Regulation of RPE degeneration by REV-ERBalpha

项目摘要 老年性黄斑变性患者视网膜色素上皮(RPE)变性导致视力丧失 (AMD)和视网膜色素变性(RP)。促进RPE(从而光感受器)的存活对 保护视力。虽然许多因素导致眼部疾病的RPE变性，包括 在遗传和环境因素中，氧化应激是RPE功能障碍的主要因素之一。 变性，主要由过量的线粒体氧化产物和吞噬相关的脂质引起 氧化。然而，氧化应激失调导致RPE功能障碍和 眼科疾病中的变性仍然没有完全定义。此外，缺乏有效的方法来 促进RPE的健康和生存。识别识别RPE氧化还原反应的基本分子链 (还原/氧化)环境对RPE功能障碍和变性的影响将有助于识别 恢复老化RPE内源性细胞防御系统和预防视力丧失的新分子靶点 在眼科疾病方面。在这个项目中，我们确定了一个氧化还原敏感的核受体rev-erbα，它可能作为一种 连接RPE氧化还原动态平衡和RPE抗氧化防御的转录调控因子影响RPE 退化。REV-ERBα作为一种氧化还原和配体依赖的转录因子，控制着 生物过程，包括细胞新陈代谢、炎症和昼夜节律。我们的初步结果 结果表明：1)REV-ERBα水平随增龄而下降；2)小鼠REV-ERBα基因缺失导致 与年龄相关的RPE变性发展，伴有视网膜下沉积，视功能受损和 抑制RPE吞噬功能；3)RPE特异性缺失REV-ERBα导致类似的眼底损害；4) REV-ERBα缺乏加剧了化学诱导的视网膜色素上皮损伤和视网膜毒性 4)REV-ERBα在体内外对视网膜色素上皮细胞的保护作用；5)REV-ERBα直接调节细胞核 因子红系相关因子2(NRF2)转录及其相关的抗氧化基因。我们假设 REV-ERBα是RPE细胞内抗氧化防御系统的一种新的氧化还原敏感调节因子。 激活REV-ERBα是保护视网膜色素上皮的一种新方法。这一假说将用遗传学和 急性和慢性视网膜色素上皮损伤模型中调节REV-ERBα的药理学研究进展 退化。这项工作将从机制上探讨REV-ERBα是否保护小瓶增强的RPE 抗氧化剂自卫。这项拟议的工作将揭示新的分子调控机制 RPE变性和新的可药物分子靶点，用于开发抗RPE的改进策略 眼科疾病中的损害和退化。

Project Summary Degeneration of retinal pigment epithelium (RPE) causes vision loss in age-related macular degeneration (AMD) and retinitis pigmentosa (RP). Promoting survival of RPE (and thereby photoreceptors) is critical for preserving vision. Whereas many factors contribute to RPE degeneration in eye diseases including both genetic and environmental ones, oxidative stress is one of the major contributors to RPE dysfunction and degeneration, derived primarily from excess mitochondrial oxidative products, and phagocytosis-related lipid oxidation. However, the processes through which dysregulated oxidative stress leads to RPE dysfunction and degeneration in eye diseases remain incompletely defined. Moreover, there is lack of effective approaches to promote RPE health and survival. Identification of the basic molecular links which sense RPE redox (reduction/oxidation) environment to impact RPE dysfunction and degeneration will aid in the identification of new molecular targets to rejuvenate endogenous cellular defense system in aging RPE and prevent vision loss in eye diseases. In this project we identified a redox-sensing nuclear receptor REV-ERBα, which may act as a transcriptional regulator linking RPE redox homeostasis and RPE antioxidant defense to impact RPE degeneration. REV-ERBα, functioning as a redox- and ligand-dependent transcription factor, controls multiple biological processes including cellular metabolism, inflammation, and circadian rhythm. Our preliminary results show that: 1) REV-ERBα levels decline with aging in RPE; 2) genetic deletion of REV-ERBα in mice leads to age-related development of RPE degeneration, with subretinal deposits, impaired visual function and dampened RPE phagocytic function; 3) RPE specific deletion of REV-ERBα causes similar fundus lesions; 4) REV-ERBα deficiency exacerbates chemically-induced induced RPE damage and retinal toxicity in vivo and in vitro; 4) activation of REV-ERBα protects RPE in vitro and in vivo; and 5) REV-ERBα directly regulates nuclear factor erythroid-2 related factor 2 (NRF2) transcription and its associated antioxidant genes. We hypothesize that REV-ERBα is a novel redox-sensitive regulator of RPE intracellular antioxidant defense system, and activating REV-ERBα is a new way to protect RPE. This hypothesis will be evaluated with both genetic and pharmacological approaches of modulating REV-ERBα in both acute and chronic models of RPE damage and degeneration. Mechanistically this work will explore whether REV-ERBα protects RPE vial enhancing RPE antioxidant self-defense. This proposed work will uncover novel molecular regulatory mechanisms underlying RPE degeneration, and new druggable molecular targets for developing improved strategies to counter RPE damage and degeneration in eye diseases.