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

Erxian decoction ameliorates myocardial tissue damage through activating PI3K/AKT signaling pathway in ovariectomized rats

BACKGROUND

Erxian decoction (EXD) is an empirical formula for treating cardiovascular disease, our previous work has shown that EXD could improve the cardiovascular structure and function in ovariectomized (OVX) rats, but its pharmacological mechanism is still unclear.

MATERIALS AND METHODS

Network pharmacology was utilized to assess the key active components and central targets of EXD in treating postmenopausal cardiovascular disease. Then, an OVX rat model was established, HE staining and transmission electron microscope were utilized to observe myocardial tissue morphology, TUNEL staining was utilized to detect cardiomyocyte apoptosis, western blot, and ELISA were used to confirm efficacy and pathway of EXD.

RESULTS

The network pharmacology prediction results showed that 129 common targets were identified by intersecting EXD targets and postmenopausal cardiovascular disease targets, including AKT1, TNF, IL-6, IL-1β, PTGS2 and other core targets, apoptosis, PI3K/AKT, and other signaling pathways may be closely related to postmenopausal cardiovascular disease. After ovariectomy, the myocardial tissue of rats was damaged, the expression level of PI3K/AKT pathway-related molecules in the myocardial tissue were decreased, the apoptosis index of cardiomyocytes was increased, and the levels of inflammatory factors (TNF-α, IL-6, and IL-1β) were enhanced. EXD intervention could improve myocardial tissue injury, EXD could up-regulate the protein expression of PI3K and p-AKT in myocardial tissue, and thereby prevent myocardial cell apoptosis. At the same time, EXD downregulated the levels of inflammatory factors in serum of ovariectomized rats.

CONCLUSION

EXD may prevent myocardial tissue damage through induction of the PI3K/AKT signaling pathway, thereby reducing cardiomyocyte apoptosis and inflammation. EXD may be a potential drug for the treatment of postmenopausal cardiovascular disease.

Pembrolizumab-Associated Cardiotoxicity: A Retrospective Analysis of the FDA Adverse Events Reporting System

BACKGROUND

Immune checkpoint inhibitors (ICIs) have been successfully used in the previous decade for the treatment of a variety of malignancies. Adverse events (AEs) can cause many symptoms, most notably cardiac. We analyzed the frequency of these adverse events, comparing pembrolizumab and other ICIs.

METHODS

Using the Food and Drug Administration (FDA) adverse event reporting database (FAERS), we searched for all adverse events of interest reported for every ICI included in this study. After obtaining the data, we conducted a disproportionality analysis using the reporting odds ratio (ROR) and the information component (IC).

RESULTS

A total of 6719 ICI-related cardiac adverse events of interest were reported in the database. Serious outcomes were reported in 100% of the cases, with 34.3% of the cases ending fatally. Compared with all other medications in the database, pembrolizumab use was more frequently associated with myocarditis, pericardial disease, heart failure, and atrial fibrillation. No difference was found in cardiotoxicity between different ICIs.

CONCLUSIONS

Although infrequent, cardiac AEs in pembrolizumab use are associated with serious outcomes and high mortality. Prospective studies are needed to further research the connection between ICI use and cardiotoxicity.

Changes in cardiovascular arachidonic acid metabolism in experimental models of menopause and implications on postmenopausal cardiac hypertrophy

Menopause is a normal stage in the human female aging process characterized by the cessation of menstruation and the ovarian production of estrogen and progesterone hormones. Menopause is associated with an increased risk of several different diseases. Cardiovascular diseases are generally less common in females than in age-matched males. However, this female advantage is lost after menopause. Cardiac hypertrophy is a disease characterized by increased cardiac size that develops as a response to chronic overload or stress. Similar to other cardiovascular diseases, the risk of cardiac hypertrophy significantly increases after menopause. However, the exact underlying mechanisms are not yet fully elucidated. Several studies have shown that surgical or chemical induction of menopause in experimental animals is associated with cardiac hypertrophy, or aggravates cardiac hypertrophy induced by other stressors. Arachidonic acid (AA) released from the myocardial phospholipids is metabolized by cardiac cytochrome P450 (CYP), cyclooxygenase (COX), and lipoxygenase (LOX) enzymes to produce several eicosanoids. AA-metabolizing enzymes and their respective metabolites play an important role in the pathogenesis of cardiac hypertrophy. Menopause is associated with changes in the cardiovascular levels of CYP, COX, and LOX enzymes and the levels of their metabolites. It is possible that these changes might play a role in the increased risk of cardiac hypertrophy after menopause.

The Interaction of Vasopressin with Hormones of the Hypothalamo-Pituitary-Adrenal Axis: The Significance for Therapeutic Strategies in Cardiovascular and Metabolic Diseases

A large body of evidence indicates that vasopressin (AVP) and steroid hormones are frequently secreted together and closely cooperate in the regulation of blood pressure, metabolism, water-electrolyte balance, and behavior, thereby securing survival and the comfort of life. Vasopressin cooperates with hormones of the hypothalamo-pituitary-adrenal axis (HPA) at several levels through regulation of the release of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and multiple steroid hormones, as well as through interactions with steroids in the target organs. These interactions are facilitated by positive and negative feedback between specific components of the HPA. Altogether, AVP and the HPA cooperate closely as a coordinated functional AVP-HPA system. It has been shown that cooperation between AVP and steroid hormones may be affected by cellular stress combined with hypoxia, and by metabolic, cardiovascular, and respiratory disorders; neurogenic stress; and inflammation. Growing evidence indicates that central and peripheral interactions between AVP and steroid hormones are reprogrammed in cardiovascular and metabolic diseases and that these rearrangements exert either beneficial or harmful effects. The present review highlights specific mechanisms of the interactions between AVP and steroids at cellular and systemic levels and analyses the consequences of the inappropriate cooperation of various components of the AVP-HPA system for the pathogenesis of cardiovascular and metabolic diseases.

New insights into the pathogenesis of SARS-CoV-2 during and after the COVID-19 pandemic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the respiratory distress condition known as COVID-19. This disease broadly affects several physiological systems, including the gastrointestinal, renal, and central nervous (CNS) systems, significantly influencing the patient's overall quality of life. Additionally, numerous risk factors have been suggested, including gender, body weight, age, metabolic status, renal health, preexisting cardiomyopathies, and inflammatory conditions. Despite advances in understanding the genome and pathophysiological ramifications of COVID-19, its precise origins remain elusive. SARS-CoV-2 interacts with a receptor-binding domain within angiotensin-converting enzyme 2 (ACE2). This receptor is expressed in various organs of different species, including humans, with different abundance. Although COVID-19 has multiorgan manifestations, the main pathologies occur in the lung, including pulmonary fibrosis, respiratory failure, pulmonary embolism, and secondary bacterial pneumonia. In the post-COVID-19 period, different sequelae may occur, which may have various causes, including the direct action of the virus, alteration of the immune response, and metabolic alterations during infection, among others. Recognizing the serious adverse health effects associated with COVID-19, it becomes imperative to comprehensively elucidate and discuss the existing evidence surrounding this viral infection, including those related to the pathophysiological effects of the disease and the subsequent consequences. This review aims to contribute to a comprehensive understanding of the impact of COVID-19 and its long-term effects on human health.

Beyond hot flashes: Exploring the role of estrogen therapy in postmenopausal women for myocardial infarction prevention and recovery

Myocardial infarction (MI) commonly known as "heart attack" results from the blockage of blood flow to the heart. Postmenopausal women face an elevated risk of MI due to declining estrogen levels, a hormone pivotal in maintaining cardiovascular health. It promotes vasodilation, reduce inflammation, and improves lipid profiles. While estrogen therapy shows promise in mitigating MI risk for postmenopausal woman, its efficacy in prevention and recovery remains a subject of debate. This review provides a critical assessment of existing evidence on estrogen therapy's cardioprotective effects for postmenopausal women. It delves into estrogen's role in vascular function enhancement, inflammation reduction, and lipid metabolism modulation. Additionally, it addresses the various forms of estrogen therapy, administration methods, dosage considerations, safety implications, and associated risks. The review highlights the existing controversies and knowledge gaps related to estrogen therapy for MI prevention. It underscores the urgency for in-depth research to decipher the nexus between estrogen therapy and MI risk, especially concerning primary prevention and specific postmenopausal subgroups. Future studies should investigate optimal formulations, doses, and administration routes of estrogen therapy as well as assess treatment timing and duration. Comparative studies and long-term follow-up are necessary to inform clinical decision-making and improve patient care. Addressing these research gaps will empower clinicians to make more judicious choices about estrogen therapy for MI prevention and recovery in postmenopausal women, aiming for enhanced patient outcomes.

Targeting estrogen receptor signaling for treating heart failure

Heart failure (HF) is a significant public health problem worldwide. It has long been noted that premenopausal women, compared to postmenopausal women and men, have lower rates for developing this disease, as well as subsequent morbidity and mortality. This difference has been attributed to estrogen playing a cardioprotective role in these women, though exactly how it does so remains unclear. In this review, we examine the presence of estrogen receptors within the cardiovascular system, as well as the role they play behind the cardioprotective effect attributed to estrogen. Furthermore, we highlight the underlying mechanisms behind their alleviation of HF, as well as possible treatment approaches, such as hormone replacement therapy and exercise regimens, to manipulate these mechanisms in treating and preventing HF.

Cardioprotective O-GlcNAc signaling is elevated in murine female hearts via enhanced O-GlcNAc transferase activity

The post-translational modification of intracellular proteins by O-linked β-GlcNAc (O-GlcNAc) has emerged as a critical regulator of cardiac function. Enhanced O-GlcNAcylation activates cytoprotective pathways in cardiac models of ischemia-reperfusion (I/R) injury; however, the mechanisms underpinning O-GlcNAc cycling in response to I/R injury have not been comprehensively assessed. The cycling of O-GlcNAc is regulated by the collective efforts of two enzymes: O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), which catalyze the addition and hydrolysis of O-GlcNAc, respectively. It has previously been shown that baseline heart physiology and pathophysiology are impacted by sex. Here, we hypothesized that sex differences in molecular signaling may target protein O-GlcNAcylation both basally and in ischemic hearts. To address this question, we subjected male and female WT murine hearts to ex vivo ischemia or I/R injury. We assessed hearts for protein O-GlcNAcylation, abundance of OGT, OGA, and glutamine:fructose-6-phosphate aminotransferase (GFAT2), activity of OGT and OGA, and UDP-GlcNAc levels. Our data demonstrate elevated O-GlcNAcylation in female hearts both basally and during ischemia. We show that OGT activity was enhanced in female hearts in all treatments, suggesting a mechanism for these observations. Furthermore, we found that ischemia led to reduced O-GlcNAcylation and OGT-specific activity. Our findings provide a foundation for understanding molecular mechanisms that regulate O-GlcNAcylation in the heart and highlight the importance of sex as a significant factor when assessing key regulatory events that control O-GlcNAc cycling. These data suggest the intriguing possibility that elevated O-GlcNAcylation in females contributes to reduced ischemic susceptibility.

Astragalus (Astragalus mongholicus) Improves Ventricular Remodeling via ESR1 Downregulation RhoA/ROCK Pathway

Astragalus (Astragalus mongholicus) alleviates myocardial remodeling caused by hypertension. However, the detailed molecular mechanism is unclear. This study aims to investigate the effect of Astragalus on ventricular remodeling in ovariectomized spontaneous hypertensive rats (OVX-SHR).Female SHR/NCrl rats were subjected to bilateral ovariectomy to establish the OVX-SHR model and treated with Astragalus extract by gavage. The hemodynamics and cardiac function parameters were measured. HE and Masson staining were used to detect the pathological structure of myocardial remodeling and observe the hyperplasia of myocardial collagen fibers. The immunohistochemistry tested the level of α-SMA. The expression levels of inflammatory cytokines, IκB, p65, Cleaved-Caspase3, RhoA, and ROCK1/2 were detected using Western blot. The method of qRT-PCR measured the expression of matrix metalloproteinase (MMP-2 and MMP-9).Hemodynamic and cardiac function parameters were significantly improved after a high dose of Astragalus extract and Valsartan treatment. The myocardial integrity of the model group was significantly reduced, arranged loosely, and disordered, while the expression of α-SMA was increased. However, Astragalus extract and Valsartan treatments significantly reduced the pathological damage and α-SMA. The levels of TNF-α, IL-1β, IL-6, TGF-β, MMP-2, and MMP-9 in the model group were increased but decreased after Astragalus extract treatment. Adding an ESR1 inhibitor attenuated the improvement effect of Astragalus extract on myocardial remodeling and restored the expression of RhoA and ROCK1/2.Astragalus extract attenuates the cardiac damage in OVX-SHR by downregulating the RhoA/ROCK pathway through ESR1.

The Role of Estrogen Receptors in Health and Disease

Many biological and physiological events, including growth, development, and metabolism of reproductive and non-reproductive tissues in men and women, are regulated by estrogens and estrogen receptors (ERs) [...].

Comparative Studies on the Anti-Inflammatory and Apoptotic Activities of Four Greek Essential Oils: Involvement in the Regulation of NF-κΒ and Steroid Receptor Signaling

Essential oils (EOs) are well-known for their anti-fungal, anti-microbial, anti-inflammatory and relaxing activities. Steroid hormones, especially glucocorticoids, are also well-known for their anti-inflammatory activities and control of the hypothalamus-pituitary-adrenal (HPA) axis and glucose homeostasis. The biological activities of glucocorticoids render them the most widely prescribed anti-inflammatory drugs, despite their adverse side effects. In this study, comparative studies of the anti-inflammatory activities and interference with glucocorticoids receptor (GR) and estrogen receptor (ER) signaling of EOs from Greek Oregano, Melissa officinalis, Lavender and from the Chios Mastic, produced from the Greek endemic mastic tree, were performed in Human Embryonic Kidney 293 (HEK-293) cells. Chios Mastic (Mastiha) and oregano EOs exhibited the highest anti-inflammatory activities. The former showed a reduction in both NF-κB activity and protein levels. Mastic essential oil also caused a reduction in GR protein levels that may compensate for its boosting effect on dexamethasone (DEX)-induced GR transcriptional activation, ending up in no induction of the gluconeogenic phoshoenolpyruvate carboxykinase (PEPCK) protein levels that constitute the GR target. Oregano, Melissa officinalis and lavender EOs caused the suppression of the transcriptional activation of GR. Furthermore, the most active EO, that taken from Melissa officinalis, showed a reduction in both GR and PEPCK protein levels. Thus, the anti-inflammatory and anti-gluconeogenic activities of the EOs were uncovered, possibly via the regulation of GR signaling. Moreover, cytotoxic actions of Melissa officinalis and lavender EOs via the induction of mitochondrial-dependent apoptosis were revealed. Our results highlight these essentials oils' anti-inflammatory and apoptotic actions in relation to their implication on the regulation of steroid hormones' actions, uncovering their potential use in steroid therapy, with many applications in pharmaceutical and health industries as anti-cancer, anti-hyperglycemic and anti-inflammatory supplements.

Estrogen downregulates CD73/adenosine axis hyperactivity via adaptive modulation PI3K/Akt signaling to prevent myocarditis and arrhythmias during chronic catecholamines stress

BACKGROUND

During myocardial damage, the sex hormone estrogen and CD73, the main enzyme that converts AMP into adenosine, are cardioprotective molecules. However, it is unclear how these two molecules work together to provide cardioprotection. The current study aimed to elucidate the interaction between estrogen and CD73 under chronic stress.

METHODS

Ovariectomy and SHAM operations were done on FVB wild-type (WT) female mice. Two weeks after the operation, the mice were treated with daily isoproterenol (10 mg/kg/day) injections for 14 days. The effect of E2 on relevant cardiac injury biomarkers (BNP, ANP), myocardial morphology (cardiomyocyte surface area), electrocardiography, CD73 protein expression and activity, and macrophage (CD86 + and CD206 +) infiltrations were assessed. In vitro, H9C2 cells were treated with 1 nM of estrogen and 10 mM APCP (CD73 inhibitor α, β-methylene adenosine-5'-diphosphate), 10 µM isoproterenol and 20 µm LY294002 (PI3K inhibitor) for 24 h and western blot was done to elucidate the mechanism behind the effect of estrogen on the CD73/adenosine axis.

RESULTS

Estrogen deficiency during chronic catecholamine stress caused myocardial injury, thereby triggering the hyperactivity of the CD73/adenosine axis, which aggravated myocarditis, adverse remodeling, and arrhythmias. However, estrogen normalizes CD73/Adenosine axis via the upregulation of PI3K/Akt pathways to prevent adverse outcomes during stress. In vivo results showed that the inhibition of PI3K significantly decreased PI3K/Akt pathways while upregulating the CD73/adenosine axis and apoptosis.

CONCLUSION

Estrogen's pleiotropy cardioprotection mechanism during stress includes its normalization of the CD73/Adenosine axis via the PI3K/Akt pathway. Video Abstract.

Emerging Evidence on Membrane Estrogen Receptors as Novel Therapeutic Targets for Central Nervous System Pathologies

Nuclear- and membrane-initiated estrogen signaling cooperate to orchestrate the pleiotropic effects of estrogens. Classical estrogen receptors (ERs) act transcriptionally and govern the vast majority of hormonal effects, whereas membrane ERs (mERs) enable acute modulation of estrogenic signaling and have recently been shown to exert strong neuroprotective capacity without the negative side effects associated with nuclear ER activity. In recent years, GPER1 was the most extensively characterized mER. Despite triggering neuroprotective effects, cognitive improvements, and vascular protective effects and maintaining metabolic homeostasis, GPER1 has become the subject of controversy, particularly due to its participation in tumorigenesis. This is why interest has recently turned toward non-GPER-dependent mERs, namely, mERα and mERβ. According to available data, non-GPER-dependent mERs elicit protective effects against brain damage, synaptic plasticity impairment, memory and cognitive dysfunctions, metabolic imbalance, and vascular insufficiency. We postulate that these properties are emerging platforms for designing new therapeutics that may be used in the treatment of stroke and neurodegenerative diseases. Since mERs have the ability to interfere with noncoding RNAs and to regulate the translational status of brain tissue by affecting histones, non-GPER-dependent mERs appear to be attractive targets for modern pharmacotherapy for nervous system diseases.

Cardio-Metabolic Health and HRT in Menopause: Novel Insights in Mitochondrial Biogenesis and RAAS

Recent evidence shows the cardiometabolic effects of estrogen administration in postmenopausal women. Women have a cardiometabolic advantage during their reproductive years, which is lost at menopause due to declining estradiol (E2). E2, also known as 17-beta-estradiol, has diverse effects in its target tissues, including the cardiovascular (CV) system, through genomic and non-genomic signaling. Metabolic changes characteristic of menopause include a worsening lipid profile, changes in body fat distribution, epicardial and pericardial fat deposition, increased susceptibility to weight gain, and increased blood pressure, resulting in an increased risk of accelerated cardiovascular disease (CVD) development. E2 mediates its cardioprotective actions by increasing mitochondrial biogenesis, angiogenesis, and vasodilation, decreasing reactive oxygen species (ROS) and oxidative stress, and modulating the renin-angiotensin-aldosterone system (RAAS). In this review, we assess whether it is prudent to develop an approach to managing postmenopausal women based on modifying the patient's CV risk that includes human-identical hormone replacement therapy (HRT), modulation of RAAS, and stimulating mitochondrial biogenesis. Further research is needed to assess the safety and benefit of HRT to reduce cardiometabolic risk.

Er-xian ameliorates myocardial ischemia-reperfusion injury in rats through RISK pathway involving estrogen receptors

Curculigo orchioides (CUR) and Epimedium (EPI) are traditional Chinese medicines with estrogen-like biological activity, called Xianmao and Xianlingpi (Er-xian) in Chinese. However, whether Er-xian exerts protective effects on myocardial ischemia-reperfusion injury (MIRI) is unknown. This study aimed to investigate the cardioprotective effects of Er-xian preconditioning against MIRI and the underlying mechanisms. CUR or EPI was administered intragastrically to aged female rats as a monotherapy or combination therapy. 2 weeks later, a rat MIRI model was established. Myocardial infarction size, myocardial morphology, cTnT, cell apoptosis rate, intracellular calcium concentration, mitochondrial permeability transition pore (MPTP) opening and reperfusion injury salvage kinase (RISK) signaling pathway molecules were observed after the surgery. To evaluate the mechanisms of Er-xian, estrogen receptors antagonists ICI 182780 and G15 were used. In this study, Er-xian notably alleviated myocardial tissue damage, maintained mitochondrial morphology, reduced infarct size and cardiac markers, and increased sera levels of E2. Moreover, Er-xian inhibited calcium overload and mPTP opening, and decreased cardiomyocyte apoptosis. We found that the dual therapy of CUR and EPI elicited more noticeable results than CUR or EPI monotherapy. The significant protective effects of Er-xian on ischemia-reperfusion myocardium were attributed to the up-regulation of AKT, ERK1/2 and GSK-3β phosphorylation levels. The cardioprotective effects of Er-xian were significantly reduced after estrogen receptor blockade, especially GPER30. These results indicate that Er-xian attenuates MIRI through RISK signaling pathway and estrogen receptors are the critical mediators.

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.

Estrogen signaling as a bridge between the nucleus and mitochondria in cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality worldwide. Epidemiological studies indicate that pre-menopausal women are more protected against the development of CVDs compared to men of the same age. This effect is attributed to the action/effects of sex steroid hormones on the cardiovascular system. In this context, estrogen modulates cardiovascular function in physiological and pathological conditions, being one of the main physiological cardioprotective agents. Here we describe the common pathways and mechanisms by which estrogens modulate the retrograde and anterograde communication between the nucleus and mitochondria, highlighting the role of genomic and non-genomic pathways mediated by estrogen receptors. Additionally, we discuss the presumable role of bromodomain-containing protein 4 (BRD4) in enhancing mitochondrial biogenesis and function in different CVD models and how this protein could act as a master regulator of estrogen protective activity. Altogether, this review focuses on estrogenic control in gene expression and molecular pathways, how this activity governs nucleus-mitochondria communication, and its projection for a future generation of strategies in CVDs treatment.

Ischemic preconditioning/ischemic postconditioning alleviates anoxia/reoxygenation injury via the Notch1/Hes1/VDAC1 axis

Ischemic preconditioning (IPC), and ischemic postconditioning (IPost) have a significant protective effect on myocardial ischemia/reperfusion (MI/R) injury by alleviating oxidative stress and mitochondrial disturbances, although the underlying molecular mechanisms are unclear. The study was to demonstrate that cardioprotection against anoxia/reoxygenation (A/R) injury is transduced via the Notch1/Hes1/VDAC1 signaling pathway. Using mass spectrometry and tandem affinity purification (TAP), to screen for differentially expressed proteins associated with Hes1, followed by standard bioinformatics analysis. The co-immunoprecipitation (Co-IP) assay confirmed an interaction between Hes1 and VDAC1 proteins. H9c2 cells were transfected with Hes1 adenoviral N-terminal TAP vector (AD-NTAP/Hes1) and Hes1-short hairpin RNA adenoviral vector (AD-Hes1-shRNA) to establish A/R injury, IPC, and IPost models, respectively. The expression of Hes1 and VDAC1 proteins were measured by western blot analysis, while the levels of reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), and apoptosis were evaluated by flow cytometry. AD-NTAP/Hes1 can activate the exogenous protein expression of Hes1, thus decreasing creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) activity and promoting cell viability. The study found that VDAC1 was a potential target protein for Hes1 and the overexpression of Hes1 protein expression downregulated protein expression levels of VDAC1, reduced ROS production, stabilized ΔΨm, and inhibited apoptosis in H9c2 cells. Additionally, downregulation of Hes1 protein expression also upregulated VDAC1 protein expression, increased ROS production, imbalanced ΔΨm, promoted cell apoptosis, and attenuated the cardioprotection afforded by IPC and IPost. The Notch1/Hes1 signaling pathway activated by IPC/IPost can directly downregulate the protein expression of VDAC1 and consequently relieve A/R injury.

Estradiol Ameliorates Acute Kidney Ischemia-Reperfusion Injury by Inhibiting the TGF-βRI-SMAD Pathway

Renal ischemia–reperfusion injury (IRI) is less extensive in females than males in both animals and humans; however, this protection diminishes after menopause, suggesting that estrogen plays a pivotal role in IRI, but the underlying mechanism remains largely unknown. Our study found that 45 min of warm ischemia was sufficient to induce significant pathological changes without causing death in model animals. Compared with male rats, female rats exhibited less extensive apoptosis, kidney injury, and fibrosis; these effects were worsened in ovariectomized (OVX) rats and ameliorated upon estradiol (E₂) supplementation. Furthermore, the levels of TGF-βRI, but not TGF-βRII or TGF-β1, were significantly increased in OVX rats, accompanied by phosphorylated SMAD2/3 activation. Interestingly, the alteration trend of the nuclear ERα level was opposite that of TGF-βRI. Furthermore, dual luciferase reporter and chromatin immunoprecipitation assays showed that ERα could bind to the promoter region of TGF-βRI and negatively regulate its mRNA expression. Moreover, an in vitro study using NRK-52E cells showed that ERα knockdown blocked E₂-mediated protection, while TGF-βRI knockdown protected cells against hypoxic insult. The findings of this study suggest that renal IRI is closely related to the TGF-βRI-SMAD pathway in females and that E₂ exert its protective effect via the ERα-mediated transcriptional inhibition of TGF-βRI expression.

Sex Differences in Cardiovascular Diseases: A Matter of Estrogens, Ceramides, and Sphingosine 1-Phosphate

The medical community recognizes sex-related differences in pathophysiology and cardiovascular disease outcomes (CVD), culminating with heart failure. In general, pre-menopausal women tend to have a better prognosis than men. Explaining why this occurs is not a simple matter. For decades, sex hormones like estrogens (Es) have been identified as one of the leading factors driving these sex differences. Indeed, Es seem protective in women as their decline, during and after menopause, coincides with an increased CV risk and HF development. However, clinical trials demonstrated that E replacement in post-menopause women results in adverse cardiac events and increased risk of breast cancer. Thus, a deeper understanding of E-related mechanisms is needed to provide a vital gateway toward better CVD prevention and treatment in women. Of note, sphingolipids (SLs) and their metabolism are strictly related to E activities. Among the SLs, ceramide and sphingosine 1-phosphate play essential roles in mammalian physiology, particularly in the CV system, and appear differently modulated in males and females. In keeping with this view, here we explore the most recent experimental and clinical observations about the role of E and SL metabolism, emphasizing how these factors impact the CV system.

Sex-Related Effects on Cardiac Development and Disease

Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality. Interestingly, male and female patients with CVD exhibit distinct epidemiological and pathophysiological characteristics, implying a potentially important role for primary and secondary sex determination factors in heart development, aging, disease and therapeutic responses. Here, we provide a concise review of the field and discuss current gaps in knowledge as a step towards elucidating the “sex determination–heart axis”. We specifically focus on cardiovascular manifestations of abnormal sex determination in humans, such as in Turner and Klinefelter syndromes, as well as on the differences in cardiac regenerative potential between species with plastic and non-plastic sexual phenotypes. Sex-biased cardiac repair mechanisms are also discussed with a focus on the role of the steroid hormone 17β-estradiol. Understanding the “sex determination–heart axis” may offer new therapeutic possibilities for enhanced cardiac regeneration and/or repair post-injury.

Trpc6 Promotes Doxorubicin-Induced Cardiomyopathy in Male Mice With Pleiotropic Differences Between Males and Females

Background: Doxorubicin is a widely used and effective chemotherapy, but the major limiting side effect is cardiomyopathy which in some patients leads to congestive heart failure. Genetic variants in TRPC6 have been associated with the development of doxorubicin-induced cardiotoxicity, suggesting that TRPC6 may be a therapeutic target for cardioprotection in cancer patients. Methods: Assessment of Trpc6 deficiency to prevent doxorubicin-induced cardiac damage and function was conducted in male and female B6.129 and Trpc6 knock-out mice. Mice were treated with doxorubicin intraperitoneally every other day for a total of 6 injections (4 mg/kg/dose, cumulative dose 24 mg/kg). Cardiac damage was measured in heart sections by quantification of vacuolation and fibrosis, and in heart tissue by gene expression of Tnni3 and Myh7. Cardiac function was determined by echocardiography. Results: When treated with doxorubicin, male Trpc6-deficient mice showed improvement in markers of cardiac damage with significantly reduced vacuolation, fibrosis and Myh7 expression and increased Tnni3 expression in the heart compared to wild-type controls. Similarly, male Trpc6-deficient mice treated with doxorubicin had improved LVEF, fractional shortening, cardiac output and stroke volume. Female mice were less susceptible to doxorubicin-induced cardiac damage and functional changes than males, but Trpc6-deficient females had improved vacuolation with doxorubicin treatment. Sex differences were observed in wild-type and Trpc6-deficient mice in body-weight and expression of Trpc1, Trpc3 and Rcan1 in response to doxorubicin. Conclusions: Trpc6 promotes cardiac damage following treatment with doxorubicin resulting in cardiomyopathy in male mice. Female mice are less susceptible to cardiotoxicity with more robust ability to modulate other Trpc channels and Rcan1 expression.

G Protein-Coupled Estrogen Receptor Agonist G-1 Inhibits Mantle Cell Lymphoma Growth in Preclinical Models

Mantle cell lymphoma (MCL) is an aggressive form of non-Hodgkin’s B-cell lymphoma with poor prognosis. Despite recent advances, resistance to therapy and relapse remain significant clinical problems. G-protein-coupled estrogen receptor (GPER)-mediated estrogenic rapid signaling is implicated in the development of many cancers. However, its role in MCL is unknown. Here we report that GPER activation with selective agonist G-1 induced cell cycle arrest, DNA damage, mitochondria membrane potential abnormality, and eventually apoptosis of MCL cell lines. We found that G-1 induced DNA damage and apoptosis of MCL cells by promoting the expression of nicotinamide adenine dinucleotide phosphate oxidase and the generation of reactive oxygen species. In addition, G-1 inhibited MCL cell proliferation by inactivation of NF-κB signaling and exhibited anti-tumor functions in MCL xenografted mice. Most significantly, G-1 showed synergistic effect with ibrutinib making it a potential candidate for chemotherapy-free therapies against MCL.

The "Hitchhiker's Guide to the Galaxy" of Endothelial Dysfunction Markers in Human Fertility

Endothelial dysfunction is an early event in the pathogenesis of atherosclerosis and represents the first step in the pathogenesis of cardiovascular diseases. The evaluation of endothelial health is fundamental in clinical practice and several direct and indirect markers have been suggested so far to identify any alterations in endothelial homeostasis. Alongside the known endothelial role on vascular health, several pieces of evidence have demonstrated that proper endothelial functioning plays a key role in human fertility and reproduction. Therefore, this state-of-the-art review updates the endothelial health markers discriminating between those available for clinical practice or for research purposes and their application in human fertility. Moreover, new molecules potentially helpful to clarify the link between endothelial and reproductive health are evaluated herein.

Immuno-Endocrinology of COVID-19: The Key Role of Sex Hormones

Epidemiological evidence shows clear gender disparities in the Coronavirus 2019 Disease (COVID-19) severity and fatality. This may reflect the contribution of gender-related factors, such as sex hormones, to COVID-19 pathogenesis. However, the mechanism linking gender disparities to COVID-19 severity is still poorly understood. In this review, we will pinpoint several elements involved in COVID-19 pathogenesis that are regulated by the two main sex hormones, estrogen and androgen. These include tissue specific gene regulation of SARS-CoV2 entry factors, innate and adaptive immune responses to infection, immunometabolism, and susceptibility to tissue injury by cytopathic effect or hyper-inflammatory response. We will discuss the mechanistic link between sex hormone regulation of COVID-19 pathogenetic factors and disease severity. Finally, we will summarize current evidence from clinical studies and trials targeting sex hormones and their signalling in COVID-19. A better understanding of the role of sex hormones in COVID-19 may identify targets for therapeutic intervention and allow optimization of treatment outcomes towards gender-based personalised medicine.