Fig. 2

PMA activates the MAPK/ERK pathway. BMSCs were cultured in standard medium for 7 days. Cells were lysed at different time points (pretreatment and 10 min and overnight (O/N) after 100 nM PMA treatment), and the cell extracts (protein) were analyzed by Western blotting. a Representative blots of ERK1/2 and phospho-ERK1/2 (Thr202/Tyr204) are shown. b The bar graph shows the densitometric analysis of phosphorylation normalized to the basal expression of ERK1/2. n = 3 (^**P < 0.01 vs. vehicle control)