Estrogen receptor beta signals to inhibition of cardiac fibrosis

Genistein alleviates pulmonary fibrosis by inactivating lung fibroblasts

Pulmonary fibrosis is a serious lung disease that occurs predominantly in men. Genistein is an important natural soybeanderived phytoestrogen that affects various biological functions, such as cell migration and fibrosis. However, the antifibrotic effects of genistein on pulmonary fibrosis are largely unknown. The antifibrotic effects of genistein were evaluated using in vitro and in vivo models of lung fibrosis. Proteomic data were analyzed using nano-LC-ESI-MS/MS. Genistein significantly reduced transforming growth factor (TGF)-β1-induced expression of collagen type I and α-smooth muscle actin (SMA) in MRC-5 cells and primary fibroblasts from patients with idiopathic pulmonary fibrosis (IPF). Genistein also reduced TGF-β1-induced expression of p-Smad2/3 and p-p38 MAPK in fibroblast models. Comprehensive protein analysis confirmed that genistein exerted an anti-fibrotic effect by regulating various molecular mechanisms, such as unfolded protein response, epithelial mesenchymal transition (EMT), mammalian target of rapamycin complex 1 (mTORC1) signaling, cell death, and several metabolic pathways. Genistein was also found to decrease hydroxyproline levels in the lungs of BLM-treated mice. Genistein exerted an anti-fibrotic effect by preventing fibroblast activation, suggesting that genistein could be developed as a pharmacological agent for the prevention and treatment of pulmonary fibrosis. [BMB Reports 2024; 57(3): 143-148].

Interstitial Fibrosis and Arrhythmic Mitral Valve Prolapse: Unravelling Sex-Based Differences

Background

Interstitial fibrosis as quantified by cardiac magnetic resonance (CMR) has been demonstrated in arrhythmic mitral valve prolapse (MVP), a condition with known female predominance. However, prior studies included only MVP cases with significant mitral regurgitation (MR) or mitral annular disjunction (MAD). We sought to evaluate the association between interstitial fibrosis and complex ventricular ectopy (ComVE) in MVPs unselected for MAD or severe MR, and to investigate the contribution of sex to this association.

Methods

We performed contrast CMR in consecutive individuals with MVP between 2020 and 2022. Extracellular volume fraction (ECV%), a surrogate marker for interstitial fibrosis, was quantified using T 1 mapping. Replacement fibrosis was assessed using late gadolinium enhancement (LGE). ComVE, defined as frequent premature ventricular contractions and/or non-sustained/sustained ventricular tachycardia (VT), was detected using ambulatory ECG monitoring.

Results

We identified 59 MVP cases without severe MR (49% women, 80% with mild or less MR) and available ECV% measurement. Among these, 23 (39%) had ComVE, including a case of aborted ventricular fibrillation (VF) and one with sudden arrhythmic death, both females. Global ECV% was significantly greater in ComVE versus non-ComVE (31%[27-33] vs 27%[23-30], p=0.002). In MVP-ComVE, higher segmental ECV% was not limited to the inferolateral/inferior LV wall, but was also demonstrated in atypical segments including the anterior/anterolateral wall (p<0.05). The association between ComVE and ECV% was driven by female sex (32%[30-33] vs 28%[26-30], p=0.003 in females; 31%[25-33] vs 26%[23-30], p=0.22 in males). ECV% remained independently associated with an increased risk of ComVE, including VT/VF, after adjustment for cardiovascular risk factors, MAD, and LGE (p<0.01).

Conclusion

In MVP without significant MR, interstitial fibrosis by CMR is associated with an increased risk of ComVE, suggesting a primary myopathic process. The stronger association between interstitial fibrosis and ComVE in females may explain why severe arrhythmic complications are more prevalent among women.

Abstract Figure

Effects of aging and endurance exercise training on cardiorespiratory fitness and cardiac structure and function in healthy midlife and older women

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in women in developed societies. Unfavorable structural and functional adaptations within the heart and central blood vessels with sedentary aging in women can act as the substrate for the development of debilitating CVD conditions such as heart failure with preserved ejection fraction (HFpEF). The large decline in cardiorespiratory fitness, as indicated by maximal or peak oxygen uptake (V̇o2max and V̇o2peak, respectively), that occurs in women as they age significantly affects their health and chronic disease status, as well as the risk of cardiovascular and all-cause mortality. Midlife and older women who have performed structured endurance exercise training for several years or decades of their adult lives exhibit a V̇o2max and cardiac and vascular structure and function that are on par or even superior to much younger sedentary women. Therefore, regular endurance exercise training appears to be an effective preventative strategy for mitigating the adverse physiological cardiovascular adaptations associated with sedentary aging in women. Herein, we narratively describe the aging and short- and long-term endurance exercise training adaptations in V̇o2max, cardiac structure, and left ventricular systolic and diastolic function at rest and exercise in midlife and older women. The role of circulating estrogens on cardiac structure and function is described for consideration in the timing of exercise interventions to maximize beneficial adaptations. Current research gaps and potential areas for future investigation to advance our understanding in this critical knowledge area are highlighted.

Low-dose Bisphenol A exposure alters the functionality and cellular environment in a human cardiomyocyte model

Early embryonic development represents a sensitive time-window during which the foetus might be vulnerable to the exposure of environmental contaminants, potentially leading to heart diseases also later in life. Bisphenol A (BPA), a synthetic chemical widely used in plastics manufacturing, has been associated with heart developmental defects, even in low concentrations. This study aims to investigate the effects of environmentally relevant doses of BPA on developing cardiomyocytes using a human induced pluripotent stem cell (hiPSC)-derived model. Firstly, a 2D in vitro differentiation system to obtain cardiomyocytes from hiPSCs (hiPSC-CMs) have been established and characterised to provide a suitable model for the early stages of cardiac development. Then, the effects of a repeated BPA exposure, starting from the undifferentiated stage throughout the differentiation process, were evaluated. The chemical significantly decreased the beat rate of hiPSC-CMs, extending the contraction and relaxation time in a dose-dependent manner. Quantitative proteomics analysis revealed a high abundance of basement membrane (BM) components (e.g., COL4A1, COL4A2, LAMC1, NID2) and a significant increase in TNNC1 and SERBP1 proteins in hiPSC-CMs treated with BPA. Network analysis of proteomics data supported altered extracellular matrix remodelling and provided a disease-gene association with well-known pathological conditions of the heart. Furthermore, upon hypoxia-reoxygenation challenge, hiPSC-CMs treated with BPA showed higher rate of apoptotic events. Taken together, our results revealed that a long-term treatment, even with low doses of BPA, interferes with hiPSC-CMs functionality and alters the surrounding cellular environment, providing new insights about diseases that might arise upon the toxin exposure. Our study contributes to the current understanding of BPA effects on developing human foetal cardiomyocytes, in correlation with human clinical observations and animal studies, and it provides a suitable model for New Approach Methodologies (NAMs) for environmental chemical hazard and risk assessment.

Computational screen for sex-specific drug effects in a cardiac fibroblast signaling network model

Heart disease is the leading cause of death in both men and women. Cardiac fibrosis is the uncontrolled accumulation of extracellular matrix proteins, which can exacerbate the progression of heart failure, and there are currently no drugs approved specifically to target matrix accumulation in the heart. Computational signaling network models (SNMs) can be used to facilitate discovery of novel drug targets. However, the vast majority of SNMs are not sex-specific and/or are developed and validated using data skewed towards male in vitro and in vivo samples. Biological sex is an important consideration in cardiovascular health and drug development. In this study, we integrate a cardiac fibroblast SNM with estrogen signaling pathways to create sex-specific SNMs. The sex-specific SNMs demonstrated high validation accuracy compared to in vitro experimental studies in the literature while also elucidating how estrogen signaling can modulate the effect of fibrotic cytokines via multi-pathway interactions. Further, perturbation analysis and drug screening uncovered several drug compounds predicted to generate divergent fibrotic responses in male vs. female conditions, which warrant further study in the pursuit of sex-specific treatment recommendations for cardiac fibrosis. Future model development and validation will require more generation of sex-specific data to further enhance modeling capabilities for clinically relevant sex-specific predictions of cardiac fibrosis and treatment.

Computational Screen for Sex-Specific Drug Effects in a Cardiac Fibroblast Network Model

Heart disease is the leading cause of death in both men and women. Cardiac fibrosis is the uncontrolled accumulation of extracellular matrix proteins which can exacerbate the progression of heart failure, and there are currently no drugs approved specifically to target matrix accumulation in the heart. Computational signaling network models (SNMs) can be used to facilitate discovery of novel drug targets. However, the vast majority of SNMs are not sex-specific and/or are developed and validated using data skewed towards male in vitro and in vivo samples. Biological sex is an important consideration in cardiovascular health and drug development. In this study, we integrate a previously constructed cardiac fibroblast SNM with estrogen signaling pathways to create sex-specific SNMs. The sex-specific SNMs maintained previously high validation when compared to in vitro experimental studies in the literature. A sex-specific perturbation analysis and drug screen uncovered several potential pathways that warrant further study in the pursuit of sex-specific treatment recommendations for cardiac fibrosis.

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.

Membrane Estrogen Receptor β Is Sufficient to Mitigate Cardiac Cell Pathology

Estrogen acting through estrogen receptor β (ERβ) has been shown to oppose the stimulation of cardiac myocytes and cardiac fibroblasts that results in cardiac hypertrophy and fibrosis. Previous work has implicated signal transduction from ERβ as being important to the function of estrogen in this regard. Here we address whether membrane ERβ is sufficient to oppose key mechanisms by which angiotensin II (AngII) stimulates cardiac cell pathology. To do this we first defined essential structural elements within ERβ that are necessary for membrane or nuclear localization in cells. We previously determined that cysteine 418 is the site of palmitoylation of ERβ that is required and sufficient for cell membrane localization in mice and is the same site in humans. Here we determined in Chinese hamster ovarian (CHO) cells, and mouse and rat myocytes and cardiac fibroblasts, the effect on multiple aspects of signal transduction by expressing wild-type (WT ) or a C418A-mutant ERβ. To test the importance of the nuclear receptor, we determined a 4-amino acid deletion in the E domain of ERβ that strongly blocked nuclear localization. Using these tools, we expressed WT and mutant ERβ constructs into cardiomyocytes and cardiac fibroblasts from ERβ-deleted mice. We determined the ability of estrogen to mitigate cell pathology stimulated by AngII and whether the membrane ERβ is necessary and sufficient.

A multi-tissue transcriptomic landscape of female mice in estrus and diestrus provides clues for precision medicine

Female reproductive cycle, also known as menstrual cycle or estrous cycle in primate or non-primate mammals, respectively, dominates the reproductive processes in non-pregnant state. However, in addition to reproductive tissues, reproductive cycle could also perform global regulation because the receptors of two major female hormones fluctuating throughout the cycle, estrogen and progesterone, are widely distributed. Therefore, a multi-tissue gene expression landscape is in continuous demand for better understanding the systemic changes during the reproductive cycle but remains largely undefined. Here we delineated a transcriptomic landscape covering 15 tissues of C57BL/6J female mice in two phases of estrous cycle, estrus and diestrus, by RNA-sequencing. Then, a number of genes, pathways, and transcription factors involved in the estrous cycle were revealed. We found the estrous cycle could widely regulate the neuro-functions, immuno-functions, blood coagulation and so on. And behind the transcriptomic alteration between estrus and diestrus, 13 transcription factors may play important roles. Next, bioinformatics modeling with 1,263 manually curated gene signatures of various physiological and pathophysiological states systematically characterized the beneficial/deleterious effects brought by estrus/diestrus on individual tissues. We revealed that the estrous cycle has a significant effect on cardiovascular system (aorta, heart, vein), in which the anti-hypertensive pattern in aorta induced by estrus is one of the most striking findings. Inspired by this point, we validated that two hypotensive drugs, felodipine and acebutolol, could exhibit significantly enhanced efficacy in estrus than diestrus by mouse and rat experiments. Together, this study provides a valuable data resource for investigating reproductive cycle from a transcriptomic perspective, and presents models and clues for investigating precision medicine associated with reproductive cycle.

Heart Failure in Menopause: Treatment and New Approaches

Aging is an important risk factor for the development of heart failure (HF) and half of patients with HF have preserved ejection fraction (HFpEF) which is more common in elderly women. In general, sex differences that lead to discrepancies in risk factors and to the development of cardiovascular disease (CVD) have been attributed to the reduced level of circulating estrogen during menopause. Estrogen receptors adaptively modulate fibrotic, apoptotic, inflammatory processes and calcium homeostasis, factors that are directly involved in the HFpEF. Therefore, during menopause, estrogen depletion reduces the cardioprotection. Preclinical menopause models demonstrated that several signaling pathways and organ systems are closely involved in the development of HFpEF, including dysregulation of the renin-angiotensin system (RAS), chronic inflammatory process and alteration in the sympathetic nervous system. Thus, this review explores thealterations observed in the condition of HFpEF induced by menopause and the therapeutic targets with potential to interfere with the disease progress.

Membrane-Initiated Estrogen, Androgen, and Progesterone Receptor Signaling in Health and Disease

Rapid effects of steroid hormones were discovered in the early 1950s, but the subject was dominated in the 1970s by discoveries of estradiol and progesterone stimulating protein synthesis. This led to the paradigm that steroid hormones regulate growth, differentiation, and metabolism via binding a receptor in the nucleus. It took 30 years to appreciate not only that some cellular functions arise solely from membrane-localized steroid receptor (SR) actions, but that rapid sex steroid signaling from membrane-localized SRs is a prerequisite for the phosphorylation, nuclear import, and potentiation of the transcriptional activity of nuclear SR counterparts. Here, we provide a review and update on the current state of knowledge of membrane-initiated estrogen (ER), androgen (AR) and progesterone (PR) receptor signaling, the mechanisms of membrane-associated SR potentiation of their nuclear SR homologues, and the importance of this membrane-nuclear SR collaboration in physiology and disease. We also highlight potential clinical implications of pathway-selective modulation of membrane-associated SR.

Sex-Related Differences in Medically Treated Moderate Aortic Stenosis

Background

Recent data showed poor long-term survival in patients with moderate AS. Although sex differences in left ventricular (LV) remodeling and outcome are well described in severe AS, it has not been evaluated in moderate AS.

Methods

In this retrospective, multicenter study, patients with a first diagnosis of moderate AS diagnosed between 2001 and 2019 were identified. Clinical and echocardiographic parameters were recorded at baseline and compared between men and women. Patients were followed up for the primary endpoint of all-cause mortality with censoring at the time of aortic valve replacement.

Results

A total of 1895 patients with moderate AS (age 73 ± 10 years, 52% male) were included. Women showed more concentric hypertrophy and had more pronounced LV diastolic dysfunction than men. During a median follow-up of 34 (13-60) months, 682 (36%) deaths occurred. Men showed significantly higher mortality rates at 3- and 5-year follow-up (30% and 48%, respectively) than women (26% and 39%, respectively) (p = 0.011). On multivariable analysis, male sex remained independently associated with mortality (hazard ratio 1.209; 95% CI: 1.024-1.428; p = 0.025). LV remodeling (according to LV mass index) was associated with worse outcomes (hazard ratio 1.003; CI: 1.001-1.005; p = 0.006), but no association was observed between the interaction of LV mass index and sex with outcomes.

Conclusions

LV remodeling patterns are different between men and women having moderate AS. Male sex is associated with worse outcomes in patients with medically treated moderate AS. Further studies investigating the management of moderate AS in a sex-specific manner are needed.

Role of estrogen receptors in health and disease

Estrogen receptors (ERs) regulate multiple complex physiological processes in humans. Abnormal ER signaling may result in various disorders, including reproductive system-related disorders (endometriosis, and breast, ovarian, and prostate cancer), bone-related abnormalities, lung cancer, cardiovascular disease, gastrointestinal disease, urogenital tract disease, neurodegenerative disorders, and cutaneous melanoma. ER alpha (ERα), ER beta (ERβ), and novel G-protein-coupled estrogen receptor 1 (GPER1) have been identified as the most prominent ERs. This review provides an overview of ERα, ERβ, and GPER1, as well as their functions in health and disease. Furthermore, the potential clinical applications and challenges are discussed.

A framework for developing sex-specific engineered heart models

The convergence of tissue engineering and patient-specific stem cell biology has enabled the engineering of in vitro tissue models that allow the study of patient-tailored treatment modalities. However, sex-related disparities in health and disease, from systemic hormonal influences to cellular-level differences, are often overlooked in stem cell biology, tissue engineering and preclinical screening. The cardiovascular system, in particular, shows considerable sex-related differences, which need to be considered in cardiac tissue engineering. In this Review, we analyse sex-related properties of the heart muscle in the context of health and disease, and discuss a framework for including sex-based differences in human cardiac tissue engineering. We highlight how sex-based features can be implemented at the cellular and tissue levels, and how sex-specific cardiac models could advance the study of cardiovascular diseases. Finally, we define design criteria for sex-specific cardiac tissue engineering and provide an outlook to future research possibilities beyond the cardiovascular system.

The association between estrogen receptor 2 gene polymorphism and complexity of coronary artery disease: an analysis in elective percutaneous coronary intervention patients

BACKGROUND

One of the most common causes of death in the world is coronary artery disease (CAD). Estrogen, the most important early sex hormones in women, plays an important role in the risk reduction of cardiovascular disease (CVD). Expression of estrogen as well as its receptors including estrogen receptor alpha (ER1) and estrogen receptor beta (ER2) might have an association with the severity or the complexity of CAD. Since most articles have focused on the relationship between ER1 gene polymorphism and CAD, in this study, we aimed to evaluate the association of two ER2 gene polymorphisms, rs4986938 (AluI) and rs1256049 (RsaI), with the severity of CAD.

METHODS

148 patients with confirmed CAD who underwent elective percutaneous coronary intervention (PCI) were included in this study. Blood samples were collected before coronary angiography and ER2 gene polymorphisms were analyzed by the PCR-RFLP method. The STNTAX Score (SS), grading system for CAD complexity, was evaluated by an interventional cardiologist who was blinded to other data.

RESULTS

110 men and 38 women were participated in this study. Our results revealed a statistically significant relationship between SS and rs4986938 polymorphism of ER2 in men. In contrast, there was no association between rs1256049 genotypes and SS after performing regression analysis.

CONCLUSIONS

Besides to the estrogen level, the genetic variation of its receptors might play an important role in the severity or the complexity of CAD. According to our results, rs4986938 polymorphism of ER2 gene may assert a pivotal role in the severity of CAD in men; however, this assumption needs to be proved in studies with a larger population.

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.

Cyanide Poisoning Compromises Gene Pathways Modulating Cardiac Injury in Vivo

Smoke inhalation from a structure fire is a common route of cyanide poisoning in the U.S. Cyanide inhibits cellular respiration, often leading to death. Its rapid distribution throughout the body can result in injuries to multiple organs, and cyanide victims were reported to experience myocardial infarction and other cardiac complications. However, molecular mechanisms of such complications are yet to be elucidated. While FDA-approved CN antidotes such as sodium thiosulfate and hydroxocobalamin are clinically used, they have foreseeable limitations during mass casualty situations because they require intravenous administration. To facilitate the development of better antidotes and therapeutic treatments, a global view of molecular changes induced by cyanide exposure is necessary. As an exploratory pursuit, we performed oligonucleotide microarrays to establish cardiac transcriptomes of an animal model of nose-only inhalation exposure to hydrogen cyanide (HCN), which is relevant to smoke inhalation. We also profiled cardiac transcriptomes after subcutaneous injection of potassium cyanide (KCN). Although the KCN injection model has often been used to evaluate medical countermeasures, this study demonstrated that cardiac transcriptomes are largely different from that of the HCN inhalation model at multiple time points within 24 h after exposure. Pathway analysis identified that HCN-induced transcriptomes were enriched with genes encoding mediators of pathways critical in modulation of cardiac complications and that a large number of such genes were significantly decreased in expression. We utilized the upstream regulatory analysis to propose drugs that can be potentially employed to treat cyanide-induced cardiac complications.

Estrogen Receptors: Therapeutic Perspectives for the Treatment of Cardiac Dysfunction after Myocardial Infarction

Estrogen receptors (ER) mediate functions beyond their endocrine roles, as modulation of cardiovascular, renal, and immune systems through anti-inflammatory and anti-apoptotic effects, preventing necrosis of cardiomyocytes and endothelial cells, and attenuating cardiac hypertrophy. Estradiol (E2) prevents cardiac dysfunction, increases nitric oxide synthesis, and reduces the proliferation of vascular cells, yielding protective effects, regardless of gender. Such actions are mediated by ER (ER-alpha (ERα), ER-beta (ERβ), or G protein-coupled ER (GPER)) through genomic or non-genomic pathways, which regulate cardiovascular function and prevent tissue remodeling. Despite the extensive knowledge on the cardioprotective effects of estrogen, clinical studies conducted on myocardial infarction (MI) and cardiovascular diseases still include favorable and unfavorable profiles. The purpose of this review is to provide up-to-date information regarding molecular, preclinical, and clinical aspects of cardiovascular E2 effects and ER modulation as a potential therapeutic target for the treatment of MI-induced cardiac dysfunction.

The endocrinological component and signaling pathways associated to cardiac hypertrophy

Although myocardial growth corresponds to an adaptive response to maintain cardiac contractile function, the cardiac hypertrophy is a condition that occurs in many cardiovascular diseases and typically precedes the onset of heart failure. Different endocrine factors such as thyroid hormones, insulin, insulin-like growth factor 1 (IGF-1), angiotensin II (Ang II), endothelin (ET-1), catecholamines, estrogen, among others represent important stimuli to cardiomyocyte hypertrophy. Thus, numerous endocrine disorders manifested as changes in the local environment or multiple organ systems are especially important in the context of progression from cardiac hypertrophy to heart failure. Based on that information, this review summarizes experimental findings regarding the influence of such hormones upon signalling pathways associated with cardiac hypertrophy. Understanding mechanisms through which hormones differentially regulate cardiac hypertrophy could open ways to obtain therapeutic approaches that contribute to prevent or delay the onset of heart failure related to endocrine diseases.

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.

The Role of Estrogen Receptors in Cardiovascular Disease

Cardiovascular Diseases (CVDs) are the leading cause of death globally. More than 17 million people die worldwide from CVD per year. There is considerable evidence suggesting that estrogen modulates cardiovascular physiology and function in both health and disease, and that it could potentially serve as a cardioprotective agent. The effects of estrogen on cardiovascular function are mediated by nuclear and membrane estrogen receptors (ERs), including estrogen receptor alpha (ERα), estrogen receptor beta (ERβ), and G-protein-coupled ER (GPR30 or GPER). Receptor binding in turn confers pleiotropic effects through both genomic and non-genomic signaling to maintain cardiovascular homeostasis. Each ER has been implicated in multiple pre-clinical cardiovascular disease models. This review will discuss current reports on the underlying molecular mechanisms of the ERs in regulating vascular pathology, with a special emphasis on hypertension, pulmonary hypertension, and atherosclerosis, as well as in regulating cardiac pathology, with a particular emphasis on ischemia/reperfusion injury, heart failure with reduced ejection fraction, and heart failure with preserved ejection fraction.

Non-ischemic dilated cardiomyopathy and cardiac fibrosis

Cardiac fibrosis is associated with non-ischemic dilated cardiomyopathy, increasing its morbidity and mortality. Cardiac fibroblast is the keystone of fibrogenesis, being activated by numerous cellular and humoral factors. Macrophages, CD4+ and CD8+ T cells, mast cells, and endothelial cells stimulate fibrogenesis directly by activating cardiac fibroblasts and indirectly by synthetizing various profibrotic molecules. The synthesis of type 1 and type 3 collagen, fibronectin, and α-smooth muscle actin is rendered by various mechanisms like transforming growth factor-beta/small mothers against decapentaplegic pathway, renin angiotensin system, and estrogens, which in turn alter the extracellular matrix. Investigating the underlying mechanisms will allow the development of diagnostic and prognostic tools and discover novel specific therapies. Serum biomarkers aid in the diagnosis and tracking of cardiac fibrosis progression. The diagnostic gold standard is cardiac magnetic resonance with gadolinium administration that allows quantification of cardiac fibrosis either by late gadolinium enhancement assessment or by T1 mapping. Therefore, the goal is to stop and even reverse cardiac fibrosis by developing specific therapies that directly target fibrogenesis, in addition to the drugs used to treat heart failure. Cardiac resynchronization therapy had shown to revert myocardial remodeling and to reduce cardiac fibrosis. The purpose of this review is to provide an overview of currently available data.

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

Aims

Sex differences in cardiac fibrosis point to the regulatory role of 17β-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 (ERβ).

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 ERβ-agonists (10-7 M) for 24 h, we identified ERα as repressive and ERβ 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 ERβ 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 ERβ 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 ERβ signaling in CFs.

Sex-Related Differences in the Extent of Myocardial Fibrosis in Patients With Aortic Valve Stenosis

OBJECTIVES

The aim of this study was to assess the effect of sex on myocardial fibrosis as assessed by using cardiac magnetic resonance (CMR) imaging in aortic stenosis (AS).

BACKGROUND

Previous studies reported sex-related differences in the left ventricular (LV) remodeling response to pressure overload in AS. However, there are very few data regarding the effect of sex on myocardial fibrosis, a key marker of LV decompensation and adverse cardiac events in AS.

METHODS

A total of 249 patients (mean age 66 ± 13 years; 30% women) with at least mild AS were recruited from 2 prospective observational cohort studies and underwent comprehensive Doppler echocardiography and CMR examinations. On CMR, T1 mapping was used to quantify extracellular volume (ECV) fraction as a marker of diffuse fibrosis, and late gadolinium enhancement (LGE) was used to assess focal fibrosis.

RESULTS

There was no difference in age between women and men (age 66 ± 15 years vs 66 ± 12 years; p = 0.78). However, women presented with a better cardiovascular risk profile than men with less hypertension, dyslipidemia, diabetes, and coronary artery disease (all, p ≤ 0.10). As expected, LV mass index measured by CMR imaging was smaller in women than in men (p < 0.0001). Despite fewer comorbidities, women presented with larger ECV fraction (median: 29.0% [25th to 75th percentiles: 27.4% to 30.6%] vs. 26.8% [25th to 75th percentiles: 25.1% to 28.7%]; p < 0.0001) and similar LGE (median: 4.5% [25th-75th percentiles: 2.3% to 7.0%] vs. 2.8% [25th-75th percentiles: 0.6% to 6.8%]; p = 0.20) than men. In multivariable analysis, female sex remained an independent determinant of higher ECV fraction and LGE (all, p ≤ 0.05).

CONCLUSIONS

Women have greater diffuse and focal myocardial fibrosis independent of the degree of AS severity. These findings further emphasize the sex-related differences in LV remodeling response to pressure overload.

Selected Sex Related Differences in Pathophysiology of Cardiovascular System

The annual incidence of cardiovascular diseases is age-dependently increasing both in men and women, however, the prevalence is higher in men until midlife. The higher incidence of cardiovascular disease in men than in women of similar age, and the menopause-associated increase in cardiovascular disease in women, has led to speculation that gender-related differences in sex hormones might have a key role in the development and evolution of cardiovascular disease. There are several suggested pathways in which gender and sex hormones can affect human cardiovascular system to produce original sexually different pathophysiology between women and men. Sex steroid hormones and their receptors are critical determinants of cardiovascular gender differences. Also arterial blood pressure is typically lower in women than in men what could be explained particularly by greater synthesis of nitric oxide (NO) in women. Female cardiomyocytes have a greater survival advantage when challenged with oxidative stress, suggesting that female hormones may play an important role in antioxidative protection of myocardium. It was also demonstrated in animal models that combination of XX chromosomes versus an XY chromosomes enhances sex differences in higher HDL cholesterol. Women were found to have reduced sympathetic activity (reflected by lower total peripheral resistance) and pulmonary artery pressure and enhanced parasympathetic activity relative to men. Similarly, men were found to have higher plasma norepinephrine levels than women. Regarding differences between the sexes in electrophysiology of the heart, two principle mechanisms have been proposed to explain them: hormonal effects on the expression or function of ion channels or, conversely, differences in autonomic tone. To improve diagnosis and treatment of cardiovascular diseases, greater focus on understanding the molecular and cellular physiology of the sex steroid hormones and their receptors in the cardiovascular system will be required.

Cardiac hypertrophy with obesity is augmented after pregnancy in C57BL/6 mice

BACKGROUND

Over a third of reproductive-age women in the USA are obese, and the prevalence of cardiovascular disease (CVD) is rising in premenopausal women. Cardiac hypertrophy is an independent predictor of CVD. In contrast to pregnancy, where transiently increased left ventricular (LV) mass is not associated with cardiac damage, obesity-mediated cardiac hypertrophy is pathological. There is a paucity of data describing the effect of obesity during pregnancy on maternal cardiovascular health. The purpose of this study was to determine the long-term effect of obesity during pregnancy on cardiac function and structure in mice.

METHODS

Female C57BL/6 J mice were fed a high-fat (HF) or a low-fat (LF) diet for 20 weeks. After 4 weeks, LF- and HF-fed female mice were either crossed with males to become pregnant or remained non-pregnant controls. Following delivery, pups were euthanized, and females maintained on respective diets. After 20 weeks of diet feeding, cardiac function was quantified by echocardiography, and plasma leptin and adiponectin concentrations quantified in LF- and HF-fed postpartum and nulliparous females. mRNA abundance of genes regulating cardiac hypertrophy and remodeling was quantified from left ventricles using the NanoString nCounter Analysis System. Cardiac fibrosis was assessed from picrosirius red staining of left ventricles.

RESULTS

HF-fed postpartum mice had markedly greater weight gain and fat mass expansion with obesity, associated with significantly increased LV mass, cardiac output, and stroke volume compared with HF-fed nulliparous mice. Plasma leptin, but not adiponectin, concentrations were correlated with LV mass in HF-fed females. HF feeding increased LV posterior wall thickness; however, LV chamber diameter was only increased in HF-fed postpartum females. Despite the marked increase in LV mass in HF-fed postpartum mice, mRNA abundance of genes regulating fibrosis and interstitial collagen content was similar between HF-fed nulliparous and postpartum mice. In contrast, only HF-fed postpartum mice exhibited altered expression of genes regulating the extracellular matrix.

CONCLUSIONS

These results suggest that the combined effects of pregnancy and obesity augment cardiac hypertrophy and promote remodeling. The rising prevalence of CVD in premenopausal women may be attributed to an increased prevalence of women entering pregnancy with an overweight or obese BMI.

MicroRNA let-7 Downregulates Ligand-Independent Estrogen Receptor-mediated Male-Predominant Pulmonary Fibrosis

Rationale: The relevance of hormones in idiopathic pulmonary fibrosis (IPF), a predominantly male lung disease, is unknown.Objectives: To determine whether the ER (estrogen receptor) facilitates the development of pulmonary fibrosis and is mediated in part through microRNA regulation of ERα and ERα-activated profibrotic pathways.Methods: ER expression in male lung tissue and myofibroblasts from control subjects (n = 6) and patients with IPF (n = 6), aging bleomycin (BLM)-treated mice (n = 7), and BLM-treated AF2ERKI mice (n = 7) was determined. MicroRNAs that regulate ER and fibrotic pathways were assessed. Transfections with a reporter plasmid containing the 3' untranslated region of the gene encoding ERα (ESR1) with and without miRNA let-7 mimics or inhibitors or an estrogen response element-driven reporter construct (ERE) construct were conducted.Measurements and Main Results: ERα expression increased in IPF lung tissue, myofibroblasts, or BLM mice. In vitro treatment with let-7 mimic transfections in human myofibroblasts reduced ERα expression and associated fibrotic pathways. AF2ERKI mice developed BLM-induced lung fibrosis, suggesting a role for growth factors in stimulating ER and fibrosis. IGF-1 (insulin-like growth factor 1) expression was increased and induced a fourfold increase of an ERE construct.Conclusions: Our data show 1) a critical role for ER and let-7 in lung fibrosis, and 2) that IGF may stimulate ER in an E2-independent manner. These results underscore the role of sex steroid hormones and their receptors in diseases that demonstrate a sex prevalence, such as IPF.

Connecting sex differences, estrogen signaling, and microRNAs in cardiac fibrosis

Sex differences are evident in the pathophysiology of heart failure (HF). Progression of HF is promoted by cardiac fibrosis and no fibrosis-specific therapies are currently available. The fibrotic response is mediated by cardiac fibroblasts (CFs), and a central event is their phenotypic transition to pro-fibrotic myofibroblasts. These myofibroblasts may arise from various cellular origins including resident CFs and epicardial and endothelial cells. Both female subjects in clinical studies and female animals in experimental studies generally present less cardiac fibrosis compared with males. This difference is at least partially considered attributable to the ovarian hormone 17β-estradiol (E2). E2 signals via estrogen receptors to regulate genes are involved in the fibrotic response and myofibroblast transition. Besides protein-coding genes, E2 also regulates transcription of microRNA that modulate cardiac fibrosis. Sex dimorphism, E2, and miRNAs form multi-level regulatory networks in the pathophysiology of cardiac fibrosis, and the mechanism of these networks is not yet fully deciphered. Therefore, this review is aimed at summarizing current knowledge on sex differences, E2, and estrogen receptors in cardiac fibrosis, emphasizing on microRNAs and myofibroblast origins. KEY MESSAGES: • E2 and ERs regulate cardiac fibroblast function. • E2 and ERs may distinctly affect male and female cardiac fibrosis pathophysiology. • Sex, E2, and miRNAs form multi-level regulatory networks in cardiac fibrosis. • Sex-dimorphic and E2-regulated miRNAs affect mesenchymal transition.

Tamoxifen affects chronic pancreatitis-related fibrogenesis in an experimental mouse model: an effect beyond Cre recombination

Tamoxifen is very successfully used for the induction of Cre^ERT‐mediated genomic recombination in conditional mouse models. Recent studies, however, indicated that tamoxifen might also affect the fibrotic response in several disease models following administration, both in vitro and in vivo. In order to investigate a possible effect of tamoxifen on pancreatic fibrogenesis and to evaluate an optimal treatment scheme in an experimental pancreatitis mouse model, we administered tamoxifen by oral gavage to both male and female C57BL/6J mice and then waited for different periods of time before inducing chronic pancreatitis by cerulein. We observed a sex‐specific and time‐dependent effect of tamoxifen on the fibrotic response as measured by collagen deposition and the number of myofibroblasts and macrophages. The findings of in vitro studies, in which cerulein was administrated with or without 4‐hydroxytamoxifen to stimulate primary murine female and male pancreatic stellate cells, supported our in vivo observations. Real‐time PCR also indicated that this effect may be related to differences in ERα expression between female and male stellate cells. Our data demonstrate that tamoxifen administration has unignorable side effects, which affect the experimental outcome in a cerulein‐based model of chronic pancreatitis in mice. We suggest a 2‐week waiting period before cerulein administration to reduce side effects to a minimum for the described fibrosis model in female mice.

Sex-specific influence on cardiac structural remodeling and therapy in cardiovascular disease

BACKGROUND

Cardiovascular diseases (CVDs) culminating into heart failure (HF) are major causes of death in men and women. Prevalence and manifestation, however, differ between sexes, since men mainly present with coronary artery disease (CAD) and myocardial infarction (MI), and post-menopausal women predominantly present with hypertension. These discrepancies are probably influenced by underlying genetic and molecular differences in structural remodeling pathways involved in hypertrophy, inflammation, fibrosis, and apoptosis. In general, men mainly develop eccentric forms, while women develop concentric forms of hypertrophy. Besides that, women show less inflammation, fibrosis, and apoptosis upon HF. This seems to emerge, at least partially, from the fact that the underlying pathways might be modulated by estrogen, which changes after menopause due to declining of the estrogen levels.

CONCLUSION

In this review, sex-dependent alterations in adverse cardiac remodeling are discussed for various CVDs. Moreover, potential therapeutic options, like estrogen treatment, are reviewed.

Non-genomic Effects of Estrogen on Cell Homeostasis and Remodeling With Special Focus on Cardiac Ischemia/Reperfusion Injury

This review takes into consideration the main mechanisms involved in cellular remodeling following an ischemic injury, with special focus on the possible role played by non-genomic estrogen effects. Sex differences have also been considered. In fact, cardiac ischemic events induce damage to different cellular components of the heart, such as cardiomyocytes, vascular cells, endothelial cells, and cardiac fibroblasts. The ability of the cardiovascular system to counteract an ischemic insult is orchestrated by these cell types and is carried out thanks to a number of complex molecular pathways, including genomic (slow) or non-genomic (fast) effects of estrogen. These pathways are probably responsible for differences observed between the two sexes. Literature suggests that male and female hearts, and, more in general, cardiovascular system cells, show significant differences in many parameters under both physiological and pathological conditions. In particular, many experimental studies dealing with sex differences in the cardiovascular system suggest a higher ability of females to respond to environmental insults in comparison with males. For instance, as cells from females are more effective in counteracting the ischemia/reperfusion injury if compared with males, a role for estrogen in this sex disparity has been hypothesized. However, the possible involvement of estrogen-dependent non-genomic effects on the cardiovascular system is still under debate. Further experimental studies, including sex-specific studies, are needed in order to shed further light on this matter.

Sex disparities in clinical characteristics and prognosis of immunoglobulin G4–related disease: a prospective study of 403 patients

Objectives

To study the impact of sex on the clinical presentation of IgG4-related disease (IgG4-RD).

Methods

We prospectively enrolled 403 newly diagnosed IgG4-RD patients. We compared the demographic features, clinical manifestations, organ involvement, laboratory tests and treatment outcomes between female and male patients. The organs involved were divided into superficial organs (salivary glands, lacrimal glands, orbit, sinus and skin) and internal organs (all the other organs). The patients treated with glucocorticoids with or without additional immunosuppressants were included in the assessment of treatment outcomes, and potential confounding factors were corrected by propensity score matching or multivariate Cox regression analysis.

Results

Female patients showed younger age at both symptom onset and diagnosis, and a longer interval between symptom onset and diagnosis. Allergy history, Mikulicz’s disease and thyroiditis were more common in female patients, while autoimmune pancreatitis, sclerosing cholangitis and retroperitoneal fibrosis were more common in male patients. In accordance, female patients more frequently presented with superficial organ involvement, while male patients more frequently had internal organ involvement, and the discrepancy was more prominent in the patients with older age. Male sex was associated with higher peripheral eosinophils, CRP and IgG4 levels at baseline. In response to glucocorticoid-based therapies, male sex was associated with a higher IgG4-RD responder index during follow-up as well as a greater risk of relapse (hazard ratio 3.14, P = 0.003).

Conclusion

Our study revealed the sex disparities in clinical characteristics of IgG4-RD, and indicated that male sex was independently associated with worse prognosis in response to glucocorticoid-based therapies.

Genistein inhibits Ang II-induced CRP and MMP-9 generations via the ER-p38/ERK1/2-PPARγ-NF-κB signaling pathway in rat vascular smooth muscle cells

AIMS

C-reactive protein (CRP) and matrix metalloproteinase (MMP)-9 are involved in the inflammation of atherosclerosis lesions. Genistein (Gen) has been demonstrated to exert beneficial effect on the cardiovascular system. However, it remains unclear whether Gen produces anti-inflammatory effect in vascular smooth muscle cells (VSMCs). Therefore, we investigated the effects of Gen on CRP and MMP-9 expressions induced by angiotensin (Ang) II in VSMCs and the related molecular mechanism.

MAIN METHODS

Rat VSMCs were cultured, and Ang II was used as a stimulant for CRP and MMP-9 expressions. CRP level was measured by ELISA. The mRNA and protein expressions of related indexes were identified by reverse transcription-polymerase chain reaction and western blot, respectively.

KEY FINDINGS

Gen inhibited Ang II-stimulated CRP and MMP-9 mRNA and protein expressions in concentration- and time-dependent manners. Additionally, Gen ameliorated Ang II-induced p-ERK1/2, p-p38 and NF-κB expressions, antagonized Ang II-downregulated peroxisome proliferation-activated receptor (PPAR) γ and estrogen receptor (ER) β expressions. After treating the VSMCs with GW9662 or ICI182780 in Gen treated groups, inhibitory effect of Gen on CRP and MMP-9 expressions were antagonized in Ang II-stimulated VSMCs. The treatment of VSMCs with ICI182780 abolished downregulations of p-p38/p-ERK1/2, and antagonized upregulation of PPARγ by Gen in Ang II-stimulated VSMCs. Moreover, the inhibitory effect of Gen on Ang II-stimulated NF-κB expression was abolished after preincubation of VSMCs with GW9662 in Gen treated groups.

SIGNIFICANCE

Gen exerts anti-inflammatory property via the ER-p38/ERK1/2-PPARγ-NF-κB-CRP/MMP-9 signal pathway in Ang II-stimulated VSMCs.

Estrogen receptor beta maintains expression of KLF15 to prevent cardiac myocyte hypertrophy in female rodents

Maintaining a healthy, anti-hypertrophic state in the heart prevents progression to cardiac failure. In humans, angiotensin II (AngII) indirectly and directly stimulates hypertrophy and progression, while estrogens acting through estrogen receptor beta (ERβ) inhibit these AngII actions. The KLF15 transcription factor has been purported to provide anti-hypertrophic action. In cultured neonatal rat cardiomyocytes, we found AngII inhibited KLF1 expression and nuclear localization, substantially prevented by estradiol (E2) or β-LGND2 (β-LGND2), an ERβ agonist. AngII stimulation of transforming growth factor beta expression in the myocytes activated p38α kinase via TAK1 kinase, inhibiting KLF15 expression. All was comparably reduced by E2 or β-LGND2. Knockdown of KLF15 in the myocytes induced myocyte hypertrophy and limited the anti-hypertrophic actions of E2 and β-LGND2. Key aspects were confirmed in an in-vivo model of cardiac hypertrophy. Our findings define additional anti-hypertrophic effects of ERβ supporting testing specific receptor agonists in humans to prevent progression of cardiac disease.

Membrane estrogen receptors signal to determine transcription factor function

Estrogen receptors (ER) alpha and beta as well as many other steroid receptors are found both within the nucleus and outside the nucleus. This includes extra-nuclear receptors in many organelles, including mitochondria, endoplasmic reticulum, cytosolic endosomes, and membrane lipid rafts, such as caveolae. The functions of these receptors in the various extra-nuclear cell organelles are not well described, but progress for understanding steroid receptor signaling from the membrane has advanced. In this Review I will discuss the enlarging role of membrane ER signaling to the expression, cell localization, and function of transcription factors that are essential to mediate cell physiology or pathophysiology in many organs.

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.

Hormone receptor expression in human fascial tissue

Many epidemiologic, clinical, and experimental findings point to sex differences in myofascial pain in view of the fact that adult women tend to have more myofascial problems with respect to men. It is possible that one of the stimuli to sensitization of fascial nociceptors could come from hormonal factors such as estrogen and relaxin, that are involved in extracellular matrix and collagen remodeling and thus contribute to functions of myofascial tissue. Immunohistochemical and molecular investigations (real-time PCR analysis) of relaxin receptor 1 (RXFP1) and estrogen receptor-alpha (ERα) localization were carried out on samples of human fascia collected from 8 volunteers patients during orthopedic surgery (all females, between 42 and 70 yrs, divided into pre- and post-menopausal groups), and in fibroblasts isolated from deep fascia, to examine both protein and RNA expression levels. We can assume that the two sex hormone receptors analyzed are expressed in all the human fascial districts examined and in fascial fibroblasts culture cells, to a lesser degree in the post-menopausal with respect to the pre-menopausal women. Hormone receptor expression was concentrated in the fibroblasts, and RXFP1 was also evident in blood vessels and nerves. Our results are the first demonstrating that the fibroblasts located within different districts of the muscular fasciae express sex hormone receptors and can help to explain the link between hormonal factors and myofascial pain. It is known, in fact, that estrogen and relaxin play a key role in extracellular matrix remodeling by inhibiting fibrosis and inflammatory activities, both important factors affecting fascial stiffness and sensitization of fascial nociceptors.