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

项目摘要 阿尔茨海默病（AD）是老年人中最常见的痴呆症，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， 为这种疾病开发有效的治疗方法。已经产生了许多用于AD研究的小鼠模型， 这些模型提供了重要的见解，有助于我们了解疾病的病理基础。 然而，由于小鼠和人类神经细胞之间存在显着的物种差异， 需要人类疾病建模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2000年以来已广泛用于疾病建模。 iPSC技术的发展。hiPSC已用于模拟AD的各个方面。因为hiPSC 和它们的衍生物被认为是表型年轻的，hiPSC衍生的细胞已被用于建模， AD的早期事件。直接重编程是另一种类型的重编程，它将一种类型的体细胞重编程转化为另一种类型的体细胞重编程。 细胞转化为另一个细胞，而不需要经过涉及广泛表观遗传修饰的iPSC阶段， 从而能够产生具有细胞老化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允许我们模拟AD的年龄相关病理。 ApoE 4是最强的，CLU rs 11136000 SNP的C等位基因是第三强的遗传风险因素 对于AD。本提案的目的是确定CLU rs 11136000 SNP单独或与 ApoE 4对AD风险的影响，并揭示该效应背后的分子和细胞机制，使用人类 从hiPSC或通过直接重编程产生的细胞模型。我们将使用基因编辑的同基因细胞 以确定CLU SNP与ApoE同种型组合的作用。此外，由于hiPSC衍生的细胞和 来自相同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，它们代表了同基因细胞平台，使我们能够专门研究 细胞老化的迹象这些同基因模型将使我们能够概括年龄相关的表型， AD的新病理机制。因为CLU和ApoE都在星形胶质细胞中高度表达， 我们建议使用星形胶质细胞来确定CLU SNP单独或与ApoE一起的作用。我们假设 CLU以ApoE亚型和年龄依赖性方式调节AD病理。所以我们提出 目的1：获得具有不同APOE/CLU基因型和细胞老化的星形胶质细胞 从hiPSC或通过直接重编程的状态。目的2：确定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。目的3：确定 APOE/CLU基因型与人脑衰老及基因表达变化拟议的研究将有助于 确定CLU SNP在年龄相关AD病理发展中的作用， 研究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.