ER-Mitochondrial Control of Acute Lung Injury

急性肺损伤/急性呼吸窘迫综合征（ALI/ARDS）是呼吸衰竭的常见原因， 重症患者，每年约有200，000名美国人受到折磨，其中约75，000人死亡，360万人住院 天ALI的标志是血管功能障碍，其特征在于内皮细胞（EC）炎症和 屏障破坏导致炎性浸润、间质水肿、肺泡灌流，最终 呼吸衰竭目前所有治疗ALI/ARDS的方法都依赖于支持性护理来改善临床结局。没有 已经研制出有效的药物。因此，迫切需要开发新的治疗策略， 安全、有效，并基于对ALI相关机制的更深入理解的ALI/ARDS 发病机制我们的长期目标是确定可行的治疗靶点和机制，以限制ALI。的 本申请的目的是确定ER分子伴侣BiP（免疫球蛋白重链结合）的作用 蛋白）和线粒体伴侣死亡蛋白介导的EC屏障功能障碍和炎症， 评估靶向这些分子对ALI的治疗益处。这个提议是根据我们的小说 这些发现暗示BiP和mortalin在介导炎症信号和屏障中起重要作用， 在ALI小鼠模型中EC和肺PMN浸润以及血管渗漏的破坏。我们令人鼓舞的数据 显示BiP或死亡蛋白药理学抑制剂各自保护免于肺损伤。然而，有趣的是， BiP和死亡蛋白的组合抑制在每种抑制剂的低得多的剂量（其单独 显示无保护作用）在保护小鼠免受LPS诱导的肺损伤和死亡方面的作用。这些令人兴奋 研究结果使我们假设BiP和mortalin是ALI的关键决定因素， 促进EC渗透性和炎症，BiP和死亡蛋白联合抑制可能证明 非常有效的治疗干预来控制ALI。该提案将针对以下目标。要求1 将确定（i）BiP调节EC渗透性和炎症的机制和（ii）BiP的体内作用。 内皮BiP引起肺部炎症和损伤。目标2将确定（一） 死亡蛋白调节EC渗透性和炎症，以及（ii）内皮死亡蛋白在引起肺损伤中的体内作用。 炎症和损伤。目标3将评估同时靶向的预防和治疗潜力 （联合抑制）BiP和mortalin对小鼠的ALI和死亡率。这些研究将利用 细胞、分子、生物化学、药理学、成像、体内基因转移和肺 physiology.体外和体内研究的创造性整合将提供对BiP的新见解， 在ALI过程中，mortalin调节EC炎症和渗透性，可能导致新的治疗方法 控制ALI/ARDS。

Acute lung Injury/Acute Respiratory Distress Syndrome (ALI/ARDS) is a common cause of respiratory failure in critically ill patients, and afflicts ~200,000 Americans each year with ~75000 deaths and 3.6 million hospital days. The hallmark of ALI is vascular dysfunction characterized by endothelial cell (EC) inflammation and barrier disruption resulting in inflammatory infiltrates, interstitial edema, alveolar flooding, and ultimately respiratory failure. All current therapies for ALI/ARDS rely on supportive care to improve clinical outcome. No effective drugs have been developed. Thus, there is an urgent need to develop new treatment strategies for ALI/ARDS that are safe, effective, and based on deeper understanding of the mechanisms involved in ALI pathogenesis. Our long-term goal is to identify viable therapeutic targets and mechanisms to limit ALI. The objective of this application is to determine the role of ER chaperone BiP (immunoglobulin heavy chain binding protein) and mitochondrial chaperone mortalin in mediating EC barrier dysfunction and inflammation in ALI and assess the therapeutic benefit of targeting these molecules against ALI. The proposal is based on our novel findings that implicate an important role for BiP and mortalin in mediating inflammatory signaling and barrier disruption in EC and lung PMN infiltration and vascular leak in a mouse model of ALI. Our encouraging data show that pharmacological inhibitor of BiP or mortalin each protects against lung injury. Intriguingly, however, the combined inhibition of BiP and mortalin is effective at much lower dosage of each inhibitor (which alone shows no protective effect) in protecting against LPS-induced lung injury and mortality in mice. These exciting findings have led us to the hypothesis that BiP and mortalin are critical determinants of ALI by their ability to promote EC permeability and inflammation, and that combined inhibition of BiP and mortalin may prove a highly efficacious therapeutic intervention to control ALI. The proposal will address the following aims. Aim 1 will determine (i) the mechanism of BiP regulation of EC permeability and inflammation and (ii) in vivo role of endothelial BiP in causing lung inflammation and injury. Aim 2 will determine (i) the mechanism by which mortalin regulates EC permeability and inflammation and (ii) in vivo role of endothelial mortalin in causing lung inflammation and injury. Aim 3 will evaluate the preventive and therapeutic potential of simultaneous targeting (combined inhibition) of BiP and mortalin against ALI and mortality in mice. These studies will utilize a combination of cellular, molecular, biochemical, pharmacological, imaging, in vivo gene transfer, and lung physiology. The creative integration of in vitro and in vivo studies will provide novel insights into BiP and mortalin regulation of EC inflammation and permeability during ALI and may lead to novel therapeutic interventions to control ALI/ARDS.