RPE Exosomes in Age-related Macular Degeneration

摘要 视网膜相关性黄斑变性（AMD）是老年人不可逆失明的主要原因， 在发达国家，治疗选择有限。最早的临床体征是脂质和蛋白质 称为玻璃疣的沉积物，其形成于视网膜色素上皮（RPE）和邻近的 五层胶原细胞外基质，布鲁赫膜。RPE的功能是保持外部 血-视网膜屏障和支持光感受器功能，包括视觉色素的再生， 外段的周转。RPE的功能障碍是导致AMD的病理基础。据认为，在 AMD这种RPE细胞的失调至少部分地导致玻璃疣的形成。目前该 玻璃疣形成的确切机制是未知的。一种检测早期AMD病理的潜在方法， 生物变化是通过分离外泌体，外泌体是可以从 生物流体（例如血浆和尿液）。由于RPE释放的外泌体和其他细胞外囊泡是必不可少的 部分的内体途径，我假设，从应激RPE细胞释放的外泌体， 这些外泌体与未应激的RPE细胞释放的外泌体不同，并且这些外泌体参与了视网膜色素上皮细胞的增殖。 特征性存款形成和ECM的变化是AMD早期和晚期的基础。通过 评估两种互补的体外和体内AMD模型，我们的目标是确定 在与AMD相关的条件下，RPE下存款形成和ECM变化中的外泌体分泌， 以及药理学或基因治疗/生物治疗干预是否可能。上 目的，我将表征和定量的蛋白质和脂质组成的亚RPE存款，ECM和基底- RPE中的侧外来体受到AMD所涉及的病理生理条件的应激（氧化应激， 补体失调和年龄），同时通过药理学和遗传学调节外泌体释放。 接近。在第二个目标中，我将分子标记，分离和表征RPE衍生的外泌体， 早期AMD的良好表征的小鼠模型的血液。RPE衍生的详细分析 在正常和患病环境中的外泌体代表了新的研究， 导致AMD的病理变化

Abstract Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the elderly in developed countries, and there are limited therapeutic options. The earliest clinical signs are lipid and protein deposits known as drusen, that form between the retinal pigmented epithelium (RPE) and the adjacent pentalaminar collagenous extracellular matrix, Bruch’s membrane. The RPE functions to maintain the outer blood-retinal barrier and to support photoreceptor function, including regeneration of visual pigment and turnover of outer segments. Dysfunction of the RPE underlies pathology leading to AMD. It is thought that in AMD this dysregulation in RPE cells is at least in part responsible for the formation of drusen. At present, the exact mechanisms for drusen formation are unknown. A potential approach to detect early AMD patho- biological changes is through the isolation of exosomes, which are nanovesicles that can be purified from biofluids (e.g. plasma and urine). Since RPE-released exosomes and other extracellular vesicles are essential parts of the endosomal pathway, I hypothesize that exosomes released from stressed RPE cells are distinct from those released from unstressed RPE cells, and that these exosomes are involved in the pathognomonic deposit formation and ECM changes that underlie the early and late stages of AMD. By evaluating two complementary in vitro and in vivo AMD models, our goal for this project is to determine the role of exosome secretion in sub-RPE deposit formation and in ECM changes under conditions relevant to AMD, and whether pharmacological or gene therapy/biological therapeutic interventions are possible. In the first aim, I will characterize and quantify the protein and lipid composition of sub-RPE deposits, ECM and basal- side exosomes in RPE stressed by pathophysiological conditions implicated in AMD (oxidative stress, complement dysregulation, and age), while modulating exosome release by both pharmacological and genetic approaches. In the second aim, I will molecularly tag, isolate and characterize RPE-derived exosomes from the blood of a well characterized mouse model of early-stage AMD. Detailed profiling of RPE-derived exosomes in normal and diseased settings represent novel studies that will provide insight into mechanisms that underlie pathobiological changes in AMD.