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: 9280794
• 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/9280794
• 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; Pathologic; Pathway interactions; Patients; Pattern; Pharmacology; 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; cardiopulmonary system; clinically relevant; exercise capacity; experimental study; hemodynamics; hypoxia inducible factor 1; improved; improved functioning; in vivo; insight; male; mouse model; novel; overexpression; primary pulmonary hypertension; programs; protective effect; public health relevance; pulmonary artery endothelial cell; receptor expression; 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）： 缺氧引起的肺动脉高压 (HPH) 是患有慢性肺病的退伍军人的一个严重的临床问题，17β-雌二醇 (E2) 会减弱 HPH，但我们的初步数据表明，1) E2 的抗增殖作用仅发生。在实际缺氧或化学缺氧期间，2) 缺氧上调肺动脉内皮细胞 (PAEC) 中的雌激素受体 (ER) 转录和/或表达，以及我们勇敢地说，E2 减弱 PH 发展并改善 RV 功能的机制是通过缺氧和缺氧诱导因子 (HIF) 1α 使 PA-RV 单元中 ER 表达增加，随后诱导细胞自噬和改善 RV 线粒体生物合成 由于 HPH 和非缺氧形式的 PH 中 RV 衰竭的特征是全局或局部（细胞）缺氧并伴有已知的激活。 HIF-1α 诱导剂，我们认为 E2-ER 轴对缺氧诱导的（适应性）RV 重塑的 RV 保护作用将扩展到以适应不良重塑为特征的 RV 衰竭。我们的机制实验方法利用了全面的临床相关 PH 终点。体内，辅之以原发性 PAEC 的研究，我们提出以下具体目标：SA#1：确定增强 ER 信号传导是否可以防止 PH 的发展：建立模式。缺氧和 HIF1 诱导的肺血管和 RV 中 ER 表达增加的时间过程 1b：研究 ER 信号传导的转基因条件组织特异性增强是否会增强 E2 在 HPH 甚至非缺氧形式中的保护作用。 PH.1c：询问即使在没有外源性 E2 进一步刺激的情况下，增强 ER 信号传导是否足以预防 HPH 或非缺氧性 PH。 SA#2：建立 E2 在 PH 的适应性和适应不良 RV 反应期间抑制 RV 重塑并改善 RV 功能的机制 2a：阐明 E2 是否通过涉及 ERβ 依赖性自噬的机制来防止病理性 RV 重塑。适应性和适应不良 RV 肥大模型：研究 E2 是否通过优化 PH 中适应性和适应不良 RV 反应期间的线粒体底物利用率来改善 RV 功能。体内实验将在两种不同的 PH 啮齿动物模型中进行：a) HPH 和 b) VEGF 受体阻断加缺氧诱导的 PH。我们将主要采用转基因小鼠模型进行机制实验，并使用大鼠进行需要全面分析功能的研究。体内评估的终点包括血流动力学、超声心动图的 RV 形式/功能、运动能力和 PA/RV 重塑，并辅以 ER 表达、细胞增殖、存活的体内和体外测量。细胞凋亡和自噬，以及 HIF-1α 激活和线粒体底物利用是新颖的，因为它们将 1) 首次建立心肺系统中 ER 保护的机制；2) 成为第一个扩展 ER 保护机制的研究。 E2 对更严重形式的 RV 衰竭的保护作用；3) 证实了自噬和线粒体底物利用在 ER 介导的 RV 衰竭保护中的关键作用的新认识。 1) 结果将有助于确定针对晚期 RV 衰竭的新治疗靶点；2) 这项工作将是实现我们开发有针对性的非激素疗法以造福患有 PH 的男性和女性退伍军人的长期目标的关键一步； ；3）结果可以解释为什么女性更容易患特发性肺动脉高压，但一旦受到影响，病情却不太严重。