Hypoxia-mediated protective estrogen receptor signaling in pulmonary hypertension

肺动脉高压中缺氧介导的保护性雌激素受体信号传导

• 批准号: 8974320
• 负责人: Tim Lahm
• 金额: --
• 依托单位: RLR VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8974320
• 关键词: Acute; Affect; Apoptosis; Attenuated; Autophagocytosis; Biochemical; Biogenesis; Biological; Blood Vessels; Cardiopulmonary; Cell Hypoxia; Cell Proliferation; Cell Wall; Chemicals; Chronic lung disease; Clinical; Complement; Data; Development; Disease; Echocardiography; Endothelium; Estradiol; Estrogen Receptors; Estrogens; Event; Exhibits; Failure; Female; Genetic Transcription; Goals; Health; Hypertrophy; Hypoxia; Hypoxia Inducible Factor; In Vitro; Investigation; Ischemia; KDR gene; Knock-out; Longevity; Lung; MAP Kinase Gene; MAPK3 gene; Measurement; Mediating; Mission; Mitochondria; Modeling; Molecular; Molecular Target; Muscle Cells; Pathway interactions; Patients; Pattern; Pulmonary Hypertension; Pulmonary artery structure; Rattus; Receptor Signaling; Research; Right ventricular structure; Rodent Model; Signal Transduction; Time; Tissues; Transgenic Mice; Transgenic Organisms; Vascular Proliferation; Vasodilation; Ventricular; Ventricular Remodeling; Veterans; Woman; Work; base; cardiopulmonary system; clinically relevant; exercise capacity; hemodynamics; hormone therapy; hypoxia inducible factor 1; improved; improved functioning; in vivo; insight; male; mitochondrial autophagy; mouse model; novel; overexpression; primary pulmonary hypertension; programs; protective effect; pulmonary artery endothelial cell; receptor expression; research study; response; simulation; therapeutic target; treatment strategy; vasoconstriction

DESCRIPTION (provided by applicant): Hypoxia-induced pulmonary hypertension (HPH) is a serious clinical problem in veterans with chronic lung disease. 17beta-estradiol (E2) attenuates HPH, but the mechanisms are poorly understood. Our preliminary data demonstrate that 1) E2's anti-proliferative effects occur exclusively during actual or chemical hypoxia and 2) hypoxia upregulates estrogen receptor (ER) transcription and/or expression in pulmonary artery endothelial cells (PAECs) and the right ventricle (RV). We hypothesize that the mechanism through which E2 attenuates PH development and improves RV function is through hypoxia- and hypoxia-inducible factor (HIF) 1alpha- enabled increases in ER expression in the PA-RV unit, with subsequent induction of cellular autophagy and improved RV mitochondrial biogenesis. Since RV failure in both HPH as well as non-hypoxic forms of PH is characterized by global or local (cellular) hypoxia with activation of known HIF-1alpha inducers, we propose that the RV-protective effects of the E2-ER-axis against hypoxia-induced (adaptive) RV remodeling will extend to RV failure characterized by maladaptive remodeling. Our mechanistic experimental approach utilizes comprehensive clinically relevant PH endpoints in vivo, complemented by studies in primary PAECs. We propose the following specific aims: SA#1: To determine if enhancing ER signaling protects against development of PH. 1a: To establish the pattern and time course of hypoxia- and HIF1¿-induced increases in ER expression in the pulmonary vasculature and RV. 1b: To investigate if transgenic conditional tissue-specific enhancement of ER signaling potentiates E2's protective effects in HPH and even in non-hypoxic forms of PH. 1c: To interrogate whether enhancing ER signaling is sufficient to protect against HPH or non-hypoxic PH even in the absence of further stimulation by exogenous E2 SA#2: To establish the mechanisms by which E2 inhibits RV remodeling and improves RV function during both adaptive and maladaptive RV responses in PH. 2a: To elucidate if E2 protects against pathological RV remodeling by a mechanism involving ER¿-dependent autophagy in both adaptive and maladaptive RV hypertrophy models. 2b: To investigate if E2 improves RV function by optimizing mitochondrial substrate utilization during both adaptive and maladaptive RV responses in PH. In vivo experiments will be performed in two distinct rodent models of PH: a) HPH and b) VEGF-receptor blockade plus hypoxia-induced PH. We will primarily employ transgenic mouse models for mechanistic experiments, and use rats for studies requiring comprehensive analysis of functional endpoints. Endpoints assessed in vivo include hemodynamics, RV form/function by echocardiography, exercise capacity, and PA/RV remodeling, complemented by in vivo and in vitro measurements of ER expression, cellular proliferation, survival, apoptosis and autophagy, as well as HIF-1alpha activation and mitochondrial substrate utilization. The proposed studies are novel because they will 1) for the first time establish the mechanisms of ER protection in the cardiopulmonary system; 2) be the first investigations to extend the protective effects of E2 to more severe forms of RV failure; and 3) substantiate the novel appreciation of the key role of autophagy and mitochondrial substrate utilization in ER-mediated protection in the failing RV. The studies proposed are significant because 1) the results will facilitate the identification of nw therapeutic targets directed at advanced forms of RV failure; 2) the work will be a critical step towards our long-term goal of developing targeted non-hormonal therapies to benefit male and female veterans with PH; and 3) the results may explain why women are more prone to idiopathic pulmonary arterial hypertension development, yet - once affected - exhibit less severe disease.

描述（由申请人提供）： 缺氧诱导的肺动脉高压（HPH）是患有慢性肺部疾病的退伍军人的严重临床问题。 17beta-雌二醇（E2）减弱了HPH，但这些机制知之甚少。我们的初步数据表明，1）E2的抗增殖作用仅发生在实际或化学缺氧期间，2）缺氧上调雌激素受体（ER）转录和/或表达肺动脉内皮细胞（PAEC）和右气流（RV）。我们假设E2通过缺氧和缺氧诱导因子（HIF）1α启用PA-RV单位的ER表达增加的机制是通过缺氧和缺氧诱导因子（HIF）提高ER的增加的机制，随后诱导了细胞自噬和改善的RV rV线粒体生物发生。由于HPH的RV失败以及pH的非催眠形式的特征在于全球或局部（细胞）缺氧，并激活已知的HIF-1Alpha影响，因此我们提出，E2-ER轴针对低氧诱导的（适应性）RV重塑的RV保护作用将扩展到RV失败的RV衰竭，从而扩展到RV衰竭的特征性重塑。我们的机械实验方法利用了体内综合临床相关的pH端点，这是由原发性PAEC的研究完成的。我们提出以下特定目标：SA＃1：确定增强ER信号是否可以防止pH的发展。 1a：建立缺氧 - 和HIF1敦诱导的肺脉管系统和RV中ER表达的增加的模式和时间过程。 1B：研究ER信号传导电位的转基因条件组织特异性增强E2在HPH乃至非催眠形式中的受保护作用。 1C：询问增强ER信号是否足以防止HPH或非催化性pH值，即使没有外源E2 SA＃2进一步刺激：建立E2在pH中的适应性和不适性RV响应过程中E2抑制RV重塑并改善RV功能的机制。 2a：阐明E2是否通过适应性和不良适应性RV肥大模型中涉及的机制依赖于ER依赖性自噬来防止病理RV重塑。 2B：研究E2是否通过在pH中的自适应和适应不良的RV响应期间优化线粒体底物利用来提高RV功能。体内实验将在PH的两个不同的啮齿动物模型中进行：a）HPH和B）VEGF-受体阻滞加上缺氧诱导的pH。我们将用于机械实验的主要员工转基因小鼠模型，并使用大鼠进行研究，需要对功能终点进行全面分析。在体内评估的终点包括血液动力学，通过超声心动图，运动能力和PA/RV重塑，由体内完成以及ER表达的体外测量，细胞增殖，生存，凋亡，凋亡和自噬，以及HIF-1Alpha-1Alpha-1Alpha活化和MITOCHRIDIADE rIDITIATION。拟议的研究是新颖的，因为它们将1）首次建立心肺系统中ER保护的机制； 2）成为将E2的保护作用扩展到更严重的RV故障的首次研究； 3）证实了对自噬和线粒体底物利用率在失败的RV中的ER介导的保护中的关键作用的新颖欣赏。提出的研究很重要，因为1）结果将有助于鉴定出针对RV衰竭高级形式的NW治疗靶标的； 2）这项工作将是我们朝着我们的长期目标迈出的关键一步，即开发有针对性的非荷尔蒙疗法以使男性和女性退伍军人受益匪浅； 3）结果可能解释了为什么女性更容易发生特发性肺动脉高压发育，但一旦受影响 - 暴露了严重的疾病。