Role of microRNA-17-92 and PDLIM5 Signaling in Pulmonary Arterial Hypertension

microRNA-17-92 和 PDLIM5 信号传导在肺动脉高压中的作用

• 批准号: 8964376
• 负责人: J. Usha RAJ
• 金额: $ 39.95万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-15 至 2019-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8964376
• 关键词: Accounting; Arteries; Attenuated; Blood; Blood Vessels; Cells; Chronic; Chronic Phase; Clinical; Complex; Development; Disease; Down-Regulation; E2F1 gene; Event; Experimental Models; Failure; Functional disorder; Gene Proteins; Genes; Heart; Human; Hypoxia; Hypoxia Inducible Factor; Hypoxia-Inducible Factor Pathway; In Vitro; Knock-out; Knockout Mice; LIM Domain; Lead; Lung; MicroRNAs; Molecular; Mus; Nature; Oxygen measurement, partial pressure, arterial; Pathogenesis; Pathway interactions; Patients; Phase; Phenotype; Play; Procollagen-Proline Dioxygenase; Proteins; Public Health; Pulmonary Hypertension; Pulmonary Vascular Resistance; Pulmonary artery structure; RNA; Regulation; Reporting; Research; Resistance; Role; Severities; Side; Signal Transduction; Smooth Muscle Myocytes; Staging; Structure; Testing; Transforming Growth Factor beta; Untranslated RNA; Up-Regulation; Vascular remodeling; Ventricular; arterial remodeling; design; in vivo; inhibitor/antagonist; insight; mouse model; novel; novel strategies; overexpression; pressure; prevent; public health relevance; pulmonary arterial hypertension; reconstitution; response

 DESCRIPTION (provided by applicant): MicroRNAs (miRNAs) are small non-coding endogenous RNA molecules that are thought to be involved in the pathogenesis of pulmonary arterial hypertension (PAH) though their exact roles are not known. We found that smooth muscle cell (SMC)-specific knockout of miR-17~92 in mice attenuated hypoxia-induced pulmonary hypertension (PH) and reconstitution of miR-17~92 restored it, indicating an important role for miR-17~92 in pathogenesis of PH. We identified that miR-17~92 directly targets prolyl hydroxylase 2 (PHD2) and PDZ and LIM domain 5 (PDLIM5) proteins. Suppression of miR-17~92 induced PHD2 expression and inhibited HIF activity, induced PDLIM5 expression and decreased TGF-ß/Smad signaling and expression of SMC markers, all of which attenuated PH. SMC-specific knockout of PHD2 and PDLIM5 enhanced hypoxia-induced pulmonary artery remodeling whereas overexpression of PDLIM5 inhibited hypoxia-induced PH. These results indicate that miR-17~92 modulates PH by regulating the expression of PHD2 and PDLIM5. In PASMC in-vitro and mouse lungs in-vivo, chronic hypoxia resulted in a biphasic expression of miR-17~92: an early increase followed by a decrease in expression. We found that miR-17~92 expression was reduced in PASMC isolated from PAH patients and that this reduction in miR-17~92 accounted for the de-differentiated phenotype of the IPAH-PASMC. We speculate that up regulation of miR-17~92 may be a common initial event in the pathogenesis of both human and experimental PH and that the late decrease in miR-17~92 expression may be an adaptive mechanism to inhibit further progression of PH. Our hypothesis is that miR-17~92 initiates the pathogenesis of PAH by: 1) directly suppressing PHD2 to activate the HIF pathway; 2) directly suppressing PDLIM5 to activate the TGF-ß/Smad2/3 pathway. The biphasic nature of miR-17~92 expression in chronic hypoxia is a novel finding and we will investigate its significance and the mechanisms involved. In Specific Aim 1, we will determine the molecular mechanisms by which miR-17~92 and PHD2 regulate hypoxia- induced PH. We will investigate whether PHD2 is a novel direct target of miR-17~92 and the molecular mechanisms by which miR-17~92 and PHD2 regulate HIF activity and PH. Specific Aim 2 is to determine the molecular mechanisms by which miR-17~92 and PDLIM5 regulate hypoxia-induced vascular remodeling and PH. We will investigate whether PDLIM5 is a novel direct target of miR-17~92 and the molecular mechanisms by which PDLIM5 negatively regulates TGF-ß/Smad signaling and inhibits the progression of PH. In Specific Aim 3, we will determine the molecular mechanisms underlining the biphasic expression of miR-17~92 and its implication in PH progression. We will investigate the roles of HIF and E2F1 in up regulation of miR-17~92 in the early phase of chronic hypoxia, the role of p53 in inhibition of miR-17~92 in the late phase of chronic hypoxia, and whether knockout of miR-17~92, PHD2, and PDLIM5 in the late stage of hypoxia diminishes or accentuates PH in mice.

 描述（由申请人提供）：MicroRNA (miRNA) 是小的非编码内源性 RNA 分子，尽管其确切作用尚不清楚，但被认为参与肺动脉高压 (PAH) 的发病机制。我们发现，平滑肌细胞（SMC）特异性敲除小鼠中的 miR-17~92 可减轻缺氧诱导的肺动脉高压（PH），而重建 miR-17~92 可恢复其状态，表明 miR-17~92 在 PH 发病机制中发挥重要作用。我们发现 miR-17~92 直接靶向脯氨酰羟化酶 2 (PHD2) 以及 PDZ 和 LIM 结构域 5 (PDLIM5) 蛋白。抑制 miR-17~92 可诱导 PHD2 表达并抑制 HIF 活性，诱导 PDLIM5 表达并降低 TGF-β/Smad 信号传导和 SMC 标记物的表达，所有这些都会减弱 PH。 SMC 特异性敲除 PHD2 和 PDLIM5 增强缺氧诱导的肺动脉重塑，而 PDLIM5 过表达则抑制缺氧诱导的 PH。这些结果表明miR-17~92通过调节PHD2和PDLIM5的表达来调节PH。在体外 PASMC 和体内小鼠肺中，慢性缺氧导致 miR-17~92 的双相表达：表达早期增加，随后表达减少。我们发现从 PAH 患者分离的 PASMC 中 miR-17~92 表达降低，并且 miR-17~92 的降低解释了 IPAH-PASMC 的去分化表型。我们推测 miR-17~92 的上调可能是人类和实验性 PH 发病机制中常见的初始事件，而 miR-17~92 表达的后期下降可能是抑制 PH 进一步进展的适应性机制。我们的假设是miR-17~92通过以下方式启动PAH的发病机制：1）直接抑制PHD2以激活HIF通路； 2) 直接抑制PDLIM5以激活TGF-ß/Smad2/3途径。慢性缺氧中 miR-17~92 表达的双相性质是一个新发现，我们将研究其意义和所涉及的机制。在具体目标1中，我们将确定miR-17~92和PHD2调节缺氧诱导的PH的分子机制。我们将研究PHD2是否是miR-17~92的新的直接靶点以及miR-17~92和PHD2调节HIF活性和PH的分子机制。具体目标2是确定miR-17~92和PDLIM5调节缺氧诱导的血管重塑和PH的分子机制。我们将研究 PDLIM5 是否是 miR-17~92 的新直接靶标，以及 PDLIM5 负向调节 TGF-ß/Smad 信号传导并抑制 PH 进展的分子机制。在具体目标 3 中，我们将确定 miR-17~92 双相表达的分子机制及其在 PH 进展中的意义。我们将研究HIF和E2F1在慢性缺氧早期上调miR-17~92中的作用，p53在慢性缺氧后期抑制miR-17~92中的作用，以及在缺氧后期敲除miR-17~92、PHD2和PDLIM5是否会降低或加重小鼠的PH。