PPAR gamma and Nox4 in pulmonary hypertension

PPAR γ 和 Nox4 在肺动脉高压中的作用

基本信息

批准号：
8963181
负责人：
C MICHAEL HART
金额：
$ 30.92万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-01-01 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8963181
关键词：
Accounting Attenuated Biogenesis Biological Assay Blood Vessels Cell Count Cell Proliferation Cells Clinical Complex Confocal Microscopy Critical Pathways Data Disease Echocardiography Fluorescence Functional disorder Funding Generations Genetic Genus Hippocampus Glycolysis Health Hormones Human Hydrogen Peroxide Hypoxia Immunohistochemistry In Vitro Knockout Mice Ligands Link Lung Measures Membrane Potentials Metabolic Mitochondria Mitogen-Activated Protein Kinase 3 Modeling Morbidity - disease rate Mus NADPH Oxidase Nuclear Nuclear Antigens Oleic Acids Oxygen Consumption PPAR gamma Pathogenesis Pathology Pathway interactions Patients Phenotype Play Predisposition Production Proliferating Proteins Pulmonary Hypertension Pulmonary Vascular Resistance Pulmonary artery structure Reactive Oxygen Species Research Research Personnel Right Ventricular Hypertrophy Role Small Interfering RNA Smooth Muscle Smooth Muscle Actin Staining Method Smooth Muscle Myocytes Staining method Stains Stimulus Systolic Pressure Techniques Testing UCP2 protein Vascular remodeling Vasodilation Ventricular Ventricular Function arteriole catalase gain of function in vivo in vivo Model insight loss of function mitochondrial dysfunction mitochondrial membrane morphometry mortality new therapeutic target novel novel strategies overexpression pulmonary arterial hypertension receptor response skills transcription factor

项目摘要

DESCRIPTION (provided by applicant): Pulmonary hypertension (PH) is a complex disorder that causes significant morbidity and mortality. Mounting evidence suggests that metabolic derangements account for the pathophysiology underlying PH. This proposal focuses peroxisome proliferator-activated receptor gamma (PPARγ), a major metabolic regulator that is decreased PH. Hypoxia and other causes of PH decrease PPARγ expression which increases NADPH oxidase 4 (Nox4) expression and activity. Nox4 generates reactive oxygen species (ROS) that contribute to pulmonary vascular cell proliferation and PH pathogenesis. On the other hand, stimulating PPARγ reduces the expression and activity of Nox4 and attenuates hypoxia-induced vascular remodeling, right ventricular hypertrophy, and PH. The mechanisms by which PPARγ modulates PH continue to be defined. Preliminary data suggest that reductions in PPARγ reduce the expression of PPARγ coactivator 1 alpha (PGC1α) and uncoupling protein 2 (UCP2), proteins that regulate mitochondrial (MT) biogenesis and reactive oxygen species (ROS) generation, respectively. The proposed studies will test the hypothesis that PPARγ depletion reduces pulmonary artery smooth muscle cell (PASMC) PGC1α and UCP2 and stimulates MT dysfunction and ROS production. The investigators further postulate that MT ROS activate the ERK 1/2-NF-κB axis to increase Nox4 expression and H2O2 generation which promote PASMC proliferation, pulmonary vascular remodeling, and PH. To test this hypothesis, Specific Aim 1 will explore the role of reduced PPARγ activity in MT dysfunction, Nox4 induction, and PASMC proliferation using complementary in vitro and in vivo models. Genetic or pharmacological reductions in PPARγ activity will be used in human PASMC in vitro, and inducible, smooth muscle-targeted PPARγ knockout mice (smPPARγKO) will be employed in vivo. Specific Aim 2 will examine the role of reductions in PPARγ in hypoxia-induced alterations in PGC1α and UCP2, MT dysfunction, Nox4 induction, and PASMC proliferation. In vitro and in vivo gain and loss of PPARγ function models will be exposed to well characterized control or hypoxic conditions, and MT function, ROS production, and PASMC proliferation will be determined. Hypoxia-induced PH will be assessed with measures of right ventricular systolic pressure, right ventricular hypertrophy, and ventricular function (echocardiography). PASMC proliferation will be examined with immunohistochemistry for proliferating cellular nuclear antigen and morphometric analysis of lung sections stained for α-smooth muscle actin. The ability of full and partial (10- nitro-oleic acid) PPARγ ligands to attenuate hypoxic proliferatin and PH will be tested. Critical observations will be confirmed in PASMC isolated from patients with idiopathic pulmonary arterial hypertension. The proposed studies, conducted by a productive and collaborative research team, will advance understanding of the role of PPARγ in regulating PASMC phenotype during health and disease and identify novel strategies by which targeting PPARγ can interrupt PH pathogenesis.

描述（由申请人提供）：肺动脉高压 (PH) 是一种复杂的疾病，导致显着的发病率和死亡率。越来越多的证据表明，代谢紊乱是 PH 的病理生理学原因。本提案重点关注过氧化物酶体增殖物激活受体 γ (PPARγ)。主要代谢调节因子是 PH 值降低缺氧和其他 PH 值降低 PPARγ 表达，从而增加 NADPH 氧化酶 4 (Nox4) 表达， Nox4 产生活性氧 (ROS)，有助于肺血管细胞增殖和 PH 发病机制；另一方面，刺激 PPARγ 的表达和 Nox4 的活性，并减弱缺氧诱导的血管重塑、右心室肥厚和 PH。 PPARγ 调节 PH 的机制仍在研究中。初步数据表明，PPARγ 的减少会降低 PPARγ 共激活剂 1 α 的表达。 (PGC1α) 和解偶联蛋白 2 (UCP2)，分别调节线粒体 (MT) 生物发生和活性氧 (ROS) 生成。拟议的研究将检验 PPARγ 消耗减少肺动脉平滑肌细胞 (PASMC) PGC1α 的假设。和 UCP2 并刺激 MT 功能障碍和 ROS 产生。研究人员进一步推测 MT ROS 激活 ERK 1/2-NF-κB 轴以增加 Nox4 表达和H2O2 的产生促进 PASMC 增殖、肺血管重塑和 PH。为了检验这一假设，特定目标 1 将探讨 PPARγ 活性降低在 MT 功能障碍、Nox4 诱导、使用互补的体外和体内模型进行 PPARγ 活性的遗传或药理学降低将用于体外人类 PASMC，而体内将采用可诱导的、平滑肌靶向的 PPARγ 敲除小鼠 (smPPARγKO)。将研究 PPARγ 减少在缺氧诱导的 PGC1α 和 UCP2 改变、MT 功能障碍、Nox4 诱导和 PASMC 增殖中的作用。 PPARγ 功能的体外和体内获得和丧失模型将暴露于特征明确的对照或缺氧条件下，并通过测量右心室收缩压来评估 MT 功能、ROS 产生和缺氧诱导的 PH。、右心室肥厚和心室功能（超声心动图）将通过免疫组织化学检查增殖细胞核抗原和肺切片的形态分析。 α-平滑肌肌动蛋白染色完整和部分（10-硝基油酸）PPARγ 配体减弱缺氧增殖和 PH 的能力将在从特发性肺动脉高压患者中分离出的 PASMC 中得到证实。拟议的研究由一个富有成效的协作研究团队进行，将加深对 PPARγ 在健康和疾病期间调节 PASMC 表型的作用的理解，并确定新的策略，通过该策略靶向PPARγ 可以中断 PH 发病机制。