Role of miR193 in oxidized lipid induced pulmonary hypertension

 描述（由申请人提供）：肺动脉高压（PAH）是一种不可治愈的慢性肺部疾病，其特征为肺动脉压进行性升高，导致右心室（RV）心力衰竭。PAH与炎症和肺动脉平滑肌细胞和内皮细胞过度增殖相关，导致严重的肺血管重塑。有趣的是，与其他炎性疾病如动脉粥样硬化一样，已经发现氧化脂肪酸如羟基二十碳四烯酸（HETE）和羟基十八碳二烯酸（HODE）的水平在PAH患者的肺中以及在患有肺动脉高压（PH）的缺氧大鼠中上调。我们最近发现，在PAH患者和PH大鼠的血浆中，HETE和HODE的水平也显著升高。我们还发现，miR 193，一种靶向参与氧化脂肪酸产生的脂氧合酶（LOX）的miRNA，在PAH患者的肺和血浆中以及在PH的两种实验动物模型中显著下调。在大鼠和小鼠中挽救了预先存在的PH，突出了miR 193在逆转肺血管重塑中的治疗作用。为了进一步研究氧化脂肪酸在PH发展中的作用，我们将野生型小鼠置于15-HETE饮食中3周，我们发现含有15- HETE足以触发PH。我们假设HETE和HODE可能在PH中起因果作用。我们对15-HETE饮食小鼠肺的初步结果还显示：i）miR 193水平显著降低; ii）ED 1阳性炎性巨噬细胞/单核细胞增加;和iii）作为miR 193的靶标的白细胞介素-17受体D（IL 17-RD）的表达显著增加。这项建议有三个方面：i）机械臂，用于测试单独的15 HETE饮食足以通过转录因子RXR-a调节miR 193及其靶标而在WT小鼠中诱导PH的假设;和iii）治疗组，以检查miR 193在PAH患者中逆转不良血管重塑的作用。目的1将确定RXRα/miR 193/LOX通路在15-HETE饮食诱导的PH发生中的作用;目的2将确定miR 193靶向IL-17 RD和IGFR 1在15-HETE饮食诱导的PH发生中的作用;目的3将检查氧化脂肪酸和miR 193在PAH患者中的临床相关性。该提案将首次提供关于促炎氧化脂肪酸和miR 193作用的关键信息， 在肺动脉高压的调节和发展中调节其水平。

 DESCRIPTION (provided by applicant): Pulmonary arterial hypertension (PAH) is a non-curable chronic lung disease characterized by progressive increase in pulmonary arterial pressure leading to right ventricular (RV) heart failure. PAH is associated with inflammation and excessive proliferation of pulmonary artery smooth muscle cells and endothelial cells leading to severe pulmonary vascular remodeling. Interestingly, like in other inflammatory diseases such as atherosclerosis, it has been found that the levels of oxidized fatty acids such as hydroxyeicosatetraenoic acids (HETEs) and hydroxyoctadecadienoic acids (HODEs) are upregulated in the lungs from patients with PAH as well as in hypoxic rats with pulmonary hypertension (PH). We recently discovered that the levels of HETEs and HODEs are also robustly elevated in the plasma of PAH patients and in rats with PH. We also discovered that miR193, a miRNA which targets lipoxygenase (LOX) enzymes involved in the production of oxidized fatty acids, is significantly downregulated in the lungs and plasma of PAH patients and in two experimental animal models of PH. Overexpression of miR193 in the lungs rescued pre-existing PH in rats and mice highlighting the therapeutic role of miR193 in reversing pulmonary vascular remodeling. To further examine the role of oxidized fatty acids in development of PH, we placed wild type mice on 15-HETE diet for 3 weeks and we found that 15- HETE containing is sufficient to trigger PH. We hypothesize that HETEs and HODEs may play a causal role in PH. Our preliminary results in the lungs of mice on 15-HETE diet also show: i) levels of miR193 were significantly reduced; ii) ED1-positive inflammatory macrophage/monocytes were increased; and iii) expression of interlukin-17 receptor D (IL17-RD), which is a target of miR193, is significantly increased. This proposal has three arms: i) Mechanistic arm to test the hypothesis that 15HETE diet alone is sufficient to induce PH in WT mice by regulating miR193 and its targets through transcription factor RXR-a; ii) Diagnostic arm to determine whether plasma oxidized fatty acids together with miR193 could serve as biomarker panel for PAH; and iii) Therapeutic arm to examine the role of miR193 for reversal of adverse vascular remodeling in PAH patients. Aim 1 will determine the role of RXRα/miR193/LOX pathway in development of PH induced by 15-HETE diet; Aim 2 will determine the role of miR193 targets IL-17RD and IGFR1 in development of PH induced by 15-HETE diet; and Aim 3 will examine the clinical relevance of oxidized fatty acids and miR193 in PAH patients. This proposal will provide for the first time pivotal information on the role of pro-inflammatory oxidized fatty acids and miR193 that modulate their levels in the regulation and development of pulmonary hypertension.