端粒酶活性在骨髓间充质干细胞体外分化过程中的表达观察

Telomerase activity during in vitro committed differentiation of rabbit bone marrow mesenchymal stem cells

为了探讨兔骨髓间充质干细胞体外增殖前后及诱导分化内皮细胞过程中端粒酶活性的表达及意义 ,我们联合应用密度梯度离心和贴壁培养法分离骨髓间充质干细胞 ,继而诱导其向内皮细胞方向分化 ,用TRAPezeELISA法分别检测新鲜分离的骨髓细胞及骨髓间充质干细胞、原代培养的内皮样细胞及传代细胞端粒酶活性 ,结果发现新鲜分离的骨髓细胞及增殖前的骨髓间充质干细胞端粒酶活性低水平表达 ,一旦经过VEGF诱导分化 ,细胞端粒酶活性表达上调 ,在 5代内其端粒酶活性不因细胞传代而下降或消失 ,说明骨髓间充质干细胞体外有限扩增和诱导分化时保持端粒酶活性 ,维持组织干细胞特性 。

To investigate the telomerase activity in mesenchymal stem cells from rabbit bone marrow during their in vitro committed differentiation and its significance. Rabbit bone marrow was aspirated from the iliac crest sterilely with heparin. Bone marrow mononuclear cells were isolated by gradient density centrifugation with lymphocyte separation medium.Mesenchymal stem cells(MSCs) were then obtained and cultured in endothelial cell complete medium to differentiate into endothelial cells.The telomerase activity was analyzed during different periods by TRAPeze ELISA respectively. Telomerase activity was at lower level in freshly isolated bone marrow mononuclear cells and MSCs premultiplication. Once induced by vascular endothelial growth factor (VEGF), bone marrow MSCs were expanded potentially ex vivo , and their telomerase activity was soon upregulated and kept at a higher level in five passages. Telomerase activity observed in bone marrow MSCs expansion in vitro is a theoretical basis of clinical investigation on adult stem cell.