Corneal Epithelial Cell Surface Glycoconjugates

描述（由申请方提供）：上皮无法在伤口上迁移或迁移的上皮无法保持与基质的粘附，可能导致角膜出现许多使人衰弱的临床状况，包括复发性糜烂和持续性上皮缺损。我们在之前的资助期间确定了两种碳水化合物结合蛋白，半乳糖凝集素-3和-7，是介导角膜上皮细胞迁移的关键分子之一。为了理解半乳糖凝集素-3和-7介导角膜上皮细胞迁移的机制，在目的1中，我们将鉴定和表征作为半乳糖凝集素-3和-7的反受体的角膜上皮细胞表面和细胞外基质（ECM）糖蛋白，并将确定凝集素是否通过结合众所周知的整联蛋白、生长因子受体、和/或ECM分子。在目标2中，使用小干扰RNA（siRNA）和/或反义腺病毒构建体、cDNA微阵列和糖基因阵列，我们将确定半乳糖凝集素-3是否通过调节关键粘附和/或信号转导分子的表达间接介导角膜上皮细胞迁移。在目的3中，通过确定半乳糖凝集素-3和/或-7是否调节特异性激酶（粘着斑激酶、蛋白激酶B、MAP激酶）的活化，我们将确定凝集素是否通过调节特异性信号转导途径介导角膜上皮细胞迁移。 拟议的研究将有助于更好地了解角膜上皮细胞迁移的分子基础，并最终帮助找到治疗不愈合角膜伤口的新治疗策略。此外，这项研究将有助于对受损或延迟上皮再生的一般疾病的基本了解，包括老年人的慢性伤口、褥疮性溃疡和皮肤静脉郁积性溃疡，这些疾病共同影响着全球数百万人。

DESCRIPTION (provided by applicant): The failure of the epithelium to migrate over the wound or of the migrated epithelium to remain adherent to the substratum may lead to the development of a number of debilitating clinical conditions of the cornea including recurrent erosions and persistent epithelial defects. We established during the previous funding period that two carbohydrate binding proteins, galectins-3 and -7, are among the key molecules which mediate corneal epithelial cell migration. For an understanding of the mechanism by which galectins-3 and -7 mediate corneal epithelial cell migration, in Aim 1, we shall identify and characterize the corneal epithelial cell surface and extracellular matrix (ECM) glycoproteins which serve as counterreceptors of galectins-3 and -7, and will establish whether the lectins modulate corneal epithelial cell migration by binding to well-known integrins, growth factor receptors, and/or ECM molecules. In Aim 2, using small interfering RNA (siRNA) and/or antisense adenoviral constructs, cDNA microarrays and glycogene arrays, we shall determine whether galectin-3 mediates corneal epithelial cell migration indirectly by modulating the expression of key adhesion and/or signal transduction molecules. In Aim 3, by determining whether galectins-3 and/or -7 modulate the activation of specific kinases (focal adhesion kinase, protein kinase B, MAP kinases) that are well known for their role in cell migration, we shall establish whether the lectins mediate corneal epithelial cell migration by modulating specific signal transduction pathways. The proposed studies will contribute to a better understanding of the molecular basis of corneal epithelial cell migration and should ultimately help find novel therapeutic strategies for treating nonhealing corneal wounds. In addition, this study will contribute to the basic understanding of the general disorders of impaired or delayed re-epithelialization including chronic wounds in the elderly, decubitus ulcers, and venous stasis ulcer of the skin, conditions that together affect millions of individuals worldwide.