尾静脉移植骨髓间充质干细胞对脑缺血再灌注大鼠模型的治疗作用

Therapeutic effect of intravenous injection of bone marrow mesenchymal stem cells on cerebral ischemia in rats

目的探讨静脉移植骨髓间充质干细胞(BMSCs)治疗脑梗死的疗效及其机制。方法全骨髓贴壁法分离、培养BMSCs;流式细胞仪鉴定BMSCs;线栓法制作MCAO大鼠模型;采用粘附实验和改良神经功能损伤评分(mNSS)评估大鼠的行为功能恢复;直接免疫荧光法检测Brdu标记的BMSCs;免疫组织化学染色检测大鼠脑组织NSE、Nogo-A、SYN、Ki-67、GFAP、VEGF表达;Bielshowsky's-Luxol fast blue双染检测神经纤维的变化。结果 BMSCs中表达CD106,低表达CD34、CD45、CD11b,高表达CD90、CD29。BMSCs移植后MCAO大鼠模型的神经功能明显好转(P<0.05),梗死侧的神经纤维明显增多,脑组织SYN、Ki-67、GFAP、VEGF的表达增多(P<0.05),Nogo-A表达降低(P<0.05),NSE无显著变化(P>0.05),脑梗死体积和胶质瘢痕厚度与PBS组比较无统计学差异(P>0.05)。结论静脉移植BMSCs能改善脑梗死的神经功能,其作用机制可能为促进血管再生和突触重建,增强神经纤维修复和内源性细胞增殖。

Objective To observe the therapeutic bene？ts of intravenously transplanted bone marrow mesenchymal stem cells（BMSCs） on neurological functions of rats after cerebral ischemia.Methods BMSCs were isolated by the differential adhesion,and membrane antigens were detected with flow cytometric analyses.The cerebral ischemia in rats was established with suture emboli method.To evaluate neurological functions,two behavioral tests,the modified neurological severity scores（mNSS） test and the adhesive-removal somatosensory test were performed.The BrdU-labeled BMSCs in vitro and in vivo were detected by the direct immunofluorescence technique.The expression of NSE,Nogo-A,SYN,Ki-67,GFAP and VEGF in the ischemic lesion were defined by immunohistochemistry.Double staining for Bielshowsky silver and Luxol fast blue were adopted to identify axons and myelin,respectively.Results The result of flow cytometry analysis indicated the cells were CD106,CD90,CD29-positive,and CD45,CD34,CD11b-negative.Neurological functions assessed with the mNSS test and adhesive test were significantly improved in BMSCs group compared to PBS Group（P0.05）.The thickness of individual axons and myelin in BMSCs group was significantly increased.The number of SYN,Ki-67,GFAP and VEGF-posive cells was greater in BMSCs group than in PBS group（P0.05）.Nogo-A was fewer in PBS group（P0.05）,however,NSE,the infract volume and the thickness of glial scar were no significant difference between two groups（P0.05）.Conclusions Those results provides a novel therapeutic strategy for improving neurologic function after cerebral ischemia.BMSCs therapy can enhance the endogenous restorative mechanism,angiogenesis,and synaptogenesis,and support the process of axonal reorganization.