Fig. 6.

M2–10 and M3–10 block Pg-induced osteoclastogenesis. (A) M2–10 and M3–10 block RANKL-mediated priming during RANKL pretreatment that is required for Pg-induced osteoclastogenesis. WT BMMs were pretreated 8 μM M2–10 plus 8 μM M3–10, or 8 μM iM2–10 plus 8 μM iM3–10, in the presence of M-CSF (40 ng/ml) for 7 hours and RANKL (100 ng/ml) was then added. 1 day later, RANKL was removed and the cultures were continued with M-CSF (40 ng/ml) plus Pg (m.o.i. = 50) for 3 days. The cultures were then stained for TRAP activity. A representative area of the cultures from each condition is shown. Scale bar = 500 μM. (B) Quantification of assays in Fig. 6A. Data are expressed as mean ± S.D. of three independent experiments. ***, p < 0.001. (C) The addition of M2–10 and M3–10 after RANKL pretreatment had no effect on Pg-induced osteoclastogenesis. The culture of BMMs was similar to that described for A except that M2–10 and M3–10 were added after RANKL pretreatment. Scale bar = 500 μM. (D) Quantification of assays in Fig. 6C. Data are expressed as mean ± S.D. of three independent experiments. ***, p < 0.001. (E) The proposed model for the molecular mechanism by which RANKL pretreatment facilitates Pg-induced osteoclastogenesis.