Define the effect of CLU SNP on the risk to Alzheimer's disease

项目概要 阿尔茨海默病 (AD) 是老年人最常见的痴呆症，目前尚无治愈方法 疾病。 AD发病机制的分子和细胞机制仍有待阐明 开发针对这种疾病的有效疗法。已经建立了许多用于 AD 研究的小鼠模型 这些模型为帮助我们了解该疾病的病理基础提供了重要的见解。 然而，由于小鼠和人类神经细胞之间存在显着的物种差异，因此建立 需要人类疾病模型平台来补充动物模型研究，以更好地了解 AD。 人类诱导多能干细胞（hiPSC）自诞生以来已广泛用于疾病建模 iPSC技术的发展。 hiPSC 已被用于模拟 AD 的各个方面。因为 hiPSC 及其衍生物被认为表型年轻，hiPSC 衍生细胞已被用于建模 AD的早期事件。直接重编程是另一种类型的重编程，可将一种类型的体细胞转化为 细胞无需经过涉及广泛表观遗传修饰的 iPSC 阶段即可转移到另一个细胞，因此 能够产生具有细胞衰老关键要素的人类细胞。因此，直接 来自患者体细胞的重编程细胞将使我们能够模拟与年龄相关的 AD 病理。 ApoE4 最强，CLU rs11136000 SNP 的 C 等位基因是第三强的遗传风险因素 对于AD。该提案的目的是确定 CLU rs11136000 SNP 单独或与 ApoE4 对 AD 风险的影响并揭示了该效应背后的分子和细胞机制，利用人类 由 hiPSC 或通过直接重编程生成的细胞模型。我们将使用基因编辑的同基因细胞 定义 CLU SNP 与 ApoE 同工型结合的效果。此外，由于 hiPSC 衍生的细胞和 来自同一供体的直接重编程细胞具有相同的遗传背景但不同 细胞衰老状态，它们代表同基因细胞平台，使我们能够专门研究其影响 细胞老化。这些同基因模型将使我们能够概括与年龄相关的表型并揭示 AD 背后的新病理机制。由于CLU和ApoE在星形胶质细胞中高表达， 我们建议使用星形胶质细胞单独或与 ApoE 一起定义 CLU SNP 的效果。我们假设 CLU 以 ApoE 同工型和年龄依赖性方式调节 AD 病理。因此，我们建议 具体目标如下： 目标 1：衍生具有不同 APOE/CLU 基因型和细胞老化的星形胶质细胞 来自 hiPSC 或通过直接重编程的状态。目标 2：定义 APOE 和 CLU 变体对 使用星形胶质细胞-神经元或星形胶质细胞-OPC 共培养物的 AD 发病机制。目标 3：确定以下关系 APOE/CLU 基因型和衰老与人脑基因表达变化。拟议的研究将有助于 定义 CLU SNP 在与年龄相关的 AD 病理发展中的作用，揭示 AD发病机制，并设计新的AD治疗策略。

Project Summary Alzheimer’s disease (AD) is the most common form of dementia in the elderly and there is no cure for this disease. The molecular and cellular mechanisms underlying AD pathogenesis remains to be elucidated to develop effective therapies for this disease. Many mouse models have been generated for AD research and these models provide important insights to aid our understanding of the pathological basis of the disease. However, because there are significant species differences between mouse and human neural cells, establishing human disease modeling platforms is needed to complement studies in animal models to better understand AD. Human induced pluripotent stem cells (hiPSCs) have been widely used for disease modeling since the development of the iPSC technology. hiPSCs have been used to model various aspects of AD. Because hiPSCs and their derivatives have been considered phenotypically young, hiPSC-derived cells have been used to model early events of AD. Direct reprogramming is another type of reprogramming that converts one type of somatic cells into another without going through the iPSC stage that involves extensive epigenetic modifications, thus enabling generation of human cells that possess key elements of cellular aging. Therefore, directly reprogrammed cells derived from patient somatic cells would allow us to model age-related pathologies of AD. ApoE4 is the strongest and the C allele of the CLU rs11136000 SNP is the third strongest genetic risk factor for AD. The objective of this proposal is to define the effect of the CLU rs11136000 SNP alone or together with ApoE4 on the risk to AD and uncover molecular and cellular mechanisms underlying the effect, using human cellular models generated from hiPSCs or through direct reprogramming. We will use gene-edited isogenic cells to define the effect of CLU SNP in combination with ApoE isoform. In addition, because hiPSC-derived cells and directly reprogrammed cells derived from the same donors have the same genetic background but different cellular aging status, they represent isogenic cellular platforms that will enable us to specifically study the effect of cellular aging. These isogenic models will allow us to recapitulate age-associated phenotypes and uncover novel pathological mechanisms underlying AD. Because both CLU and ApoE are highly expressed in astrocytes, we propose to define the effect of the CLU SNP alone or together with ApoE using astrocytes. We hypothesize that CLU modulates AD pathologies in an ApoE isoform- and age-dependent manner. Therefore, we propose following Specific Aims: Aim 1: To derive astrocytes with different APOE/CLU genotypes and cellular aging status from hiPSCs or through direct reprogramming. Aim 2: To define the effect of APOE and CLU variants on AD pathogenesis using astrocyte-neuron or astrocyte-OPC co-cultures. Aim 3: To determine the relationship of APOE/CLU genotypes and aging with gene expression change in human brains. The proposed studies will help to define the roles of the CLU SNP in the development of age-associated AD pathologies, to uncover mechanisms underlying AD pathogenesis, and to design novel therapeutic strategies for AD.