Intercellular Communication in the Eye Lens

描述(申请人提供)：连接蛋白形成的缝隙连接对维持眼晶状体的代谢稳态是必不可少的。我们和其他人最近发现了晶状体连接蛋白的一个新特征，它被发现在功能上参与促进上皮纤维分化和晶状体发育。我们的长期目标是了解缝隙连接及其组成部分--缝隙连接蛋白在晶状体发育和内稳态中的调节机制和功能意义。本应用的目的是了解Cx45.6在细胞分化和晶状体生长发育中的作用机制。核心假设是Cx45.6与其他两种类型的晶状体连接蛋白不同，它在功能上参与了晶状体分化过程和成熟晶状体纤维的形成。这一假说是基于我们的重要初步发现提出的，这些发现表明Cx45.6的表达促进了晶状体上皮-纤维分化，并且Cx45.6受积极参与晶状体终末分化的caspase-3的翻译后调控。具体目标有三个：1)。确定Cx45.6表达在晶状体上皮纤维分化和晶状体发育中的功能参与；确定Cx45.6分子的功能结构域(S)对晶状体分化的刺激作用，并表征Cx45.6与丝裂原蛋白和其他潜在因子的相互作用(S)。确定caspase-3介导的Cx45.6裂解的功能意义。其中一个创新方面是，这项提议旨在剖析晶状体连接蛋白非传统功能的机制。此外，研究计划将使用我们建立的禽类逆转录病毒方法作为主要工具，用于原代鸡晶状体培养和活体鸡晶状体的实验操作。我们期望我们的实验结果将为理解Cx45.6在分化晶状体纤维中的功能和调控提供分子基础，并对确定缝隙连接如何参与晶状体生长和发育具有重大影响。我们的研究结果将是重要的，因为新发现的知识将有助于更广泛地了解缝隙连接和连接蛋白在细胞分化和组织发育中的作用。此外，这一研究活动将为白内障等眼科疾病的治疗策略做出贡献，并为药物发现和开发的潜在靶点提供新的思路。

DESCRIPTION (provided by applicant): Gap junctions formed by connexins are known to be essential for maintaining metabolic homeostasis of eye lens. We as well as others have recently revealed a novel feature of the lens connexin, which was found to be functionally involved in promoting epithelial-fiber differentiation and lens development. Our long-range goal is to understand the regulatory mechanisms and functional significance of gap junctions and their component, connexins in lens development and homeostasis. The objective of this application is to understand the mechanistic roles of Cx45.6 in cell differentiation, and in lens growth and development. The central hypothesis is that Cx45.6, unlike two other types of lens connexins, is functionally involved in the differentiation process and the formation of mature lens fibers. This hypothesis has been formulated on the basis of our significant preliminary findings, which demonstrate that Cx45.6 expression enhances lens epithelial-fiber differentiation and Cx45.6 is posttranslationally regulated by caspase-3 that is actively involved in terminal lens differentiation. Three specific aims will be pursued: 1). Determine the functional involvement of Cx45.6 expression in epithelial-fiber differentiation and lens development; 2). Identify functional domain(s) of the Cx45.6 molecule important for the stimulatory effect on lens differentiation and characterize the interactions between Cx45.6 and MIP, and other potential factor(s), and 3). Determine the functional significance of caspase-3-mediated cleavage of Cx45.6. One of the innovative aspects is that this proposal aims to dissect the mechanisms of an unconventional function of lens connexin. Moreover, the research program will be accomplished using our established avian retroviral approaches as the principal tool for experimental manipulations of primary chick lens cultures as well as in vivo chick lenses. It is our expectation that our experimental findings will provide the molecular basis for understanding the functions and regulation of Cx45.6 in differentiating lens fibers and have a major impact on defining how gap junctions are involved in lens growth and development. The outcomes of our research will be significant because the new knowledge discovered will contribute to a broader understanding of gap junctions and connexins in cell differentiation and tissue development. Furthermore, this research activity should make a contribution to the therapeutic strategies for the treatment of eye diseases such as cataracts and provide new ideas for potential targets for drug discovery and development.