ecSOD derived peroxide in pulmonary adaptation to hypoxia

ecSOD 衍生的过氧化物在肺适应缺氧中的作用

• 批准号: 9102162
• 负责人: Michael S Wolin
• 金额: $ 40.25万
• 依托单位: NEW YORK MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-16 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9102162
• 关键词: Acute; Animal Model; Animals; Arteries; Attenuated; Blood Vessels; Cardiopulmonary; Chronic; Chronic Obstructive Airway Disease; Cyclic GMP; Cysteine; Data; Development; Dimerization; Disease Progression; Exposure to; Generations; Genetic; Health; Heart failure; Human; Hydrogen Peroxide; Hypoxia; In Vitro; Information Systems; Knock-in Mouse; Lung; Mediating; Modification; Mus; NOS3 gene; Nitric Oxide; Oxidation-Reduction; Oxygen; Peroxides; Phosphorylation; Process; Property; Protein Kinase; Pulmonary Hypertension; Pulmonary artery structure; Reactive Oxygen Species; Regulation; Regulator Genes; Relaxation; Role; Serine; Signal Transduction; Sleep Apnea Syndromes; Smooth Muscle; Sulfhydryl Compounds; Superoxides; System; Therapeutic; Tissues; Vascular Smooth Muscle; Work; base; catalase; extracellular; heme oxygenase-1; in vivo; overexpression; oxidation; prevent; protective effect; response; src-Family Kinases; vasoconstriction

DESCRIPTION (provided by applicant): The central hypothesis of this project is that extracellular SOD (ecSOD) activity has potentially beneficial important roles in controlling the expression of pulmonary hypertension resulting from exposure to chronic hypoxia through the generation of hydrogen peroxide and its stimulation of cGMP protein kinase (PKG). It is also hypothesized that increased expression of ecSOD is a process that contributes to the protective effects of heme oxygenase-1 (HO-1) elevation in pulmonary hypertension. While there is substantial evidence for HO-1 and ecSOD being beneficial in attenuating the development of pulmonary hypertension in several animal models, previous studies do not appear to have considered the mechanisms investigated in this application. Our recent studies document that peroxide can promote activation of PKG by a thiol oxidation-mediated PKG subunit dimerization mechanism which participates in relaxation of pulmonary arteries to extracellular hydrogen peroxide and responses to acute hypoxia. Preliminary data provide evidence that chronic hypoxia in vivo promotes both a dimerization activation of PKG and a suppression of force generation in isolated mouse pulmonary arteries by a process that is reversible by catalase. The studies proposed focus on using mice deficient in ecSOD or HO-1, a PKG knockin mouse that is modified to prevent thiol oxidation-activation of PKG by peroxide together with beneficial pulmonary hypertension therapies that increase ecSOD or HO-1 expression and promote PKG dimerization to investigate their roles in controlling the adaptation of pulmonary vascular function caused by exposure of mice to chronic hypoxia. Studies in Aim 1 define the influence of changes in ecSOD expression on processes contributing to the control of vascular function and remodeling involved in the development and reversal of hypoxia-induced pulmonary hypertension by utilizing mice either overexpressing or deficient in ecSOD. Aim 2 focuses on defining how ecSOD expression functions through either increased peroxide regulation of PKG and/or through increased superoxide scavenging to increase nitric oxide (NO) utilizing PKG knockin mice which have a modification preventing PKG dimerization and mice deficient in endothelial nitric oxide synthase (eNOS). The focus of studies in Aim 3 is defining the influence of changes in ecSOD expression on the protective effects of HO-1 utilizing mice deficient in HO-1 or ecSOD and therapies to induce HO-1 and ecSOD. Studies will include ECHO-Doppler flow analysis of cardiopulmonary function, mechanistic functional studies in isolated pulmonary arteries, signaling studies related to PKG and processes influencing the redox regulation src kinase-mediated STAT-3 phosphorylation promoting expression of miR-204, a master gene regulatory system controlling the development and reversal of smooth muscle remodeling in pulmonary hypertension. These studies should provide definitive new mechanistic information on how the effects of chronic hypoxia promote the development of pulmonary hypertension, which could be beneficial in treating the progression of diseases such as COPD and sleep apnea.

描述（由申请人提供）：本项目的中心假设是细胞外SOD（ecSOD）活性通过产生过氧化氢及其刺激cGMP蛋白激酶（PKG）在控制暴露于慢性缺氧导致的肺动脉高压表达方面具有潜在的有益重要作用。也有人假设，增加ecSOD的表达是一个过程，有助于血红素加氧酶-1（HO-1）升高肺动脉高压的保护作用。虽然有大量证据表明HO-1和ecSOD在几种动物模型中有益于减轻肺动脉高压的发展，但以前的研究似乎没有考虑本申请中研究的机制。我们最近的研究表明，过氧化物可以通过巯基氧化介导的PKG亚基二聚化机制促进PKG的活化，该机制参与肺动脉对细胞外过氧化氢的舒张和对急性缺氧的反应。初步数据提供的证据表明，慢性缺氧在体内促进PKG的二聚化激活和抑制力产生在离体小鼠肺动脉的过程是可逆的过氧化氢酶。提出的研究集中于使用ecSOD或HO-1缺陷的小鼠，PKG敲入小鼠，其经修饰以防止过氧化物对PKG的巯基氧化-活化，以及增加ecSOD或HO-1表达并促进PKG二聚化的有益的肺动脉高压疗法，以研究它们在控制由小鼠暴露于慢性缺氧引起的肺血管功能适应中的作用。目的1中的研究通过利用过度表达或缺乏ecSOD的小鼠，确定了ecSOD表达变化对有助于控制血管功能和重塑的过程的影响，这些过程涉及低氧诱导的肺动脉高压的发展和逆转。目的2着重于定义ecSOD表达如何通过增加PKG的过氧化物调节和/或通过增加超氧化物清除以增加一氧化氮（NO）利用PKG敲入小鼠（其具有防止PKG二聚化的修饰）和内皮型一氧化氮合酶（eNOS）缺陷的小鼠发挥功能。目的3的研究重点是利用HO-1或ecSOD缺陷的小鼠和诱导HO-1和ecSOD的治疗来确定ecSOD表达的变化对HO-1保护作用的影响。研究将包括心肺功能的ECHO-多普勒血流分析、离体肺动脉中的机械功能研究、PKG相关信号研究以及影响氧化还原调节src激酶介导的STAT-3磷酸化促进miR-204表达的过程，miR-204是控制肺动脉高压中平滑肌重塑发展和逆转的主基因调节系统。这些研究应该提供关于慢性缺氧的影响如何促进肺动脉高压发展的明确的新机制信息，这可能有利于治疗COPD和睡眠呼吸暂停等疾病的进展。