The Study On The Relationship Between BMP9-induced Osteogenic Differentiation And Wnt10b In Mscs

Bone defect and non-union are the common Orthopedic diseases in clinic.In recent years,BMP9 had become one of the most possible candidates for the treatment of the diseases due its strong osteogenesis induction effect on MSCs.However,there must be another factor to enhance the effect.As its crucial role in osteogenic and adipogenic differentiation in MSCs,Wnt10b could be a potential protein which may enhance the effects of BMP9.So,this study is aimed to find the relationships between the Wnt10b and BMP9 and illustrate how Wnt10b may influence BMP9-induced osteogenic differentiation in MSCs.In this study,the results show that Wnt10b could express in different stem cells,and its mRNA level could be up-regulated by BMP9.Then,in vitro,exogenous Wnt10b could strengthen the effect induced by BMP9,which could up-regulate osteogenic marker(Runx2,Dlx-5,OPN and OCN)at mRNA and protein level.Besides,exogenous Wnt10b could promote BMP9-induced mineralization in C3H10T1/2 cells,While Wnt10b knockdown could downregulate these effects.In vivo,overexpressed Wnt10b could lead to a increasing bone mass induced by BMP9.On the contrary,this effect could be decreased when Wnt10b were silenced.Next,further experiments show that the reason why theinduction effect are promoted may be because Wnt10b could up-regulate the protein level of p-Smad1/5/8 while adipogenic differentiation are suppressed in C3H10T1/2 cells.Finally,we also found BMP9 could upregulate COX-2 and phosphorylation of CREB.COX-2 could promote the effect of BMP9 on Wnt10b.The interaction between p-CREB and p-Smad1/5/8 may regulate the expression of Wnt10b.In conclusion,Wnt10b could promote BMP9-induced osteogenic differentiation in MSCs,and the axis of COX-2/CREB could play a key role in the process of BMP9 enhancing the expression of Wnt10b.