17β-雌二醇对大鼠骨髓间充质干细胞向成骨细胞分化的诱导调控*****☆

背景：研究发现骨髓间充质干细胞上存在雌激素受体，雌激素通过调节骨髓间充质干细胞的增殖、分化特性发挥促成骨作用。 目的：观察17β-雌二醇对骨髓间充质干细胞向成骨细胞分化的诱导作用，并探讨其作用机制。 方法：在基础成骨诱导培养基培养的第3代大鼠骨髓间充质干细胞中分别加入0(对照组)，0.001，0.01，0.1 nmol/L 17β-雌二醇干预。Elisa法检测培养的骨髓间充质干细胞分泌Ⅰ型胶原的水平，RT-PCR及Western blotting法分别检测Runx2因子mRNA及蛋白水平。 结果与结论：与对照组比较，在给予0.001，0.01，0.1 nmol/L 17β-雌二醇干预后第5天，骨髓间充质干细胞Ⅰ型胶原表达显著升高(P < 0.05)，第7天仍旧呈高表达(P < 0.05)。同时，在17β-雌二醇干预的第5，7天，Runx2因子mRNA及蛋白表达水平随17β-雌二醇浓度的增加而升高(P < 0.05)，并呈剂量依赖性。表明17β-雌二醇可诱导骨髓间充质干细胞向成骨细胞转化，其可能通过上调Runx2因子表达发挥促成骨作用。 关键词：诱导分化；骨髓间充质干细胞；17β-雌二醇；Ⅰ型胶原；Runx2 doi:10.3969/j.issn.1673-8225.2012.10.003

Effects of 17 beta-estradiol on osteogenic differentiation of rat primary cultured bone marrow mesenchymal stem cells

BACKGROUND: The estrogen receptor exists in bone marrow mesenchymal stem cells and estrogen promotes bone formation by regulating the proliferation and differentiation of bone marrow mesenchymal stem cells. OBJECTIVE: To explore the effects of 17β-estradiol on the osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs) and the underlying mechanism. METHODS: MSCs were separated, purified, cultured and expanded. Different concentrations of 17β-estradiol was administrated to MSCs for some period. The level of type I collagen in culture medium was detected by Elisa method, and the expression of Runx2 mRNA and protein was analyzed by RT-PCR or Western blotting methods, respectively. RESULTS: Compared with the control group, type I collagen expression in the MSCs was significantly increased on the 5th day after administration of 0.001, 0.01, 0.1 nmol/L 17β estradiol (P < 0.05) and it maintained high expression on the 7th day (P < 0.05). Runx2 mRNA expression increased in a dose-dependent manner on the 5th and 7th days after administration of 17 β-estradiol (P < 0.05). These findings suggest that 17β-estradiol can induce the osteogenic differentiation of MSCs, which occurs possibly by upregulation of Runx2 expression.