DNA methylation of extracellular superoxide dismutase in pulmonary hypertension

肺动脉高压细胞外超氧化物歧化酶 DNA 甲基化

• 批准号: 8335465
• 负责人: Eva S. Nozik
• 金额: $ 7.65万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-23 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8335465
• 关键词: Address; Adult; Affect; Animal Model; Antioxidants; Attenuated; Azacitidine; Biology; Blood Vessels; Bronchi; Cell Proliferation; Cells; Child; CpG Islands; Cytosine; DNA Methylation; Data; Development; Diagnosis; Disease; Disease Progression; Enzymes; Epigenetic Process; Event; Fibrosis; Foundations; Freezing; Gene Delivery; Gene Expression; Gene Proteins; Genes; Genetic Transcription; Genomics; Goals; Guanosine; Human; Human Development; Hypermethylation; Hypertension; Inflammation; Injury; Lead; Life; Lung; Lung Transplantation; Lung diseases; Measures; Mediating; Messenger RNA; Methylation; Modification; Molecular; National Heart, Lung, and Blood Institute; Normal Cell; Nucleotides; Organ Transplantation; Pathogenesis; Pathway interactions; Patients; Process; Promoter Regions; Protein Isoforms; Proteins; Pulmonary Circulation; Pulmonary Hypertension; Pulmonary artery structure; Reactive Oxygen Species; Regulation; Research; Research Personnel; Research Proposals; Role; Sampling; Serum; Smooth Muscle Myocytes; Superoxide Dismutase; Superoxides; Testing; Therapeutic; Time; Tissue Banking; Tissue Banks; Tissues; Transgenic Mice; Vascular Diseases; Vascular remodeling; Work; attenuation; base; bisulfite; cancer cell; demethylation; disorder control; enzyme activity; extracellular; human disease; improved; inhibitor/antagonist; neoplastic cell; novel; novel therapeutics; promoter; protein expression; pulmonary arterial hypertension; tool

Idiopathic pulmonary arterial hypertension (IPAH) is a life-threatening disease of the pulmonary circulation affecting children and adults. Accumulating evidence indicates that one key factor that contributes to the pathogenesis of vascular diseases, including PAH, is an increase in reactive oxygen species, such as superoxide (O2-), that exceed antioxidant capabilities. One critically important antioxidant in the vessel wall is extracellular superoxide dismutase (EC-SOD), the sole enzymatic defense against extracellular O2-. EC-SOD is the most highly expressed SOD isoform in the vasculature under normal conditions, and EC-SOD expression is decreased in animal models of lung or vascular injury and several human diseases, including one study showing a decrease in EC-SOD protein in the bronchus of 8 patients with IPAH. Augmenting EC- SOD activity in transgenic mice or through adenoviral gene delivery attenuates pulmonary vascular remodeling and pulmonary hypertension. The regulation of EC-SOD in IPAH has not been investigated. It is now recognized that gene expression can be regulated by epigenetic modifications including cytosine methylation within the promoter region, specifically cytosines adjacent to guanosine nucleotides (CpG islands). New data identify CpG islands within the EC-SOD promoter that can be methylated, and indicate that hypermethylation of the EC-SOD promoter inhibits EC-SOD transcription in human cancer cells, contributing to enhanced tumor cell proliferation. Based on these data, we hypothesize that DNA methylation of the EC-SOD promoter mediates silencing of this protective gene and contributes to the pathogenesis of idiopathic pulmonary arterial hypertension. Aim 1 will utilize lung and pulmonary artery tissue and serum procured at the time of organ transplantation in patients with IPAH, disease-specific controls with PAH due to other causes, or patients without PAH to determine whether EC-SOD gene and protein as well as enzyme activity are decreased in IPAH and test the impact of EC-SOD expression on pulmonary artery smooth muscle cell proliferation. Specific Aim 2 will then use bisulfite genomic sequencing to test whether the EC-SOD promoter in pulmonary artery tissue and pulmonary artery smooth muscle cells from humans with IPAH is hypermethylated, and if reversal of methylation restores EC-SOD expression and normal cell proliferation. The tissue and cell samples used in this study will have been procured and processed through the efforts of the investigators of the Pulmonary Hypertension Breakthrough Initiative. Our findings will serve as strong preliminary data for the subsequent submission of a comprehensive RO1 application investigating the regulation of EC-SOD in IPAH. The long term goals are to establish new pathways important in the regulation of this pivotal antioxidant enzyme in the vessel wall, identify the role of extracellular superoxide in proliferation, inflammation and fibrosis contributing to pulmonary vascular remodeling, and provide a rationale for novel therapeutic tools to improve treatment of this lethal disease affecting children and adults.

特发性肺动脉高压（IPAH）是一种威胁生命的肺循环疾病 影响儿童和成人。积累证据表明，有助于 包括PAH在内的血管疾病的发病机理是活性氧的增加，例如 超过抗氧化能力的超氧化物（O2-）。容器壁中一种至关重要的抗氧化剂是 细胞外超氧化物歧化酶（EC-SOD），唯一针对细胞外O2-的酶促防御。 EC-SOD 是在正常条件下脉管系统中表达最高的SOD同工型，EC-SOD 在肺或血管损伤的动物模型和几种人类疾病中，表达降低，包括 一项研究表明，8例IPAH患者的支气管中EC-SOD蛋白的降低。增加ec- 转基因小鼠或通过腺病毒基因递送的SOD活性减弱肺血管重塑 和肺动脉高压。尚未调查IPAH中EC-SOD的调节。现在 认识到基因表达可以通过包括胞嘧啶甲基化的表观遗传修饰来调节 在启动子区域内，特别是与鸟苷核苷酸（CPG岛）相邻的细胞氨酸。新数据 识别可以甲基化的EC-SOD启动子中的CpG岛，并表明高甲基化 EC-SOD启动子的抑制人类癌细胞中的EC-SOD转录，导致肿瘤增强 细胞增殖。基于这些数据，我们假设EC-SOD启动子的DNA甲基化 介导该保护基因的沉默，并有助于特发性肺的发病机理 动脉高血压。 AIM 1将利用肺和肺动脉组织和血清。 因其他原因引起的IPAH患者的器官移植，患有PAH的疾病特异性对照或患者 没有PAH来确定EC-SOD基因和蛋白质以及酶活性是否会降低 IPAH并测试EC-SOD表达对肺动脉平滑肌细胞增殖的影响。具体的 然后，AIM 2将使用甲硫酸硫酸基因组测序来测试肺动脉中的EC-SOD启动子是否 来自IPAH的人类的组织和肺动脉平滑肌细胞是高甲基化的，如果逆转 甲基化恢复EC-SOD表达和正常细胞增殖。在此使用的组织和细胞样品 研究将是通过肺部研究人员的努力来采购和处理的 高血压突破性倡议。我们的发现将作为随后的强大初步数据 提交一项全面的RO1申请，调查了IPAH的EC-SOD调节。长 术语目标是建立在调节这种关键抗氧化剂酶中重要的新途径 血管壁，确定细胞外超氧化物在增殖，炎症和纤维化中的作用 肺血管重塑，并为改善治疗的新型治疗工具提供了理由 影响儿童和成人的致命疾病。