【摘要】 目的研究成肌性标志物在人骨髓间充质干细胞(hBM-MSCs)分化为肌细胞过程中的表达情况。方法体外培养hBM-MSCs,采用免疫荧光法和RT-PCR检测hBM-MSCs中成肌性标志物MyoD、myogenin及desmin的表达。将1×107个hBM-MSCs经尾静脉注入免疫抑制的mdx小鼠体内,于移植后2~24周处死,采用免疫荧光法和RT-PCR检测小鼠骨骼肌内MyoD、myogenin、desmin和人特异性抗肌萎缩蛋白(Dys)的表达。结果每100个hBM-MSCs中MyoD、myogenin和desmin阳性细胞数分别为23.5±5.3、30.7±6.2和28.4±5.7,第5代hBM-MSCs中可检测到MyoD、myo-genin和desmin mRNA表达。hBM-MSCs移植后2周,mdx小鼠骨骼肌内可检测到少量MyoD和myogenin阳性细胞,4周后可检测到少量desmin阳性细胞。hBM-MSCs移植后2~4周,骨骼肌中开始出现MyoD和myogenin mRNA表达,12~16周较强;移植后8周开始出现desmin mRNA表达,16周后表达渐增强。hBM-MSCs移植后4周,mdx小鼠骨骼肌肌膜可见少量人特异性Dys阳性细胞,8周后开始出现Dys mRNA表达,随着移植后时间延长,Dys表达逐渐增强。结论 hBM-MSCs具有向骨骼肌细胞分化的潜力,能在受体内分化为骨骼肌细胞。在hBM-MSCs分化为肌细胞的过程中,MyoD和myogenin表达上调可能发挥了重要作用。更多还原

【Abstract】 Objective To investigate the expressions of myogenic markers MyoD,myogenin,and desmin in skeletal muscle differentiation of human bone marrow mesenchymal stem cells(hBM-MSCs).Methods Myogenic markers MyoD,myogenin,and desmin of hBM-MSCs cultured in vitro were detected by immunofluorescence and RT-PCR.A total of 21 8-to-10 week-old immunosuppressed mdx mice were transplanted with 1×107 passage 5 of hBM-MSCs.The mice were euthanized 2-24 weeks after transplantation,and gastrocnemius muscle were analyzed for human MyoD,myogenin,desmin,and dystrophin(Dys)expressions by immunohistochemistry and RT-PCR.Results The numbers of MyoD-,myogenin-,and desmin-positive cells per 100 hBM-MSCs were 23.5±5.3,30.7±6.2,and 28.4±5.7,respectively.MyoD,myogenin,and desmin mRNA was observed in passage 5 of hBM-MSCs.After two weeks of hBM-MSCs transplantation,a small number of MyoD-and myogenin-positive cells were observed in skeletal muscle of mdx mice,and desmin-positive cells were observed 4 weeks after transplantation.Expressions of MyoD and myogenin were detected in the muscle of mdx mice 2-4 weeks after hBM-MSCs transplantation,which reached a peak 12-16 weeks later.Desmin was expressed in the muscle of mdx mice 4-8 weeks after transplantation,with much more expression after 16 weeks of transplantation.A small number of Dys-positive cell and Dys mRNA expression were presented in the muscle of mdx mice 4 and 8 weeks after hBM-MSCs transplantation,respectively.The expression of Dys in the muscle of mdx mice increased gradually after transplantation.Conclusion hBM-MSCs have the potential of myogenic differentiation in vitro and contribute to myogenic conversion in xenogeneic animal,during which the up-regulation of MyoD and myogenin expressions may play an important role.更多还原