REGENERATION OF CORNEAL EPITHELIUM AND ENDOTHELIUM

EGF对角膜内皮细胞增殖的调控作用， 分析了 EGF结合，内化和降解的相关性 将定义细胞分裂的诱导。 我们还将研究 EGF与细胞核受体位点和细胞表面受体位点的结合。 EGF对细胞质蛋白质合成的影响，这可能是 参与支持细胞通过G1期的进展， 细胞周期，将作为细胞周期和细胞密度的函数进行研究。 在融合时，细胞表面受体的限制 侧向移动可以阻止EGF受体复合物的内化， 将研究它们随后对细胞分裂的触发。 的作用 细胞外基质（ECM）在角膜内皮细胞调控中的作用 将使用两种细胞株分析增殖和分化， 角膜内皮细胞 一种在体外表达其正常表型， 在存在FGF的情况下维持，而另一种在不存在FGF的情况下维持， 成纤维细胞生长因子，不再表达它。 分泌的胶原蛋白类型产生的稀疏与汇合培养物 在存在或不存在FGF或EGF的情况下维持的角膜内皮细胞 将使用间接免疫荧光技术进行分析。 这将是 随后进行了组成和生产的生化分析， 角膜内皮细胞稀疏培养物与融合培养物产生的胶原蛋白 在EGF或FGF存在或不存在下维持的细胞。 直接 FGF和EGF对胶原蛋白合成的调节作用， 将分析在汇合时表达正常表型的细胞。 的 ECM对细胞增殖的允许作用的性质， 分化将通过研究增殖和 在涂有牛角膜产生的ECM的培养皿上进行分化 不增殖的眼系统细胞类型的内皮细胞 （人角膜内皮细胞）或分化（角膜上皮细胞） 塑料

The control of proliferation of corneal endothelial cells by EGF will be analyzed. The relevance of EGF binding, internalization, and degradation for the induction of cell division will be defined. We will also study the possible binding of EGF to nuclear receptor sites versus cell surface receptor sites. The effect of EGF on the synthesis of cytoplasmic proteins, which may be involved in supporting the progression of the cells through the G1 phase of the cell cycle, will be studied as a function of the cell cycle and of cell density. The possibility that, at confluence, a restriction in the cell surface receptor lateral mobility could prevent the internalization of EGF receptor complexes and their subsequent triggering of cell division will be investigated. The role of the extracellular matrix (ECM) in events controlling corneal endothelial cell proliferation and differentiation will be analyzed using two cell strains of corneal endothelial cells. One expresses its normal phenotype in vitro when maintained in the presence of FGF, while the other, maintained in the absence of FGF, no longer expresses it. The composition, distribution, and polarity of secretion of collagen types produced by sparse versus confluent cultures of corneal endothelial cells maintained in the presence or absence of FGF or EGF will be analyzed using indirect immunofluorescence techniques. This will be followed by the biochemical analysis of the composition and production of collagen produced by sparse versus confluent cultures of corneal endothelial cells maintained in the presence or absence of EGF or FGF. The direct modulation of collagen synthesis by FGF and EGF when added to cultures which no longer express their normal phenotype at confluence will be analyzed. The nature of the permissive effect of the ECM on cell proliferation and differentiation will be studied by investigating the proliferation and differentiation on dishes coated with an ECM produced by bovine corneal endothelial cells of cell types of the ocular system which do not proliferate (human corneal endothelial cells) or differentiate (corneal epithelial cells) on plastic.