Interplay Between Estrogen, GPR30 and Chymase/RAS in Diastolic Function

描述(由申请人提供)：绝经后女性中左室舒张功能不全(LVDD)的发生率较高，这表明与雌激素丢失有关。由于绝经后LVDD可能进展为舒张性心力衰竭，因此需要一种既能带来雌激素替代治疗的心血管益处又不会产生不良影响的治疗方法。我们的长期目标是更好地了解一种新的雌激素受体GPR30在维持女性心脏结构和功能中的作用，以及雌激素丢失后和衰老过程中心脏重构和LVDD的机制。这项应用的目的是揭示GPR30信号的心脏保护作用以及与局部肾素-血管紧张素系统(RAS)的相互作用，以及这种相互作用如何影响绝经后妇女LVDD的进展。具体地说，我们将使用心脏老化的雌激素敏感动物模型，确定GPR30与糜酶介导的血管紧张素II(Ang II)形成的细胞内关系，以及导致纤维化和促心脏功能障碍的适应不良途径。我们的中心假设是，GPR30的激活通过抑制细胞内的Chymase/Ang II，从而有利于调节心肌成纤维细胞和心肌细胞的结构和功能，从而保护心肌细胞外基质。 左心室顺应性和舒张期功能。在强大的初步数据的指导下，我们将通过追求三个特定目标来验证我们的假设：1)表征GPR30对糜酶介导的Ang II表达的抑制作用及其在衰老和雌激素丢失过程中导致大鼠和小鼠左室重构和左室肥厚的不良作用；2)确定GPR30抑制糜酶/RAS失活在减轻心肌纤维化中的分子机制和作用；3)确定GPR30对左室肌细胞震荡和抗肥厚重构的内在调节及其与细胞内糜酶/RAS的相互作用。为了实现这些目标，我们将使用全球系统生物学方法，其中包括：(A)生理、细胞和分子方法；(B)正常女性心血管衰老和与年龄相关的心脏GPR30失活的啮齿动物模型；以及(C)培养的心脏成纤维细胞和来自老化心脏的心肌细胞，无论是否有GPR30基因或糜酶基因沉默。我们的创新方法将整合来自生物体水平(整个动物/整个心脏)和单细胞水平的信息，以产生有价值的翻译数据，更准确地描述GPR30/Chymase/RAS途径在心脏生理学和LVDD中的功能。这项拟议的研究具有重要意义，因为我们的假设的证实将促进人们对雌激素如何保护绝经前心脏免受心脏病影响的理解，并为未来的临床研究提供动力，这些临床研究的重点是GPR30激活和/或糜酶抑制在预防和治疗老年妇女LVDD及其进展为心力衰竭方面的疗效。

DESCRIPTION (provided by applicant): The higher prevalence of left ventricular diastolic dysfunction (LVDD) in postmenopausal women suggests a link with estrogen loss. Because LVDD may progress to diastolic heart failure after menopause, there is a significant need for therapies that confer the cardiovascular benefits of estrogen replacement therapy without its adverse effects. Our long-term goal is to better understand the role of a new estrogen receptor, GPR30, in the maintenance of cardiac structure and function in the female heart, and the mechanisms underlying cardiac remodeling and LVDD after estrogen loss and during aging. The objective of this application is to reveal the cardioprotective role of GPR30 signaling and interactions with the local renin-angiotensin system (RAS) and how this interaction affects the progression of LVDD in post-menopausal women. Specifically, we will determine the intracellular relationships between GPR30 and chymase-mediated angiotensin II (Ang II) formation and the maladaptive pathways that lead to fibrosis and lusitropic dysfunction, using estrogen-sensitive animal models of cardiac aging. Our central hypothesis is that GPR30 activation favorably regulates the structure and function of cardiofibroblasts and cardiomyocytes by inhibiting intracellular chymase/Ang II, thereby preserving the myocardial extracellular matrix, LV compliance, and diastolic function. Guided by strong preliminary data, we will test our hypothesis by pursuing three specific aims: 1) Characterize the inhibitory role of GPR30 on chymase-mediated Ang II expression and its adverse actions that lead to LV remodeling and LVDD during aging and estrogen loss in rats and mice; 2) Define the molecular mechanisms and roles of chymase/RAS deactivation in the attenuation of cardiac fibrosis by GPR30; and 3) Determine the intrinsic regulation of LV myocyte lusitropy and anti-hypertrophic remodeling by GPR30 and its interplay with intracellular chymase/RAS. To achieve these aims, we will use a global systems biology approach that integrates (a) physiological, cellular, and molecular methodologies; (b) rodent models of normal female cardiovascular aging and age-related cardiac GPR30 deactivation; and (c) cultured cardiofibroblasts and cardiomyocytes derived from the aging heart with or without GPR30 gene or chymase gene silencing. Our innovative approach will integrate information from both the organismal level (whole animal/whole heart) and the single-cell level to generate valuable translational data that more accurately describes GPR30/chymase/RAS pathway function in cardiac physiology and LVDD. The proposed research is significant because confirmation of our hypothesis will advance understanding of how estrogen protects the premenopausal heart from cardiac disease, and provide the impetus for future clinical studies focused on the efficacy of GPR30 activation and/or chymase inhibition in the prevention and treatment of LVDD, and its progression to heart failure, in aging women.