Heat shock and lung fluid balance

这一新的拨款周期的目标是确定应激蛋白反应(SPR)的激活 在急性肺损伤(ALL)中保护肺泡毛细血管屏障的完整性。因此，我们开发了一种 大鼠和小鼠肺缺血再灌注损伤模型的建立及其临床意义 全。在初步实验中，SPR的激活抑制了血管内皮生长因子(VEGF) 介导肺内皮细胞渗漏和拮抗iNOS/NO介导的抑制肺泡水肿清除 在I/R损伤发生后，肺上皮细胞受到损伤。我们将检验SPR激活抑制SPR的中心假设 这两条细胞信号通路(血管内皮生长因子、JAK/STAT1诱导的iNOS/NO)通过：(A)首先通过 Hsp90从其客户蛋白中解离，这些蛋白是这两个信号通路的关键部分，因此 使它们失去功能，然后(B)通过热休克蛋白的从头合成，如Hsp70， 结合Hsp90客户蛋白，防止其聚集和蛋白酶体降解，直到Hsp90 可以与蛋白质重新复合。在目标1中，我们将对分子机制提供新的见解。 解释SPR激活如何抑制导致肺渗漏的血管内皮生长因子依赖性细胞信号转导 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运输 抑制JAK/STAT1诱导的诱导型一氧化氮合酶依赖的NO释放对基础和 CAMP调节的跨肺上皮的离子和液体运输。在目标3中，我们将确定体内的 SPR介导的抑制血管内皮生长因子诱导的肺血管通透性增加与血管紧张素转换酶的关系 一氧化氮对大鼠/小鼠肺泡上皮液转运和蛋白通透性的影响 从这些实验中获得的信息将具有重要的治疗作用 意义。事实上，应激反应可以通过使用安全的药理制剂来激活。 人类作为早期预防治疗和保护患者肺移植中I/R肺损伤，严重 创伤或术中缺血所致休克。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因血流不足而造成的损伤。这个 研究结果可能有助于确定新的细胞靶点，用于开发将 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