Elucidating the Molecular Underpinnings of Endogenous RPE Regeneration

阐明内源性 RPE 再生的分子基础

基本信息

批准号：
10646447
负责人：
Jeffrey Gross
金额：
$ 31.62万
依托单位：
UNIVERSITY OF TEXAS AT AUSTIN
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-06-01 至 2025-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10646447
关键词：
Ablation Adult Affect Age related macular degeneration Animal Model Atrophic Biological Models Blindness Cells Clinical Trials Data Development Disease Dryness Environment Epithelial Cell Proliferation Eye Foundations Genes Genetic Human Immune Immune response In Vitro Injury Innate Immune Response Innate Immune System Invaded Knowledge Lesion Mammals Mesenchymal Modeling Molecular Morphology Natural regeneration Organ Model Pathologic Pathway interactions Peripheral Play Population Process Proliferating Proliferative Vitreoretinopathy Regenerative response Retina Retinal Degeneration Role Signal Transduction Site Source Stem cell transplant Structure of retinal pigment epithelium System Testing Therapeutic Tissue Model Tissues Traction Transgenic Organisms Vision Zebrafish candidate identification cell regeneration cell type effective therapy epithelial injury epithelial stem cell epithelium regeneration experimental study geographic atrophy imaging approach immunoregulation improved in vivo innovation monolayer pharmacologic regenerative regenerative approach regenerative cell repaired response response to injury retina transplantation retinal regeneration severe injury therapy development tissue regeneration transcriptome sequencing

项目摘要

SUMMARY: Diseases resulting in degeneration of the retinal pigment epithelium (RPE) are among the leading causes of blindness worldwide and no therapy exists that can replace RPE or restore lost vision. Age-related macular degeneration (AMD) is one such disease and is the third leading cause of blindness in the world. While there are some effective treatments for exudative (wet) AMD, ~90% of AMD cases are atrophic (dry) and these are currently untreatable. Transplantation of stem-cell derived RPE has emerged as a possibility for treating geographic atrophy and clinical trials are underway. However, little is known about the fate of transplanted RPE and whether their survival and integration can be improved. An intriguing alternative approach to treating AMD and other RPE diseases is to develop therapies focused on stimulating endogenous RPE regeneration. For this to be possible, we must first gain a deeper understanding of the mechanisms underlying RPE regeneration. In mammals, RPE regeneration is extremely limited and in some contexts RPE cells overproliferate after injury, such as during proliferative vitreoretinopathy, where proliferative RPE cells invade the subretinal space and lead to blindness. Recently, a subpopulation of quiescent human RPE stem cells was identified that can be induced to proliferate in vitro and differentiate into RPE or mesenchymal cell types, suggesting that the human RPE contains a population of cells that could be induced to regenerate. Despite these studies, little is known about the process by which RPE cells respond to injury to elicit a regenerative, rather than pathological, response. Indeed, no studies have demonstrated regeneration of a functional RPE monolayer following severe RPE damage in any model system. The development of such a model is a critical first step to acquiring a deeper understanding of the molecular mechanisms underlying RPE regeneration. This knowledge gap is a major barrier to developing effective strategies to restore RPE lost to disease or injury and is the focus of our proposal. We developed a transgenic zebrafish model to study RPE injury and regeneration and demonstrate that the zebrafish RPE regenerates after severe injury. We further demonstrate i) that RPE regeneration involves a robust proliferative response during which proliferative cells move to the injury site and differentiate into RPE, ii) that the source of regenerated cells is likely uninjured peripheral RPE, iii) using this system, we can identify the molecular underpinnings of the regenerative response, and iv) the innate immune system plays a critical role in RPE regeneration. Experiments in this proposal build off of these strong preliminary data to test the hypothesis that RPE regeneration is effected by a population of injury-activated resident RPE cells that proliferate upon injury and regenerate lost RPE tissue. Understanding how injury-responsive RPE cells proliferate in vivo and the signals/pathways active during the injury response holds significant promise to identify strategies to stimulate or reactivate this ability in the human eye, which would be transformational for treating AMD and other diseases that affect the RPE.

摘要：导致视网膜色素上皮（RPE）变性的疾病是领先的世界范围内失明的原因，没有任何可以取代RPE或恢复失去视力的疗法。与年龄有关黄斑变性（AMD）就是一种这样的疾病，是世界上失明的第三大主要原因。虽然有一些有效的渗出性（湿）AMD治疗方法，但约90％的AMD病例是萎缩（干）和这些目前是不可处理的。 Stem-Cell派生的RPE的移植已成为可能的可能性治疗地理萎缩和临床试验正在进行中。但是，关于命运知之甚少移植的RPE及其生存和整合是否可以改善。一个有趣的选择治疗AMD和其他RPE疾病的方法是开发针对刺激内源性的疗法 RPE再生。为此，我们必须首先对机制有更深入的了解基础RPE再生。在哺乳动物中，RPE再生非常有限，在某些情况下RPE 损伤后的细胞过度增殖，例如在增殖性玻璃体肾上腺病期间，其中增殖性RPE细胞入侵视网膜下空间并导致失明。最近，静态人RPE茎的亚群鉴定出可以诱导的细胞在体外增殖并分化为RPE或间充质细胞类型，表明人RPE包含可引起再生的细胞群。尽管进行了这些研究，但对RPE细胞对损伤的反应引起的过程知之甚少再生而不是病理反应。确实，没有研究表明在任何模型系统中，功能性RPE单层均发生严重RPE损伤。这样的发展模型是获得对RPE基础的分子机制的更深入了解的关键第一步再生。这种知识差距是制定有效策略以恢复RPE的主要障碍疾病或伤害，是我们提议的重点。我们开发了一个转基因斑马鱼模型来研究RPE 损伤和再生表明斑马鱼RPE在严重受伤后再生。我们进一步证明i）RPE再生涉及强大的增殖反应，在此涉及增殖细胞移至伤害部位并分化为RPE，ii）可能没有受伤的再生细胞来源外围RPE，iii）使用此系统，我们可以识别再生的分子基础反应，iv）先天免疫系统在RPE再生中起关键作用。实验提案建立在这些强大的初步数据的基础上，以检验RPE再生的假设损伤激活的居民RPE细胞的种群在损伤后增殖并再生RPE组织损失。了解损伤反应性RPE细胞如何在体内增殖和信号/途径在伤害反应具有巨大的希望，可以识别刺激或重新激活人类能力的策略眼睛，这将是治疗AMD和其他影响RPE的疾病的转变。