, S; Stefanucci, A; Macedonio, G; Ceruso, M; Supuran, CT Exploring new Probenecid-based carbonic anhydrase inhibitors: Synthesis, biological evaluation and docking studies. Bioorg Med Chem 23: 5311-8 (2015)
- Carradori, S; Mollica, A; Ceruso, M; D'Ascenzio, M; De Monte, C; Chimenti, P; Sabia, R; Akdemir, A; Supuran, CT New amide derivatives of Probenecid as selective inhibitors of carbonic anhydrase IX and XII: biological evaluation and molecular modelling studies. Bioorg Med Chem 23: 2975-81 (2015)
- D'Ascenzio, M; Carradori, S; Secci, D; Vullo, D; Ceruso, M; Akdemir, A; Supuran, CT Selective inhibition of human carbonic anhydrases by novel amide derivatives of probenecid: synthesis, biological evaluation and molecular modelling studies. Bioorg Med Chem 22: 3982-8 (2014)
- Horikawa, M; Kato, Y; Tyson, CA; Sugiyama, Y The potential for an interaction between MRP2 (ABCC2) and various therapeutic agents: probenecid as a candidate inhibitor of the biliary excretion of irinotecan metabolites. Drug Metab Pharmacokinet 17: 23-33 (2002)
- Inhibitory Assay Experimental results: The compounds had no obvious inhibitory effect on the drug transporter OAT3, and when the compounds were used clinically in combination with other drugs, there was almost no possibility of drug-drug interactions caused by OAT3 (superior to positive drug probenecid). The compounds and the positive drug probenecid had a certain inhibitory effect on the drug transporters OAT1 and OAT4, and when the compounds were used clinically in combination with other drugs, there was the possibility of drug-drug interactions caused by OAT1 and OAT4, but the inhibitory effect of the compounds was weaker than that of the positive drug probenecid, so the clinical safety risk was lower.
- ChEMBL_1504346 (CHEMBL3592683) Agonist activity at FPR2 in human PMN assessed as stimulation of Ca2+ influx measured every 5 secs for 240 secs by FLIPR assay in absence of probenecid
- ChEMBL_1504347 (CHEMBL3592684) Agonist activity at FPR2 in human PMN assessed as stimulation of Ca2+ influx measured every 5 secs for 240 secs by FLIPR assay in presence of probenecid
- Calcium Flux Assay Calcium Flux Assay Using Fluorometric Imaging Plate Reader (FLIPR). Buffer containing dye (from the FLIPR® Calcium 3 Assay Kit from Molecular Devices, a division of MDS Analytical Technologies and MDS Inc.) was prepared by dissolving the contents of one bottle into 200 mL Hank's Balanced Salt Solution containing 20 mM HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) and 2.5 mM probenecid. Growth media was removed from the cell plates and 25 μL of Hank's Balanced Salt Solution (HBSS) containing 20 mM HEPES, 0.05% BSA and 2.5 mM probenecid was added to each well followed by 25 μL of diluted dye using a Multidrop dispenser. The plates were then incubated for 1 hour at 37° C.
- Biological Assay A fluorescent imaging plate reader (FILEX/FLIPR station; Molecular Devices) was used to monitor intracellular calcium levels using the calcium-chelating dye Rim-4 (Molecular Probes). The excitation and emission wavelengths used to monitor fluorescence were 470-495 nm and 515-575 nm, respectively. Cells expressing purinergic receptors P2X3 (human) or P2X2/3 (human) were plated at a density of 15,000 cells/well in collagen-coated 384-well plates approximately 20 hours before beginning the assay. On the day of the assay, 20 μl of loading buffer (Hank's balanced salt solution, 20 mM HEPES, 0.5 mM CaCl2, 0.5 mM MgCl2, 0.1% BSA, 5 mM probenecid, 10 mM D-glucose monohydrate, 2 μM Fluo-4, and 5 units/mL, hexokinase, pH=7.4) was added and cells dye-loaded for 90 min at 37° C. The dye supernatant was removed and replaced with 45 μl probenecid buffer (Hank's balanced salt solution, 20 mM HEPES, 0.5 mM CaCl2, 0.5 mM MgCl2, 0.1% BSA, 5 mM probenecid, 10 mM D-glucose monohydrate, pH=7.4). The test compound was added in a volume of 5 μl and allowed to incubate for 30 min at 37° C.
- Fluorescence-Based Assay Chinese hamster ovary (CHO) cells overexpressing the human S1P2 gene were cultured in a Ham's F12 medium containing 10% fetal bovine serum (FBS), an antibiotic/antifungal agent and G418. CHO cells overexpressing the rat S1P2 gene were cultured in a Ham's F12 medium containing 10% FBS, penicillin/streptomycin and blasticidin S. The cultured cells were incubated in a Fura2-AM solution (5 uM) [a Ham's F12 medium containing FBS (10%), HEPES buffer (20 mM, pH 7.2 to 7.5) and probenecid (2.5 mM)] at 37 C. for 60 minutes. The cells were washed twice with a Hanks' balanced saline containing HEPES buffer (20 mM, pH 7.2 to 7.5) and probenecid (2.5 mM) and immersed in the same solution. A plate was mounted on a fluorescence-based drug screening system and the intracellular calcium ion concentration was measured for 30 seconds without stimulation.
- Inhibition Assay URAT1 (Uric Acid Transporter 1) is expressed on the apical membrane in renal tubules. It mediates the re-uptake of uric acid from the urine into the blood. Inhibition of URAT1 leads to increased excretion of uric acid in the urine, and is therefore a potential mode of action for drugs that lower serum uric acid concentrations. Probenecid and Benzbromarone, for example, have been used clinically for treatment of gout and hyperuricemia, and they both act on URAT1 to reduce uric acid reuptake. However, benzbromarone was withdrawn from the market due to liver toxicity via mechanisms independent of URAT1, and probenecid acts on numerous transporter proteins, resulting in interactions with a variety of other drugs.An in vitro URAT1 assay is useful for identifying compounds with potential activity in lowering serum uric acid. A suitable assay involves transfection of cells (e g human embryonic kidney cells "HEK") with a vector encoding human URAT1.
- Calcein Quenching Fluostar Assay A calcein quenching fluostar assay was performed in order to investigate the biological activity of the newly synthesized examples 1 to 57. This type of assay is disclosed in J. Biol. Chem., 2011, 286, 44319-44325 and Am. J. Physiol. Renal Physiol. (2010), 298, F224-230.The buffers used in the assay were prepared with the following compounds and quantities.500 ml of 4× buffer:3.2 mM MgSO4.7H2O (0.395 g)20 mM KCl (0.746 g)7.2 mM CaCl.2H2O (0.530 g)100 mM NaHepes (13.02 g)pH 7.4 w. HClTetracyclin Stock: Wash buffer (μl) Sucrose buffer (μl) 4x buffer 80000 35000 NaCl (1M) 34080 14910 H2O 199520 18970 Probenecid 6400 2800 Sucrose (1M) 0 68320 Total 320000 140000The total probenecid required to prepare the wash buffer and sucrose buffer is 6400+2800=9200 μl. An additional 500 μl of probenecid (5 plates at 100 μl each) is also required. Therefore, the total probenecid required is 9200 μl+500 μl=9700 μl. Sufficient probenecid is prepared using:690 mg probenecid;4850 μl NaOH 1M;1213 μl 4× buffer; and3638 μl H2O.Assay Experimental Protocol:1) Two days prior to commencement of the assay, seed 10,000 cells/well of 96 well black clear bottom plate (Greiner Poly-lysin plate). A 1:1 mix of Dulbecco's Modified Eagle's Medium: Nutrient Mixture F-12 (DMEM: F12) was obtained from Gibco. Tetracycline stock of 5 mg/ml in 96% ethanol is used. Medium: DMEM/F12/10% Donor Bovine Serum, Human AQP9 cell line+1:270,000 tetracyclin, mouse AQP9 cell line+1:2,700,000 tetracycline.2) Day of assay: Flick/slam off the medium and add 50 μl/well of loading solution: 5 ml DMEM/F12/10% Donor Bovine Serum, 25 μl Calcein AM from freshly dissolved aliquot in 50 μl DMSO (VWR #734-1434), and 100 μl Probenecid.3) Incubate the well for 90 minutes at 37° C.4) Perform one wash with 75 μl wash buffer.5) Add 75 μl of an example compound prepared in wash buffer per well.Example compounds are prepared in 500 μl U bottom PP plates (NUNC). 2.7 μl Substance in DMSO are added to row A; 180 μl of wash buffer+1% DMSO are added to rows B H. 90 μl from row A are transferred and mixed with all other wells (up to row G) to make a 3-fold dilution series.6) Assay in FLUOstar Optima at 25° C. Settings buffer addition at 135 μl/seconds, add 75 μl/well, record time course for 30 seconds, add sucrose buffer 3.6 seconds into recording.7) Normalization to initial in Excel.8) Fit to exponential decay function in GraphPad Prism 5.0, then arrange half live shrinking values according to wells and fit dose-response curves.
- FLIPR Assay The bioactivity of compounds is tested in a fluorometric imaging plate reader (FLIPR: Molecular Devices) using engineered CHO-K1 cells expressing the human CXCR3A coupled to a G protein (Galpha(16)). Cells are plated the day prior to bioassay in F12 medium supplemented with 10% FBS and G418 and hygromycin antibiotics to maintain recombinant selection. At the day of bioassay, cells are washed and dye loaded for one hour with Fluo-4-AM (Invitrogen) in Hanks Balanced Salt Solution (Invitrogen), buffered with 20 mM Hepes at pH 7.4 and sodium bicarbonate (0.015%), containing 5 mM probenecid. This buffer, but lacking the dye and containing probenecid at a concentration of 2.5 nM, is also is used for washing steps (wash buffer); or lacking both dye and probenecid but supplemented with 0.1% BSA for compound dilution steps (dilution buffer). Cells are washed free of excess dye and 60 microliter of wash buffer is added. Stock solutions of test compounds are made up at a concentration of 10 mM in DMSO, and serially diluted in dilution buffer to concentrations required for inhibition dose response curves. After a 10 minute incubation period at 37° C., 10 microliters of each compound dilution are transferred from a compound plate to the plate containing the recombinant cells in the FLIPR instrument according to the manufacturer's instructions. Following basal readings, 10 microliter CXCL10 agonist at a concentration of 20 nM (from Peprotech) is added, again using the FLIPR instrument. Changes in fluorescence are monitored before and after addition of the test compounds.
- FLIPR Assay The bioactivity of compounds is tested in a fluorometric imaging plate reader (FLIPR: Molecular Devices) using engineered CHO-K1 cells expressing the human CXCR3A (GenBank: AY242128) coupled to a G protein (Galpha(16)). Cells are plated the day prior to bioassay in F12 medium supplemented with 10% FBS and G418 and hygromycin antibiotics to maintain recombinant selection. At the day of bioassay, cells are washed and dye loaded for one hour with Fluo-4-AM (Invitrogen) in Hanks Balanced Salt Solution (Invitrogen), buffered with 20 mM Hepes at pH 7.4 and sodium bicarbonate (0.038%), containing 5 mM probenecid. This buffer, but lacking the dye and containing probenecid at a concentration of 2.5 mM, is also used for washing steps (wash buffer); or lacking both dye and probenecid but supplemented with 0.1% BSA for compound dilution steps (dilution buffer). Cells are washed free of excess dye and 60 microliter of wash buffer is added. Stock solutions of test compounds are made up at a concentration of 10 mM in DMSO, and serially diluted in dilution buffer to concentrations required for inhibition dose response curves. After a 10 minute incubation period at 37° C., 10 microliters of each compound dilution are transferred from a compound plate to the plate containing the recombinant cells in the FLIPR instrument according to the manufacturer's instructions. Following basal readings, 10 microliter CXCL10 agonist at a concentration of 20 nM (from Peprotech) is added, again using the FLIPR instrument. Changes in fluorescence are monitored before and after addition of the test compounds. Emission peak values above base level after CXCL10 addition are exported after base line subtraction.
- Inhibition Assay The cells expressing mouse EP1 receptor were seeded at 104 cells/well in 96-well plates and cultured for 2 days with 10% Fetal Bovine Serum (FBS)/alpha Modified Eagle Medium (alphaMEM) in the incubator (37° C., 5% CO2). The cells were washed with phosphate buffer, and load buffer (10% FBS/ ±MEM containing Fura2/AM (5 uM), indomethacin (20 uM) and probenecid (2.5 mM)) was then added to each well and cells were left standing for 1 hour. Load buffer of each well was discarded and assay buffer (Hank's Balanced Salt Solution (HBSS) containing indomethacin (2.5 mM), probenecid (2.5 mM), HEPES-NaOH (10 mM) and 0.1% (w/v) Bovine Serum Albumin (BSA)) was added to each well and plates were left at room temperature in a dark room for 1 hour. Afterwards, compounds of the present invention (10 uL) or PGE2 (10 uL) prepared with assay buffer was added to each well and intracellular calcium concentrations were measured using a Fluorescence Drug Screening System.
- FLIPR Assay The bioactivity of compounds is tested in a fluorometric imaging plate reader (FLIPR: Molecular Devices) using engineered CHO-K1 cells expressing the human CXCR3A (GenBank: AY242128) coupled to a G protein (Galpha(16)). Cells are plated the day prior to bioassay in F12 medium supplemented with 10% FBS and G418 and hygromycin antibiotics to maintain recombinant selection. At the day of bioassay, cells are washed and dye loaded for one hour with Fluo-4-AM (Invitrogen) in Hanks Balanced Salt Solution (Invitrogen), buffered with 20 mM Hepes at pH 7.4 and sodium bicarbonate (0.038%), containing 5 mM probenecid. This buffer, but lacking the dye and containing probenecid at a concentration of 2.5 mM, is also used for washing steps (wash buffer); or lacking both dye and probenecid but supplemented with 0.1% BSA for compound dilution steps (dilution buffer). Cells are washed free of excess dye and 60 microliter of wash buffer is added. Stock solutions of test compounds are made up at a concentration of 10 mM in DMSO, and serially diluted in dilution buffer to concentrations required for inhibition dose response curves. After a 10 minute incubation period at 37° C., 10 microliters of each compound dilution are transferred from a compound plate to the plate containing the recombinant cells in the FLIPR instrument according to the manufacturer's instructions. Following basal readings, 10 microliter CXCL10 agonist at a concentration of 20 nM (from Peprotech) is added, again using the FLIPR instrument. Changes in fluorescence are monitored before and after addition of the test compounds. Emission peak values above base level after CXCL10 addition are exported after base line subtraction.The calculated IC50 values may fluctuate depending on the daily assay performance. Fluctuations of this kind are known to those skilled in the art.
- GPR40 agonistic activity hGPR40-CHO stably transfected cells were seeded into a 96-well plate at a density of 3×104/well, and incubated overnight in a 37° C., 5% CO2 cell incubator; the medium was discarded, 100 μl of HBSS was added to each well, and 100 μl of Fluo-4 dye solution containing Probenecid was added and incubated at 37° C. for 90 min. After the incubation, the Fluo-4 dye solution was sucked out, 100 μl of HBSS buffer was added, and the dye was washed away; 100 μl of HBSS containing Probenecid was added to each well, and incubated at 37° C. for 10 min; different concentrations of drugs were added to each well of the 96-well plate and FLIPR (Molecular Devices) was used for readings according to the parameter setting table. The experimental results were analyzed. Agonistic activity=(compound well fluorescence value−blank control well fluorescence value)/(linoleic acid well fluorescence value−blank control well fluorescence value)×100%, finally compounds with better agonistic activity were selected to determine their EC50 at 100 nM.
- Binding Assay Fluorescent Imaging Plate Reader (FLIPR) assay: Briefly, 293-human or mouse P2X7 stable cells were incubated in sucrose buffer, pH 7.4 [KCl (5 mM), NaH2PO4.2H2O (9.6 mM), HEPES (25 mM), sucrose (280 mM), glucose (5 mM), CaCl2 (0.5 mM), and probenecid (0.1425 g in 3 mL 1N NaOH was added for 500 mL solution)] in 384-well plates.293-rat P2X7 stable cells were incubated in HHPB (pH 7.4) [consisting of Hank's BSS (1×); HEPES (pH 7.4) (20 mM) (Sigma); probenecid (0.710g/5 mL 1N NaOH) (Sigma); and BSA (0.05%) (Roche) which was added after the pH had been adjusted] in 384-well plates. Fluo-4 NW dye mix (Molecular Probes, Inc., Eugene, Oreg., USA) was prepared in buffer (see manufacturer's instructions). Cell plates were removed from the 37° C. incubator, the media discarded and then 30 μL of dye was added to each well. Plates were placed in the 37° C., non-CO2 incubator for 30 minutes and then room temperature for 30 minutes.
- In Vitro Assay Fluorescent Imaging Plate Reader (FLIPR) assay: Briefly, 293-human or mouse P2X7 stable cells were incubated in sucrose buffer, pH 7.4 [KCl (5 mM), NaH2PO4.2H2O (9.6 mM), HEPES (25 mM), sucrose (280 mM), glucose (5 mM), CaCl2 (0.5 mM), and probenecid (0.1425 g in 3 mL 1N NaOH was added for 500 mL solution)] in 384-well plates. 293-rat P2X7 stable cells were incubated in HHPB (pH 7.4) [consisting of Hank's BSS (1×); HEPES (pH 7.4) (20 mM) (Sigma); probenecid (0.710 g/5 mL 1N NaOH) (Sigma); and BSA (0.05%) (Roche) which was added after the pH had been adjusted] in 384-well plates. Fluo-4 NW dye mix (Molecular Probes, Inc., Eugene, Oreg., USA) was prepared in buffer (see manufacturer's instructions). Cell plates were removed from the 37° C. incubator, the media discarded and then 30 μL of dye was added to each well. Plates were placed in the 37° C., non-CO2 incubator for 30 minutes and then room temperature for 30 minutes.
- Inhibition Assay Stably expressing cell line (C6BU-1 cell transfected with human P2X3 receptor gene (GenBank accession number Y07683) was used. The cells were seeded in a 96-well microtiter plate at a concentration of 8000 cells/well and cultured in the medium (8.3% fetal bovine serum, 8.3% horse serum, 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 in M MgCl2, 5.0 mM CaCl2, 5.6 D-glucose, 2.5 mM probenecid, 1.0% BSA, and 0.08% Pluronic F-127, pH 7.5) and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH 7.5), and each well was added with 40 μL of this buffer. The plate was placed in High-Throughput Screening System FDSS 3000 (Hamamatsu Photonics K.K.). Measurement of fluorescence inte
- Inhibition Assay Stably expressing cell line (C6BU-1 cell transfected with human P2X3 receptor gene (GenBank accession number Y07683)) was used. The cells were seeded in a 96-well microtiter plate at a concentration of 8000 cells/well and cultured in the medium (8.3% fetal bovine serum, 8.3% horse serum, 1% antibiotic and antifungal in DMEM) for one day at 37 C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 uM Fluo-3-AM solution (pH 7.5) containing 20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 10% BSA, and 0.08% Pluronic F-127, and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH 7.5), and each well was added with 40 uL of this buffer. The plate was placed in High-Throughput Screening System FDSS 3000 (Hamamatsu Photonics K.K.).
- Intracellular Calcium Measurement to Assess Antagonist Activity A fluorescent imaging plate reader (FLEX/FLIPR station; Molecular Devices) was used to monitor intracellular calcium levels using the calcium-chelating dye Fluo-4 (Molecular Probes). The excitation and emission wavelengths used to monitor fluorescence were 470-495 nm and 515-575 nm, respectively. Cells expressing purinergic receptors P2X3 (human) or P2X2/3 (human) were plated at a density of 15,000 cells/well in collagen-coated 384-well plates approximately 20 hours before beginning the assay. On the day of the assay, 20 μl of loading buffer (Hank's balanced salt solution, 20 mM HEPES, 0.5 mM CaCl2, 0.5 mM MgCl2, 0.1% BSA, 5 mM probenecid, 10 mM D-glucose monohydrate, 2 μM Fluo-4, and 5 units/mL, hexokinase, pH=7.4) was added and cells dye-loaded for 90 min at 37° C. The dye supernatant was removed and replaced with 45 μl probenecid buffer (Hank's balanced salt solution, 20 mM HEPES, 0.5 mM CaCl2, 0.5 mM MgCl2, 0.1% BSA, 5 mM probenecid, 10 mM D-glucose monohydrate, pH=7.4). The test compound was added in a volume of 5 μl and allowed to incubate for 30 min at 37° C. The final assay DMSO concentration is 1%.The agonist, α,β-Me-ATP, was added in a volume of 20 μl at a concentration representing the EC80 value. The fluorescence was measured for an interval of 90 sec at 2 sec intervals and analyzed based on the increase in peak relative fluorescence units (RFU) compared to the basal fluorescence. Peak fluorescence was used to determine the response to agonist obtained at each concentration of test compound by the following equation: % Response=100*(RFU(test compound)−RFU(control))/(RFU(DMSO)−RFU(control)).
- Intracellular Calcium Measurement to Assess Antagonist Activity at Human P2X3 and Human P2X2/3 Receptors A fluorescent imaging plate reader (FLEX/FLIPR station; Molecular Devices) was used to monitor intracellular calcium levels using the calcium-chelating dye Fluo-4 (Molecular Probes). The excitation and emission wavelengths used to monitor fluorescence were 470-495 nm and 515-575 nm, respectively. Cells expressing purinergic receptors P2X3 (human) or P2X2/3 (human) were plated at a density of 15,000 cells/well in collagen-coated 384-well plates approximately 20 hours before beginning the assay. On the day of the assay, 20 μl of Loading buffer (Hank's balanced salt solution, 20 mM HEPES, 0.5 mM CaCl2, 0.5 mM MgCl2, 0.1% BSA, 5 mM probenecid, 10 mM D-glucose monohydrate, 2 μM Fluo-4, and 5 units/mL, hexokinase, pH=7.4) was added and cells dye-loaded for 90 min at 37° C. The dye supernatant was removed and replaced with 45 μl probenecid buffer (Hank's balanced salt solution, 20 mM HEPES, 0.5 mM CaCl2, 0.5 mM MgCl2, 0.1% BSA, 5 mM probenecid, 10 mM D-glucose monohydrate, pH=7.4). The test compound was added in a volume of 5 μl and allowed to incubate for 30 min at 37° C. The final assay DMSO concentration is 1%. The agonist, α,β-Me-ATP, was added in a volume of 20 μl at a concentration representing the EC80 value. The fluorescence was measured for an interval of 90 sec at 2 sec intervals and analyzed based on the increase in peak relative fluorescence units (RFU) compared to the basal fluorescence. Peak fluorescence was used to determine the response to agonist obtained at each concentration of test compound by the following equation: % Response=100*(RFU(test compound)−RFU(control)/RFU(DMSO)−RFU(control)).
- P2X3 Inhibition Assay Stably expressing cell line (C6BU-1 cell transfected with human P2X3 receptor gene (GenBank accession number Y07683)) was used. The cells were seeded in a 96-well microtiter plate at a concentration of 8000 cells/well and cultured in the medium (8.3% fetal bovine serum, 8.3% horse serum, 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (pH7.5) containing 20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 10% BSA, and 0.08% Pluronic F-127, and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH7.5), and each well was added with 40 μL of this buffer. The plate was placed in High-Throughput Screening System FDSS 3000 (Hamamatsu Photonics K.K.). Measurement of fluorescence intensity by FDSS 3000 was started, and 40 μL of DMSO solutions containing different concentrations of the test compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.1% Pluronic F-127, pH7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 40 nM ATP solution (50 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 3 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement.
- Cell-based Functional Assay Measurement of [Ca2+]i using a FLIPR: CHO-OX1 or CHO-OX2 cells are seeded into black-walled clear-base 384-well plates (Costar) at a density of 20,000 cells per well in F12-K medium supplemented with 10% FBS and selection antibiotic (500 ug/ml G418 or 15 ug/ml Blasticidin) and cultured overnight. The cells are incubated with equal volume of calcium4 loading buffer (Molecular Devices, Inc.) containing 2.5 mM probenecid at 37° C. for 30 min, followed by putative OX1 or OX2 receptor antagonists (dose-range 0.1 nM-10 μM) for another 30 min.
- Receptor Inhibition Assay Stably expressing cell line (C6BU-1 cell transfected with human P2X3 receptor gene (GenBank accession number Y07683) was used. The cells were seeded in a 384-well PDL-coated microtiter plate at a concentration of 3000 cells/well and cultured in the medium (8.3% fetal bovine serum, 8.3% horse serum, and 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.5% BSA, and 0.04% Pluronic P-127, pH 7.5) and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH 7.5), and each well was added with 20 μL of the washing buffer. The plate was placed in High-Throughput Screening System FLIPR 384 (Molecular Device Co.). Measurement of fluorescence intensity by FLIPR 884 was started, and 20 μL of DMSO solutions containing different concentrations of the test compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.1% Pluronic F-127, pH 7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 150 nM ATP solution (25 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 4 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement.
- Intracellular Calcium Measurement to Assess Antagonist Activity at Human P2X3 and Human P2X2/3 Receptors A fluorescent imaging plate reader (FLEX/FLIPR station; Molecular Devices) was used to monitor intracellular calcium levels using the calcium-chelating dye Fluo-4 (Molecular Probes). The excitation and emission wavelengths used to monitor fluorescence were 470-495 nm and 515-575 nm, respectively. Cells expressing purinergic receptors P2X3 (human) or P2X2/3 (human) were plated at a density of 15,000 cells/well in collagen-coated 384-well plates approximately 20 hours before beginning the assay. On the day of the assay, 20 μl of loading buffer (Hank's balanced salt solution, 20 mM HEPES, 0.5 mM CaCl2, 0.5 mM MgCl2, 0.1% BSA, 5 mM probenecid, 10 mM D-glucose monohydrate, 2 μM Fluo-4, and 5 units/mL, hexokinase, pH=7.4) was added and cells dye-loaded for 90 min at 37° C. The dye supernatant was removed and replaced with 45 μl probenecid buffer (Hank's balanced salt solution, 20 mM HEPES, 0.5 mM CaCl2, 0.5 mM MgCl2, 0.1% BSA, 5 mM probenecid, 10 mM D-glucose monohydrate, pH=7.4). The test compound was added in a volume of 5 μl and allowed to incubate for 30 min at 37° C. The final assay DMSO concentration is 1%. The agonist, α,β-Me-ATP, was added in a volume of 20 μl at a concentration representing the EC80 value. The fluorescence was measured for an interval of 90 sec at 2 sec intervals and analyzed based on the increase in peak relative fluorescence units (RFU) compared to the basal fluorescence. Peak fluorescence was used to determine the response to agonist obtained at each concentration of test compound by the following equation: % Response=100*(RFU(test compound)−RFU(control))/(RFU(DMSO)−RFU(control))The Examples were tested in triplicates per plate and mean values were plotted in Excel XLFit to determine IC50 values at the human P2X3 and human P2X2/3 receptors, percentage of maximal inhibition and the Hill coefficients.
- Receptor Inhibition Assay Rat P2X3 receptor gene (GenBank accession number NM_031075) was expressed in C6BU-1 cell. The C6BU-1 cells were seeded in a 96-well microtiter plate at a concentration of 2500 cells/well and cultured in the medium (7.0% fetal bovine serum, 7.0% horse serum, and 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. The plasmid was transfected into the cells using transfection reagent FuGENE6 (Promega). The transfected cells were cultured in the medium for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (pH 7.5) containing 20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 1% BSA, and 0.08% Pluronic F-127, and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH 7.5), and each well was added with 40 μL of this buffer. The plate was placed in High-Throughput Screening System FDSS 3000 (Hamamatsu Photonics K.K.). Measurement of fluorescence intensity by FDSS 3000 was started, and 40 μL of DMSO solutions containing different concentrations of the test compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM 137 NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.1% Pluronic F-127, pH 7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 50 nM ATP solution (50 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 4 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement.
- FLIPR Assay On the day before the measurement day, CHO cells expressing human GPR120 were plated at 10000 cells per well in a 384-well black plate (#3702, Corning) and incubated overnight in a CO2 incubator. On the day of the measurement, 4 μM Fluo-4 AM (fluorescence calcium indicator reagent) was incubated to be introduced into the human GPR120 expression CHO cells in the presence of 0.08% Pluronic F-127 in a CO2 incubator for 90 minutes. To the cells was added the test compound diluted with HBSS solution containing 20 mM HEPES and 2.5 mM probenecid. Variations in the intracellular calcium concentration were measured by Fluorescence Imaging Plate Reader (FLIPR; Molecular Devices) to examine the agonist action, and EC50 values were calculated.
- FLIPR Assay A calcium flux assay was used to determine the ability of the compounds to interfere with the binding between CCR9 and its chemokine ligand (TECK) in Chem1-hCCR9 overexpressing cells. hCCR9 overexpressing cells were seeded (25,000 cells/well) into black Poly-D-Lysine coated clear bottom 96-well plates (BD Biosciences, Cat #356640) and incubated overnight at 37° C./5% CO2 in a humidified incubator. Media was aspirated and cells washed twice with 100 μL assay buffer (1×HBSS, 20 mM HEPES) containing 2.5 mM Probenecid. A 0.3× Fluo-4 NW calcium dye was prepared in assay buffer containing 5 mM Probenecid and stored in the dark. Each well was loaded with 100 μL of 0.3× Fluo-4 NW calcium dye and incubated at 37° C./5% CO2 for 60 minutes and then at room temperature for 30 minutes. A half-log serially diluted concentration response curve was prepared at a 3× final assay concentration for each compound (10 μM-0.1 nM final assay concentration) and 50 μL of the compound then transferred to the cells (150 μL final volume) for 60 minutes prior to stimulation (30 minutes at 37° C./5% CO2 and 30 minutes at room temperature). TECK was diluted to 4× its EC80 in assay buffer (containing 0.1% [w/v] bovine serum albumin [BSA]) and 50 μL dispensed through the fluorometric imaging plate reader (FLIPR) instrument to stimulate the cells (200 μL final volume). The increase in intracellular calcium levels was measured with the FLIPR instrument.
- Human P2X3 Receptor Inhibition Assay Stably expressing cell line (C6BU-1 transfected with human P2X3 receptor gene (GenBank accession number Y07683) was used. The cells were seeded in a 96-well microtiter plate at a concentration of 8000 cells/well and cultured in the medium (8.3% fetal bovine serum, 8.3% horse serum, 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 10% BSA, and 0.08% Pluronic F-127, pH 7.5) and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 2.7 KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH 7.5), each well was added with 40 μL of this buffer. The plate was placed in High-Throughput Screening System FDSS 3000 (Hamamatsu Photonics K.K.). Measurement of fluorescence intensity by FDSS 3000 was started, and 40 μl, of DMSO solutions containing different concentrations of the test, compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.1.% Pluronic F-127, pH 7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 50 nM ATP solution (50 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 3 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement. The 50% inhibitory concentration (IC50) was calculated under the assumption that the specific maximum fluorescence intensity without test compound is 0% inhibition and that the specific maximum fluorescence intensity when the dilution buffer was added in place of ATP solution is 100% inhibition, to evaluate the inhibitory activity of the test compound. FDSS software (Hamamatsu Photonics K.K.) was used for calculation of the specific maximum fluorescence intensity. IC50 was calculated using Microsoft Excel (Microsoft Corporation) and Ltd.).
- Humna P2X3 Binding Assay Stably expressing cell line (C6BU-1 cell transfected with human P2X3 receptor gene (GenBank accession number Y07683) was used. The cells were seeded in a 384-well PDL-coated microtiter plate at a concentration of 3000 cells/well and cultured in the medium (8.3% fetal bovine serum, 8.3% horse serum, and 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.5% BSA, and 0.04% Pluronic F-127, pH 7.5) and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH7.5), and each well was added with 20 μL of the washing buffer. The plate was placed in High-Throughput Screening System FLIPR 384 (Molecular Device Co.). Measurement of fluorescence intensity by FLIPR 384 was started, and 20 μL of DMSO solutions containing different concentrations of the test compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.1% Pluronic F-127, pH7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 150 nM ATP solution (25 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 4 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement. The 50% inhibitory concentration (IC50) was calculated under the assumption that the specific maximum fluorescence intensity without test compound is 0% inhibition and that the specific maximum fluorescence intensity when the dilution buffer was added in place of ATP solution is 100% inhibition, to evaluate the inhibitory activity of the test compound. The specific maximum fluorescence intensity and IC50 were calculated using Spotfire (Science & Technology Systems, Inc.)
- Receptor Inhibition Assay Stably expressing cell line (C6BU-1 cell transfected with human P2X3 receptor gene (GenBank accession number Y07683) was used. The cells were seeded in a 384-well microtiter plate at a concentration of 3000 cells/well and cultured in the medium (7.0% fetal bovine serum, 7.0% horse serum, 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (20 mM HEPES, 1.37 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.5% BSA, and 0.04% Pluronic F-127, pH 7.5) and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH7.5), and each well was added with 20 μL of this buffer. The plate was placed in High-Throughput Screening System FLIPR 384 (Molecular Device Co.). Measurement of fluorescence intensity by FLIPR 384 was started, and 20 μL of DMSO solutions containing different concentrations of the test compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.1% Pluronic F-127, pH 7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 150 nM ATP solution (25 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 4 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement. The 50% inhibitory concentration (IC50) was calculated under the assumption that the specific maximum fluorescence intensity without test compound is 0% inhibition and that the specific maximum fluorescence intensity when the dilution buffer was added in place of ATP solution is 100% inhibition, to evaluate the inhibitory activity of the test compound.
- Cell-Based Functional Assay HEK cells transfected with the human mGluR5a receptor (H10H cell line) were plated at 15,000 cells/well in clear-bottomed poly-D-lysine-coated assay plates (BD Falcon) in glutamate-glutamine-free growth medium and incubated overnight at 37° C. and 5% CO2. The following day, the growth medium was removed and the cells were washed with assay buffer containing 1× Hank's balanced salt solution (Invitrogen, Carlsbad, Calif.), 20 mM HEPES, 2.5 mM probenecid, pH 7.4 and left with 20 μL of this reagent. Following this step, the cells were loaded with calcium indicator dye, fluo-4 AM, to a final concentration of 2 μM and incubated for 40-45 min at 37° C. The dye solution was removed and replaced with assay buffer.
- FLIPR Assay FLIPR (Fluorimetric Imaging Plate Reader, Molecular Devices) assays were performed to measure agonist-induced calcium mobilization of the stable clones. For the FLIPR assay, one day before assay, GPR40/CHO NFAT BLA cells were seeded into black-wall-clear-bottom 384-well plates (Costar) at 1.4×10e4 cells/20 μL medium/well. The cells were incubated with 20 μl/well of the assay buffer (HBSS, 0.1% BSA, 20 mM HEPES, 2.5 mM probenecid, pH 7.4) containing 8 μM fluo-4,AM, 0.08% pluronic acid at room temperature for 100 minutes. Fluorescence output was measured using FLIPR. Compounds were dissolved in DMSO and diluted to desired concentrations with assay buffer. 13.3 μL/well of compound solution was added.
- FLIPR Assays FLIPR (Fluorimetric Imaging Plate Reader, Molecular Devices) assays were performed to measure agonist-induced calcium mobilization of the stable clones. For the FLIPR assay, one day before assay, GPR40/CHO NFAT BLA cells were seeded into black-wall-clear-bottom 384-well plates (Costar) at 1.4×10e4 cells/20 μL medium/well. The cells were incubated with 20 μl/well of the assay buffer (HBSS, 0.1% BSA, 20 mM HEPES, 2.5 mM probenecid, pH 7.4) containing 8 μM fluo-4, AM, 0.08% pluronic acid at room temperature for 100 minutes. Fluorescence output was measured using FLIPR. Compounds were dissolved in DMSO and diluted to desired concentrations with assay buffer. 13.3 μL/well of compound solution was added.
- Antagonistic Activity Assay The antagonistic activities of the test compounds on human orexin-1 receptor (hOX1R) and orexin-2 receptor (hOX2R) were measured by modifying from the method described in literature (Toshikatsu Okumura et al., Biochemical and Biophysical Research Communications 280, 976-981, 2001). Chinese hamster ovary (CHO) cells forcibly expressing the hOX1R and hOX2R were seeded into a 96 well Black clear bottom plate (Nunc) at 20,000 cells per well, which were cultured in Ham's F-12 medium containing 0.1 mM MEM non-essential amino acids, 0.5 mg/ml G418, 10% fetal bovine serum (all by Invitrogen) for 16 hours under the conditions of 37° C., 5% CO2. After removing the medium, 100 uL of 0.5 uM Fluo-4AM ester (Dojin) in an assay buffer (25 mM HEPES (Dojin), Hank's balanced salt solution (Invitrogen), 0.1% bovine serum albumin, 2.5 mM probenecid, 200 ug/ml Amaranth (all by Sigma-Aldrich), pH 7.4) was added and the cells were incubated for 60 minutes at 37° C., 5% CO2. After removing the medium, 100 uL of 0.5 uM Fluo-4AM ester (Dojin) in an assay buffer (25 mM HEPES (Dojin), Hank's balanced salt solution (Invitrogen), 0.1% bovine serum albumin, 2.5 mM probenecid, 200 ug/ml Amaranth (all by Sigma-Aldrich), pH 7.4) was added and the cells were incubated for 60 minutes at 37° C., 5% CO2. After removing the assay buffer containing fluo-3AM ester, the test compound was dissolved in dimethyl sulfoxide to be 10 mM and diluted with the assay buffer, 150 uL of which was added and incubated for 30 minutes.
- Humna P2X3 Binding Assay in Human Serum Albumin (HSA) Stably expressing cell line (C6BU-1 cell transfected with human P2X3 receptor gene (GenBank accession number Y07683) was used. The cells were seeded in a 96-well microtiter plate at a concentration of 8000 cells/well and cultured in the medium (7.0% fetal bovine serum, 7.0% horse serum, 1% antibiotic and antifungal, and 2.0% glutamine in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (20 mM HEPES, 137 mM NaCl, 5.37 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.5% BSA, and 0.04% Pluronic F-127, pH 7.5) and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH7.5), and each well was added with 40 μL of this buffer. The plate was placed in High-Throughput Screening System FDSS 3000 (Hamamatsu Photonics K.K.). Measurement of fluorescence intensity by FDSS 3000 was started, and 40 μL of DMSO solutions containing 1% HSA (final concentrations) different concentrations of the test compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.1% Pluronic F-127, pH7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 50 nM ATP solution (50 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 4 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement. The 50% inhibitory concentration (IC50) was calculated under the assumption that the specific maximum fluorescence intensity without test compound is 0% inhibition and that the specific maximum fluorescence intensity when the dilution buffer was added in place of ATP solution is 100% inhibition, to evaluate the inhibitory activity of the test compound. FDSS software (Hamamatsu Photonics K.K.) was used for calculation of the specific maximum fluorescence intensity. IC50 was calculated using Microsoft Excel (Microsoft Corporation) and XLfit (idbs Ltd.)
- NK-1, NK-2 and NK-3 Calcium Flux FLIPR assays Experimental procedure for NK-1, NK-2 and NK-3 calcium flux FLIPR assay: Perform the assay in the following steps: 1) Cell preparation: thaw each cell (NK-1, NK-2 and NK-3) in 37° C. water bath with gentle shaking, transfer cell suspensions to 50 mL conical tubes and add plating media to 45 mL mark. Count cells using a ViCell for concentration. Re-suspend the cells in the growth media to a concentration of 10×105 per mL. Add 20 μL per well of the cell suspension to the 384-well plates (20,000 cells/well). Place the cells at 37° C. 5% CO2 incubator overnight. 2) Calcium Flux FLIPR assay: a) Prepare Probenecid reagent by adding 1 mL FLIPR Assay Buffer to 77 mg probenecid to make 250 mM solution. b) Prepare assay reagent (2×8 μM Fluo-4 Direct Loading Buffer): Thaw one vial of Fluo-4 Direct crystals, add 10 mL of FLIPR Assay Buffer to the Vial; add 0.2 mL of Probenecid to each 10 mL vial of Fluo-Direct. c) Compounds preparation: The compounds are serially diluted in 100% DMSO 1:3 for 10 pts by Echo. Then dispense 900 nL of compounds to the 384-compound plate. Remove cell plate from incubator and gently dispense 20 μL of 2×Fluo-4 Direct to 384 well cell culture plate. Incubate for 50 min at 37° C. 5% CO2 and 10 min at room temperature. Remove cell plate from incubator and place it into FLIPR (Molecular Devices). Place compound plate and tip box into FLIPR. For the dose response curve (DRC) plate: a) Run the Protocol on FLIPRTETRA. b) Transfer 10 μL of assay buffer from 384-well plate to the cell plates. c) Read fluorescence signal. d) Transfer 10 μL of the compounds from the DRC plate to the cell plates. e) Read fluorescence signal. f) Calculate the Max-Min starting from Read 90 to Maximum allowed. Calculate the EC80 values for each cell line using FLIPR. g) Prepare 6×EC80 concentrations of agonist reference compounds. For the compound plate in antagonist test: a) Run the Protocol on FLIPRTETRA. b) Transfer 10 μL of references and compounds from the compound plate to the cell plates. c) Read fluorescence signal. d) Transfer 10 μL of 6×EC80 concentrations of agonist reference compounds to the cell plates. e) Read fluorescence signal. f) For antagonist test, calculate the Max-Min starting from Read 90 to Maximum allowed. h) Analyze the data using GraphPad Prism 5.0.
- Rat P2X3 Binding Assay Rat P2X3 receptor gene (GenBank accession number NM_031075) was expressed in C6BU-1 cell. The C6BU-1 cells were seeded in a 96-well microtiter plate at a concentration of 2500 cells/well and cultured in the medium (7.0% fetal bovine serum, 7.0% horse serum, and 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. The plasmid was transfected into the cells using transfection reagent FuGENE6 (Promega). The transfected cells were cultured in the medium for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (pH7.5) containing 20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 1% BSA, and 0.08% Pluronic F-127, and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH7.5), and each well was added with 40 μL of this buffer. The plate was placed in High-Throughput Screening System FDSS 3000 (Hamamatsu Photonics K.K.). Measurement of fluorescence intensity by FDSS 3000 was started, and 40 μL of DMSO solutions containing different concentrations of the test compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.1% Pluronic F-127, pH7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 50 nM ATP solution (50 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 4 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement. The 50% inhibitory concentration (IC50) was calculated under the assumption that the specific maximum fluorescence intensity without test compound is 0% inhibition and that the specific maximum fluorescence intensity when the dilution buffer was added in place of ATP solution is 100% inhibition, to evaluate the inhibitory activity of the test compound. FDSS software (Hamamatsu Photonics K.K.) was used for calculation of the specific maximum fluorescence intensity. IC50 was calculated using Microsoft Excel (Microsoft Corporation) and XLfit (idbs Ltd.).The data of the compounds of the present invention ar
- Rat P2X3 Binding Assay in Rat Serum Albumin (HSA) Rat P2X3 receptor gene (GenBank accession number NM_031075) was expressed in C6BU-1 cell. The C6BU-1 cells were seeded in a 96-well microtiter plate at a concentration of 2500 cells/well and cultured in the medium (7.0% fetal bovine serum, 7.0% horse serum, and 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. The plasmid was transfected into the cells using transfection reagent FuGENE6 (Promega). The transfected cells were cultured in the medium for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-4-AM solution (pH7.5) containing 20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 10% BSA, and 0.08% Pluronic F-127, and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH7.5), and each well was added with 40 μL of this buffer. The plate was placed in High-Throughput Screening System FDSS 3000 (Hamamatsu Photonics K.K.). Measurement of fluorescence intensity by FDSS 3000 was started, and 40 μL of DMSO solutions containing 1% RSA (final concentrations) and different concentrations of the test compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM NaCl, 5.27 mM KCl, 0.9 mM MgCl2, 1.26 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.1% Pluronic F-127, pH7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 50 nM ATP solution (50 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 4 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement. The 50% inhibitory concentration (IC50) was calculated under the assumption that the specific maximum fluorescence intensity without test compound is 0% inhibition and that the specific maximum fluorescence intensity when the dilution buffer was added in place of ATP solution is 100% inhibition, to evaluate the inhibitory activity of the test compound. FDSS software (Hamamatsu Photonics K.K.) was used for calculation of the specific maximum fluorescence intensity. IC50 was calculated using Microsoft Excel (Microsoft Corporation) and XLfit (idbs Ltd.).
- Orexin Receptor Cell-Based Functional Assay Measurement of [Ca2+]i using a FLIPR: CHO OX1 or CHO OX2 cells were seeded into black-walled clear-base 384-well plates (Corning, catalog #3712) at a density of 20,000 cells per well in F12-K medium supplemented with 10% FBS and then incubated in a 5% CO2, 37° C. incubator overnight to reach 90% confluency. The cells were incubated with equal volume of calcium 6 loading buffer (Molecular Devices, Inc.) containing 2.5 mM probenecid at 37° C. for 2 h, followed by test compounds (dose-range 0.1 nM-10 μM) for another 30 min. The plates were then placed into a FLIPR (Molecular Devices, Inc.) to monitor fluorescence (λ excitation 488 nm, λ emission 540 nm) before and after the addition of EC90 of [OX].
- Biological Assay Prokineticin receptor 1 (PKR1) antagonists may be functionally assessed by measurement of change in intracellular calcium levels induced by Gq mediated increase in inositol triphosphate (IP3) levels. The ability of a compound to block the intracellular release of calcium mediated by PK1 in RBL2H3 cells expressing human PKR1 receptors is determined as a measure of the compound's antagonist activity in vitro.Approximately 10,000 cells per assay well are seeded in normal culture medium in a 384 well plate (Corning). Twenty-four hours after seeding, the cells are loaded with a calcium sensitive fluorescent dye by replacing the culture medium with assay buffer (1× Hanks buffered saline, 25 mM HEPES, 0.1% w/v fatty acid free BSA (bovine serum albumin), pH 7.4) containing 1 mM probenecid and 1× Calcium 5 Reagent (Molecular Devices). Cells are incubated at 37° C. for 1 hour to allow for dye uptake.
- Ca2+ Flux Assay G ±15 HEK293 cells stably expressing rat mGlu2 were plated in black-walled, clear-bottomed, poly-D-lysine coated 384-well plates in 20 L of assay medium (DMEM containing 10% dialyzed FBS, 20 mM HEPES, and 1 mM sodium pyruvate) at a density of 12K cells/well. The cells were grown overnight at 37 ° C. in the presence of 5% CO2. The next day, medium was removed and the cells incubated with 20 L of 2.3 M Fluo-4, AM prepared as a 2.3 mM stock in DMSO and mixed in a 1:1 ratio with 10% (w/v) pluronic acid F-127 and diluted in assay buffer (Hank's balanced salt solution, 20 mM HEPES, and 2.5 mM probenecid) for 45 minutes at 37 ° C. Dye was removed, 20 L of assay buffer was added, and the plate was incubated for 5 minutes at room temperature.
- FLIPR Assay HEK 293 Cells were grown in media containing DMEM, 10% FBS pen/strep/L-Glutamine and non-essential amino acids. The cells were plated in 384-well PDL coated plates at 12000 cells/well and incubated overnight at 37° C./5% CO2. Media was then removed from the cells, which were then incubated with buffer (Hank's containing HEPES and Chaps) containing FLIPR calcium-5 dye, made with buffer containing probenecid, for 60 minutes at 37° C. Varying concentrations of compound in a final concentration of 5% DMSO were then added to the cells and incubated at 25° C. for 30 minutes. The plates were then added to the FLIPR Tetra and the device added a concentration of a PAR1 selective receptor-activating peptide with the sequence Ala-parafluoroPhe-Arg-Cha-Cit-Try-Nh2 (prepared in water) at a concentration equal to the effective concentration that achieves 80% activation of signaling on the day of the experiment.
- Rat P2X3 Receptor Inhibition Assay Rat P2X3 receptor gene (GenBank accession number NM_031075) was expressed in C6BU-1 cell. The cells stably expressing rat P2X3 were seeded in a 96-well microtiter plate at a concentration of 8000 cells/well and cultured in the medium (8.3% fetal bovine serum. 8.3% horse serum, 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. In transiently expressing system, the C6BU-1 cells were seeded in a 90-well microliter plate at a concentration of 2500 cells/well and cultured in the medium for one day at 37° C. under 5% carbon dioxide atmosphere. The plasmid was transfected into the cells using transfection reagent FuGENE6 (Roche). The transfected cells were cultured in the medium for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (pH 7.5) containing 20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 10% BSA, and 0.08% Pluronic F-127, and incubated at 37° C. under 5% dioxide carbon atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH 7.5), and each well was added with 40 μL of this buffer. The plate was placed in High-Throughput Screening System FDSS 3000 (Hamamatsu Photonics K.K.). Measurement of fluorescence intensity by FDSS 3000 was started, and 40 μL of DMSO solutions containing different concentrations of the test compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 0.1% Pluronic F-127, pH 7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 50 mM ATP solution (50 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 3 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement. The 50% inhibitory concentration (IC50) was calculated under the assumption that the specific maximum fluorescence intensity without test compound is 0% inhibition and that the specific maximum fluorescence intensity when the dilution buffer was added in place of ATP solution is 100% inhibition, to evaluate the inhibitory activity of the test compound. FDSS software (Hamamatsu Photonics K.K.) was used for calculation of the specific maximum fluorescence intensity. IC50 was calculated using Microsoft Excel (Microsoft Corporation) and XLfit (idbs Ltd.).
- Rat P2X3 Receptor Inhibition RSA Assay Rat P2X3 receptor gene (GenBank accession number NM_031075) was expressed in C6BU-1 cell. The cells stably expressing rat P2X3 were seeded in a 96-well microtiter plate at a :concentration of 8000 cells/well and cultured in the medium (8.3% fetal bovine serum, 8.3% horse serum, 1% antibiotic and antifungal in DMEM) for one day at 37° C. under 5% carbon dioxide atmosphere. In transiently expressing system, the C6BU-1 cells were seeded in a 96-well microtiter plate at a concentration of 2500 cells/well and cultured in the medium for one day at 37° C. under 5% carbon dioxide atmosphere. The plasmid was transfected into the cells using transfection reagent FuGENE6 (Roche). The transfected cells were cultured in the medium for one day at 37° C. under 5% carbon dioxide atmosphere. The medium was replaced with 4 μM Fluo-3-AM solution (pH 7.5) containing 20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, 10% BSA, and 0.08% Pluronic F-127, and incubated at 37° C. under 5% carbon dioxide atmosphere for one hour. The plate was washed with washing buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.6 mM D-glucose, 2.5 mM probenecid, pH 7.5), and each well was added with 40 μL of this buffer. The plate was placed in High-Throughput Screening System FDSS 3000 (Hamamatsu Photonics K.K.). Measurement of fluorescence intensity by FDSS 3000 was started, and 40 μL of DMSO solutions containing 1% RSA (final concentrations) and different concentrations of the test compound as prepared by dilution with dilution buffer (20 mM HEPES, 137 mM NaCl, 2.7 mM KCl, 0.9 mM MgCl2, 5.0 mM CaCl2, 5.0 mM D-glucose, 2.5 mM probenecid, 0.1% Pluronic F-127, pH 7.5) were dispensed to each well through the built-in automatic dispenser. Five minutes after, 50 nM ATP solution (50 μL) prepared by dilution with the dilution buffer was dispensed through the built-in automatic dispenser, and the measurement of fluorescence intensity was continued for 3 min. For each well, the specific maximum fluorescence intensity was calculated as the ratio of the maximum fluorescence intensity after addition of the ATP solution to the fluorescence intensity at the starting of the measurement. The 50% inhibitory concentration (IC50) was calculated under the assumption that the specific maximum fluorescence intensity without test compound is 0% inhibition and that the specific maximum fluorescence intensity when the dilution buffer was added in place of ATP solution is 100% inhibition, to evaluate the inhibitory activity of the test compound. FDSS software (Hamamatsu Photonics K.K.) was used for calculation of the specific maximum fluorescence intensity. IC50 was calculated using Microsoft Excel (Microsoft Corporation) and XLfit (idbs Ltd.).
- Fluorescent Imaging Plate Reader (FLIPR) Assay Briefly, 293-human or mouse P2X7 stable cells were incubated in sucrose buffer, pH 7.4 [KCl (5 mM), NaH2PO42H2O (9.6 mM), HEPES (25 mM), sucrose (280 mM), glucose (5 mM), CaCl2 (0.5 mM), and probenecid (0.1425 g in 3 mL 1N NaOH was added for 500 mL solution)] in 384-well plates. 93-rat P2X7 stable cells were incubated in HHPB (pH 7.4) [consisting of Hank's BSS (1X); HEPES (pH 7.4) (20 mM) (Sigma); probenecid (0.710 g/5 mL 1N NaOH) (Sigma); and BSA (0.05%) (Roche) which was added after the pH had been adjusted] in 384-well plates. Fluo-4 NW dye mix (Molecular Probes, Inc., Eugene, Oreg., USA) was prepared in buffer (see manufacturer's instructions). Cell plates were removed from the 37° C. incubator, the media discarded and then 30 μL of dye was added to each well. Plates were placed in the 37° C., non-CO2 incubator for 30 minutes and then room temperature for 30 minutes. Two sets of drug plates were prepared: A) Mixtures of compound plus agonist were prepared as follows, in order to determine close response: BzATP: 11 point ½ log, diluted in buffer, starting from 1 mM. Testing compounds: 11 point ½ log, diluted in 2% DMSO buffer starting from 10 μM. B) Agonist only mixture was prepared with BzATP at a single concentration in buffer (concentration determined by dose response). Compound mixtures (A) were added to assay plates containing cells and placed at room temperature for 30 minutes, then BzATP (B) was added. Fluorescence was read using the Tetra FLIPR® (Molecular Devices, Inc., Sunnyvale, Calif., USA) and IC50 values were calculated by standard methods to determine antagonist activity.
- pH Assay Culture medium was removed using an 8-channel-pipette (Rainin, USA) from the 96-well plate and the wells were refilled with 100 μL of loading buffer (20 mM HEPES, 115 mM NaCl, 5.4 mM KCl, 0.8 mM MgCl2, 1.8 mM CaCl2, 13.8 mM D-glucose, 2.5 mM probenecid, pH 7.4) containing 5 M Fura-2 AM (Dojin, Japan). The 96-well plate was incubated at 37° C. for 45 min. The cells were washed twice with 150 μL of measuring buffer (mentioned in step 2.2.(3) of Protocol 2, no probenecid). The wells were subsequently refilled with 70 μL of measuring buffer. Either 10 μL of measuring buffer or 10 μL of 10× stock serial dilution of test compound (described in step 3.2. above) were applied to each well. Usually, only one test compound was tested per 96-well plate. The number of replicates per 96-well plate for a particular antagonist at a particular concentration was 2×7 since, as described for the "agonist plate," two different sulfuric acid concentrations were used per 96-well plate and seven lanes (A-C, E-H) per 96-well plate were used (N=2×7). After an incubation at 4° C. for 15 min, the 96-well plate was transferred to a model FDSS-3000 plate reader apparatus (Hamamatsu Photonics K.K., Japan). Fura-2 fluorescent intensity was monitored as described in step 2.2.(5) above. After 16 time points of baseline detection, 20 μL of agonist solution (measuring buffer titrated with H2SO4 to yield a pH in the range of from about 5.0 to about 5.1 when mixed 1:4 with the measuring buffer containing test compound) was added to each well (final volume 100 μL/well).
- Antagonism of Humanized OX2 Receptor Assay The capability of the compounds to antagonism of humanized OX2 receptor transfected by the HEK-293 cells was evaluated by the method of fluorescence detected free calcium concentration in the cytoplasm. The cells were suspended in cell culture medium (invitrogen), and then added to a microplate with an average density of 3×104 cells/well. The fluorescent probes (Fluo4 NW, Invitrogen) was mixed with probenecid Hank's balanced salt solution (invitrogen), followed by addition of 20 mM hydroxyethyl piperazine acetic sulfuric acid (invitrogen) (pH 7.4). The resulting mixture was eventually added to the microwells containing cells. The cells were incubated at 37° C. for 60 min, and then balanced at 22° C. for 15 min. The microplate was placed in a microplate reader (CellLux, PerkinElmer), and the solution of test compound with different concentrations or Hank's balanced salt solution was added. The microplate containing the solution was incubated for 5 min, followed by the addition of 10 nM of orexin B or a balanced salt solution (as control). The changes of fluorescence intensity proportional to the concentration of calcium ions in the cytoplasm were measured.
- GRP40 FLIPR Assays FLIPR (Fluorimetric Imaging Plate Reader, Molecular Devices) assays were performed to measure agonist-induced calcium mobilization of the stable clones. For the FLIPR assay, one day before assay, GPR40/CHO NFAT BLA cells were seeded into black-wall-clear-bottom 384-well plates (Costar) at 1.4×10e4 cells/20 μL medium/well. The cells were incubated with 20 μl/well of the assay buffer (HBSS, 0.1% BSA, 20 mM HEPES, 2.5 mM probenecid, pH 7.4) containing 8 μM fluo-4, AM, 0.08% pluronic acid at room temperature for 100 minutes. Fluorescence output was measured using FLIPR. Compounds were dissolved in DMSO and diluted to desired concentrations with assay buffer. 13.3 μL/well of compound solution was added.The compounds of the present invention, including the compounds in Examples 1-159, have EC50 values less than 2 micromolar (μM) in the FLIPR assay described above
- In Vitro Assay Human orexin-A as an agonist is prepared as 1 mM stock solution in MeOH: water (1:1), diluted in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/l and 20 mM HEPES for use in the assay at a final concentration of 3 nM.Antagonists are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates using DMSO followed by a transfer of the dilutions into in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/l and 20 mM HEPES. On the day of the assay, 50 μl of staining buffer (HBSS containing 1% FCS, 20 mM HEPES, NaHCO3: 0.375 g/l, 5 mM probenecid (Sigma) and 3 μM of the fluorescent calcium indicator fluo-4 AM (1 mM stock solution in DMSO, containing 10% pluronic) is added to each well. The 384-well cell-plates are incubated for 50 min at 37° C. in 5% CO2 followed by equilibration at RT for 30 min before measurement.
- Thallium Flux Assay FluxOR Kit Components (Invitrogen F10017) FluxOR Reagent (Component A) FluxOR Assay Buffer (Component B)-10x Concentrate PowerLoad Concentrate (Component C)-100x Concentrate Probenecid (Component D)-Lyophilized sample is kept at -20 C. Water soluble, 100x after solubilization in 1 ml water. Store at 4 C. FluxOR Chloride-free Buffer (Component E)-5x Concentrate Potassium sulfate (K2SO4) Concentrate (Component F)-125 mM in water. Store at 4 C. Thallium sulfate (Tl2SO4) Concentrate (Component G)-50 mM in water. Store at 4 C. DMSO (dimethyl sulfoxide, Component H)-1 ml (100%) Reagent Preparation- FluxOR Working Solutions 1000x FluxOR Reagent: Reconstitute a vial of component A in 100 ul DMSO; Mix well; Store 10 ul aliquots at -20 C. 1x FluxOR Assay Buffer: Dilute Component B 10-fold with water; Adjust pH to 7.4 with Hepes/NaOH; Filter and store at 4 C.
- Binding Assay Cell culture: 293 HEK cells, stably transfected with plasmids capable of expressing human P2X7 receptor, were cultured by standard methods. Cells were plated to cell density of approximately 15,000 cells/well in 384-well assay plates (50 μl/well) with 1.5% low serum media (DMEM, 1.5% BCS, 1% L-glut (2 mM), 1% P/S).293 HEK cells, stably transfected with plasmids capable of expressing rat or mouse P2X7 receptor, were cultured by standard methods. Cells were plated to cell density of approximately 15,000 cells/well in 384-well assay plates (50 μl/well) with 1.5% low serum media (DMEM, 1.5% FBS, 1% L-glut (2 mM), 10 mM HEPES, 1% P/S). Cells were plated 24 hours prior to assay. Cells expressing human, rat or mouse P2X7 receptor were assayed in the following manner.Fluorescent Imaging Plate Reader (FLIPR) assay: Briefly, 293-human or mouse P2X7 stable cells were incubated in sucrose buffer, pH 7.4 [KCl (5 mM), NaH2PO4.2H2O (9.6 mM), HEPES (25 mM), sucrose (280 mM), glucose (5 mM), CaCl2 (0.5 mM), and probenecid (0.1425 g in 3 mL 1N NaOH was added for 500 mL solution)] in 384-well plates.293-rat P2X7 stable cells were incubated in HHPB (pH 7.4) [consisting of Hank's BSS (1×); HEPES (pH 7.4) (20 mM) (Sigma); probenecid (0.710 g/5 mL 1N NaOH) (Sigma); and BSA (0.05%) (Roche) which was added after the pH had been adjusted] in 384-well plates. Fluo-4 NW dye mix (Molecular Probes, Inc., Eugene, Oreg., USA) was prepared in buffer (see manufacturer's instructions). Cell plates were removed from the 37° C. incubator, the media discarded and then 30 μL of dye was added to each well. Plates were placed in the 37° C., non-CO2 incubator for 30 minutes and then room temperature for 30 minutes.
- Antagonism of Humanized OX1 Receptor Assay The capability of the compounds to the antagonism of humanized OX1 receptor transfected to the Chinese hamster ovary (CHO) cells was evaluated by the method of fluorescence detected free calcium concentration in the cytoplasm. The cells were suspended in a cell culture medium (invitrogen), and then plated to a microplate with an average density of 2×104 cells/well. The fluorescent probes (Fluo4 NW, Invitrogen) was mixed with probenecid Hank's balanced salt solution (invitrogen), followed by addition of 20 mM hydroxyethyl piperazine acetic sulfuric acid (invitrogen) (pH 7.4). The resulting mixture was eventually added to the microwells containing cells. The cells were incubated at 37° C. for 60 min, and then balanced at 22° C. for 15 min. The microplate was placed in a microplate reader (CellLux, PerkinElmer), and the solution of test compound with different concentrations or Hank's balanced salt solution was added. The microplate containing the solution was incubated for 5 min, followed by the addition of 3 nM of orexin A or a balanced salt solution (as control). The changes of fluorescence intensity proportional to the concentration of calcium ions in the cytoplasm were measured.
- FLIPR Assay Compounds were tested for their ability to inhibit C5a-mediated calcium mobilization using a stable cell line over expressing the human C5aR & the Galpha 15 protein on the FLIPR (Fluorescent Imaging Plate Reader) Tetra system. Cells were maintained in culture media containing DMEM (Dulbecco's Modified Eagle Medium) with 4.5 g/L glucose, 10% fetal bovine serum, 100 U/mL, 1x non-essential amino acid, and 250 ug/mL G418 (Geneticin). Prior to testing of compounds, cells were plated at 10,000 cells/well in clear bottom 384-well black plate, and incubated overnight at 37C. with 5% CO2. On the day of experiment, culture media was removed, and replaced with assay buffer HBSS (Hanks' Balanced Salt Solution) with 20 mM HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) and 0.1% BSA (bovine serum albumin) BSA containing calcium 5 dye (Molecular Devices) and 2.5 mM probenecid. After 1 hour incubation at 37C., 5% CO2 for 60 min, cells were pre-incubated with compounds for 30 minutes.
- In Vitro Assay for Determining IC50 Compounds were prepared in DMSO (stock concentration: 1 mM) and 3×serially diluted (10 concentrations) in 384-LDV plate (Labcyte). Ninety nL of serially diluted compounds were transferred from 384-LDV plate into compound plate (PerkinElmer) by Echo 550 (Labcyte), and 30 uL assay buffer (1×HBSS with 20 mM HEPES, pH 7.4, Sigma) were added to each well. For FLIPR assay, culture media was removed and 20 uL of 1× loading dye (Assay buffer with 2 μM Fluo-8 AM, AAT Bioquest; 1 mM Probenecid and 0.0025% pluronic F-127, Sigma) was added to each well. The plate was incubated at 37° C. for 1 hr (avoid light exposure). For FLIPR assay, Excitation wavelength was set at 470/495 nm and Emission wavelength was set at 515/575 nm (Molecular Devices). Assay was performed in both agonist and antagonist modes. For agonist mode, 10 μL of diluted compounds were transferred to cell culture well and incubated at room temperature for 10 min.
- In Vitro Binding Assay I. Master Stock SolutionUnless specified otherwise, the sample compounds were diluted in 100% anhydrous DMSO including all dilutions. The compounds were tested as the citrate salt (1 equivalent per molecule). If the sample compound is provided in a different solvent all master stock dilutions are performed in the specified solvent. All control wells contained identical solvent final concentrations as the sample compound wells.II. Compound Plate AssayThe sample compounds were transferred from a master stock solution into a daughter plate that was used in the assay. Each sample compound was diluted into an assay buffer (1×HBSS with 20 mM HEPES, 2.5 mM Probenecid, and 0.4% Free Fatty Acid BSA) at an appropriate concentration to obtain final specified concentrations.III. Antagonist Assay FormatUsing the EC80 values that were determined real-time, stimulated all pre-incubated sample compounds and reference antagonists (if applicable) were compared with the EC80 values of reference agonist. These were read for 180 seconds using the FLIPRTETRA (This assay added reference agonist to respective wells-then fluorescences measurements were collected to calculate IC50 values).
- mGlu3 Ca2+ Flux Assay Gα15/TREx cells stably expressing rat mGlu3 were plated in black-walled, clear-bottomed, poly-D-lysine coated 384-well plates in 20 μL of assay medium (DMEM containing 10% dialyzed FBS, 20 mM HEPES, 25 ng/mL tetracycline, 100 units/mL penicillin/streptomycin plus 250 ng/mL Fungizone, and 1 mM sodium pyruvate) at a density of 15K cells/well. The cells were grown overnight at 37° C. in the presence of 5% CO2. The next day, medium was removed and the cells incubated with 20 μL of 2.3 μM Fluo-4, AM prepared as a 2.3 mM stock in DMSO and mixed in a 1:1 ratio with 10% (w/v) pluronic acid F-127 and diluted in assay buffer (Hank's balanced salt solution, 20 mM HEPES, and 2.5 mM probenecid) for 60 minutes at room temperature. Dye was removed, 20 μL of assay buffer was added, and the plate was incubated for 10 minutes at room temperature.
- mGlu5 Ca2+ Flux Assay HEK 293A cells stably expressing rat mGlu5 were plated in black-walled, clear-bottomed, poly-D-lysine coated 384-well plates in 20 μL of assay medium (DMEM containing 10% dialyzed FBS, 20 mM HEPES, 100 units/mL penicillin/streptomycin plus 250 ng/mL Fungizone, and 1 mM sodium pyruvate) at a density of 20K cells/well. The cells were grown overnight at 37° C. in the presence of 5% CO2. The next day, medium was removed and the cells incubated with 20 μL of 2.3 μM Fluo-4, AM prepared as a 2.3 mM stock in DMSO and mixed in a 1:1 ratio with 10% (w/v) pluronic acid F-127 and diluted in assay buffer (Hank's balanced salt solution, 20 mM HEPES, and 2.5 mM probenecid) for 45 minutes at 37° C. Dye was removed, 20 μL of assay buffer was added, and the plate was incubated for 5 minutes at room temperature.
- FLIPR Ca2+ Flux Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for diluted in 384-well plates, first in DMSO, then assay buffer.
- pH-based Assay pH dependent Ca2+ responses in TRPV1/CHO cells cultured in a 96-well plate were determined (see, e.g., FIG. 2 of U.S. Patent Application Publication No. US 2009/0170868 A1). In particular, Ca2+ influx into TRPV1/CHO cells in response to low pH as measured by Fura-2 AM fluorescence was determined. The cells were stimulated using 3.0 mM (well numbers B1-B6), 3.1 mM (C1-C6), 3.2 mM (D1-D6), 3.3 mM (E1-E6), 3.4 mM (F1-F6), 3.5 mM (G1-G6), or 3.6 mM (H1-H6) H2SO4 or pH 7.2 measuring buffer without H2SO4 (A1-A6). Culture medium was removed using an 8-channel-pipette (Rainin, USA) from the 96-well plate and the wells were refilled with 100 uL of loading buffer (20 mM HEPES, 115 mM NaCl, 5.4 mM KCl, 0.8 mM MgCl2, 1.8 mM CaCl2, 13.8 mM D-glucose, 2.5 mM probenecid, pH 7.4) containing 5 uM Fura-2 AM (Dojin, Japan). The 96-well plate was incubated at 37° C. for 45 min. The loading buffer was removed from each well. The cells were subsequently washed twice with 150 uL of measuring buffer (20 mM HEPES, 115 mM NaCl, 5.4 mM KCl, 0.8 mM MgCl2, 5.0 mM CaCl2, 13.8 mM D-glucose, 0.1% BSA, pH 7.4) (no probenecid). The wells were then refilled with 80 uL of measuring buffer. After an incubation at 4° C. for 15 min, the 96-well plate was transferred to a model FDSS-3000 plate reader apparatus (Hamamatsu Photonics K.K., Japan). The Fura-2 fluorescent intensity was monitored at a wavelength of 340 nm and at 380 nm, respectively, at a rate of 0.5 Hz for a total of 240 seconds. After 16 time points (32 sec) of baseline detection, 20 uL of agonist solution was added to each well. The final volume was 100 uL/well. Fluorescence intensity ratio refers to the fluorescence intensity at 340 nm over the fluorescence intensity at 380 nm at a particular time point. The baseline was set as the average of the fluorescent intensity ratios for the first 16 time points before the addition of agonist solution. The maximum response was the highest fluorescent intensity ratio during the 60 time points following addition of agonist solution.
- Human Orexin 1 Receptor Ca2+ Mobilization Assay CHO cells stably transfected with the human orexin 1 receptor (Genebank accession number NM_001526) were grown to confluency in DMEM/F12, 10% FBS, 1×pen-strep, 400 μg/ml G418. Cells were seeded on to 384-well Packard viewplates at a density of 10,000 cells/well and incubated overnight at 37° C., 5% CO2. The cells were dye-loaded with BD Calcium Assay kit (BD, cat #640178) in HBSS (Gibco, cat #14025-092) with 2.5 mM probenecid and incubated at 37° C., 5% CO2 for 45 min. Cells were pre-incubated with compounds (diluted in DMEM/F-12) for 15-30 minutes before agonist (orexin A, 10 nM) stimulation. Ligand-induced Ca2+ release was measured using a Fluorometric Imaging Plate Reader (FLIPR, Molecular Devices, Sunnyvale, Calif.). Functional responses were measured as peak fluorescence intensity minus basal. The concentration of agonist that produced a half-maximal response is represented by the EC50 value. Antagonistic potency values were converted to apparent pKB values using a modified Cheng-Prusoff correction. Apparent pKB=−log IC50/1+[conc agonist/EC50].
- Human Orexin 2 Receptor Ca2+ Mobilization Assay PFSK-1 cells endogenously expressing the human orexin 2 receptor were grown to confluency in RPMI1640 (Hyclone, cat #30027.02), 10% FBS, 1× pen-strep. Cells were seeded on to 384-well Packard viewplates at a density of 5,000 cells/well and incubated overnight at 37° C., 5% CO2. The cells were dye-loaded with BD Calcium Assay kit (BD, cat #640178) in HBSS (Gibco, cat #14025-092) with 2.5 mM probenecid and incubated at 37° C., 5% CO2 for 45 min. Cells were pre-incubated with compounds (diluted in DMEM/F-12) for 15-30 minutes before agonist (orexin B, 100 nM) stimulation. Ligand-induced Ca2+ release was measured using a Fluorometric Imaging Plate Reader (FLIPR, Molecular Devices, Sunnyvale, Calif.). Functional responses were measured as peak fluorescence intensity minus basal. The concentration of agonist that produced a half-maximal response is represented by the EC50 value. Antagonistic potency values were converted to apparent pKB values using a modified Cheng-Prusoff correction. Apparent pKB=−log IC50/1+[conc agonist/EC50].
- In Vitro Cannabinoid Receptor Activity Assay Chinese Hamster Ovary (CHO) cells stably expressing either human CB1 or CB2 cDNA and the promiscuous G-protein Gαq16 were transferred to each well of a black Costar 96-well optical bottom plate (Corning Corporation). Each plate was incubated at 37 C. for 24 hr to confluence. The culture media was removed from the plates and cells were subsequently loaded with a fluorescent calcium probe (Calcium 5 dye, Molecular Devices) at a final loading concentration of 2 μM in a HBSS-based buffer containing 20 mM HEPES, 1% BSA and 10 μM Probenecid (Sigma) in a total volume of 225 μl. Cells were incubated at 37 C. for 1 hr and then stimulated with various concentrations of a test agent using a FLIPR Tetra plate-reader, which automatically added the agonist at 10 concentration to each well after reading baseline values for 17 sec. Agonist-mediated change in fluorescence (488 nm excitation, 525 nm emission) was monitored in each well at 1 sec intervals for 60 sec and reported for each well. Data were analyzed using Prism software (GraphPad).
- TRPV1 Inhibition Assay Assay buffer preparation: 1 HBSS, 2 mM HEPES, 0.1% BSA plus 2.5 mM freshly prepared probenecid (Invitrogen, #P36400). 25 μl/well assay buffer in 384 well clear plate (cat #782281, Greiner Bio-one) was dispensed with buffer distributor (Multidrop ComB1 from Thermo Scientific). The compounds were in 384 Echo plate (cat #LPL0200, Labcyte) and the starting concentration of compound was 10 mM, then 1 to 3 serial dilution in 100% DMSO, 8 ul/well). 125 nl compounds was transferred to the 384 well plate containing 25 μl/well buffer with Echo 555 Liquid Handler (Labcyte), such that the compound concentration was 5 fold of final concentration. The plate was shook slowly at 40 rpm/min for 10 min to mix. 10 μl of 5 fold compound in the buffer was transferred to the cell plate (containing 20 μl cells and 20 μl dye) using Vertical Pipetting Station 384ST (Agilent Technologies). Six fold of final concentration of NADA (N-arachidonyl dopamine, cat #A8848, Sigma) in the assay buffer was prepared and 30 μl/well was distributed in 384 well clear plate.
- Biological Assay The ability of a compound to block the intracellular release of calcium mediated by PK1 in RBL2H3 cells expressing human PKR1 receptors is determined as a measure of the compound's antagonist activity in vitro.Approximately 10,000 cells per assay well are seeded in normal culture medium in a 384 well plate (Corning). Twenty-four hours after seeding, the cells are loaded with a calcium sensitive fluorescent dye by replacing the culture medium with assay buffer (1× Hanks buffered saline, 25 mM HEPES, 0.1% w/v fatty acid free BSA (bovine serum albumin), pH 7.4) containing 1 mM probenecid and 1× Calcium 5 Reagent (Molecular Devices). Cells are incubated at 37° C. for 1 hour to allow for dye uptake.To test for antagonist activity, test compounds at a final concentration range between 0.32 nM-10 μM (diluted in assay buffer) are added to the assay wells and allowed to incubate for 10 minutes prior to stimulation with PK1. After incubation with test compounds the assay plate is placed in a FLIPR Tetra (Molecular Devices) and PK1 (diluted in assay buffer) is added at the determined EC80 concentration (final). Ligand-dependent changes in intracellular calcium levels are determined by measuring changes in fluorescence of the dye at 525 nM following to excitation at 485 nM.
- Calcium Fluorescence Measurements Cells were seeded into black-walled, clear-bottom, 96-well plates at a density of 80000 cell/well, in RPMI (without Phenol Red, without L-glutamine; Gibco LifeTechnologies, CA) supplemented with 10% dialyzed FBS. Following 18-h incubation with tetracycline, the cells were loaded with 2 mM Ca2+-sensitive fluorescent dye Fluo-4/AM (Molecular Probes) in Hanks' balanced saline solution (HBSS, Gibco LifeTechnologies, CA) with 20 μM Hepes (Sigma) and 2.5 mM probenecid (Sigma), for 1 h at 37° C. The cells were washed three times with HBSS to remove extracellular dye. Fluorescence signals were measured by using the fluorescence microplate reader Flexstation III (Molecular Devices) at sampling intervals of 1.5 s for 60 s.The antagonist potency was determined using the EC80 of the quisqualate used as agonist and the potentiation of mGlu5 activation was determined using the EC20 of the agonist (quisqualate or glutamate). The compounds were applied 10 minutes before the application of the agonist.The negative allosteric modulator activity (expressed as IC50) and the positive allosteric modulator activity (expressed as EC50) of the compounds of the invention for the mGlu5 receptors is between 0.1 and 1000 nM. For instance, and in particular compounds 31 and 48 have an IC50 of 13.5 and 2.02 nM respectively, and compound 34 has an EC50 of 107.2 nM.
- Calcium Mobilization Assay The rmGluR5 or hmGluR5 was stably expressed in a HEK 293 cell line and gown in Dulbecco's Modified Eagle Medium (DMEM) (Invitrogen, Carlsbad, Calif.) with supplements (10% bovine calf serum, 4 mM glutamine, 100 units/mL penicillin, 100 μg/mL streptomycin and 0.75 mM G1418) at 37° C., 5% CO2. Twenty-four hours prior to assay, cells were seeded into 384-well black wall microtiter plates coated with poly-D-lysine. Just prior to assay, media was aspirated and cells dye-loaded (25 μL/well) with 3 μM Fluo-4/0.01% pluronic acid in assay buffer (Hank's Balanced Saline Solution (HBSS)): 150 mM NaCl, 5 mM KCl, 1 mM CaCl2, 1 mM MgCl2, plus 20 mM N-2-Hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES), pH 7.4, 0.1% bovine serum albumin (BSA) and 2.5 mM probenecid) for 1 hour in 5% CO2 at 37° C. After excess dye was discarded, cells were washed in assay buffer and layered with a final volume equal to 30 μL/well. Basal fluorescence is monitored in a fluorometri
- FLIPR Ca2+ Flux Assay FLIPR Ca2+ Flux Assay (Okumura et al., Biochem. Biophys. Res. Comm. 280:976-981, 2001). In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM.
- FLIPR Calcium 6 Assay The dye is diluted with assay buffer (20mM HEPES in 1x HBSS, PH7.4); Probenecid was added to the final concentration of 5 mM; Hi. Vortexed vigorously for 1-2 minutes. Medium is removed from cell plate by flicking the cell plate on towel papers. 10 pl of assay buffer and 10 pl of 2*dye solution is added to each well of the cell plate. The cell plate is placed on plate shaker, the plate was agitated at 600rpm for 2 minutes. The plate is incubated at 37°C for 2 hours followed by additional 15-minute incubation at 25°C. 3*compound in assay buffer is prepared: a. Reference compounds are diluted to required concentration with DMSO. The compounds were added to a 384-well compound plate; b. Serial dilutions are performed; c. 10mM test compounds are added to the compound plate, and 3-fold serial dilutions were performed, d. Transferee 60 nl/well of compounds from source plate to a 384-well compound plate (Coming, 3657) by using an Echo; e. Add 20pl/well assay buffer to the compound plate; f. Mix the plate on plate shaker for 2 mins; The cell plate, compound plate and tips are put into FLIPR, 10pl of 3x compound is transferred to the cell plate per well with FLIPR.
- Functional Assay For functional expression of TRPM8, the full-length cDNA encoding human and rat TRPM8 are subcloned into pCI-NEO mammalian expression vectors. The expression constructs are transiently transfected into HEK293 cells according to the FuGENE 6 Transfection Reagent (ROCHE) instructions. Within twenty-four hours, transiently transfected cells are harvested and either seeded directly into assay plate or cryopreserved for future usage.Transfected cells may be either cryopreserved or freshly transfected and plated into clearbase poly-D-lysine coated 384-well plates (BD Biosciences, NJ, USA) at a density of 10,000 cells per well in culture medium and grown overnight. The following day, all medium is removed and the cells are incubated with 52 uL of 0.5x Calcium 3 Dye (Molecular Devices) prepared in complete assay buffer containing 20 mM HEPES, 0.1% BSA, and 2.5 mM probenecid at 37 ° C. for thirty five minutes. The cells are then incubated for an additional fifteen minutes at room temperature before initiating experiments. Following incubation, plates are inserted into a FDSS instrument, where cells were challenged with compounds of the formula (I) (at varying concentrations) and intracellular Ca2+ are measured for 5 min prior to the addition of icilin at the EC80concentration IC50 values for compounds of the formula (I) are determined from eight point dose-response studies.
- Measuring Agonistic Activity of Compounds in hFPR1-Gα15-CHO and hFPR2-Aq-CHO Cell Cryo-vial containing 6×106 cells (hFPR1-Gα15-CHO or hFPR2-Aq-CHO) was thawed in a 37° C. water bath. Cells were suspended in 10 ml of respective complete growth media (F12(1×) HAM media (Gibco; Cat#11765); 10% HI-FBS (Gibco; Cat#10082); 0.1 mg/ml Hygromycin B (Invitrogen; Cat#10687-010) [for hFPR1 only]; 0.2 mg/ml Zeocin (Invitrogen; Cat#R25001) [for hFPR1 only]; 0.4 mg/ml Geneticin (Gibco; Cat#10131) [for hFPR2-Aq only]; 0.25 mg/ml Zeocin (Invitrogen; Cat#R25001) [for hFPR2-Aq only]) in a 15 ml centrifuge tube. The cell viability was checked with the help of Trypan Blue dye. Upon washing the cells, those were plated in a 384-well sterile clear bottom black plate (Greiner Bioone Cat#781091) so that, each well contained 10,000 cells in 40 μl complete growth media. The plate was incubated in a 5% CO2 incubator at 37° C. for 18 hours.Before assay on the next day, the cell plating media was removed from each well of the plate by decanting and gentle tapping. 30 μl, 0.11 of 0.5× Calcium 5 dye solution (0.5×FLIPR Calcium 5 dye (Molecular devices Cat# R8186); HBSS (Invitrogen; Cat#14025); 20 mM HEPES (Sigma; Cat#H0887); 2.5 mM Probenecid (Sigma; Cat#P8761); 0.025% Pluronic F-127 (Sigma; Cat#P2443); pH adjusted to 7.4) was added to each well. The plate was then incubated at 37° C. for 30 minutes. Following which the plate was equilibrated at room temperature for 10 minutes before placing it in a 384 well FLIPR for assay. Compounds were dissolved in DMSO and serially diluted following 11 point half log (3.16 fold) dilution with a starting concentration of 2 mM (Final assay concentration 10 μM). Aliquots of above mentioned each dilution was mixed with assay buffer (HBSS (Invitrogen; Cat#14025); 20 mM HEPES (Sigma; Cat#H0887); 2.5 mM Probenecid (Sigma; Cat#P8761); 0.05% gelatin (Sigma; Cat#G1890); 0.1% BSA (Sigma; Cat#A3059); pH adjusted to 7.4) just before performing the assay. Compounds were added to the respective wells of the assay ready cell plate with the help of the FLIPR (FLIPR Tetra) and fluorescence readings were captured for 5 minutes to measure any agonistic response of the compounds. The increase in fluorescence readings from the basal reading in presence of the compounds were compared with that of the control wells (wells having no compound) to calculate the agonistic activity of the compounds. The EC50 values of the compounds were determined using the Graph pad Prism software.
- Biological Assay Prokineticin receptor 1 (PKR1) antagonists may be functionally assessed by measurement of change in intracellular calcium levels induced by Gq mediated increase in inositol triphosphate (IP3) levels. The ability of a compound to block the intracellular release of calcium mediated by PK1 in RBL2H3 cells expressing human PKR1 receptors is determined as a measure of the compound's antagonist activity in vitro.Approximately 10,000 cells per assay well are seeded in normal culture medium in a 384 well plate (Corning). Twenty-four hours after seeding, the cells are loaded with a calcium sensitive fluorescent dye by replacing the culture medium with assay buffer (1× Hanks buffered saline, 25 mM HEPES, 0.1% w/v fatty acid free BSA (bovine serum albumin), pH 7.4) containing 1 mM probenecid and 1× Calcium 5 Reagent (Molecular Devices). Cells are incubated at 37° C. for 1 hour to allow for dye uptake.To test for antagonist activity, test compounds at a final concentration range between 0.32 nM-10 μM (diluted in assay buffer) are added to the assay wells and allowed to incubate for 10 minutes prior to stimulation with PK1. After incubation with test compounds the assay plate is placed in a FLIPR Tetra (Molecular Devices) and PK1 (diluted in assay buffer) is added at the determined EC80 concentration (final). Ligand-dependent changes in intracellular calcium levels are determined by measuring changes in fluorescence of the dye at 525 nM following excitation at 485 nM.
- FLIPR Assay For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 pM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA.
- Inhibitory Activity Assay hERG: 1. Materials and Instruments (1) FluxOR potassium ion channel assay (F10016, invitrogen) (2) FlexStation3 microplate reader (molecular devices) (3) hERG/HEK293 cell: HEK293 cell line stably expressing the hERG channel transfected by hERG cDNA (NCBI SEQ ID NO. NM-000238(RC215928, origene)). 2. Experimental Procedure (1) Human hERG/HEK293 cell was seeded on PDL(Poly-D-lysine) coated plates at 25000 cells/well on the previous day; (2) After overnight culture, the plate medium was discarded; then according to FluxOR potassium ion channel detection requirements operation, the dye was added at 100 μL/hole, and then incubated for 90 mins at room temperature; (3) The dye was then decanted and 100 μL of assay buffer containing 100 μL probenecid were added in each well; (4) 1 μL of compound or DMSO was added to the corresponding wells, shocked for 30 seconds, and incubated for 30 mins at room temperature; (5) The plates were placed in a FlexStation3 microplate reader, and then added with stimulation buffer (K2SO4:Tl2SO4:1XFluxOR Chloride-free Buffer:ddH2O=2:1:2:5) at 25 μL/well, then the value was read continuously for 5 mins at EX/EM of 490/525nm immediately; and (6) The IC50 of the present compounds on human hERG ion channel was obtained by data processing software Graphpad.
- Pharmacological Assay 1. Wash each well with 80 microL of assay buffer (20 mM HEPES, 1×HBSS, pH 7.4 adjusted with NaOH) three times and leave 20 microL using plate washer, ELx-405 Select CW (BIO-TEK).2. Add 20 microL of assay buffer containing 2.5 mM probenecid, 0.5 microM Fluo-4-AM (Molecular Probes) and 0.1% Pluronic F-127 to each well.3. Incubate the plate at 37° C. in 5% CO2 for 1 h.4. Wash each well with 80 microL of assay buffer (see below) three times and leave 20 microL using plate washer, ELx-405 Select CW (BIO-TEK).5. Test compounds were prepared at 100× the test concentration in DMSO by serial dilution with Biomek-FX liquid handling instrument. 33× diluted compound solutions in assay buffer were prepared in intermediate compound plate with Biomek-NX liquid handling instrument. A further 3× dilution occurred in below steps 6 and 7.6. Add 20 microL of 33× diluted compound solutions into each well and leave the plate for 10 min under the dark at room temperature.7. Measure activity by FDSS as follows:Set the assay plate on the stacker of FDSS.Start the detection of fluorescence intensity at 540 nm by 480 nm exicitation.After 30 seconds, add 20 microL of assay buffer containing 240 microM BzATP (final concentration 80 microM).
- Receptor Assay Engagement of the LPA1 receptor by its ligand, oleoyl-L- ±-lysophosphatidic acid (LPA), leads to the release of intracellular stores of calcium into the cytoplasm mediated through a Gq-driven increase in inositol triphosphate (IP3) levels. Gq is a heterotrimeric G protein subunit that activates phospholipase C. The ability of test compounds to prevent LPA-driven intracellular release of stored calcium from RH7777 cells expressing human LPA1 receptors was assayed by stimulating the cells with LPA in the presence of various test compounds to measure the test compounds' antagonism, i.e. activity in vitro. Approximately 10,000 cells in normal culture medium (Dulbecco's Modified Eagle Media, 10% Foetal Calf Serum) were dispensed per assay well in a black clear bottom collagen coated 384 well plate (Beckton Dickinson). Cells were allowed to settle for thirty minutes at room temperature before being incubated overnight at 37° C., 5% CO2. Sixteen to twenty hours after dispensing, the cells were loaded with a calcium-sensitive fluorescent dye by replacing the culture medium with assay buffer (1x Hanks buffered saline, 25 mM HEPES, 0.1% w/v fatty acid free BSA (bovine serum albumin), pH7.4) containing 1.25 mM probenecid and 1x Calcium 5 Reagent (Molecular Devices). Cells were incubated at 37° C. for one hour to allow for dye uptake.
- Receptor Assay Engagement of the LPA5 receptor by its ligand, oleoyl-L- ±-lysophosphatidic acid (LPA), leads to the release of intracellular stores of calcium into the cytoplasm mediated through a Gq-driven increase in inositol triphosphate (IP3) levels. Gq is a heterotrimeric G protein subunit that activates phospholipase C.The ability of test compounds to prevent LPA-driven intracellular release of stored calcium from RH7777 cells expressing human LPA5 receptors was assayed by stimulating the cells with LPA in the presence of various test compounds to measure the test compounds' antagonism, i.e. activity in vitro. Approximately 10,000 cells in normal culture medium (Minimal Essential Media, 10% Foetal Calf Serum) were dispensed per assay well in a black clear bottom poly-D-lysine coated 384 well plate (Corning). Cells were allowed to settle for thirty minutes at room temperature before being incubated overnight at 37° C., 5% CO2. Sixteen to twenty hours after dispensing, the cells were loaded with a calcium-sensitive fluorescent dye by replacing the culture medium with assay buffer (1x Hanks buffered saline, 25 mM HEPES, 0.1% w/v fatty acid free BSA (bovine serum albumin), pH7.4) containing 1.25 mM probenecid and 1x Calcium 5 Reagent (Molecular Devices). Cells were incubated at 37° C. for one hour to allow for dye uptake.
- BIOLOGICAL ASSAY Prokineticin receptor 1 (PKR1) antagonists may be functionally assessed by measurement of change in intracellular calcium levels induced by Gq mediated increase in inositol triphosphate (IP3) levels. The ability of a compound to block the intracellular release of calcium mediated by PK1 in RBL2H3 cells expressing human PKR1 receptors is determined as a measure of the compound's antagonist activity in vitro.Approximately 10,000 cells per assay well are seeded in normal culture medium in a 384 well plate (Corning). Twenty-four hours after seeding, the cells are loaded with a calcium sensitive fluorescent dye by replacing the culture medium with assay buffer (1× Hanks buffered saline, 25 mM HEPES, 0.1% w/v fatty acid free BSA (bovine serum albumin), pH 7.4) containing 1 mM probenecid and 1× Calcium 5 Reagent (Molecular Devices). Cells are incubated at 37° C. for 1 hour to allow for dye uptake.To test for antagonist activity, test compounds at a final concentration range between 0.32 nM-10 μM (diluted in assay buffer) are added to the assay wells and allowed to incubate for 10 minutes prior to stimulation with PK1. After incubation with test compounds the assay plate is placed in a FLIPR Tetra (Molecular Devices) and PK1 (diluted in assay buffer) is added at the determined EC80 concentration (final). Ligand-dependent changes in intracellular calcium levels are determined by measuring changes in fluorescence of the dye at 525 nM following excitation at 485 nM. Readings from wells that do not contain antagonist enable percentage inhibition curves to be plotted using 4-parameter fit algorithm and IC50 values are calculated for each test compound.
- Biological Assay Prokineticin receptor 1 (PKR1) antagonists may be functionally assessed by measurement of change in intracellular calcium levels induced by Gq mediated increase in inositol triphosphate (IP3) levels. The ability of a compound to block the intracellular release of calcium mediated by PK1 in RBL2H3 cells expressing human PKR1 receptors is determined as a measure of the compound's antagonist activity in vitro. Approximately 10,000 cells per assay well are seeded in normal culture medium in a 384 well plate (Corning). Twenty-four hours after seeding, the cells are loaded with a calcium sensitive fluorescent dye by replacing the culture medium with assay buffer (1xHanks buffered saline, 25 mM HEPES, 0.1% w/v fatty acid free BSA (bovine serum albumin), pH 7.4) containing 1 mM probenecid and 1x Calcium 5 Reagent (Molecular Devices). Cells are incubated at 37° C. for 1 hour to allow for dye uptake.To test for antagonist activity, test compounds at a final concentration range between 0.32 nM-10 uM (diluted in assay buffer) are added to the assay wells and allowed to incubate for 10 minutes prior to stimulation with PK1. After incubation with test compounds the assay plate is placed in a FLIPR Tetra (Molecular Devices) and PK1 (diluted in assay buffer) is added at the determined EC80 concentration (final). Ligand-dependent changes in intracellular calcium levels are determined by measuring changes in fluorescence of the dye at 525 nM following excitation at 485 nM. Readings from wells that do not contain antagonist enable percentage inhibition curves to be plotted using 4-parameter fit algorithm and IC50 values are calculated for each test compound.
- Ca-Flux Functional Assay GPR43 agonist/PAM activity was determined by measuring changes in intracellular calcium levels using a Ca2+ sensitive fluorescent dye. The changes in fluorescent signal were monitored by FLIPR (manufactured by Molecular Devices). GPR43 mediated increases in intracellular Ca2+ concentration were readily detected upon activation with sodium acetate. Prior to the assay (24 hours), CHO-K1 Gα16 cells stably expressing human GPR43 were-seeded in cell culture medium in black, clear-bottom 384-well plates (Corning Inc) and grown overnight at 37° C., 5% CO2. On the day of the assay, cell culture media was removed and cells were loaded with Calcium 5 Dye (Molecular Devices) diluted in HBSS containing 25 mM HEPES, 2.5 mM Probenecid, 0.1% BSA for 1 hour at 37° C., 5% CO2. 10 point half log concentration response curves of sodium acetate from 10 mM were conducted prior to the testing of compounds to calculate the sodium acetate concentration that produces 20% of the maximal response (EC20). Test compounds (at 10 point half log concentration response curves from 10 μM) were added in the presence of sodium acetate to achieve a final concentration that produces approximately 20% maximal response as calculated from the previous experiment. The changes in fluorescent signal were monitored by FLIPR upon addition of the compound/EC20 sodium acetate mix. The EC50 values were determined from ten point concentration response curves. Curves were generated using the average of two wells for each data point.
- Calcium Influx Assay Based on Fluorescence Ca2+ (calcium) influx assay is an experiment for measuring the activity of a positive allosteric modulator of mGluR5 receptor in which human mGluR5 receptor-overexpressed HEK293 cell line is used. The day before the experiment, cells were prepared in a cell culture medium (DMEM, 5% FBS) with the density of 80,000/well, and 100 μl of cells were dispensed into each well of a poly-D-lysine-coated 96-well plate. Cells were incubated in a 5% CO2, 37° C. incubator. The next day, the cell culture medium was removed from the plate, and 100 μl of 1× Fluo-4 calcium indicator diluted with a buffer (1× Hank's balanced salt solution, 20 mM HEPES, 2.5 mM probenecid) were added to each well and incubated at 37° C. for 1 hour. The compound stock solutions were prepared in 100% DMSO, and the compounds were serially diluted with a 1/4 dilution to 6 or 7 concentrations (final concentration was 10 μM to 10 nM). The diluted compound solutions were added to the plate with 0.1 to 0.2% of final DMSO concentration. 1 hour after the addition of Fluo-4 calcium indicator, L-glutamate (EC20 concentration) and the test compound solutions were added to the plate, and Ca2+ reaction was then measured by FLIPR at room temperature. The activity of the compounds was standardized on the basis of the results of maximum value-minimum value of fluorescent reaction, and the activity value was calculated on the basis that no activity on glutamate EC20 is 0% and the reaction to glutamate maximum value is 100%.
- Calcium Influx Assay Based on Fluorescence Ca2+ (calcium) influx assay is an experiment for measuring the activity of a positive allosteric modulator of mGluR5 receptor in which human mGluR5 receptor-overexpressed HEK293 cell line is used. The day before the experiment, cells were prepared in a cell culture medium (DMEM, 5% FBS) with the density of 80,000/well, and 100 μl of cells were dispensed into each well of a poly-D-lysine-coated 96-well plate. Cells were incubated in a 5% CO2, 37° C. incubator. The next day, the cell culture medium was removed from the plate, and 100 μl of 1× Fluo-4 calcium indicator diluted with a buffer (1× Hank's balanced salt solution, 20 mM HEPES, 2.5 mM probenecid) were added to each well and incubated at 37° C. for 1 hour. The compound stock solutions were prepared in 100% DMSO, and the compounds were serially diluted with a dilution to 6 or 7 concentrations (final concentration was 10 μM to 10 nM). The diluted compound solutions were added to the plate with 0.1 to 0.2% of final DMSO concentration. 1 hour after the addition of Fluo-4 calcium indicator, L-glutamate (EC20 concentration) and the test compound solutions were added to the plate, and Ca2+ reaction was then measured by FLIPR at room temperature. The activity of the compounds was standardized on the basis of the results of maximum value-minimum value of fluorescent reaction, and the activity value was calculated on the basis that no activity on glutamate EC20 is 0% and the reaction to glutamate maximum value is 100%.
- Evaluation of Activating Activity for OX1R and OX2R Human Embryonic Kidney cells 293 (HEK293) cells with forced expression of hOX1R or hOX2R were seeded in a 384-well microplate (Greiner) at 10,000 per well and cultured for 1 day in high-glucose-DMEM (FujiFilm Corp. Wako Pure Chemical Industries, Ltd.) containing added 10% FBS (Thermo Scientific) and 1% Penicillin-Streptomycin (FujiFilm Corp. Wako Pure Chemical Industries, Ltd.). After removing the medium, 30 μL of assay buffer (20 mM HEPES (Sigma-Aldrich Japan, KK.), Hank's balanced salt solution (Gibco), 0.1% BSA (Sigma-Aldrich Japan, KK.), 0.1% Pluronic F-127 (Invitrogen)) containing Calcium 4 dye (Molecular Device Corporation) and 2.5 mM probenecid (Sigma-Aldrich Japan, KK.) were added, and the mixture was incubated for 60 minutes. A 30 μL portion of assay buffer containing the test compound was added and reaction was initiated. Change in intracellular calcium ion concentration by the reaction was measured based on the fluorescence intensity ratio in terms of the fluorescence value with dual wavelength excitation at 480 nm and 540 nm, using FDSS7000 (Hamamatsu Photonics, K.K.). The test compound was dissolved in DMSO to 10 mM, and diluted with assay buffer to a final concentration of from 3×10−11 M to 1×10−5 M (DMSO final concentration of 0.1%). The EC50 value was determined from the fluorescence value with addition of the test compound at different concentrations, with the fluorescence value of the well with compound-free buffer added as 0%, and the fluorescence value of the well with 30 nM OX-A (Peptide Research Lab) as 100%.
- FLIPR Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents are from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μl M Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA.
- FLIPR Ca2+ Flux Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA.
- FLIPR Ca2+ Flux Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA.
- FLIPR Calcium Assay One day before the assay, CORNING black with clear flat bottom 96-well assay plates were coated with a 0.1 mg/mL Poly-L-Lysine solution. CHO-K1/MOR/Gα15 cells were suspended in the F12 medium and plated at a density of 8×104 cells/well in 200 μL medium. Cells were incubated in a humidified atmosphere of 10% CO2 at 37° C. overnight so as to reach an 80-90% confluent cell monolayer before assay. At the day of assay, 150 μL medium/well was removed from plate. To each well, 50 μL FLIPR calcium assay reagent dissolved in 1× assay buffer (HBSS: KCl 5 mM, KH2PO4 0.3 mM, NaCl 138 mM, NaHCO3 4 mM, Na2HPO4 0.3 mM, d-glucose 5.6 mM, with additional 20 mM HEPES and 13 mM CaCl2, pH 7.4), with 2.5 mM probenecid was added and the plate was incubated at 37° C. for 1 h. Compounds and other reagents were dissolved in the assay buffer. Using a FlexStationIII (Molecular Devices Corp.), the [Ca2+]i fluorescence increases after robotic injections of compounds or other reagents were monitored every 1.52 s interval with excitation wavelength at 485 nm and with emission wavelength at 525 nm. The [Ca2+]i fluorescence was measured up to 90 s after agonist injection. The fluorescence intensity from 6 to 12 wells of cells were averaged and the relative amount of [Ca2+]i release was determined by integrating the AUC of the [Ca2+]i fluorescence averages.
- Functional Calcium Assay CHO cells stably expressing human dopamine receptor type 2, long variant (hD2L), coupled to Gα16 protein (CHO-Gα16-hD2L) were seeded into black walled clear-base 384-well plates at a density of 8,000 cells per well and grown overnight at 37° C. After washing with the assay buffer (20 mM HEPES, 145 mM NaCl, 5 mM KCl, 5.5 mM glucose, 1 mM MgCl2 and 2 mM CaCl2, pH 7.4) containing 2.5 mM Probenecid, cells were incubated with the cytoplasmic Ca2+ probe Fluo-4 AM at 1 μM (final concentration), 37° C. for 60 min. Plates were washed three times as above and placed into a Fluorometric Imaging Plate Reader (FLIPR Tetra, Molecular Devices) to monitor cell fluorescence (ex=470-495 nm, em=515-575 nm) before and after the addition of different concentrations of test compounds. Compounds of invention were dissolved in DMSO and 200-fold diluted with assay buffer plus 0.01% Pluronic F-127. Cells were exposed first to test compounds for 10 min, then to a submaximal concentration of the hD2 receptor agonist dopamine (EC80, 50-140 nM). The fluorescence before compound addition (baseline) and before and after addition of agonist challenge was monitored. The peak of Ca2+ stimulation (baseline subtracted) was plotted versus the concentration of test compound and the curve fitted using a four-parameter logistic equation (XLfit) to assess the agonist/antagonist potency and maximal response.
- Functional Calcium Assay Functional Calcium Assay at hD2 recombinant receptor. CHO cells stably expressing human dopamine receptor type 2, long variant (hD2L), coupled to Gα16 protein (CHO-Gα16-hD2L) were seeded into black walled clear-base 384-well plates at a density of 8,000 cells per well and grown overnight at 37° C. After washing with the assay buffer (20 mM HEPES, 145 mM NaCl, 5 mM KCl, 5.5 mM glucose, 1 mM MgCl2 and 2 mM CaCl2, pH 7.4) containing 2.5 mM Probenecid, cells were incubated with the cytoplasmic Ca2+ probe Fluo-4 AM at 1 μM (final concentration), 37° C. for 60 min. Plates were washed three times as above and placed into a Fluorometric Imaging Plate Reader (FLIPR Tetra, Molecular Devices) to monitor cell fluorescence (ex=470-495 nm, em=515-575 nm) before and after the addition of different concentrations of test compounds. Compounds of invention were dissolved in DMSO and 200-fold diluted with assay buffer plus 0.01% Pluronic F-127. Cells were exposed first to test compounds for 10 min, then to a submaximal concentration of the hD2 receptor agonist dopamine (EC80, 50-140 nM). The fluorescence before compound addition (baseline) and before and after addition of agonist challenge was monitored. The peak of Ca2+ stimulation (baseline subtracted) was plotted versus the concentration of test compound and the curve fitted using a four-parameter logistic equation (XLfit) to assess the agonist/antagonist potency and maximal response.
- Functional Calcium Assay at hD2 Recombinant Receptor CHO cells stably expressing human dopamine receptor type 2, long variant (hD2L), coupled to Gα16 protein (CHO-Gα16-hD2L) were seeded into black walled clear-base 384-well plates at a density of 8,000 cells per well and grown overnight at 37° C. After washing with the assay buffer (20 mM HEPES, 145 mM NaCl, 5 mM KCl, 5.5 mM glucose, 1 mM MgCl2 and 2 mM CaCl2, pH 7.4) containing 2.5 mM Probenecid, cells were incubated with the cytoplasmic Ca2+ probe Fluo-4 AM at 1 μM (final concentration), 37° C. for 60 min. Plates were washed three times as above and placed into a Fluorometric Imaging Plate Reader (FLIPR Tetra, Molecular Devices) to monitor cell fluorescence (ex=470-495 nm, em=515-575 nm) before and after the addition of different concentrations of test compounds. Compounds of invention were dissolved in DMSO and 200-fold diluted with assay buffer plus 0.01% Pluronic F-127. Cells were exposed first to test compounds for 10 min, then to a submaximal concentration of the hD2 receptor agonist dopamine (EC80, 50-140 nM). The fluorescence before compound addition (baseline) and before and after addition of agonist challenge was monitored. The peak of Ca2+ stimulation (baseline subtracted) was plotted versus the concentration of test compound and the curve fitted using a four-parameter logistic equation (XLfit) to assess the agonist/antagonist potency and maximal response.
- Functional Calcium Assay at hD2 recombinant receptor CHO cells stably expressing human dopamine receptor type 2, long variant (hD2L), coupled to Gα16 protein (CHO-Gα16-hD2L) were seeded into black walled clear-base 384-well plates at a density of 8,000 cells per well and grown overnight at 37° C. After washing with the assay buffer (20 mM HEPES, 145 mM NaCl, 5 mM KCl, 5.5 mM glucose, 1 mM MgCl2 and 2 mM CaCl2, pH 7.4) containing 2.5 mM Probenecid, cells were incubated with the cytoplasmic Ca2+ probe Fluo-4 AM at 1 μM (final concentration), 37° C. for 60 min. Plates were washed three times as above and placed into a Fluorometric Imaging Plate Reader (FLIPR Tetra, Molecular Devices) to monitor cell fluorescence (ex=470-495 nm, em=515-575 nm) before and after the addition of different concentrations of test compounds. Compounds of invention were dissolved in DMSO and 200-fold diluted with assay buffer plus 0.01% Pluronic F-127. Cells were exposed first to test compounds for 10 min, then to a submaximal concentration of the hD2 receptor agonist dopamine (EC80, 50-140 nM). The fluorescence before compound addition (baseline) and before and after addition of agonist challenge was monitored. The peak of Ca2+ stimulation (baseline subtracted) was plotted versus the concentration of test compound and the curve fitted using a four-parameter logistic equation (XLfit) to assess the agonist/antagonist potency and maximal response.
- Heat-based Assay Briefly, hTRPV1/CHO cells were cultured in growth media in a tissue culture dish at 37° C. in a CO2 incubator. On the day of the assay, culture media were removed and the cells were then detached using 0.05% trypsin at 37° C. with 5% CO2, for 90 s. The detached cells were centrifuged (1000 rpm, 4 min) to remove trypsin-containing supernatant and resuspended in assay buffer (115 mM NaCl, 5.4 mM KCl, 0.8 mM MgCl2.6H2O, 1.8 mM CaCl2.2H2O, 13.8 mM D-glucose, and 20 mM HEPES). Then, the cells were loaded with 5 uM Fluo-4, a Ca2+ reporter dye, in the presence of 2.5 mM probenecid at 37° C. with 5% CO2, for 45 min. Thereafter, the cells were washed twice with measuring buffer (assay buffer supplemented with 0.1% BSA and 3.2 mM CaCl2) then transferred to a Fast 96-well Reaction Plate (0.1 mL) (Part no. 4346907, MICROAMP, Applied Biosystems, Foster City, Calif.). The cell density was 100,000 cells/24 uL/well. A solution of the compound under test (6 uL/well) was added into each well of the 96-well plate. Thus, the reaction volume per well was 30 uL. The plates were then placed inside an ABI7500 Fast Real-Time PCR instrument (Applied Biosystems) to read fluorescence at different temperatures using 7500 software, version 2.0.2 (Applied Biosystems). The initial temperature was set at 25° C. for 1 min. followed by a temperature ramp to 45° C. in 100 s to deliver heat to cells.
- In Vitro Assay: Intracellular Calcium Measurements In Vitro Assay: Intracellular Calcium Measurements:Chinese hamster ovary (CHO) cells expressing the human orexin-1 receptor and the human orexin-2 receptor, respectively, are grown in culture medium (Ham F-12 with L-Glutamine) containing 300 g/ml G418, 100 U/ml penicillin, 100 g/ml streptomycin and 10% heat inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into 384-well black clear bottom sterile plates (Greiner). The seeded plates are incubated overnight at 37° C. in 5% CO2. Human orexin-A as an agonist is prepared as 1 mM stock solution in MeOH:water (1:1), diluted in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/l and 20 mM HEPES for use in the assay at a final concentration of 3 nM.Antagonists are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates using DMSO followed by a transfer of the dilutions into in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/l and 20 mM HEPES. On the day of the assay, 50 μl of staining buffer (HBSS containing 1% FCS, 20 mM HEPES, NaHCO3: 0.375 g/l, 5 mM probenecid (Sigma) and 3 M of the fluorescent calcium indicator fluo-4 AM (1 mM stock solution in DMSO, containing 10% pluronic) is added to each well. The 384-well cell-plates are incubated for 50 min at 37° C. in 5% CO2 followed by equilibration at RT for 30 min before measurement.
- Inhibition Assay Chinese hamster ovary (CHO) cells expressing the human orexin-1 receptor and the human orexin-2 receptor, respectively, are grown in culture medium (Ham F-12 with L-Glutamine) containing 300 μg/ml G418, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into 384-well black clear bottom sterile plates (Greiner). The seeded plates are incubated overnight at 37° C. in 5% CO2.Human orexin-A as an agonist is prepared as 1 mM stock solution in MeOH: water (1:1), diluted in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/l and 20 mM HEPES for use in the assay at a final concentration of 3 nM.Antagonists are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates using DMSO followed by a transfer of the dilutions into in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/l and 20 mM HEPES. On the day of the assay, 50 μl of staining buffer (HBSS containing 1% FCS, 20 mM HEPES, NaHCO3: 0.375 g/l, 5 mM probenecid (Sigma) and 3 M of the fluorescent calcium indicator fluo-4 AM (1 mM stock solution in DMSO, containing 10% pluronic) is added to each well. The 384-well cell-plates are incubated for 50 min at 37° C. in 5% CO2 followed by equilibration at RT for 30 min before measurement.
- Inhibitory Activity Assay The method described hereafter is used for determining the inhibitory activity of the present compounds on hERG1. Materials and Instruments(1) FluxOR potassium ion channel assay (F10016, invitrogen)(2) FlexStation3 microplate reader (molecular devices)(3) hERG/HEK293 cell: HEK293 cell line stably expressing the hERG channel transfected by hERG cDNA (NCBI SEQ ID NO. NM-000238(RC215928, origene)).2. Experimental ProcedureExcept for ddH2O, all of the experimental reagents are from FluxOR Potassium Ion Channel Assay Kit and the formulation methods also refer to the kit instructions.(1) Human hERG/HEK293 cell was seeded on PDL (Poly-D-lysine) coated plates at 25000 cells/well on the previous day;(2) After overnight culture, the plate medium was discarded; then according to FluxOR potassium ion channel detection requirements operation, the dye was added at 100 μL/hole, and then incubated for 90 mins at room temperature;(3) The dye was then decanted and 100 μL of assay buffer containing 1004, probenecid were added in each well;(4) 1 μL of compound or DMSO was added to the corresponding wells, shocked for 30 seconds, and incubated for 30 mins at room temperature;(5) The plates were placed in a FlexStation3 microplate reader, and then added with stimulation buffer (K2SO4: Tl2SO4: 1×FluxOR Chloride-free Buffer: ddH2O=2:1:2:5) at 25 μL/well, then the value was read continuously for 5 mins at EX/EM of 490/525 nm immediately; and(6) The IC50 of the present compounds on human hERG ion channel was obtained by data processing software Graphpad.
- Evaluation of Activity for OX1R and OX2R HEK293 (human embryonic kidney 293) cells with forced expression of human OX1R (hOX1R) or human OX2R (hOX2R) were seeded in a 384-well microplate (Greiner) at 10,000 per well and cultured for 1 day in high-glucose-DMEM (FujiFilm Corp. Wako Pure Chemical Industries, Ltd.) containing added 10% FBS (Tenno Scientific) and 1% Penicillin-Streptomycin (FujiFilm Corp. Wako Pure Chemical Industries, Ltd.). After removing the medium, 40 μL of assay buffer (20 mM HEPES (Sigma-Aldrich Japan, KK.), Hanks' balanced salt solution (Gibco), 0.1% BSA (Sigma-Aldrich Japan, KK.), 0.1% Pluronic F-127 (Invitrogen)) containing Calcium 4 dye (Molecular Device Corporation) and 2.5 mM probenecid (Sigma-Aldrich Japan, KK.) were added, and the plate was incubated for 60 minutes. After further adding 20 μL of assay buffer, 20 μL of assay buffer containing the test compound was added and reaction was initiated. Change in intracellular calcium ion concentration during the reaction was measured based on the fluorescence intensity ratio in terms of the fluorescence value with wavelength excitation at 480 nm and detection at 540 nm, using FDSS7000 (Hamamatsu Photonics, K.K.). The test compound was dissolved in DMSO to 10 mM, and diluted with assay buffer to a final concentration of from 3×10−11 M to 1×10−7 M (DMSO final concentration of 0.1%). The half maximal effective concentration (EC50 value) was determined from the fluorescence value with addition of the test compound at different concentrations, with the fluorescence value of the well with compound-free buffer added as 0%, and the fluorescence value of the well with 10 nM OX-A (Peptide Research Lab) as 100%.
- FLIPR Ca2+ Flux Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well.
- Inhibition Assay Test Example 3: (1) The TRPV4 inhibitory activity was measured using CHO-K1 cells stably expressing human TRPV4 (hTRPV4/CHO cells). (2) Frozen cells were thawed and subcultured with the medium (MEM-α, 10% FBS, 200 mmol/L Glutamine, 50 unit/mL penicillin, 50 μg/mL streptomycin, 1 mg/mL G418). (3) The 96-well plates which hTRPV4/CHO cells were seeded at densities of 2×10^4 cells/well in the culture medium and cultured in a CO2 incubator in the presence of 5% CO2 at 37° C. for 24 h was used as assay plates. (4) The assay plate was washed with assay buffer (Hanks, 1 mol/L HEPES, 250 mmol/L probenecid, pH7.4). (5) Fluo-3, fluorescent dye for Ca influx assay was added to each well, then the assay plate was incubated in a CO2 incubator in the presence of 5% CO2 at 37° C. for one hour (final conc.; 5 μmmol/L Fluo-3). (6) The assay plate was washed with the assay buffer, and the buffer was remained at 30 μL/well. Then the assay plate was incubated for 10 min at 37° C. (7) Diluted compound solution was dispensed to each well in the compound plate, and mixed with built-in Pipette and Mixer of the fluorescence analysis system FDSS 3000 (Hamamatsu Photonics). (8) 50 μL of 4α-PDD solution (concluding 0.1% Pluronic F-127) was applied to each well of assay plate and mixed. (9) The fluorescent intensity was measured by FDSS 3000 for 8 min from the point of time addition the compound solution, at Ex 480 nm, Em 540 nm wavelength.
- Inhibitory Activity Assay human ROMK and rat ROMK: 1. Materials and Instruments (1) FluxOR potassium ion channel assay (F10016, Invitrogen) (2) Ouabain (03125-1G, Sigma) (3) FlexStation3 microplate reader (Molecular Devices) (4) Human ROMK/HEK293 cell: HEK293 cell line stably expressing the ROMK channel transfected by human ROMK cDNA (NCBI SEQ ID NO. NM-000220.4) (5) Rat ROMK/HEK293 cell: HEK293 cell line transfected by rat ROMK cDNA (NCBI SEQ ID NO. NM-017023.1) stably expressing the ROMK channel (6) HEK293 cell line: Cell Bank of Chinese Academy of Sciences, GNHu43 2. Experimental Procedure - Human ROMK/HEK293 cell was seeded on PDL(Poly-D-lysine) coated plates at 20000 cells/well on the previous day; After overnight culture, the plate medium was discarded; then according to the Fluxor Potassium Ion Channel Assay Kit instructions, the dye was added at 100 μL/hole, and then incubated for 90 mins at room temperature; The dye was then decanted and 100 μL of assay buffer containing ouabain (300 μM) and probenecid were added in each well;1 μL of compound or DMSO was added to the corresponding wells, shocked for 30 seconds, and incubated for 30 mins at room temperature; The plates were placed in a FlexStation3 microplate reader, and then added with stimulation buffer (K2SO4:Tl2SO4:1XFluxOR Chloride-free Buffer:ddH2O=3:12:40:125) at 25 μL/well, then the value was read continuously for 5 mins at EX/EM of 490/525 nm immediately; and The IC50 of the present compounds on human ROMK channel was obtained by data processing software Graphpad.
- PAR-1 FLIPR Assay Frozen HEK 293 Cells were plated in 384-well PDL coated plates at 12000 cells/well in 50 uL of DMEM media containing 10% FBS, pen/strep/L-Glutamine and non-essential amino acids, incubated overnight at 37° C./5% CO2. Media was then removed from the cells, incubated with 33 uL of Calcium-5 dye in assay buffer (Hank's buffer containing 20 mM HEPES, 0.04% Chaps and 2.5 mM Probenecid) for 60 minutes at 37° C. 2 uL of varying concentrations of compound in 40% DMSO in assay buffer (final DMSO concentration is 2.3%) were then added to the cells and incubated at 25° C. for 30 minutes. The plates were added to the FLIPR Tetra , the device added 5 μL of PAR-1 selective receptor-activating peptide (sequence Ala-parafluoroPhe-Arg-Cha-Cit-Try-NH2, prepared in water) at a concentration equal to the effective concentration that achieved 80% activation of signaling on the day of the experiment. The range of peptide was from 1.5-3 μM. The final volume is 40 uL/well, with 2% DMSO. The FLIPR was read at an excitation wavelength of 480 nm and an emission wavelength of 535 nm, and performed 60 scans over a 1-2 min reading time. The data were analyzed by taking the peak signal over a portion of the range of the 60 scans and dividing this signal by the minimum signal for that same range. The data were expressed as percent inhibition of the maximum divided by the minimum signal achieved at 80% activation produced by the PAR1 activating peptide on the test day. The compounds of Examples 1-13 were tested in the assay described above and the data collected for these compounds is provided.
- PAR-1 FLIPR Assay This assay measures the potency of the inventive compounds as PAR-1 receptor antagonists.Frozen HEK 293 Cells were plated in 384-well PDL coated plates at 12000 cells/well in 50 uL of DMEM media containing 10% FBS, pen/strep/L-Glutamine and non-essential amino acids, incubated overnight at 37° C./5% CO2. Media was then removed from the cells, incubated with 33 ul of Calcium-5 dye in assay buffer (Hank's buffer containing 20 mM HEPES, 0.04% Chaps and 2.5 mM Probenecid) for 60 minutes at 37° C. 2 uL of varying concentrations of compound in 40% DMSO in assay buffer (final DMSO concentration is 2.3%) were then added to the cells and incubated at 25° C. for 30 minutes. The plates were added to the FLIPR Tetra, the device added 5 uL of PAR-1 selective receptor-activating peptide (sequence Ala-parafluoroPhe-Arg-Cha-Cit-Try-NH2, prepared in water) at a concentration equal to the effective concentration that achieved 80% activation of signaling on the day of the experiment. The range of peptide was from 1.5-3 μM. The final volume was 40 uL/well, with 2% DMSO. The FLIPR was read at an excitation wavelength of 480 nm and an emission wavelength of 535 nm, and performed 60 scans over a 1-2 min reading time. The data were analyzed by taking the peak signal over a portion of the range of the 60 scans and dividing this signal by the minimum signal for that same range. The data were expressed as percent inhibition of the maximum divided by the minimum signal achieved at 80% activation produced by the PAR-1 activating peptide on the test day. The compounds of Examples 1-21 were tested in the assay described above and the data collected for these compounds is provided.
- In Vitro Test of Inhibition of Human FP Receptor Activity For the characterization of test substances in respect of FP antagonism, PGF2α-induced calcium flux in FP-expressing CHEM1 cells (Millipore, HTS093C) was used.3000 cells in 30 μl of full medium [DMEM F12, 10% FCS, 1.35 mM sodium pyruvate, 20 mM HEPES, 4 mM GlutaMAX , 2% sodium bicarbonate, 1% Pen/Strep, 1% 100× non-essential amino acids] are sown per well of a 384 multititre plate (from Greiner, TC plate, black with clear base) and incubated at 33° C., 5% CO2 for 24 hours. Prior to the measurement, the medium is replaced by 30 μl of Fluo-8 AM loading buffer [calcium-free Tyrode (130 mM NaCl, 5 mM KCl, 20 mM HEPES, 1 mM MgCl2, 4.8 mM NaHCO3, pH 7.4), 2 mM CaCl2, 6.3 mM Probenecid, 5 PM Fluo-8 AM, 0.0112% Pluronic] and incubated at 37° C., 5% CO2 for 30 minutes. The test substance is prepared in DMSO in various concentrations as a dose-response curve (starting concentration 10 mM, dilution factor 3.16) and prediluted 1:50 with calcium-free Tyrode, 2 mM CaCl2, 0.002% SmartBlock (from CANDOR Bioscience GmbH). 10 μl of the prediluted substance solution are added to the Fluo-8-laden cells and incubated at 37° C., 5% CO2 for 10 minutes. The FP receptor is activated by adding 40 μl of 2 nM (final concentration) PGF2α in calcium-free Tyrode, 2 mM CaCl2, 0.002% SmartBlock, and the calcium flux is determined by measuring the fluorescence at ex. 470 nm/em. 525 nm in a fluorescence measuring instrument (FLIPR Tetra, Molecular Devices) for 120 seconds.
- Evaluation of In Vitro Biological Activity The antagonist property of the compounds disclosed herein was determined using the FLIPR (fluorescence imaging plate reader) method, showing that the compounds are inhibitors for the intracellular calcium increase induced by the activation of hP2X3 (human purinergic P2X receptor subtype 3, Accession No. NM_002559.4) expressed in HEK293 cells (human renal epithelial cell line, ATCC). HEK293 cells that stably express hP2X3 were cultured in DMEM high glucose medium containing 10% FBS (fetal bovine serum, Gibco, 10099-141), 1% penicillin-streptomycin (Gibco, 15140-122) and 1 mg/mL G418 (Invitrogen, 10131027) in a cell incubator at 37 C., 5% humidity. Cells at 400,000 cells/mL were seeded into a 384-well plate (10,000 cells/well) 18-24 h prior to the FLIPR experiment and then incubated overnight in a cell incubator. On the day of the experiment, the medium was discarded and the cells were washed in an FLIPR buffer (each 30 mL buffer contains 0.3 mL of probenecid (Thermo, P36400), 0.6 mL of 1 M HEPES (Invitrogen, 15630080) and 29.1 mL of HBSS (Invitrogen, 14065056)). Each well was added with 20 μL of 0.5 Calcium 6 fluorescent dye (Molecular Devices, R8190) and then was subjected to dye-loading incubation at 37 C. for 1.5 h. Each well was added with 10 μL of test compound (which was dissolved in DMSO at a concentration of 10 mM and serially diluted with buffer) or vehicle, and then was left to equilibrate for 30 min at room temperature. The cell plate was then placed in the FLIPR for baseline fluorescence measurements (excitation at 485 nm and emission at 525-535 nm). An agonist (BZ-ATP (Sigma, B6396) at a final concentration of 2.5 μM) or a vehicle (ultrapure water) was then added at 10 μL/well, fluorescence values were measured for 2 min at 1-second intervals, and finally the output fluorescence counts were analyzed.
- FLIPR Ca2+ Flux Assay For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added.
- In Vitro Assay Human orexin-A as an agonist is prepared as 1 mM stock solution in MeOH: water (1:1), diluted in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/L and 20 mM HEPES for use in the assay at a final concentration of 3 nM.Antagonists are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates using DMSO followed by a transfer of the dilutions into in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/L and 20 mM HEPES. On the day of the assay, 50 uL of staining buffer (HBSS containing 1% FCS, 20 mM HEPES, NaHCO3: 0.375 g/L, 5 mM probenecid (Sigma) and 3 uM of the fluorescent calcium indicator fluo-4 AM (1 mM stock solution in DMSO, containing 10% pluronic) is added to each well. The 384-well cell-plates are incubated for 50 min at 37° C. in 5% CO2 followed by equilibration at rt for 30 min before measurement.Within the Fluorescent Imaging Plate Reader (FLIPR Tetra, Molecular Devices), antagonists are added to the plate in a volume of 10 uL/well, incubated for 120 min and finally 10 uL/well of agonist is added. Fluorescence is measured for each well at 1 second intervals, and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 3 nM orexin-A with vehicle in place of antagonist. The IC50 value (the concentration of compound needed to inhibit 50% of the agonistic response) is determined and may be normalized using the obtained IC50 value of an on-plate reference compound. Optimized conditions were achieved by adjustment of pipetting speed and cell splitting regime. The calculated IC50 values may fluctuate depending on the daily cellular assay performance. Fluctuations of this kind are known to those skilled in the art. In the case where IC50 values have been determined several times for the same compound, the geometric mean has been given.
- In Vitro Test of Inhibition of Human FP Receptor Activity For the characterization of test substances in respect of FP antagonism, PGF2α-induced calcium flux in FP-expressing CHEM1 cells (Millipore, HTS093C) was used.3000 cells in 25 μl of full medium [DMEM F12, 10% FCS, 1.35 mM sodium pyruvate, 20 mM HEPES, 4 mM GlutaMAX, 2% sodium bicarbonate, 1% Pen/Strep, 1% 100× non-essential amino acids] are sown per well of a 384 multititer plate (from Greiner, TC plate, black with clear base) and incubated at 37° C./5% CO2 for 24 hours. Prior to the measurement, the medium is replaced by 30 μl of Fluo-8 AM loading buffer [calcium-free Tyrode (130 mM NaCl, 5 mM KCl, 20 mM HEPES, 1 mM MgCl2, 4.8 mM NaHCO3, pH 7.4), 2 mM CaCl2, 1× SmartBlock (from CANDOR Bioscience GmbH), 4.5 mM Probenecid, 5 μM Fluo-8 AM, 0.016% Pluronic, 0.04% Brilliant black] and incubated at 37° C./5% CO2 for 30 minutes. The test substance is prepared in DMSO in various concentrations as a dose-response curve (starting concentration 10 mM, dilution factor 3.16) and prediluted 1:50 with calcium-free Tyrode/2 mM CaCl2. 10 μl of the prediluted substance solution are added to the Fluo-8-laden cells and incubated at 37° C./5% CO2 for 10 minutes. The FP receptor is activated by adding 20 μl of 3 nM (final concentration) PGF2α in calcium-free Tyrode/2 mM CaCl2/0.04% Brilliant black, and the calcium flux is determined by measuring the fluorescence at ex. 470 nm/em. 525 nm in a fluorescence measuring instrument (FLIPR Tetra, Molecular Devices) for 120 seconds.
- In Vitro Test of Inhibition of Human FP Receptor Activity (B-1A) For the characterization of test substances in respect of FP antagonism, PGF2α-induced calcium flux in FP-expressing CHEM1 cells (Millipore, HTS093C) was used.3000 cells in 25 μl of full medium [DMEM F12, 10% FCS, 1.35 mM sodium pyruvate, 20 mM HEPES, 4 mM GlutaMAX, 2% sodium bicarbonate, 1% Pen/Strep, 1% 100× non-essential amino acids] are sown per well of a 384 multititer plate (from Greiner, TC plate, black with clear base) and incubated at 37° C./5% CO2 for 24 hours. Prior to the measurement, the medium is replaced by 30 μl of Fluo-8 AM loading buffer [calcium-free Tyrode (130 mM NaCl, 5 mM KCl, 20 mM HEPES, 1 mM MgCl2, 4.8 mM NaHCO3, pH 7.4), 2 mM CaCl2, 1× SmartBlock (from CANDOR Bioscience GmbH), 4.5 mM Probenecid, 5 μM Fluo-8 AM, 0.016% Pluronic, 0.04% Brilliant black] and incubated at 37° C./5% CO2 for 30 minutes. The test substance is prepared in DMSO in various concentrations as a dose-response curve (starting concentration 10 mM, dilution factor 3.16) and prediluted 1:50 with calcium-free Tyrode/2 mM CaCl2. 10 μl of the prediluted substance solution are added to the Fluo-8-laden cells and incubated at 37° C./5% CO2 for 10 minutes. The FP receptor is activated by adding 20 μl of 3 nM (final concentration) PGF2α in calcium-free Tyrode/2 mM CaCl2/0.04% Brilliant black, and the calcium flux is determined by measuring the fluorescence at ex. 470 nm/em. 525 nm in a fluorescence measuring instrument (FLIPR Tetra, Molecular Devices) for 120 seconds.
- In Vitro Test of Inhibition of Human FP Receptor Activity For the characterization of test substances in respect of FP antagonism, PGF2α-induced calcium flux in FP-expressing CHEM1 cells (Millipore, HTS093C) was used.3000 cells in 30 μl of full medium [DMEM F12, 10% FCS, 1.35 mM sodium pyruvate, 20 mM HEPES, 4 mM GlutaMAX , 2% sodium bicarbonate, 1% Pen/Strep, 1% 100× non-essential amino acids] are sown per well of a 384 multititre plate (from Greiner, TC plate, black with clear base) and incubated at 33° C., 5% CO2 for 24 hours. Prior to the measurement, the medium is replaced by 30 μl of Fluo-8 AM loading buffer [calcium-free Tyrode (130 mM NaCl, 5 mM KCl, 20 mM HEPES, 1 mM MgCl2, 4.8 mM NaHCO3, pH 7.4), 2 mM CaCl2, 6.3 mM Probenecid, 5 μM Fluo-8 AM, 0.0112% Pluronic ] and incubated at 37° C., 5% CO2 for 30 minutes. The test substance is prepared in DMSO in various concentrations as a dose-response curve (starting concentration 10 mM, dilution factor 3.16) and prediluted 1:50 with calcium-free Tyrode, 2 mM CaCl2, 0.002% SmartBlock (from CANDOR Bioscience GmbH). 10 μl of the prediluted substance solution are added to the Fluo-8-laden cells and incubated at 37° C., 5% CO2 for 10 minutes. The FP receptor is activated by adding 40 μl of 2 nM (final concentration) PGF2α in calcium-free Tyrode, 2 mM CaCl2, 0.002% SmartBlock, and the calcium flux is determined by measuring the fluorescence at ex. 470 nm/em. 525 nm in a fluorescence measuring instrument (FLIPR Tetra , Molecular Devices) for 120 seconds.
- Biological Assay The Inhibitory Activity of the Present Compounds on Human ROMK and Rat ROMK ChannelsThe method described hereafter was used for determining the inhibitory activity of the present compounds on human ROMK and rat ROMK channels.1. Materials and Instruments(1) FluxOR potassium ion channel assay (F10016, Invitrogen)(2) Ouabain (O3125-1G, Sigma)(3) FlexStation3 microplate reader (Molecular Devices)(4) Human ROMK/HEK293 cell: HEK293 cell line stably expressing the ROMK channel transfected by human ROMK cDNA (NCBI SEQ ID NO. NM-000220.4)(5) Rat ROMK/HEK293 cell: HEK293 cell line transfected by rat ROMK cDNA (NCBI SEQ ID NO. NM-017023.1) stably expressing the ROMK channel(6) HEK293 cell line: Cell Bank of Chinese Academy of Sciences, GNHu432. Experimental ProcedureExcept for ddH2O and Ouabain, all of the experimental reagents are from FluxOR Potassium Ion Channel Assay Kit and the formulation methods also refer to the kit instructions. (1) Human ROMK/HEK293 cell was seeded on PDL (Poly-D-lysine) coated plates at 20000 cells/well on the previous day; (2) After overnight culture, the plate medium was discarded; then according to the Fluxor Potassium Ion Channel Assay Kit instructions, the dye was added at 100 μL/hole, and then incubated for 90 mins at room temperature; (3) The dye was then decanted and 1004, of assay buffer containing ouabain (30004) and probenecid were added in each well; (4) 1 μL of compound or DMSO was added to the corresponding wells, shocked for 30 seconds, and incubated for 30 mins at room temperature; (5) The plates were placed in a FlexStation3 microplate reader, and then added with stimulation buffer (K2SO4: Tl2SO4: 1×FluxOR Chloride-free Buffer: ddH2O=3:12:40:125) at 25 μL/well, then the value was read continuously for 5 mins at EX/EM of 490/525 nm immediately; and (6) The IC50 of the present compounds on human ROMK channel was obtained by data processing software Graphpad.
- FLIPR Ca2+ Flux Assay All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist. For each antagonist, IC50 value (the concentration of compound needed to inhibit 50% of the agonist response) is determined. Alternatively, compound potency can be assessed by a radioligand binding assay (described in Bergman et. al. Bioorg. Med. Chem. Lett. 2008, 18, 1425-1430) in which the inhibition constant (Ki) is determined in membranes prepared from CHO cells expressing either the OX1 or OX2 receptor. The intrinsic orexin receptor antagonist activity of a compound which may be used in the present invention may be determined by these assays.
- FLIPR Ca2+ Flux Assay Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 ug/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 ul assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 ul assay buffer containing 1 uM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 ul assay buffer. 30 ul of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 ul, incubated for 5 min and finally 25 ul of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist.
- FLIPR Ca2+ Flux Assay For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist.
- FLIPR Ca2+ Flux Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added.
- In Vitro Assay Chinese hamster ovary (CHO) cells expressing the human orexin-1 receptor and the human orexin-2 receptor, respectively, are grown in culture medium (Ham F-12 with L-Glutamine) containing 300 μg/mL G418, 100 U/mL penicillin, 100 μg/mL streptomycin and 10% heat inactivated fetal calf serum (FCS). The cells are seeded at 20'000 cells/well into 384-well black clear bottom sterile plates (Greiner). The seeded plates are incubated overnight at 37 °C. in 5% CO2. Human orexin-A as an agonist is prepared as 1 mM stock solution in MeOH:water (1:1), diluted in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/l and 20 mM HEPES for use in the assay at a final concentration of 3 nM. Antagonists are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates using DMSO followed by a transfer of the dilutions into in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/l and 20 mM HEPES. On the day of the assay, 50 μl of staining buffer (HBSS containing 1% FCS, 20 mM HEPES, NaHCO3: 0.375 g/l, 5 mM probenecid (Sigma) and 3 μM of the fluorescent calcium indicator fluo-4 AM (1 mM stock solution in DMSO, containing 10% pluronic) is added to each well. The 384-well cell-plates are incubated for 50 min at 37 °C. in 5% CO2 followed by equilibration at RT for 30 min before measurement. Within the Fluorescent Imaging Plate Reader (FLIPR Tetra, Molecular Devices), antagonists are added to the plate in a volume of 10 μl/well, incubated for 10 min and finally 10 μl/well of agonist is added. Fluorescence is measured for each well at 1 second intervals, and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 3 nM orexin-A with vehicle in place of antagonist.
- In Vitro Assay Chinese hamster ovary (CHO) cells expressing the human orexin-1 receptor and the human orexin-2 receptor, respectively, are grown in culture medium (Ham F-12 with L-Glutamine) containing 300 μg/mL G418, 100 U/mL penicillin, 100 μg/mL streptomycin and 10% heat inactivated fetal calf serum (FCS). The cells are seeded at 20'000 cells/well into 384-well black clear bottom sterile plates (Greiner). The seeded plates are incubated overnight at 37 °C. in 5% CO2. Human orexin-A as an agonist is prepared as 1 mM stock solution in MeOH:water (1:1), diluted in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/l and 20 mM HEPES for use in the assay at a final concentration of 3 nM. Antagonists are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates using DMSO followed by a transfer of the dilutions into in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/l and 20 mM HEPES. On the day of the assay, 50 μl of staining buffer (HBSS containing 1% FCS, 20 mM HEPES, NaHCO3: 0.375 g/l, 5 mM probenecid (Sigma) and 3 μM of the fluorescent calcium indicator fluo-4 AM (1 mM stock solution in DMSO, containing 10% pluronic) is added to each well. The 384-well cell-plates are incubated for 50 min at 37 °C. in 5% CO2 followed by equilibration at RT for 30 min before measurement. Within the Fluorescent Imaging Plate Reader (FLIPR Tetra, Molecular Devices), antagonists are added to the plate in a volume of 10 μl/well, incubated for 120 min and finally 10 μl/well of agonist is added. Fluorescence is measured for each well at 1 second intervals, and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 3 nM orexin-A with vehicle in place of antagonist.
- Inhibition Assay Test Example 1: (1) The TRPV4 inhibitory activity was measured using CHO-K1 cells stably expressing human TRPV4 (hTRPV4/CHO cells). (2) In the day before the experimental day, frozen cell were thawed and washed with the culture medium (MEM-α, 10% FBS, 2 mmol/L GlutaMax, 50 unit Penicillin, 50 μg/mL Streptomycin). Then cells were suspended in the culture medium. (3) The 384-well plates which hTRPV4/CHO cells were seeded at densities of 4000 cells/well in the culture medium and cultured in a CO2 incubator in the presence of 5% CO2 at 37° C. for overnight was used as assay plates. (4) The assay plate was washed with assay buffer (Hanks, 20 mmol/L HEPES, 2.5 mmol/L probenecid, pH7.4), and the buffer were remained at 20 μL/well. (5) 10 μl of dye loading buffer (9 μmol/L Fluo 4-AM, 0.09% Pluronic F-127/assay buffer) was added to each well, then the assay plate was incubated in a CO2 incubator in the presence of 5% CO2 at 37° C. for one hour. (final 3 μmol/L Fluo4-AM). (6) The assay plate was washed with the assay buffer, and the buffers were remained at 20 μL/well. Then the assay plate was incubated for 10 min at room temperature. (7) Diluted compound solution was dispensed to each well in the compound plate, and mixed with built-in Pipette and Mixer of the Fluorescence analysis system FLIPR TETRA (Molecular devices). (8) After incubation for 5 min, 20 μL of 4α-PDD solution were applied to each well of assay plate and mixed with the FLIPR TETRA. (final 1 mol/L 4α-PDD). (9) The fluorescent intensity was measured with FLIPR TETRA system for 10 min from the point of time addition the compound solution, at Ex 470-495 nm, Em 515-575 nm wavelength.
- Inhibition Assay Test Example 2: (1) The TRPV4 inhibitory activity was measured using CHO-K1 cells stably expressing human TRPV4 (hTRPV4/CHO cells). (2) In the day before the experimental day, frozen cell were thawed and washed with the culture medium (MEM-α, 10% FBS, 4 mmol/L L-Glutamine, 50 unit Penicillin, 50 μg/mL Streptomycin). Then cells were suspended in the culture medium. (3) The 384-well plates which hTRPV4/CHO cells were seeded at densities of 4000 cells/well in the culture medium and cultured in a CO2 incubator in the presence of 5% CO2 at 37° C. for overnight was used as assay plates. (4) The assay plate was washed with assay buffer (Hanks, 20 mmol/L HEPES, 2.5 mmol/L probenecid, pH7.4), and the buffer were remained at 20 μL/well. (5) 10 μl of dye loading buffer (9 μmol/L Fluo 3-AM, 0.09% Pluronic F-127, 1% BSA/assay buffer), was added to each well, then the assay plate was incubated in a CO2 incubator in the presence of 5% CO2 at 37° C. for one hour. (final 3 μmol/L Fluo3-AM). (6) The assay plate was washed with the assay buffer, and the buffers were remained at 20 μL/well. Then the assay plate was incubated for 10 min at room temperature. (7) Diluted compound solution was dispensed to each well in the compound plate, and mixed with built-in Pipette and Mixer of the Fluorescence analysis system FLIPR 384 (Molecular devices). (8) After incubation for 4 min, 25 μL of 4α-PDD solution were applied to each well of assay plate and mixed with the FLIPR TETRA. (final 600 nmol/L 4α-PDD). (9) The fluorescent intensity was measured with FLIPR TETRA system for 7 min from the point of time addition the compound solution, at Ex 488 nm, Em 510-570 nm wavelength.
- Intracellular Calcium Assay Chinese hamster ovary (CHO) cells expressing the human orexin-1 receptor and the human orexin-2 receptor, respectively, are grown in culture medium (Ham F-12 with L-Glutamine) containing 300 μg/mL G418, 100 U/mL penicillin, 100 μg/mL streptomycin and 10% heat inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into 384-well black clear bottom sterile plates (Greiner). The seeded plates are incubated overnight at 37° C. in 5% CO2. Human orexin-A as an agonist is prepared as 1 mM stock solution in MeOH:water (1:1), diluted in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/L and 20 mM HEPES for use in the assay at a final concentration of 3 nM. Antagonists are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates using DMSO followed by a transfer of the dilutions into in HBSS containing 0.1% bovine serum albumin (BSA), NaHCO3: 0.375 g/L and 20 mM HEPES. On the day of the assay, 50 μL of staining buffer (HBSS containing 1% FCS, 20 mM HEPES, NaHCO3: 0.375 g/L, 5 mM probenecid (Sigma) and 3 μM of the fluorescent calcium indicator fluo-4 AM (1 mM stock solution in DMSO, containing 10% pluronic) is added to each well. The 384-well cell-plates are incubated for 50 min at 37° C. in 5% CO2 followed by equilibration at rt for 30 min before measurement. Within the Fluorescent Imaging Plate Reader (FLIPR Tetra, Molecular Devices), antagonists are added to the plate in a volume of 10 μL/well, incubated for 120 min and finally 10 μL/well of agonist is added. Fluorescence is measured for each well at 1 second intervals, and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 3 nM orexin-A with vehicle in place of antagonist.
- FLIPR Ca2+ Flux Assay . In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist.
- FLIPR Ca2+ Flux Assay Briefly, for intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the orexin-1 receptor (e.g., rat or human) or the orexin-2 receptor (e.g., rat or human), are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at approximately 20,000 cells per well into 384-well clear bottom sterile plates coated with poly-D-lysine. The seeded plates are incubated overnight at 37° C. and 5% CO2. Human ala-6,12 orexin-A can be used as the agonist and prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then in assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 minutes (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4 AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 minutes, and then 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes, and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM of agonist ala-6,12 orexin-A with buffer in place of test compound.
- FLIPR Ca2+ Flux Assay FLIPR Ca2+ Flux Assay- (Okumura et al., Biochem. Biophys. Res. Comm. 280:976-981, 2001). In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° CO2. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added.
- FLIPR Ca2+ Flux Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist.
- FLIPR Ca2+ Flux Assay TBDIn a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 g/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist.
- FLIPR Ca2+ Flux Assay n a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents are from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist.
- Heat-Based Assay CHO cells stably expressing human TRPV1 (hTRPV1) were used. Functional assessment of heat-induced activation of hTRPV1 was carried out in a cell-based Ca2+ flux assay using ABI7500 Fast Real-Time PCR System as described in Reubish et al., "Functional assessment of temperature-gated ion-channel activity using a real-time PCR machine," www.BioTechniques.com 47(3):iii-ix (2009), which is hereby incorporated by reference. Briefly, hTRPV1/CHO cells were cultured in growth media in a tissue culture dish at 37° C. in a CO2 incubator. On the day of the assay, culture media were removed and the cells were then detached using 0.05% trypsin at 37° C. with 5% CO2, for 90 s. The detached cells were centrifuged (1000 rpm, 4 min) to remove trypsin-containing supernatant and resuspended in assay buffer (115 mM NaCl, 5.4 mM KCl, 0.8 mM MgCl2.6H2O, 1.8 mM CaCl2.2H2O, 13.8 mM D-glucose, and 20 mM HEPES). Then, the cells were loaded with 5 μM Fluo-4, a Ca2+ reporter dye, in the presence of 2.5 mM probenecid at 37° C. with 5% CO2, for 45 min. Thereafter, the cells were washed twice with measuring buffer (assay buffer supplemented with 0.1% BSA and 3.2 mM CaCl2) then transferred to a Fast 96-well Reaction Plate (0.1 mL) (Part no. 4346907, MICROAMP, Applied Biosystems, Foster City, Calif.). The cell density was 100,000 cells/24 μL/well. A solution of the compound under test (6 μL/well) was added into each well of the 96-well plate. Thus, the reaction volume per well was 30 μL. The plates were then placed inside an ABI7500 Fast Real-Time PCR instrument (Applied Biosystems) to read fluorescence at different temperatures using 7500 software, version 2.0.2 (Applied Biosystems). The initial temperature was set at 25° C. for 1 min. followed by a temperature ramp to 45° C. in 100 s to deliver heat to cells.
- In Vitro LPA1 Receptor Assay Engagement of the LPA1 receptor by its ligand, oleoyl-L-α-lysophosphatidic acid (LPA), leads to the release of intracellular stores of calcium into the cytoplasm mediated through a Gq-driven increase in inositol triphosphate (IP3) levels. Gq is a heterotrimeric G protein subunit that activates phospholipase C.The ability of test compounds to prevent LPA-driven intracellular release of stored calcium from RH7777 cells expressing human LPA1 receptors was assayed by stimulating the cells with LPA in the presence of various test compounds to measure the test compounds' antagonism, i.e. activity in vitro. Approximately 10,000 cells in normal culture medium (Dulbecco's Modified Eagle Media, 10% Foetal Calf Serum) were dispensed per assay well in a black clear bottom collagen coated 384 well plate (Beckton Dickinson). Cells were allowed to settle for thirty minutes at room temperature before being incubated overnight at 37° C., 5% CO2. Sixteen to twenty hours after dispensing, the cells were loaded with a calcium-sensitive fluorescent dye by replacing the culture medium with assay buffer (1× Hanks buffered saline, 25 mM HEPES, 0.1% w/v fatty acid free BSA (bovine serum albumin), pH7.4) containing 1.25 mM probenecid and 1× Calcium 5 Reagent (Molecular Devices). Cells were incubated at 37° C. for one hour to allow for dye uptake. To test for antagonist activity, test compounds at a final concentration range between 0.32 nM-10 μM (diluted in assay buffer) were added to the assay wells and allowed to incubate for twenty five minutes. After incubation with test compounds the assay plate was placed in a FLIPR Tetra system (Molecular Devices) and LPA (diluted in assay buffer) was added to give a final concentration equivalent to its determined EC80 against LPA1 receptor. Ligand-dependent changes in intracellular calcium levels were determined by measuring changes in fluorescence of the dye over 515-575 nM following excitation over 470-495 nM.
- Measurement of Orexin Type 2 Receptor Agonist Activity Chinese hamster ovary (CHO) dhfr-cells forcibly expressing human orexin type 2 receptor (hOX2R) were seeded in each well of Black clear bottom plate (384 wells) (Becton, Dickinson and Company) by 10,000 cells, and cultured for 16 hr in an MEM-alpha (Nikken-Bio Co., Ltd.) medium containing 100 U/ml penicillin, 100 μg/ml streptomycin, 0.5 g/ml G418 (all above Invitrogen), and 10% fetal calf serum (Thermo), under the conditions of 37° C., 5% CO2. After removal of the medium, 30 μL of assay buffer 1 (0.1% bovine serum albumin (Wako Pure Chemical Industries, Ltd.), 1.25 mM probenecid, 10% B2-Quencher, 2.5 μg/mL Fluo-4AM, 10 mM HEPES (DOJINDO)) was added, and the cells were incubated for 60 min under the conditions of 37° C., 5% CO2. A test compound was dissolved in dimethyl sulfoxide to 10 mM, and then diluted with assay buffer 2 (20 mM HEPES, Hanks' balanced salt solution (Invitrogen), 0.1% bovine serum albumin). For the reaction, a test compound solution (10 μL) was added using Fluorescent Imaging Plate Reader TETRA (FLIPR TETRA; manufactured by Molecular Devices), a fluorescence value (excitation wavelength 488 nm, measurement wavelength 570 nm) of each well was measured every one second for 1 min, and the agonist activity was determined using the area of the fluorescence value as an indicator of intracellular Ca2+ concentration. The agonist activity of the test compound was calculated assuming that the fluorescence value of the well added with only the dilution buffer was 0% and the fluorescence value of the well added with 10 nM human orexin B (PEPTIDE INSTITUTE, INC.) buffer was 100%. The agonist activity values EC50 and Emax of each compound are shown below. As used herein, Emax indicates the value at 30 uM concentration when orexin B is converted to a full agonist (maximum value of agonist activity: 100%).
- Measurement of Orexin Type 2 Receptor Agonist Activity Chinese hamster ovary (CHO) dhfr-cells forcibly expressing human orexin type 2 receptor (hOX2R) were seeded in each well of Black clear bottom plate (384 wells) (Becton, Dickinson and Company) by 10,000 cells, and cultured for 16 hr in an MEM-alpha (Nikken-Bio Co., Ltd.) medium containing 100 U/ml penicillin, 100 μg/ml streptomycin, 0.5 g/ml G418 (all above Invitrogen), and 10% fetal calf serum (Thermo), under the conditions of 37° C., 5% CO2. After removal of the medium, 30 μL of assay buffer 1 (0.1% bovine serum albumin (Wako Pure Chemical Industries, Ltd.), 1.25 mM probenecid, 10% B2-Quencher, 2.5 μg/mL Fluo-4AM, 10 mM HEPES (DOJINDO)) was added, and the cells were incubated for 60 min under the conditions of 37° C., 5% CO2. A test compound was dissolved in dimethyl sulfoxide to 10 mM, and then diluted with assay buffer 2 (20 mM HEPES, Hanks' balanced salt solution (Invitrogen), 0.1% bovine serum albumin). For the reaction, a test compound solution (10 μL) was added using Fluorescent Imaging Plate Reader TETRA (FLIPR TETRA; manufactured by Molecular Devices), a fluorescence value (excitation wavelength 488 nm, measurement wavelength 570 nm) of each well was measured every one second for 1 min, and the agonist activity was determined using the area of the fluorescence value as an indicator of intracellular Ca2+ concentration. The agonist activity of the test compound was calculated assuming that the fluorescence value of the well added with only the dilution buffer was 0% and the fluorescence value of the well added with 10 nM human orexin B (PEPTIDE INSTITUTE, INC.) buffer was 100%. The agonist activity values EC50 and Emax of each compound are shown below. As used herein, Emax indicates the value at 30 uM concentration when orexin B is converted to a full agonist (maximum value of agonist activity: 100%). As is clear from the results, the compound of the present invention was shown to have an agonist activity on hOX2R.
- Calcium Mobilization Assay CHO-K1 EDG2 cells (DiscoverX cat #93-0644C2) expressing human LPAR1 (NM_001401.3) were seeded in a total volume of 25 μL of Dulbecco's Modification of Eagle's Medium (DMEM) with 10% Fetal Bovine Serum, 1× PenStrepGlutamine, 300 μg/ml Hygromycin, and 800 μg/ml G418 into 384-well tissue culture plate (Grenier #781091) at 15,000 cells/well and incubated at 37° C. overnight. Prior to testing, 25 μL Calcium Loading Dye Component A (FLIPR Calcium 6 Assay Kit Molecular Device #R8190) and 2.5 mM Probenecid (Invitrogen #P36400, prepared fresh) in Hank's Balanced Salt Solution (Corning #21-023-CV), 20 mM HEPES (Corning #25-060-CI), 0.1% Bovine Serum Albumin (Sigma-Aldrich #A7906-500G) was add to the cells for 60 minutes at 37° C.Agonist dose curves of LPA 18:2 (Avanti Polar Lipids cat #857138, 0.5 nM to 10 μM) were recorded to determine the LPA 18:2 EC80 for subsequent antagonist assays. For agonist dose curves, cells were removed from the incubator 2 hours after dye loading and transferred to the FLIPR Tetra instrument (Molecular Devices, San Jose, CA). Calcium mobilization was monitored for 5 min and 10 μL 6×LPA in HBSS/20 mM Hepes/0.1% bovine serum albumin (BSA) was added to the cells 5 seconds into the assay.To determine the LPAR1 antagonist activity of test compounds, cells were pre-incubated with test compound at a dose range of 0.5 nM to 10 μM, followed by LPA at EC80 concentration (100 nM). After dye loading, cells were removed from the incubator and 0.3 μL of 200× antagonist was added. Cells were incubated for 60 minutes at 37° C. Antagonist activity was measured on a FLIPR Tetra. Calcium mobilization was monitored for 3.5 minutes and 10 μL 6× EC80 LPA in HBSS, 20 mM HEPES, and 0.1% BSA was added to the cells 5 seconds into the assay. Signal amplitude (Maximum minus minimum) values were plotted against log10 of antagonist concentration using Dose Response T
- FLIPR Ca2+ Flux Assay The following table shows representative data for the compounds of the Examples as orexin receptor antagonists as determined by the FLIPR Ca2+ Flux Assay (Okumura et al., Biochem. Biophys. Res. Comm., 2001, 280:976-981). Chinese hamster ovary (CHO) cells expressing the human orexin-1 receptor (hOX1R) or the human orexin-2 receptor (hOX2R) were grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells were seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates were incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A, used as the agonist, was prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds were prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer.On the day of the assay, cells were washed 3× with 100 μl assay buffer and then incubated for 60 minutes (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution was then aspirated and cells were washed 3× with 100 μl assay buffer. 30 μl of that same buffer was left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds were added to the plate in a volume of 25 μl, incubated for 5 minutes, and then 25 μl of agonist was added. Fluorescence was measured for each well at 1 second intervals for 5 minutes, and the height of each fluorescence peak was compared to the height of the fluorescence peak induced by 70 pM of Ala-6,12 orexin-A with buffer in place of test compound.
- Intracellular Calcium Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist. For each antagonist, IC50 value (the concentration of compound needed to inhibit 50% of the agonist response) is determined.
- FLIPR Assay 1. Culture the cells in cell culture medium (DMEM containing 10% FBS 1× penicillin-streptomycin 300 μg/ml G418 and 100 μg/ml hygromycin B) at 37° C., 5% (v/v) CO2. One day before the assays, detach the cell using TrypLE Express and count cells using cell counter. Only cells with >85% viability are used for the assay. 3. Seed 20000 cells/well in 30 μl/well culture medium to a 384-well cell plate and incubate the cells overnight at 37° C., 5% (v/v) CO2. 4. On the assay day, prepare 2× dye solution following the manual of the FLIPR Calcium 6 Assay Kit: i. Dilute the dye with assay buffer (20 mM HEPES in 1×HBSS, PH7.4); ii. Add probenecid to the final concentration of 5 mM; iii. Vortex vigorously for 1-2 minutes. 5. Medium from cell plate by flicking the cell plate on towel papers. 6. Add 10 μl of assay buffer and 10 μl of 2× dye solution to each well of the cell plate. 7. Put the cell plate on plate shaker, agitate the plate at 600 rpm for 2 minutes. Incubate the plate at 37° C. for 2 hours followed by additional 15-minute incubation at 25° C. 8. Prepare 3× compound in assay buffer: a. Dilute reference compounds to required concentration with DMSO. Add the compounds to a 384-well compound plate; b. Perform serial dilutions; c. Add 10 mM test compounds to the compound plate, perform 3-fold serial dilutions. d. Transfer 60 nl/well of compounds from source plate to a 384-well compound plate (Corning, 3657) by using an Echo; e. Add 20 μl/well assay buffer to the compound plate; f. Mix the plate-on-plate shaker for 2 mins; 9. Put the cell plate, compound plate and tips into FLIPR, transfer 10 μl of 3× compound to the cell plate per well with FLIPR. I.d Data Analysis i. The normalized fluorescence reading (RFU) is calculated as shown follow, while Fmax and Fmin stand for maximum and minimum of calcium signal during defined time window: RFU=Fmax−Fmin
- FLIPR Assay The utility of the compounds in accordance with the present invention as orexin receptor OX1R and/or OX2R antagonists may be readily determined without undue experimentation by methodology well known in the art, including the FLIPR Ca2+ Flux Assay. In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist. For each antagonist, IC50 value (the concentration of compound needed to inhibit 50% of the agonist response) is determined.
- In Vitro M4 &M2 Functional Assay The functional activity of compounds at the M4 and M2 receptors was determined by measuring changes in the level of intracellular calcium ions caused by signalling cascades mediated by the receptor. Intracellular Calcium levels were measured using a calcium sensitive fluorescent dye, calcium 5 (Molecular Devices) The changes in fluorescence were monitored by a fluorescent imager, FLiPR Tetra (Molecular devices). Increases in intracellular calcium were readily detected upon activation of both receptors by the muscarinic receptor agonist Acetylcholine.CHOK1 cells stably expressing human M4 or M2 receptor and co-expressing the accessory g-protein Gα16 were routinely grown as monolayers in Hams-F12 medium (Invitrogen) supplemented with 10% foetal bovine serum (FBS) (Hyclone), 500 ug/mL Geneticin and 250 ug/mL zeocin (both invitrogen) in 5% CO2 at 37° C. Once confluent is cells cryopreserved by freezing at −186° C. in freezing solution (90% FBS 10% DMSO) (Sigma-Aldrich Co.). Twenty-four hours prior to testing cells resuscitated and freezing media removed via centrifugation, cells then seeded in a black walled clear bottom 384 well plates (Corning) at a density of 15,000 cells/well in Hams F12 media supplemented with 10% FBS. On the day of assay, growth media was removed and replaced with 63 μl of Calcium 5 dye solution (Molecular Devices) in assay buffer (HBSS, 20 mM HEPES, 0.1% BSA, 1 mM Probenecid pH7.4 (Sigma-Aldrich Co.)) per well (each vial of Calcium 5 resuspended in 27 mL of assay buffer). Cells were then incubated for 45 minutes at 37° C., 5% CO2. Compound was serially diluted in DMSO (log/half log) before being diluted 1:20 with assay buffer. 7 μl of compound diluted in assay buffer was then added to cells on FLiPR tetra and fluorescence intensity measured for 5 minutes. EC50 values for compounds were determined from ten point half log scale dose-response studies and represent the concentration of compound required to prevent 50% inhibition of its own maximal response. Curves were generated using the average of duplicate wells for each data point and analyzed using non-linear regression of four parameter dose response. Percentage Relative efficacy (RE) to an EC100 concentration of acetylcholine was reported for all compounds. The results are set out in Table 3 below in which the term No Response means that there was no significant response of calcium flux in the assay indicative of agonism.
- FLIPR Ca2+ Flux Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat or human orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist. For each antagonist, IC50 value (the concentration of compound needed to inhibit 50% of the agonist response) is determined. Alternatively, compound potency can be assessed by a radioligand binding assay (described in Bergman et. al. Bioorg. Med. Chem. Lett. 2008, 18, 1425-1430) in which the inhibition constant (Ki) is determined in membranes prepared from CHO cells expressing either the OX1 or OX2 receptor. The intrinsic orexin receptor antagonist activity of a compound which may be used in the present invention may be determined by these assays.
- FLIPR Ca2+ Flux Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist. For each antagonist, IC50 value (the concentration of compound needed to inhibit 50% of the agonist response) is determined. Alternatively, compound potency can be assessed by a radioligand binding assay (described in Bergman et. al. Bioorg. Med. Chem. Lett. 2008, 18, 1425-1430) in which the inhibition constant (Ki) is determined in membranes prepared from CHO cells expressing either the OX1 or OX2 receptor. The intrinsic orexin receptor antagonist activity of a compound which may be used in the present invention may be determined by these assays.
- FLIPR Ca2+ Flux Assay The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist. For each antagonist, IC50 value (the concentration of compound needed to inhibit 50% of the agonist response) is determined. Alternatively, compound potency can be assessed by a radioligand binding assay (described in Bergman et. al. Bioorg. Med. Chem. Lett. 2008, 18, 1425-1430) in which the inhibition constant (Ki) is determined in membranes prepared from CHO cells expressing either the OX1 or OX2 receptor. The intrinsic orexin receptor antagonist activity of a compound which may be used in the present invention may be determined by these assays.All of the final compounds of the following examples had activity in antagonizing the human orexin-2 receptor in the aforementioned assays with an IC50 of about 0.1 nM to 1500 nM. All of the final compounds of the following examples had activity in the FLIPR assay with an IC50 of about 5 nM to 500 nM against the orexin-2 receptor. Additional data is provided in the following Examples. Such a result is indicative of the intrinsic activity of the compounds in use as antagonists of orexin-1 receptor and/or the orexin-2 receptor. In general, one of ordinary skill in the art would appreciate that a substance is considered to effectively antagonize the orexin receptor if it has an IC50 of less than about 50 μM, or more specifically less than about 1000 nM.
- Intracellular Calcium Assay Cell Lines and Cell Culture.The PathHunter U2OS HTR2C β-Arrestin cell line (5-HT2cR-U2OS; DiscoveRx) stably express the nonedited human 5-HT2CR isoform (h5-HT2CR). The 5-HT2CR-U2OS cells were grown in Assay Complete U2OS Medium 31 (DiscoveRx) at 37° C., 5% CO2 and 85% relative humidity according to manufacturer's recommendations utilizing AssayComplete Cell Detachment Reagent (DiscoveRx). Cells were passaged at 70-80% confluence and all experiments were conducted using cells in log phase growth.Intracellular Calcium Assay.The ability of the molecules to act as agonists to induce 5-HT2CR-mediated intracellular calcium (Cai ++) release was conducted in an U2OS cell line stably expressing the human 5-HT2CR. For all molecules examined, the observed potency was shifted rightward relative to 5-HT or WAY163909 (Table 1).Intracellular calcium (Cai ++) release was monitored using the FLIPR Calcium 4 Assay Kit (Molecular Devices) according to previously published protocols with minor modifications. See, e.g., Shashack, M. J., et al., ACS Chem Neurosci. 2 (11), 640-644 (2011); Seitz, P. K.; Bremer, N. M., et al., BMC Neurosci. 13, 25 (2012).Cells were plated at 5,000-7,000 cells/well in Assay Complete Cell Plating Reagent 16 (DiscoveRx) in black-sided, clear bottomed 96-well tissue culture plates and allowed to adhere overnight. Medium was removed and replaced with 40 μl Hank's balanced salt solution without calcium, magnesium and phenol red (HBSS; Corning) plus 40 μl Calcium 4 dye solution in Buffer B supplemented with 2.5 mM probenecid (Sigma-Aldrich) to inhibit extracellular dye transport. Plates were incubated for 60 min at 37° C. followed by 30 min at room temperature in the dark.Fluorescence (λex=485 nm, λem=525 nm) was measured using a FlexStation3 (Molecular Devices). Baseline was established for 17 secs before addition of 20 μl vehicle (HBSS without calcium or magnesium) or 5× concentrated compound. Addition of 5-HT, WAY163909, or ligand occurred at the 17-sec time point and fluorescence was recorded every 1.7 sec for 120 sec. Maximum peak height was determined using FlexStation software (SoftMax Pro 5.4). After the final readings, cells were fixed in 2% paraformaldehyde overnight.Data AnalysisPeak responses from each well were normalized to total cell mass as determined with crystal violet staining. See e.g., Ding, C. et al., ACS Chem. Neurosci 3 (7), 538-545 (2012).
- Measurement of Antagonistic Activity Against Orexin Receptors The Chinese hamster ovary (CHO) cell lines CHOOX1R and CHOOX2R were established by modifying CHO cells to constantly express the NFAT-luciferase gene and either the human OX1R or human OX2R gene. Those cells were plated at 10,000 cells/well in 96-well multiplates with DMEM (manufactured by Sigma-Aldrich Co. LLC) supplemented with 5% FBS (manufactured by Thermo Scientific Inc.) and incubated at 37° C. and 5% CO2 for 48 hours. After removal of the medium, 100 μL of an assay buffer (20 mM HEPES (manufactured by Sigma-Aldrich Co. LLC), Hank's balanced salt solution (manufactured by Gibco), 0.1% BSA (manufactured by Sigma-Aldrich Co. LLC), 2.5 mM probenecid acid (manufactured by Wako Pure Chemical Industries, Ltd.), pH 7.4) containing 5 μM Fura-2AM (manufactured by Cayman Chemical Co.) was added to each well, and incubated at 37° C. and 5% CO2 for 60 minutes. After removal of the buffer containing Fura-2AM, 75 μL of the assay buffer was added to each well. Then, 25 L of the assay buffer containing a test compound at various concentrations and OX-A (manufactured by Peptide Institute, Inc.) was added to start the reaction. The change in intracellular calcium ion concentration induced by the reaction was evaluated by the ratio of fluorescent intensities, which were measured at a wavelength of 510 nm based on the two wavelength excitation approach using FDSS 7000 (manufactured by Hamamatsu Photonics K.K.) with fluorescence excitation at 340 nm and 380 nm. A concentration-response curve on the antagonistic activity was plotted from the values of maximal fluorescent intensity ratio determined when various concentrations of a test compound were added in the presence of 300 μM of OX-A, where a value of maximal fluorescent intensity ratio determined by adding 300 pM of OX-A alone corresponds to 100% and a value of maximal fluorescent intensity ratio determined by adding the assay buffer alone corresponds to 0%. Based on the resulting non-linear regression curve, the 50% maximal inhibitory concentration (IC50) was calculated. Each test compound was dissolved in DMSO to a concentration of 10 mM (the final concentration of DMSO was 1%), and then diluted with the assay buffer to give a final concentration of 3.0×10−10 M to 1.0×10−5 M (a common ratio of 3), while OX-A was diluted to a final concentration of 300 pM. The experiment was performed in quadruplicate plates, and the results of the four independent measurements were averaged to give the value of each reaction, and then the IC50 of a sample was calculated. If the sample number was 2 or more, the averaged IC50 was used.
- FLIPR Ca2+ Flux Assay The utility of the compounds in accordance with the present invention as orexin receptor OX1R and/or OX2R antagonists may be readily determined without undue experimentation by methodology well known in the art, including the FLIPR Ca2+ Flux Assay (Okumura et al., Biochem. Biophys. Res. Comm. 280:976-981, 2001). In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist. For each antagonist, IC50 value (the concentration of compound needed to inhibit 50% of the agonist response) is determined. Alternatively, compound potency can be assessed by a radioligand binding assay (described in Bergman et. al. Bioorg. Med. Chem. Lett. 2008, 18, 1425-1430) in which the inhibition constant (Ki) is determined in membranes prepared from CHO cells expressing either the OX1 or OX2 receptor. The intrinsic orexin receptor antagonist activity of a compound which may be used in the present invention may be determined by these assays.
- FLIPR assay The utility of the compounds in accordance with the present invention as orexin receptor OX1R and/or OX2R antagonists may be readily determined without undue experimentation by methodology well known in the art, including the FLIPR Ca2+ Flux Assay (Okumura et al., Biochem. Biophys. Res. Comm. 280:976-981, 2001). In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 μM Ala-6,12 orexin-A with buffer in place of antagonist. For each antagonist, IC50 value (the concentration of compound needed to inhibit 50% of the agonist response) is determined. Alternatively, compound potency can be assessed by a radioligand binding assay (described in Bergman et. al. Bioorg. Med. Chem. Lett. 2008, 18, 1425-1430) in which the inhibition constant (Ki) is determined in membranes prepared from CHO cells expressing either the OX1 or OX2 receptor. The intrinsic orexin receptor antagonist activity of a compound which may be used in the present invention may be determined by these assays.
- GLP-1 Assay with EX-4 Synthetic Agonist To assess the effects of test compounds on GLP-1 or glucagon potency and efficacy, a high-throughput calcium mobilization assay was used essentially as previously described (Morris L C, Days E L, Turney M, Mi D, Lindsley C W, Weaver C D, Niswender K D, A Duplexed High-Throughput Screen to Identify Allosteric Modulators of the Glucagon-Like Peptide 1 and Glucagon Receptors. J. Biomol. Screen. 2014 Feb. 13, 19(6):847-858). Briefly, human GLP-1R or Glucagon Receptor 9-3-H cells over-expressing a promiscuous G-protein (Millipore, Billerica, Mass.) were plated at 15,000 cells/well in black-walled 384-well plates (Greiner Bio-one, Monroe, N.C.) in Dulbecco's Modified Eagles Medium (DMEM) with 10% FCS, 4.0 mM L-glutamine, 1× non-essential amino acids (NEAAs), and 10.0 mM HEPES without antibiotics. After overnight attachment, cells were washed twice with assay buffer (HBSS supplemented with 20 mM HEPES and 1.0 mM probenecid) using an EL×405CW cell washer (Bio-Tek, Winooski, Vt.) and then loaded with the calcium sensitive dye fluo-4 AM (Invitrogen, Grand Island, N.Y.) at a final concentration of 2.0 μM in assay buffer. After a 45-minute incubation at room temperature, the dye was removed by washing, leaving 20 μL of assay buffer. Next, the cell plate was introduced alongside a 384-well compound plate containing 0.1% final DMSO control wells and 11-point concentration response curves of putative GLP-1 PAMs created using a non-pipet based liquid transfer instrument, ECH0555 (Labcyte, Sunnyvale, Calif.). After a 20 μL compound addition to the appropriate wells, kinetic fluorescent measurements were collected for 2 minutes using an FDSS6000 (Hamamatsu, Bridgewater, N.J.) with 488 nm excitation and 480/540 emission filters. After 2 minutes, 10 μL of an EC20 concentration of EX-4 (Phoenix Pharmaceuticals, Burlingame, Calif.), Glucagon (Phoenix Pharmaceuticals, Burlingame, Calif.) Exendin-4 (Tocris Bioscience, Bristol, UK), or Liraglutide (Victoza , Novo-Nordisk, Denmark) was added and fluorescence was monitored for an additional 2 minutes to observe potentiation of the calcium flux signal. Control wells for vehicle, EC20 peptide, and Emax peptide resided in columns #1 and 24 and rows H and I to account for any plate variations. Recombinant peptides were reconstituted into assay buffer supplemented with 0.1% fatty acid free BSA (Sigma #A6003) and diluted into borosilicate glass tubes to maximize peptide recovery (Goebel-Stengel M, Stengel A, Tach Y, Reeve J R Jr., The importance of using the optimal plasticware and glassware in studies involving peptides. Anal. Biochem. 2011 Jul. 1, 414(1):38-46).
- GLP-1 Assay with GLP1 Endogenous Agonist To assess the effects of test compounds on GLP-1 or glucagon potency and efficacy, a high-throughput calcium mobilization assay was used essentially as previously described (Morris L C, Days E L, Turney M, Mi D, Lindsley C W, Weaver C D, Niswender K D, A Duplexed High-Throughput Screen to Identify Allosteric Modulators of the Glucagon-Like Peptide 1 and Glucagon Receptors. J. Biomol. Screen. 2014 Feb. 13, 19(6):847-858). Briefly, human GLP-1R or Glucagon Receptor 9-3-H cells over-expressing a promiscuous G-protein (Millipore, Billerica, Mass.) were plated at 15,000 cells/well in black-walled 384-well plates (Greiner Bio-one, Monroe, N.C.) in Dulbecco's Modified Eagles Medium (DMEM) with 10% FCS, 4.0 mM L-glutamine, non-essential amino acids (NEAAs), and 10.0 mM HEPES without antibiotics. After overnight attachment, cells were washed twice with assay buffer (HBSS supplemented with 20 mM HEPES and 1.0 mM probenecid) using an ELx405CW cell washer (Bio-Tek, Winooski, Vt.) and then loaded with the calcium sensitive dye fluo-4 AM (Invitrogen, Grand Island, N.Y.) at a final concentration of 2.0 μM in assay buffer. After a 45-minute incubation at room temperature, the dye was removed by washing, leaving 20 μL of assay buffer. Next, the cell plate was introduced alongside a 384-well compound plate containing 0.1% final DMSO control wells and 11-point concentration response curves of putative GLP-1 PAMs created using a non-pipet based liquid transfer instrument, ECH0555 (Labcyte, Sunnyvale, Calif.). After a 20 μL compound addition to the appropriate wells, kinetic fluorescent measurements were collected for 2 minutes using an FDSS6000 (Hamamatsu, Bridgewater, N.J.) with 488 nm excitation and 480/540 emission filters. After 2 minutes, 10 μL of an EC20 concentration of GLP-1 peptide 7-36 amide (Phoenix Pharmaceuticals, Burlingame, Calif.), Glucagon (Phoenix Pharmaceuticals, Burlingame, Calif.) Exendin-4 (Tocris Bioscience, Bristol, UK), or Liraglutide (Victoza , Novo-Nordisk, Denmark) was added and fluorescence was monitored for an additional 2 minutes to observe potentiation of the calcium flux signal. Control wells for vehicle, EC20 peptide, and Emax peptide resided in columns #1 and 24 and rows H and I to account for any plate variations. Recombinant peptides were reconstituted into assay buffer supplemented with 0.1% fatty acid free BSA (Sigma #A6003) and diluted into borosilicate glass tubes to maximize peptide recovery (Goebel-Stengel M, Stengel A, Tache Y, Reeve J R Jr., The importance of using the optimal plasticware and glassware in studies involving peptides. Anal. Biochem. 2011 Jul. 1, 414(1):38-46).
- mGlu2 Ca2+ Flux Assay Gα15 HEK293 cells stably expressing rat mGlu2 were plated in black-walled, clear-bottomed, poly-D-lysine coated 384-well plates in 20 μL of assay medium (DMEM containing 10% dialyzed FBS, 20 mM HEPES, and 1 mM sodium pyruvate) at a density of 12K cells/well. The cells were grown overnight at 37° C. in the presence of 5% CO2. The next day, medium was removed and the cells incubated with 20 μL of 2.3 LM Fluo-4, AM prepared as a 2.3 mM stock in DMSO and mixed in a 1:1 ratio with 10% (w/v) pluronic acid F-127 and diluted in assay buffer (Hank's balanced salt solution, 20 mM HEPES, and 2.5 mM probenecid) for 45 minutes at 37° C. Dye was removed, 20 μL of assay buffer was added, and the plate was incubated for 5 minutes at room temperature.Ca2+ flux was measured using the Functional Drug Screening System (FDSS7000, Hamamatsu, Japan). After establishment of a fluorescence baseline for about 3 seconds, the compounds of the present invention were added to the cells, and the response in cells was measured. 2.3 minutes later an EC20 concentration of the mGlu2 receptor agonist glutamate was added to the cells, and the response of the cells was measured for 1.9 minutes; an EC80 concentration of agonist was added and readings taken for an additional 1.7 minutes. All test compounds were dissolved and diluted to a concentration of 10 mM in 100% DMSO. Compounds were then serially diluted 1:3 in DMSO into 10 point concentration response curves, transferred to daughter plates, and further diluted into assay buffer to a 2× stock. Calcium fluorescence measures were recorded as fold over basal fluorescence; raw data was then normalized to the maximal response to glutamate. Antagonism of the agonist response of the mGlu2 receptor in the present invention was observed as a decrease in response to nearly maximal concentrations of glutamate in the presence of compound compared to the response to glutamate in the absence of compound.The raw data file containing all time points was used as the data source in the analysis template. This was saved by the FDSS as a tab-delimited text file. Data were normalized using a static ratio function (F/F0) for each measurement of the total 360 values per well divided by each well's initial value. Data were then reduced to peak amplitudes (Max−Initial Min) using a time range that starts approximately 3 seconds prior to the glutamate EC80 addition and continues for approximately 90 seconds. This is sufficient time to capture the peak amplitude of the cellular calcium response. Individual amplitudes were expressed as % ECMax by multiplying each amplitude by 100 and then dividing the product by the mean of the amplitudes derived from the glutamate ECMax-treated wells. IC50 values for test compounds were generated by fitting the normalized values versus the log of the test compound concentration (in mol/L) using a 4 parameter logistic equation where none of the parameters were fixed. Each of the three values collected at each concentration of test compound were weighted evenly.
- FLIPR Ca2+ Flux Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4 AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist. For each antagonist, IC50 value (the concentration of compound needed to inhibit 50% of the agonist response) is determined. Alternatively, compound potency can be assessed by a radioligand binding assay (described in Bergman et. al. Bioorg. Med. Chem. Lett. 2008, 18, 1425-1430) in which the inhibition constant (Ki) is determined in membranes prepared from CHO cells expressing either the OX1 or OX2 receptor. The intrinsic orexin receptor antagonist activity of a compound which may be used in the present invention may be determined by these assays.All of the final compounds of the following examples had activity in antagonizing the human orexin-2 receptor in the aforementioned assays with an IC50 of about 0.1 nM to 1500 nM. All of the final compounds of the following examples had activity in the FLIPR assay with an IC50 of about 5 nM to 500 nM against the orexin-2 receptor. Additional data is provided in the following Examples. Such a result is indicative of the intrinsic activity of the compounds in use as antagonists of orexin-1 receptor and/or the orexin-2 receptor.
- FLIPR Ca2+ Flux Assay In a typical experiment the OX1 and OX2 receptor antagonistic activity of the compounds of the present invention was determined in accordance with the following experimental method. For intracellular calcium measurements, Chinese hamster ovary (CHO) cells expressing the rat orexin-1 receptor or the human orexin-2 receptor, are grown in Iscove's modified DMEM containing 2 mM L-glutamine, 0.5 g/ml G418, 1% hypoxanthine-thymidine supplement, 100 U/ml penicillin, 100 μg/ml streptomycin and 10% heat-inactivated fetal calf serum (FCS). The cells are seeded at 20,000 cells/well into Becton-Dickinson black 384-well clear bottom sterile plates coated with poly-D-lysine. All reagents were from GIBCO-Invitrogen Corp. The seeded plates are incubated overnight at 37° C. and 5% CO2. Ala-6,12 human orexin-A as the agonist is prepared as a 1 mM stock solution in 1% bovine serum albumin (BSA) and diluted in assay buffer (HBSS containing 20 mM HEPES, 0.1% BSA and 2.5 mM probenecid, pH7.4) for use in the assay at a final concentration of 70 pM. Test compounds are prepared as 10 mM stock solution in DMSO, then diluted in 384-well plates, first in DMSO, then assay buffer. On the day of the assay, cells are washed 3 times with 100 μl assay buffer and then incubated for 60 min (37° C., 5% CO2) in 60 μl assay buffer containing 1 μM Fluo-4AM ester, 0.02% pluronic acid, and 1% BSA. The dye loading solution is then aspirated and cells are washed 3 times with 100 μl assay buffer. 30 μl of that same buffer is left in each well. Within the Fluorescent Imaging Plate Reader (FLIPR, Molecular Devices), test compounds are added to the plate in a volume of 25 μl, incubated for 5 min and finally 25 μl of agonist is added. Fluorescence is measured for each well at 1 second intervals for 5 minutes and the height of each fluorescence peak is compared to the height of the fluorescence peak induced by 70 pM Ala-6,12 orexin-A with buffer in place of antagonist. For each antagonist, IC50 value (the concentration of compound needed to inhibit 50% of the agonist response) is determined. Alternatively, compound potency can be assessed by a radioligand binding assay (described in Bergman et. al. Bioorg. Med. Chem. Lett. 2008, 18, 1425-1430) in which the inhibition constant (Ki) is determined in membranes prepared from CHO cells expressing either the OX1 or OX2 receptor. The intrinsic orexin receptor antagonist activity of a compound which may be used in the present invention may be determined by these assays.All of the final compounds of the following examples had activity in antagonizing the human orexin-2 receptor in the aforementioned assays with an IC50 of about 0.1 nM to 100 nM. All of the final compounds of the following examples had activity in the FLIPR assay with an IC50 of about 5 nM to 500 nM against the orexin-2 receptor. Additional data is provided in the following Examples. Such a result is indicative of the intrinsic activity of the compounds in use as antagonists of orexin-1 receptor and/or the orexin-2 receptor. In general, one of ordinary skill in the art would appreciate that a substance is considered to effectively antagonize the orexin receptor if it has an IC50 of less than about 50 μM, or more specifically less than about 100 nM.
- mGlu3 Ca2+ Flux Assay Gα15/TREx cells stably expressing rat mGlu3 were plated in black-walled, clear-bottomed, poly-D-lysine coated 384-well plates in 20 μL of assay medium (DMEM containing 10% dialyzed FBS, 20 mM HEPES, 25 ng/mL tetracycline, 100 units/mL penicillin/streptomycin plus 250 ng/mL Fungizone, and 1 mM sodium pyruvate) at a density of 15K cells/well. The cells were grown overnight at 37° C. in the presence of 5% CO2. The next day, medium was removed and the cells incubated with 20 μL of 2.3 LM Fluo-4, AM prepared as a 2.3 mM stock in DMSO and mixed in a 1:1 ratio with 10% (w/v) pluronic acid F-127 and diluted in assay buffer (Hank's balanced salt solution, 20 mM HEPES, and 2.5 mM probenecid) for 60 minutes at room temperature. Dye was removed, 20 μL of assay buffer was added, and the plate was incubated for 10 minutes at room temperature.Ca2+ flux was measured using the Functional Drug Screening System (FDSS7000, Hamamatsu, Japan). After establishment of a fluorescence baseline for about 3 seconds, the compounds of the present invention were added to the cells, and the response in cells was measured. 2.3 minutes later an EC20 concentration of the mGlu3 receptor agonist glutamate was added to the cells, and the response of the cells was measured for 1.9 minutes; an EC80 concentration of agonist was added and readings taken for an additional 1.7 minutes. All test compounds were dissolved and diluted to a concentration of 10 mM in 100% DMSO. Compounds were then serially diluted 1:3 in DMSO into 10 point concentration response curves, transferred to daughter plates, and further diluted into assay buffer to a 2× stock. Calcium fluorescence measures were recorded as fold over basal fluorescence; raw data was then normalized to the maximal response to glutamate. Antagonism of the agonist response of the mGlu3 receptor in the present invention was observed as a decrease in response to nearly maximal concentrations of glutamate in the presence of compound compared to the response to glutamate in the absence of compound.The raw data file containing all time points was used as the data source in the analysis template. This was saved by the FDSS as a tab-delimited text file. Data were normalized using a static ratio function (F/F0) for each measurement of the total 360 values per well divided by each well's initial value. Data were then reduced to peak amplitudes (Max−Initial Min) using a time range that starts approximately 3 seconds prior to the glutamate EC80 addition and continues for approximately 90 seconds. This is sufficient time to capture the peak amplitude of the cellular calcium response. Individual amplitudes were expressed as % EMax by multiplying each amplitude by 100 and then dividing the product by the mean of the amplitudes derived from the glutamate ECMax-treated wells. EC50 values for test compounds were generated by fitting the normalized values versus the log of the test compound concentration (in mol/L) using a 4 parameter logistic equation where none of the parameters were fixed. Each of the three values collected at each concentration of test compound were weighted evenly.
- mGlu5 Ca2+ Flux Assay HEK 293A cells stably expressing rat mGlu5 were plated in black-walled, clear-bottomed, poly-D-lysine coated 384-well plates in 20 μL of assay medium (DMEM containing 10% dialyzed FBS, 20 mM HEPES, 100 units/mL penicillin/streptomycin plus 250 ng/mL Fungizone, and 1 mM sodium pyruvate) at a density of 20K cells/well. The cells were grown overnight at 37° C. in the presence of 5% CO2. The next day, medium was removed and the cells incubated with 20 μL of 2.3 LM Fluo-4, AM prepared as a 2.3 mM stock in DMSO and mixed in a 1:1 ratio with 10% (w/v) pluronic acid F-127 and diluted in assay buffer (Hank's balanced salt solution, 20 mM HEPES, and 2.5 mM probenecid) for 45 minutes at 37° C. Dye was removed, 20 μL of assay buffer was added, and the plate was incubated for 5 minutes at room temperature.Ca2+ flux was measured using the Functional Drug Screening System (FDSS7000, Hamamatsu, Japan). After establishment of a fluorescence baseline for about 3 seconds, the compounds of the present invention were added to the cells, and the response in cells was measured. 2.3 minutes later an EC20 concentration of the mGlu5 receptor agonist glutamate was added to the cells, and the response of the cells was measured for 1.9 minutes; an EC80 concentration of agonist was added and readings taken for an additional 1.7 minutes. All test compounds were dissolved and diluted to a concentration of 10 mM in 100% DMSO. Compounds were then serially diluted 1:3 in DMSO into 10 point concentration response curves, transferred to daughter plates, and further diluted into assay buffer to a 2× stock. Calcium fluorescence measures were recorded as fold over basal fluorescence; raw data was then normalized to the maximal response to glutamate. Potentiation of the agonist response of the mGlu5 receptor in the present invention was observed as an increase in response to submaximal concentrations of glutamate in the presence of compound compared to the response to glutamate in the absence of compound. Antagonism of the agonist response of the mGlu5 receptor in the present invention was observed as a decrease in response to nearly maximal concentrations of glutamate in the presence of compound compared to the response to glutamate in the absence of compound.The raw data file containing all time points was used as the data source in the analysis template. This was saved by the FDSS as a tab-delimited text file. Data were normalized using a static ratio function (F/F0) for each measurement of the total 360 values per well divided by each well's initial value. Data were then reduced to peak amplitudes (Max−Initial Min) using a time range that starts approximately 3 seconds prior to the glutamate EC20/EC80 addition and continues for approximately 90-120 seconds. This is sufficient time to capture the peak amplitude of the cellular calcium response. Individual amplitudes were expressed as % EMax by multiplying each amplitude by 100 and then dividing the product by the mean of the amplitudes derived from the glutamate ECMax-treated wells. EC50 values for test compounds were generated by fitting the normalized values versus the log of the test compound concentration (in mol/L) using a 4 parameter logistic equation where none of the parameters were fixed. Each of the three values collected at each concentration of test compound were weighted evenly