Molecular Regulation of Corneal Wound Healing

角膜伤口愈合的分子调控

基本信息

批准号：
7584800
负责人：
Fu-Shin X Yu
金额：
$ 38万
依托单位：
WAYNE STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-08-01 至 2013-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7584800
关键词：
1-Phosphatidylinositol 3-Kinase AKT Signaling Pathway Abbreviations Acetylcysteine Adverse effects Affect Animal Model Antioxidants Attenuated Biological Preservation Blindness Clinical Cornea Corneal Injury Defect Diabetes Mellitus Diet Disease Epidermal Growth Factor Receptor Epithelial Epithelial Cells Epithelium Extracellular Signal Regulated Kinases Family suidae Generations Glucose Goals Grant Healed Homeostasis Human Hyperglycemia Impaired wound healing Insulin-Dependent Diabetes Mellitus Keratitis Keratopathy Knowledge Laboratories Lead Ligands Light Literature Measures Mediating Mediator of activation protein Modeling Molecular Molecular and Cellular Biology Organ Culture Techniques Oxidative Stress Pathogenesis Pathway interactions Patients Play Property Proto-Oncogene Proteins c-akt Publishing Rattus Reactive Oxygen Species Receptor Activation Receptor Protein-Tyrosine Kinases Receptor Signaling Recurrence Regulation Role Serum Signal Pathway Signal Transduction Streptozocin Testing Vision Vitrectomy Wound Healing base cell injury corneal epithelium diabetic diabetic patient diabetic rat effective therapy extracellular healing heparin-binding EGF-like growth factor microbial normal aging novel oxidative damage patient population public health relevance receptor downregulation response restoration therapeutic development therapy development wound

项目摘要

DESCRIPTION (provided by applicant): The long-term goal of the laboratory has been to obtain basic information about the molecular and cellular biology of corneal wound healing. The studies in the current grant period demonstrated that epidermal growth factor receptor (EGFR) is the key receptor tyrosine kinase activated upon wounding, and the wound-induced activation of EGFR and its downstream signaling pathways, particularly ERK and PI3K, play a central role in mediating corneal epithelial wound healing. While in normal cornea an epithelial wound is usually healed in a timely fashion without any complications, epithelial wound healing is considerably delayed in the corneas of diabetic patients. The delayed healing of the epithelial defect (termed diabetic keratopathy) may result in sight threatening complications, such as persistent epithelial defect, recurrent erosion, and microbial keratitis. Preliminary studies using streptozotocin (SZT)-treated rats as a type 1 diabetes model and human diseased corneas revealed that EGFR signaling, in particular PI3K pathways, is compromised in the epithelia of diabetic rat corneas and of human diabetic, but not in normal and diet-controlled corneas. Our published and preliminary studies lead to the hypothesis that the tightly regulated EGFR signaling is abrogated by hyperglycemia in the epithelium and that strengthening of the weakened EGFR signaling, along with reducing oxidative stress, may preserve epithelial integrity and promote epithelial wound healing in the diabetic corneas. Three specific aims are proposed to test this hypothesis. 1) To characterize EGFR signaling pathways and oxidative damage in SZT diabetic rat corneas. Alterations of EGFR signaling in the epithelia of SZT-induced and human diabetic corneas will be characterized and correlated to the epithelial abnormalities observed in these diseased corneas. 2) To determine how hyperglycemia affects EGFR signaling and epithelial integrity and function in the cornea. Cultured porcine corneas and primary human corneal epithelial cells will be used. The effects of high glucose that mimics hyperglycemia on the generation of reactive oxygen species, on EGFR signaling, and on epithelial integrity and function including barrier properties and wound healing will be assessed. 3) To determine how manipulation of EGFR-signaling pathways might be used to accelerate epithelial wound healing in diabetic corneas. EGFR ligands will be combined with antioxidant and their synergistic effects on promoting epithelial wound healing and barrier function will be elucidated. The results of these proposed studies should shed light on the mechanisms underlying pathogenesis of diabetic keratopathy and lead to the identification of effective treatments for the delayed diabetic corneal epithelial wound healing which currently are lacking. PUBLIC HEALTH RELEVANCE This study will use animal models of diabetes, a unique ex vivo corneal organ culture model, cultured human corneal epithelial cells, and human diabetic corneas to study the mechanisms underlying pathogenesis of diabetic keratopathy, a disease with severe abnormalities in two thirds of patients. In the light of an ever-increasing patient population with diabetes and the lack of effective treatments for the disease, this study is of paramount importance and may lead to the development of therapeutics for treating the disease and for promoting delayed epithelial wound healing often associated with diabetic vitrectomy.

描述（由申请人提供）：实验室的长期目标是获得有关角膜伤口愈合的分子和细胞生物学的基本信息。本次资助期间的研究表明，表皮生长因子受体（EGFR）是创伤时激活的关键受体酪氨酸激酶，创伤诱导的EGFR及其下游信号通路（特别是ERK和PI3K）的激活在损伤中发挥着核心作用。介导角膜上皮伤口愈合。在正常角膜中，上皮伤口通常会及时愈合，不会出现任何并发症，而在糖尿病患者的角膜中，上皮伤口愈合则显着延迟。上皮缺损（称为糖尿病性角膜病）的延迟愈合可能会导致威胁视力的并发症，例如持续性上皮缺损、复发性糜烂和微生物性角膜炎。使用链脲佐菌素 (SZT) 治疗的大鼠作为 1 型糖尿病模型和人类患病角膜的初步研究表明，EGFR 信号传导，特别是 PI3K 通路，在糖尿病大鼠角膜和人类糖尿病患者的上皮细胞中受到损害，但在正常和饮食中则没有受到损害。 - 控制角膜。我们已发表的初步研究得出这样的假设：上皮中的高血糖会消除严格调节的 EGFR 信号传导，并且加强减弱的 EGFR 信号传导以及减少氧化应激，可能会保持上皮完整性并促进糖尿病角膜的上皮伤口愈合。提出了三个具体目标来检验这一假设。 1) 表征 SZT 糖尿病大鼠角膜的 EGFR 信号通路和氧化损伤。 SZT 诱导的和人类糖尿病角膜上皮中 EGFR 信号传导的改变将被表征，并与在这些患病角膜中观察到的上皮异常相关。 2) 确定高血糖如何影响 EGFR 信号传导以及角膜上皮完整性和功能。将使用培养的猪角膜和原代人角膜上皮细胞。将评估模拟高血糖的高血糖对活性氧生成、EGFR 信号传导以及上皮完整性和功能（包括屏障特性和伤口愈合）的影响。 3) 确定如何操纵 EGFR 信号通路来加速糖尿病角膜上皮伤口的愈合。 EGFR配体将与抗氧化剂结合，并阐明它们对促进上皮伤口愈合和屏障功能的协同作用。这些拟议研究的结果应有助于阐明糖尿病性角膜病变的发病机制，并确定目前缺乏的糖尿病角膜上皮伤口愈合延迟的有效治疗方法。公共健康相关性本研究将使用糖尿病动物模型、独特的离体角膜器官培养模型、培养的人角膜上皮细胞和人糖尿病角膜来研究糖尿病性角膜病的发病机制，糖尿病性角膜病是一种在三分之二的人中出现严重异常的疾病。患者。鉴于糖尿病患者人数不断增加，并且缺乏有效的治疗方法，这项研究至关重要，可能会导致治疗该疾病和促进通常与糖尿病有关的上皮伤口愈合延迟的疗法的开发。糖尿病玻璃体切除术。