Figure 9A-C. Effect of MSDK on MAPKs, ERK1/2 and ERK5. After 21 days of MSDK exposure, western blot was performed to determine (A) ERK1/2 expression of osteoblasts grown as transwell co-cultures, (B) ERK1/2 expression of osteoblasts and osteoclasts grown as layered co-cultures, (C) ERK5 expression of osteoblasts grown as transwell co-cultures.