Trek-1 Potassium Channels Protect from Hyperoxia-induced Acute Lung Injury

项目总结： 意义：氧气补充(高氧血症；HO)是最常用的治疗方法 是治疗急性缺氧性呼吸衰竭(ARF)的基石。众所周知， 然而，HO暴露不仅可以促进现有的肺损伤，而且还可以引发炎症和屏障 在其他方面健康的肺部出现功能障碍。由HO引起的炎症反应对 肺泡上皮细胞和内皮细胞导致细胞凋亡和肺泡屏障破坏。在临床上， 对HO诱导的急性肺损伤(HALI)的认识导致了人们对氧毒性和 努力将ARF患者的氧气暴露降至最低。尽管临床和实验研究已经确定 HALI的几种潜在机制，目前还没有预防或抵消HALI的治疗方法，以及 20年来，ARF患者的住院时间一直保持不变。这些发现 强调迫切需要确定分子靶标，以促进针对HALI的合理药物设计。 在寻找这种新的靶点的过程中，我们发现了Trek-1钾通道作为潜在的新的关键 哈里市的监管者。我们的初步数据支持新的假设，即HO下调上皮细胞和 内皮细胞Trek-1通道，导致细胞膜去极化，随后开放电压-1 门控钙通道，从而增加炎症介质的分泌，细胞凋亡和 肺泡屏障功能障碍。此外，我们认为增强Trek-1的活性可以抵消这一点 有害的瀑布。 我们将在三个具体目标中检验这一假设：在AIM1中，我们将主要确定细胞类型(-S) 受HO诱导的Trek-1下调的影响，使用上皮和内皮细胞特异性的Trek-1 KO小鼠 从这些小鼠中分离出模型和原代细胞。在目标2中，我们将确定Trek-1的保护作用 新型Trek-1激活化合物、新型细胞类型特异性Trek-1增强抗HALI作用 高表达的小鼠模型，以及从这些小鼠分离的原代上皮细胞和内皮细胞。在AIM 3中 我们将剖析上皮和内皮细胞Trek-1的结构组成和生物物理特性 在基线和HO条件下的通道，并提出了一种新的信号机制，Trek-1 HALI时，经络对炎症和屏障功能障碍有调节作用。 这项研究将通过建立异常上皮和内皮细胞Trek-1来影响急性肺损伤领域。 在HALI中，肺中的信号是一个以前未知的途径，Trek-1的激活是第一个靶点 针对哈里的治疗方法。

PROJECT SUMMARY: Significance: Oxygen supplementation (hyperoxia; HO) is the most frequently applied therapy for hospitalized patients and the cornerstone of treatment for acute hypoxic respiratory failure (ARF). It is well known, however, that HO exposure can not only promote existing lung injury but also initiate inflammation and barrier dysfunction in otherwise healthy lungs. The inflammatory response evoked by HO is particularly damaging to alveolar epithelial and endothelial cells causing cellular apoptosis and alveolar barrier disruption. Clinically, the recognition of HO-induced acute lung injury (HALI) led to an increased awareness of oxygen toxicity and efforts to minimize oxygen exposure for ARF patients. Although clinical and experimental studies have identified several potential mechanisms underlying HALI, currently no therapies exist to prevent or counteract HALI, and the length of hospitalization of ARF patients has remained unchanged for two decades. These findings underscore the urgent need for identifying molecular targets to facilitate rational drug design against HALI. In the search for such new targets, we discovered TREK-1 potassium channels as potential new key regulators of HALI. Our preliminary data support the novel hypothesis that HO downregulates epithelial and endothelial TREK-1 channels, which results in cell membrane depolarization, subsequent opening of voltage- gated Ca2+ channels, and as a consequence increased inflammatory mediator secretion, cell apoptosis and alveolar barrier dysfunction. Furthermore, we propose that enhancement of TREK-1 activity can counteract this injurious cascade. We will test this hypothesis in three Specific Aims: In Aim1 we will identify the cell type(-s) predominantly affected by HO-induced TREK-1 downregulation, using epithelial and endothelial cell-specific TREK-1 KO mouse models and primary cells isolated from these mice. In Aim 2 we will determine the protective effects of TREK-1 enhancement against HALI using novel TREK-1 activating compounds, new cell type-specific TREK-1 overexpressing mouse models, and primary epithelial and endothelial cells isolated from these mice. In Aim 3 we will dissect the structural composition and biophysical properties of epithelial and endothelial TREK-1 channels at baseline and under HO conditions, and propose a novel signaling mechanism by which TREK-1 channels could regulate inflammation and barrier dysfunction during HALI. This study will impact the field of acute lung injury by establishing aberrant epithelial and endothelial TREK- 1 signaling in the lung as a previously unrecognized pathway in HALI, and TREK-1 activation as the first targeted therapeutic approach against HALI.