Upregulation of Mitochondrial Sirt3 and Alleviation of the Inflammatory Phenotype in Macrophages by Estrogen.

BACKGROUND: Aging and comorbidities like type 2 diabetes and obesity contribute to the development of chronic systemic inflammation, which impacts the development of heart failure and vascular disease. Increasing evidence suggests a role of pro-inflammatory M1 macrophages in chronic inflammation. A shift of metabolism from mitochondrial oxidation to glycolysis is essential for the activation of the pro-inflammatory M1 phenotype. Thus, reprogramming the macrophage metabolism may alleviate the pro-inflammatory phenotype and protect against cardiovascular diseases. In the present study, we hypothesized that the activation of estrogen receptors leads to the elevation of the mitochondrial deacetylase Sirt3, which supports mitochondrial function and mitigates the pro-inflammatory phenotype in macrophages. MATERIALS AND METHODS: Experiments were performed using the mouse macrophage cell line RAW264.7, as well as primary male or female murine bone marrow macrophages (BMMs). Macrophages were treated for 24 h with estradiol (E2) or vehicle (dextrin). The effect of E2 on Sirt3 expression was investigated in pro-inflammatory M1, anti-inflammatory/immunoregulatory M2, and naïve M0 macrophages. Mitochondrial respiration was measured by Seahorse assay, and protein expression and acetylation were determined by western blotting. RESULTS: E2 treatment upregulated mitochondrial Sirt3, reduced mitochondrial protein acetylation, and increased basal mitochondrial respiration in naïve RAW264.7 macrophages. Similar effects on Sirt3 expression and mitochondrial protein acetylation were observed in primary female but not in male murine BMMs. Although E2 upregulated Sirt3 in naïve M0, pro-inflammatory M1, and anti-inflammatory/immunoregulatory M2 macrophages, it reduced superoxide dismutase 2 acetylation and suppressed mitochondrial reactive oxygen species formation only in pro-inflammatory M1 macrophages. E2 alleviated the pro-inflammatory phenotype in M1 RAW264.7 cells. CONCLUSIONS: The study suggests that E2 treatment upregulates Sirt3 expression in macrophages. In primary BMMs, female-specific Sirt3 upregulation was observed. The Sirt3 upregulation was accompanied by mitochondrial protein deacetylation and the alleviation of the oxidative and pro-inflammatory phenotype in M1 macrophages. Thus, the E2-Sirt3 axis might be used in a therapeutic strategy to fight chronic systemic inflammation and prevent the development of inflammation-linked diseases.

Imaging of the brain-heart axis: prognostic value in a European setting.

BACKGROUND AND AIMS: Increasing data suggest that stress-related neural activity (SNA) is associated with subsequent major adverse cardiovascular events (MACE) and may represent a therapeutic target. Current evidence is exclusively based on populations from the U.S. and Asia where limited information about cardiovascular disease risk was available. This study sought to investigate whether SNA imaging has clinical value in a well-characterized cohort of cardiovascular patients in Europe. METHODS: In this single-centre study, a total of 963 patients (mean age 58.4 ± 16.1 years, 40.7% female) with known cardiovascular status, ranging from 'at-risk' to manifest disease, and without active cancer underwent 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography between 1 January 2005 and 31 August 2019. Stress-related neural activity was assessed with validated methods and relations between SNA and MACE (non-fatal stroke, non-fatal myocardial infarction, coronary revascularization, and cardiovascular death) or all-cause mortality by time-to-event analysis. RESULTS: Over a maximum follow-up of 17 years, 118 individuals (12.3%) experienced MACE, and 270 (28.0%) died. In univariate analyses, SNA significantly correlated with an increased risk of MACE (sub-distribution hazard ratio 1.52, 95% CI 1.05-2.19; P = .026) or death (hazard ratio 2.49, 95% CI 1.96-3.17; P < .001). In multivariable analyses, the association between SNA imaging and MACE was lost when details of the cardiovascular status were added to the models. Conversely, the relationship between SNA imaging and all-cause mortality persisted after multivariable adjustments. CONCLUSIONS: In a European patient cohort where cardiovascular status is known, SNA imaging is a robust and independent predictor of all-cause mortality, but its prognostic value for MACE is less evident. Further studies should define specific patient populations that might profit from SNA imaging.

Sex differences and estrogen effects in cardiac mitochondria in human aortic stenosis and in the mouse heart.

Introduction: Sex differences in the adaptation to pressure overload have been described in humans, as well as animal models, and have been related to sex-specific expression of mitochondrial genes. We therefore tested whether sex differences in cardiac mitochondrial respiration exist in humans with aortic stenosis (AS). We also examined whether these potential differences may be at least partially due to sex hormones by testing if mitochondrial respiration is affected by estrogen (17ß-estradiol (E2)). Methods: Consecutive patients undergoing transapical aortic valve implantation (TAVI) (women, n = 7; men, n = 10) were included. Cardiac biopsies were obtained during TAVI and used directly for mitochondrial function measurements. Male and female C57BL/6J mice (n = 8/group) underwent sham surgery or gonadectomy (GDX) at the age of 2 months. After 14 days, mice were treated once with intraperitoneally injected vehicle (placebo), 17ß-estradiol (E2), estrogen receptor alpha (ERα) agonist [propyl pyrazole triol (PPT)], or ER beta (ERß) agonist (BAY-1214257). Thereafter, mitochondrial measurements were performed directly in cardiac skinned fibers from isolated left ventricles and musculus solei. Results: Mitochondrial State-3 respiration was higher in female than that in male human heart biopsies (15.0 ± 2.30 vs. 10.3 ± 2.05 nmol/mL/min/mg, p< 0.05). In the mouse model, mitochondrial State-3 respiration decreased significantly after GDX in female (27.6 ± 1.55 vs. 21.4 ± 1.71 nmol/mL/min/mg; p< 0.05) and male hearts (30.7 ± 1,48 vs. 23.7 ± 2,23 nmol/mL/min/mg; p< 0.05). In ovariectomized female mice, E2 and ERß-agonist treatment restored the State-3 respiration to intact placebo level, whereas ERα-agonist treatment did not modulate State-3 respiration. The treatment with E2, ERα-, or ERß-agonist did not modulate the State-3 respiration in GDX male mice. Conclusion: We identified sex differences in mitochondrial respiration in the diseased human heart. This is in alignment with known sex differences in the gene expression and proteome level at the functional level. E2 and ERß affect cardiac mitochondrial function in the mouse model, suggesting that they may also contribute to the sex differences in the human heart. Their roles should be further investigated.

Cardiovascular health-related quality of life in cancer: a prospective study comparing the ESC HeartQoL and EORTC QLQ-C30 questionnaire.

AIMS: Health-related quality of life (HRQoL) is highly relevant in cancer and often assessed with the EORTC QLQ-C30. Cardiovascular HRQoL in cancer can be measured with the ESC HeartQoL questionnaire. We compared these instruments and examined their prognostic value. METHODS AND RESULTS: Summary scores for EORTC QLQ-C30 (0-100 points) and ESC HeartQoL (0-3 points) questionnaires were prospectively assessed in 290 patients with mostly advanced cancer (stage 3/4: 81%, 1-year mortality: 36%) and 50 healthy controls (similar age and sex). Additionally, physical function and activity assessments were performed. Both questionnaires demonstrated reduced HRQoL in patients with cancer versus controls (EORTC QLQ-C30: 67 ± 20 vs. 91 ± 11, p < 0.001; ESC HeartQoL: 1.8 ± 0.8 vs. 2.7 ± 0.4, p < 0.001). The instruments were strongly correlated with each other (summary scores [r = 0.76], physical [r = 0.81], and emotional subscales [r = 0.75, all p < 0.001]) and independently associated with all-cause mortality (best cut-offs: EORTC QLQ-C30 <82.69: hazard ratio [HR] 2.33, p = 0.004; ESC HeartQoL <1.50: HR 1.85, p = 0.004 - adjusted for sex, age, left ventricular ejection fraction, N-terminal pro-B-type natriuretic peptide [NT-proBNP], high-sensitivity troponin T, cancer stage/type), with no differences in the strength of the association by sex (p-interaction > 0.9). Combining both questionnaires identified three risk groups with highest mortality in patients below both cut-offs (vs. patients above both cut-offs: HR 3.60, p < 0.001). Patients with results below both cut-offs, showed higher NT-proBNP and reduced physical function and activity. CONCLUSIONS: The EORTC QLQ-C30 and ESC HeartQoL - assessing cancer and cardiovascular HRQoL - are both associated with increased mortality in cancer patients, with even greater stratification by combing both. Reduced HRQoL scores were associated with elevated cardiovascular biomarkers and decreased functional status.

Sex hormones in SARS-CoV-2 susceptibility: key players or confounders?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a clear sex disparity in clinical outcomes. Hence, the interaction between sex hormones, virus entry receptors and immune responses has attracted major interest as a target for the prevention and treatment of SARS-CoV-2 infections. This Review summarizes the current understanding of the roles of androgens, oestrogens and progesterone in the regulation of virus entry receptors and disease progression of coronavirus disease 2019 (COVID-19) as well as their therapeutic value. Although many experimental and clinical studies have analysed potential mechanisms by which female sex hormones might provide protection against SARS-CoV-2 infectivity, there is currently no clear evidence for a sex-specific expression of virus entry receptors. In addition, reports describing an influence of oestrogen, progesterone and androgens on the course of COVID-19 vary widely. Current data also do not support the administration of oestradiol in COVID-19. The conflicting evidence and lack of consensus results from a paucity of mechanistic studies and clinical trials reporting sex-disaggregated data. Further, the influence of variables beyond biological factors (sex), such as sociocultural factors (gender), on COVID-19 manifestations has not been investigated. Future research will have to fill this knowledge gap as the influence of sex and gender on COVID-19 will be essential to understanding and managing the long-term consequences of this pandemic.

Imaging of heart disease in women: review and case presentation.

Cardiovascular diseases (CVD) remain the leading cause of mortality worldwide. Although major diagnostic and therapeutic advances have significantly improved the prognosis of patients with CVD in the past decades, these advances have less benefited women than age-matched men. Noninvasive cardiac imaging plays a key role in the diagnosis of CVD. Despite shared imaging features and strategies between both sexes, there are critical sex disparities that warrant careful consideration, related to the selection of the most suited imaging techniques, to technical limitations, and to specific diseases that are overrepresented in the female population. Taking these sex disparities into consideration holds promise to improve management and alleviate the burden of CVD in women. In this review, we summarize the specific features of cardiac imaging in four of the most common presentations of CVD in the female population including coronary artery disease, heart failure, pregnancy complications, and heart disease in oncology, thereby highlighting contemporary strengths and limitations. We further propose diagnostic algorithms tailored to women that might help in selecting the most appropriate imaging modality.

Heart-brain interactions in cardiac and brain diseases: why sex matters.

Cardiovascular disease and brain disorders, such as depression and cognitive dysfunction, are highly prevalent conditions and are among the leading causes limiting patient's quality of life. A growing body of evidence has shown an intimate crosstalk between the heart and the brain, resulting from a complex network of several physiological and neurohumoral circuits. From a pathophysiological perspective, both organs share common risk factors, such as hypertension, diabetes, smoking or dyslipidaemia, and are similarly affected by systemic inflammation, atherosclerosis, and dysfunction of the neuroendocrine system. In addition, there is an increasing awareness that physiological interactions between the two organs play important roles in potentiating disease and that sex- and gender-related differences modify those interactions between the heart and the brain over the entire lifespan. The present review summarizes contemporary evidence of the effect of sex on heart-brain interactions and how these influence pathogenesis, clinical manifestation, and treatment responses of specific heart and brain diseases.

Immunoreactivity of the SARS-CoV-2 entry proteins ACE-2 and TMPRSS-2 in murine models of hormonal manipulation, ageing, and cardiac injury.

Previous work indicates that SARS-CoV-2 virus entry proteins angiotensin-converting enzyme 2 (ACE-2) and the cell surface transmembrane protease serine 2 (TMPRSS-2) are regulated by sex hormones. However, clinical studies addressing this association have yielded conflicting results. We sought to analyze the impact of sex hormones, age, and cardiovascular disease on ACE-2 and TMPRSS-2 expression in different mouse models. ACE-2 and TMPRSS-2 expression was analyzed by immunostaining in a variety of tissues obtained from FVB/N mice undergoing either gonadectomy or sham-surgery and being subjected to ischemia-reperfusion injury or transverse aortic constriction surgery. In lung tissues sex did not have a significant impact on the expression of ACE-2 and TMPRSS-2. On the contrary, following myocardial injury, female sex was associated to a lower expression of ACE-2 at the level of the kidney tubules. In addition, after myocardial injury, a significant correlation between younger age and higher expression of both ACE-2 and TMPRSS-2 was observed for lung alveoli and bronchioli, kidney tubules, and liver sinusoids. Our experimental data indicate that gonadal hormones and biological sex do not alter ACE-2 and TMPRSS-2 expression in the respiratory tract in mice, independent of disease state. Thus, sex differences in ACE-2 and TMPRSS-2 protein expression observed in mice may not explain the higher disease burden of COVID-19 among men.

Male Macrophages and Fibroblasts from C57/BL6J Mice Are More Susceptible to Inflammatory Stimuli.

Mounting evidence argues for the significant impact of sex in numerous cardiac pathologies, including myocarditis. Macrophage polarization and activation of cardiac fibroblasts play a key role in myocardial inflammation and remodeling. However, the role of sex in these processes is still poorly understood. In this study, we investigated sex-specific alterations in the polarization of murine bone marrow-derived macrophages (BMMs) and the polarization-related changes in fibroblast activation. Cultured male and female murine BMMs from C57/BL6J mice were polarized into M1 (LPS) and M2 (IL-4/IL-13) macrophages. Furthermore, male and female cardiac fibroblasts from C57/BL6J mice were activated with TNF-α, TGF-ß, or conditioned medium from M1 BMMs. We found a significant overexpression of M1 markers (c-fos, NFκB, TNF-α, and IL-1ß) and M2 markers (MCP-1 and YM1) in male but not female activated macrophages. In addition, the ROS levels were higher in M1 male BMMs, indicating a stronger polarization. Similarly, the pro-fibrotic markers TGF-ß and IL-1ß were expressed in activated cardiac male fibroblasts at a significantly higher level than in female fibroblasts. In conclusion, the present study provides strong evidence for the male-specific polarization of BMMs and activation of cardiac fibroblasts in an inflammatory environment. The data show an increased inflammatory response and tissue remodeling in male mice.

Perimenopause and Postmenopause - Diagnosis and Interventions. Guideline of the DGGG and OEGGG (S3-Level, AWMF Registry Number 015-062, September 2020).

Aim The aim of the interdisciplinary S3-guideline Perimenopause and Postmenopause - Diagnosis and Interventions is to provide help to physicians as they inform women about the physiological changes which occur at this stage of life and the treatment options. The guideline should serve as a basis for decisions taken during routine medical care. This short version lists the statements and recommendations given in the long version of the guideline together with the evidence levels, the level of recommendation, and the strength of consensus. Methods The statements and recommendations are largely based on methodologically high-quality publications. The literature was evaluated by experts and mandate holders using evidence-based medicine (EbM) criteria. The search for evidence was carried out by the Essen Research Institute for Medical Management (EsFoMed). To some extent, this guideline also draws on an evaluation of the evidence used in the NICE guideline on Menopause and the S3-guidelines of the AWMF and has adapted parts of these guidelines. Recommendations Recommendations are given for the following subjects: diagnosis and therapeutic interventions for perimenopausal and postmenopausal women, urogynecology, cardiovascular disease, osteoporosis, dementia, depression, mood swings, hormone therapy and cancer risk, as well as primary ovarian insufficiency.

Sex-Specific Differences of the Inflammatory State in Experimental Autoimmune Myocarditis.

Increasing evidence suggests male sex as a potential risk factor for a higher incidence of cardiac fibrosis, stronger cardiac inflammation, and dilated cardiomyopathy (DCM) in human myocarditis. Chronic activation of the immune response in myocarditis may trigger autoimmunity. The experimental autoimmune myocarditis (EAM) model has been well established for the study of autoimmune myocarditis, however the role of sex in this pathology has not been fully explored. In this study, we investigated sex differences in the inflammatory response in the EAM model. We analyzed the cardiac function, as well as the inflammatory stage and fibrosis formation in the heart of EAM male and female rats. 21 days after induction of EAM, male EAM rats showed a decreased ejection fraction, stroke volume and cardiac output, while females did not. A significantly elevated number of infiltrates was detected in myocardium in both sexes, indicating the activation of macrophages following EAM induction. The level of anti-inflammatory macrophages (CD68+ ArgI+) was only significantly increased in female hearts. The expression of Col3A1 and fibrosis formation were more prominent in males. Furthermore, prominent pro-inflammatory factors were increased only in male rats. These findings indicate sex-specific alterations in the inflammatory stage of EAM, with a pro-inflammatory phenotype appearing in males and an anti-inflammatory phenotype in females, which both significantly affect cardiac function in autoimmune myocarditis.

Risk stratification and management of women with cardiomyopathy/heart failure planning pregnancy or presenting during/after pregnancy: a position statement from the Heart Failure Association of the European Society of Cardiology Study Group on Peripartum Cardiomyopathy.

This position paper focusses on the pathophysiology, diagnosis and management of women diagnosed with a cardiomyopathy, or at risk of heart failure (HF), who are planning to conceive or present with (de novo or previously unknown) HF during or after pregnancy. This includes the heterogeneous group of heart muscle diseases such as hypertrophic, dilated, arrhythmogenic right ventricular and non-classified cardiomyopathies, left ventricular non-compaction, peripartum cardiomyopathy, Takotsubo syndrome, adult congenital heart disease with HF, and patients with right HF. Also, patients with a history of chemo-/radiotherapy for cancer or haematological malignancies need specific pre-, during and post-pregnancy assessment and counselling. We summarize the current knowledge about pathophysiological mechanisms, including gene mutations, clinical presentation, diagnosis, and medical and device management, as well as risk stratification. Women with a known diagnosis of a cardiomyopathy will often require continuation of drug therapy, which has the potential to exert negative effects on the foetus. This position paper assists in balancing benefits and detrimental effects.

Sex differences in arterial wave reflection and the role of exogenous and endogenous sex hormones: results of the Berlin Aging Study II.

BACKGROUND: Arterial stiffness is tightly linked to hypertension. Sex differences in hypertension and arterial stiffness have already been established, yet the role of sex hormones is not precisely defined. This study examined age and sex differences of arterial wave reflection and associations with endogenous and exogenous sex hormones in women. METHODS: Pulse wave analysis was performed with an oscillometric device in 590 male and 400 female participants of the Berlin Aging Study II. Participants have been recruited from two age-strata, 22-35 years and 60-82 years. Data on exposures and potential confounders, including medication, have been collected at baseline visit. RESULTS: Aumentation index (AIx) and pulse wave velocity increased with age. Mean AIx was higher in women than in men. Multivariable regression analysis showed a positive association between use of oral contraceptive pills (OCPs) and AIx controlling for confounders (age, BMI, current smoking, central blood pressure), with a significantly higher mean AIx in OCP-users compared with nonusers (mean group difference: 4.41; 95% confidence interval 1.61-7.22). Per quartile decrease in estradiol level AIx increased by 1.72 (95% confidence interval 0.43-3.00). In OCP users endogenous estradiol was largely suppressed. CONCLUSION: The findings suggest important sex differences in measures of arterial wave reflection, with a higher mean AIx observed in women compared with men. OCPs may promote the development of hypertension by increasing AIx. Suppressed endogenous estradiol levels may be responsible for this increased wave reflection due to increased vasotonus of the small and medium arteries.

Sex and Gender Differences in Heart Failure.

Heart failure (HF) phenotypes differ according to sex. HF preserved ejection fraction (EF) has a greater prevalence in women and HF reduced EF (HFrEF) in men. Women with HF survive longer than men and have a lower risk of sudden death. Ischemia is the most prominent cause in men, whereas hypertension and diabetes contribute to a greater extent in women. Women with HF have a greater stiffness of the smaller left ventricle and a higher EF than men. This higher stiffness of women's hearts may be based on an increase in fibrosis at old age. In younger women estrogen reduces collagen production in female cardiac fibroblasts, but stimulates it in males. Lipid and energy metabolism is better maintained in female than in male stressed hearts. Pulse pressure is a key determinant of outcome in HF women but not in men. Takotsubo and peripartum cardiomyopathy are rare diseases affecting predominantly or exclusively women. Sudden cardiac arrest affects more men than women, but women are less adequately treated. New findings in HF therapy indicate that women with HFrEF need lower doses of beta-blockers and angiotensin-converting enzyme inhibitors than men for optimal effects. The combined neprilysin inhibitor/angiotensin II receptor blockers sacubitril-valsartan led to a significant reduction in event rate versus valsartan in women, which was not observed in men. Unfortunately, only less than 10% of recent randomized controlled trial report effects and adverse drug reactions for women and men separately. More research on sex differences in pathophysiology and therapy of HF is needed.

Regulation of AMPK activity by type 10 adenylyl cyclase: contribution to the mitochondrial biology, cellular redox and energy homeostasis.

The downregulation of AMP-activated protein kinase (AMPK) activity contributes to numerous pathologies. Recent reports suggest that the elevation of cellular cAMP promotes AMPK activity. However, the source of the cAMP pool that controls AMPK activity remains unknown. Mammalian cells possess two cAMP sources: membrane-bound adenylyl cyclase (tmAC) and intracellularly localized, type 10 soluble adenylyl cyclase (sAC). Due to the localization of sAC and AMPK in similar intracellular compartments, we hypothesized that sAC may control AMPK activity. In this study, sAC expression and activity were manipulated in H9C2 cells, adult rat cardiomyocytes or endothelial cells. sAC knockdown depleted the cellular cAMP content and decreased AMPK activity in an EPAC-dependent manner. Functionally, sAC knockdown reduced cellular ATP content, increased mitochondrial ROS formation and led to mitochondrial depolarization. Furthermore, sAC downregulation led to EPAC-dependent mitophagy disturbance, indicated by an increased mitochondrial mass and unaffected mitochondrial biogenesis. Consistently, sAC overexpression or stimulation with bicarbonate significantly increased AMPK activity and cellular ATP content. In contrast, tmAC inhibition or stimulation produced no effect on AMPK activity. Therefore, the sAC-EPAC axis may regulate basal and induced AMPK activity and support mitophagy, cellular energy and redox homeostasis. The study argues for sAC as a potential target in treating pathologies associated with AMPK downregulation.

Ninjurin1 regulates striated muscle growth and differentiation.

Chronic pressure overload due to aortic valve stenosis leads to pathological cardiac hypertrophy and heart failure. Hypertrophy is accompanied by an increase in myocyte surface area, which requires a proportional increase in the number of cell-cell and cell-matrix contacts to withstand enhanced workload. In a proteomic analysis we identified nerve injury-induced protein 1 (Ninjurin1), a 16kDa transmembrane cell-surface protein involved in cell adhesion and nerve repair, to be increased in hypertrophic hearts from patients with aortic stenosis. We hypothesised that Ninjurin1 is involved in myocyte hypertrophy. We analyzed cardiac biopsies from aortic-stenosis patients and control patients undergoing elective heart surgery. We studied cardiac hypertrophy in mice after transverse aortic constriction and angiotensin II infusions, and performed mechanistic analyses in cultured myocytes. We assessed the physiological role of ninjurin1 in zebrafish during heart and skeletal muscle development. Ninjurin1 was increased in hearts of aortic stenosis patients, compared to controls, as well as in hearts from mice with cardiac hypertrophy. Besides the 16kDa Ninjurin1 (Ninjurin1-16) we detected a 24kDa variant of Ninjurin1 (Ninjurin1-24), which was predominantly expressed during myocyte hypertrophy. We disclosed that the higher molecular weight of Ninjurin1-24 was caused by N-glycosylation. Ninjurin1-16 was contained in the cytoplasm of myocytes where it colocalized with stress-fibers. In contrast, Ninjurin1-24 was localized at myocyte membranes. Gain and loss-of-function experiments showed that Ninjurin1-24 plays a role in myocyte hypertrophy and myogenic differentiation in vitro. Reduced levels of ninjurin1 impaired cardiac and skeletal muscle development in zebrafish. We conclude that Ninjurin1 contributes to myocyte growth and differentiation, and that these effects are mainly mediated by N-glycosylated Ninjurin1-24.

Sex-specific regulation of cardiac microRNAs targeting mitochondrial proteins in pressure overload.

BACKGROUND: Maladaptive remodeling in pressure overload (PO)-induced left ventricular hypertrophy (LVH) may lead to heart failure. Major sex differences have been reported in this process. The steroid hormone 17ß-estradiol, along with its receptors ERα and ERß, is thought to be crucial for sex differences and is expected to be protective, but this may not hold true for males. Increasing evidence demonstrates a major role for microRNAs (miRNAs) in PO-induced LVH. However, little is known about the effects of biological sex and ERß on cardiac miRNA regulation and downstream mitochondrial targets. We aimed at the analysis of proteins involved in mitochondrial metabolism testing the hypothesis that they are the target of sex-specific miRNA regulation. METHODS: We employed the transverse aortic constriction model in mice and assessed the levels of five mitochondrial proteins, i.e., Auh, Crat, Decr1, Hadha, and Ndufs4. RESULTS: We found a significant decrease of the mitochondrial proteins primarily in the male overloaded heart compared with the corresponding control group. Following computational analysis to identify miRNAs putatively targeting these proteins, our in vitro experiments employing miRNA mimics demonstrated the presence of functional target sites for miRNAs in the 3'-untranslated region of the messenger RNAs coding for these proteins. Next, we assessed the levels of the functionally validated miRNAs under PO and found that their expression was induced only in the male overloaded heart. In contrast, there was no significant effect on miRNA expression in male mice with deficient ERß. CONCLUSION: We put forward that the male-specific induction of miRNAs and corresponding downregulation of downstream protein targets involved in mitochondrial metabolism may contribute to sex-specific remodeling in PO-induced LVH.

Sex-specific regulation of collagen I and III expression by 17ß-Estradiol in cardiac fibroblasts: role of estrogen receptors.

Aims: Sex differences in cardiac fibrosis point to the regulatory role of 17ß-Estradiol (E2) in cardiac fibroblasts (CF). We, therefore, asked whether male and female CF in rodent and human models are differentially susceptible to E2, and whether this is related to sex-specific activation of estrogen receptor alpha (ERα) and beta (ERß). Methods and results: In female rat CF (rCF), 24 h E2-treatment (10-8 M) led to a significant down-regulation of collagen I and III expression, whereas both collagens were up-regulated in male rCF. E2-induced sex-specific collagen regulation was also detected in human CF, indicating that this regulation is conserved across species. Using specific ERα- and ERß-agonists (10-7 M) for 24 h, we identified ERα as repressive and ERß as inducing factor in female and male rCF, respectively. In addition, E2-induced ERα phosphorylation at Ser118 only in female rCF, whereas Ser105 phosphorylation of ERß was exclusively found in male rCF. Further, in female rCF we found both ER bound to the collagen I and III promoters using chromatin immunoprecipitation assays. In contrast, in male rCF only ERß bound to both promoters. In engineered connective tissues (ECT) from rCF, collagen I and III mRNA were down-regulated in female ECT and up-regulated in male ECT by E2. This was accompanied by an impaired condensation of female ECT, whereas male ECT showed an increased condensation and stiffness upon E2-treatment, analysed by rheological measurements. Finally, we confirmed the E2-effect on both collagens in an in vivo mouse model with ovariectomy for E2 depletion, E2 substitution, and pressure overload by transverse aortic constriction. Conclusion: The mechanism underlying the sex-specific regulation of collagen I and III in the heart appears to involve E2-mediated differential ERα and ERß signaling in CFs.

17ß-Estradiol reduces mitochondrial cAMP content and cytochrome oxidase activity in a phosphodiesterase 2-dependent manner.

BACKGROUND AND PURPOSE: Mitochondria possess their own source of cAMP, that is, soluble adenylyl cyclase (sAC). Activation or expression of mitochondrial sAC promotes mitochondrial function. Oestrogen receptor signalling plays an essential role in the regulation of mitochondrial function. Here we aimed to determine whether 17ß-estradiol may affect mitochondrial cAMP signalling. EXPERIMENTAL APPROACH: Expression of the intra-mitochondrial proteins (Western blot), mitochondrial cAMP content (FRET-based live imaging and MS assay), mitochondrial membrane potential and cytochrome oxidase activity were analysed in H9C2 and C2C12 cells. KEY RESULTS: A 24 h treatment with 17ß-estradiol significantly reduced the basal level of mitochondrial cAMP, without affecting the intra-mitochondrial content of sAC, phosphodiesterase 2 (PDE2) or PKA and the activity of the intra-mitochondrial sAC. The effect of 17ß-estradiol on mitochondrial cAMP was prevented by inhibition of a cGMP-activated PDE2 or soluble guanylyl cyclase (sGC), suggesting a role of NO signalling. Indeed, 17ß-estradiol raised cellular levels of cGMP and the intra-mitochondrial expression of the catalytic subunit ß of sGC was found. The 17ß-estradiol-induced reduction of the mitochondrial cAMP level was accompanied by decreased cytochrome oxidase activity and mitochondrial membrane potential in a PDE2-dependent manner. CONCLUSIONS AND IMPLICATIONS: 17ß-estradiol reduced the basal level of mitochondrial cAMP content and cytochrome oxidase activity in a sAC-independent but in a PDE2-dependent manner. The results suggest a role of 17ß-estradiol-induced activation of NO signalling in the regulation of mitochondrial cAMP content. Our study adds a new aspect to the complex action of oestrogens on mitochondrial biology, that is relevant to hormone replacement therapy.

Gynecological Practice Represents the Ideal Setting for Early Opportunistic Cardiovascular Prevention: A Cross-Sectional Survey in an Urban Female Population.

BACKGROUND: Cardiovascular diseases are the main cause of mortality for women worldwide, yet their impact is frequently underestimated. To raise awareness for preventative lifestyle measures other contacts with the healthcare system should be exploited. We analyzed access patterns to other healthcare specialists and population screening measures to identify options for opportunistic counseling on cardiovascular risk. MATERIALS AND METHODS: We enrolled 1062 randomly selected German urban women aged 25-74 years in 2012-2013, divided into 5 age bands. Women were asked about sociodemographic characteristics, clinical and gynecological history, physician attendance patterns, screening behavior and primary sources of health and preventative information, and clinical examination attendance. RESULTS: Obstetrician/gynecologists (OBGYN) were the most frequently consulted physicians within the last 12 months (75.3%), more than general practitioners (GP; 74%). Attendance rates to OBGYNs were not affected by education or income, solely a body mass index (BMI) >30 associated with significantly reduced rates of attendance (OR = 0.4, CI 95% = 0.17-0.78, p = 0.009). Women with low to medium Framingham risk scores were more likely to attend an OBGYN than a GP if they attended only one specialist. Attendance of population screening measures is limited (<60% for all offers) and hence unsuitable for systematic cardiovascular counseling. CONCLUSION: OBGYN represent a very popular and equitable healthcare contact for women of all ages and this could be exploited for cardiovascular screening. Furthermore, the strikingly different sources of health information reported highlight a need for improved health communication and differentiation of messages.