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：年龄相关性黄斑变性（AMD）是老年人失明的主要原因 它是由多种遗传和环境因素驱动的，导致中央视力严重丧失。 目前还没有针对干性炎症的明确治疗方案。 在维持组织稳态中发挥重要作用，然而，炎症反应失调。 与组织损伤和多种衰老疾病（包括 AMD）的发生有关。 研究证明炎症在AMD发病机制中的作用，其潜在机制 控制炎症级联反应，特别是驱动 AMD 慢性炎症的发生，仍然 我们最近报道了在干性 AMD 患者9,10 和小鼠中的新发现。 干性 AMD 模型中，由于视网膜色素中 Akt2 信号的激活而诱导炎症 上皮 (RPE) 细胞——干性 AMD 中受影响的第一个细胞。重要的是，在该小鼠模型中，Akt2 受到抑制。 减少视网膜炎症并减轻早期 RPE 变化此外，AMD 患者也有这种情况。 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。 RPE 健康和视网膜变性中的激活，我们生成了 RPE 特异性 Best1 (Akt2) 本构 敲入 (KI) 小鼠显示出干性 AMD 样表型，从基底层状沉积物可以明显看出， ezrin 表达、色素沉着过度和 RPE 形态改变，以及减少 我们建议使用该小鼠模型和来自 CFH(Y/Y) 的 iPSC 衍生的 RPE。 [对照] 和 CFH(H/H) [含有 AMD 风险等位基因] 供体作为本研究中测试我们的中心的新工具 假设“RPE 中 Akt2 信号的激活会触发线粒体/自噬功能障碍” 导致氧化应激和炎症，这是早期 AMD 发病机制的关键因素”。 针对这一假设，我们提出以下目标： 具体目标 1（指导阶段）：测试我们的 假设 RPE 中 Akt2 过度表达会引发线粒体/线粒体自噬功能障碍，从而诱导 氧化应激；具体目标 2（指导阶段）：检验我们的假设，即 RPE 中 Akt2 的激活 驱动视网膜炎症；具体目标 3（独立阶段）：检验我们的假设，即分子 与自噬介导的炎症调节相关的级联在 AMD 发病机制中至关重要。 拟议的研究意义重大，因为我们将使用独特的、最先进的体内动物模型， 将我们的研究扩展到人类 iPSC 衍生的 RPE 样本，以研究炎症如何影响视力 AMD 的损失并制定可能为早期干性 AMD 带来新治疗方式的策略。