Hydrostatic pressure promotes Wnt10b and Wnt4 expression dependent and independent on ERK signaling in early-osteoinduced MSCs.

Recent publications have shown that mechanical stress can regulate the direction of stem cell differentiation. The exact mechanobiological effects of pressure on initial osteodifferentiation have not been determined. Here, we show that ERK signaling participates in early osteodifferentiation and plays a positive but non-critical role in mechanotransduction, whereas p38 MAPK is not involved in this process. Moreover, our findings provide evidence that in response to both types of pressure with high sensitivity, Wnt10b mRNA is ERK-dependent whereas Wnt4 mRNA is upregulated by treatment of the inhibitor of ERK signaling. The findings suggest novel mechanisms of the initial biological responses of bone remodeling and regeneration upon mechanical stimuli.