Deciphering the role of mitochondrial/autophagy dysfunction in regulating inflammatory processes during AMD pathogenesis

破译线粒体/自噬功能障碍在 AMD 发病机制中调节炎症过程中的作用

• 批准号: 10664118
• 负责人: Sayan Ghosh
• 金额: $ 9.27万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10664118
• 关键词: Acetylcysteine; Address; Adhesions; Affect; Age related macular degeneration; Aging; Animal Model; Antioxidants; Automobile Driving; Autophagocytosis; Biochemical; Biological Assay; Blindness; Cell Communication; Cells; Cellular Assay; Choroid; Chronic; Data; Deposition; Disease; Dryness; Elderly; Environmental Risk Factor; Eye diseases; Flow Cytometry; Functional disorder; Genetic; Health; Histology; Homeostasis; Homing; Human; Hyperpigmentation; Immune; Immune system; Immunophenotyping; Impairment; Individual; Infiltration; Inflammasome; Inflammation; Inflammatory; Inflammatory Response; Intravenous; Knock-in; Knock-in Mouse; Laser Scanning Confocal Microscopy; Lead; Mediating; Mentors; Messenger RNA; Microglia; Mitochondria; Modality; Molecular; Morphology; Mus; NOD/SCID mouse; Nonexudative age-related macular degeneration; Oxidation-Reduction; Oxidative Stress; Oxidative Stress Induction; Pathogenesis; Pathway interactions; Patients; Phagocytosis; Phase; Phenotype; Play; Population; Process; Property; Regulation; Reporting; Research; Retina; Retinal Degeneration; Role; Sampling; Signal Transduction; Stimulator of Interferon Genes; Structure of retinal pigment epithelium; Testing; Tissues; Training; Up-Regulation; Vision; aged; bioinformatics tool; cytokine; experimental study; ezrin; immunological status; in vivo; induced pluripotent stem cell; inhibitor; macula; monocyte; mouse model; neutrophil; novel; novel therapeutics; overexpression; risk variant; single-cell RNA sequencing; tool

Project Summary: Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly and is driven by multiple genetic and environmental factors that lead to severe loss of central vision. However, no definitive treatment options are available for the dry form of the disease. Inflammation has been known to play an important role in maintaining tissue homeostasis. However, a deregulated inflammatory response is associated with tissue damage and the onset of several aging diseases, including AMD. Even though several studies have demonstrated the role of inflammation in AMD pathogenesis, the underlying mechanism controlling the inflammatory cascades, particularly driving the onset of chronic inflammation in AMD, still remains unknown. We have recently reported the novel finding that in dry AMD patients9,10 and in a mouse model of dry AMD, there is inflammation induction due to the activation of Akt2 signaling in the retinal pigment epithelial (RPE) cells-the first cells affected in dry AMD. Importantly, Akt2 inhibition in this mouse model reduced retinal inflammation and alleviated early RPE changes. Additionally, AMD patients also have increased Akt2 levels in the macular RPE cells relative to controls. Therefore, to evaluate the role of Akt2 activation in RPE health and in retinal degeneration, we have generated RPE-specific Best1 (Akt2) constitutive knock-in (KI) mice. These mice show a dry AMD-like phenotype, as evident from basal laminar deposits, decreased ezrin expression, hyperpigmentation, and morphological alterations in the RPE, as well as decreased retinal function. We propose to use this mouse model and iPSC-derived RPE from CFH(Y/Y) [controls] and CFH(H/H) [AMD risk allele containing] donors as novel tools in this study for testing our central hypothesis that “activation of Akt2 signaling in the RPE triggers mitochondrial/autophagy dysfunction leading to oxidative stress and inflammation, which are critical factors in early AMD pathogenesis”. To address this hypothesis, we propose the following aims: Specific Aim 1 (mentored phase): To test our hypothesis that Akt2 overexpression in the RPE elicits mitochondrial/mitophagy dysfunction thereby inducing oxidative stress; Specific Aim 2 (mentored phase): To test our hypothesis that activation of Akt2 in the RPE drives retinal inflammation; Specific Aim 3 (independent phase): To test our hypothesis that the molecular cascades associated with autophagy-mediated regulation of inflammation are critical in AMD pathogenesis. The proposed study is significant because we will use a unique, state-of-the-art in vivo animal model and extend our studies to human iPSC-derived RPE samples to investigate how inflammation contributes to vision loss in AMD and develop strategies potentially leading to a new treatment modality for early, dry AMD.

项目摘要：与年龄相关的黄斑变性（AMD）是较早失明的主要原因 并由多种遗传和环境因素驱动，导致中央视力严重丧失。然而， 该疾病的干燥形式没有明确的治疗选择。已知炎症已知 在维持组织稳态方面起着重要作用。但是，放松管制的炎症反应是 与组织损伤和包括AMD在内的几种衰老疾病的发作有关。即使几个 研究表明，炎症在AMD发病机理（潜在机制）中的作用 控制炎症性级联反应，特别是推动AMD中慢性炎症的发作 仍然未知。我们最近报道了新发现的发现，在干燥的AMD患者中9,10和小鼠中 干燥AMD的模型，由于残留色素中Akt2信号的激活而引起了注射诱导 上皮（RPE）细胞 - 在干燥AMD中受影响的第一细胞。重要的是，该小鼠模型中的AKT2抑制 减少了视网膜注射并减轻了早期RPE的变化。此外，AMD患者也有 相对于对照组，黄斑RPE细胞中的Akt2水平增加。因此，评估AKT2的作用 激活RPE健康和残留变性，我们产生了RPE特异性BEST1（AKT2）一致性 敲入（Ki）小鼠。这些小鼠显示出干燥的AMD状表型，这是从碱性层流沉积物中证明的， Ezrin的表达降低，色素沉着和RPE的形态学改变，以及 视网膜功能降低。我们建议使用CFH（Y/Y）使用此鼠标模型和IPSC衍生的RPE [对照]和CFH（H/h）[AMD风险含有等位基因]供体作为本研究的新工具，用于测试我们的中心 假设“ RPE中Akt2信号的激活触发线粒体/自噬功能障碍 导致氧化应激和炎症，这是早期AMD发病机理的关键因素。” 解决这个假设，我们提出以下目的：特定目标1（指导阶段）：测试我们的 RPE中的Akt2过表达引起线粒体/线粒体功能障碍的假设，从而诱导 氧化应激；特定目标2（指导阶段）：测试我们的假设，即RPE中Akt2的激活 驱动常规炎症；特定目标3（独立阶段）：测试我们的假设是分子 与自噬介导的炎症调节有关的级联对于AMD发病机理至关重要。 拟议的研究很重要，因为我们将使用独特的，最先进的体内动物模型和 将我们的研究扩展到人类IPSC衍生的RPE样本，以研究感染如何对视觉有效 AMD的损失并制定策略可能导致早期干燥AMD的新治疗方式。