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.
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.
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).
Antagonist activity at human recombinant P2X7 receptor expressed in 1321N1 cells assessed as inhibition of BzATP-induced calcium mobilization incubated for 30 mins measured after 180 seconds by calcium-4 dye based FLIPR assay
Antagonist activity at rat P2X7 receptor expressed in 1321N1 cells assessed as inhibition of BzATP-induced calcium mobilization incubated for 30 mins measured after 180 seconds by calcium-4 dye based FLIPR assay