Mechanisms of corneal stromal activation during regeneration and fibrosis by exosomes

总结 已知角膜瘢痕形成（或纤维化）在中度至重度伤口中引起视力损害，并且没有 预防或治疗的单一有效疗法，需要新的工具来治疗和减少 疤痕的风险是紧迫的。细胞间通讯是角膜的重要组成部分， 体内平衡、再生和纤维化。我们已经表明，角膜的伤口愈合机制， 上皮细胞包含在其分泌组中，细胞外囊泡（EV）是关键载体。期间 在EV产生过程中，EV选择性地吞噬其亲本细胞的一部分，并变得富含一系列 生物活性货物（例如，蛋白质、脂质和RNA）。我们最近报道了人角膜成纤维细胞（hCF） 与TGF-β3不同，TGF-β1治疗增加了建立纤维化基质的纤维化标志物的表达， （抗纤维化）。此外，我们的数据表明，来自人角膜上皮细胞（hCE-EV）的EV可以 hCE-EV的蛋白质组含有TGF-β1或TGF-β3，可能是hCF分化的驱动因子。 这可能有助于角膜瘢痕形成的机制作用。尽管，尽管 hCE-EV的伤口愈合和角膜基质活化能力，我们对其生物活性的理解 这种作用的性质和分子机制仍不清楚。在本提案中，我们假设， EV亚群hCE（TGF-β 1 KD/-β 3 KD）-EV将触发角膜肌成纤维细胞分化，以产生一种细胞因子， 激活支持纤维化愈合的基质微环境。我们提出以下目标来检验这一点 假设：目的1）调节和表征hCE-EV亚群;目的2）定义 目的3）确定hCE-EV亚群如何影响角膜内皮细胞的生长， 体内结疤。与公共卫生的相关性-总的来说，该提案将为hCE提供重要的见解- EV生物学和角膜成纤维细胞-靶细胞相互作用，可用于开发新的基于EV的 预防和治疗角膜疤痕的疗法。

SUMMARY Corneal scarring (or fibrosis) is known to cause visual impairment in moderate to severe wounds, and with no single effective therapy for either the prevention or treatment, the need for new tools to treat and reduce the risk of scarring is urgent. Cell-cell communication is a vital component for the cornea that encompasses homeostasis, regeneration, and fibrosis. We have shown that the wound-healing mechanisms of corneal epithelial cells are comprised in their secretome, with extracellular vesicles (EVs) being a key vector. During EV production, the EVs selectively engulf a part of their parental cell and become enriched in a repertoire of bioactive cargo (e.g., proteins, lipids, and RNAs). We recently reported that human corneal fibroblasts (hCF) treated by TGF-β1 increased expression of fibrotic markers that established a fibrotic matrix, unlike TGF-β3 (anti-fibrotic). Also, our data suggests that EVs derived from human corneal epithelial cells (hCE-EV) can trigger hCF differentiation, and the proteome of hCE-EV containing TGF-β1 or -β3 could be a driving mechanism that could contribute to the mechanistic action of corneal scar formation. Although, despite the wound-healing and corneal stromal activation capacity of hCE-EVs, our understanding of their bioactive properties and molecular mechanisms for such effects remains unclear. In this proposal, we hypothesize that the EV subsets, hCE (TGF-β1KD/-β3KD)-EVs, will trigger corneal myofibroblast differentiation to generate an activated stromal microenvironment that supports fibrotic healing. We propose the following Aims to test this hypothesis: Aim 1) Modulate and characterize hCE-EV subsets; Aim 2) Define stromal activation capacity of hCE-EV subsets in 2D and 3D models in vitro; and Aim 3) Determine how hCE-EV subsets effect corneal scarring in vivo. Relevance to Public Health—Collectively, this proposal will provide important insight for hCE- EV biology and corneal fibroblast-target cell interaction, which can be leveraged to develop novel EV-based therapies for the prevention and treatment of corneal scarring.