Dissect regulation of glial nets surrounding amyloid plaques in Alzheimer's disease

剖析阿尔茨海默病中淀粉样斑块周围神经胶质网的调节

基本信息

批准号：
10467139
负责人：
Roland Horst Friedel
金额：
$ 180万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
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：
2022-05-05 至 2025-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10467139
关键词：
APP-PS1 Abeta clearance Ablation Address Affect Alzheimer&apos s Disease Alzheimer&apos s disease model Alzheimer&apos s disease pathology Alzheimer&apos s disease patient Alzheimer&apos s disease risk Amyloid Amyloid deposition Anatomy Apolipoprotein E Astrocytes Attenuated Behavioral Bioinformatics Biological Assay Biology Cell Nucleus Cells Clinical Clustered Regularly Interspaced Short Palindromic Repeats Coculture Techniques Communication Computer Analysis Data Dependence Deposition Disease Progression Electrophysiology (science)Functional disorder Gene Expression Genes Genetic Transcription Genetic study Human Immunohistochemistry Inflammatory Investigation Late Onset Alzheimer Disease Link Mediating Microglia Modeling Molecular Mus Mutant Strains Mice Nerve Degeneration Neurons Outcome Pathogenesis Pathology Pathway Analysis Physiological Processes Pilot Projects Play Process Regulation Role Secure Senile Plaques Series Signal Transduction Structure Surveys System Tauopathies Testing Up-Regulation aged axon guidance base cell type cognitive function cognitive performance cohort data modeling gene network genomic data glial activation improved in vivo induced pluripotent stem cell inflammatory milieu insight interdisciplinary approach mouse genetics mouse model multidisciplinary mutant neuroinflammation neurotoxicity neurotransmission novel novel therapeutics plexin receptor response risk variant single-cell RNA sequencing tau Proteins transcriptome sequencing transcriptomics β-amyloid burden

项目摘要

PROJECT SUMMARY The pathophysiology of Alzheimer’s disease (AD) remains unclear. Amyloid plaques are surrounded by reactive astrocytes and microglia, forming glial nets that affect amyloid spreading and inflammatory milieu. However, the mechanisms of inter-glial communication in glial nets are poorly understood. Our recent integrated network analysis of -omics data from late-onset AD patients identified the axon guidance receptor Plexin-B1 as a hub gene in an astrocyte-specific subnetwork. We have confirmed that Plexin-B1 is predominantly expressed in astrocytes and that it is upregulated in glial nets of AD patients. Remarkably, our pilot study with an amyloidogenic mouse model of AD showed that Plexin-B1 deletion markedly altered the structure of peri-plaque glial nets. Plexin-B1 deletion resulted in attenuated astrocyte reactivity, reduced cellular spacing of glial nets, and a higher coverage of plaques by microglia, leading to a shift of plaques to a dense core type. These changes of glial nets were associated with an overall reduction in plaque burden and neuritic dystrophy. Here we will expand our preliminary studies to further test the central hypothesis that glial activation and cellular interactions in glial nets, as regulated by Plexin-B1, affect amyloid aggregates and neurotoxicity in AD. Blocking Plexin-B1 may thus present a new opportunity to attenuate astrocyte reactivity in glial nets, reducing amyloid burden and neuroinflammation, thereby slowing down AD progression. In Aim 1, we aim to build cell type-specific glial signaling networks in AD, and to identify Plexin-B1-mediated gene modules in glial nets. We will analyze single cell transcriptomic data from both AD patients and AD mice (with and without Plexin-B1 deletion) to define coregulated gene networks in reactive astrocytes and activated microglia that are associated with Plexin-B1 signaling. In Aim 2, we will carry out a series of functional assays in glial cultures to study the role of Plexin-B1 in mediating astrocyte activation upon amyloid challenge. Human iPSC-derived astrocytes with Plexin-B1 deletion by CRISPR-Cas will be compared to primary astrocytes from Plexin-B1 mutant mice. We will then model in astrocyte/microglia co-cultures glial interactions in response to amyloid challenge in dependence of Plexin- B1. In Aim 3, we will conduct in vivo studies using mouse AD models to investigate in detail the impact of Plexin- B1 deletion on glial nets, plaque deposition, neuronal function and cognitive performance. Both an amyloidogenic and a tauopathy model of AD will be evaluated at early and advanced stages. We expect to demonstrate that Plexin-B1 deletion leads to attenuated astrocyte reactivity in glial nets, reduced cellular spacing, increased microglial coverage of amyloid plaques, and a shift to dense-core plaques and thus less neurotoxicity, as indicated by pilot data. Altogether, our study will provide new insights into the contribution of glial nets and Plexin- B1 to the neurodegenerative processes in AD, thus providing new therapeutic angles.

项目概要阿尔茨海默病 (AD) 的病理生理学仍不清楚，淀粉样蛋白斑块被反应性斑块包围。星形胶质细胞和小胶质细胞，形成影响淀粉样蛋白扩散和炎症环境的神经胶质网。我们对神经胶质网络中神经胶质间通信的机制知之甚少。对晚发 AD 患者组学数据的分析确定了轴突引导受体 Plexin-B1 作为枢纽我们已经证实 Plexin-B1 主要在星形胶质细胞特异性子网络中表达。值得注意的是，我们的初步研究表明，星形胶质细胞在 AD 患者的神经胶质网络中表达上调。 AD 淀粉样蛋白形成小鼠模型表明，Plexin-B1 缺失显着改变了斑块周围的结构 Plexin-B1 缺失导致星形胶质细胞反应性减弱，神经胶质网的细胞间距减小，小胶质细胞对斑块的覆盖率更高，导致斑块转变为致密核心类型。神经胶质网的数量与斑块负担和神经营养不良的总体减少有关。扩大我们的初步研究，以进一步检验神经胶质激活和细胞相互作用的中心假设神经胶质网中的 Plexin-B1 调节，影响 AD 中的淀粉样蛋白聚集和神经毒性。因此可能提供一个新的机会来减弱神经胶质网中星形胶质细胞的反应性，减少淀粉样蛋白的负担和在目标 1 中，我们的目标是构建细胞类型特异性的神经胶质细胞。我们将分析 AD 中的信号网络，并识别神经胶质网络中 Plexin-B1 介导的基因模块。来自 AD 患者和 AD 小鼠（有或没有 Plexin-B1 缺失）的细胞转录组数据来定义与 Plexin-B1 相关的反应性星形胶质细胞和活化小胶质细胞中的共同调节基因网络在目标 2 中，我们将在神经胶质培养物中进行一系列功能测定，以研究 Plexin-B1 的作用。使用 Plexin-B1 介导淀粉样蛋白攻击后的人 iPSC 衍生的星形胶质细胞激活。 CRISPR-Cas 删除将与来自 Plexin-B1 突变小鼠的原代星形胶质细胞进行比较，然后我们将进行建模。在星形胶质细胞/小胶质细胞共培养中，神经胶质细胞相互作用响应淀粉样蛋白挑战，依赖于 Plexin- B1. 在目标 3 中，我们将使用小鼠 AD 模型进行体内研究，以详细研究 Plexin- 的影响。 B1 缺失对神经胶质网、斑块沉积、神经功能和认知表现的影响均是淀粉样蛋白生成。我们将在早期和晚期阶段对 AD 的 tau 蛋白病模型进行评估，以证明这一点。 Plexin-B1 缺失导致神经胶质网中星形胶质细胞的反应性减弱、细胞间距减小、细胞间距增加小胶质细胞覆盖淀粉样斑块，并转向致密核心斑块，从而减少神经毒性，如总而言之，我们的研究将为神经胶质网和 Plexin 的贡献提供新的见解。 B1针对AD的神经退行性过程，从而提供新的治疗角度。