Intercellular Communication in the Eye Lens

描述（由申请人提供）：已知连接蛋白形成的间隙连接对于维持眼透镜的代谢稳态至关重要。我们以及其他人最近发现了透镜连接蛋白的一个新特征，发现其在功能上参与促进上皮纤维分化和透镜发育。我们的长期目标是了解缝隙连接及其组成部分连接蛋白在透镜发育和稳态中的调节机制和功能意义。本申请的目的是了解Cx45.6在细胞分化和透镜生长和发育中的机制作用。中心假设是，Cx45.6，不像其他两种类型的透镜连接蛋白，是在功能上参与的分化过程和成熟的透镜纤维的形成。这一假说是基于我们的初步研究结果而提出的，初步研究结果表明，Cx45.6的表达增强了透镜上皮纤维的分化，而Cx45.6受caspase-3的后调节，caspase-3积极参与了终末透镜的分化。具体目标有三个：（1）。确定Cx45.6表达在上皮纤维分化和透镜发育中的功能参与; 2）.鉴定对透镜分化的刺激作用重要的Cx45.6分子的功能结构域，并表征Cx45.6和MIP以及其他潜在因子之间的相互作用，和3）。确定胱天蛋白酶-3介导的Cx45.6切割的功能意义。本研究的创新点之一是旨在剖析透镜连接蛋白的非传统功能机制。此外，该研究计划将使用我们建立的禽逆转录病毒方法作为主要工具，用于实验操作的主要鸡透镜培养物以及体内鸡透镜。我们期望我们的实验结果将为理解Cx45.6在分化透镜纤维中的功能和调节提供分子基础，并对确定间隙连接如何参与透镜生长和发育产生重大影响。我们的研究成果将是重要的，因为发现的新知识将有助于更广泛地了解细胞分化和组织发育中的间隙连接和连接蛋白。此外，这项研究活动应有助于治疗白内障等眼病的治疗策略，并为药物发现和开发的潜在靶点提供新思路。

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.