Nrf2 signaling and oxidative stress in age-related macular degeneration

项目摘要 老年性黄斑变性(AMD)是老年人失明的主要原因，但患者 早期的疾病是没有治疗的。为了解决这一缺陷，这项提议侧重于早期疾病。二 早期AMD的关键事件是视网膜色素上皮细胞(RPE)功能障碍和玻璃体生物发生。 未充分中和的活性氧簇(ROS)和调节失调的先天免疫相互作用， 发挥举足轻重的作用。氧化动态平衡的核心是Nrf2转录因子，尤其是在线粒体中。 它控制着最全面的抗氧化反应系统。NRF2信号可能会因 衰老和/或吸烟。这项提案的目的是定义Nrf2如何保护RPE线粒体 功能障碍和不受监管的先天免疫系统。需要检验的假设是，Nrf2信号受损 导致线粒体和RPE功能障碍，导致氧化、炎症和病理 微环境。提出的具体目标是：1.确定Nrf2信号受损的程度 吸烟导致未中和的线粒体ROS和RPE功能障碍。我们的 假设RPE中的Nrf2信号因衰老和长期吸烟而受损，减少线粒体 抗氧化防御导致不能充分中和ROS和RPE功能障碍。2.确定范围 受损的Nrf2信号减少了有丝分裂，并导致了香烟的RPE功能障碍 暴露在烟雾中。我们的假设是RPE中的Nrf2信号因衰老和长期吸烟而受损 减少有丝分裂，累积增加功能不全的线粒体的数量 中和ROS，导致RPE功能障碍。3.确定Nrf2信号受损的程度 扰乱了对先天免疫的调节。根据我们的工作显示CS和 Nrf2缺乏，我们的假设是Nrf2信号受损会放大氧化应激，从而激活 炎症小体通过巨噬细胞的聚集促进促炎微环境 功能受损。这些贡献意义重大，因为它们将把NRF2确立为 早期的AMD。这项研究具有创新性，因为它将调查未被研究的(Nrf2信号在 线粒体抗氧化剂和有丝分裂)，未分解(炎症体和巨噬细胞功能)和独特 (ROS和天然免疫的协同作用)因子对RPE和巨噬细胞功能的影响 ART基因小鼠具有新鲜的，但决定性的因素，以前没有测试过。巨噬细胞将成为 从定义表型和功能的新角度进行研究，因为两者都受其影响 周围的环境。我们发现Nrf2随年龄和CS的减少而减少，这会产生C3a和IL-1b，这是一种关键 炎症体的底物，以及拟议的将补体与炎症体联系起来的研究， 巨噬细胞的功能和AMD的表型是高度创新的。靶向治疗使Nrf2重新焕发活力 这项工作有望维持氧化动态平衡和保护性先天免疫。

Project Summary Age-related macular degeneration (AMD) is the leading cause of blindness among the elderly, yet patients with early disease are without therapy. To address this shortcoming, this proposal focuses on early disease. Two key events in early AMD are retinal pigment epithelial cell (RPE) dysfunction and drusen biogenesis. Inadequately neutralized reactive oxygen species (ROS) and dysregulated innate immunity interact together to play a pivotal role. Central to oxidative homeostasis, especially in mitochondria, is the Nrf2 transcription factor, which controls the most comprehensive antioxidant response system. Nrf2 signaling can become impaired with aging and/or smoking. The objective of this proposal to define how Nrf2 protects against RPE mitochondrial dysfunction and unregulated innate immunity. The hypothesis to be tested is that that impaired Nrf2 signaling induces mitochondrial and RPE dysfunction that results in an oxidative, inflammatory, and pathologic microenvironment. The proposed specific aims are: 1. Determine the extent that impaired Nrf2 signaling leads to un-neutralized mitochondrial ROS and RPE dysfunction with cigarette smoke exposure. Our hypothesis is that impaired Nrf2 signaling in the RPE from aging and chronic smoking reduces mitochondrial antioxidant defense resulting in inadequately neutralized ROS and RPE dysfunction. 2. Determine the extent that impaired Nrf2 signaling decreases mitophagy, and results in RPE dysfunction with cigarette smoke exposure. Our hypothesis is that impaired Nrf2 signaling in the RPE from aging and chronic smoking decreases mitophagy, cumulatively increasing the number of dysfunctional mitochondria and inadequately neutralized ROS, resulting in RPE dysfunction. 3. Determine the extent that impaired Nrf2 signaling disrupts regulation of innate immunity. Based on our work showing C3a and IL-1b generation by CS and Nrf2 deficiency, our hypothesis is that impaired Nrf2 signaling magnifies oxidative stress, which activates the inflammasome to promote a pro-inflammatory microenvironment with accumulation of macrophages with impaired function. These contributions are significant because they will establish Nrf2 as a treatment target for early AMD. The research is innovative since it will investigate understudied (decreased Nrf2 signaling on mitochondrial antioxidants and mitophagy), unresolved (inflammasome and macrophage function) and unique (the synergy of ROS and innate immunity) factors on RPE and macrophage function using unique, state-of-the- art genetic mice with fresh, but decisive factors that have not been previously tested. Macrophages will be studied from a new perspective that defines both phenotype and function since both are influenced by their surroundings. Our discovery of reduced Nrf2 with aging and CS, which generates C3a and IL-1b, a key substrate of the inflammasome, and the proposed studies, which will link complement with the inflammasome, macrophage function, and an AMD phenotype, is highly innovative. Targeted therapy that reinvigorates Nrf2 to maintain oxidative homeostasis and protective innate immunity is expected to result from this work.