Experimental Study On Mechanisms Of Osteoblasts Proliferation Mediated By ERK5under Cyclic Fluid Shear Stress

Objective:To investigate the changes of osteoblasts proliferation under cyclic fluid shear stress(cFSS) and the role of ERK5and transfer to the nucleus in this process to discuss the effect of osteoblasts proliferation and its mechanism through applying the mouse-derived MC3T3-E1cells to cyclic fluid shear stress.Methods:Randomly divided into A, B, C, D after using BrdU labeled osteoblasts(MC3T3-E1) in vitro. A group, the control group, B group,12dyne/cm2cFSS, C group,12dyne/cm2cFSS+10μM BIX02189, D group,10μM BIX02189. Using immunofluorescence chemical technology and image analysis software IPP various components analysis of osteoblasts proliferation and ERK.5activation and translocation, and using western blotting to analyze the expression of ERK.5and P-ERK5. Statistical analysis was performed using SPSS16.0software package for one way analysis of variance (ANOVO). Multiple comparisons were applied using LSD, P<0.05was considered significant.Results:A group of cells in a normal state, Compared with A group, the positive rate of cell proliferation in B group increased by200%(P<0.05), while ERK.5activation volume (integrated optical density value, IOD) increased by30%(P<0.05), the expression of P-ERK5was significantly increased. Compared with A group, the positive rate of cell proliferation in C group increased by40%(P<0.05), while The activation of ERK.5was no significant difference in volume (P>0.05),Compared with C group and A group, the positive rate of cell proliferation in D group decreased50%(P<0.05) and70%(P<0.05),while ERK5activation was all reduced by30%(P<0.05), the expression of P-ERK5was significantly decresed.Conclusion:These results indicate that cyclic fluid shear stress can promote osteoblasts proliferation,ERK5plays an important role in cyclical in mediating the cyclic fluid shear stress to promote the proliferation of osteoblasts.