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

• 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
• 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' s Disease; Alzheimer' 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

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年的培训计划，以发展学术生涯为重点， 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 小胶质细胞，视网膜和大脑中的常驻免疫细胞，在青光眼的发病机制中。我们的初步 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 疾病相关分子标记（MGnD），其与脑神经退行性疾病共享。在 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 显著上调APOE的产生，APOE是大脑中的主要脂蛋白。APOE最近被发现 关键调节大脑小胶质细胞中的MGnD分子特征，并与阿尔茨海默氏症有遗传联系 老年性黄斑变性和青光眼。此外，我们还发现， APOE仅在髓样细胞（小胶质细胞和外周单核细胞/巨噬细胞）中被靶向保护 微珠诱发的青光眼我们假设APOE控制视网膜小胶质细胞从 在缺乏APOE的情况下，小胶质细胞仍然存在于神经系统中。 稳态，导致视网膜神经炎性反应和RGC变性减少 眼内压（IOP）升高。我们将在以下具体目标中讨论这一假设： 1)确定小胶质细胞特异性APOE靶向在青光眼中的功能影响。为此，我们将 解决是否使用他莫昔芬诱导的Cx 3cr 1-CreERT 2 APOEfl/fl选择性消融小胶质细胞中的APOE 小鼠在IOP诱导后导致行为和功能性神经保护，如通过视动学评估的 反应，视网膜电图和视觉诱发电位测试。 2)研究APOE信号通路在青光眼发病机制中的作用。我们将 研究靶向小胶质细胞中的APOE使这些细胞保持稳态的假设， 导致凋亡神经元吞噬作用和细胞因子产生减少。 3)描述人载脂蛋白E亚型在小鼠青光眼模型中的作用。通过使用新 人源化-floxed APOE e2，e3和e4小鼠，我们将研究具有APOE e4等位基因的小鼠 显示出改变的小胶质细胞分子特征，并且在微珠诱导后对RGC损失不太敏感。 眼压升高。 这项研究概述了这项建议将有助于调查的作用，载脂蛋白E信号在小胶质细胞， 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治疗方法。 疾病这项研究解决了青光眼神经炎症的一个未充分研究的领域， 我作为一个独立的临床科学家的成功职业生涯。