APOE e4 negative regulation of microglia-astrocytes crosstalk in Alzheimer's disease

APOE e4 对阿尔茨海默病中小胶质细胞-星形胶质细胞串扰的负调节

• 批准号: 10429190
• 负责人: Oleg Butovsky
• 金额: $ 42.92万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10429190
• 关键词: APP-PS1; Acute; Address; Affect; Alleles; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease risk; Astrocytes; Basic Science; Brain; Cells; Chronic; Clinical; Data; Development; Disease; Disease Progression; Disease associated microglia; Fluorescent in Situ Hybridization; Gene Expression; Gene Expression Profile; Genetic Transcription; Human; Immune; Immunohistochemistry; Impairment; Late Onset Alzheimer Disease; Microglia; Modeling; Mus; Nerve Degeneration; Neurodegenerative Disorders; Onset of illness; Pathology; Pathway interactions; Phagocytes; Phenotype; Play; Regulation; Regulatory Pathway; Resolution; Risk; Role; Senile Plaques; Signal Transduction; Spatial Distribution; Tissues; Transcriptional Regulation; Transforming Growth Factor beta; Variant; Work; apolipoprotein E-4; base; genetic risk factor; genome wide association study; mouse model; neurodegenerative phenotype; neuroprotection; non-demented; recruit; response; risk variant

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disorder. Microglia play an essential role in supporting normal CNS functions, but in disease may contribute to neurodegeneration. We identified homeostatic (M0) and neurodegenerative (MGnD) microglia, also referred to as disease associated microglia (DAM), that are regulated by the reciprocal suppression of TGFb and induction of APOE signaling in different neurodegenerative mouse models including AD. However, the role of these two major phenotypes and how they affect disease progression remains a major question. Importantly, targeting microglial APOE signaling restored the homeostatic signature of microglia associated with neuroprotection in acute and chronic models of neurodegeneration. APOE signaling suppressed PU.1 and TGFβ signaling in a cell-autonomous manner. Human APOE has three variants: ε2, ε3, and ε4. APOE ε4 is the strongest genetic risk factor for late-onset Alzheimer’s disease (LOAD). Our preliminary data show: 1) Increased expression of PU.1 in microglia from humanized APOE ε4 mice; 2) Expression of APOE ε4 in microglia impaired microglial response to induce a MGnD phenotype and 3) Deletion of microglial APOE ε4 restored MGnD phenotype in APP/PS1 mice associated with astrocytes recruitment towards Ab-plaques and reduction in neuritic plaques. These data indicate that APOE ε4 signaling is a crucial regulatory pathway in microglia in APP/PS1 mice. Based on these findings, we hypothesize that in APOE ε4 carriers, APOE ε4 ‘locks’ microglia in their homeostatic state leading to impaired phagocytic functions and dysregulated microglia-astrocyte crosstalk, which could have fundamental consequences for AD development. We will address our hypothesis in the following aims: Aim 1: Determine the role of APOE ε4 on transcriptional regulation of microglia and their crosstalk with astrocytes in AD and non-demented subjects carrying different APOE alleles. We will determine whether human APOE ε4 affects transcriptional signatures of cellular response, interactive pathways, and functional regulation, focusing on microglia and astrocytes. Aim 2: Validate the spatial differences in APOE ε4 microglia and astrocytes at single-cell resolution. We will validate the differences in microglia and astrocytic gene expression in brain, using immunohistochemistry of specific markers and multiplexed error-robust fluorescence in situ hybridization (MERFISH). IN SUMMARY, this study aims to validate whether APOE ε4 impairs transcriptional, spatial, and functional regulation of MGnD-microglia and their crosstalk with astrocytes in AD brain.

阿尔茨海默氏病（AD）是最普遍的神经退行性疾病。小胶质细胞在 支持正常的中枢神经系统功能，但在疾病中可能有助于神经退行性。我们确定了 稳态（M0）和神经退行性（MGND）小胶质细胞，也称为疾病相关的小胶质细胞 （DAM），受TGFB的相互抑制和不同的APOE信号的诱导来调节 神经退行性小鼠模型，包括AD。但是，这两种主要表型的作用以及它们如何 影响疾病进展仍然是一个主要问题。重要的是，针对小胶质APOE信号恢复 小胶质细胞的稳态特征与急性和慢性模型相关的小胶质细胞的稳态 神经变性。 APOE信号传导以细胞自主方式抑制PU.1和TGFβ信号传导。人类 APOE具有三个变体：ε2，ε3和ε4。 APOEε4是晚期阿尔茨海默氏症的强大遗传危险因素 疾病（负载）。我们的初步数据显示：1）人源化apoE中小胶质细胞中Pu.1的表达增加 ε4小鼠； 2）小胶质细胞中ApoEε4的表达受损的小胶质细胞反应，以诱导MGND表型和 3）删除与星形胶质细胞相关的APP/PS1小鼠中恢复的MGND表型的删除 招募AB-Plaques并减少神经质斑块。这些数据表明APOEε4信号传导 是APP/PS1小鼠中小胶质细胞中至关重要的调节途径。基于这些发现，我们假设 ApoEε4载体，ApoEε4“锁”小胶质细胞的稳态状态导致吞噬性受损 功能和失调的小胶质细胞 - 胃细胞串扰，这可能会带来基本的后果 用于广告开发。我们将在以下目的中解决我们的假设： 目标1：确定APOEε4在小胶质细胞转录调控及其串扰的作用 携带不同APOE等位基因的AD和非痴呆受试者的星形胶质细胞。我们将确定是否 人apoeε4影响细胞反应，互动途径和功能的转录特征 调节，专注于小胶质细胞和星形胶质细胞。 AIM 2：验证单细胞分辨率下APOEε4小胶质细胞和星形胶质细胞的空间差异。我们 将使用免疫组织化学来验证大脑中小胶质细胞和星形细胞基因表达的差异 特定标记和多路复用误差荧光原位杂交（Merfish）。 总而言之，本研究旨在验证APOEε4是否会损害转录，空间和功能 MGND-Microglia及其与AD大脑中星形胶质细胞的串扰调节。