GENESIS OF CELL MEMBRANE POLARITY IN CORNEAL EPITHELIUM

角膜上皮是一种极化的多层组织， 具有高效、多项生理和防护作用 在进行快速细胞置换时，对角膜健康至关重要。至 提高对参与运动的生理活动的了解 为了保存正常的上皮，这项为期5年的研究检查了一些 A)表面细胞更替的基础事件 和b)细胞膜极性的成熟。 在它们通过上皮层迁移的过程中。对这些人来说至关重要 研究的最新进展是一种诱导皮肤脱落的方法 一层一层地培养上皮细胞。该方法允许解剖 上皮分成5个可区分的层，从而便于 研究随着细胞的进展而发生的一些性质或功能的变化 沿着底部到地表的层结轴线。 紧密连接(T.J.)成熟的表面细胞之间 将通过电子显微镜来确定。然后，在诱导剥落之后 在这些细胞中，T.J.新版本之间的组装 表面的细胞将被表征。黄曲霉毒素的蛋白质组成 S和特异蛋白的胞内动员细节 T.J.组装的研究将使用a)一种针对 一个必不可少的T.J.卵红蛋白成分，以及b)新生组织的放射性标记 蛋白质合成(翻译)过程中的蛋白质紧致依赖阶段 结合部形成。对T.J.来说至关重要的平移步骤的位置。 大会已经建立，研究以确定 进行转录(信使核糖核酸合成)步骤。电生理学 将使用方法来确定分层过程中的哪个点 CL-通道插入根尖膜内。扫描电子 显微镜和一组荧光凝集素将被用于研究 牙根尖膜的成熟显微解剖及表面表达 加糖。将评估伴随而来的基侧活动变化。 通过测定β-肾上腺素能受体Na++K+ATPase的变化。 不利环境条件对表面细胞的影响 还将检查更换过程以及某些 细胞膜极性成熟的生物学变量 文化体系。

The corneal epithelium is a polarized, multilayered tissue that fulfills, with high efficiency, a number of physiological and protective roles essential to corneal health while undergoing rapid cell replacement. To improve understanding of the physiological activities involved in the preservation of a normal epithelium, this 5-year study examines some of the fundamental events that underlie a) the replacement of cells at the surface of the cornea, and b) the maturation of membrane polarity of the cells during their migration through the epithelial strata. Essential to these studies is the recent development of a method to induce exfoliation of the epithelial cells on a layer-by-layer fashion. The method allows dissection of the epithelium into 5 distinguishable layers thereby facilitating the study of changes in a number of properties or functions as cells progress along the basal-to-surface stratification axis. The ultrastructure of tight junctions (t.j.) between mature surface cell will be determined by electron microscopy. Then, after induced exfoliation of these cells, the structural dynamics of t.j. assembly between the new cells at the surface will be characterized. The protein composition of t.j.'s and details of the intracellular mobilization of specific proteins t.j. assembly will be studied using a) a monoclonal antibody raised against an essential t.j. component, ovomorulin, and b) radiolabelling of nascent proteins during a protein synthesis (translation) dependent-phase of tight junction formation. The location of a translational step critical for t.j. assembly had already been established, studies to determine a transcriptional (mRNA synthesis) step are undertaken. Electrophysiological methods will be used to determine at which point during stratification Cl-channels are inserted in the apical membrane. Scanning electron microscopy and a battery of fluorescent lectins will be used to study the maturation of the apical membrane microanatomy and surface expression of sugars. The concomitant changes in basolateral activities will be assessed by measuring the changes in Na++K+ ATPase in beta-adrenergic receptors. The effect of unfavorable environmental conditions on the surface cell replacement process will also be examined as well as the effect of certain biological variables on the maturation of membrane polarity in a cell culture system.