大鼠骨髓间质多能成体祖细胞系统移植治疗脑缺血性损伤的研究

Bone marrow multipotent adult progenitor cells develop into functional neurons after transplantation in cerebral ischemic rat models

目的探讨骨髓间质分离的多能成体祖细胞(MAPCs),通过系统移植方式(尾静脉注入)进入大鼠脑组织内及修复受损的神经功能。方法采用改良Nagasaway与Zea Longa等线栓法建立大鼠脑缺血再灌注模型,并将大鼠随机分为对照组(n=40)和MAPCs组(n=40)。将在体外纯化、增殖和已用5-溴脱氧尿苷(BrdU)处理过的MAPCs经尾静脉注射入大鼠体内。采用行为学评定、免疫荧光技术、RT-PCR和免疫电镜等方法识别移行入大鼠脑组织内的MAPCs分化的神经元样细胞及其功能表达。结果(1)MAPCs能移行入大鼠脑组织内并在大脑中动脉阻断(MCAO)的同侧海马区分化为神经元样细胞,免疫荧光双重标记染色显示BrdU、神经元特异性烯醇化酶(NSE)表达阳性;(2)与对照组比较,在MAPCs移植组(MAPCs组),MCAO所致的大鼠行为损伤明显恢复,神经生长因子(NGF)表达水平明显升高(P<0.05);(3)电镜下观察到MAPCs所分化的神经样细胞与其它神经细胞形成突触联系。结论MAPCs能经血液途径进入脑缺血灶微环境中,分化为神经样细胞并有效地修复大鼠MCAO所致的神经功能缺失症状。因此,MAPCs有望成为中枢神经系统疾病自体移植治疗的最佳候选干细胞之一。

Objective We tested the hypothesis that bone marrow derived-muhipotent adult progenitor cells （MAPCs）enter the cerebral and reduce neurological functional deficits in cerebral ischemic rats by injecting intravenously. Methods We established successfully cerebral ischemic rats models by Nagasawa and Zea Longa improvement method,sequentially,we injected MAPCs from tail vein,for cellular identification,MAPCs were prelabeled with bromodeoxyuridine （BrdU）. Behavioral tests,immunofluorescence methods,RT-PCR and electron microscopy were used to identify neuron-like cells derived from MAPCs in brain and their functions. Results （1）After implantation,MAPCs could survive and differentiate into neuron-like cells in hippocampus. （2）Compared with control animals,MAPCs-derived neurons caused gradual and sustained MCAO-induced behavioral restoration. Levels of NGF mRNA was upregulated significantly. （3）The finding of immature synapse implicated MAPCs-derived neuron should have an important role in reconstruction of neural circuitry. Conclusions These results demonstrate that transplanted MAPCs can develop spontaneously into neurons. Such neurons can restore cerebral function in cerebral ischemic rat models. MAPCs may provide a powerful autoplastic therapy for a variety of central nervous system disorders.