Fig. 3.

O-1602 and LPI stimulate Rho activation and ERK phosphorylation in human and mouse osteoclasts. (A) Human osteoclasts were treated with O-1602 (O), LPI, or CBD for 10 min, with or without a 10-min pre-incubation with 1 μM CBD. Activation of Rho and ERK1/2 was measured on Western blots by densitometry; values are means ± SEM from 3–7 independent experiments. **, P < 0.01; ***, P < 0.001 compared with control (Ctrl); #, P < 0.05 compared with O-1602 or LPI alone (ANOVA, with Bonferroni pos-test). (B) Mouse osteoclasts generated from wild-type macrophages (black bars) or GPR55^−/− macrophages (white bars) were starved for 30 min and then were treated as above before measurement of Rho activation (n = 2 experiments).