REGULATION OF ENDOTHELIAL CELL PERMEABILITY BY RHO/ROCK SIGNALING

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 微血管高通透性是失血性休克相关炎症的标志。尽管酒精中毒导致了三分之一的意外死亡，近50%的急诊室患者的血液酒精浓度为正，但还没有关于酒精中毒如何影响正常的微血管交换或体内创伤或炎症导致的微血管泄漏的研究。需要更好地了解微循环如何适应酒精中毒，以改进复苏和预防浮肿、失控炎症和感染的策略。我们实验室的研究表明，内皮细胞之间的细胞骨架和黏附连接在维持正常屏障功能和在全身炎症过程中作为高通透性反应的效应者都发挥着重要作用。我们的初步数据显示，急性酒精暴露破坏了内皮细胞肌动蛋白细胞骨架和细胞间连接。我们还观察到酒精给药加剧了体内对炎症刺激的高通透性反应。这些事件似乎涉及全身和局部(内皮细胞)水平的氧化应激。因此，我们假设酒精通过引起内皮细胞氧化应激介导的细胞骨架重排、减弱连接和对炎症刺激的夸大反应来加剧失血性休克引起的微血管渗漏。为了验证这一假说，中间的具体目的将是：1)表征急性酒精中毒和失血性休克复合过程中微血管屏障的异常，这将提供目前尚不能获得的体内数据；2)测试酒精中毒和失血性休克复合过程中酒精诱导的氧化应激的作用；以及3)研究内皮细胞骨架破坏在酒精中毒和失血性休克复合过程中微血管屏障功能障碍中的作用。这些中间目标将使用固定压力出血模型和急性酒精给药相结合来解决。利用活体肠系膜微循环的活体显微镜、建立的隔离灌流小静脉技术和分子生物学方法将成功地完成这项研究。这项研究获得的数据将为研究休克时微血管渗漏的机制提供新的见解。这些研究的最终目标是促进休克患者更好的复苏方法的发展。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Microvascular hyperpermeability is a hallmark of inflammation associated with hemorrhagic shock. Despite the fact that alcohol intoxication contributes to one-third of accidental deaths and that nearly 50% of emergency room patients have positive blood alcohol concentrations, there have been no studies of how alcohol intoxication affects normal microvascular exchange or microvascular leak caused by trauma or inflammation in vivo. A better understanding of how the microcirculation functionally adapts to alcohol intoxication is needed to improve strategies for resuscitation and prevention of edema, uncontrolled inflammation, and infection. Studies from our laboratory have shown that the cytoskeleton and adherens junctions between endothelial cells play important roles in both the maintenance of normal barrier function and as effectors of the hyperpermeability response during systemic inflammation. Our preliminary data show that acute alcohol exposure disrupts the endothelial actin cytoskeleton and intercellular junctions. We have also observed that alcohol administration exacerbates the in vivo hyperpermeability reaction to inflammatory stimuli. These events appear to involve oxidative stress at both the systemic and local (endothelial cell) level. Thus, we hypothesize that alcohol exacerbates hemorrhagic shock-induced microvascular leakage by causing oxidative stress-mediated cytoskeletal rearrangement in endothelial cells, weakening junctions and creating an exaggerated response to inflammatory stimuli. To intermediate specific aims to test this hypothesis will be to: 1) characterize microvascular barrier abnormalities during combined acute alcohol intoxication and hemorrhagic shock, which will provide in vivo data not currently available, 2) test the role of alcohol-induced oxidative stress during combined alcohol intoxication and hemorrhagic shock, and 3) examine the role of endothelial cytoskeletal disruption in microvascular barrier dysfunction during combined alcohol intoxication and hemorrhage. These intermediate aims will be addressed using a fixed pressure hemorrhage model combined with acute alcohol administration. An integrated approach utilizing in vivo intravital microscopy of the mesenteric microcirculation, an established isolated perfused venule technique, and molecular biology methods will be used to successfully complete this study. The data obtained from this study will provide new insights into the mechanisms underlying microvascular leakage during shock. The ultimate goal of these studies is to promote development of better resuscitation methods for shock patients.