Mechanisms of Prostacyclin signaling in Pulmonary Arterial Hypertension

肺动脉高压中前列环素信号传导机制

• 批准号: 7662797
• 负责人: MARK W GERACI
• 金额: $ 22.57万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7662797
• 关键词: Accounting; Affect; Biological Models; Blood Vessels; Cells; Chromosomal Loss; CpG Islands; Data; Development; Disease; Down-Regulation; Effectiveness; Endothelial Cells; Endothelin; Enzymes; Epigenetic Process; Epoprostenol; Epoprostenol Receptors; Fluorescent in Situ Hybridization; Frequencies; Gene Expression; Genes; Genetic; Genetic Polymorphism; Haplotypes; Human; Hypertrophy; Hypoxia; Instruction; Length; Lesion; Loss of Heterozygosity; Lung; Mediating; Membrane; Methylation; Minisatellite Repeats; Modeling; Morbidity - disease rate; Mus; Nuclear; Nuclear Receptors; Onset of illness; Outcome; Pathology; Pathway interactions; Patients; Peroxisome Proliferator-Activated Receptors; Persons; Population; Predisposition; Promoter Regions; Prostacyclin synthase; Prostaglandins I; Publishing; Pulmonary Hypertension; Pulmonary artery structure; Relative (related person); Role; Severities; Severity of illness; Signal Transduction; Single Nucleotide Polymorphism; Smooth Muscle; Transactivation; Transgenic Mice; Translating; Variant; Vascular remodeling; Work; analog; cell growth; cell type; disorder prevention; human disease; hypertension treatment; improved; inhibitor/antagonist; mouse model; novel; phosphodiesterase V; pre-clinical; pressure; primary pulmonary hypertension; progesterone 11-hemisuccinate-(2-iodohistamine); promoter; pulmonary arterial hypertension; receptor

Pulmonary Arterial Hypertension (PAH) is characterized by elevations in pulmonary artery pressure,vascular remodeling, and hyperproliferation of endothelial cells. While there is no cure or prevention for this disease, newer targetedtherapies can improve outcomes by altering vascular tone using prostacyclin (PGI2) analogues, dual endothelin antagonists, or phosphodiesterase - 5 inhibitors. Recent progress inthe understanding of genetic aberrations in PAH suggests that modifier genes are potentially involved in mediating increased susceptibility and severity. Two genes that affect the level of prostacyclin signaling, prostacyclin synthase (PGIS) and the nuclear receptor PPARy, are down-regulated in patients with PAH. Disruption of PGI2 signaling through the PPARy pathway leads to aberrant cell growth. Our hypothesis proposes that PGI2 can signal through either PGIR or PPARy. We hypothesize that signaling through PGIR results in more prominent effects on vascular tone while PPARy stimulation results in effects onvascular remodeling. This proposal focuses on 1) the effectiveness of augmenting signaling through the two different PGI2 receptors as a treatment to reverse remodeling of both smooth muscle and endothelial cells in PAH (PPARY) or vascular tone (PGIR), 2) the potential modifier gene role of the PGIS and gene in conferring a predisposition to PAH and an increased likelihood of developing severe PAH,and 3) the mechanism of PGIS and PPARy loss of expression in human disease. We will use two sophisticated murine modeling systems generated by our group to dissect the relative contribution of the two receptors to the development of PAH. Our preliminary work demonstrates that sequence variation in the proximal PGIS promoter region affects promoter activity leading to low PGIS expression. We will sequence the PGIS promoters from familial pulmonary hypertension, correlating specific haplotypes with disease on-set, severity, and morbidity. Finally, because epigenetic silencing and chromosomal loss are common mechanisms of gene expression down- regulation, we will determine if either is responsible for PGIS or PPARy down-regulation in micro-dissected PAH lesions using methylation specific PCR (MSP) and fluorescence in situ hybridization (FISH). Specific Aim 1: Delineate the contributions of PGIS and PPARy pathwaysto PAH susceptibility and severity. Specific Aim 2: Define transcriptional activity of PGIS promoter sequence variations in relevant primary cells types, and their frequency and correlation in a defined human population. Specific Aim 3: Determine if methylation silencing and/or allelic loss account for PGIS and PPARy down-regulation. RELEVANCE (See instructions): We have previously demonstrated that two critical modulators of vascular tone and proliferation (PGI2 and PPAR-/) are downregulated in disease. This application utilizes translational murine modeling to examine mechanisms of signaling important to vasculartone and remodeling. Furthermore, studies of patients with the PAH will be performed to examine the relationship of genetic polymorphisms and disease severity, as well as mechanisms of loss of PGI2 and PPARy.

肺动脉高压（PAH）的特征是肺动脉压力，血管升高 重塑和内皮细胞的过度增殖。虽然无法治愈或预防这种疾病，但 较新的针对性治疗可以通过使用前列环蛋白（PGI2）改变血管张力来改善预后 类似物，双内皮素拮抗剂或磷酸二酯酶-5个抑制剂。最近的进步 对PAH中遗传像差的了解表明，修饰基因可能参与 调解易感性和严重程度的增加。影响前列环蛋白信号水平的两个基因， Prostacyclin合酶（PGI）和核受体PARPARY在PAH患者中被下调。 PGI2信号通过PPARY途径的破坏会导致异常的细胞生长。我们的假设 提出PGI2可以通过PGIR或PPARY发出信号。我们假设通过PGIR发出信号 导致对血管张力的更突出的影响，而PPARY刺激会导致血管作用 重塑。该提案重点是1）通过两个不同的增强信号传导的有效性 PGI2受体作为一种处理PAH中平滑肌和内皮细胞的重塑的治疗方法 （PPARY）或血管张力（PGIR），2）PGI和基因在授予A的潜在修饰符基因作用 PAH的易感性和发生严重PAH的可能性增加，3）PGIS机制 人类疾病中表达的损失。我们将使用两个复杂的鼠建模系统 我们小组生成的旨在剖析两个受体对PAH发育的相对贡献。 我们的初步工作表明，近端PGIS启动子区域的序列变化会影响 启动子活性导致PGIS低表达。我们将对来自家族的PGIS启动子进行测序 肺动脉高压，将特定的单倍型与疾病的现场，严重程度和发病率相关。最后， 因为表观遗传沉默和染色体丧失是基因表达下降的常见机制 调节，我们将确定在微观驱逐的 使用甲基化特异性PCR（MSP）和荧光原位杂交（FISH）的PAH病变。具体的 AIM 1：描述PGI和PPARY PATHWAYWAWAYSTO PAH敏感性和严重性的贡献。具体的 AIM 2：定义PGIS启动子序列变化的转录活性，相关原代细胞类型， 及其在定义的人口中的频率和相关性。具体目标3：确定甲基化是否 PGI和PPARY下调的沉默和/或等位基因损失。 相关性（请参阅说明）： 我们以前已经证明了两个重要的血管张力和增殖的关键调节剂（PGI2和 PPAR-/）在疾病中被下调。该应用程序利用翻译鼠建模来检查 信号的机制对Vasculartone和重塑很重要。此外，对患者的研究 将进行PAH以检查遗传多态性和疾病严重程度的关系，如 以及PGI2和PPARY丢失的机制。