Investigation of the role of glia cells in Alzheimers pathogenesis in a functional human-based in vitro model

科学摘要/摘要 阿尔茨海默病(AD)是最常见的神经退行性疾病，其特点是进行性 导致与年龄相关的痴呆症的认知衰退。这五种被批准的药物只提供了适度的 对症状有好处，在阻止疾病进展方面效果不大。改进机械结构 了解疾病的发生和发展对于开发有效的阿尔茨海默病药物至关重要。几十年的努力 通过靶向淀粉样β蛋白(Aβ)和Tau病理，专注于“以神经元为中心”的机制。最近 神经炎症作为AD病因学中的一个活跃成分，已得到越来越多的认识。它是 成为破解中枢神经系统中主要参与者星形胶质细胞和小胶质细胞激活机制的关键 神经炎症及其在AD病理过程中与神经元的相互作用。然而，神经胶质细胞的机制 对神经元的激活及其与神经元的相互作用知之甚少，特别是在人类中，这是因为缺乏适当的 模特们。这项研究致力于开发一种以人为本的功能系统，使机械学研究成为可能 关于神经元-神经胶质细胞的相互作用，利用诱导多能干细胞的进展 电池(IPSC)和生物MEMS(微电子机械系统)技术。具体目标是：1)调查 定量研究阿尔茨海默病患者皮层神经元在模式化MEA上的功能缺陷 诱发长时程增强(LTP)的波幅、维持及功能 突触，与来自健康受试者的皮质神经元相比。中国经济发展的纵向进程 表型也将被分析。表达家族性AD基因的AD-皮质神经元的整合可能揭示 这些神经元的自体功能表型。2)构建以人为本的三种文化模式 由人IPSC来源的皮质神经元、星形胶质细胞和小胶质细胞组成，以研究神经元- 阿尔茨海默病中胶质细胞的相互作用。胶质细胞对AD神经元功能和激活状态的影响 将对三代培养中的神经胶质细胞进行检测。这一结果将有助于阐明星形胶质细胞和小胶质细胞是否仍然 在AD神经元存在的情况下具有保护作用，或者在病理过程中的某个时间点变得有毒。 IPSC来源的功能使特定于患者的建模成为可能。非侵入性MEA系统 允许按时间顺序监测神经回路功能，这对于研究与衰老相关的疾病至关重要。 功能读数、长时程增强(LTP)和突触数量已被证明模拟一些临床 认知缺陷。该模型为研究卵巢癌的早期病理和进展提供了理想的平台。 阿尔茨海默病神经元功能损害及其与胶质细胞的相互作用。该模型的应用可以揭示 神经胶质细胞激活的基本机制及其与神经元的相互作用，并揭示潜在的治疗靶点 对于AD。平台和病因学的发现都可以加速有效治疗的发展 对于AD。

Scientific Abstract / Summary Alzheimer’s disease (AD) is the most prevalent neurodegenerative disorder characterized by progressive cognitive decline that leads to age-related dementia. The five approved medications provide only modest symptomatic benefits and provide little effect in halting the disease progression. Improving the mechanistic understanding of disease onset and progression is essential for developing effective AD drugs. Decades of effort have focused on “neuron-centric” mechanisms by targeting amyloid beta (Aβ) and Tau pathologies. Recently neuroinflammation has gained increasing recognition as being an active component in AD etiology. It is becoming crucial to decipher the activation mechanism of astrocytes and microglia, the major players in CNS neuroinflammation, and their interactions with neurons during AD pathology. However, the mechanisms of glial activation and their interplay with neurons is poorly understood, especially in humans, due to the lack of proper models. This study endeavors to develop a human-based functional system that enables the mechanistic study concerning neuron-glia interactions, by taking the advantage of the progress made in induced pluripotent stem cell (iPSC) and Bio-MEMs (microelectromechanical systems) technology. The Specific Aims are: 1) Investigate the functional deficits of cortical neurons derived from AD patients on patterned MEAs, by quantifying the amplitude and maintenance of induced long term potentiation (LTP) and the number of functional synapses, compared to cortical neurons derived from healthy subjects. The longitudinal progression of the phenotype will also be analyzed. Integration of AD-cortical neurons expressing a familial AD gene could uncover the autologous functional phenotype in these neurons. 2) Develop a human-based tri-culture model consisting of human iPSC-derived cortical neurons, astrocytes and microglia, to investigate the neuron- glia interaction in AD. Both the effect of glial cells on the functionality of AD-neurons and the activation status of glia in the tri-culture will be examined. The results will help clarify whether astrocytes and microglia are still protective in the presence of AD-neurons, or becoming toxic at a certain point during the pathological process. The iPSC-sourced feature enables the possibility of patient-specific modeling. The non-invasive MEA system allows chronological monitoring of neural circuit function which is critical to investigate aging-related diseases. Functional readouts, long-term potentiation (LTP) and synapse number have been shown to imitate some clinical cognitive deficits. The model provides an ideal platform for investigating the early pathology and progression of functional impairment of AD-neurons and their interactions with glia. Application of this model could uncover essential mechanisms of glial activation, their interaction with neurons, and reveal potential therapeutic targets for AD. Both the platform and the etiological discoveries could accelerate the development of effective treatments for AD.