人低免疫原性基底前脑胆碱能神经元的获得及其在AD小鼠模型中的应用

Alzheimer’s disease (AD) is the most common form of age-related neurodegenerative disease, characterized by progressive memory loss and cognitive disturbance. The basal forebrain cholinergic neurons (BFCNs) play important roles in the learning and memory ability, and the progressive cholinergic deficiency of BFCNs contributes substantially to the gradual cognitive decline of AD patients. Thus, BFCNs transplantation holds potential in developing stem cell-based replacement therapy for the treatment of AD. To date, various problems, including low efficiency of BFCNs generation and immunogenicity, have limited this strategy to pre-clinical studies. In our previous studies, human embryonic stem cells have been differentiated into BFCNs and we identified four transcription factors can efficiently convert mouse fibroblasts into functional BFCNs. Here, we propose to develop a new approach for induction of high percentage BFCNs from human pluripotent stem cells by overexpressing transcription factors related to BFCNs differentiation. Then, this method will be used to rapidly and efficiently convert HLA knockout pluripotent cells into low immunogenic BFCN progenitors, and the effects of these cells on memory will be evaluated in AD mouse models.

阿尔兹海默病（Alzheimer’s disease, AD）是老年人群中常见的一种神经退行性疾病，临床表现为记忆和认知功能障碍。基底前脑胆碱能神经元（Basal forebrain cholinergic neurons, BFCNs）的功能异常是导致AD病人认知功能障碍的主要原因。因此，BFCNs移植是AD细胞替代治疗的途径之一。人多能干细胞分化得到BFCNs效率低以及免疫排斥等原因阻碍了该细胞的临床应用。本项目前期工作已经建立了将人胚胎干细胞分化为BFCNs的方法，并且筛选得到了四个转录因子能高效转分化鼠成纤维细胞到BFCNs。在此基础上，本项目旨在筛选得到一个能将人多能干细胞快速高效向BFCNs定向分化的方法，然后将此方法应用到HLA复合体敲除的多能干细胞上，从而在体外大量获得高纯度的低免疫原性BFCNs，并将此类神经元的前体细胞移植入AD模型小鼠脑内，考察其对小鼠认知功能的影响。

阿尔兹海默病（Alzheimer’s disease, AD）是老年人群中常见的一种神经退行性疾病，临床表现为记忆和认知功能障碍。神经元的缺失是导致AD病人认知功能障碍的主要原因。细胞替代治疗可能成为治疗AD的方法之一。但是现阶段细胞定向分化效价率低，存活低极大得限制了细胞治疗的应用前景。本项目在人胚胎干细胞谱系追踪、定向分化以及神经干细胞对AD疾病的治疗上做了一些尝试。取得了以下成果：1.一个新的荧光蛋白基因敲入的方法的建立；2.建立了直接诱导人乙酰胆碱神经元的方法；3.诱导得到的神经干细胞显著改善了AD小鼠的学习记忆功能，证明了人神经干细胞对AD治疗的潜在价值。这些成果的获得对AD的细胞治疗有重要的临床前价值，为AD治疗方法的优化提供了基础数据。