Mechanisms of age-related RPE dysfunction and CNV

年龄相关的 RPE 功能障碍和 CNV 的机制

• 批准号: 8263308
• 负责人: JIYANG CAI
• 金额: $ 39.61万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 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/8263308
• 关键词: Address; Age related macular degeneration; Animal Model; Anti-Inflammatory Agents; Anti-inflammatory; Antioxidants; Autophagocytosis; Autophagosome; Biological Assay; Blindness; Bruch' 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

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. PUBLIC HEALTH RELEVANCE: This project will use a newly developed mouse model of age-related macular degeneration (AMD) to examine the essential roles of nuclear factor erythroid 2-related factor 2 (Nrf2) in protecting the outer retina from age-related degeneration and associated immune responses. Results from the proposed studies can expand our knowledge on the molecular etiology of AMD and facilitate the design of better interventional agents that protect against vision loss in elderly people.

描述（由申请人提供）：与年龄相关的黄斑变性（AMD）是老年人失明的主要原因。该疾病始于视网膜色素上皮（RPE）的功能障碍和DRUSEN的形成，并将进一步发展为子RPE空间，地理萎缩和脉络膜新生血管形成（CNV）的慢性炎症。尽管最近在渗出症AMD的遗传研究和临床治疗方面取得了进展，但其病因在很大程度上尚不清楚，目前尚无有效的干疗法。我们最近使用缺乏与核因子2相关因子2（NRF2）的敲除小鼠开发了AMD的动物模型。 NRF2 - / - 小鼠开发了AMD样性视网膜病理学，包括年龄依赖性的RPE变性，自发CNV和补体相关蛋白的子RPE沉积。在我们的初步研究中，我们进一步证明了NRF2是RPE自噬和巨噬细胞激活的重要调节剂。我们发现NRF2缺陷型RPE细胞在体内积聚了自噬液泡和脂肪霉素的积累，表明溶酶体的效率降解较低。使用溶酶体功能和RPE自噬的抑制剂氯喹，在慢性毒性模型中，在NRF2 - / - 小鼠中开发了更严重的RPE病理。使用差异基因表达测定，我们将NRAMP1鉴定为NRF2的下游基因，具有控制自噬体形成的新功能。在实验CNV的模型中，NRF2 - / - 小鼠的病变大小和巨噬细胞浸润明显增加，而野生型小鼠则接受了相同的治疗方法。与RPE共培养时，NRF2 - / - 巨噬细胞显示出比野生型细胞更强大的促炎反应。基于这些发现，我们假设NRF2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。将使用NRF2 - / - 小鼠作为既定模型，将进行实验，以进一步检查RPE变性的机制，并探索渗透巨噬细胞介导的慢性炎症的作用。具体目标1将确定NRF2是否通过NRAMP1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NRF2 - / - 小鼠中与AMD相关病理的发展，并检查RPE自噬途径与外泌体蛋白质导出之间的功能相互作用。具体目标3将确定NRF2是否调节实验CNV中的极化巨噬细胞激活。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NRF2定义为干预的分子靶标。 公共卫生相关性：该项目将使用与年龄相关的黄斑变性（AMD）新开发的小鼠模型，以检查核因子红细胞2相关因子2（NRF2）在保护外部视网膜免受年龄相关变性和相关免疫反应中的基本作用。拟议的研究的结果可以扩大我们对AMD分子病因的了解，并促进更好的介入药物的设计，以防止老年人的视力丧失。