Mechanisms of Lens Morphogenesis and Regeneration

项目摘要 为了在受伤后再生有功能的组织或替换被 一种病理疾病的后果，干细胞或祖细胞的分化必须伴随 通过有效的策略促进组织形态发生。这项提案调查了 指导细胞和组织形态发生，最终目的是应用结果来指导重述 在组织修复和再生方面的正常发育过程。这些研究的模型是 胚胎晶状体，是研究形态发生的分子机制的理想选择，因为它 细胞结构决定了它的功能。晶状体的形态发生必须精确执行，其结构 为了使其能够将图像聚焦在视网膜上而进行维护。这项建议旨在 发现晶状体发育的两个主要形态发生事件的机制：1) 建立高度伸长晶状体纤维细胞表型的伸长/收敛伸展机制 2)相邻的晶状体纤维细胞被组织成精确的六角形堆积的机制 蜂窝阵列。重点研究了N-钙粘素连接及其与不同细胞因子的动态相互作用。 细胞骨架元素是发育过程中细胞和组织形态发生的关键调节器。为了这些 研究中我们建立了许多重要的培养模型，包括：1)体外模拟白内障手术 可以检测晶状体上皮对临床相关损伤的反应的培养。 其自然微环境及其再生晶状体样组织的能力；2)晶状体上皮细胞的原代培养 在培养中分化形成微型晶状体结构的细胞，以及3)上皮外植体，其中纤维细胞 拉长并组织成高度有序的组织状结构；除了N-钙粘蛋白纤维细胞特有的 淘汰赛。这些模型提供了强大的工具，可用于检查N-钙粘素作为焦点 肌动蛋白微丝、微管和中间丝协调其定向晶状体的功能 形态发生与以下问题：驱动纤维细胞伸长的机制是什么？做什么 相邻的晶状体纤维细胞相互作用形成功能结构？是什么调节了纤维细胞的组织 变成一个六角形的阵列？是什么稳定了晶状体的这种独特的细胞结构？晶状体上皮细胞如何 重塑N-钙粘素/细胞骨架的相互作用，以促进伤口愈合和组织再生？结果是 这些拟议的研究预计将确定负责建立和实施 维持细胞和组织的细胞结构，了解这些结构将为指导提供实质性的目标 体内有效的组织再生。

Project Summary In order to regenerate a functional tissue following an injury or to replace a tissue destroyed by the consequences of a pathological disease, the differentiation of stem or progenitor cells must be accompanied by effective strategies to promote tissue morphogenesis. This proposal investigates the mechanisms that guide cell and tissue morphogenesis with the ultimate goal of applying the results to instruct the recapitulation of normal developmental processes in tissue repair and regeneration. The model for these studies is the embryonic lens, ideal for investigating the molecular mechanisms of morphogenesis because its cytoarchitecture defines its function. Morphogenesis of the lens must be precisely executed and its structure maintained in order for it to perform its function of focusing images on the retina. This proposal aims to discover the mechanisms responsible for the two principal morphogenetic events of lens development: 1) the elongation/convergent extension mechanism that establishes the highly elongated lens fiber cell phenotype and 2) the mechanism by which neighboring lens fiber cells are organized into an exact hexagonally packed cellular array. The studies are focused on N-cadherin junctions and their dynamic interactions with different cytoskeletal elements as key modulators of cell and tissue morphogenesis during development. For these studies we developed a number of important culture models including: 1) ex vivo mock cataract surgery cultures where it is possible to examine the response of the lens epithelium to a clinically relevant wounding in its native microenvironment and its ability to regenerate lens-like tissue, 2) primary cultures of lens epithelial cells that differentiate in culture to form mini-lens structures, and 3) epithelial explants where fiber cells both elongate and organize into a highly ordered tissue-like structure; in addition to N-cadherin fiber cell-specific knockouts. These models provide powerful tools with which to examine N-cadherin as a focal point where actin microfilaments, microtubules and intermediate filaments coordinate their function to direct lens morphogenesis with the following questions: What are the mechanisms that drive fiber cell elongation? How do neighboring lens fiber cells interact to form a functional structure? What regulates the organization of fiber cells into a hexagonal array? What stabilizes this unique cytoarchitecture of the lens? How do lens epithelial cells remodel their N-cadherin/cytoskeletal interactions for wound healing and tissue regeneration? The results of these proposed studies are expected to identify the underlying mechanisms responsible for establishing and maintaining cell and tissue cytoarchitecture, knowledge of which would provide substantive targets for guiding effective tissue regeneration in vivo.