BIOLOGY OF THE EMBRYONIC CORNEAL EPITHELIUM

这项补助金的长期目标是确定功能和 基底膜、角膜上皮、角膜基质和角膜基质之间的结构关系 细胞骨架和细胞器分布（RER，高尔基体）。已经 建立了培养的细胞形成局灶性粘连， 细胞外基质蛋白，含有细胞粘附分子，肌动蛋白 相关蛋白、激酶和钙结合蛋白。此外，本发明还提供了一种方法， 细胞粘附分子作为信号受体通过引起酪氨酸 磷酸化，Ca2+内流，细胞质pH值增加， 磷脂周转率我们将扩展以前的工作，以确定是否 这些蛋白质和机制也是重组肌动蛋白所必需的， 胚胎角膜上皮模型。事件发生的顺序 在肌动蛋白皮质垫重组过程中， 基质分子将被解剖，以确定 ECM、细胞粘附分子、细胞骨架和细胞器分布。 具体研究以下几个方面和问题。细胞-细胞和 角膜上皮发育过程中的细胞-基质相互作用。我们将 检验肌动蛋白皮质的重组取决于 在包括受体结合、肌动蛋白相关的 蛋白质重排和信号转导。有哪些具体 细胞间连接或细胞外基质之间的连接蛋白 受体和肌动蛋白？非肌动蛋白细胞骨架是如何组织的 胚胎角膜上皮细胞是重组行动 皮质垫依赖于信号转导？二.控制因素 角膜分化过程中mRNA的分布。我们已经证明了beta- 肌动蛋白mRNA在角膜上皮中具有类似于F- 肌动蛋白特定的胶原蛋白mRNA似乎也具有明显的 分布于软骨细胞和角膜上皮。我们将测试 肌动蛋白和胶原mRNA在角膜中组织化的假设 上皮细胞通过细胞骨架依赖机制和重组 是上调基质合成的一个因素。如何 细胞组织肌动蛋白和胶原mRNA吗？将中断的 细胞骨架也破坏胶原mRNA的分布？三.因素 在肌动蛋白皮质垫期间控制细胞器分布 重组。我们以前已经证明， 细胞松弛素D引起基底室粗面内质网减少， 上皮细胞与基底层分离。我们将检验这个假设， 细胞骨架元件组织蛋白质分泌细胞器， 翻译辅因子来调节分泌蛋白的表达。是 翻译辅因子或通过附着稳定的内质网 到细胞骨架上是什么机制导致了这种依恋？ 总之，角膜上皮相互作用的细胞生物学模型 细胞外环境和细胞组织之间的联系 开发

The long-term objective of this grant is to determine the functional and structural relationships between the basement membrane, corneal epithelial cytoskeleton and organelle distribution (RER, Golgi). It has been established that cultured cells form focal adhesions in response to extracellar matrix proteins that contain cell adhesion molecules, actin associated proteins, kinases and calcium binding proteins. In addition, cell adhesion molecules act as signaling receptors by causing tyrosine phosphorylation, Ca2+ influx, an increase in cytoplasmic pH and phospholipid turnover. We will expand this previous work to determine if these proteins and mechanisms are also necessary for reorganizing actin in the embryonic corneal epithelial model. The sequence of events that occur during actin cortical mat reorganization in response to extracellular matrix molecules will be dissected to determine the relationships between the ECM, cell adhesion molecules, cytoskeleton and organelle distribution. We will study the following specific areas and questions: I. Cell-cell and cell-matrix interactions during corneal epithelial development. We will test the hypothesis that the reorganization of the actin cortical depends upon a cascade of events including receptor binding, actin associated protein rearrangements, and signal transduction. What are the specific link proteins between cell-cell junctions or extracellular matrix receptors and actin? How is the non-actin cytoskeleton organized in embryonic corneal epithelial cells? Is the reorganization of the actin cortical mat dependent on signal transduction? II. Factors controlling mRNA distribution during corneal differentiation. We have shown that beta- actin mRNA has a polarized distribution in corneal epithelia similar to F- actin protein. Specific collagen mRNAs also appear to have a distinct distribution in chondrocytes and corneal epithelia. We will test the hypothesis that actin and collagen mRNA are organized in the corneal epithelium by a cytoskeletal dependent mechanism and that reorganization of the cytoskeleton is a factor in up-regulating matrix synthesis. How does the cell organize actin and collagen mRNA? Will disruption of the cytoskeleton also disrupt collagen mRNA distribution? III. Factors controlling organelle distribution during actin cortical mat reorganization. We have previously shown that disrupting actin with cytochalasin D caused the RER in the basal compartment to decrease in epithelia isolated with the basal lamina. We will test the hypothesis that cytoskeletal elements organize protein secretion organelles and translation cofactors to regulate expression of secreted proteins. Are translational cofactors or endoplasmic reticulum stabilized by attachment to the cytoskeleton? What mechanisms are responsible for this attachment? In summary, a cell biological model for corneal epithelial interactions between the extracellular environment and cellular organization has been developed.