Estrogen/GPR30 Modulation of Cardiac RAS Metabolism in Sex-Specific Hypertensive

项目3 -项目概要/摘要 高血压和左心室舒张功能障碍（LVDD）先于女性心力衰竭（HF）， 特别是在卵巢雌激素丧失的情况下（例如，绝经或卵巢早衰）。有 没有经过证实的药物干预可以延迟或逆转LVDD或随后的舒张期HF。肾素- 血管紧张素系统（RAS）在高血压性心脏病的病理生理学中起着关键作用， 提示ACE抑制剂在接受高血压治疗女性中的效果可能不如男性， HF。发现糜酶可以直接从Ang-（1-12）形成Ang II，而不依赖于ACE， 为女性LVDD发病机制的研究开辟了新的方向。我们发现， 新型雌激素受体GPR 30通过其激动剂G1减轻了雌激素损失对 心脏LVDD表型和心脏糜蛋白酶表达减少，提示机制联系 GPR 30和本地RAS之间的连接。我们的长期目标是了解糜酶/RAS的变化是如何影响 雌激素损失后的代谢触发导致纤维化和LVDD的适应不良途径。的目标 本项目旨在确定E2/GPR 30限制肥大细胞糜酶作用的机制， 心肌细胞中由Ang-（1-12）形成的细胞内Ang II。我们假设表达和 在雌激素紊乱的高血压动物的心脏中，糜酶和Ang-（1-12）的功能更高 活性，并且这些作用可以通过雌激素（E2）替代和GPR 30活化来逆转。 在强有力的初步数据的指导下，我们将在三个目标中测试我们的假设：1）描述 自分泌/旁分泌酶途径导致心脏Ang II形成、LVDD和 2）确定E2是否激活GPR 30，而不是激活经典的雌激素 受体ER β和ER β，限制心脏糜酶/Ang-（1-12）代谢，以保护LV结构， 功能;和3）鉴定负调节糜酶产生/释放的E2/GPR 30特异性机制 肥大细胞和糜酶介导的心肌细胞中Ang-（1-12）代谢/Ang II产生。我们 创新的全球系统生物学方法集成了（a）生理、生化、细胞和 分子方法学;（B）转基因啮齿动物和鼠模型;（c）培养的肥大细胞和 心肌细胞;（d）GPR 30-、ER β-和ER β-基因沉默的体外细胞。证实了我们的假设 将显著推进我们对肥大细胞糜酶、Ang-（1-12）和Ang II表达 E2通过GPR 30调节RAS的表达和功能，并提供了一种机制，解释了RAS抑制剂 在雌激素治疗后的女性中， 损失

Project 3 - Project Summary / Abstract Hypertension and left ventricular diastolic dysfunction (LVDD) precede heart failure (HF) in women, particularly with the loss of ovarian estrogens (e.g., with menopause or premature ovarian failure). There are no proven pharmacologic interventions that delay or reverse LVDD or subsequent diastolic HF. The renin- angiotensin system (RAS) plays a key role in the pathophysiology of hypertensive heart disease, but trials suggest ACE inhibitors may be less effective in women than men receiving treatment for hypertension and HF. The discovery that chymase can form Ang II directly from Ang-(1-12), independent of ACE, has opened up a new direction in research on the pathogenesis of LVDD in women. We showed that chronic activation of the novel estrogen receptor GPR30 by its agonist G1 mitigated the adverse effects of estrogen loss on the cardiac LVDD phenotype and reduced expression of cardiac chymase, suggesting a mechanistic link between GPR30 and the local RAS. Our long-term goal is to understand how changes in chymase/RAS metabolism after estrogen loss triggers maladaptive pathways leading to fibrosis and LVDD. The objective of this project is to determine the mechanism by which E2/GPR30 limits the action of mast cell chymase on intracellular Ang II formation from Ang-(1-12) in cardiomyocytes. We hypothesize that expression and function of chymase and Ang-(1-12) are higher in the hearts of hypertensive animals with disrupted estrogen activity, and that these effects can be reversed with estrogen (E2) replacement and GPR30 activation. Guided by strong preliminary data, we will test our hypothesis in three aims: 1) Characterize the autocrine/paracrine enzymatic pathway leading to cardiac Ang II formation, LVDD, and remodeling after estrogen loss; 2) Determine if E2 activation of GPR30, as opposed to activation of the classic estrogen receptors ER� and ER�, limits cardiac chymase/Ang-(1-12) metabolism to preserve LV structure and function; and 3) Identify E2/GPR30-specific mechanisms that negatively regulate chymase production/release from mast cells and chymase-mediated Ang-(1-12) metabolism/Ang II production in cardiomyocytes. Our innovative global systems biology approach integrates the use of (a) physiological, biochemical, cellular, and molecular methodologies; (b) transgenic rodent and murine models; (c) cultured mast cells and cardiomyocytes; and (d) GPR30-, ER�-, and ER�-gene silenced cells in vitro. Confirmation of our hypothesis will significantly advance our understanding of how mast cell chymase, Ang-(1-12), and Ang II expression and function may be regulated by E2 via GPR30, and provide a mechanism that explains why RAS inhibitors are less effective in blocking Ang II-mediated adverse cardiac remodeling and LVDD in women after estrogen loss.