MOLECULAR ASPECTS OF CORNEAL EPITHELIAL MIGRATION

角膜上皮迁移的分子方面

• 批准号: 6384621
• 负责人: Mary Ann Stepp
• 金额: $ 26.8万
• 依托单位: GEORGE WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-07-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6384621
• 关键词: RNase protection assay; basement membrane; cell adhesion; cell cell interaction; cell migration; confocal scanning microscopy; corneal epithelium; electron microscopy; extracellular matrix; gene expression; gene targeting; genetically modified animals; growth factor; in situ hybridization; integrins; intercellular connection; laboratory mouse; messenger RNA; molecular biology; neurotrophic factors; northern blottings; organ culture; phosphorylation; polymerase chain reaction; protein biosynthesis; wound healing

DESCRIPTION: Epithelial migration and/or adhesion to the basement membrane are compromised in recurrent epithelial erosions and persistent epithelial defects. To better understand how epithelial cells migrate in response to injury in the cornea, it is important to understand the adhesive interactions that exist between the epithelium and the underlying basement membrane. Previously, it was hypothesized that integrins, a family of cell surface receptors which are known to be involved in mediating cell:substrate interactions and signal transduction in many cell types, were involved in cell migration in the corneal epithelium. It was shown that distinct integrins, including a6B4 and a9, are expressed at elevated levels during healing in response to debridement and that their expression appears correlated with cell proliferation. Also shown previously was that a6B4 integrin was a component of the hemidesmosomes, those stable attachment sites which allow the epithelium to remain adherent when not migrating. Aim 1 of this proposal is to determine whether the accumulation a6B4 protein in corneal epithelial cells in vivo in response to injury is regulated by changes in mRNA expression, protein turnover rates, or by phosphorylation. Aim 2 is to determine whether increased expression of a6B4 during migration in vivo alters the properties of the cells as compared to cells migrating in vitro by measuring cell adhesion, cell:cytoskeletal associations, cell proliferation, and cell signaling in both models. Aim 3 is to determine the role environmental factors, including growth factors (EGF, HGF, IGF, TGFB) and neurotrophic factors, play in the quality of the wound response using rat corneal debridement wounds B in vitro and in organ culture. Aim 4 is to determine whether initiation of cell proliferation using the excimer laser to ablate superficial cell layers only induces integrin expression in the corneal epithelium. Aim 5 is hemidesmomes after wounding using morphometry and tenascin knockout mice. The proposed studies of integrin expression in the corneal epithelium will provide insight into the basic cell biology of migration and the role of integrin:matrix interactions in the healing of corneal wounds.

描述：上皮迁移和/或粘附到基底膜 复发性上皮糜烂和持续性上皮糜烂受到损害 缺陷。 为了更好地了解上皮细胞如何响应迁移 角膜受伤，了解粘合剂很重要 上皮和底层基底之间存在的相互作用 膜。 此前，人们假设整合素（一个细胞家族） 已知参与介导细胞：底物的表面受体 许多细胞类型中的相互作用和信号转导，参与 角膜上皮细胞的迁移。 结果表明，明显 整合素，包括 a6B4 和 a9，在 清创后愈合，并且它们的表达出现 与细胞增殖有关。 之前还显示了 a6B4 整合素是半桥粒的一个组成部分，那些稳定的附着 使上皮在不迁移时保持粘附的位点。 目的 该提案的1是确定a6B4蛋白是否在 体内角膜上皮细胞对损伤的反应受以下因素调节 mRNA 表达、蛋白质周转率或磷酸化的变化。 目标 2 是确定迁移过程中 a6B4 的表达是否增加 与在体内迁移的细胞相比，体内改变了细胞的特性 体外通过测量细胞粘附、细胞：细胞骨架关联、细胞 两种模型中的增殖和细胞信号传导。 目标 3 是确定 环境因素的作用，包括生长因子（EGF、HGF、IGF、TGFB） 和神经营养因子，在伤口反应的质量中发挥作用 大鼠角膜清创伤口 B 体外和器官培养。 目标 4 是 使用准分子激光确定细胞增殖是否开始 消融表面细胞层仅诱导整合素表达 角膜上皮。 目标 5 使用形态测定法测量受伤后的半桥粒 和生腱蛋白敲除小鼠。 整合素表达的拟议研究 角膜上皮将提供对基本细胞生物学的深入了解 迁移和整合素的作用：基质相互作用在愈合中 角膜伤口。