α- 玉米赤霉醇影响小鼠骨髓间充质干细胞的成骨分化简

背景：骨髓间充质干细胞具有向成骨细胞分化的能力，植物雌激素α-玉米赤霉醇对小鼠骨髓间充质干细胞的成骨分化可能有促进作用。 目的：探讨α-玉米赤霉醇对小鼠骨髓间充质干细胞向成骨细胞分化的影响。 方法：采用全骨髓培养差速贴壁法体外分离培养小鼠骨髓间充质干细胞，取第3代细胞分为6组：非诱导组加含体积分数为10%胎牛血清、1%双抗的 IMDM 普通培养基；空白诱导组仅加入等量成骨条件培养基（含0.1μmol/L 地塞米松、10 mmol/Lβ-甘油磷酸钠、50μmol/L 维生素C）；阳性对照诱导组加入等量成骨条件培养基及10-8 mol/L雌二醇；高、中、低α-玉米赤霉醇组分别加入成骨条件培养基及10-5，10-6，10-7 mol/L梯度浓度的α-玉米赤霉醇。倒置显微镜下观察细胞形态变化，MTT 实验测定细胞增殖状态绘制细胞生长曲线，酶联免疫吸附法测定碱性磷酸酶、骨钙素的表达。 结果与结论：非诱导组细胞呈长梭形，生长密集时有接触抑制，各诱导组的细胞增殖受促进，诱导后细胞呈三角形、多角形、不规则形状，细胞可重叠生长；非诱导组低表达碱性磷酸酶、骨钙素，低浓度（10-7 mol/L）α-玉米赤霉醇组和阳性对照诱导组高表达碱性磷酸酶、骨钙素，与空白诱导组相比，差异有非常显著性意义（P＜0.01）。结果说明α-玉米赤霉醇可以促进骨髓间充质干细胞的增殖，低浓度α-玉米赤霉醇可显著促进体外培养的小鼠骨髓间充质干细胞成骨分化。而上调碱性磷酸酶、骨钙素的表达量可能是α-玉米赤霉醇诱导促进骨髓间充质干细胞骨向分化的作用机制之一。

Effects of alpha-zearalanol on the osteogenic differentiation of mouse bone marrow mesenchymal stem cells

BACKGROUND：Bone marrow mesenchymal stem cells can differentiate into osteoblasts, andα-zearalanol can promote the osteogenic differentiation of mouse bone marrow mesenchymal stem cells. OBJECTIVE：To observe the effects ofα-zearalanol on the osteogenic differentiation of mouse bone marrow mesenchymal stem cells. METHODS：Mouse bone marrow mesenchymal stem cells were isolated through whole bone marrow adherence method. Passage 3 cells were divided into non-induced group （cultured by the Iscove’s modified Dulbecco’s medium containing 10%fetal bovine serum and 1%penicil in and streptomycin）, blank induced group （induced by the classic osteoblast-induced system with 0.1μmol/L dexamethasone, 10 mmol/Lβ-glycerine sodium, and 50μmol/L vitamin C）, positive control induced group （induced by the classic osteoblast-induced system and 10-8 mol/L oestrogen）, and low-, median-, high-concentrationα-zearalanol groups （induced by the classic osteoblast-induced system and 10-7, 10-6, 10-5 mol/Lα-zearalanol）. The morphological changes of induced cells were observed by phase contrast microscopy, and the growth curves of cultured cells were plotted based on MTT results. The expression of alkaline phosphatase and osteocalcin were detected by ELISA. RESULTS AND CONCLUSION：In the non-induced group, cells showed long fusiform shape mostly, and contact inhibition was observed while the cells were close-packed. After induced, cells proliferated effectively, showed triangle, astero-form, polygon or irregular shape, and clumps and multilayer of cells became evident. Compared to both the blank induced group, the alkaline phosphatase activity and osteocalcin expression were significantly lower in the non-induced group, but higher in the positive control induced group and low concentrationα-zearalanol group （P〈0.01）. These findings indicate thatα-zearalanol can promote the proliferation of bone marrow mesenchymal stem cells, and enhance the expression of alkaline phosphatase and osteocalcin expression, especial y in the low concentration group. This demonstrates that low concentrationα-zearalanol obviously enhances the osteogenic differentiation of mouse bone marrow mesenchymal stem cells in vitro. Up-regulating the release of alkaline phosphatase and osteocalcin may be one of the mechanisms by whichα-zearalanol promotes osteogenic differentiation of bone marrow mesenchymal stem cells.