Daily Moderate Ethanol Ingestion Attenuates Postischemic Microvascular Dysfunctio

描述（由申请人提供）：经常摄入低至中等水平的乙醇（EtOH）可以保护器官和微血管免受缺血和再灌注（I/R）的有害影响。最近，我们发现预先摄入乙醇通过一种新机制刺激抗炎表型的发展（减少炎症介质的缺血后形成，显著减弱粘附分子表达、氧化剂产生、白细胞滚动、粘附和迁出毛细血管后小静脉），该机制在存在心血管疾病共存危险因素的情况下仍然有效。令人惊讶的是，我们的工作揭示了在乙醇暴露期间促炎降钙素基因相关肽（CGRP）和肿瘤坏死因子（TNF）介导的中性粒细胞活化在启动这种适应性转化中的重要作用，当组织在EtOH后暴露于I/R 24小时时，这种转化在毛细血管后小静脉中变得明显。在目前的提案中，我们试图建立在这些基本观察的基础上，以评估每天适度的EtOH诱导感觉神经元释放trpv1依赖性CGRP的总体假设，这反过来激活CD4+ T淋巴细胞表达肿瘤坏死因子- (TNF)。依赖于tnf的中性粒细胞蛋白酶介导的间质信号的产生与内皮整合素v 3结合，诱导HO-1表达/活性增加，以限制缺血后微血管功能障碍。为了解决这一假设，我们建议确定以下因素的作用：(1)乙醇诱导的、依赖于cgrp的T淋巴细胞的激活，T淋巴细胞随后产生TNF来激活组织驻留的中性粒细胞，以蛋白水解产生信号，触发对前乙醇的抗炎表型的发展；(2)中性粒细胞蛋白酶启动，v 3整合素依赖增加HO-1的表达和活性，作为I/R期间抗炎表型的下游介质。活体显微方法将用于量化缺血后白细胞/内皮细胞的相互作用。EtOH是否能提高血浆和组织CGRP和TNF水平，诱导T细胞和中性粒细胞活化，增加HO-1的表达和活性，从而阻止I/ r诱导的内皮粘附分子和炎症介质的表达，我们也将进行研究。意义：这项工作将确定cgrp激活的T细胞、tnf激活的中性粒细胞的蛋白水解活性产生的信号以及通过预先摄入乙醇获得I/R耐受性的v - 3依赖性HO-1表达/活性之间的新联系。完成这些研究将为相关患者群体的转化疗法的发展提供机制基础。

DESCRIPTION (provided by applicant): Regular consumption of ethanol (EtOH) at low to moderate levels protects organs and microvasculature from the deleterious effects of ischemia and reperfusion (I/R). Recently, we discovered that antecedent ethanol ingestion provokes the development of an anti-inflammatory phenotype (reduced postischemic formation of inflammatory mediators and markedly attenuated adhesion molecule expression, oxidant production, and leukocyte rolling, adhesion, and emigration in postcapillary venules) via a novel mechanism that remains effective in the presence of co-existing risk factors for cardiovascular disease. Surprisingly, our work uncovered important roles for proinflammatory calcitonin gene-related peptide (CGRP) and tumor necrosis factor-� (TNF) mediated neutrophil activation during the period of ethanol exposure in initiating this adaptive transformation that becomes apparent in postcapillary venules when tissues are exposed to I/R 24 hrs after EtOH. In the current proposal, we seek to build on these fundamental observations to evaluate the overall hypothesis that daily moderate EtOH induces TRPV1-dependent CGRP release from sensory neurons, which in turn activates CD4+ T lymphocytes to express tumor necrosis factor-� (TNF). TNF-dependent, neutrophil proteasemediated generation of signals in the interstitium engage endothelial integrin �v�3 to induce increased HO-1 expression/activity to limit postischemic microvascular dysfunction. To address this postulate, we propose to determine the roles of: (1) EtOH-induced, CGRP-dependent activation of T lymphocytes, which subsequently produce TNF to activate tissue resident neutrophils to proteolytically generate signals that trigger the development of an anti-inflammatory phenotype in response to antecedent ethanol; and (2) neutrophil protease-initiated, �v�3 integrin-dependent increased HO-1 expression and activity as downstream mediators of the anti-inflammatory phenotype seen during I/R. Intravital microscopic approaches will be used to quantify postischemic leukocyte/endothelial cell interactions. The effects of EtOH to elevate plasma and tissue CGRP and TNF levels, induce T cell and neutrophil activation, and increase HO-1 expression and activity to prevent I/R-induced endothelial adhesion molecule and inflammatory mediator expression will also be investigated. Significance: This work will identify new links between CGRP-activated T cells, signals generated by the proteolytic activity of TNF-activated neutrophils, and �v�3-dependent HO-1 expression/activity in the acquisition of tolerance to I/R by antecedent ethanol ingestion. Completing these studies will provide the mechanistic basis for development of translational therapeutics in relevant patient populations.