The hypertensive potential of estrogen: An untold story

Acacetin as a natural cardiovascular therapeutic: mechanisms and preclinical evidence

Globally, cardiovascular disease (CVD) has emerged as a leading cause of mortality and morbidity. As the world's population ages, CVD incidence is on the rise, and extensive attention has been drawn to optimizing the therapeutic regimens. Acacetin, a natural flavonoid derived from various plants, has been demonstrated to have a wide spectrum of pharmacological properties, such as antioxidant, anti-inflammatory, anti-bacterial, and anti-tumor activities, as well as protective effects on diverse tissues and organs. Recently, increasing numbers of studies (mostly preclinical) have indicated that acacetin has potential cardiovascular protective effects and might become a novel therapeutic strategy for CVDs. The importance of acacetin in CVD treatment necessitates a systematic and comprehensive review of its protective effects on the cardiovascular system and the underlying mechanisms involved. Here, we first provide an overview of some basic properties of acacetin. Subsequently, the protective effects of acacetin on multiple CVDs, like arrhythmias, cardiac ischemia/reperfusion injury, atherosclerosis, myocardial hypertrophy and fibrosis, drug-induced cardiotoxicity, diabetic cardiomyopathy, hypertension, and cardiac senescence, are discussed in detail. The underlying mechanisms by which acacetin exhibits cardiovascular protection appear to involve suppressing oxidative stress, reducing inflammation, preventing cardiomyocyte apoptosis and endothelial cell injury, as well as regulating mitochondrial autophagy and lipid metabolism. Meanwhile, several critical signaling pathways have also been found to mediate the protection of acacetin against CVDs, including phosphoinositide 3-kinase/protein kinase B/mechanistic target of rapamycin (PI3K/Akt/mTOR), sirtuin 1/AMP-activated protein kinase/peroxisome proliferator-activated receptor-γ coactivator-1α (Sirt1/AMPK/PGC-1α), transforming growth factor-β1/small mothers against decapentaplegic 3 (TGF-β1/Smad3), protein kinase B/endothelial nitric oxide synthase (Akt/eNOS), and others. Finally, we highlight the existing problems associated with acacetin that need to be addressed, such as the requirement for clinical evidence and enhanced bioavailability, as well as its potential as a promising cardiovascular drug candidate.

The pharmaco-epigenetics of hypertension: a focus on microRNA

Hypertension is a major harbinger of cardiovascular morbidity and mortality. It predisposes to higher rates of myocardial infarction, chronic kidney failure, stroke, and heart failure than most other risk factors. By 2025, the prevalence of hypertension is projected to reach 1.5 billion people. The pathophysiology of this disease is multifaceted, as it involves nitric oxide and endothelin dysregulation, reactive oxygen species, vascular smooth muscle proliferation, and vessel wall calcification, among others. With the advent of new biomolecular techniques, various studies have elucidated a gaping hole in the etiology and mechanisms of hypertension. Indeed, epigenetics, DNA methylation, histone modification, and microRNA-mediated translational silencing appear to play crucial roles in altering the molecular phenotype into a hypertensive profile. Here, we critically review the experimentally determined associations between microRNA (miRNA) molecules and hypertension pharmacotherapy. Particular attention is given to the epigenetic mechanisms underlying the physiological responses to antihypertensive drugs like candesartan, and other relevant drugs like clopidogrel, aspirin, and statins among others. Furthermore, how miRNA affects the pharmaco-epigenetics of hypertension is especially highlighted.

Overlapping action of melatonin and female reproductive hormones-Understand the impact in pregnancy and menopause

Melatonin is an indolamine secreted to circulation by the pineal gland according to a circadian rhythm. Melatonin levels are higher during nighttime, and the principal function of this hormone is to organize the temporal night and day distribution of physiological adaptive processes. Besides hormonal pineal production, melatonin is synthesized in various organs and tissues like the ovaries or the placenta for local utilization. In addition to its function as a circadian messenger, melatonin is also associated with many physiological functions. For example, melatonin has antioxidant properties and is involved in the regulation of energy and bone metabolism, and reproduction. Melatonin impacts several stages of reproduction and the action across the hypothalamus-pituitary-gonadal axis is well described. However, it is not well understood how those actions impact the female reproductive hormones secretion nor the consequent physiological outcomes. Thus, the first part of this chapter describes the regulation of female reproductive hormone synthesis by melatonin. Moreover, melatonin and female reproductive hormones have coincident physiological functions. Life stages like pregnancy or menopause are characterized by alterations in the reproductive hormones secretion that may be associated with certain physiological stages. Therefore, the second part discusses whether melatonin fluctuations could have an overlapping role with reproductive hormones in contributing to clinical outcomes associated with pregnancy and menopause.

Selective Activation of G Protein-coupled Estrogen Receptor 1 Attenuates Atherosclerosis

Atherosclerosis remains a leading contributor to cardiovascular disease-associated morbidity and mortality. Interestingly, atherosclerosis-associated mortality rate is higher in men than women. This suggested a protective role for estrogen in the cardiovasculature. These effects of estrogen were initially thought to be mediated by the classic estrogen receptors, ER alpha, and beta. However, genetic knockdown of these receptors did not abolish estrogen's vasculoprotective effects suggesting that the other membranous Gprotein coupled estrogen receptor, GPER1, maybe the actual mediator. Indeed, in addition to its role in vasotone regulation, this GPER1 appears to play important roles in regulating vascular smooth cell phenotype, a critical player in the onset of atherosclerosis. Moreover, GPER1-selective agonists appear to reduce LDL levels by promoting the expression of LDL receptors as well as potentiating LDL re-uptake in liver cells. Further evidence also show that GPER1 can downregulate Proprotein Convertase Subtilisin/ Kexin type 9, leading to suppression of LDL receptor breakdown. Here, we review how selective activation of GPER1 might prevent or suppress atherosclerosis, with less side effects than those of the non-selective estrogen.

Gender-Related Differences in the Levels of Ambulatory BP and Intensity of Antihypertensive Treatment in Patients Undergoing Peritoneal Dialysis

Prior studies have shown that among patients with chronic kidney disease not yet on dialysis, the faster progression of kidney injury in men than in women is, at least partly, explained by sex differences in ambulatory blood pressure (BP) control. The present study aimed to investigate potential differences in the levels of ambulatory BP and intensity of antihypertensive treatment between men and women with end-stage kidney disease undergoing long-term peritoneal dialysis (PD). In a case-control design, 48 male PD patients were matched for age and heart failure status with 48 female patients in a 1:1 ratio. Ambulatory BP monitoring was performed with an oscillometric device, the Mobil-O-Graph (IEM, Stolberg, Germany). The BP-lowering medications actually taken by the patients were prospectively recorded. No gender-related differences were observed in 24 h systolic BP (129.0 ± 17.9 vs. 128.5 ± 17.6 mmHg, p = 0.890). In contrast, 24 h diastolic BP was higher in men than in women (81.5 ± 12.1 vs. 76.8 ± 10.3 mmHg, p = 0.042). As compared with women, men were being treated with a higher average number of antihypertensive medications daily (2.4 ± 1.1 vs. 1.9 ± 1.1, p = 0.019) and were more commonly receiving calcium-channel-blockers (70.8% vs. 43.8%, p = 0.007) and β-blockers (85.4% vs. 66.7%, p = 0.031). In conclusion, the present study shows that among PD patients, the levels of ambulatory BP and intensity of antihypertensive treatment are higher in men than in women. Longitudinal studies are needed to explore whether these gender-related differences in the severity of hypertension are associated with worse cardiovascular outcomes for male patients undergoing PD.

Sex differences in cardiovascular response to sepsis

Recently, there has been increased recognition of the importance of sex as a biological factor affecting disease and health. Many preclinical studies have suggested that males may experience a less favorable outcome in response to sepsis than females. The underlying mechanisms for these differences are still largely unknown but are thought to be related to the beneficial effects of estrogen. Furthermore, the immunosuppressive role of testosterone is also thought to contribute to the sex-dependent differences that are present in clinical sepsis. There are still significant knowledge gaps in this field. This mini-review will provide a brief overview of sex-dependent variables in relation to sepsis and the cardiovascular system. Preclinical animal models for sepsis research will also be discussed. The intent of this mini-review is to inspire interest for future considerations of sex-related variables in sepsis that should be addressed to increase our understanding of the underlying mechanisms in sepsis-induced cardiovascular dysfunction for the identification of therapeutic targets and improved sepsis management and treatment.

The association of hormone therapy with blood pressure control in postmenopausal women with hypertension: a secondary analysis of the Women's Health Initiative clinical trials

OBJECTIVE

The objective of this study was to assess the effect of menopausal hormone therapy (HT) on blood pressure control in postmenopausal women with hypertension.

METHODS

The Women's Health Initiative HT clinical trials were double-blinded, randomized, placebo-controlled studies of women aged 50 to 79 years testing the effects of HT (conjugated equine estrogens [CEE, 0.625 mg/d] or CEE + medroxyprogesterone acetate [MPA; 2.5 mg/d]) on risks for coronary heart disease and invasive breast cancer, the primary outcomes for efficacy and safety, respectively. This secondary analysis of the Women's Health Initiative HT trials examined a subsample of 9,332 women with hypertension (reported ever taking pills to treat hypertension or were taking antihypertensive medication) at baseline. Blood pressure was measured at baseline and up to 10 annual follow-up visits during the planned study phase. Antihypertensive medications were inventoried at baseline and years 1, 3, 6, and 9 during the study, and self-reported during extended follow-up: 2009-2010 and 2012-2013, which occurred median of 13 and 16 years after randomization, respectively. The intervention effect was estimated through year 6. Cumulative follow-up included all visits.

RESULTS

Compared with placebo, CEE-alone had significantly ( P = 0.02) higher systolic blood pressure (SBP) by mean (95% confidene interval [CI]) = 0.9 (0.2-1.5) mm Hg during the intervention phase. For cumulative follow-up, the CEE arm was associated with increased SBP by mean (95% CI) = 0.8 (0.1-1.4) mm Hg ( P = 0.02). Furthermore, CEE + MPA relative to placebo was associated with increased SBP by mean (95% CI) = 1.8 (1.2-2.5) mm Hg during the intervention phase ( P < 0.001). For cumulative follow-up, the CEE + MPA arm was associated with increased SBP by mean (95% CI) = 1.6 (1.0-2.3) mm Hg ( P < 0.001). The mean number of antihypertensive medications taken at each follow-up visit did not differ between randomization groups during the intervention or long-term extended follow-up of 16 years.

CONCLUSION

There was a small but statistically significant increase in SBP in both CEE-alone and CEE + MPA arms compared with placebo during both the intervention and cumulative follow-up phases among postmenopausal women with hypertension at baseline. However, this increase in SBP was not associated with an increased antihypertensive medication use over time among women randomized to HT compared with placebo.

Clinical characteristics and outcomes of ischemic stroke patients during Ramadan vs. non-Ramadan months: Is there a difference?

Objectives

To study the clinical characteristics and outcomes of patients experiencing an ischemic stroke during Ramadan vs. non-Ramadan months in a tertiary academic center in an Islamic country.

Methods

We retrospectively reviewed all patients with ischemic stroke (IS) in Ramadan and non-Ramadan months for four consecutive years (February 2016–June 2019). All demographics, vascular risk factors, laboratory results, modified Rankin Scale (mRS) at admission and discharge, National Institute Stroke Scale (NIHSS), and in-hospital complication data were collected for all patients.

Results

One thousand and 58 patients were included (non-Ramadan, n = 960; during Ramadan, n = 98). The mean age during Ramadan was 59 ± 13 years. Most non-Ramadan IS patients during Ramadan were male (68.5%; 57.1%, respectively). There was no statistical difference in vascular risk factors and medical history between the two groups. However, Ramadan patients had higher median NIHSS scores at discharge (p = 0.0045). In addition, more ICU admissions were noted among Ramadan patients (p = 0.009). In the gender-specific analysis for Ramadan patients, we found a statistically significant difference in smoking and urinary tract infection (p = 0.006, p = 0.005, respectively).

Conclusion

Based on our results, there was no difference, in general, between patients with IS during Ramadan and non-Ramadan months. However, IS patients had higher NIHSS scores at discharge and more ICU admissions during Ramadan. Last, we suggest future studies with larger sample sizes, longer duration, and including all types of strokes.

History of infertility and pregnancy outcomes in Project Viva: a prospective study

Background

Infertility has been associated with the risk of adverse pregnancy outcomes. It is not clear whether infertility and underlying causes of infertility or the use of medically assisted reproduction (MAR) therapies are responsible for the observed associations. In this study, we aimed to evaluate the association of history of infertility with pregnancy outcomes and identify whether the associations, if present, differed by subgroups defined by the use of MAR.

Methods

Prospective study of 2201 pregnant women from the Boston-area Project Viva cohort. The exposure was history of infertility based on self-reported time to pregnancy ≥12 mo (or ≥ 6 mo if ≥35 y) or use of MAR; a diagnosis of infertility or claims for infertility treatments from medical records. The outcomes included: gestational glucose tolerance (gestational diabetes, impaired glucose tolerance, isolated hyperglycemia vs. normoglycemia), hypertensive disorders (gestational hypertension/preeclampsia vs. normotension), gestational weight gain (inadequate/excessive vs. adequate), systolic (SBP) and diastolic blood pressure, birthweight-for-gestational age z-score (tertile 2 and 3 vs. 1), preterm birth (<37 vs. ≥37 weeks at delivery), and birth outcome (pregnancy loss vs. live birth). We performed linear and logistic/multinomial regression analyses adjusted for age, race/ethnicity, age at menarche, pre-pregnancy BMI, and prenatal smoking.

Results

Mean (SD) age was 32.0 (5.0) years, and 18.8% of women had history of infertility, 32.6% of whom used MAR. SBP across pregnancy was 0.72 mmHg higher in women with vs. without infertility (95% CI 0.02, 1.42). The associations were stronger among women who used MAR (β 1.32 mmHg, 95% CI 0.21, 2.44), especially among those who used gonadotropins or gonadotropin-releasing hormone [GnRH] agonists (β 1.91 mmHg, 95% CI 0.48, 3.35). Other outcomes were not associated with history of infertility.

Conclusions

A history of infertility was associated with higher SBP during pregnancy, with stronger associations among those who used gonadotropins or GnRH agonists. Future studies are needed to confirm these findings and determine their clinical implications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04885-8.

Estradiol Supplement or Induced Hypertension May Attenuate the Angiotensin II Type 1 Receptor Antagonist-Promoted Renal Blood Flow Response to Graded Angiotensin II Administration in Ovariectomized Rats

Backgrounds. Estrogen replacement therapy (ERT) and hypertension may influence females’ renin-angiotensin system (RAS) and its components. The angiotensin II (Ang II) type 1 receptor (AT1R) antagonist (losartan) may promote renal blood flow (RBF), and it is widely used in the clinic to control hypertension. The main objective of this study was the effects of estradiol or induced hypertension on RBF response to Ang II in losartan-treated ovariectomized (OVX) rats. Methods. Two groups of OVX rats were treated with placebo (group 1) and estradiol (group 2) for period of four weeks, and another group of OVX rats was subjected to induce hypertension by two-kidney one clip (2K1C) model (group 3). All the groups were subjected to the surgical procedure under anesthesia, and AT1R was blocked by losartan. RBF and renal vascular resistance (RVR) responses to Ang II administration were determined and compared. Results. Mean arterial (MAP) and renal perfusion (RPP) pressures in group 3 and uterus weight (UT) in group 2 were significantly more than other groups ( $P<0.05$ ). Ang II infusion resulted in dose-related percentage change increase in RBF and decrease in RVR. However, these responses in the OVX-estradiol and OVX-hypertensive rats were significantly lower than in the OVX-control group ( $P<0.05$ ). For instance, at the dose of 1000 ng/kg/min of Ang II administration, the percentage change of RBF was $45.1\pm 10.4\%$ , $17.9\pm 2.3\%$ , and $16.7\pm 4.7\%$ in the groups of 1 to 3, respectively. Conclusion. Losartan prescription in some conditions such as hypertension or ERT could worsen RBF and RVR responses to Ang II.

Impacts of Environmental Insults on Cardiovascular Aging

PURPOSE OF REVIEW

With cardiovascular disease (CVD) being the top cause of deaths worldwide, it is important to ensure healthy cardiovascular aging through enhanced understanding and prevention of adverse health effects exerted by external factors. This review aims to provide an updated understanding of environmental influences on cardiovascular aging, by summarizing epidemiological and mechanistic evidence for the cardiovascular health impact of major environmental stressors, including air pollution, endocrine-disrupting chemicals (EDCs), metals, and climate change.

RECENT FINDINGS

Recent studies generally support positive associations of exposure to multiple chemical environmental stressors (air pollution, EDCs, toxic metals) and extreme temperatures with increased risks of cardiovascular mortality and morbidity in the population. Environmental stressors have also been associated with a number of cardiovascular aging-related subclinical changes including biomarkers in the population, which are supported by evidence from relevant experimental studies. The elderly and patients are the most vulnerable demographic groups to majority environmental stressors. Future studies should account for the totality of individuals' exposome in addition to single chemical pollutants or environmental factors. Specific factors most responsible for the observed health effects related to cardiovascular aging remain to be elucidated.

Nitric Oxide and Immune Responses in Cancer: Searching for New Therapeutic Strategies

In recent years, there has been an increasing interest in understanding the mysterious functions of nitric oxide (NO) and how this pleiotropic signaling molecule contributes to tumorigenesis. This review attempts to expose and discuss the information available on the immunomodulatory role of NO in cancer and recent approaches to the role of NO donors in the area of immunotherapy. To address the goal, the following databases were searched to identify relevant literature concerning empirical evidence: The Cochrane Library, Pubmed, Medline, and EMBASE from 1980 through March 2020. Valuable attempts have been made to develop distinctive NO-based cancer therapy. Although the data do not allow generalization, the evidence seems to indicate that low/moderate levels may favor tumorigenesis, while higher levels would exert antitumor effects. In this sense, the use of NO donors could have an important therapeutic potential within immunotherapy, although there are still no clinical trials. The emerging understanding of NO-regulated immune responses in cancer may help unravel the recent features of this "doubleedged sword" in cancer physiological and pathologic processes and its potential use as a therapeutic agent for cancer treatment. In short, in this review, we discuss the complex cellular mechanism in which NO, as a pleiotropic signaling molecule, participates in cancer pathophysiology. We also debate the dual role of NO in cancer and tumor progression and clinical approaches for inducible nitric oxide synthase (iNOS) based therapy against cancer.

The Yin-Yang Dynamics in Cardiovascular Pharmacogenomics and Personalized Medicine

Studies of genetic variants and systems biology have indicated that Yin-Yang dynamics are especially meaningful for cardiovascular pharmacogenomics and personalized therapeutic strategies. The comprehensive concepts of Yin-Yang can be used to characterize the dynamical factors in the adaptive microenvironments of the complex cardiovascular systems. The Yin-Yang imbalances in the complex adaptive systems (CAS) at different levels and stages are essential for cardiovascular diseases (CVDs), including atherosclerosis, hypertension, and heart failure (HF). At the molecular and cellular levels, Yin-Yang interconnections have been considered critical for genetic variants and various pathways, mitophagy, cell death, and cholesterol homeostasis. The significance of the adaptive and spatiotemporal factors in the nonlinear Yin-Yang interactions has been identified in different pathophysiological processes such as fibrosis. The Yin-Yang dynamical balances between proinflammatory and anti-inflammatory cytokines have vital roles in the complex reactions to stress and impairments to the heart. Procoagulant and anticoagulant lipids and lipoproteins in plasma have the Yin-Yang roles that increase or decrease thrombin productions and thrombosis. At the systems level, the Yin-Yang type of relationships has been suggested between atrial fibrillation (AF), diastolic dysfunction (DD), and HF. Based on such perceptions, systemic and personalized cardiovascular profiles can be constructed by embracing the features of CAS, especially the microenvironments and the adaptative pathophysiological stages. These features can be integrated into the comprehensive Yin-Yang dynamics framework to identify more accurate biomarkers for better prevention and treatments. The goal of reestablishing ubiquitous Yin-Yang dynamical balances may become the central theme for personalized and systems medicine for cardiovascular diseases.

The Etiology and Pathophysiology Genesis of Benign Prostatic Hyperplasia and Prostate Cancer: A New Perspective

Background: The etiology of benign prostatic hyperplasia and prostate cancer are unknown, with ageing being the greatness risk factor. Methods: This new perspective evaluates the available interdisciplinary evidence regarding prostate ageing in terms of the cell biology of regulation and homeostasis, which could explain the timeline of evolutionary cancer biology as degenerative, inflammatory and neoplasm progressions in these multifactorial and heterogeneous prostatic diseases. Results: This prostate ageing degeneration hypothesis encompasses the testosterone-vascular-inflamm-ageing triad, along with the cell biology regulation of amyloidosis and autophagy within an evolutionary tumorigenesis microenvironment. Conclusions: An understanding of these biological processes of prostate ageing can provide potential strategies for early prevention and could contribute to maintaining quality of life for the ageing individual along with substantial medical cost savings.

Cannabinoids and myocardial ischemia: Novel insights, updated mechanisms, and implications for myocardial infarction

Cannabis is the most widely trafficked and abused illicit drug due to its calming psychoactive properties. It has been increasingly recognized as having potential health benefits and relatively less adverse health effects as compared to other illicit drugs; however, growing evidence clearly indicates that cannabis is associated with considerable adverse cardiovascular events. Recent studies have linked cannabis use to myocardial infarction (MI); yet, very little is known about the underlying mechanisms. A MI is a cardiovascular disease characterized by a mismatch in the oxygen supply and demand of the heart, resulting in ischemia and subsequent necrosis of the myocardium. Since cannabis is increasingly being considered a risk factor for MI, there is a growing need for better appreciating its potential health benefits and consequences. Here, we discuss the cellular mechanisms of cannabis that lead to an increased risk of MI. We provide a thorough and critical analysis of cannabinoids' actions, which include modulation of adipocyte biology, regional fat distribution, and atherosclerosis, as well as precipitation of hemodynamic stressors relevant in the setting of a MI. By critically dissecting the modulation of signaling pathways in multiple cell types, this paper highlights the mechanisms through which cannabis may trigger life-threatening cardiovascular events. This then provides a framework for future pharmacological studies which can identify targets or develop drugs that modulate cannabis' effects on the cardiovascular system as well as other organ systems. Cannabis' impact on the autonomic outflow, vascular smooth muscle cells, myocardium, cortisol levels and other hemodynamic changes are also mechanistically reviewed.

Reactive Oxygen Species: Modulators of Phenotypic Switch of Vascular Smooth Muscle Cells

Reactive oxygen species (ROS) are natural byproducts of oxygen metabolism in the cell. At physiological levels, they play a vital role in cell signaling. However, high ROS levels cause oxidative stress, which is implicated in cardiovascular diseases (CVD) such as atherosclerosis, hypertension, and restenosis after angioplasty. Despite the great amount of research conducted to identify the role of ROS in CVD, the image is still far from being complete. A common event in CVD pathophysiology is the switch of vascular smooth muscle cells (VSMCs) from a contractile to a synthetic phenotype. Interestingly, oxidative stress is a major contributor to this phenotypic switch. In this review, we focus on the effect of ROS on the hallmarks of VSMC phenotypic switch, particularly proliferation and migration. In addition, we speculate on the underlying molecular mechanisms of these cellular events. Along these lines, the impact of ROS on the expression of contractile markers of VSMCs is discussed in depth. We conclude by commenting on the efficiency of antioxidants as CVD therapies.

Flavonoids in adipose tissue inflammation and atherosclerosis: one arrow, two targets

Flavonoids are polyphenolic compounds naturally occurring in fruits and vegetables, in addition to beverages such as tea and coffee. Flavonoids are emerging as potent therapeutic agents for cardiovascular as well as metabolic diseases. Several studies corroborated an inverse relationship between flavonoid consumption and cardiovascular disease (CVD) or adipose tissue inflammation (ATI). Flavonoids exert their anti-atherogenic effects by increasing nitric oxide (NO), reducing reactive oxygen species (ROS), and decreasing pro-inflammatory cytokines. In addition, flavonoids alleviate ATI by decreasing triglyceride and cholesterol levels, as well as by attenuating inflammatory mediators. Furthermore, flavonoids inhibit synthesis of fatty acids and promote their oxidation. In this review, we discuss the effect of the main classes of flavonoids, namely flavones, flavonols, flavanols, flavanones, anthocyanins, and isoflavones, on atherosclerosis and ATI. In addition, we dissect the underlying molecular and cellular mechanisms of action for these flavonoids. We conclude by supporting the potential benefit for flavonoids in the management or treatment of CVD; yet, we call for more robust clinical studies for safety and pharmacokinetic values.

The Role of Epac in Cancer Progression

Cancer continues to be a prime contributor to global mortality. Despite tremendous research efforts and major advances in cancer therapy, much remains to be learned about the underlying molecular mechanisms of this debilitating disease. A better understanding of the key signaling events driving the malignant phenotype of cancer cells may help identify new pharmaco-targets. Cyclic adenosine 3',5'-monophosphate (cAMP) modulates a plethora of biological processes, including those that are characteristic of malignant cells. Over the years, most cAMP-mediated actions were attributed to the activity of its effector protein kinase A (PKA). However, studies have revealed an important role for the exchange protein activated by cAMP (Epac) as another effector mediating the actions of cAMP. In cancer, Epac appears to have a dual role in regulating cellular processes that are essential for carcinogenesis. In addition, the development of Epac modulators offered new routes to further explore the role of this cAMP effector and its downstream pathways in cancer. In this review, the potentials of Epac as an attractive target in the fight against cancer are depicted. Additionally, the role of Epac in cancer progression, namely its effect on cancer cell proliferation, migration/metastasis, and apoptosis, with the possible interaction of reactive oxygen species (ROS) in these phenomena, is discussed with emphasis on the underlying mechanisms and pathways.

EPAC in Vascular Smooth Muscle Cells

Vascular smooth muscle cells (VSMCs) are major components of blood vessels. They regulate physiological functions, such as vascular tone and blood flow. Under pathological conditions, VSMCs undergo a remodeling process known as phenotypic switching. During this process, VSMCs lose their contractility and acquire a synthetic phenotype, where they over-proliferate and migrate from the tunica media to the tunica interna, contributing to the occlusion of blood vessels. Since their discovery as effector proteins of cyclic adenosine 3′,5′-monophosphate (cAMP), exchange proteins activated by cAMP (EPACs) have been shown to play vital roles in a plethora of pathways in different cell systems. While extensive research to identify the role of EPAC in the vasculature has been conducted, much remains to be explored to resolve the reported discordance in EPAC’s effects. In this paper, we review the role of EPAC in VSMCs, namely its regulation of the vascular tone and phenotypic switching, with the likely involvement of reactive oxygen species (ROS) in the interplay between EPAC and its targets/effectors.

Bisphenols and phthalates: Plastic chemical exposures can contribute to adverse cardiovascular health outcomes

Phthalates and bisphenols are high production volume chemicals that are used in the manufacturing of consumer and medical products. Given the ubiquity of bisphenol and phthalate chemicals in the environment, biomonitoring studies routinely detect these chemicals in 75-90% of the general population. Accumulating evidence suggests that such chemical exposures may influence human health outcomes, including cardiovascular health. These associations are particularly worrisome for sensitive populations, including fetal, infant and pediatric groups-with underdeveloped metabolic capabilities and developing organ systems. In the presented article, we aimed to review the literature on environmental and clinical exposures to bisphenols and phthalates, highlight experimental work that suggests that these chemicals may exert a negative influence on cardiovascular health, and emphasize areas of concern that relate to vulnerable pediatric groups. Gaps in our current knowledge are also discussed, so that future endeavors may resolve the relationship between chemical exposures and the impact on pediatric cardiovascular physiology.

Estrogen and Bisphenol A in Hypertension

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is a non-subsiding disease that remains a leading cause of morbidity and mortality. CVD has been associated with endocrine disruptors, such as bisphenol A (BPA). This review critically summarizes existing findings on BPA and hypertension, with particular attention to genomic, non-genomic, molecular, and cellular mechanisms of action that render BPA as a cardiovascular estrogenic disruptor.

RECENT FINDINGS

Owing to its similar estrogenic structure, BPA has been shown to affect various phenotypes that are regulated by the natural hormone, estrogen. Indeed, BPA has been shown to interact with estrogen receptors, located both in the cell membrane and in the cytoplasm/nucleus. Given that estrogen plays an important role in cardiovascular physiology, a contributing role for BPA in CVD would not be unexpected. Existing literature, though limited, established BPA as a source of disruption in cardiovascular health, particularly hypertension. However, effects of BPA are largely dependent on the dose, patient gender, tissue, and developmental stage of the exposed tissue/organ. Accumulating evidence argues for an adverse effect of BPA on blood pressure, with this effect being gender, dose, and time specific. Thus, comprehensive studies which take these factors and other parameters, like epigenetic factors, into account are warranted before a thorough understanding is at hand.