EXTRACELLULAR MATRIX ABNORMALITIES IN CORNEAL EDEMA

角膜水肿的细胞外基质异常

• 批准号: 6179950
• 负责人: MARIA C KENNEY
• 金额: $ 24.56万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-08-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6179950
• 关键词: cell adhesion; cell growth regulation; cell migration; cell proliferation; cornea edema; corneal endothelium; corneal epithelium; cytokine; extracellular matrix proteins; gene expression; growth factor; human tissue; immunocytochemistry; immunofluorescence technique; in situ hybridization; intraocular aqueous flow; nucleic acid probes; organ culture; pathologic process; polymerase chain reaction; protein structure function; tenascin; vision disorders

DESCRIPTION (Adapted from applicant's abstract): Pseudophakic (PBK) and aphakic (ABK) bullous keratopathy is the most common indication for corneal transplantation. The investigators have showed that in PBK/ABK corneas, there is an increased expression and deposition of specific isoforms of an extracellular matrix protein, tenascin-C (TN-C), that is not expressed in normal corneas. TN-C can affect cell adhesion, migration and proliferation that are important in wound healing and tissue remodeling. They have also shown that PBK/ABK corneas have a corresponding increase in the expression of TN-C integrin receptors and certain growth factors/cytokines, which could induce TN-C expression. The following hypotheses are proposed: (1) that PBK/ABK corneas present an ongoing "injury-response cycle" where the entire cornea stays in a continuous state of remodeling, (2) growth factors and/or cytokines play an important role in this cycle, and (3) the expression and deposition of TN-C affects the adhesive, migratory, proliferative and functional properties of corneal cells. Understanding these facets could lead to future therapeutic interventions. While TN-C, growth factors and cytokines are thought to play a significant role in PBK/ABK pathogenesis, other as yet unidentified abnormalities are probably also involved. Therefore, powerful new micro-sensitive techniques have been adapted for differential screening of genes from individual corneas. The hypothesis is that with these techniques, abnormalities in the expression of other genes important for PBK/ABK pathogenesis will be identified. There are three specific aims: (1) to determine the function of TN-C isoforms in PBK/ABK corneas by growing corneal cells on various isoforms of TN-C and determine rates of cell adhesion, migration, proliferation and function; (2) to determine the influence of growth factors and cytokines upon the expression of TN-C and TN-C binding integrins by: (a) identifying the abnormal growth factors/cytokines in PBK/ABK corneas, (b) determining the effects that these factors and dexamethasone have on the expression of TN-C and its binding integrins in corneal cells in vitro, and (c) determining if various isoforms of TN-C can affect the expression of TN-C binding integrins in vitro; and (3) to examine the differential gene expression in normal and PBK/ABK corneas and identify unique gene expression patterns by: (a) screening cellular mRNAs in normal vs. PBK/ABK corneas and cell layers using differential display, nucleic acid array and subtraction libraries; (b) determining if differentially-expressed genes are specific for PBK/ABK; and (c) determining whether altered gene expression in PBK/ABK is reflected at the protein level.

描述（改编自申请人摘要）：人工晶状体（PBK）和 无晶状体（ABK）大泡性角膜病变是角膜炎最常见的适应症。 移植 研究人员已经表明，在PBK/ABK角膜中， 存在增加的表达和沉积的特异性同种型， 细胞外基质蛋白，腱生蛋白-C（TN-C），不表达于 正常的角膜 TN-C可影响细胞的粘附、迁移和增殖 对伤口愈合和组织重塑很重要 他们还 显示PBK/ABK角膜具有相应的表达增加， TN-C整合素受体和某些生长因子/细胞因子， 诱导TN-C表达。 提出了以下假设：（1） PBK/ABK角膜呈现出一个持续的“损伤-反应循环”，其中整个 角膜保持持续重塑状态，（2）生长因子和/或 细胞因子在此循环中起重要作用，和（3）表达和 TN-C的沉积影响粘附性、迁移性、增殖性和 角膜细胞的功能特性。 了解这些方面可以 导致未来的治疗干预。 虽然TN-C、生长因子和细胞因子被认为在肿瘤的发生发展中起着重要作用， 在PBK/ABK发病机制中的作用，其他尚未确定的异常是 可能也参与其中。 因此，强大的新型微敏感技术 已被改造用于个体基因的差异筛选， 角膜 假设是，通过这些技术， 对PBK/ABK发病机制重要的其他基因的表达将是 鉴定 具体目标有三：（1）确定功能 通过在各种不同的培养条件下培养角膜细胞， TN-C亚型，并测定细胞粘附，迁移， 增殖和功能;（2）确定生长因子的影响 和细胞因子，通过以下方式表达TN-C和TN-C结合整联蛋白： (a)鉴定PBK/ABK角膜中的异常生长因子/细胞因子， (b)确定这些因素和地塞米松对 TN-C及其结合整合素在体外角膜细胞中的表达，和 (c)确定TN-C的各种同种型是否可以影响 TN-C结合整合素的体外实验;（3）检测差异基因 在正常和PBK/ABK角膜中的表达，并鉴定独特的基因表达 模式：（a）筛选正常与PBK/ABK角膜中的细胞mRNA， 使用差异显示、核酸阵列和减法的细胞层 库;（B）确定差异表达的基因是否具有特异性 （c）确定在PBK/ABK中改变的基因表达是否 反映在蛋白质水平上。