Functional Role of HIF-PHDs in ARDS

项目总结 本应用旨在研究HIF-1α对缺氧诱导因子HIF1a的调节作用。 急性呼吸窘迫综合征(ARDS)期间的丙羟醛(PhDS)。ARDS是一种极端 由损伤或感染引起的肺部炎症反应。在外科患者中，ARDS可能发生在 大手术并导致发病率和死亡率急剧增加。此外，ARDS深刻地影响了 感染或败血症患者，包括最近的新冠肺炎大流行。然而，只有一小部分人 接受大手术或肺部感染的患者中，有8%的人会继续发展为ARDS。因此，我们 假设存在内源性适应性反应，以保护肺部免受严重的 导致ARDS的炎症。 我们实验室以前的研究证实，肺泡上皮细胞表达HIF1a是内源性的 ARDS时控制过度肺泡炎的反馈信号。当前应用程序的焦点是 博士生对HIF1a“上游”调控的研究。在缺氧或ARDS期间，PHD受到抑制， 从而促进高强度国际金融体系的稳定。已知三种PhD异构体(Phd1-3)。我们的初步研究 提示Phd1是肺中含量最丰富的PHD。应用机械通气诱导的研究进展 ARDS显示对PhD1有选择性抑制作用。此外，药物抑制PhD1或基因缺失 (Phd1-/-小鼠)与减少性肺损伤有关。此外，肺泡组织中PhD1基因缺失的小鼠 (Phd1loxp/loxP SPC Creer)在“常规”ARDS或感染SARS-CoV-2病毒期间受到保护。 对介导PhD1抑制的miRNAs的筛选表明，miR-15a/16是 在转录水平上受HIF1a诱导，并在ARDS期间有效地抑制PhD1。此外，过度表达 MiR-16在抑制PhD1和增强HIF1a稳定性的同时提供肺保护。 因此，我们假设依赖miR-15a/16的PhD1抑制和伴随的增强 HIF1a在内源性前馈环中稳定作用的研究 急性呼吸窘迫综合征期间的炎症。我们设计了四个目标来解决这个假设，包括Aim1，它是 重点研究miR15a/16和PhD1的相互作用，包括在ARDS患者中的原则证明研究。 在目标2中，我们将在常规ARDS模型中进行活体研究。在目标3中，我们正在扩大我们的研究范围 使用我们在UTHealth的BSL-3实验室建立SARS-CoV-2相关ARDS的体内模型。在目标4中， 我们将探索针对miR-15a/16-PhD1通路的ARDS治疗策略。 这些研究的成功完成将为我们推进临床试验提供科学基础。 针对个别博士或miR-15a/b预防或治疗外科患者或 经历病原体相关急性呼吸窘迫综合征的患者，例如在新冠肺炎期间。

PROJECT SUMMARY This application aims to investigate the regulation of hypoxia-inducible factor HIF1A by HIF- prolylhydroxyalses (PHDs) during acute respiratory distress syndrome (ARDS). ARDS is an extreme inflammatory response of the lungs triggered by injury or infection. In surgical patients, ARDS can occur after major surgery and causes dramatic increases in morbidity and mortality. Moreover, ARDS profoundly impacts patients with infections or sepsis, including the recent COVID-19 pandemic. However, only a minor percentage of patients who undergo major surgery or who have lung infections go on to develop ARDS. Therefore, we hypothesized that endogenous adaptive responses exist to protect the lungs from developing severe inflammation causing ARDS. Previous studies from our laboratory identified alveolar-epithelial expressed HIF1A as an endogenous feedback signal controlling excessive alveolar inflammation during ARDS. The current application is focused on examining the "upstream" regulation of HIF1A by PHDs. During hypoxia or ARDS, PHDs are inhibited, thereby promoting the stabilization of HIFs. Three PHD iso-forms are known (PHD1-3). Our preliminary studies indicate that PHD1 is the most abundant PHD in the lungs. Studies using mechanical ventilation to induce ARDS revealed selective repression of Phd1. In addition, pharmacologic inhibition of Phd1 or genetic deletion (Phd1-/- mice) is associated with attenuated lung injury. Moreover, mice with alveolar deletion of Phd1 (Phd1loxp/loxp SPC CreER+) are protected during "conventional" ARDS or infection with the SARS-CoV-2 virus. A screen for miRNAs that mediate PHD1-repression pointed us towards miR-15a/16. Indeed, miR-15a/16 is transcriptionally induced by HIF1A and effectively represses PHD1 during ARDS. In addition, overexpression of miR-16 provides lung protection in conjunction with PHD1 repression and enhanced HIF1A stabilization. Thus, we hypothesize that miR-15a/16-dependent repression of PHD1 and concomitant enhancement of HIF1A stabilization functions in an endogenous feedforward loop critical for attenuating alveolar inflammation during ARDS. We designed four aims to address this hypothesis, including Aim1, which is focused on the interaction of miR15a/16 and PHD1, including proof-of-principle studies in patients with ARDS. In Aim 2, we will pursue in vivo studies in conventional ARDS models. In Aim 3, we are extending our studies towards in vivo models of SARS-CoV-2-associated ARDS using our BSL-3 laboratory at UTHealth. In Aim 4, we will explore therapeutic strategies targeting the miR-15a/16-PHD1 pathway for ARDS treatments. Successful completion of these studies will give us the scientific foundation to move forward with clinical trials targeting individual PHDs or miR-15a/b towards the prevention or treatment of ARDS in surgical patients or patients experiencing pathogen-associated ARDS, such as during COVID-19.