帕金森病小鼠的内源性神经再生修复研究

发布时间：2019-06-21 12:44

【摘要】：第一部分：基于全转录组深度测序的MPTP小鼠室管膜下区和齿状回神经再生相关基因表达分析成年动物中枢神经系统的功能稳定和组织修复依赖于室管膜下区(subventricular zone, SVZ)和齿状回(dentate gyrus, DG)的神经再生。多巴胺(dopamine, DA)能够调控这些区域内源性神经干细胞(neural stem cells, NSCs)参与神经再生修复,但其缺乏却影响神经再生。值得注意的是,导致脑内DA不足的帕金森病(Parkinson's disease, PD)对神经再生的影响还不明确。我们提取腹腔注射MPTP小鼠的SVZ和DG组织进行转录组测序。结果分析发现,差异表达的基因集中注释于转录调节、免疫反应、细胞外基质、细胞连接和髓鞘形成等功能。这些基因部分显示出表达水平的时间依赖性,部分参与神经再生相关的能量代谢变化。除此以外,MAPK信号通路在SVZ被激活,却在DG受到负性调控。因此我们认为,MPTP注射的帕金森病动物,其SVZ和DG表现出不同的转录组水平改变。第二部分：移植人神经干细胞促进帕金森病小鼠内源性神经再生修复帕金森病(Parkinson's disease, PD)是最常见的神经退行性疾病之一,以黑质(substantia nigra, SN)多巴胺能神经元大量死亡和纹状体(striatum, Str)严重缺乏多巴胺(dopamine, DA)为主要特征。然而疾病治疗仍面临诸多挑战。近年来神经干细胞(neural stem cells, NSCs)颅内移植被认为是中枢神经系统退行性疾病的有效治疗手段,但其对症状改善的潜在机制仍不十分明确。本研究通过在腹腔注射MPTP的小鼠纹状体内立体定向移植人神经干细胞(human neural stem cells, hNSCs),观察评估其在PD疾病状态下动员和激活内源性细胞并改善细胞微环境以发挥神经保护作用的能力。与对照组相比,hNSCs移植组小鼠行为学恢复显著,SN多巴胺能神经元数量明显增多,差异有统计学意义(p0.05)。移植入纹状体的hNSCs存活、增殖、分化,并沿星型胶质细胞形成的鞘管样结构迁移。值得注意的是,hNSCs移植小鼠的纹状体内出现了大量内源性去分化的星型胶质细胞。这些星型胶质细胞具有原始的NSCs或神经前体细胞(neural precursor cells, NPCs)特性,在局部分泌大量神经营养因子。除此以外,hNSCs移植组纹状体和SN的小胶质细胞数量较对照组明显减少,且促炎因子水平显著降低,差异具有统计学意义(p0.05)。总体而言,纹状体内立体定位移植hNSCs可促进MPTP小鼠神经功能恢复,这可能与移植物调节改善宿主微环境以促进内源性神经再生相关。进一步研究移植细胞自身增殖分化迁移及其改善宿主微环境的能力有助于优化PD的细胞治疗。
[Abstract]:Part 1: gene expression analysis of subependymal area and dentate gyrus nerve regeneration in MPTP mice based on deep sequencing of full transcription group functional stability and tissue repair of central nervous system in adult animals depend on (subventricular zone, SVZ) in subependymal area and nerve regeneration in dentate gyrus. Dopamine (dopamine, DA) can regulate (neural stem cells, NSCs) in these areas to participate in nerve regeneration and repair, but its lack affects nerve regeneration. It is worth noting that the effect of (Parkinson's disease, PD) on nerve regeneration in Parkinson's disease, which leads to DA deficiency in the brain, is not clear. The SVZ and DG tissues of MPTP mice were extracted and sequenced. Results it was found that the differentially expressed genes focused on transcriptional regulation, immune response, extracellular matrix, cell junction and myelin sheath formation. Some of these genes show a time-dependent expression level, and some of them are involved in the changes of energy metabolism related to nerve regeneration. In addition, MAPK signaling pathway is activated in SVZ, but negatively regulated in DG. Therefore, we believe that the levels of SVZ and DG in Parkinson's disease animals injected with MPTP showed different changes in transcriptional group. The second part: transplantation of human neural stem cells to promote endogenous nerve regeneration in Parkinson's disease mice to repair Parkinson's disease (Parkinson's disease, PD) is one of the most common neurodegenerative diseases, characterized by the death of a large number of (substantia nigra, SN) dopaminergic neurons in substantia nigra and the severe lack of dopamine (dopamine, DA) in striatum (striatum, Str). However, disease treatment still faces many challenges. In recent years, neural stem cell (neural stem cells, NSCs) intracranial transplantation is considered to be an effective treatment for central nervous system degenerative diseases, but its potential mechanism for symptom improvement is still not very clear. The aim of this study was to evaluate the ability of stereotactic transplantation of human neural stem cells (human neural stem cells, hNSCs),) into striatum of mice injected with MPTP to mobilize and activate endogenous cells and improve cell microenvironment to play a neuroprotective role in the state of PD disease. Compared with the control group, the behavior of mice in hNSCs transplantation group recovered significantly, and the number of SN dopaminergic neurons increased significantly (p0.05). The hNSCs transferred into striatum survived, proliferated, differentiated and migrated along the sheath-like structure formed by starlike glial cells. It is worth noting that a large number of endogenously dedifferentiated star glial cells appeared in the striatum of hNSCs transplantation mice. These star glial cells have the characteristics of primitive NSCs or neural precursor cell (neural precursor cells, NPCs), and secrete a large number of neurotrophic factors locally. In addition, the number of microglia in striatum and SN in hNSCs transplantation group was significantly lower than that in control group, and the level of pro-inflammatory factor was significantly lower than that in control group (p0.05). In general, stereotactic transplantation of hNSCs in striatum can promote the recovery of nerve function in MPTP mice, which may be related to the regulation of graft to improve the host microenvironment to promote endogenous nerve regeneration. Further study on the proliferation, differentiation and migration of transplantation cells and the ability to improve the host microenvironment are helpful to optimize the cell therapy of PD.
【学位授予单位】：北京协和医学院
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R742.5

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