The Role of APOE Signaling in Microglia in Glaucoma

APOE 信号传导在青光眼小胶质细胞中的作用

基本信息

批准号：
10238886
负责人：
Milica Margeta
金额：
$ 23.43万
依托单位：
MASSACHUSETTS EYE AND EAR INFIRMARY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-01 至 2022-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10238886
关键词：
Ablation Address Age related macular degeneration Alleles Alzheimer&apos s Disease Alzheimer&apos s disease model Amyotrophic Lateral Sclerosis Animals Apolipoprotein E Apoptotic Area Behavioral Biological Response Modifiers Biology Brain Cell Differentiation process Cell Survival Cells Chronic Clinical Data Development Disease Electroretinography Endothelin-1 Exhibits Eye Genes Glaucoma Goals Human Immune Knowledge Laboratories Late Onset Alzheimer Disease Link Lipoproteins Literature LoxP-flanked allele Microglia Microspheres Modeling Molecular Profiling Monoclonal Antibodies Multiple Sclerosis Mus Myeloid Cells Nerve Degeneration Nervous system structure Neurodegenerative Disorders Neurons Optic Nerve Pathogenesis Peripheral Personal Communication Phagocytosis Phenotype Physiologic Intraocular Pressure Play Population Production Program Development Protein Isoforms Publishing Research Retina Retinal Ganglion Cells Risk Factors Role Scientist Signal Transduction Tamoxifen Testing Training Programs Variant Visual Fields Visual evoked cortical potential apolipoprotein E-2 apolipoprotein E-4 career cell injury cell type common treatment cytokine macrophage modifiable risk monocyte mouse model neurodegenerative phenotype neuroinflammation neuroprotection neurotoxic novel optic cup recruit response retinal ganglion cell degeneration transcriptome sequencing

项目摘要

This proposal describes a 3-year training program for the development of an academic career focused on understanding the role of retinal neuroinflammation in glaucoma. My research goal is to elucidate the role of microglia, resident immune cells in the retina and the brain, in the pathogenesis of glaucoma. Our preliminary data demonstrate that in the microbead glaucoma model, microglia suppress homeostatic genes and induce a disease-associated molecular signature (MGnD), which is shared with brain neurodegenerative diseases. In addition to the induction of proinflammatory cytokines and neurotoxic substances, MGnD microglia also significantly upregulate production of APOE, the major lipoprotein in the brain. APOE has recently been found to critically regulate MGnD molecular signature in brain microglia, and is genetically linked to Alzheimer’s disease, age-related macular degeneration, and glaucoma. Furthermore, we have found that mice in which APOE has been targeted only in myeloid cells (microglia and peripheral monocytes/macrophages) are protected from microbead-induced glaucoma. We hypothesize that APOE controls the switch of retinal microglia from homeostatic to a harmful neurodegenerative phenotype, and that in the absence of APOE, microglia remain in the homeostatic state, leading to a decreased retinal neuroinflammatory response and RGC degeneration following intraocular pressure (IOP) elevation. We will address this hypothesis in the following specific aims: 1) Determine the functional impact of microglia-specific APOE targeting in glaucoma. In this aim, we will address whether selective ablation of APOE in microglia utilizing tamoxifen-inducible Cx3cr1-CreERT2 APOEfl/fl mice leads to behavioral and functional neuroprotection after IOP induction, as assessed by optokinetic response, electroretinogram, and visual evoked potential testing. 2) Investigate the mechanism by which APOE signaling contributes to glaucoma pathogenesis. We will investigate the hypothesis that targeting APOE in microglia maintains these cells in the homeostatic state, resulting in decreased apoptotic neuron phagocytosis and cytokine production. 3) Characterize the role of human APOE isoforms in the mouse model of glaucoma. By using novel humanized-floxed APOE e2, e3 and e4 mice, we will investigate the hypothesis that mice with APOE e4 allele exhibit an altered microglial molecular signature and are less susceptible to RGC loss after microbead-induced IOP elevation. The research outlined in this proposal will serve to investigate the role of APOE signaling in microglia in glaucoma, with the ultimate goal of developing novel neuroprotective treatments for this common blinding disease. This research addresses an understudied area of neuroinflammation in glaucoma while also preparing me for a successful career as an independent clinician-scientist.

该提案描述了一个为期 3 年的学术职业发展培训计划，重点关注了解视网膜神经炎症在青光眼中的作用我的研究目标是阐明视网膜神经炎症的作用。小胶质细胞是视网膜和大脑中的常驻免疫细胞，在青光眼的发病机制中发挥着重要作用。数据表明，在微珠青光眼模型中，小胶质细胞抑制稳态基因并诱导疾病相关分子特征（MGnD），与脑神经退行性疾病共有。除了诱导促炎细胞因子和神经毒性物质外，MGnD 小胶质细胞还显着上调 APOE 的产生，APOE 是最近发现的大脑中的主要脂蛋白。严格调节大脑小胶质细胞中的 MGnD 分子特征，并且与阿尔茨海默病有遗传关联此外，我们还发现小鼠患有以下疾病： APOE 仅针对骨髓细胞（小胶质细胞和外周单核细胞/巨噬细胞）受到保护我们推测 APOE 控制视网膜小胶质细胞的转换。对有害的神经退行性表型具有稳态作用，并且在缺乏 APOE 的情况下，小胶质细胞仍保持在稳态，导致视网膜神经炎症反应减少和 RGC 变性眼压（IOP）升高后，我们将通过以下具体目标来解决这一假设： 1) 确定小胶质细胞特异性 APOE 靶向对青光眼的功能影响。解决是否利用他莫昔芬诱导的 Cx3cr1-CreERT2 APOEfl/fl 选择性消融小胶质细胞中的 APOE 通过光动学评估，小鼠在 IOP 诱导后产生行为和功能性神经保护反应、视网膜电图和视觉诱发电位测试。 2) 研究APOE信号传导促进青光眼发病的机制。研究针对小胶质细胞中的 APOE 维持这些细胞处于稳态的假设，导致凋亡神经元吞噬作用和细胞因子产生减少。 3) 通过使用新颖的方法表征人类 APOE 亚型在小鼠青光眼模型中的作用。人源化 APOE e2、e3 和 e4 小鼠，我们将研究带有 APOE e4 等位基因的小鼠的假设表现出改变的小胶质细胞分子特征，并且在微珠诱导后不易受到 RGC 损失的影响眼压升高。本提案中概述的研究将有助于研究 APOE 信号在小胶质细胞中的作用青光眼，最终目标是开发针对这种常见致盲的新型神经保护疗法这项研究涉及青光眼神经炎症的一个尚未研究的领域，同时也为治疗青光眼做好了准备。我作为一名独立的临床医生科学家取得了成功的职业生涯。