Antagonist activity at P2X7 receptor in human PBMC assessed as inhibition of BzATP-induced IL1beta release incubated 30 mins prior to BzATP-challenge measured after 1.5 hrs by ELISA method
Antagonist activity at human recombinant P2X7 receptor expressed in human 1321N1 cells assessed as inhibition of BzATP-induced Ca2+ flux after 30 mins by FLIPR assay
Antagonist activity at P2X7 receptor in human whole blood assessed as inhibition of BzATP-induced IL1beta release incubated 30 mins prior to BzATP-challenge measured after 1.5 hrs by ELISA method
Radioligand Binding Assay: human or rat P2X7-1321N1 cells were collected and frozen @ −80° C. On the day of the experiment, cell membrane preparations were made according to standard published methods. The total assay volume was 100 μl:10 μl compound (10×)+(b) 40 μl tracer (2.5x)+50 μl membrane (2×). The tracer used for the assay was tritiated A-804598. The compound can be prepared as described in the literature. (Donnelly-Roberts, D. Neuropharmacology 2008, 56 (1), 223-229.) Compounds, tracer and membranes were incubated for 1 hour @ 4° C. The assay was terminated by filtration (GF/B filters pre-soaked with 0.3% PEI) and washed with washing buffer (Tris-HCl 50 mM).
FLIPR Assay: 1321N1 cells expressing the recombinant human, rat or mouse P2X7 channel was cultured in HyQ DME/(HyClone/Dulbecco's Modified Eagle Medium) high glucose supplemented with 10% Fetal Bovine Serum (FBS) and appropriate selection marker. Cells were seeded at a density of 25000 cells/well (96-well clear bottom black walled plates) in 100 ul volume/well. On the day of the experiment, cell plates were washed with assay buffer, containing (in mM): 130 NaCl, 2 KCl, 1 CaCl2, 1 MgCl2, 10 HEPES, 5 glucose; pH 7.40 and 300 mOs. After the wash, cells were loaded with the Calcium-4 dye (Molecular Device) and incubated in the dark for 60 minutes. Test compounds were prepared at 250x the test concentration in neat DMSO. Intermediate 96-well compound plates were prepared by transferring 1.2 uL of the compound into 300 uL of assay buffer. A further 3x dilution occurred when transferring 50 uL/well of the compound plate to 100 uL/well in the cell plate.
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.
FLIPR Assay: Ca.sup.2+flux: 1321N1 cells expressing the recombinant human, rat or mouse P2X7 channel was cultured in HyQ DME/(HyClone/Dulbecco's Modified Eagle Medium) high glucose supplemented with 10% Fetal Bovine Serum (FBS) and appropriate selection marker. Cells were seeded at a density of 25000 cells/well (96-well clear bottom black walled plates) in 100 .mu.l volume/well. On the day of the experiment, cell plates were washed with assay buffer, containing (in mM): 130 NaCl, 2 KCl, 1 CaCl.sub.2, 1 MgCl.sub.2, 10 HEPES, 5 glucose; pH 7.40 and 300 mOs. After the wash, cells were loaded with the Calcium-4 dye (Molecular Device) and incubated in the dark for 60 minutes. Test compounds were prepared at 250.times. the test concentration in neat DMSO. Intermediate 96-well compound plates were prepared by transferring 1.2 .mu.L of the compound into 300 .mu.L of assay buffer. A further 3.times. dilution occurred when transferring 50 .mu.L/well of the compound plate to 100 .mu.L/well in the cell plate.
Radioligand Binding: Human or rat P2X7-1321N1 cells were collected and frozen @-80.degree. C. On the day of the experiment, cell membrane preparations were made according to standard published methods. The total assay volume was 100 .mu.l:10 .mu.l compound (10.times.)+(b) 40 .mu.l tracer (2.5.times.)+50 .mu.l membrane (2.times.). The tracer used for the assay was tritiated A-804598. The compound can be prepared as described in the literature. (Donnelly-Roberts, D. Neuropharmacology 2009, 56 (1), 223-229.) Compounds, tracer and membranes were incubated for 1 hour @ 4.degree. C. The assay was terminated by filtration (GF/B filters pre-soaked with 0.3% PEI) and washed with washing buffer (Tris-HCl 50 mM).
FLIPR Assay: Ca2+ Flux: 1321N1 cells expressing the recombinant human, rat or mouse P2X7 channel was cultured in HyQ DME/(HyClone/Dulbecco's Modified Eagle Medium) high glucose supplemented with 10% Fetal Bovine Serum (FBS) and appropriate selection marker. Cells were seeded at a density of 25000 cells/well (96-well clear bottom black walled plates) in 100 ul volume/well. On the day of the experiment, cell plates were washed with assay buffer, containing (in mM): 130 NaCl, 2 KCl, 1 CaCl2, 1 MgCl2, 10 HEPES, 5 glucose; pH 7.40 and 300 mOs. After the wash, cells were loaded with the Calcium-4 dye (Molecular Device) and incubated in the dark for 60 minutes. Test compounds were prepared at 250x the test concentration in neat DMSO. Intermediate 96-well compound plates were prepared by transferring 1.2 uL of the compound into 300 uL of assay buffer. A further 3x dilution occurred when transferring 50 uL/well of the compound plate to 100 uL/well in the cell plate.
Radioligand Binding Assay: Radioligand binding: human or rat P2X7-1321N1 cells were collected and frozen @ −80° C. On the day of the experiment, cell membrane preparations were made according to standard published methods. The total assay volume was 100 μl:10 μl compound (10×)+(b) 40 μl tracer (2.5×)+50 μl membrane (2×). The tracer used for the assay was tritiated A-804598. The compound can be prepared as described in the literature. (Donnelly-Roberts, D. Neuropharmacology 2009, 56 (1), 223-229.) Compounds, tracer and membranes were incubated for 1 hour @ 4° C. The assay was terminated by filtration (GF/B filters pre-soaked with 0.3% PEI) and washed with washing buffer (Tris-HCl 50 mM).
Antagonist activity at human P2X7R expressed in BzATP-stimulated human 1321N1 cells incubated for 20 mins followed by BzATP stimulation measured every 1 sec for 60 secs followed by 3 sec intervals for 4 mins by FLIPR Ca2+ assay in presence of ionomycin
Antagonist activity at P2X7R in human whole blood assessed as inhibition of LPS-induced IL-1beta production incubated for 30 mins followed by ATP addition for 30 mins by ELISA assay
Antagonist activity at P2X7 receptor expressed in LPS/IFNgamma-differentiated human THP1 cells assessed as inhibition of BzATP-induced IL-1beta production at 1 uM after 4 hrs by ELISA
Antagonist activity at P2X7 receptor expressed in LPS/IFNgamma-differentiated human THP1 cells assessed as inhibition of BzATP-induced IL-1beta production after 4 hrs by ELISA
Potency index, ratio of KN62 IC50 to compound IC50 for human P2X7 receptor expressed in HEK293 cells assessed as inhibition of BzATP-induced ethidium ion uptake after 2 hrs