College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Chungbuk, Republic of Korea.
Department of Biology Education, Korea National University of Education, Cheongju 28173, Chungbuk, Republic of Korea.
Int J Mol Sci. 2023 May 31;24(11):9561. doi: 10.3390/ijms24119561.
Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. In AD patients, amyloid-β (Aβ) peptide-mediated degeneration of the cholinergic system utilizing acetylcholine (ACh) for memory acquisition is observed. Since AD therapy using acetylcholinesterase (AChE) inhibitors are only palliative for memory deficits without reversing disease progress, there is a need for effective therapies, and cell-based therapeutic approaches should fulfil this requirement. We established F3.ChAT human neural stem cells (NSCs) encoding the choline acetyltransferase (ChAT) gene, an ACh-synthesizing enzyme, HMO6.NEP human microglial cells encoding the neprilysin (NEP) gene, an Aβ-degrading enzyme, and HMO6.SRA cells encoding the scavenger receptor A (SRA) gene, an Aβ-uptaking receptor. For the efficacy evaluation of the cells, first, we established an appropriate animal model based on Aβ accumulation and cognitive dysfunction. Among various AD models, intracerebroventricular (ICV) injection of ethylcholine mustard azirinium ion (AF64A) induced the most severe Aβ accumulation and memory dysfunction. Established NSCs and HMO6 cells were transplanted ICV to mice showing memory loss induced by AF64A challenge, and brain Aβ accumulation, ACh concentration and cognitive function were analyzed. All the transplanted F3.ChAT, HMO6.NEP and HMO6.SRA cells were found to survive up to 4 weeks in the mouse brain and expressed their functional genes. Combinational treatment with the NSCs (F3.ChAT) and microglial cells encoding each functional gene (HMO6.NEP or HMO6.SRA) synergistically restored the learning and memory function of AF64A-challenged mice by eliminating Aβ deposits and recovering ACh level. The cells also attenuated inflammatory astrocytic (glial fibrillary acidic protein) response by reducing Aβ accumulation. Taken together, it is expected that NSCs and microglial cells over-expressing ChAT, NEP or SRA genes could be strategies for replacement cell therapy of AD.
阿尔茨海默病（AD）是最常见的神经退行性疾病之一。在 AD 患者中，观察到淀粉样β（Aβ）肽介导的利用乙酰胆碱（ACh）进行记忆获取的胆碱能系统退化。由于使用乙酰胆碱酯酶（AChE）抑制剂的 AD 治疗仅对记忆缺陷有缓解作用，而不能逆转疾病进展，因此需要有效的治疗方法，细胞为基础的治疗方法应该满足这一要求。我们建立了 F3.ChAT 人神经干细胞（NSC），其编码胆碱乙酰转移酶（ChAT）基因，这是一种合成 ACh 的酶，HMO6.NEP 人小胶质细胞编码神经肽酶（NEP）基因，这是一种 Aβ 降解酶，以及 HMO6.SRA 细胞编码清道夫受体 A（SRA）基因，这是一种 Aβ 摄取受体。为了评估细胞的疗效，我们首先根据 Aβ 积累和认知功能障碍建立了合适的动物模型。在各种 AD 模型中，脑室内（ICV）注射乙基胆碱 mustard 氮离子（AF64A）诱导最严重的 Aβ 积累和记忆功能障碍。将建立的 NSCs 和 HMO6 细胞移植到 ICV 到因 AF64A 挑战而导致记忆丧失的小鼠中，分析大脑 Aβ 积累、ACh 浓度和认知功能。所有移植的 F3.ChAT、HMO6.NEP 和 HMO6.SRA 细胞都在小鼠大脑中存活了 4 周，并且表达了它们的功能性基因。NSCs（F3.ChAT）与编码每种功能性基因（HMO6.NEP 或 HMO6.SRA）的小胶质细胞的联合治疗通过消除 Aβ 沉积和恢复 ACh 水平，协同恢复了 AF64A 挑战小鼠的学习和记忆功能。这些细胞还通过减少 Aβ 积累来减轻炎症星形胶质细胞（胶质纤维酸性蛋白）反应。总之，预计过表达 ChAT、NEP 或 SRA 基因的 NSCs 和小胶质细胞可以作为 AD 替代细胞治疗的策略。
