骨髓基质多能成体祖细胞在帕金森病大鼠体内移植与多巴胺能神经元分化的研究

Bone marrow multipotent adult progenitor cells develop into functional dopaminergic neurons after transplantation in Parkinson rat models

目的探讨骨髓基质分离的多能成体祖细胞(MAPCs)通过系统移植(即尾静脉注射)方式进入大鼠脑组织内并修复受损的神经功能。方法制作实验性帕金森病大鼠模型,将在体外纯化、增殖和已用5-溴-2脱氧尿苷(BrdUrd)处理过的MAPCs通过尾静脉注入帕金森病大鼠体内。3个月后,对移植大鼠采用免疫组化技术、RT-PCR、免疫电镜、行为学评定等方法鉴定移行入大鼠脑组织内的MAPCs、其分化的神经元样细胞以及神经功能的修复。结果MAPCs能移行入大鼠脑组织内并在中脑黑质和纹状体区分化为神经元样细胞;6-羟多巴诱导的大鼠行为损伤有明显恢复;多巴胺-β-羟化酶、神经生长因子和多巴胺转运体mRNA的表达水平明显升高;电镜下观察到MAPCs所分化的神经细胞与其它神经细胞形成突触联系;这些资料表明MAPCs能在大鼠脑组织内分化为多巴胺能神经细胞并发挥相应的神经功能。结论骨髓基质分离的MAPCs能通过系统移植方式进入大鼠脑组织内,在中脑微环境中可自主分化为多巴胺能神经细胞并有效地修复6-羟多巴诱导的神经功能缺损。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-multipotent adult progenitor cells (MAPCs) enter the brain and reduce neurological functional deficits in rats by injecting intravenously. Methods We established successfully animal models of parkinson’s disease in rats,sequentially,we injected MAPCs by tail vein. For cellular identification,MAPCs were prelabeled with bromodeoxyuridine(BrdUrd). By three months of postinjection,behavioral tests,immunofluorescence method,RT-PCR and electron microscopy was used to identify MAPCs or neuron-like cells derived from MAPCs in brain. Results After implantation,MAPCs could survive and differentiate into neuron-like cells in substantia nigra and striatum,including into dopaminergic-neurons. Compared with control animals,MAPCs-derived dopaminergic neurons caused gradual and sustained behavioral restoration of 6-OHDA-mediated motor asymmetry. Levels of DBH,NGF and DAT mRNA were upregulated significantly,which suggested MAPCs-derived neurons could performed the function of dopaminergic neurons. The finding of immature synapse implicated MAPCs-derived neurons should have an important role in reconstruction of neural circuitry. Conclusion These results demonstrate that transplanted MAPCs can develop spontaneously into dopaminergic neurons. Such dopaminergic neurons can restore cerebral function and behavior in rat models of Parkinson’s disease. MAPCs may provide a powerful autoplastic therapy for a variety of central nervous system disorders.