Fig. 5.

Effects of NGF upon osteoclast differentiation in vitro. Human peripheral mononuclear cells were isolated and cultured in the presence of MCSF with (A) or without (B) RANKL, and increasing concentrations of NGF, for 14 days. TRAP +ve cells were counted using four random fields of vision on four separate slides for each condition. RANKL alone significantly increased TRAP +ve cells as compared to MCSF alone (A). For RANKL treated cells, addition of NGF significantly decreased osteoclast numbers at 50 and 100 ng/ml. In the absence of RANKL (B), addition of NGF caused a small non-dose related significant increase in TRAP +ve cell number. (C) Examples of TRAP staining in the presence and absence of RANKL. Scale bar is 100 μm. Data are mean ± SEM, statistical analysis: one way ANOVA, *P < 0.05, **P < 0.01, ***P < 0.001.