Figure 3.

Absence of P2X7 inhibits osteoclast differentiation. (A) Mouse bone marrow-derived macrophages were differentiated in the presence of macrophage colony-stimulating factor and receptor activator of the nuclear factor-κB (NF-κB) ligand for 1, 2, 3, 4 and 5 days. The expression of P2X7R was examined using western blot analysis. ^**P<0.01 vs. control. (B and C) Cells were transfected with negative control-shRNA and P2X7R-shRNA for 48 h, and the expression of P2X7R was then examined using western blot analysis and staining with TRAP (magnification, ×50). ^**P<0.01. (D) Cells were treated with A438079 (P2X7 inhibitor) for 12 h. After 5 days, TRAP staining was performed to analyze osteoclast numbers. ^**P<0.01. Data are representative of three independent experiments. PYK2, phosphorylated protein tyrosine kinase 2; TRAP, tartrate-resistant acidic phosphatase.