GDNF基因修饰神经干细胞移植治疗大鼠帕金森病

Therapeutic effect of GDNF gene-modified mesencephalic neural stem cell transplantation in a rat model of Parkinson disease

目的探讨孕14~15 d胎鼠中脑来源神经干细胞（m NSCs）被胶质源性神经营养因子（GDNF）基因修饰并移植于帕金森病模型大鼠纹状体区的治疗作用。方法取孕14~15 d胎鼠解剖显微镜下分离中脑腹侧组织进行m NSCs培养,培养5 d后行GFP/GDNF基因修饰。PD大鼠模型的建立参照大鼠脑立体定向图谱,立体定向中脑背盖腹侧区、内侧前脑束注射6-羟多巴胺。将PD大鼠随机分组,将基因修饰的干细胞以及无基因修饰干细胞移植到帕金森病大鼠纹状体区,建立空白m NSCs（PBS替代）移植组、GFP基因修饰m NSCs移植组、GDNF基因修饰m NSCs移植组3个实验组。移植细胞前后进行行为学评估,以腹腔注射阿朴吗啡（APO 0.5 mg/kg）诱导PD大鼠旋转圈数作为细胞移植的治疗作用评估手段。免疫荧光组织化学鉴定移植细胞存活、迁移和分化。结果 GDNF基因修饰神经干细胞移植组较对照组和GFP基因修饰神经干细胞移植组有明显的行为改善;移植56 d后,GDNF基因修饰m NSCs移植组较其他两组检测到更多细胞存活,向多巴胺能神经元分化较其他两组都有增加趋势。结论GDNF基因修饰m NSCs移植可显著改善PD大鼠的运动障碍,其分子机制有待进一步研究。

Objective To evaluate the therapeutic effect of transplantation of mesencephalic neural stem cells（m NSCs）genetically modified by glial cell line-derived neurotrophic factor（GDNF） gene in a rat model of Parkinson disease. Methods m NSCs isolated from the lateral component of the midbrain of fetal rats at gestational age of 14 or 15 days were cultured for 5days before genetic modification with GFP or GDNF gene. Rat models of Parkinson disease established by stereotactic injection of 6-hydroxy dopamine in the ventral area of the midbrain and the medial forebrain bundle were randomized into 3groups to receive PBS injection, GFP gene-modified m NSCs transplantation, or GDNF gene-modified m NSCs transplantation into the right stratum. The behavioral changes of the rats were evaluated by observing rotations induced by intraperitoneal injection of apomorphine after the transplantation, and the survival, migration and differentiation of the transplanted cells were identified by immunohistochemistry. Results Transplantation with GDNF gene-modified m NSCs significantly improved the behavioral abnormalities of the rat models as compared with PBS injection and GFP gene- modified m NSCs transplantation. At 56 days after the transplantation, a greater number of the transplanted cells survived in the rat brain and more differentiated dopaminergic neurons were detected in GDNF gene-modified m NSCs transplantation group than in GFP gene- modified m NSCs transplantation group. Conclusion GDNF gene- modified m NSCs transplantation can significantly improve dyskinesia in rat models of Parkinson disease, but the molecular mechanism needs further clarification.