EXTRACELLULAR MATRIX ABNORMALITIES IN CORNEAL EDEMA

角膜水肿的细胞外基质异常

• 批准号: 6459478
• 负责人: MARIA C KENNEY
• 金额: $ 18.35万
• 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 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6459478
• 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（改编自申请人的摘要）：人工晶体眼（PBK）和 无晶状体眼（ABK）大疱性角膜病是角膜最常见的适应症 移植。 研究人员表明，在 PBK/ABK 角膜中， 特定亚型的表达和沉积增加 细胞外基质蛋白，腱蛋白-C (TN-C)，不表达于 正常角膜。 TN-C可影响细胞粘附、迁移和增殖 这对于伤口愈合和组织重塑很重要。 他们还有 表明PBK/ABK角膜的表达量相应增加 TN-C 整合素受体和某些生长因子/细胞因子，这可以 诱导 TN-C 表达。 提出以下假设： (1) PBK/ABK 角膜呈现出一个持续的“损伤反应周期”，其中整个角膜 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发挥重要作用，并且（3）表达和 TN-C的沉积影响粘附、迁移、增殖和 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发挥着重要作用 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 已适应个体基因的差异筛选 角膜。 假设通过这些技术，异常 对 PBK/ABK 发病机制重要的其他基因的表达将是 确定。 具体目的有3个：（1）确定函数 通过在各种条件下培养角膜细胞，在 PBK/ABK 角膜中制备 TN-C 亚型 TN-C 亚型并确定细胞粘附、迁移、 增殖和功能； (2)确定生长因子的影响 和细胞因子对 TN-C 和 TN-C 结合整联蛋白表达的影响： (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 体外角膜细胞中TN-C及其结合整合素的表达，以及 (c)确定TN-C的各种亚型是否可以影响 TN-C 体外结合整合素； (3)检查差异基因 正常角膜和 PBK/ABK 角膜中的表达并识别独特的基因表达 模式通过：(a) 筛选正常角膜与 PBK/ABK 角膜中的细胞 mRNA，以及 使用差异显示、核酸阵列和减法的细胞层 图书馆； (b) 确定差异表达基因是否具有特异性 对于 PBK/ABK； (c) 确定 PBK/ABK 中的基因表达是否发生改变 体现在蛋白质水平上。