The impact of AD-associated genetic variants in 3D human mixed neural-glial models of AD

标题：AD相关遗传变异对AD 3D人类混合神经胶质模型的影响 项目摘要 越来越多的阿尔茨海默病（AD）相关基因与先天免疫有关， 神经炎症通路。基于网络的AD相关基因整合分析表明， 小胶质细胞基因网络与AD神经病理学密切相关（1，5）。我们已经证明， 保护性AD相关的CD 33变体rs3865444导致CD 33表达降低， Aβ42）（1）。相反，增加AD风险的小胶质细胞TREM 2变体减少Ab的小胶质细胞清除。在 除了CD 33和TREM 2中的AD相关功能变体外，我们的AD全基因组测序（WGS）和 来自AD家族和病例对照的全外显子组测序（WES）数据集，已经揭示了AD家族和病例对照的功能性基因表达。 与先天免疫和神经炎症相关的AD相关小胶质细胞基因的变体，包括CD 33， TREM 2、MS 4A簇、ABCA 7、ABI 3、PLGC 2、CR 1等。为了测试小胶质细胞遗传的影响， 在人类遗传背景下，我们开发了一种新的3D人类神经元， 星形胶质细胞-小胶质细胞三培养AD模型使用独特的3D微流体系统。我们证明了人类 小胶质细胞通过小胶质细胞特异性免疫反应被募集到3D AD（产生Ab）神经元-星形胶质细胞培养物中。 迁移通道，以趋化因子依赖的方式，导致神经炎症和神经变性。 在这里，我们建议使用我们广泛收集的AD WGS和WES数据集，以及我们的3D人体模型。 三培养AD模型，以评估AD相关先天免疫中功能变体的致病作用。 与神经炎症有关的基因在目标1中，我们将鉴定功能性基因组变体和富集的基因， 与先天免疫和神经炎症有关的网络。然后我们将研究致病作用 小胶质细胞AD风险或保护基因及其功能变体在3D人类混合神经-星形胶质细胞- AD的小胶质细胞模型（目的2），探索与小胶质细胞AD风险基因相关的AD致病途径 及其功能变体，并验证选择性地阻断这些功能变体。 途径（目标3）。该提案的总体目标是全面评估致病作用 先天免疫AD危险基因功能变异与AD发病机制的关系，并探讨其潜在的分子机制 网络，这将为AD患者提供新的治疗靶点。

Title: The impact of AD-associated genetic variants in 3D human mixed neural-glial models of AD Project summary A growing number of Alzheimer’s disease (AD)-associated genes are associated with innate immunity and neuroinflammatory pathways. Network-based integrative analyses of AD-related genes have shown that microglial gene networks are strongly associated with AD neuropathology (1,5). We have shown that the protective AD-associated CD33 variant, rs3865444, leads to reduced CD33 expression and lower levels of Aβ42)(1). Conversely, microglial TREM2 variants, which increase AD risk, reduce microglial clearance of Ab. In addition to AD-linked functional variants in CD33 and TREM2, our AD whole genome sequencing (WGS) and whole exome sequencing (WES) datasets from AD families and case-controls, have revealed functional variants in AD-associated microglial genes linked to innate immunity and neuroinflammation, including CD33, TREM2, MS4A cluster, ABCA7, ABI3, PLGC2, CR1, and others. To test the impact of microglial genetic variants on AD pathogenesis on human genetic background, we developed a novel 3D human neuron- astrocyte-microglia tri-culture AD model using a unique 3D microfluidic system. We demonstrated that human microglial cells are recruited towards 3D AD (Ab-producing) neuron-astrocyte cultures via microglia-specific migration channels, in a chemokine-dependent manner, leading to neuroinflammation and neurodegeneration. Here, we propose to use our extensive collection of AD WGS and WES datasets, together with our 3D human tri-culture AD model, to evaluate the pathogenic effects of functional variants in AD-associated innate immune genes linked to neuroinflammation. In Aim 1, we will identify functional genomic variants and enriched gene networks that are linked to innate immunity and neuroinflammation. We will then examine the pathogenic roles of microglial AD risk or protective genes and their functional variants in 3D human mixed neural-astrocyte- microglial models of AD (Aim 2), explore AD pathogenic pathways that are linked to microglial AD risk genes and their functional variants using integrated multi-omics approaches, and validate selectively blocking these pathway (Aim 3). The overarching goals of this proposal are to comprehensively assess the pathogenic effects of functional variants in innate immune AD-risk genes on AD pathogenesis and explore underlying molecular networks, which will provide novel therapeutic targets for AD patients.