Ethanol Prevents Microvascular Dysfunction

乙醇预防微血管功能障碍

• 批准号: 7036114
• 负责人: RONALD JOHN KORTHUIS
• 金额: $ 33.33万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-15 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7036114
• 关键词: alcoholic beverage consumption; antioxidants; biological signal transduction; calcitonin gene related peptide; cardiovascular disorder prevention; cell adhesion; cell cell interaction; chloride channels; cytochrome P450; enzyme activity; enzyme complex; enzyme induction /repression; ethanol; gene deletion mutation; genetically modified animals; inflammation; intravital microscopy; laboratory mouse; microcirculation; monoclonal antibody; nitric oxide; nitric oxide synthase; phenotype; protein localization; selectins; serine threonine protein kinase; vascular endothelium

DESCRIPTION (provided by applicant): Ethanol consumption at low to moderate levels protects the heart and vasculature from the deleterious effects of ischemia and reperfusion (I/R). Our recent work indicates that antecedent ethanol ingestion provokes the development of an anti-inflammatory phenotype in postcapillary venules such that these microvessels fail to support leukocyte/endothelial cell adhesive interactions during I/R. Surprisingly, AMP-activated kinase (AMPK) plays a necessary role in initiating this adaptive transformation to a protected phenotype in postcapillary venules. However, it is not clear how this enzyme, best known for its role as a metabolic master switch, is involved in transducing signals elicited by ethanol to effect the acquisition of tolerance to I/R in the microcirculation. Our overall hypothesis is that ethanol-induced, AMPK-dependent eNOS activation serves as an important initiating factor to trigger a cascade of signaling events that ultimately act to promote the expression of cytochrome P450 epoxygenases (CYP), which serve as an important effector of the beneficial microvascular actions of ethanol by catalyzing the formation of reaction products which exhibit powerful anti-adhesive and antioxidant properties. To address this postulate, we propose to determine whether: (1) ethanol-induced AMPK activation initiates the development of an anti-inflammatory phenotype by stimulating the formation of eNOS-derived NO; (2) NO-induced release of calcitonin gene-related peptide (CGRP) plays an essential role in the acquisition of tolerance to ischemia that is evoked by antecedent ethanol consumption; (3) the cystic fibrosis transmembrane regulator (CFTR) serves as an obligatory downstream signaling element that participates in inaugurating the development of the protected phenotype precipitated by ethanol-induced AMPK activation; and (4) ethanol-induced, AMPK-triggered increases in CYP activity during I/R prevents postischemic leukocyte adhesion in postcapillary venules by abrogating P-selectin expression. Intravital microscopic approaches will be used to quantify leukocyte rolling and adhesion in wild-type control mice and in mutant mice lacking AMPK, eNOS, CGRP, or CFTR. The influence of ethanol on l/R-induced adhesion molecule expression, AMPK and eNOS activity, CGRP release, and CYP protein expression and activity will also be investigated. Collectively, these aims address novel mechanisms whereby antecedent ethanol ingestion induces the development of an anti-inflammatory phenotype in postcapillary venules. This work will identify new links between ethanol-induced, AMPK-dependent, eNOS-derived NO formation as essential triggering elements, CGRP release and CFTR function as obligatory downstream mediators, and increased CYP activity as a major effector in the acquisition of tolerance to I/R by antecedent ethanol ingestion.

描述（由申请人提供）：低至中等水平的乙醇消耗可保护心脏和脉管系统免受缺血和再灌注（I/R）的有害影响。我们最近的工作表明，先前的乙醇摄入会引起毛细血管后微静脉中抗炎表型的发展，使得这些微血管在 I/R 期间无法支持白细胞/内皮细胞粘附相互作用。令人惊讶的是，AMP 激活激酶 (AMPK) 在毛细血管后微静脉中启动这种向受保护表型的适应性转变中发挥着必要的作用。然而，目前尚不清楚这种酶（以其作为代谢主开关的作用而闻名）如何参与转导乙醇引发的信号以影响微循环中 I/R 耐受性的获得。我们的总体假设是，乙醇诱导的、AMPK 依赖性 eNOS 激活是触发一系列信号事件的重要启动因素，最终促进细胞色素 P450 环氧化酶 (CYP) 的表达，而 CYP 是细胞色素 P450 环氧化酶 (CYP) 的重要效应子。乙醇通过催化反应产物的形成而发挥有益的微血管作用，这些反应产物具有强大的抗粘连和抗氧化特性。为了解决这个假设，我们建议确定是否：（1）乙醇诱导的 AMPK 激活通过刺激 eNOS 衍生的 NO 的形成来启动抗炎表型的发展； (2) NO诱导的降钙素基因相关肽(CGRP)的释放在获得对先前乙醇消耗引起的缺血耐受性中起着重要作用； (3) 囊性纤维化跨膜调节因子 (CFTR) 作为必需的下游信号元件，参与乙醇诱导的 AMPK 激活所促成的受保护表型的发展； (4) I/R期间乙醇诱导的、AMPK触发的CYP活性增加通过消除P-选择素表达来防止毛细血管后微静脉中缺血后白细胞粘附。活体显微镜方法将用于量化野生型对照小鼠和缺乏 AMPK、eNOS、CGRP 或 CFTR 的突变小鼠中的白细胞滚动和粘附。还将研究乙醇对 l/R 诱导的粘附分子表达、AMPK 和 eNOS 活性、CGRP 释放以及 CYP 蛋白表达和活性的影响。总的来说，这些目标解决了先前摄入乙醇诱导毛细血管后微静脉抗炎表型发展的新机制。这项工作将确定乙醇诱导的、AMPK 依赖性的、eNOS 衍生的 NO 形成（作为必需的触发元件）、CGRP 释放和 CFTR 功能（作为必需的下游介质）以及增加的 CYP 活性（作为获得 I 耐受性的主要效应器）之间的新联系。 /R 通过先前的乙醇摄入。