转基因修饰后的自体骨髓间充质干细胞移植治疗mdx鼠后成肌调节因子的表达研究

Dynamic Changes in the Expression of Myogenic Regulatory Factors in Mdx Mice after Micro-Dystrophin Gene Modified Autologous Bone Mesenchymal Stems Cells Transplantation

目的探讨携带micro-dystrophin基因的自体骨髓间充质干细胞移植入mdx鼠后在移植鼠体内分化为肌细胞的可能机制。方法采用逆转录病毒介导micro-dystrophin基因转染mdx小鼠MSCs(mMSCs),通过尾静脉注射移植治疗mdx鼠,在移植后免疫荧光检测micro-dystrophin的表达并在不同时间点检测MyoD的表达。结果移植后成功检测到micro-dystrophin,其表达随着移植时间的延长而增加;随移植时间延长MyoD阳性肌纤维比例增加,分别达到9%(4周时)、15%(8周时)、28%(12周时)。RT-PCR和Westernblot也发现,随着移植时间的延长,MyoD表达增加。结论自体mMSCs可携带外源性micro-dystrophin基因在受体鼠体内分化为micro-dystrophin阳性肌细胞,移植入的干细胞向肌细胞的分化是一个持久的、连续的过程,成肌调节因子在调节其分化过程中发挥了重大作用。

Objective To study the mechanism of differentiation of genetically modified autologous mesenchymal stem cells into functional muscle cells in transplanted mdx mice.Methods mMSCs were infected with retrovirus containing micro-dystrophin and transplanted into mdx mice through tail vein.After transplantation,the expression of micro-dystrophin was determined using immunofluorescence.The expression of MyoD was also determined.Results After transplantation,micro-dystrophin positive fibers were increased in the gastrocnemius.By immunofluorescence,RT-PCR and Western blotting methods,the expression of MyoD was also found to be time-dependently increased.Conclusion The genetically modified autologous MSCs was found to differentiate into micro-dystrophin positive cells in transplanted mdx mice,and myogenic regulatory factors appeared to play a key pole in this process.