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Mechanisms of age-related RPE dysfunction and CNV

年龄相关的 RPE 功能障碍和 CNV 的机制

基本信息

批准号：
8481553
负责人：
JIYANG CAI
金额：
$ 36.37万
依托单位：
UNIVERSITY OF TEXAS MED BR GALVESTON
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-07-01 至 2017-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8481553
关键词：
Address Age related macular degeneration Animal Model Anti-Inflammatory Agents Anti-inflammatory Antioxidants Autophagocytosis Autophagosome Biological Assay Blindness Bruch&apos s basal membrane structure Candidate Disease Gene Cells Chloroquine Choroid Choroidal Neovascularization Chronic Clinical Treatment Coculture Techniques Complement Data Deposition Development Diet Disease Disease Progression Drug Metabolic Detoxication Drusen Elderly Etiology Experimental Models Exudative age-related macular degeneration Eye Fatty acid glycerol esters Functional disorder Gene Expression Profile Genes Genetic Genetic Research Human Immune response Infiltration Inflammation Inflammatory Inflammatory Response Intervention Knock-out Knockout Mice Knowledge Lead Lesion Leucine Light Lipofuscin Lysosomes Macrophage Activation Maps Measures Mediating Membrane Metabolic Microtubule-Associated Proteins Modeling Molecular Molecular Target Mus Myeloid Cells Pathologic Processes Pathology Pathway interactions Peroxisome Proliferator-Activated Receptors Phagocytosis Photoreceptors Production Progressive Disease Property Protein Export Pathway Proteins Proteolysis Proteomics Reporter Retina Retinal Role Staging Stimulus Structure of retinal pigment epithelium System Testing Tissue-Specific Gene Expression Toxic effect Vacuole Vesicle Wild Type Mouse Work age related base cell type chemokine complement system cytokine design gene function geographic atrophy in vivo inhibition of autophagy inhibitor/antagonist macromolecule macrophage mouse model novel novel therapeutics nuclear factor-erythroid 2 overexpression repaired research study response small hairpin RNA subretinal injection tool

项目摘要

DESCRIPTION (provided by applicant): Age-related macular degeneration (AMD) is the leading cause of blindness in elderly people. The disease starts with dysfunction of the retinal pigment epithelium (RPE) and formation of drusen, and will further progress to chronic inflammation in the sub-RPE space, geographic atrophy and choroidal neovascularization (CNV). Despite the recent progresses in genetic research and clinical treatment of exudative AMD, its etiology is largely unclear and currently there is no effective cure for dry AMD. We have recently developed an animal model of AMD using knockout mice deficient of nuclear factor erythroid 2-related factor 2 (Nrf2). The Nrf2-/- mice developed AMD-like retinal pathology including age-dependent RPE degeneration, spontaneous CNV and sub-RPE deposit of complement-related proteins. In our preliminary studies, we further demonstrated that Nrf2 is an important regulator of RPE autophagy and macrophage activation. We found that Nrf2-deficient RPE cells had increased accumulation of autophagic vacuoles and lipofuscin in vivo, indicating less efficient degradation by lysosome. Substantially more severe RPE pathology was developed in Nrf2-/- mice in a chronic toxicity model using chloroquine, an inhibitor of lysosome function and RPE autophagy. With differential gene expression assay, we identified Nramp1 as a downstream gene of Nrf2 with novel functions of controlling autophagosome formation. In a model of experimental CNV, Nrf2-/- mice showed significantly increased lesion size and macrophage infiltration than the wild type mice received the same treatment. When co-cultured with RPE, Nrf2-/- macrophages showed more robust pro-inflammatory responses than the wild type cells. Based on these findings, we hypothesize that Nrf2 is an essential regulator of multiple protective mechanisms against age-dependent RPE dysfunction and subsequent CNV. Using Nrf2-/- mice as an established model, experiments will be performed to further examine the mechanisms of RPE degeneration and to explore the roles of chronic inflammation mediated by infiltrating macrophages. Specific Aim 1 will determine whether Nrf2 regulates RPE autophagy by Nramp1-dependent mechanisms. Specific Aim 2 will determine whether inhibiting RPE autophagy will accelerate the development of AMD-related pathology in Nrf2-/- mice, and examine the functional interactions between RPE autophagy pathway and exosomal protein export. Specific Aim 3 will determine whether Nrf2 regulates polarized macrophage activation in experimental CNV. Results from these studies will reveal new mechanisms of the pathobiology of AMD and further define Nrf2 as a molecular target for intervention.

描述（由申请人提供）：视网膜相关性黄斑变性（AMD）是老年人失明的主要原因。该疾病开始于视网膜色素上皮（RPE）的功能障碍和玻璃疣的形成，并且将进一步发展为RPE下空间中的慢性炎症、地图状萎缩和脉络膜新生血管（CNV）。尽管渗出型AMD的遗传学研究和临床治疗取得了很大进展，但其病因尚不清楚，目前对干性AMD尚无有效的治疗方法。我们最近开发了一种AMD的动物模型，使用核因子红细胞2相关因子2（Nrf 2）缺陷的敲除小鼠。Nrf 2-/-小鼠出现AMD样视网膜病变，包括年龄依赖性RPE变性、自发性CNV和补体相关蛋白的RPE下存款。在我们的初步研究中，我们进一步证明了Nrf 2是RPE自噬和巨噬细胞活化的重要调节因子。我们发现，Nrf 2缺陷型RPE细胞体内自噬空泡和脂褐素的积累增加，表明溶酶体降解效率较低。在使用氯喹（溶酶体功能和RPE自噬的抑制剂）的慢性毒性模型中，在Nrf 2-/-小鼠中发展出实质上更严重的RPE病理。通过基因差异表达分析，我们确定Nramp 1是Nrf 2的下游基因，具有控制自噬体形成的新功能。在实验CNV模型中，Nrf 2-/-小鼠显示出比接受相同治疗的野生型小鼠显著增加的病变大小和巨噬细胞浸润。当与RPE共培养时，Nrf 2-/-巨噬细胞显示出比野生型细胞更强的促炎反应。基于这些发现，我们假设Nrf 2是针对年龄依赖性RPE功能障碍和随后的CNV的多种保护机制的重要调节剂。使用Nrf 2-/-小鼠作为已建立的模型，将进行实验以进一步检查RPE变性的机制并探索由浸润的巨噬细胞介导的慢性炎症的作用。具体目标1将确定Nrf 2是否通过Nramp 1依赖性机制调节RPE自噬。具体目标2将确定抑制RPE自噬是否会加速Nrf 2-/-小鼠中AMD相关病理的发展，并检查RPE自噬途径和外泌体蛋白输出之间的功能相互作用。具体目标3将确定Nrf 2是否调节实验CNV中的极化巨噬细胞活化。这些研究的结果将揭示AMD病理生物学的新机制，并进一步将Nrf 2定义为干预的分子靶点。