The Influence Of Fluid Shear Stress On Osteoblast Proliferation Mediated By Beta-catenin

[Object]To explore the functions ofβ-catenin and cyclinDl in fluid shear stress(Fss) induced proliferation of mouse pre-osteoblast cell line(mc3t3-e1). [Method] Double-labbled immunofluorescence relative quantitative analysis was used to detect the espression ofβ-catenin and cyclinD1 in mc3t3-e1 cells which were under different intensity of fss(6dyn/cm2,12dyn/cm2,18dyn/cm2)after different time(15min,30min,60min) exposed by flow chamber.The ability of proliferation of these cells was studied through the changes of proliferation index(PI) calculated by flow cytomertry.[Result] The expression ofβ-catenin and cyclinD1 induced by moderate fss and PI were increased compared with static control, low and high intensity of fss(p<0.05).The expression betweenβ-catenin and cyclinD1 were of positive correlation (r=0.65, p<0.05). [Conclusion] Fss inducedβ-catenin accumulation in the cytoplasm,and then can be translocated to the nucleus,play a role as transcription factor to increase the. expression of targeted protein cyclinD1.β-catenin cooperation with cyclinD1 play a important role in G1→S transition of mc3t3-e1 proliferation. Moderate fss is a optimization that can promote proliferation of mc3t3-e1;The mc3t3-el cells were not as sensitive to the low intensity fss as to the moderate fss;The high intensity of fss inhibited the proliferation of mc3t3-e1 cells in the earlier period. So we presume that the mc3t3-e1 cells have a exact regulatory mechanism when these cells were forced with fss.In other word,these cells can adapt to fss, this adaptivity were dependent on the intensity of the fss and even more how long the fss last.