Mechanisms of Lens Morphogenesis and Regeneration

项目摘要 为了在损伤后再生功能性组织或替换被损伤破坏的组织， 病理性疾病的后果，干细胞或祖细胞的分化必须伴随着 通过有效的策略来促进组织形态发生。该提案探讨了 指导细胞和组织形态发生，最终目标是应用结果指导重演 组织修复和再生的正常发育过程。这些研究的模型是 胚胎透镜是研究形态发生的分子机制的理想材料，因为它 细胞结构决定其功能。必须精确地执行透镜的形态形成， 保持，以便使其执行其在视网膜上聚焦图像的功能。这项建议旨在 发现负责透镜发育的两个主要形态发生事件的机制：1） 建立高度伸长的透镜纤维细胞表型的伸长/会聚延伸机制 以及2）相邻的透镜纤维单元被组织成精确的六边形堆积的机制 蜂窝阵列研究主要集中在N-钙粘蛋白连接及其与不同细胞的动态相互作用， 细胞骨架元件作为发育过程中细胞和组织形态发生的关键调节剂。为这些 我们开发了许多重要的培养模型，包括：1）离体模拟白内障手术 培养物，其中可以检查透镜上皮对临床相关创伤的反应， 其天然微环境及其再生晶状体样组织的能力，2）透镜上皮的原代培养物 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 伸长并组织成高度有序的组织样结构;除了N-钙粘蛋白纤维细胞特异性 击倒对手。这些模型提供了强大的工具，可以检查N-钙粘蛋白作为一个焦点， 肌动蛋白微丝、微管和中间丝协调它们的功能以引导透镜 形态发生与以下问题：驱动纤维细胞伸长的机制是什么？怎么 相邻的透镜纤维细胞相互作用以形成功能结构？是什么调节纤维细胞的组织 变成六边形阵列是什么稳定了透镜这种独特的细胞结构？透镜上皮细胞是如何 重塑它们的N-钙粘蛋白/细胞骨架相互作用以促进伤口愈合和组织再生？的结果 这些拟议的研究预计将确定负责建立和 维持细胞和组织的细胞结构，这方面的知识将为指导 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.