Corneal Epithelial Differentiation and Regeneration

描述（申请人提供）：角膜上皮、间质和内皮的独特组织结构对角膜的形状、透明度和保护功能至关重要。物理、化学或感染性损伤可导致修复组织结构受损、功能不良或复发性愈合问题，通常需要角膜手术或移植。因此，我们希望了解这些细胞在正常发育和再生或修复过程中迁移、增殖和分化的基本机制。具体来说，我们关注的是这些关键、活跃过程的分子调控。我们之前的工作强烈暗示了小GTPase Rho及其下游靶激酶ROCK在调节角膜上皮增殖、细胞间通讯和角膜基质活化方面的作用。具体目的是针对测试一些非常合理的，但至关重要的，关于Rho信号参与这些过程的机制的假设。具体来说：1)Rho/ROCK信号通过调控细胞周期指导角膜上皮细胞增殖。2) Rho/ROCK信号通路在细胞周期进程中通过连接蛋白43间隙连接调节角膜上皮细胞间的通讯，进而直接影响间隙连接对细胞周期进程的调节。3)角膜基质细胞的活化和失活是由Rho/ROCK和Rho/mDial信号联合调控的。前两个目标将使用兔角膜上皮细胞，第三个目标将使用兔角膜基质细胞进行培养。这些假设的评估将促进我们对维持角膜稳态和伤口愈合的分子信号机制的认识。这些知识可能会导致调节细胞活化、细胞间通讯、分化和增殖的方法的发展，这对改善角膜伤口愈合的新干预措施至关重要。

DESCRIPTION (provided by applicant): The unique organization and structure of the corneal epithelium, stroma and endothelium are critical to the shape, transparency and protective functions of the cornea. Physical, chemical or infectious damage can result in repair tissues that have compromised structure, function poorly or have recurrent healing problems, often requiring corneal surgery or transplantation. Therefore, we wish to understand the basic mechanisms that regulate the migration, proliferation, and differentiation of these cells during normal development and during regeneration or repair. Specifically, we are focusing on the molecular regulation of these critical, active processes. Our previous work strongly implicates the small GTPase, Rho, and its downstream target kinase named ROCK in regulating corneal epithelial proliferation, cell-cell communication and corneal stromal activation. The Specific Aims are directed at testing some very reasonable, yet crucial, hypotheses about the mechanism of involvement of Rho signaling in these processes. Specifically: 1) Rho/ROCK signaling directs corneal epithelial proliferation, through regulation of the cell cycle. 2) Rho/ROCK signaling regulates corneal epithelial cell-cell communication via connexin 43 gap junctions during the cell cycle progression and, in turn, has direct effects on gap junctional regulation of cell cycle progression. 3) Corneal stromal cell activation and inactivation is controlled by conjoint Rho/ROCK and Rho/mDial signaling. The first two aims will employ rabbit corneal epithelial cells and the third aim employs rabbit corneal stromal cells, in culture. The evaluation of these hypotheses will advance our knowledge of the molecular signaling mechanisms that sustain corneal homeostasis and wound healing. That knowledge may lead to the development of methods for modulating cellular activation, cell-cell communication, differentiation and proliferation, which are critical to new interventions to improve corneal wound healing.