Extracellular superoxide induces Egr-1 in the hypoxic pulmonary artery

细胞外超氧化物在缺氧肺动脉中诱导 Egr-1

• 批准号: 8197441
• 负责人: Eva S. Nozik
• 金额: $ 38.12万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-12-01 至 2013-08-19
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8197441
• 关键词: Animal Model; Antioxidants; Arteries; Automobile Driving; Biological Assay; Biological Models; Blood; Blood Vessels; Bolus Infusion; Bronchopulmonary Dysplasia; Cell Count; Cell Culture Techniques; Cell Proliferation; Cell membrane; Cells; Charge; Child; Child Development; Childhood; Chronic; Clinical Trials; Coagulation Process; Collagen; Complement; Complication; DNA Binding; Data; Deposition; Development; Employee Strikes; Equilibrium; Erythropoietin; Event; Excretory function; Exhibits; Fibroblasts; Foundations; Future; Gene Expression; Genes; Genetically Engineered Mouse; Goals; Grant; Growth; Hand; Health; Heart failure; Homeostasis; Human; Hydrogen Peroxide; Hypoxia; IL8 gene; In Vitro; Individual; Infant; Inflammation; Injury; Intravenous Bolus; Kidney; Knockout Mice; Laboratories; Life; Lung; Lung diseases; Measures; Medial; Membrane; Methods; Modeling; Molecular; Morbidity - disease rate; Mus; Myosin Heavy Chains; NADPH Oxidase; Neonatal; Nuclear; Outcome; Oxidants; Oxidation-Reduction; Pathologic; Patients; Pericytes; Phenotype; Population; Principal Investigator; Process; Production; Property; Protein Isoforms; Publishing; Pulmonary Circulation; Pulmonary Hypertension; Pulmonary artery structure; Pump; RNA; Reaction; Reactive Oxygen Species; Reperfusion Therapy; Reporter; Research; Risk; Role; SOD2 gene; Sampling; Series; Severities; Signaling Molecule; Smooth Muscle Myocytes; Smooth Muscle Myosins; Solid; Source; Stimulus; Superoxide Dismutase; Superoxides; System; Tacrolimus Binding Protein 1A; Testing; Thromboplastin; Tissues; Tunica Adventitia; Up-Regulation; Vascular remodeling; Wild Type Mouse; base; cell type; extracellular; immature animal; improved; in vivo; interstitial; knowledge base; lung hypoxia; lung injury; lung ischemia; mortality; mouse model; neonate; novel therapeutic intervention; overexpression; prevent; programs; promoter; protective effect; research study; response; tool; transcription factor

DESCRIPTION (provided by applicant): PA vascular remodeling with pulmonary hypertension is a life-threatening complication in infants and children with hypoxic lung diseases. A further understanding of this process is essential to develop new strategies aimed at reducing the severity of pulmonary hypertension in these individuals. Accumulating evidence indicates that reactive oxygen species (ROS), including superoxide (O2-) generated via NADPH oxidase, contribute to vascular remodeling. Extracellular oxidant/antioxidant homeostasis is maintained by the extracellular isoform of superoxide dismutase (EC-SOD), which is highly expressed in the vessel wall. The proposal tests the hypothesis that hypoxia disrupts the balance between the production of extracellular O2- by NADPH oxidase and its clearance by EC-SOD in the PA. We further hypothesize that excess extracellular O2- generated in the hypoxic lung upregulate a hypoxia-inducible and redox-sensitive transcription factor, early growth response-1 (Egr-1), which, in turn, stimulates Egr-1-responsive genes important in causing neonatal chronic hypoxia-induced pulmonary vascular remodeling and pulmonary hypertension. Aim 1 will use PA segments isolated from chronically hypoxic calves and mice and in vitro pulmonary artery vascular cells isolated from the neonatal calf to evaluate production of reactive oxygen species and expression and activity of EC-SOD. Aim 2 will use chronically hypoxic mice overexpressing and lacking EC-SOD as well as mice lacking gp91phox subunit of NADPH oxidase to provide in vivo molecular and pharmacologic evidence that extracellular O2- regulates critical hypoxia-responsive genes and contributes to chronic hypoxia-induced pulmonary vascular remodeling and pulmonary hypertension in the developing lung. To complement this model, in Aim 3, we will use the PA adventitial fibroblast isolated from the neonatal calf as a highly relevant model system for in vitro experiments to test the effects of hypoxia-induced extracellular O2- on the expression of the redox-sensitive transcription factor Egr-1. The study of chronic hypoxia as a stimulus for pulmonary vascular remodeling and pulmonary hypertension is compelling, as hypoxia is a common feature of diverse lung diseases. Thus, by advancing our knowledge base and testing new therapeutic approaches in animal models, we will provide a solid foundation for future human clinical trials in a range of scenarios associated with hypoxic lung diseases to improve health outcome for patients with these difficult and serious problems. PROJECT NARRATIVE: Hypoxia complicates severe lung diseases in infants and children, and the development of pulmonary vascular remodeling and pulmonary hypertension in these patients leads to right heart failure, greatly increasing morbidity and mortality. This proposal tests whether an imbalance in production and clearance of extracellular superoxide contributes to the structural remodeling in chronic hypoxic pulmonary hypertension. This proposal will provide the basis for future human clinical trials in a range of scenarios associated with hypoxic lung diseases to improve health outcome for pediatric patients with these difficult and serious problems.

描述（由申请人提供）：PA 血管重塑伴肺动脉高压是患有缺氧性肺病的婴儿和儿童的一种危及生命的并发症。进一步了解这一过程对于制定旨在降低这些个体肺动脉高压严重程度的新策略至关重要。越来越多的证据表明，活性氧 (ROS)，包括通过 NADPH 氧化酶产生的超氧化物 (O2-)，有助于血管重塑。细胞外氧化剂/抗氧化剂稳态由超氧化物歧化酶 (EC-SOD) 的细胞外亚型维持，该酶在血管壁中高度表达。该提案测试了以下假设：缺氧破坏了 PA 中 NADPH 氧化酶产生的细胞外 O2- 与 EC-SOD 清除的细胞外 O2- 之间的平衡。我们进一步假设，缺氧肺中产生的过量细胞外 O2- 会上调缺氧诱导和氧化还原敏感的转录因子，即早期生长反应 1 (Egr-1)，进而刺激 Egr-1 反应基因，这对于引起新生儿慢性缺氧诱导的肺血管重塑和肺动脉高压至关重要。目标 1 将使用从长期缺氧的小牛和小鼠中分离出的 PA 片段以及从新生小牛中分离出的体外肺动脉血管细胞来评估活性氧的产生以及 EC-SOD 的表达和活性。目标 2 将使用过度表达和缺乏 EC-SOD 的慢性缺氧小鼠以及缺乏 NADPH 氧化酶 gp91phox 亚基的小鼠来提供体内分子和药理学证据，证明细胞外 O2- 调节关键的缺氧反应基因，并有助于慢性缺氧诱导的肺血管重塑和发育中肺的肺动脉高压。为了补充这个模型，在目标3中，我们将使用从新生牛犊中分离的PA外膜成纤维细胞作为体外实验的高度相关的模型系统，以测试缺氧诱导的细胞外O2-对氧化还原敏感转录因子Egr-1表达的影响。慢性缺氧刺激肺血管重塑和肺动脉高压的研究引人注目，因为缺氧是多种肺部疾病的共同特征。因此，通过推进我们的知识库并在动物模型中测试新的治疗方法，我们将为未来一系列与缺氧性肺病相关的人体临床试验提供坚实的基础，以改善患有这些困难和严重问题的患者的健康结果。项目叙述：缺氧会使婴儿和儿童的严重肺部疾病复杂化，这些患者发生肺血管重塑和肺动脉高压，导致右心衰竭，大大增加发病率和死亡率。该提案测试了细胞外超氧化物产生和清除的不平衡是否有助于慢性缺氧性肺动脉高压的结构重塑。该提案将为未来一系列与缺氧性肺部疾病相关的人体临床试验奠定基础，以改善患有这些困难和严重问题的儿科患者的健康结果。