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.

项目概述：老年性黄斑变性（AMD）是老年人致盲的主要原因 并且由导致中心视力严重丧失的多种遗传和环境因素驱动。然而，在这方面， 对于这种疾病的干燥形式，没有确定的治疗选择。众所周知，炎症 在维持组织内环境稳定中起重要作用。然而，失调的炎症反应是 与组织损伤和包括AMD在内的几种衰老疾病的发作相关。尽管几 研究已经证实了炎症在AMD发病机制中的作用， 控制炎症级联反应，特别是推动AMD慢性炎症的发生，仍然是 仍然未知。我们最近报道了一个新的发现，在干性AMD患者中9，10和小鼠中， 在干性AMD模型中，由于视网膜色素中Akt 2信号传导的激活，存在炎症诱导 上皮细胞（RPE）-干性AMD中受影响的第一个细胞。重要的是，该小鼠模型中的Akt 2抑制 减轻视网膜炎症和减轻早期RPE改变。此外，AMD患者还 相对于对照，黄斑RPE细胞中Akt 2水平增加。因此，要评估Akt 2的作用 在RPE健康和视网膜变性中的激活，我们已经产生了RPE特异性Best 1（Akt 2）组成型 敲入（KI）小鼠。这些小鼠表现出干型AMD样表型，从基底层沉积物可以看出， 减少ezrin表达，色素沉着过度，RPE形态学改变，以及 视网膜功能下降。我们建议使用该小鼠模型和来自CFH的iPSC衍生的RPE（Y/Y）。 [对照组]和CFH（H/H）[含AMD风险等位基因]供体作为本研究的新工具， 假设“RPE中Akt 2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发病机制中的关键因素”。到 针对这一假设，我们提出了以下目标：具体目标1（指导阶段）：为了测试我们的 假设RPE中Akt 2过表达可诱发线粒体/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）：为了验证我们的假设，即RPE中Akt 2的激活 驱动视网膜炎症;特异性目标3（独立期）：为了验证我们的假设， 与自噬介导的炎症调节相关的级联反应在AMD发病机制中至关重要。 这项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。 研究人员正在研究AMD的治疗方法，并开发可能导致早期干性AMD新治疗方式的策略。