外胚间充质干细胞向小胶质细胞分化的研究

目的观察外胚间充质干细胞（EMSCs）在大鼠胶质瘤模型中枢神经系统（CNS）内的分化方向。方法将大鼠c6胶质瘤细胞系微量注射入12只SD大鼠（4～6周龄）右侧纹状体内，建立大鼠胶质瘤模型；C6细胞移植后2d，Hoechst33342标记EMSCs移植到SD大鼠双侧纹状体内。EMSCs移植后7d行全脑组织冰冻切片，免疫荧光染色观察细胞表面标记OX-42（CD11b/CD11a）的表达，荧光显微镜下观察标记效果。结果SD大鼠全脑组织切片观察证实12只大鼠脑胶质瘤模型建立成功；Hoechst33342标记EMSCs阳性率达95％以上；荧光显微镜镜下观察显示注射人大鼠体内的EMSCs经过7d后大部分细胞都保持存活状态。同时有V6细胞和EMSCs存在的时候，C6细胞周围存在大量OX-42阳性细胞；而只有c6细胞或只有EMSCs时，OX-42阳性的细胞数量非常少。另外，远离c6细胞的EMSCs具有向c6细胞迁移的特性。结论在SD大鼠胶质瘤模型纹状体内中，EMSCs大多数被C6细胞诱导成为具有吞噬和抗原提呈功能的小胶质细胞。

Differentiation of ecto-mesenchymal stem cells into microglias induced by C6 cells in rats

Objective To observe the differentiation of ecto-mesenchymal stem cells （EMSCs） in central nervous system （CNS） in rat with C6 glioma. Methods The rat glioma cell line C6 cells were micro-injected into the right corpora striata of 12 SD rats （aged 4-6 weeks） to make the rat glioma model. Two days later, the EMSCs labeled with Hoechst 33342 were implanted into the left and right corpora striata in the rats with C6 ceils gliomas. The rats were killed and the whole brain tissues were isolated 9 days after the injection of C6 cells. The expression of OX42 （CD1 lb/CD1 lc） in the corpora strita was determined by immunohistochemical technique to detect the microglias in all the rats. Results The C6 glioma models were successfully established in all 12 rats. The most EMSCs （95%） labeled with Hoechst 33342 survived in the rat brain. A large number of OX42 positive ceils were observed in the rat corpora striata containing C6 cells and EMSCs. But only a few of OX42 positive cells were observed in the rat corpora striata containing C6 cells and EMSCs alone. In the rats that C6 glioma cells and EMSCs separated in the two sides of the brain, the EMSCs migrated to the side that containing C6 glioma cells. Conclusion Most EMSCs can differentiate into the microglias in the corpora striata containing C6 cells in the rats.