人骨髓间质干细胞成骨向脂肪转分化的研究

目的建立人骨髓来源的间质干细胞成骨向脂肪转分化的体外培养条件，为了解成骨向脂肪转分化的分子机制和骨质疏松的发病机制提供基础。方法运用Haynesworth法分离出间质干细胞，经向成骨细胞和脂肪细胞诱导分化后，将分化后的成骨细胞向脂肪细胞转分化诱导，碱性磷酸酶（ALP）、油红O染色后，RT-PCR检测转分化效果。结果转分化后的脂肪细胞强表达脂蛋白脂肪酶（LPL）和过氧物酶体增殖物激活受体y2（PPARy2），弱表达ALP，但完全不表达骨钙素（OC）；转分化后的脂肪细胞与正常脂肪细胞相似，油红0染色显示脂滴在胞质内积聚成小泡。结论本试验建立了hMSCs成骨向脂肪转分化的体外培养体系，为了解骨质疏松的发病机制奠定了基础；hMSCs向脂肪定向分化优于向成骨分化。

Adipogenic and osteogenic differentiation from human bone marrow-derived mesenchymal stem cells and transdifferentiation from osteoblasts to adipocytes in vitro

Objective To establish a cell culture system for adipogenic and osteogenic differentiation from human bone marrow-derived mesenchymal stem cells and transdifferentiation from osteoblasts to adipocytes. Methods Haynesworth approach was adopted to isolate hMSCs. After adipogenic and osteogenic differentiation, hMSCs were transdifferentiated from adipocytes to osteoblasts. Alkaline phosphatase staining, Oil Red staining and RT-PCR were adopted to examine the effectiveness of transdifferentiation. Results Adipogenic markers lipoprotein lipase and peroxisome proliferator- activated receptor y2 （ PPAR-y2 ） was strongly expressed and osteogenic marker alkaline phosphatase was weakly expressed in transdifferentiated adipocytes, but osteogenic marker osteocalcin was not expressed. Oil Red O staining showed that the homogeneous accumulation of lipids in cytoplasmicvesicles of transdifferentiated cells, as in the hMSC-derived differentiated adipocytes. Conclusion Transdifferentiated culture system from osteogenesis to adipogenesis has been established and in hMSCs the adipogenic differentiation was excelled to osteogenic differentiation.