Mechanisms of RPE dysfunction in macular degenerations-DEIA Supplement

黄斑变性中 RPE 功能障碍的机制-DEIA 补充品

• 批准号: 10606306
• 负责人: Aparna Lakkaraju
• 金额: $ 35.97万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10606306
• 关键词: ATP binding cassette transporter 1; Age related macular degeneration; Atrophic; Autophagocytosis; Biogenesis; Blindness; Cell physiology; Cells; Ceramides; Cholesterol; Chronic; Complement; Complement 3a; Complement Activation; Data; Defect; Development; Disease; Disease model; Drusen; Early Endosome; Equilibrium; Extracellular Space; FRAP1 gene; Functional disorder; Generations; Genes; Genetic Polymorphism; Health; Homeostasis; Human; Image; Inflammation; Inflammatory; Inherited; Injury; Link; Lipofuscin; Location; Macular degeneration; Mediating; Metabolic; Metabolism; Mitochondria; Modeling; Molecular; Mus; Natural Immunity; Pathogenicity; Pathologic; Pathology; Pathway interactions; Peptide Hydrolases; Play; Precision therapeutics; Process; Proteolysis; Receptor Inhibition; Receptor Signaling; Recycling; Research; Resolution; Retina; Retinal Degeneration; Retinal Diseases; Role; Secondary to; Signal Transduction; Site; Speed; Stress; Structure of retinal pigment epithelium; Therapeutic; Therapeutic Intervention; Vision; base; cholesterol transporters; complement pathway; complement system; design; extracellular; innovation; insight; live cell imaging; mouse model; novel; photoreceptor degeneration; preservation; prevent; receptor; segregation; therapeutic target; trafficking; uptake

The complement system controls the balance between homeostatic and inflammatory processes. Although abnormal complement activity is strongly associated with macular degenerations, inhibiting this pathway has been unsuccessful in halting vision loss. To date, therapeutic approaches have focused on complete inhibition of extracellular complement activity, with limited insight into how complement proteins modulate retinal health and disease. This is particularly evident in approaches targeting the complement protein C3, the core effector molecule of the complement system, which plays context-dependent roles in the retina. Countering the conventional view of C3 acting solely in the extracellular space, recent studies from our group have identified intracellular C3 activation as a novel mechanism that modulates health of the retinal pigment epithelium (RPE), a primary site of injury in macular degenerations. In stressed or diseased RPE, increased uptake and proteolysis of C3 generates biologically active C3a (“intracellular C3 activation”). C3a in turn activates mTOR, a master regulator of cell health. Chronic mTOR activation is detrimental to cell health because it can reprogram cellular metabolism and cell fate decisions. Based on these exciting studies, we hypothesize that abnormal intracellular complement activation could drive disease pathology by compromising RPE homeostasis. We propose to molecularly dissect the machinery, mechanisms, and consequences of dysregulated intracellular C3a activity in the RPE, and identify potential points of therapeutic intervention to halt this cascade. We will identify the cellular machinery responsible for increased intracellular C3a generation in diseased RPE (Aim 1); investigate the dynamics of C3a signaling via its cognate receptor C3aR (Aim 2); and determine how persistent C3a-C3aR signaling disrupts RPE homeostasis and retinal function (Aim 3). We will use our expertise in innovative high- speed and super-resolution live-cell imaging and mouse models of disease to gain unprecedented spatial and temporal information about intracellular C3 activation and its consequences for retinal health. These studies will aid the development of a unified model that links multiple features of AMD, including cholesterol accumulation, complement activation, metabolic deficits and RPE dedifferentiation. Identifying molecular mechanisms that underlie increased intracellular C3 activation will aid the design of precision therapeutics to safeguard RPE health and retinal function over a lifetime.

完成系统控制体内平衡和炎症过程之间的平衡。虽然 异常补体活性与黄斑变性密切相关，抑制此途径 在停止视力丧失方面没有成功。迄今为止，治疗方法集中于完全抑制 细胞外补体活动，对完整蛋白如何调节常规健康的洞察力有限 和疾病。这是针对补体蛋白C3（核心效应子）的方法中特别的证据 完成系统的分子，在视网膜中扮演上下文依赖性角色。反击 C3的常规视图仅在细胞外空间中起作用，我们小组的最新研究已经确定 细胞内C3激活作为一种新机制，可调节视网膜色素上皮（RPE）的健康状况， 黄斑变性的主要损伤部位。在压力或解散的RPE中，摄取和蛋白水解增加 C3的生成生物活性C3a（“细胞内C3激活”）。 C3A依次激活MTOR（主人） 细胞健康调节剂。慢性MTOR激活对细胞健康有害，因为它可以重新编程 代谢和细胞脂肪决策。基于这些令人兴奋的研究，我们假设细胞内异常 补体激活可以通过折衷RPE稳态来促进疾病病理。我们建议 分子剖析失调的细胞内C3A活性的机制，机制和后果 RPE，并确定热干预的潜在点，以阻止此级联反应。我们将确定细胞 负责增加细胞内C3A生成的机械RPE（AIM 1）；调查 C3a信号通过其同源受体C3AR的动力学（AIM 2）；并确定持续的C3A-C3AR 信号传导破坏了RPE稳态和视网膜功能（AIM 3）。我们将使用我们的专业知识在创新的高中 速度和超分辨率的活细胞成像和疾病的小鼠模型，以获得前所未有的空间和 有关细胞内C3激活及其对永久健康的后果的临时信息。这些研究会 帮助开发统一模型，该模型将AMD的多个特征链接起来，包括胆固醇的积累， 补体激活，代谢定义和RPE去分化。识别分子机制 基础增加了细胞内C3激活将有助于设计精确疗法以保护RPE健康 和视网膜功能一生。