骨髓基质细胞促进永久性局灶性脑缺血大鼠脑室下区的神经发生

THE PROMOTION OF NEUROGENESIS IN SUBVENTRICULAR ZONE BY BONE MARROW STROMAL CELLS AFTER PERMANENT FOCAL CEREBRAL ISCHEMIA IN RATS

目的探讨移植骨髓基质细胞(BMSCs)对永久性局灶性脑缺血大鼠脑室下区(SVZ)细胞增殖的影响及其增殖细胞类型分析。方法制作永久性局灶性脑缺血大鼠模型,分为空白对照组(MCAO)、PBS对照组(MCAO+PBS)和治疗组(MCAO+BMSCs),每组动物再分为脑缺血后7d和14d亚组。空白对照组不予处理,PBS对照组在脑缺血后1d移植PBS,治疗组在脑缺血后1d移植BMSCs。用Zausinger六分法检测神经功能恢复情况;注射5-溴脱氧鸟嘧啶核苷(BrdU)标记SVZ的新增殖细胞,免疫荧光双重标记检测新增殖细胞的类型。结果在脑缺血后7d和14d,与两个对照组相比,治疗组的神经功能评分较高,有显著性差异(P<0.05);脑缺血后14d,治疗组的大鼠患侧SVZ的BrdU阳性细胞较其余两组高,存在显著差异(P<0.05);免疫荧光双重标记显示,新增殖细胞表达神经元和星形胶质细胞的标志物,提示新增殖细胞为神经元和神经胶质细胞的混合体。结论BMSCs可以改善永久性局灶性脑缺血大鼠的神经功能,其机制可能与促进SVZ的神经细胞增殖有关。

Objective To investigate the effect of transplanted bone marrow stromal cells on the cells in the subventricular zone of the rats with permanent focal cerebral ischemia and analyze cell types. Methods Permanent focal cerebral ischemia models were established with middle cerebral artery occlusion （MCAO） and divided into three groups： MCAO alone, intravenous infusion of lml PBS at 24 hours after MCAO, and intravenous infusion of 2 × 10^6 BMSCs 24 hours after MCAO. Then, the groups were subdivided into 7-day and 14-day groups after MACO. Neurological functions were detected by Zausinger evaluation; meanwhile, 5-bromodeoxyuridine was injected to label the proliferating cells in the subventricular zone, and double-immunofluscent technologies were used to identify the cell type. Results On the 7th day and the 14th day after MACO, neurological functional scores of BMSCs-treated group were higher than those of the other two groups （ P 〈 0.05）. On the lgth day after MCAO, BrdU- positive cells in SVZ of ipsilateral ischemia of BMSCs-treated group were more than those in the two controls （ P 〈 0.05） ; doubleimmunofluorescence label demonstrated that BrdU-positive were collocated with markers of neuron and astrocyte. Conclusion BMSCs can promote the neurological function of the rats with permanent focal cerebral ischemia and this action may be related with the neurogenesis in the subventricular zone.