17beta-estradiol antagonizes cardiomyocyte hypertrophy by autocrine/paracrine stimulation of a guanylyl cyclase A receptor-cyclic guanosine monophosphate-dependent protein kinase pathway

The Relationship Between Myocardial Infarction and Estrogen Use: A Literature Review

This thorough literature evaluation was prompted by significant research into the complex interactions between estrogen use and myocardial infarction (MI). Estrogen has fascinated researchers because of its possible cardioprotective benefits and its impact on cardiovascular health. In order to clarify the connection between estrogen use and the risk of MI, this review critically examines the body of prior evidence. This review focuses on estrogen and its pivotal role in cardiovascular health, concentrating on lipid metabolism, vasodilation, inflammation, and endothelial function. It examines contentious data about estrogen therapy's heart-protective effects, taking into account age, initiation timing, dosage, and dosage of administration. Genetic and epigenetic influences on MI risk among estrogen users highlight intricate, personalized estrogen effects. The conclusion summarizes the main findings and emphasizes the need for an all-encompassing strategy for initiating and managing estrogen medication. It is crucial to consider patient-specific traits and risk factors to successfully customize treatment regimens. This review sheds vital light on the potential directions for better cardiovascular treatment for postmenopausal women by shedding light on the complex link between estrogen use and myocardial infarction. The review also identifies research gaps and future objectives in this area, highlighting the demand for novel medicines and individualized strategies to improve cardiovascular outcomes.

Unraveling female reproductive senescence to enhance healthy longevity

In a society where women often want successful careers and equal opportunities to men, the early nature of ovarian aging often forces women to make difficult life choices between career and family development. Fertility in women begins to decline after the age of 37 years and it is rare for pregnancies to occur after 45. This reproductive decline in women is inevitable and culminates in menopause, which is a major driver of age-related diseases. In a world where biomedical advances are leading to modifiable biological outcomes, it is time to focus on mitigating female reproductive senescence to maintain fertility and preserve age-related hormonal functions, with the goal of providing increased life choices and enhancing healthspan. To date, reproductive longevity research remains an understudied field. More needs to be done to unravel the biology of the ovarian follicles, which are the functional units of reproductive lifespan and are comprised of cell types including the oocyte (female gamete) and a group of specialized supporting somatic cells. Biological attempts to maintain the quality and quantity of follicles in animal models through manipulating pathways involved in aging can potentially prolong female reproductive lifespan and healthspan. Here, we summarize the molecular events driving ovarian aging and menopause and the interventional strategies to offset these events. Developing solutions to female reproductive senescence will open doors to discover ways to enhance true healthy longevity for both men and women.

Sex Differences in Molecular Mechanisms of Cardiovascular Aging

Cardiovascular disease (CVD) is still the leading cause of illness and death in the Western world. Cardiovascular aging is a progressive modification occurring in cardiac and vascular morphology and physiology where increased endothelial dysfunction and arterial stiffness are observed, generally accompanied by increased systolic blood pressure and augmented pulse pressure. The effects of biological sex on cardiovascular pathophysiology have long been known. The incidence of hypertension is higher in men, and it increases in postmenopausal women. Premenopausal women are protected from CVD compared with age-matched men and this protective effect is lost with menopause, suggesting that sex-hormones influence blood pressure regulation. In parallel, the heart progressively remodels over the course of life and the pattern of cardiac remodeling also differs between the sexes. Lower autonomic tone, reduced baroreceptor response, and greater vascular function are observed in premenopausal women than men of similar age. However, postmenopausal women have stiffer arteries than their male counterparts. The biological mechanisms responsible for sex-related differences observed in cardiovascular aging are being unraveled over the last several decades. This review focuses on molecular mechanisms underlying the sex-differences of CVD in aging.

Guanylyl cyclase-A phosphorylation decreases cardiac hypertrophy and improves systolic function in male, but not female, mice

Atrial natriuretic peptide (NP) and BNP increase cGMP, which reduces blood pressure and cardiac hypertrophy by activating guanylyl cyclase (GC)-A, also known as NPR-A or Npr1. Although GC-A is highly phosphorylated, and dephosphorylation inactivates the enzyme, the significance of GC-A phosphorylation to heart structure and function remains unknown. To identify in vivo processes that are regulated by GC-A phosphorylation, we substituted glutamates for known phosphorylation sites to make GC-A^8E/8E mice that express an enzyme that cannot be inactivated by dephosphorylation. GC-A activity, but not protein, was increased in heart and kidney membranes from GC-A^8E/8E mice. Activities were threefold higher in female compared to male cardiac ventricles. Plasma cGMP and testosterone were elevated in male and female GC-A^8E/8E mice, but aldosterone was only increased in mutant male mice. Plasma and urinary creatinine concentrations were decreased and increased, respectively, but blood pressure and heart rate were unchanged in male GC-A^8E/8E mice. Heart weight to body weight ratios for GC-A^8E/8E male, but not female, mice were 12% lower with a 14% reduction in cardiomyocyte cross-sectional area. Subcutaneous injection of fsANP, a long-lived ANP analog, increased plasma cGMP and decreased aldosterone in male GC-A^WT/WT and GC-A^8E/8E mice at 15 min, but only GC-A^8E/8E mice had elevated levels of plasma cGMP and aldosterone at 60 min. fsANP reduced ventricular ERK1/2 phosphorylation to a greater extent and for a longer time in the male mutant compared to WT mice. Finally, ejection fractions were increased in male but not female hearts from GC-A^8E/8E mice. We conclude that increased phosphorylation-dependent GC-A activity decreases cardiac ERK activity, which results in smaller male hearts with improved systolic function.

A Contemporary Review of the Effects of Exercise Training on Cardiac Structure and Function and Cardiovascular Risk Profile: Insights From Imaging

Exercise is a commonly prescribed therapy for patients with established cardiovascular disease or those at high risk for de novo disease. Exercise-based, multidisciplinary programs have been associated with improved clinical outcomes post myocardial infarction and is now recommended for patients with cancer at elevated risk for cardiovascular complications. Imaging studies have documented numerous beneficial effects of exercise on cardiac structure and function, vascular function and more recently on the cardiovascular risk profile. In this contemporary review, we will discuss the effects of exercise training on imaging-derived cardiovascular outcomes. For cardiac imaging via echocardiography or magnetic resonance, we will review the effects of exercise on left ventricular function and remodeling in patients with established or at risk for cardiac disease (myocardial infarction, heart failure, cancer survivors), and the potential utility of exercise stress to assess cardiac reserve. Exercise training also has salient effects on vascular function and health including the attenuation of age-associated arterial stiffness and thickening as assessed by Doppler ultrasound. Finally, we will review recent data on the relationship between exercise training and regional adipose tissue deposition, an emerging marker of cardiovascular risk. Imaging provides comprehensive and accurate quantification of cardiac, vascular and cardiometabolic health, and may allow refinement of risk stratification in select patient populations. Future studies are needed to evaluate the clinical utility of novel imaging metrics following exercise training.

The protective effects of 17-β estradiol and SIRT1 against cardiac hypertrophy: a review

One of the major causes of morbidity and mortality worldwide is cardiac hypertrophy (CH), which leads to heart failure. Sex differences in CH can be caused by sex hormones or their receptors. The incidence of CH increases in postmenopausal women due to the decrease in female sex hormone 17-β estradiol (E2) during menopause. E2 and its receptors inhibit CH in humans and animal models. Silent information regulator 1 (SIRT1) is a NAD⁺-dependent HDAC (histone deacetylase) and plays a major role in biological processes, such as inflammation, apoptosis, and oxidative stress responses. Probably SIRT1 because of these effects, is one of the main suppressors of CH and has a cardioprotective effect. On the other hand, estrogen and its agonists are highly efficient in modulating SIRT1 expression. In the present study, we review the protective effects of E2 and SIRT1 against CH.

Sex Differences, Estrogen Metabolism and Signaling in the Development of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a complex and devastating disease with a poor long-term prognosis. While women are at increased risk for developing PAH, they exhibit superior right heart function and higher survival rates than men. Susceptibility to disease risk in PAH has been attributed, in part, to estrogen signaling. In contrast to potential pathological influences of estrogen in patients, studies of animal models reveal estrogen demonstrates protective effects in PAH. Consistent with this latter observation, an ovariectomy in female rats appears to aggravate the condition. This discrepancy between observations from patients and animal models is often called the "estrogen paradox." Further, the tissue-specific interactions between estrogen, its metabolites and receptors in PAH and right heart function remain complex; nonetheless, these relationships are essential to characterize to better understand PAH pathophysiology and to potentially develop novel therapeutic and curative targets. In this review, we explore estrogen-mediated mechanisms that may further explain this paradox by summarizing published literature related to: (1) the synthesis and catabolism of estrogen; (2) activity and functions of the various estrogen receptors; (3) the multiple modalities of estrogen signaling in cells; and (4) the role of estrogen and its diverse metabolites on the susceptibility to, and progression of, PAH as well as their impact on right heart function.

Sex-related differences in ventricular remodeling after myocardial infarction

The epidemiology, clinical features and outcome of myocardial infarction (MI) display significant differences between men and women. Prominent sex differences have also been suggested in left ventricular (LV) remodeling after MI. Ventricular remodeling refers to a deterioration of LV geometry and function often leading to heart failure (HF) development and an increased risk of adverse cardiovascular events. Women have a lower propensity to the acquisition of a spherical geometry and LV dysfunction. These differences can be attributed at least partially to a lower frequency of transmural infarction and smaller areas of microvascular obstruction in women, as well as to a less prominent activation of neuroendocrine systems and apoptotic, inflammatory and profibrotic pathways in women. Estrogens might play a role in this difference, which could partially persist even after the menopause because of a persisting intramyocardial synthesis of estrogens in women. Conversely, androgens may exert a detrimental influence. Future studies should better clarify sex differences in the predictors, clinical correlates, prognostic impact and disease mechanisms of remodeling, as well as the existence of sex-specific therapeutic targets. This research effort should hopefully allow to optimize the treatment of MI during the acute and post-acute phase, possibly through different therapeutic strategies in men and women, with the goal of reducing the risk of HF development and improving patient outcome.

Integrated transcriptomics and epigenomics reveal chamber-specific and species-specific characteristics of human and mouse hearts

DNA methylation, chromatin accessibility, and gene expression represent different levels information in biological process, but a comprehensive multiomics analysis of the mammalian heart is lacking. Here, we applied nucleosome occupancy and methylome sequencing, which detected DNA methylation and chromatin accessibility simultaneously, as well as RNA-seq, for multiomics analysis of the 4 chambers of adult and fetal human hearts, and adult mouse hearts. Our results showed conserved region-specific patterns in the mammalian heart at transcriptome and DNA methylation level. Adult and fetal human hearts showed distinct features in DNA methylome, chromatin accessibility, and transcriptome. Novel long noncoding RNAs were identified in the human heart, and the gene expression profiles of major cardiovascular diseases associated genes were displayed. Furthermore, cross-species comparisons revealed human-specific and mouse-specific differentially expressed genes between the atria and ventricles. We also reported the relationship among multiomics and found there was a bell-shaped relationship between gene-body methylation and expression in the human heart. In general, our study provided comprehensive spatiotemporal and evolutionary insights into the regulation of gene expression in the heart.

Multi-omic analyses of the four chambers of the human and mouse heart, including transcriptome, DNA methylation and chromatin accessibility, reveals characteristic patterns of gene regulation at the level of heart regions.

Computational models of cardiac hypertrophy

Cardiac hypertrophy, defined as an increase in mass of the heart, is a complex process driven by simultaneous changes in hemodynamics, mechanical stimuli, and hormonal inputs. It occurs not only during pre- and post-natal development but also in adults in response to exercise, pregnancy, and a range of cardiovascular diseases. One of the most exciting recent developments in the field of cardiac biomechanics is the advent of computational models that are able to accurately predict patterns of heart growth in many of these settings, particularly in cases where changes in mechanical loading of the heart play an import role. These emerging models may soon be capable of making patient-specific growth predictions that can be used to guide clinical interventions. Here, we review the history and current state of cardiac growth models and highlight three main limitations of current approaches with regard to future clinical application: their inability to predict the regression of heart growth after removal of a mechanical overload, inability to account for evolving hemodynamics, and inability to incorporate known growth effects of drugs and hormones on heart growth. Next, we outline growth mechanics approaches used in other fields of biomechanics and highlight some potential lessons for cardiac growth modeling. Finally, we propose a multiscale modeling approach for future studies that blends tissue-level growth models with cell-level signaling models to incorporate the effects of hormones in the context of pregnancy-induced heart growth.

Sex-Specific Features of Calcific Aortic Valve Disease

Calcific aortic valve disease (CAVD) is the most common valvular heart disease in developed countries predominantly affecting the elderly population therefore posing a large economic burden. It is a gradually progressive condition ranging from mild valve calcification and thickening, without the hemodynamic obstruction, to severe calcification impairing leaflet motion, known as aortic stenosis (AS). The progression of CAVD occurs over many years, and it is extremely variable among individuals. It is also associated with an increased risk of coronary events and mortality. The recent insights into the CAVD pathophysiology included an important role of sex. Accumulating evidence suggests that, in patients with CAVD, sex can determine important differences in the relationship between valvular calcification process, fibrosis, and aortic stenosis hemodynamic severity between men and women. Consequently, it has implications on the development of different valvular phenotypes, left ventricular hypertrophy, and cardiovascular outcomes in men and women. Along these lines, taking into account the sex-related differences in diagnosis, prognosis, and treatment outcomes is of profound importance. In this review, the sex-related differences in patients with CAVD, in terms of pathobiology, clinical phenotypes, and outcomes were discussed.

Is Cardiac Diastolic Dysfunction a Part of Post-Menopausal Syndrome?

Post-menopausal women exhibit an exponential increase in the incidence of heart failure with preserved ejection fraction compared with men of the same age, which indicates a potential role of hormonal changes in subclinical and clinical diastolic dysfunction. This paper reviews the preclinical evidence that demonstrates the involvement of estrogen in many regulatory molecular pathways of cardiac diastolic function and the clinical data that investigates the effect of estrogen on diastolic function in post-menopausal women. Published reports show that estrogen deficiency influences both early diastolic relaxation via calcium homeostasis and the late diastolic compliance associated with cardiac hypertrophy and fibrosis. Because of the high risk of diastolic dysfunction and heart failure with preserved ejection fraction in post-menopausal women and the positive effects of estrogen on preserving cardiac function, further clinical studies are needed to clarify the role of endogenous estrogen or hormone replacement in mitigating the onset and progression of heart failure with preserved ejection fraction in women.

Estrogen-related mechanisms in sex differences of hypertension and target organ damage

Hypertension (HTN) is a primary risk factor for cardiovascular (CV) events, target organ damage (TOD), premature death and disability worldwide. The pathophysiology of HTN is complex and influenced by many factors including biological sex. Studies show that the prevalence of HTN is higher among adults aged 60 and over, highlighting the increase of HTN after menopause in women. Estrogen (E2) plays an important role in the development of systemic HTN and TOD, exerting several modulatory effects. The influence of E2 leads to alterations in mechanisms regulating the sympathetic nervous system, renin-angiotensin-aldosterone system, body mass, oxidative stress, endothelial function and salt sensitivity; all associated with a crucial inflammatory state and influenced by genetic factors, ultimately resulting in cardiac, vascular and renal damage in HTN. In the present article, we discuss the role of E2 in mechanisms accounting for the development of HTN and TOD in a sex-specific manner. The identification of targets with therapeutic potential would contribute to the development of more efficient treatments according to individual needs.

Amyloidosis in surgically resected atrial appendages: a study of 345 consecutive cases with clinical implications

Histomorphologic parameters of atrial appendages removed during the Cox-Maze procedure have been shown to correlate with recurrence of atrial fibrillation. While amyloid deposition has been noted within atrial appendages, the incidence and significance remains incompletely understood. More accurate amyloid typing methodologies and targeted pharmacotherapeutics have recently been developed, prompting pathologists to provide more detailed information about the type of amyloid identified in such samples. This study sought to fully characterize the morphologic characteristics of atrial amyloid as well as its incidence and clinical significance. Tissue archives were queried for atrial appendages removed during the cardiac surgeries (2010-2014). Patient demographics, imaging features, and salient clinical findings were recorded. Pattern and extent of amyloid deposition were recorded. Typing of the amyloid protein, when present, was performed on a subset of cases by laser capture microdissection with mass spectrometry-based proteomic analysis. A total of 383 atrial appendages from 345 consecutive patients were included in the study (mean age, 69 years; range, 26-92 years). Amyloid was present in 46% of patients. A linear relationship was observed between age and presence of atrial amyloidosis. Women were more likely to have atrial amyloidosis. Two distinct morphologies of amyloid were observed: filamentous and nonfilamentous, and correlated perfectly with amyloid type (filamentous = AANF-type amyloid; nonfilamentous = ATTR-type amyloid). Filamentous deposits were observed in 91% of those with amyloid. Amyloid was more likely to be found in the left atrial appendage than the right. Patients with atrial amyloid, irrespective of type, were more likely to have experienced stroke or TIA and more likely to have atrial arrhythmia preoperatively. Postoperatively, those with atrial amyloid are more likely to experience recurrence of arrhythmia than those who did not have atrial amyloid. Understanding the morphologic characteristics of AANF-type amyloid will allow for identification by the light microscopy and obviates the need for expensive ancillary typing techniques. The finding of nonfilamentous amyloid, should still prompt confirmation of amyloid type so that targeted therapy may be employed.

Sex-specific cardiac phenotype and clinical outcomes in patients with hypertrophic cardiomyopathy

BACKGROUND

It is unknown whether sex-specific differences in mortality observed in HCM are due to older age of women at presentation, or whether women have greater degree of LV myopathy than men.

METHODS

We retrospectively compared clinical/imaging characteristics and outcomes between women and men in our overall cohort composed of 728 HCM patients, and in an age-matched subgroup comprised of 400 age-matched patients. We examined sex-specific differences in LV myopathy, and dissected the influence of age and sex on outcomes. LV myopathy was assessed by measuring LV mass, LVEF, global peak longitudinal systolic strain (LV-GLS), diastolic function (E/A, E/e'), late gadolinium enhancement (LV-LGE) and myocardial blood flow (MBF) at rest/stress. The primary endpoint was a composite outcome, comprising heart failure (HF), atrial fibrillation (AFib), ventricular tachycardia/fibrillation (VT/VF) and death; individual outcomes were defined as the secondary endpoint.

RESULTS

Women in the overall cohort were older by 6 years. Women were more symptomatic and more likely to have obstructive HCM. Women had smaller LV cavity size, stroke volume and LV mass, higher indexed maximum wall thickness (IMWT), more hyperdynamic LVEF and higher/similar LV-GLS. Women had similar LV-LGE and E/A, but higher E/e' and rest/stress MBF. Female sex was independently associated with the composite outcome in the overall cohort, and with HF in the overall cohort and age-matched subgroup after adjusting for obstructive HCM, LA diameter, LV-GLS.

CONCLUSIONS

Our results suggest that sex-specific differences in LV geometry, hyper-contractility and diastolic function, not greater degree of LV myopathy, contribute to a higher, age-independent risk of diastolic HF in women with HCM.

Analysis of the Associations between Obesity Indices and Left Ventricular Mass

The aims of this study were to investigate the association between different obesity indices and left ventricular mass (LVM) and to develop interventions for obese hypertensive patients to delay the progression of left ventricular hypertrophy (LVH). The association between the visceral adiposity index (VAI) and LVM was explored using multiple regression analysis in all subjects (n = 1,035), the subgroups of patients aged < 65 (n = 713) and ≥65 years (n = 322), and perimenopausal women (n = 319). The VAI was the only obesity index associated with LVH (OR = 1.134; 95% CI 1.025–1.254, p = 0.015). In the subgroup of patients aged < 65 years, both systolic blood pressure and VAI were risk factors for LVH. However, in the subgroup aged ≥65 years, only systolic blood pressure was a risk factor, and there was no association between VAI and LVH (p = 0.13). Perimenopause was an independent risk factor (OR = 1.786; 95% CI 1.125–2.837, p = 0.014). Reducing the VAI rather than the BMI or waist circumference may prevent LVH complications in obese hypertensive patients. For patients aged < 65 years strict control of blood pressure and obesity may be important, and for those aged ≥65 years blood pressure control should be the priority. Estrogen replacement may be useful in postmenopausal women to prevent LVH.

Sex-Specific Ventricular and Vascular Adaptations to Exercise

Increasing data suggest that there are sex differences in ventricular and vascular adaptations to aerobic (endurance) exercise, which may be attributed to different physical and physiological features in men and women. Despite that cardiovascular control during acute exercise at the same relative work rate (e.g., the percentage of peak oxygen uptake) appears to be similar between the sexes, women have blunted responses or adaptations to prolonged (e.g., ≥1 year) exercise training compared with men. Currently, there is little evidence to suggest that exercise-induced vascular adaptations are different between men and women. Furthermore, sex differences in skeletal muscle adaptations to exercise, and how this influences cardiovascular function, remain unclear. Identifying potential differences and the mechanisms behind such exercise-induced adaptations is important for the optimization of exercise interventions between men and women across the life span.

The protective role of estrogen and estrogen receptors in cardiovascular disease and the controversial use of estrogen therapy

Epidemiologic studies have previously suggested that premenopausal females have reduced incidence of cardiovascular disease (CVD) when compared to age-matched males, and the incidence and severity of CVD increases postmenopause. The lower incidence of cardiovascular disease in women during reproductive age is attributed at least in part to estrogen (E2). E2 binds to the traditional E2 receptors (ERs), estrogen receptor alpha (ERα), and estrogen receptor beta (ERβ), as well as the more recently identified G-protein-coupled ER (GPR30), and can exert both genomic and non-genomic actions. This review summarizes the protective role of E2 and its receptors in the cardiovascular system and discusses its underlying mechanisms with an emphasis on oxidative stress, fibrosis, angiogenesis, and vascular function. This review also presents the sexual dimorphic role of ERs in modulating E2 action in cardiovascular disease. The controversies surrounding the clinical use of exogenous E2 as a therapeutic agent for cardiovascular disease in women due to the possible risks of thrombotic events, cancers, and arrhythmia are also discussed. Endogenous local E2 biosynthesis from the conversion of testosterone to E2 via aromatase enzyme offers a novel therapeutic paradigm. Targeting specific ERs in the cardiovascular system may result in novel and possibly safer therapeutic options for cardiovascular protection.

Mechanistic Pathways of Sex Differences in Cardiovascular Disease

Major differences between men and women exist in epidemiology, manifestation, pathophysiology, treatment, and outcome of cardiovascular diseases (CVD), such as coronary artery disease, pressure overload, hypertension, cardiomyopathy, and heart failure. Corresponding sex differences have been studied in a number of animal models, and mechanistic investigations have been undertaken to analyze the observed sex differences. We summarize the biological mechanisms of sex differences in CVD focusing on three main areas, i.e., genetic mechanisms, epigenetic mechanisms, as well as sex hormones and their receptors. We discuss relevant subtypes of sex hormone receptors, as well as genomic and nongenomic, activational and organizational effects of sex hormones. We describe the interaction of sex hormones with intracellular signaling relevant for cardiovascular cells and the cardiovascular system. Sex, sex hormones, and their receptors may affect a number of cellular processes by their synergistic action on multiple targets. We discuss in detail sex differences in organelle function and in biological processes. We conclude that there is a need for a more detailed understanding of sex differences and their underlying mechanisms, which holds the potential to design new drugs that target sex-specific cardiovascular mechanisms and affect phenotypes. The comparison of both sexes may lead to the identification of protective or maladaptive mechanisms in one sex that could serve as a novel therapeutic target in one sex or in both.

Estrogenic endocrine disruptors: Molecular mechanisms of action

A comprehensive summary of more than 450 estrogenic chemicals including estrogenic endocrine disruptors is provided here to understand the complex and profound impact of estrogen action. First, estrogenic chemicals are categorized by structure as well as their applications, usage and effects. Second, estrogenic signaling is examined by the molecular mechanism based on the receptors, signaling pathways, crosstalk/bypassing and autocrine/paracrine/homeostatic networks involved in the signaling. Third, evaluation of estrogen action is discussed by focusing on the technologies and protocols of the assays for assessing estrogenicity. Understanding the molecular mechanisms of estrogen action is important to assess the action of endocrine disruptors and will be used for risk management based on pathway-based toxicity testing.

Statement on pregnancy in pulmonary hypertension from the Pulmonary Vascular Research Institute

Pregnancy outcomes in patients with pulmonary hypertension remain poor despite advanced therapies. Although consensus guidelines recommend against pregnancy in pulmonary hypertension, it may nonetheless occasionally occur. This guideline document sought to discuss the state of knowledge of pregnancy effects on pulmonary vascular disease and to define usual practice in avoidance of pregnancy and pregnancy management. This guideline is based on systematic review of peer-reviewed, published literature identified with MEDLINE. The strength of the literature was graded, and when it was inadequate to support high-level recommendations, consensus-based recommendations were formed according to prespecified criteria. There was no literature that met standards for high-level recommendations for pregnancy management in pulmonary hypertension. We drafted 38 consensus-based recommendations on pregnancy avoidance and management. Further, we identified the current state of knowledge on the effects of sex hormones during pregnancy on the pulmonary vasculature and right heart and suggested areas for future study. There is currently limited evidence-based knowledge about both the basic molecular effects of sex hormones and pregnancy on the pulmonary vasculature and the best practices in contraception and pregnancy management in pulmonary hypertension. We have drafted 38 consensus-based recommendations to guide clinicians in these challenging topics, but further research is needed in this area to define best practices and improve patient outcomes.

MicroRNA-23a participates in estrogen deficiency induced gap junction remodeling of rats by targeting GJA1

Increased incidence of arrhythmias in women after menopause has been widely documented, which is considered to be related to estrogen (E2) deficiency induced cardiac electrophysiological abnormalities. However, its molecular mechanism remains incompletely clear. In the present study, we found cardiac conduction blockage in post-menopausal rats. Thereafter, the results showed that cardiac gap junctions were impaired and Connexin43 (Cx43) expression was reduced in the myocardium of post-menopausal rats. The phenomenon was also observed in ovariectomized (OVX) rats, which was attenuated by E2 supplement. Further study displayed that microRNA-23a (miR-23a) level was significantly increased in both post-menopausal and OVX rats, which was reversed by daily E2 treatment after OVX. Importantly, forced overexpression of miR-23a led to gap junction impairment and Cx43 downregulation in cultured cardiomyocytes, which was rescued by suppressing miR-23a by transfection of miR-23a specific inhibitory oligonucleotide (AMO-23a). GJA1 was identified as the target gene of miR-23a by luciferase assay and miRNA-masking antisense ODN (miR-Mask) assay. We also found that E2 supplement could reverse cardiac conduction blockage, Cx43 downregulation, gap junction remodeling and miR-23a upregulation in post-menopausal rats. These findings provide the evidence that miR-23a mediated repression of Cx43 participates in estrogen deficiency induced damages of cardiac gap junction, and highlights a new insight into molecular mechanism of post-menopause related arrhythmia at the microRNA level.

Oestrogen inhibits BMP4-induced BMP4 expression in cardiomyocytes: a potential mechanism of oestrogen-mediated protection against cardiac hypertrophy

BACKGROUND AND PURPOSE

Oestrogen inhibits cardiac hypertrophy and bone morphogenetic protein-4 (BMP4) induces cardiac hypertrophy. Here we have studied the inhibition by oestrogen of BMP4 expression in cardiomyocytes.

EXPERIMENTAL APPROACH

Cultures of neonatal rat cardiomyocytes were used in in vitro experiments. Bilatαl ovariectomy (OVX) was carried out in female Kunming mice and cardiac hypertrophy was induced by transverse aortic constriction (TAC).

KEY RESULTS

Oestrogen inhibited BMP4-induced cardiomyocyte hypertrophy and BMP4 expression in vitro. The inhibition of BMP4-induced BMP4 protein expression by oestrogen was prevented by the inhibitor of oestrogen receptor-β, PHTPP, but not by the inhibitor of oestrogen receptor-α MPP. BMP4 induced smad1/5/8 activation, which was not affected by oestrogen in cardiomyocytes. BMP4 induced JNK but not ERK1/2 and p38 activation, and activated JNK was inhibited by oestrogen. Treatment with the p38 inhibitor SB203580 or the JNK inhibitor SP600125 inhibited BMP4-induced BMP4 expression in cardiomyocytes, but the ERK1/2 inhibitor U0126 increased BMP4-induced BMP4 expression, indicating that JNK, ERK1/2 and p38 MAPKs were all involved, although only JNK activation contributed to the inhibition of BMP4-induced BMP4 expression by oestrogen. TAC induced significant heart hypertrophy in OVX mice in vivo and oestrogen replacement inhibited TAC-induced heart hypertrophy in OVX mice. In parallel with the data of heart hypertrophy, oestrogen replacement significantly reduced the increased BMP4 protein expression in TAC-treated OVX mice.

CONCLUSIONS AND IMPLICATIONS

Oestrogen treatment inhibited BMP4-induced BMP4 expression in cardiomyocytes through stimulating oestrogen receptor-β and inhibiting JNK activation. Our results provide a novel mechanism underlying oestrogen-mediated protection against cardiac hypertrophy.

Effects of biological sex on the pathophysiology of the heart

Cardiovascular diseases are the leading causes of death in men and women in industrialized countries. While the effects of biological sex on cardiovascular pathophysiology have long been known, the sex-specific mechanisms mediating these processes have been further elucidated over recent years. This review aims at analysing the sex-based differences in cardiac structure and function in adult mammals, and the sex-based differences in the main molecular mechanisms involved in the response of the heart to pathological situations. It emerged from this review that the sex-based difference is a variable that should be dealt with, not only in basic science or clinical research, but also with regards to therapeutic approaches.

Genetic background defines the regulation of postnatal cardiac growth by 17β-estradiol through a β-catenin mechanism

Estrogen regulates several biological processes in health and disease. Specifically, estrogen exerts antihypertrophic effects in the diseased heart. However, its role in the healthy heart remains elusive. Our initial aim was to identify the effects of 17β-estradiol (E2) on cardiac morphology and global gene expression in the healthy mouse heart. Two-month-old C57BL/6J mice were ovariectomized and treated with E2 or vehicle for 3 months. We report that E2 induced physiological hypertrophic growth in the healthy C57BL/6J mouse heart characterized by an increase in nuclear β-catenin. Hypothesizing that β-catenin mediates these effects of E2, we employed a model of cardiac β-catenin deletion. Our surprising finding is that E2 had the opposite effects in wild-type littermates, which were actually on the C57BL/6N background. Notably, E2 exerted no significant effect in hearts of mice with depleted β-catenin. We further demonstrate an E2-dependent increase in glycogen synthase kinase 3β (GSK3β) phosphorylation and endosomal markers in C57BL/6J but not C57BL/6N mice. Together, these findings indicate an E2-driven inhibition of GSK3β and consequent activation of β-catenin in C57BL/6J mice, whereas the opposite occurs in C57BL/6N mice. In conclusion, E2 exerts divergent effects on postnatal cardiac growth in mice with distinct genetic backgrounds modulating members of the GSK3β/β-catenin cascade.

PDE5 inhibitor efficacy is estrogen dependent in female heart disease

Inhibition of cGMP-specific phosphodiesterase 5 (PDE5) ameliorates pathological cardiac remodeling and has been gaining attention as a potential therapy for heart failure. Despite promising results in males, the efficacy of the PDE5 inhibitor sildenafil in female cardiac pathologies has not been determined and might be affected by estrogen levels, given the hormone's involvement in cGMP synthesis. Here, we determined that the heart-protective effect of sildenafil in female mice depends on the presence of estrogen via a mechanism that involves myocyte eNOS-dependent cGMP synthesis and the cGMP-dependent protein kinase Iα (PKGIα). Sildenafil treatment failed to exert antiremodeling properties in female pathological hearts from Gαq-overexpressing or pressure-overloaded mice after ovary removal; however, estrogen replacement restored the effectiveness of sildenafil in these animals. In females, sildenafil-elicited myocardial PKG activity required estrogen, which stimulated tonic cardiomyocyte cGMP synthesis via an eNOS/soluble guanylate cyclase pathway. In contrast, eNOS activation, cGMP synthesis, and sildenafil efficacy were not estrogen dependent in male hearts. Estrogen and sildenafil had no impact on pressure-overloaded hearts from animals expressing dysfunctional PKGIα, indicating that PKGIα mediates antiremodeling effects. These results support the importance of sex differences in the use of PDE5 inhibitors for treating heart disease and the critical role of estrogen status when these agents are used in females.

Estrogen therapy, independent of timing, improves cardiac structure and function in oophorectomized mRen2.Lewis rats

OBJECTIVE

mRen2.Lewis rats exhibit exacerbated increases in blood pressure, left ventricular (LV) remodeling, and diastolic impairment after the loss of estrogens. In this same model, depletion of estrogens has marked effects on the cardiac biopterin profile concomitant with suppressed nitric oxide release. With respect to the establishment of overt systolic hypertension after oophorectomy (OVX), we assessed the effects of timing long-term 17β-estradiol (E2) therapy on myocardial function, myocardial structure, and the cardiac nitric oxide system.

METHODS

OVX (n = 24) or sham operation (Sham; n = 13) was performed in 4-week-old female mRen2.Lewis rats. After randomization, OVX rats received E2 immediately (OVX + E2-early; n = 7), E2 at 11 weeks of age (OVX + E2-late; n = 8), or no E2 at all (OVX; n = 9).

RESULTS

E2-early was associated with lower body weight, less hypertension-related cardiac remodeling, and decreased LV filling pressure compared with OVX rats without E2 supplementation. E2-late similarly attenuated the adverse effects of ovarian hormone loss on tissue Doppler-derived LV filling pressures and perivascular fibrosis, and significantly improved myocardial relaxation or mitral annular velocity (e'). Early and late exposures to E2 decreased dihydrobiopterin, but only E2-late yielded significant increases in cardiac nitrite concentrations.

CONCLUSIONS

Although there are some similarities between E2-early and E2-late treatments in relation to preservation of diastolic function and cardiac structure after OVX, the lusitropic potential of E2 is most consistent with late supplementation. The cardioprotective effects of E2-late are independent of blood pressure and may have occurred through regulation of cardiac biopterins and nitric oxide production.

Sex differences in animal models for cardiovascular diseases and the role of estrogen

Clinical findings show sex differences in the manifestation of a number of cardiovascular diseases (CVD). However, the underlying molecular mechanisms are incompletely understood. Multiple animal models suggest sex differences in the manifestation of CVD, and provide strong experimental evidence that different major pathways are regulated in a sex-specific manner. In most animal studies females display a lower mortality, less severe hypertrophy, and better preserved cardiac function compared with male counterparts. The data support the hypothesis that female sex and/or the sex hormone estrogen (17β-estradiol; E2) may contribute to the sexual dimorphism in the heart and to a better outcome of cardiac diseases in females. To improve our understanding of the sex-based molecular and cellular mechanisms of CVD and to develop new therapeutic strategies, the use of appropriate animal models is essential. This review highlights recent findings from animal models relevant for studying the mechanisms of sexual dimorphisms in the healthy and diseased heart, focusing on physiological hypertrophy (exercise), pathological hypertrophy (volume and pressure overload induced hypertrophy), and heart failure (myocardial infarction). Furthermore, the potential effects of E2 in these models will be discussed.

Estrogen paradox in pulmonary hypertension: current controversies and future perspectives

Although the incidence of pulmonary hypertension is higher in female patients, numerous experimental studies have demonstrated better outcome in female animals, exacerbation of the disease after ovariectomy, and a strong protective effect of estrogen: a phenomenon known as the "estrogen paradox" of pulmonary hypertension. On the other hand, some clinical studies have indirectly linked estrogen to increased risk of portopulmonary hypertension, whereas others implicate increased estrogen metabolism and high levels of certain estrogen metabolites in promoting pulmonary vascular remodeling in familial pulmonary arterial hypertension. In this review we investigate the estrogen paradox through highlighting the differential receptor-mediated effects of estrogen. Although estrogen and estrogen receptor-based therapies have shown promise in rescuing preexisting pulmonary hypertension in animals, their role is yet to be defined in humans.

Myocardial AKT: the omnipresent nexus

One of the greatest examples of integrated signal transduction is revealed by examination of effects mediated by AKT kinase in myocardial biology. Positioned at the intersection of multiple afferent and efferent signals, AKT exemplifies a molecular sensing node that coordinates dynamic responses of the cell in literally every aspect of biological responses. The balanced and nuanced nature of homeostatic signaling is particularly essential within the myocardial context, where regulation of survival, energy production, contractility, and response to pathological stress all flow through the nexus of AKT activation or repression. Equally important, the loss of regulated AKT activity is primarily the cause or consequence of pathological conditions leading to remodeling of the heart and eventual decompensation. This review presents an overview compendium of the complex world of myocardial AKT biology gleaned from more than a decade of research. Summarization of the widespread influence that AKT exerts upon myocardial responses leaves no doubt that the participation of AKT in molecular signaling will need to be reckoned with as a seemingly omnipresent regulator of myocardial molecular biological responses.

Estrogen rescues preexisting severe pulmonary hypertension in rats

RATIONALE

Pulmonary hypertension (PH) is characterized by progressive increase in pulmonary artery pressure leading to right ventricular (RV) hypertrophy, RV failure, and death. Current treatments only temporarily reduce severity of the disease, and an ideal therapy is still lacking.

OBJECTIVES

Estrogen pretreatment has been shown to attenuate development of PH. Because PH is not often diagnosed early, we examined if estrogen can rescue preexisting advanced PH.

METHODS

PH was induced in male rats with monocrotaline (60 mg/kg). At Day 21, rats were either treated with 17-β estradiol or estrogen (E2, 42.5 μg/kg/d), estrogen receptor-β agonist (diarylpropionitrile, 850 μg/kg/d), or estrogen receptor α-agonist (4,4',4"-[4-Propyl-(1H)-pyrazole-1,3,5-triyl] trisphenol, 850 μg/kg/d) for 10 days or left untreated to develop RV failure. Serial echocardiography, cardiac catheterization, immunohistochemistry, Western blot, and real-time polymerase chain reaction were performed.

MEASUREMENTS AND MAIN RESULTS

Estrogen therapy prevented progression of PH to RV failure and restored lung and RV structure and function. This restoration was maintained even after removal of estrogen at Day 30, resulting in 100% survival at Day 42. Estradiol treatment restored the loss of blood vessels in the lungs and RV. In the presence of angiogenesis inhibitor TNP-470 (30 mg/kg) or estrogen receptor-β antagonist (PHTPP, 850 μg/kg/d), estrogen failed to rescue PH. Estrogen receptor-β selective agonist was as effective as estrogen in rescuing PH.

CONCLUSIONS

Estrogen rescues preexisting severe PH in rats by restoring lung and RV structure and function that are maintained even after removal of estrogen. Estrogen-induced rescue of PH is associated with stimulation of cardiopulmonary neoangiogenesis, suppression of inflammation, fibrosis, and RV hypertrophy. Furthermore, estrogen rescue is likely mediated through estrogen receptor-β.

Tetrahydrobiopterin restores diastolic function and attenuates superoxide production in ovariectomized mRen2.Lewis rats

After oophorectomy, mRen2.Lewis rats exhibit diastolic dysfunction associated with elevated superoxide, increased cardiac neuronal nitric oxide synthase (nNOS) expression, and diminished myocardial tetrahydrobiopterin (BH₄) content, effects that are attenuated with selective nNOS inhibition. BH₄ is an essential cofactor of nNOS catalytic activity leading to nitric oxide production. Therefore, we assessed the effect of 4 wk BH₄ supplementation on diastolic function and left ventricular (LV) remodeling in oophorectomized mRen2.Lewis rats compared with sham-operated controls. Female mRen2.Lewis rats underwent either bilateral ovariectomy (OVX) (n = 19) or sham operation (n = 13) at 4 wk of age. Beginning at 11 wk of age, OVX rats were randomized to receive either BH₄ (10 mg/kg · d) or saline, whereas the sham rats received saline via sc mini-pumps. Loss of ovarian hormones reduced cardiac BH₄ when compared with control hearts; this was associated with impaired myocardial relaxation, augmented filling pressures, increased collagen deposition, and thickened LV walls. Additionally, superoxide production increased and nitric oxide decreased in hearts from OVX compared with sham rats. Chronic BH₄ supplementation after OVX improved diastolic function and attenuated LV remodeling while restoring myocardial nitric oxide release and preventing reactive oxygen species generation. These data indicate that BH₄ supplementation protects against the adverse effects of ovarian hormonal loss on diastolic function and cardiac structure in mRen2.Lewis rats by restoring myocardial NO release and mitigating myocardial O₂⁻ generation. Whether BH₄ supplementation is a therapeutic option for the management of diastolic dysfunction in postmenopausal women will require direct testing in humans.

Stimulation of cardiac apoptosis in ovariectomized hypertensive rats: potential role of the renin-angiotensin system

OBJECTIVES

The mechanisms underlying the increased cardiovascular risk after menopause are poorly understood. Estrogens modulate the cardiac renin-angiotensin system (RAS) and influence cardiac adaptation to afterload. To investigate whether the loss of the natural inhibition of the RAS by estrogen may be linked to an increase of cardiac apoptosis, we studied 17β-estradiol (E2) and/or angiotensin-converting enzyme (ACE) inhibitor treatment effects on cardiomyocyte survival in ovariectomized spontaneously hypertensive rats (SHRs).

METHODS

Five groups of female SHRs were evaluated for 8 weeks. One group served as nonovariectomized control; the other four groups underwent bilateral ovariectomy and were randomized to receive 60-day-release pellets containing placebo or 0.5 mg of E2, the ACE inhibitor ramipril at the dosage of 2.5 mg/kg per day, or the combination of the two treatments.

RESULTS

Ovariectomy increased cardiomyocyte apoptosis and induced proapoptotic changes of Bcl-2 and Bax genes and proteins. These modifications were associated with an upregulation of ACE and angiotensin II type 1 (AT1) receptor genes. Ramipril was as effective as E2 in preventing cardiac apoptosis and in restoring cardiac brain natriuretic peptide in association with reduced cardiac ACE and AT1 receptor gene expression. In contrast to the ramipril treatment, the favorable effect of E2 on cardiac apoptosis occurred independently from changes in SBP. No synergistic effect was observed when the two treatments were combined.

CONCLUSION

These data show that ovariectomy stimulates myocardium apoptosis by a mechanism involving Bax and Bcl-2 genes. The antiapoptotic effect of E2 and ACE inhibitor treatment was linked to a downregulation of cardiac RAS.

Gender and the renin-angiotensin-aldosterone system

Premenopausal women are protected to some extent from cardiovascular and kidney diseases. Because this protection weakens after menopause, sex hormones are believed to play an important role in the pathogenesis of cardiovascular and kidney diseases. The cardiovascular system and the kidneys are regulated by the renin-angiotensin-aldosterone system (RAAS), which in turn, appears to be regulated by sex hormones. In general, oestrogen increases angiotensinogen levels and decreases renin levels, angiotensin-converting enzyme (ACE) activity, AT(1) receptor density, and aldosterone production. Oestrogen also activates counterparts of the RAAS such as natriuretic peptides, AT(2) receptor density, and angiotensinogen (1-7). Progesterone competes with aldosterone for mineralocorticoid receptor. Less is known about androgens, but testosterone seems to increase renin levels and ACE activity. These effects of sex hormones on the RAAS can explain at least some of the gender differences in cardiovascular and kidney diseases.

New insights into sexual dimorphism during progression of heart failure and rhythm disorders

Neurohormonal imbalance is a key determinant of the progression of heart failure (HF), which results in an elevated risk of mortality. A better understanding of mechanisms involved may influence treatment strategies. The incidence and prevalence of HF are lower in women. We explored sexual dimorphism in the progression of HF using a mice model of neurohormonal-dependent HF. Male and female mice overexpressing the human beta2-adrenergic receptor (TG4 strain) develop HF. We compared TG4 animals with age-matched wild-type controls. Cardiac function was studied in vivo by echocardiography and electrocardiography. Histological studies were performed. Conduction parameters were assessed by intracardiac electrophysiological exploration, as was the occurrence of spontaneous and inducible arrhythmias. The patch-clamp technique was used to determine the cellular electrophysiological profile. The role of hormonal status in HF progression was investigated by surgical gonadectomy. High mortality rate was observed in TG4 mice with a dramatic difference between males and females. Male TG4 mice exhibited intraventricular conduction abnormalities, as measured by infrahisian interval and QRS durations potentially determining reentrant circuits and increasing susceptibility to arrhythmia. The severity of HF was correlated with the degree of fibrosis, which was modulated by the gonadal hormones. Action potentials recorded from male and female left ventricular cardiomyocytes were indistinguishable, although both sexes exhibited delayed repolarization when compared with their wild-type counterparts. In conclusion, female TG4 mice were better protected than males against cardiac remodeling and rhythm disorders. A link between fibrosis, conduction time, and mortality was established in relation with sex hormones.

Signaling responses after exposure to 5 alpha-dihydrotestosterone or 17 beta-estradiol in norepinephrine-induced hypertrophy of neonatal rat ventricular myocytes

Androgens appear to enhance, whereas estrogens mitigate, cardiac hypertrophy. However, signaling pathways in cells for short (3 min) and longer term (48 h) treatment with 17beta-estradiol (E2) or 5 alpha-dihydrotestosterone (DHT) are understudied. We compared the effect of adrenergic stimulation by norepinephrine (NE; 1 microM) alone or in combination with DHT (10 nM) or E2 (10 nM) treatment in neonatal rat ventricular myocytes (NRVMs) by cell area, protein synthesis, sarcomeric structure, gene expression, phosphorylation of extracellular signal-regulated (ERK), and focal adhesion kinases (FAK), and phospho-FAK nuclear localization. NE alone elicited the expected hypertrophy and strong sarcomeric organization, and DHT alone gave a similar but more modest response, whereas E2 did not alter cell size. Effects of NE dominated when used with either E2 or DHT with all combinations. Both sex hormones alone rapidly activated FAK but not ERK. Long-term or brief exposure to E2 attenuated NE-induced FAK phosphorylation, whereas DHT had no effect. Neither hormone altered NE-elicited ERK activation. Longer term exposure to E2 alone reduced FAK phosphorylation and reduced nuclear phospho-FAK, whereas its elevation was seen in the presence of NE with both sex hormones. The mitigating effects of E2 on the NE-elicited increase in cell size and the hypertrophic effect of DHT in NRVMs are in accordance with results observed in whole animal models. This is the first report of rapid, nongenomic sex hormone signaling via FAK activation and altered FAK trafficking to the nucleus in heart cells.

Androgen-androgen receptor system protects against angiotensin II-induced vascular remodeling

Age-related andropause promotes cardiovascular disease in males. Although we had previously reported that the androgen-androgen receptor (AR) system plays important roles in cardiac growth and remodeling, the system's involvement in vascular remodeling remains unclear. To clarify this role, 25-wk-old male AR knockout (ARKO) mice and littermate male wild-type (WT) mice were divided into two groups with and without angiotensin II (Ang II) administration (2.0 mg/kg . d) for 14 d, respectively. No morphological differences in the coronary artery and thoracic aorta were observed between the groups without Ang II. Ang II stimulation markedly increased medial thickness and perivascular fibrosis in ARKO mice, with enhanced TGF-beta1, collagen type I, and collagen type III gene expression in the aorta. Ang II stimulation also prominently increased superoxide production, lipid peroxidation, and gene expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase components in ARKO mice compared with WT mice. In addition, phosphorylation of c-Jun N-terminal kinase (JNK) and phosphorylated (Smad2/3) was remarkably enhanced in Ang II-treated ARKO mice compared with Ang II-treated WT mice. Notably, daily urinary nitric oxide (NO) metabolites excretion as a marker of NO bioavailability, aortic endothelial NO synthase expression and phosphorylation, and Akt phosphorylation were significantly reduced in ARKO mice compared with WT mice, regardless of Ang II stimulation. In conclusion, the androgen-AR system is required for the preservation of NO bioavailability through Akt-endothelial NO synthase system activation and exerts protective effects against Ang II-induced vascular remodeling by regulating oxidative stress, c-Jun N-terminal kinase (JNK) signaling, and the TGF-beta-phosphorylated Smad pathway.

Estrogen inhibits cardiac hypertrophy: role of estrogen receptor-beta to inhibit calcineurin

Estrogen has been reported to prevent development of cardiac hypertrophy in female rodent models and in humans. However, the mechanisms of sex steroid action are incompletely understood. We determined the cellular effects by which 17beta-estradiol (E2) inhibits angiotensin II (AngII)-induced cardiac hypertrophy in vivo. Two weeks of angiotensin infusion in female mice resulted in marked hypertrophy of the left ventricle, exacerbated by the loss of ovarian steroid hormones from oophorectomy. Hypertrophy was 51% reversed by the administration of E2 (insertion of 0.1 mg/21-d-release tablets). The effects of E2 were mainly mediated by the estrogen receptor (ER) beta-isoform, because E2 had little effect in ERbeta-null mice but comparably inhibited AngII-induced hypertrophy in wild-type or ERalpha-null mice. AngII induced a switch of myosin heavy chain production from alpha to beta, but this was inhibited by E2 via ERbeta. AngII-induced ERK activation was also inhibited by E2 through the beta-receptor. E2 stimulated brain natriuretic peptide protein expression and substantially prevented ventricular interstitial cardiac fibrosis (collagen deposition) as induced by AngII. Importantly, E2 inhibited calcineurin activity that was stimulated by AngII, related to E2 stimulating the modulatory calcineurin-interacting protein (MCIP) 1 gene and protein expression. E2 acting mainly through ERbeta mitigates the important signaling by AngII that produces cardiac hypertrophy and fibrosis in female mice.

Functional effects and molecular mechanisms of subtype-selective ERalpha and ERbeta agonists in the cardiovascular system

Gender differences in the development of cardiovascular disease suggested for a protective function of estrogens in heart disease. The negative or neutral outcome of clinical trials on hormone replacement therapy provides clear evidence that the role of female sex hormones in the cardiovascular system is more complex than previously thought. In particular, the function of estrogens can not be understood without detailed knowledge on the specific function of both estrogen receptor subtypes in the heart and in the vasculature. In here, we review recent studies on subtype selective ERalpha and ERbeta agonists in different animal models of hypertension, cardiac hypertrophy and vascular inflammation. The results indicate that the activation of specific ER subtypes confers specific as well as redundant protective effects in hypertensive heart disease that might ultimately translate into novel treatment options for hypertensive heart disease.