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

基本信息

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
项目类别：
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&apos s Disease Alzheimer&apos s disease brain Alzheimer&apos 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

项目摘要

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.

阿尔茨海默病（AD）是最常见的神经退行性疾病，小胶质细胞在其中发挥着重要作用。支持正常的中枢神经系统功能，但在疾病中可能会导致神经退行性变。稳态 (M0) 和神经退行性 (MGnD) 小胶质细胞，也称为疾病相关小胶质细胞 (DAM)，在不同的细胞中通过 TGFb 的相互抑制和 APOE 信号的诱导来调节然而，这两种主要表型的作用以及它们如何在神经退行性小鼠模型中发挥作用。重要的是，靶向小胶质细胞 APOE 信号恢复仍然是一个主要问题。小胶质细胞的稳态特征与急性和慢性模型中的神经保护相关 APOE 信号以细胞自主方式抑制 PU.1 和 TGFβ 信号。 APOE 具有三种变体：ε2、ε3 和 ε4。APOE ε4 是晚发性阿尔茨海默病最强的遗传风险因素。我们的初步数据显示：1) 人源化 APOE 小胶质细胞中 PU.1 的表达增加 ε4 小鼠；2) 小胶质细胞中 APOE ε4 的表达损害了小胶质细胞诱导 MGnD 表型的反应 3) 删除小胶质细胞 APOE ε4 可恢复 APP/PS1 小鼠与星形胶质细胞相关的 MGnD 表型 Ab-斑块的募集和神经炎斑块的减少这些数据表明 APOE ε4 信号传导。是 APP/PS1 小鼠小胶质细胞中的一个重要调节途径。根据这些发现，我们在 APP/PS1 小鼠中捕获了这一点。 APOE ε4 携带者，APOE ε4“锁定”小胶质细胞处于稳态，导致吞噬细胞受损功能和失调的小胶质细胞-星形胶质细胞串扰，这可能会产生根本性后果对于 AD 的发展，我们将实现以下目标：目标 1：确定 APOE ε4 对小胶质细胞转录调控的作用及其与小胶质细胞的串扰 AD 和非痴呆受试者中的星形胶质细胞携带不同的 APOE 等位基因。人类 APOE ε4 影响细胞反应、相互作用途径和功能的转录特征调节，重点关注小胶质细胞和星形胶质细胞。目标 2：在单细胞分辨率下验证 APOE ε4 小胶质细胞和星形胶质细胞的空间差异。将使用免疫组织化学验证大脑中小胶质细胞和星形胶质细胞基因表达的差异特异性标记和多重抗误差荧光原位杂交 (MERFISH)。总之，本研究旨在验证 APOE ε4 是否损害转录、空间和功能 AD 脑中 MGnD-小胶质细胞的调节及其与星形胶质细胞的串扰。