过表达Olig2的少突胶质前体细胞在缺血缺氧脑白质损伤新生大鼠脑内的分化

The differentiation of Olig2-overexpresed OPCs graft in neonatal rats with hypoxia-ischemia-induced cerebral white matter damage

目的:观察过表达特异性转录因子Olig2的少突胶质前体细胞(oligodendrocyte precursor cells,OPCs)移植在缺血缺氧(hypoxia-ischemia,HI)脑白质损伤新生大鼠脑内的分化情况。方法:用绿色荧光蛋白(green fluorescent protein,GFP)标记的过表达Olig2的慢病毒感染原代分离纯化的大鼠大脑皮层OPCs,GFP阳性细胞计数测其感染率。将过表达Olig2的OPCs(Olig2组)或阴性对照病毒感染的OPCs(Vector组)脑立体定位注射到造模后7 d的HI模型大鼠胼胝体膝部,移植后2周,冰冻切片行免疫荧光染色观察OPCs的存活和分化情况。结果:Olig2-GV218病毒感染OPCs细胞48 h,荧光显微镜检测显示85%左右的OPCs细胞表达GFP;移植后2周,caspase-3荧光染色表明移植后绝大部分细胞存活,Vector组和Olig2组之间无统计学差异(P>0.05);GFAP/GFP双阳性细胞在两组之间也无显著差异(P>0.05);而Olig2组MBP/GFP双阳性细胞的荧光密度显著高于Vector组(P<0.05)。结论:过表达Olig2可促进移植OPCs向少突胶质细胞分化。

Objective： To observe the differentiation of Olig2-overexpressed oligodendrocyte precursor cells （OPCs） graft in neonatal rats with hypoxia - ischemia （HI）-induced cerebral white matter damage. Methods： Green fluorescent protein （GFP） labeled Olig2-GV218 was used to infect the OPCs which primary cultured and identificated from cerebral cortex of newborn SD rat, and the GFP positive cells were observed by fluorescence microscope. Olig2-OPCs （ Olig2 group） or negative control virus infected OPCs （Vector） were injected to the knee of the corpus callosum of 7 d HI model rats by brain stereotaxic injection. At 2 weeks after transplantation, staining were performed on frozen sections to observe the survival and differentiation of OPCs. Results： The OPCs were infected with O1ig2- GV218 and about 85% GFP positive OPCs were observed by fluorescence microscope after 48 h. At 2 weeks after trans- plantation, the immunofluorescence staining of caspase-3 showed most of the ceils were survival, no significant differ- ence in the number of caspase-3 positive cells was found between vector group and Olig2 group （P 〉 0. 05）. And there was no significant difference （P 〉 0. 05） in the number of GFAP/GFP double positive cells between vector group and Olig2 group. However, the fluorescence intensity of MBP/GFP double positive cells in Olig2 group was notably increased compared with vector group （ P 〈 0.05）. Conclusion： Overexpressed Olig2 can facilitate the differentiation of transplanted OPCs into oligodendrocytes.