Effect Of Osteocytic Wnt/Beta-Catenin Signaling Pathway On Osteoblastic Differentiation Of BMSCs

Objective:To determine the effect of osteocytic Wnt/?-Catenin signaling on osteoblastic differentiation in bone marrow stromal cells(BMSCs)and its molecular mechanism.Methods:Mice with osteocytic Wnt activation(da?catOt)were generated previously by crossing DMP1-8kb-Cre mice with catnblox(ex3)mice.The osteocytes were isolated from Wnt activation mice and wild type mice.Then the two types osteocytes were separately co-cultured with wild-type BMSCs.The expression of osteocytic Notch ligands Jagl,Jag2,Dll1 and D112 were detected by qPCR.ALP staining and Alizarin red staining were performed to measure osteoblastic differentiation in co-culture.Next,osteoblastic marker genes were detected by qPCR.Furthermore,Notch signaling inhibitor DAPT was applied to the co-culture and osteoblastic marker genes were detected by qPCR.ALP staining and Alizarin red staining were performed.Results:The expression of Jagl,Jag2 and D114 mRNA in da?catOtosteocytes was significantly higher than the control(P<0.05).In the co-culture,the expression of osteoblastic makers Runx2,ALP and Osteocalcin mRNA was significantly higher than the control(P<0.05),and the deposition of calcium also increased compared to the control.The expression of osteoblastic transcription factors Runx2,ALP and Osteocalcin mRNA decreased significantly treated with Notch inhibitor DAPT in da?catOt osteocytes co-culture(P<0.05).Conclusion:Osteocyte can regulate bone metabolism,and activation of Osteocytie Wnt/?-Catenin signaling pathway can promote osteogenic differentiation of BMSCs via upregulation of Notch signaling.