Figure 6.

Effect of rapamycin on BMP-4-stimulated OPG release in MC3T3-E1 cells. Cultured cells were pretreated with the indicated doses of rapamycin for 60 min, then stimulated with 30 ng/ml BMP-4 (●) or vehicle (○) for 48 h. Levels of OPG in the culture medium were determined by ELISA. Data are presented as the mean ± standard error of the mean of three replicate experiments from three independent cell preparations. *P<0.05 vs. BMP-4 alone. BMP-4, bone morphogenic protein-4; OPG, osteoprotegrin.