Molecular genetic analyses of transcriptional dysregulation in Alzheimers disease

项目摘要/摘要 最近，多项人类遗传学研究已经确定了免疫系统在疾病中的关键作用。 阿尔茨海默病(AD)的发病机制。例如，小胶质细胞吞噬淀粉样β蛋白(Abeta)和 通过分泌细胞因子和趋化因子来调节大脑免疫功能。因为之前的研究已经 提示阿尔茨海默病中小胶质细胞活动既有保护作用，也有有害作用，小胶质细胞活动对AD的危险基因，如 作为PU.1，对小胶质细胞功能的影响仍不清楚。因此，研究阿尔茨海默病遗传危险因素的作用 将提供对该病病理生物学的关键洞察，潜在地揭示关键的调控因素 潜在的疾病机制和新的治疗靶点。AD的遗传风险因素PU.1是一个关键因素 转录因子选择性表达于脑内的小胶质细胞。我们假设PU1会影响几个 转录途径、Abeta代谢和其他与AD相关的病理通过调节其免疫功能。 为了验证这一假设，我们将应用几项创新技术，包括单细胞RNA测序， 定量蛋白质组学，超分辨显微镜，人类诱导的多能干细胞来源的小胶质细胞 和神经元，多电极阵列，电生理学，和同步正电子发射断层扫描- 磁共振成像，由在这些领域拥有丰富经验的多个合作者合作 方法：研究方法。在目标1中，我们将确定下调PU1如何影响小胶质细胞和神经元的表型和 进行无偏见的转录和蛋白质组学分析，以确定关键的下游调控因子。在目标2中，我们将 利用人诱导多能干细胞研究小胶质细胞与神经元之间的功能相互作用 在调控PU.1表达后，PU1的表达受到抑制。在目标3中，我们将终止小胶质细胞PU1是如何影响AD表型的 在淀粉样变发病前后受到调节。

Project Summary/Abstract Recently, multiple human genetic studies have identified the critical role of the immune system in the pathogenesis of Alzheimer’s disease (AD). For example, microglia phagocytose amyloid beta (Abeta) and regulate brain immune function by secreting cytokines and chemokines. Because previous studies have suggested both protective and detrimental effects of microglial activity in AD, how microglial AD risk genes, such as PU.1, affect microglial function still remains unclear. Therefore, investigating the role of AD genetic risk factors in microglia will provide critical insight into the pathobiology of the disease, potentially revealing key regulators of underlying disease mechanisms and novel therapeutic targets. An AD genetic risk factor, PU.1, is a critical transcription factor selectively expressed in microglia in the brain. We hypothesize that PU.1 affects several transcription pathways, Abeta metabolism and other AD-related pathologies by regulating their immune function. To test this hypothesis, we will apply several innovative technologies, including single-cell RNA-sequencing, quantitative proteomics, super-resolution microscopy, human-induced pluripotent stem cell-derived microglia and neurons, multi-electrode arrays, electrophysiology, and the simultaneous Positron Emission Tomography- Magnetic Resonance Imaging, in collaboration of multiple collaborators with extensive experience in these methods. In aim 1, we will determine how downregulating PU.1 affects microglial and neuronal phenotypes and perform unbiased transcriptomic and proteomic analyses to identify key downstream regulators. In aim 2, we will investigate the functional interaction between microglia and neurons using human induced pluripotent stem cells after regulating PU.1 expression. In aim 3, we will terminate how microglial PU.1 affects AD phenotypes when it is regulated before and after the onset of amyloid pathology.