Amplification Mechanisms of Lung Endothelial Inflammation During Acute Lung Injury

项目摘要/摘要 内毒素血症和败血症所致的肺功能衰竭可导致广泛且通常迅速的肺血管内皮细胞损伤。 中性粒细胞和巨噬细胞等炎性细胞不受限制地涌入。这种适应不良的炎症性疾病 反应超过了肺的修复能力，导致严重的炎症性肺损伤和低氧血症。 这项建议侧重于不适应性炎症的基本放大机制。 肺内皮细胞的激活。我们的中心假设是对威胁的炎症反应发出了这样的信号 作为细菌脂多糖对血管内皮细胞质膜的初始破坏和快速释放 线粒体DNA被损伤的线粒体大量和剧烈地进入胞浆放大炎症 因此，它是急性肺损伤(ALI)进展的重要前馈机制。在AIM 1，我们将确定最近发现的穿孔素Gasdermin D介导的机制 血管内皮细胞膜孔形成与K+外流通道激活机制 我们最近发现了两个。我们将讨论放大K+外流在严重程度和 内皮细胞NLRP3炎性小体激活与暴发性肺损伤在目标2中，我们将定义 另一个关键的扩增机制是Gasdermin D介导的潜在重要作用 线粒体(Mt)膜孔的形成和mtDNA的释放，这也可能是灾难性的 通过激活I型干扰素信号放大肺损伤。这些机械驱动的研究将利用 遗传小鼠模型(我们实验室中的内皮特异性基因敲除模型)以及全面的成像， 电生理和生理学方法，从而为鉴定新的内皮细胞提供了框架 导致肺血管损伤和ALI的放大炎症机制。我们将阐明这些因素是如何 可以有针对性地通过通路减少组织损伤，提高存活率。

PROJECT SUMMARY / ABSTRACT Lung failure from endotoxemia and sepsis induces widespread and often rapid lung vascular endothelial injury due to unfettered influx of inflammatory cells such as neutrophils and macrophages. This maladaptive inflammatory response outpaces the reparative capacity of lungs, resulting in profound inflammatory lung injury and hypoxemia. This proposal focuses on fundamental amplification mechanisms underlying the maladaptive inflammatory activation of the lung endothelium. Our central hypothesis is that the inflammatory response to threat signals such as the initial breaching of the endothelial plasma membrane by bacterial lipopolysaccharide (LPS) and rapid release of mitochondrial DNA by the injured mitochondria into the cytosol massively and acutely amplifies the inflammatory response and thus serves as essential feed-forward mechanisms for progression of acute lung injury (ALI). In Aim 1, we will determine the mechanisms by which the recently identified perforin Gasdermin D mediates endothelial plasma membrane pore formation and the mechanisms of activation of the K+ efflux ion channel TWIK2 that we have recently identified. We will address the role of amplifying K+ efflux on the severity and rapidity of endothelial NLRP3 inflammasome activation and fulminant lung injury. In Aim 2, we will define another crucial amplification mechanism, the potentially important role of Gasdermin D-mediated mitochondrial (mt) membrane pore formation and the release of mtDNA, which may also catastrophically amplifiy lung injury via activation of Type I interferon signaling. These mechanistically driven studies will utilize genetic mouse models (endothelial specific knockout models in our labs) as well as comprehensive imaging, electrophysiological and physiological approaches and thus provide the framework for identifying novel endothelial amplification inflammatory mechanisms that induce lung vascular injury and ALI. We will elucidate how these pathways can be targeted to reduce tissue damage and improve survival.