AMPK/SIRT1/PGC-1α, a critical pathway in dry AMD

AMPK/SIRT1/PGC-1α，干性 AMD 的关键途径

• 批准号: 10355656
• 负责人: Nady Golestaneh
• 金额: $ 4.13万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10355656
• 关键词: 5' -AMP-activated protein kinase; Address; Affect; Age; Age related macular degeneration; Animal Model; Autophagocytosis; Biogenesis; Blindness; Bruch' s basal membrane structure; Cell Death; Cell Line; Cell Respiration; Cells; Critical Pathways; Data; Deacetylase; Deacetylation; Deposition; Development; Diet; Disease; Disease model; Drug Screening; Drusen; Elderly; Exhibits; Eye; Fibroblasts; Functional disorder; Generations; Glycogen; Health; High Fat Diet; Homeostasis; Impairment; In Vitro; Laboratories; Lipids; Lipofuscin; Medical; Metabolic; Mitochondria; Modeling; Molecular; Mus; Neurodegenerative Disorders; Nonexudative age-related macular degeneration; Organelles; Outcome; Oxidative Stress; PPAR gamma; Pathology; Pathway interactions; Patients; Phenotype; Phosphorylation; Play; Predisposition; Production; Protein Kinase; Proteins; Quality of life; Reactive Oxygen Species; Repression; Research; Retina; Retinal Diseases; Role; SIRT1 gene; Secondary to; Signal Transduction; Skin; Structure of retinal pigment epithelium; Testing; Therapeutic Intervention; Visual system structure; base; disease diagnosis; disease phenotype; effective therapy; in vitro Model; in vivo; induced pluripotent stem cell; insight; mitochondrial dysfunction; mouse model; novel; novel therapeutic intervention; novel therapeutics; photoreceptor degeneration; receptor; retinal progenitor cell; treatment strategy

ABSTRACT Age-related macular degeneration (AMD) is the major cause of blindness in people over age 55 in the U.S. and the developed world. One of the two forms of AMD is the “dry” form, for which currently there are no effective treatments. Consequently, there is an unmet medical need for the development of new therapies for AMD. A number of retinal diseases, including AMD, are associated with mitochondrial dysfunction. Dysfunctional mitochondria induce increased levels of reactive oxygen species (ROS) and defective metabolic activity. Autophagy loss also results in mitochondrial dysfunction and is suggested to increase susceptibility to oxidative stress and AMD. We have recently shown dysfunctional autophagy, increased ROS, and dysfunctional mitochondria in RPE derived from AMD donor eyes. However, the underlying mechanisms inducing these defective metabolic homeostases leading to AMD remain unknown. The Peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1alpha (PGC-1) plays a major role in mitochondrial biogenesis and oxidative metabolism. It also regulates autophagy and mitophagy. PGC-1 activity is stimulated by two main factors: AMP-activated protein kinase (AMPK) and NAD+ - dependent deacetylase, SIRT1. Preliminary evidence from our laboratory suggests that the AMPK/SIRT1/PGC-1 is downregulated in AMD RPE. Based on our preliminary data, we hypothesize that the repressed AMPK/SIRT1/PGC-1 pathway in RPE induces mitochondrial, autophagic dysfunction, and increased ROS production, which results in abnormal metabolic activity, lipid and glycogen accumulation, and drusen formation, leading to the AMD pathophysiology. To test our hypothesis, we have developed an inexhaustible AMD in vitro disease model by isolating native RPE from AMD donors’ eyes, followed by the generation of iPSC and their subsequent differentiation into RPE (AMD RPE- iPSC-RPE). We have also generated iPSC from RPE of age-matched normal donors (Normal RPE-iPSC-RPE) that serve as the control. We confirmed that the AMD RPE-iPSC-RPE mimic the disease phenotypes of their parental donors, the primary AMD RPE, which validates our model. Additionally, we established an animal model to test the role of PGC-1 repression on RPE and retinal health and observed RPE and photoreceptor degeneration. We propose two aims: Aim1 will test the role of AMPK/SIRT-1/PGC-1 pathway inhibition in dry AMD using our established in vitro model from AMD donors and AMD patients. Aim2 will investigate the cellular and molecular mechanisms of PGC-1 actions on RPE and retinal health in a mouse model. Ultimately, these studies will provide insight into the molecular mechanisms of dry AMD and may facilitate new therapeutic interventions.

摘要 视网膜相关性黄斑变性（AMD）是美国55岁以上人群失明的主要原因， 发达国家。AMD的两种形式之一是“干燥”形式，目前还没有有效的治疗方法。 治疗。因此，对于开发用于AMD的新疗法存在未满足的医学需求。一 许多视网膜疾病，包括AMD，与线粒体功能障碍有关。功能失调 线粒体诱导活性氧（ROS）水平增加和代谢活性缺陷。 自噬丧失也导致线粒体功能障碍，并被认为增加了对氧化应激的敏感性。 压力和AMD。我们最近发现了功能失调的自噬，增加的ROS，以及功能失调的自噬。 来自AMD供体眼睛的RPE中的线粒体。然而，诱导这些的潜在机制 导致AMD的代谢稳态缺陷仍然未知。过氧化物酶体增殖物激活 受体-γ辅激活因子（PGC）-1 α（PGC-1 α）在线粒体生物发生中起主要作用， 氧化代谢它还调节自噬和线粒体自噬。PGC-1 β活性由两种主要的 因子：AMP活化蛋白激酶（AMPK）和NAD+依赖性脱乙酰酶，SIRT 1。初步证据 提示AMPK/SIRT 1/PGC-1在AMD RPE中下调。基于我们 根据初步数据，我们假设RPE中被抑制的AMPK/SIRT 1/PGC-1 β通路诱导 线粒体，自噬功能障碍和ROS产生增加，导致代谢异常， 活性、脂质和糖原积累以及玻璃疣形成，导致AMD病理生理学。测试 根据我们的假设，我们已经开发了一种取之不尽的AMD体外疾病模型， AMD供体的眼睛，随后产生iPSC并随后分化成RPE（AMDRPE-1）。 iPSC-RPE）。我们还从年龄匹配的正常供体的RPE产生了iPSC（正常RPE-iPSC-RPE）。 作为对照。我们证实了AMD RPE-iPSC-RPE模拟了他们的疾病表型。 父母捐赠者，主要的AMD RPE，这验证了我们的模型。此外，我们建立了一种动物模型， 检测PGC-1 β抑制对RPE和视网膜健康的作用，并观察RPE和感光细胞 退化我们提出了两个目标：Aim 1将测试AMPK/SIRT-1/PGC-1 β通路抑制在干细胞中的作用。 AMD使用我们建立的AMD供体和AMD患者的体外模型。aim 2将调查细胞 和小鼠模型中PGC-1对RPE和视网膜健康的抑制作用的分子机制。最终，这些 这些研究将深入了解干性AMD的分子机制， 干预措施。