ESOPHAGEAL CYTOPROTECTION--AGENTS AND MECHANISMS

食管细胞保护——代理和机制

基本信息

批准号：
7918703
负责人：
Roy Charles Orlando
金额：
$ 9.79万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-23 至 2010-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7918703
关键词：
Acidity Acids Aftercare Age Animal Model Apical Buffers Caucasians Caucasoid Race Cell membrane Cell surface Cells Clinical Confocal Microscopy Coupled Cyclic AMP Cytoprotection Cytoskeleton Data Defect Desmosomes Disease Elderly Electrical Resistance Endoscopic Biopsy Epithelial Epithelium Esophageal Esophageal Tissue Esophagitis Esophagus Event Exposure to Freeze Fracturing Frequencies Functional disorder Genetic Goals Grant Heartburn Histologic Human In Vitro Inflammation Inflammatory Intercellular Junctions Ions Knowledge Measurement Medical Microelectrodes Modeling Monitor Morphology Operative Surgical Procedures Oryctolagus cuniculus Pathogenesis Pathway interactions Patients Peptic Esophagitis Perfusion Permeability Physiological Property Protein Biosynthesis Proteins Reaction Reflux Relapse Resistance Role Second Messenger Systems Severities Shunt Device Site Sodium Chloride Sodium Dodecyl Sulfate-PAGE Stomach Structure Symptoms Technology Testing Tight Junctions Time Tissues Zonula Adherens density design falls high risk human disease immunocytochemistry in vivo insight male research study second messenger

项目摘要

The long term goal of this proposal is to understand the pathogenesis of the human disease, reflux esophagitis (RE), and this approached mechanistically and from the relatively uncommon vantage point of the target tissue, the esophageal epithelium (EE). In this grant, we focus on the barrier properties of the EE, and especially that of the intercellular junctions (ICJs). The ICJs have importance as an essential defense against H+ entry into EE and as the initial target for H+ attack and damage that culminates in esophagitis. Therefore, one major goal is to characterize the barrier properties to select ions and molecules of the lumen-facing, apical cell membranes (ACMs) and ICJs using in vitro rabbit EE in Ussing chambers, and to determine how exposure to luminal acid alters these properties. Also, since many patients with RE have normal acid contact time on pH monitoring, experiments in Ussing chambered-EE are designed to identify (non-acidic) factors within the refluxate, meals and the esophageal inflammatory reaction that can contibute to breaking the barriers to H+ entry into EE, and for those identified, to localize the site of action to ACMs and/or ICJs and characterize, by pH-microelectrodes, the ability to lower pHi. Further, there is evidence to suggest that patients with RE have defects in (epithelial) barrier function, and that those with nonerosive esophagitis have damage localized to the ICJs. Since localization to the ICJs is key to validating our proposed pathogenesis of heartburn and esophagitis, another goal is to confirm, using in vivo PD measurements during salt superfusions, that this defect is localized to the ICJs. Moreover, there is a high rate of relapse following medical therapy and preliminary data suggest that this is attributable to persistent defects within the EE. Therefore, we hypothesize that the defects are due to persistent esophageal inflammation and studies proposed to correlate histologic esophagitis on endoscopic biopsy with relapse frequency after cessation of medical therapy. Also, defects in epithelial defense are sought by PD measurements during acid perfusion in asymptomatic elderly Caucasian males, a group at high risk for RE, and if found, to determine if the defect is in the barrier, and age or genetics related. Another goal is to use morphology (epifluorescence/confocal microscopy, freeze fracture, TEM, immunocytochemistry), Ussing chambers and SDS-PAGE technology, to study the structure/function of the ICJs in healthy EE and to assess the mechanisms of H+ damage. This effort coupled with the studies above should provide new insights into the pathogenesis of RE.

该提案的长期目标是了解人类疾病的发病机理，反流食管炎（re），这是机械师和从目标组织的相对罕见的有利位置接近的食管上皮（EE）。在这笔赠款中，我们专注于EE的障碍属性，尤其是细胞间连接（ICJS）。 ICJ非常重要，这是针对H+进入EE的重要辩护，作为 H+攻击和损害最终导致食管炎的初始目标。因此，一个主要目标是表征使用IN的离子和分子的屏障特性，使用腔，顶端细胞膜（ACM）和ICJS使用IN 在使用腔室中的体外兔EE，并确定暴露于腔内酸是如何改变这些特性的。此外，自从许多RE的患者在pH监测时具有正常的酸接触时间，在室内EE的实验是旨在鉴定回流，餐和食管炎症反应中的（非酸性）因素将H+进入EE的障碍和确定的障碍物打破障碍，以将作用部位定位到ACMS 和/或ICJS，并通过pH-微电极降低PHI的能力来表征。此外，有证据表明，有RE的患者（上皮）屏障功能缺陷，并且那些非弱性食管炎的人局限于ICJ。由于本次本次组织本地化是验证的关键我们提出的对胃灼热和食道炎的发病机理，另一个目标是确认，使用体内PD测量在盐的超丝体期间，该缺陷位于ICJ。此外，随之而来的复发率很高医疗疗法和初步数据表明，这归因于EE内的持续缺陷。因此，我们假设这些缺陷是由于持续性食管炎症引起的，并提出了将组织学相关的研究停止医疗治疗后，内窥镜活检的食管炎。另外，上皮缺陷在无症状的老年高加索男性中，通过PD测量在酸灌注过程中寻求防御，这是一组 RE的高风险（如果发现），以确定缺陷是否在屏障中以及与年龄或遗传学有关的情况下。另一个目标是使用形态（落荧光/共聚焦显微镜，冻结，TEM，免疫细胞化学），使用Chambers和SDS-PAGE技术，以研究ICJS的结构/功能健康的EE并评估H+损伤的机制。加上上面的研究应提供的这项努力应提供对RE的发病机理的新见解。