黄芪甲苷调控SHH-Nurr1通路促进帕金森大鼠神经干细胞向多巴胺能神经元分化的研究

Parkinson’s disease (PD) is a central nervous system degenerative disease characterized by the lack of dopamine function in the substantia nigra-striatum (SNS) system in the elderly. Neural stem cells (NSCs) are pluripotent stem cells that have the ability to self-replicate and differentiate into neurons, astrocytes and oligodendrocytes under certain conditions, and have the potential to differentiate into dopaminergic (DA) neurons. In our preliminary study, we found that astragaloside was able to promote the proliferation of NSCs and differentiate into DA neurons, and up-regulate the expression of SHH and Nurr1 mRNA. In order to clarify the effect of astragaloside on the differentiation of NSCs into DA neurons and reveal its underlying mechanism, we design the following project. Firstly, the proliferation and apoptosis of NSCs, and the differentiated phenotype of DA neurons are detected in vitro and in vivo experiments. Then, with specific siRNA-mediated SHH/Nurr1 down-regulation of NSCs, DA neurons' phenotype and SHH/Nurr1 are examined to investigate whether astragaloside induced NSCs to differentiate into DA neurons by regulating SHH-Nurr1 pathway, thus providing a basis for the treatment of Parkinson's disease with astragaloside.

帕金森病是老年人常见的以黑质-纹状体系统多巴胺功能不足为主要特征的中枢神经系统退行性疾病。而神经干细胞（Neural stem cells，NSCs）是一种可以自我复制，并能够分化为神经元、星形胶质细胞和少突胶质细胞的多功能干细胞，具有分化为多巴胺能神经元的潜能。我们前期初步通过体外研究，发现黄芪甲苷可以促进NSCs增殖和向多巴胺能神经元分化，并可上调分化相关因子SHH、Nurr1 mRNA的表达。为了明确黄芪甲苷对NSCs向多巴胺能神经元定向分化的作用及揭示其潜在机制，本次研究方案如下：首先通过体内外实验，检测NSCs增殖、凋亡和多巴胺能神经元分化表型，然后在特异siRNA介导的SHH/Nurr1基因下调的NSCs中，检测黄芪甲苷对多巴胺能神经元表型转化作用，从而研究黄芪甲苷是否通过调节SHH-Nurr1通路诱导NSCs向多巴胺能神经元分化，从而为黄芪甲苷治疗帕金森病提供依据。

帕金森病是老年人常见的以黑质-纹状体系统多巴胺功能不足为主要特征的中枢神经系统 退行性疾病。而神经干细胞（Neural stem cells，NSCs）是一种可以自我复制，并能够分化为神经元、星形胶质细胞和少突胶质细胞的多功能干细胞，具有分化为多巴胺能神经元的潜 能。我们前期初步通过体外研究，发现黄芪甲苷可以促进NSCs增殖和向多巴胺能神经元分化，并可上调分化相关因子SHH、Nurr1 mRNA的表达。为了明确黄芪甲苷对NSCs向多巴胺能神经元定向分化的作用及揭示其潜在机制，首先通过体内外实验，检测NSCs增殖和多巴胺能神经元分化表型，然后在特异siRNA介导的SHH/Nurr1基因下调的NSCs中，检测黄芪甲苷对多巴胺能神经元表型转化作用，从而研究黄芪甲苷是否通过调节SHH-Nurr1通路诱导NSCs向多巴胺能神经元分化，从而为黄芪甲苷治疗帕金森病提供依据。研究发现黄芪甲苷可以改善帕金森大鼠的行为学，以第28天更为明显；黄芪甲苷干预PD大鼠后，脑组织NSCs增殖标志物PCNA、神经元表型标志物Tuj-1及DA神经元标志物TH的表达均较模型组增高。黄芪甲苷体外干预NSCs后，NSCs增殖标志物EdU、神经元表型标志物Tuj-1及DA神经元标志物TH的表达均较正常组增高，因此证明黄芪甲苷可以促进NSCs增殖及向DA神经元分化。NSCs体外培养，siRNA SHH组Nurr1、TH和DAT的表达均下降；而加入黄芪甲苷后，Nurr1、TH和DAT的表达有所增加。因此证明黄芪甲苷可以调节SHH-Nurr1通路促进NSCs向DA神经元分化。