Heat shock and lung fluid balance

这个新的赠款周期的目标是确定如何激活应激蛋白反应（SPR） 在急性肺损伤中保护肺泡毛细血管屏障的完整性（All）。因此，我们开发了一个 大鼠和小鼠中缺血-再灌注（I/R）介导的肺损伤模型作为临床相关的 所有.在初步实验中，SPR激活抑制血管内皮生长因子（VEGF） 介导的肺内皮渗漏，并阻止iNOS/NO介导的抑制肺泡水肿的消除 I/R损伤后肺上皮细胞的变化。我们将检验SPR激活抑制 这两种细胞信号传导途径（VEGF，JAK/Stat 1诱导的iNOS/NO）通过：（a）首先通过立即的 Hsp 90与其客户蛋白的解离是这两种信号传导途径的关键部分，因此 使它们失去功能，然后（B）通过从头合成热休克蛋白，如Hsp 70， 与Hsp 90客户蛋白结合并阻止其聚集和蛋白酶体降解，直到Hsp 90 可以与蛋白质重新复合。在aim 1中，我们将对分子机制提供新的见解 解释SPR激活如何抑制VEGF依赖性细胞信号传导，导致肺内渗漏 内皮屏障在目标2中，我们将研究SPR激活如何通过以下方式恢复正常的肺泡液体转运： 抑制JAK/Stat 1诱导的iNOS依赖性NO释放在基底节和 cAMP调节的离子和液体转运通过肺上皮。在目标3中，我们将确定体内 SPR介导的VEGF诱导的肺血管通透性增加的抑制与 一氧化氮介导的大鼠/小鼠肺泡上皮细胞液体转运和蛋白通透性的损害 从这些实验中获得的信息对I/R损伤的治疗具有重要意义。 意义事实上，应激反应可以使用安全的药物激活， 作为早期预防性治疗，保护患者免受肺移植中I/R肺损伤，严重 创伤或术中缺血引起休克。本申请将提供新的信息来解释 细胞对压力的反应如何保护肺部免受血流缺乏造成的伤害。的 研究结果可能有助于确定新的细胞靶点，以开发治疗方法， 保护创伤和肺移植患者免受急性肺损伤

The goal of this new grant cycle is to determine how the activation of the stress protein response (SPR) protects the integrity of the alveolar capillary barrier in acute lung injury (All). We therefore developed a model of ischemia-reperfusion (l/R)-mediated lung injury in rats and mice as a clinically relevant model of All. In preliminary experiments, SPR activation inhibited the vascular endothelial growth factor (VEGF) mediated lung endothelial leak and prevented the iNOS/NO-mediated inhibition of alveolar edema removal by the lung epithelium after onset of I/R injury. We will test the central hypothesis that SPR activation inhibits these two cell signaling pathways (VEGF, JAK/Stat1-induced iNOS/NO) by: (a) first by an immediate dissociation of Hsp90 from its clients proteins that are critical part of these two signaling pathways, thus rendering them nonfunctional, then (b) by a de novo synthesis of heat shock proteins, such as Hsp70, that binds to Hsp90 client proteins and prevents their aggregation and proteasomal degradation until the Hsp90 can re-complex with the proteins. In aim 1, we will provide new insights into the molecular mechanisms explaining how SPR activation inhibits VEGF-dependent cell signaling that causes the leakage in the lung endothelial barrier. In aim 2 , we will examine how SPR activation restores normal alveolar fluid transport by inhibiting the effect of JAK/Stat1-induced iNOS-dependent NO release in the airspaces on the basal and cAMP-regulated ion and fluid transport across the lung epithelium. In aim 3, we will determine the in vivo relevance of the SPR-mediated inhibition of the VEGF-induced increase in lung vascular permeability and NO-mediated impairment of alveolar epithelial fluid transport and protein permeability in a rat/mouse model of I/R injury.The information that will be obtained from these experiments has an important therapeutic significance. Indeed, the stress response could be activated using pharmacological agents that are safe in humans as an early prophylactic therapy and protect patients from I/R lung injury in lung transplants, severe shock from trauma or intraoperative ischemia. The present application will provide new information to explain how the cellular response to stress may protect the lungs against injury caused by the lack of blood flow. The results of studies may help to to identify new cellular targets for the development of treatments that will protect trauma and lung transplant patients from acute lung injury