Aging and ARDS: Novel Mechanistic Role of Nox4/D in Age-Dependent Barrier Dysfunction

衰老与 ARDS：Nox4/D 在年龄依赖性屏障功能障碍中的新机制作用

• 批准号: 10485562
• 负责人: LOUISE HECKER
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10485562
• 关键词: Acute; Acute Lung Injury; Acute Respiratory Distress Syndrome; Age; Aging; Antioxidants; COVID-19 pandemic; COVID-19 patient; Cause of Death; Cells; Clinical Trials; Data; Development; Disease; Eko; Elderly; Endothelial Cells; Endothelium; Enzymes; Exhibits; FDA approved; Failure; Functional disorder; Generations; Genetic; Impairment; Incidence; Inflammatory; Inflammatory Response; Injury; Knock-out; Light; Link; Lung; Mediating; Molecular Weight; Mus; Mutagenesis; NADPH Oxidase; Outcome; Oxidants; Oxidation-Reduction; Oxidative Stress; Pathogenesis; Pathologic; Patient-Focused Outcomes; Patients; Permeability; Pharmacotherapy; Phenotype; Plasma; Play; Population; Post-Translational Protein Processing; Predisposition; Production; RNA Splicing; Reactive Oxygen Species; Reporting; Resolution; Role; Severities; Signal Transduction; Source; System; Testing; Therapeutic; Tissues; Ubiquitin; Variant; age related; aged; cohort; epidemiologic data; high risk population; improved; improved outcome; in vivo; insight; lung injury; military veteran; mortality; multicatalytic endopeptidase complex; novel; novel marker; overexpression; oxidative damage; pharmacologic; pre-clinical; prognostic indicator; response; sample collection; senescence; survival outcome; therapeutic development; therapy development

The mortality rate for acute respiratory distress syndrome (ARDS) remains unacceptably high (35-40%), and there are no FDA-approved drug treatments. Overwhelming data demonstrate that ARDS patient outcomes are significantly worse among the elderly population. However, we do not yet understand the mechanisms that account for this age-associated predisposition. The NADPH oxidase (Nox) enzymes are an important cellular source of reactive oxygen species (ROS) generation and signaling. We previously demonstrated that Nox4-dependent ROS plays a critical role in mediating endothelial cell (EC) barrier function during acute responses to lung injury. However, a growing body of evidence supports a link between excessive Nox4-derived ROS and numerous age-related diseases. We have demonstrated that in response to lung injury, aged mice exhibit persistently elevated Nox4/ROS levels that result in susceptibility to severe pre-clinical ARDS and failure to resolve injury. We discovered highly divergent induction of Nox4/ROS in “young” control vs. senescent ECs; control ECs exhibit a rapid and transient induction of Nox4, whereas senescent ECs exhibit persistently elevated levels of Nox4/ROS ROS leading to impaired barrier function. We identified a novel mechanism by which Nox4 expression can be rapidly altered in ECs via post-translational modification. Further, senescent ECs exhibit defective ubiquitin-mediated degradation of Nox4, which promotes sustained Nox4/ROS levels. Finally, we identified a small molecular weight splice variant of Nox4 (Nox4D) to be expressed only in the lungs of aged mice with severe pre-clinical ARDS and in the lungs of ARDS patients from 3 different cohorts. Finally, targeting of Nox4/D-dependent ROS in senescence/aging provided the most significant therapeutic benefit (as compared to young), and may be the key to improving outcomes for elderly ARDS patients. The proposed studies will test the central hypothesis that age-dependent persistent Nox4/D expression promotes redox imbalance leading to senescence- associated barrier disruptive EC phenotypes and greater inflammatory injury, ultimately resulting in the increased susceptibility and impaired resolution of ARDS in aging. Aim 1 studies will determine the role of Nox4 in mediating age-dependent barrier disruptive EC phenotypes and severity/resolution of pre-clinical ARDS. Aim 2 studies will investigate the association of Nox4D in ARDS patients and its functional role in ALI in vivo. Aim 3 studies will evaluate post-translational mechanisms contributing to the persistence of Nox4/D in senescent ECs. The proposed studies will provide insight into the roles of Nox4/D in regulating EC barrier and inflammatory responses, and how age-dependent dysfunction of Nox4/D contributes to ARDS pathogenesis. These studies will offer a novel mechanistic link that may help to explain the increased incidence and mortality of ARDS associated with the elderly and will provide proof-of-concept for therapeutic development.

急性呼吸窘迫综合征（ARDS）的死亡率仍然不可接受（35-40％）， 并且没有FDA批准的药物治疗。压倒性的数据表明ARDS患者 在老年人群中的结果明显更糟。但是，我们还不了解 解释了与年龄相关的倾向的机制。 NADPH氧化酶（NOX）酶是 活性氧（ROS）产生和信号传导的重要细胞来源。我们以前 证明NOX4依赖性ROS在介导内皮细胞（EC）屏障中起关键作用 急性反应对肺损伤的功能。但是，越来越多的证据支持 过多的NOX4衍生的ROS和许多与年龄有关的疾病。我们已经证明了这一点 对肺损伤的反应，老年小鼠持续升高NOX4/ROS水平，导致 对严重的临床前ARD的敏感性和无法解决伤害的敏感性。我们发现高度分歧 在“ Young”控制与Senscent EC中诱导NOX4/ROS；控制EC暴露了快速瞬态 NOX4的诱导，而感官EC持续暴露的NOX4/ROS ROS的水平持续升高 障碍功能受损。我们确定了一种新型机制，可以通过该机制快速改变NOX4的表达 通过翻译后修改在EC中。此外，感觉EC暴露于泛素介导的缺陷 NOX4的降解，促进NOX4/ROS水平持续。最后，我们确定了一个小分子 NOX4（NOX4D）的重量分裂变体仅在严重临床前的老年小鼠的肺中表达 ARDS和来自3个不同队列的ARDS患者的肺部。最后，靶向NOX4/D依赖性ROS 在感应/衰老中，提供了最显着的热益处（与年轻人相比），可能是 改善较早的ARDS患者预后的关键。拟议的研究将检验中心假设 年龄依赖性的持续性NOX4/D表达促进了氧化还原不平衡，从而导致感应 - 相关的屏障破坏性EC表型和更大的炎症性损伤，最终导致 增加的敏感性和衰老中ARDS的分辨率受损。 AIM 1研究将确定 NOX4在介导依赖年龄的屏障破坏性EC表型和临床前ARDS的严重性/解决方案中。 AIM 2研究将研究ARDS患者NOX4D的关联及其在体内ALI中的功能作用。 AIM 3研究将评估有助于NOX4/D在Senscent中持续存在的翻译后机制 ECS。拟议的研究将洞悉NOX4/D在调节EC障碍和炎症中的作用 反应以及NOX4/D的年龄依赖性功能障碍有助于ARDS发病机理。这些研究 将提供一种新型的机械链接，可能有助于解释ARDS的事件和死亡率的增加 与较旧的人相关，并将为治疗性发育提供概念验证。