Extracellular vesicles from endothelial colony forming cells as paracrine mediators of neurovasculotrophic repair of the retina

项目摘要/摘要： 目前治疗缺血性视网膜病变的方法是抑制晚期血管渗漏和增殖。 疾病，但不针对导致病理性新生血管的缺血和/或炎症。一个 有希望的替代方法是刺激功能性、生理性血管的生长和稳定。一个 称为内皮集落形成细胞(ECFCs)的内皮祖细胞亚群可以促进这一过程。在……里面 小鼠缺血性视网膜病变模型(氧诱导视网膜病变，OIR)，ECFCs提供了显著的 血管和神经营养的挽救作用。有几条证据，包括我们实验室发表的发现， 证明这种治疗作用是通过旁分泌作用来实现的。然而，这件事的细节 机制仍未确定。 从ECFC中脱落的含有microRNA的胞外小泡(EV)最近被发现是重复性的 这种救援效果在OIR模型中。ECFC来源的EV促进内皮细胞迁移并增加 血管生成相关基因的表达。弗里德兰德实验室已经证明，ECFC的一个子集 以表面标志CD44(CD44hi)的高表达为特征，显示出更强健的血管-和 在OIR模型中CD44低表达的ECFC通过旁分泌的神经营养拯救作用 机制。根据这些数据，这项建议的首要假设是 CD44hi ECFC至少部分归因于由此释放的电动汽车中具有生物活性的microRNA(MiR)货物 ECFC亚群。我建议调查从CD44hi ECFC脱落的电动汽车中哪些miR上调 以确定与ECFC EVS的神经血管营养作用相关的新的MIR。电动汽车将 然后被设计成增加这些候选miR的表达，目标是重新设计治疗方案 在OIR模型中取得更好的治疗效果。 作为MIR的天然载体，电动汽车可能是一种高效的药物输送工具，可以规避 肿瘤发生与基于细胞的治疗相关。来自ECFC的电动汽车是 缺血/血管生成，潜在地限制了全身分娩的任何有害副作用。然而，一个更大的 了解电动汽车的异质种群及其货物和功能之间的关系 在转化为临床之前，必须开发出效果。

Project Summary/Abstract: Current treatments for ischemic retinopathies are designed to inhibit vascular leakage and proliferation in late disease, but do not target the ischemia and/or inflammation driving pathological neovascularization. A promising alternative approach is the stimulation of functional, physiologic vascular growth and stability. A subset of endothelial progenitor cells called endothelial colony forming cells (ECFCs) can facilitate this. In mouse models of ischemic retinopathy (oxygen-induced retinopathy, OIR), ECFCs provide a significant vasculo- and neurotrophic rescue effect. Several lines of evidence, including published findings from our lab, demonstrate this therapeutic effect to be mediated via paracrine action. However, the details of this mechanism remain uncharacterized. MicroRNA-containing extracellular vesicles (EVs) shed from ECFCs were recently discovered to recapitulate this rescue effect in the OIR model. ECFC-derived EVs promote endothelial cell migration and increase the expression of angiogenesis-related genes. The Friedlander lab has demonstrated that a subset of ECFCs characterized by high expression of the surface marker CD44 (CD44hi) exhibit a more robust vasculo- and neurotrophic rescue effect than ECFCs with low CD44 expression in the OIR model via a paracrine mechanism. In light of these data, the overarching hypothesis of this proposal is that the superior effect of CD44hi ECFCs is attributable, at least in part, to the bioactive microRNA (miR) cargo in EVs released from this ECFC subpopulation. I propose to investigate which miRs are upregulated in EVs shed from CD44hi ECFCs in order to identify novel miRs responsible for the reported neurovasculotrophic effects of ECFC EVs. EVs will then be engineered to increase expression of these candidate miRs with the goal of re-designing therapies that achieve even greater therapeutic effects in the OIR model. As natural carriers of miRs, EVs may be a highly effective drug delivery vehicle that circumvents the risks of tumorigenesis associated with cell-based therapeutics. ECFC-derived EVs home to sites of ischemia/angiogenesis, potentially limiting any deleterious side effects of systemic delivery. However, a greater understanding of heterogeneous populations of EV and the relationship between their cargo and functional effects must be developed before translation into the clinic can become a reality.