Assessing the effects of extracellular vesicles on a human in vitro dry AMD model

老年性黄斑变性(AMD)是老年人致盲的主要原因，分为干性和湿性两种类型。在AMD的病理过程中，除了黄斑部感光锥光感受器的丧失外，视网膜色素上皮(RPE)也受到严重影响。虽然临床上已经建立了针对湿性AMD的抗血管内皮生长因子疗法，以抑制有害的血管生长，但目前还没有有效的治疗方法可用于干性AMD。虽然RPE替代疗法在晚期AMD的临床试验中得到了检验，但这种方法的特点是与安全性、移植生产和成本相关的挑战。因此，开发替代的治疗方法，特别是在疾病早期阶段进行干预，具有很高的临床需求。细胞外小泡(EVS)是一种无细胞系统，目前被研究用于输送治疗分子和预防多种疾病的病理情况，因此也代表了一种潜在的治疗AMD的选择。EV参与生理和病理的细胞间通讯，其产生和分泌是有针对性的，它们可以通过包括miRNAs在内的不同成分激活或抑制其靶细胞内的特定信号通路。miRNAs是一类复杂的基因调控RNA分子。事实上，EV已经在健康和患病的视网膜中被发现，它们在不同类型的细胞之间传递生物信号。在这项研究中，我们旨在通过(I)将我们建立的氧化应激模型应用于人IPSC来源的RPE细胞作为干性AMD的模型，(Ii)分离和鉴定RPE来源的EV，(Iii)评估RPE-EV对应激的人RPE细胞的拯救潜力，以及(Iv)利用RNA图谱和生物信息学分析来鉴定和评估RPE-EV中潜在的治疗成分，并研究已确定的miRNAs对应激RPE细胞的影响，以评估RPE来源的EVS对RPE损伤的体外模型的影响。这项研究的结果将确定EVS和miRNAs对受损的RPE细胞的治疗效果，作为治疗干性AMD的潜在新选择。

Age related macular degeneration (AMD) is the leading cause for blindness in the elderly population and is classified into two forms of dry and wet AMD. Besides the loss of the light-sensing cone photoreceptors in the macula also the underlying retinal pigment epithelium (RPE) is severely affected in AMD pathology. While anti-VEGF therapies have been clinically established for wet AMD to inhibit detrimental vessel growth, no effective treatment is currently available for dry AMD. Though RPE replacement therapies are examined in clinical trials for late stage AMD, such approaches are characterized by challenges related to safety, transplant production, and costs. Thus, the development of alternative therapeutic approaches, particularly interfering at early disease stages, is of high clinical need. Extracellular vesicles (EVs) represent a cell free system that is currently investigated for the delivery of therapeutic molecules and prevention of pathological conditions in several diseases, thus representing a potential therapeutic treatment option also for AMD. EVs are involved in physiological and pathological cell-cell communication, their production and secretion is targeted, and they can activate or inhibit specific signalling pathways inside their target cells via different components including miRNAs, a class of complex gene regulatory RNA molecules. Indeed, EVs have been identified in the healthy and diseased retina, where they transferred biological signals between different cell types. In this study, we aim to assess the effects of human RPE-derived EVs on an in vitro model of RPE damage by (i) adapting our established oxidative stress model to human iPSC-derived RPE cells as a model of dry AMD, (ii) isolating and characterizing RPE-derived EVs, (iii) assessing the rescue potential of RPE-EVs on stressed human RPE cells, and (iv) identifying and evaluating potential therapeutic components within RPE-EVs using RNA profiling and bioinformatics analysis, and investigating the effects of identified miRNAs on stressed RPE cells. The results of this study will determine the therapeutic effect of EVs and miRNAs on damaged RPE cells as potential novel options for the treatment of dry AMD.