Differentiation of SOX-9 and GDF-5 co-transfected bone marrow mesenchymal stem cells into nucleus pulposus cells / 中国组织工程研究

ABSTRACT

BACKGROUND:Transplantation of mesenchymal stem cels to prevent and treat degeneration of the intervertebral disc is a feasible method. Mesenchymal stem cels co-transfected by SRY-related high mobility group-box gene 9 (SOX-9) and growth differentiation factor-5 (GDF-5) can differentiate into nucleus pulposus cels, in order to obtain greater effect of induction and proliferation of nucleus pulposus cels. OBJECTIVE:To investigate the effect of SOX-9 and GDF-5 co-transfection on the differentiation of rabbit bone marrow mesenchymal stem cels into nucleus pulposus cels. METHODS: We separated and cultured bone marrow mesenchymal stem cels from the bone marrow of rabbit aged 4 months. Passage 3 cels were divided into five groups andin vitro induced to differentiate into nucleus pulposus cels non-transfected group, empty vector transfection group, SOX-9 transfection group, GDF-5 transfection group, SOX-9 and GDF-5 co-transfection group. At 14 days after transfection, RT-PCR was employed to assay SOX-9, GDF-5 and colagen type II mRNA expressions in bone marrow mesenchymal stem cels. The marker of nucleus pulposus cels-KRT19 expression was also detected by immunohistochemical staining. RESULTS AND CONCLUSION:In the co-transfection group, the mRNA expressions of SOX-9, GDF-5, and colagen type II were significantly higher than those in the SOX-9 transfection group, GDF-5 transfection group, and both these two groups, respectively (P < 0.05). Cels were positive for KRT19 in the SOX-9 and GDF-5 groups, and strongly positive for KRT19 in the co-transfection group. These findings indicate that double gene-transfected bone marrow mesenchymal stem cels are better than single gene-transfected cels with regard to differentiation into nucleus pulposus cels and secretion of extracelular matrix.