Expressions of Bcl-2 and Bax and apoptotic rate of bone marrow mesenchymal stem cells transfected with thymosin beta4 in a hypoxic environment / 中国组织工程研究

ABSTRACT

BACKGROUND:Studies have shown that thymosinβ4 can improve the anti-apoptotic ability of a variety of cells, but the reports describing the changes in the anti-apoptotic ability of bone mesenchymal stem cells modified with thymosinβ4 gene in the hypoxic environment are rare. OBJECTIVE:To observe the change in the apoptotic rate of bone mesenchymal stem cells modified with thymosinβ4 gene in the hypoxic environment, and to explore whether thymosinβ4 affects the apoptosis of bone marrow mesenchymal stem cells via regulating the expression of Bax and Bcl-2. METHODS:Bone marrow mesenchymal stem cells were transfected with the recombinant lentiviral vector over-expressing the thymosinβ4 gene, and then we observed the expression of thymosinβ4 using western blot assay. cells were divided into three groups:thymosinβ4 transfection group, control virus group, and untreated group. Al three groups were placed in a hypoxic environment. The apoptotic rate of bone marrow mesenchymal stem cells was evaluated by the flow cytometry assay. The expression of Bax and Bcl-2 protein was detected by western blot. RESULTS AND CONCLUSION:Thymosinβ4 gene was expressed successful y in the bone marrow mesenchymal stem cells showed by the western blot. The apoptotic rate of bone marrow mesenchymal stem cells in the hypoxic environment was lower in the thymosinβ4 transfection group than the control virus group and untreated group;while there was no difference between the latter two groups. Western blot results showed that the expression of Bcl-2 protein was higher in the thymosinβ4 transfection group than the control virus group and untreated group, and the expression of Bax protein was lower in the thymosinβ4 transfection group than the control virus group and untreated group. No difference in the expression of Bax and Bcl-2 was found between the control virus group and untreated group. These findings indicate that thymosinβ4 overexpression can improve the anti-apoptotic ability of bone mesenchymal stem cells modified in the hypoxic environment, and its possible mechanism is through regulating the expression of Bax and Bcl-2 protein.