Regulation of Corneal Repair by Metalloproteinases

项目总结 角膜混浊影响着数百万人，是世界上第二大致盲原因。这个 威胁视力的角膜混浊的有效治疗是临床上尚未解决的主要挑战。 损伤是角膜混浊的主要原因，可通过多种机制发生，包括感染性 和非感染性溃疡，切开和激光手术，以及创伤。损伤后，蛋白酶调节 修复过程的各个方面，包括炎症、新生血管和重塑。过份 蛋白分解导致的角膜瘢痕形成与角膜透明度的丧失有关。《矩阵》 金属蛋白酶(MMPs)是与角膜创伤相关的最重要的蛋白家族。 在人类身上进行修复。长期以来，人们认识到角膜术后的组织破坏和角膜病理 损伤与MMPs介导的过度蛋白分解活性有关。然而，潜在的保护作用 修复反应中的基质金属蛋白被低估了。 我们已经发现MMP12(巨噬细胞金属弹性酶)在损伤的角膜中表达，并且有一个 伤口修复过程中对角膜纤维化的保护作用。我们的初步数据显示，MMP12可以保护 对抗角膜基质肌成纤维细胞转化，MMP12钝化角膜新生血管反应 MMP12通过调节VEGFA的表达抑制巨噬细胞的聚集 通过调节CCL2的表达来损伤角膜。总体而言，这些数据表明了 MMP12在角膜损伤的纤维化、新生血管和炎症反应中的作用。此外，我们的发现 提示MMP12是损伤后维持角膜透明度所需的重要因素。 鉴于这些发现，我们假设MMP12对CCL2表达的调节是一种常见的机制，通过 其中MMP12抑制炎症和新生血管。这一假设将在 实验的具体目的如下：(1)明确MMP12在调控MMP12基因表达中的作用 CCL2和CCR2；(2)确定MMP12和CCL2在角膜调节中的相互作用 (3)研究患者角膜样本中MMP12的表达和活性水平。 这种分子和翻译方法的结合将通过以下方式提供对机制的新见解 哪种MMP12可以预防角膜纤维化，并将为开发新的模式打开可能性 旨在防治人类患者的病理性纤维化。

PROJECT SUMMARY Corneal opacification affects millions of people and is the second leading cause of blindness in the world. The effective medical treatment of vision-threatening corneal opacification is a major unmet clinical challenge. Injury is a major cause of corneal opacification and can occur by a variety of mechanisms including infectious and noninfectious ulcers, incisional and laser surgery, and trauma. Following injury, proteinases regulate aspects of the repair process including inflammation, neovascularization, and remodeling. Excessive proteolysis resulting in corneal scarring has been associated with loss of corneal clarity. The matrix metalloproteinases (MMPs) represent the most prominent family of proteinases associated with corneal wound repair in humans. It has long been appreciated that tissue destruction and corneal pathology following corneal injury is associated with excessive proteolytic activity mediated by MMPs. However, potential protective effects of MMPs in the repair response are underappreciated. We have found that MMP12 (macrophage metalloelastase) is expressed in injured corneas and has a protective effect on corneal fibrosis during wound repair. Our preliminary data show that MMP12 protects against corneal stromal myofibroblast transformation, that MMP12 blunts the corneal angiogenic response to injury via regulation of VEGFA expression, and that MMP12 inhibits the accumulation of macrophages in wounded corneas via regulation of CCL2 expression. Collectively, these data demonstrate a protective role of MMP12 in the fibrotic, neovascular, and inflammatory responses to corneal injury. Furthermore, our findings suggest MMP12 as an important factor needed for the maintenance of corneal clarity following injury. Given these findings, we hypothesize that MMP12 regulation of CCL2 expression is a common mechanism by which MMP12 inhibits inflammation and neovascularization. This hypothesis will be addressed in the experiments of the following Specific Aims: (1) to define the role of MMP12 in the regulation of expression of CCL2 and CCR2; (2) to determine the interplay of MMP12 and CCL2 in the regulation of corneal neovascularization; and (3) to characterize MMP12 expression and activity levels in patient corneal samples. This combination of molecular and translational approaches will provide novel insight into the mechanisms by which MMP12 protects against corneal fibrosis and will open the possibility of developing novel modalities aimed at preventing and treating pathological fibrosis in human patients.