Human Umbilical Cord Mesenchymal Stem Cells Prevent And Treat Steroid Induced Avascular Necrosis Of Femoral Head In Rats

Objective:To investigate the effect of human umbilical cord mesenchymal stem cells(hUCMSC)on steroid induced avascular necrosis of femoral head in rats.Methods:Thirty SD rats were randomly divided into three groups: control group,model group and stem cell treatment group.Four weeks later,the femoral head tissue was isolated.The incidence of empty bone lacunae was evaluated by HE staining.The bone mineral density and microstructure of the femoral head were evaluated by micro CT.The apoptosis level of osteoblasts was evaluated by TUNEL staining.The protein expressions of bcl-2,bax and Caspase-3 in osteoblasts were detected by Western blot.Results:The incidence of steroid induced avascular necrosis of femoral head in the control group,model group and stem cell treatment group was 0(0 / 12),80%(8 / 10)and 10%(1/ 10).The rate of empty bone lacunae and osteoblast apoptosis in the model group were significantly higher than those in the control group.Human umbilical cord mesenchymal stem cells could significantly improve the above situation(P < 0.05).Micro CT results showed that the cortical thickness,the number of trabeculae and bone mineral density decreased in the model group,and the above indexes were significantly improved in the stem cell treatment group(P < 0.05).Western blot results showed that compared with the control group,the expression of Bcl-2 protein in the model group was decreased,while the expression of Caspase-3 and Bax protein was increased.Compared with the model group,the expression of Bcl-2 protein was increased and the expression of Caspase-3 and Bax protein was decreased in the stem cell treatment group(P < 0.05).Conclusion:Human umbilical cord mesenchymal stem cells may inhibit glucocorticoid induced osteoblast apoptosis by regulating the expression of Bax,Bcl-2 and caspase-3.