Estrogen receptor alpha gene variation and the risk of stroke

Association of Estrogen Receptor-α and Aryl Hydrocarbon Receptor Gene Polymorphisms with Ischemic Stroke in an Egyptian Population: A Pilot Study

Stroke is the second leading cause of death and a major contributor to disability worldwide, with the highest prevalence in developing countries. Ischemic stroke (IS) is a complex disease resulting from genetic and environmental interactions. The present work is a pilot study exploring the association of estrogen receptor-α (ESR1) and aryl hydrocarbon receptor (AHR) SNPs with IS in a small Egyptian population of IS patients. Sixty IS patients and 60 matched healthy controls were included in this case-control study. Genotyping of ESR1 PvuII (rs2234693), ESR1 XbaI (rs9340799), and AHR rs2066853 SNPs was performed using real-time PCR. ESR1 PvuII TC and CC genotypes were associated with IS (odds ratio (OR) = 2.821, 95% confidence interval (CI) = 1.204-6.609, p = 0.017, and OR = 9.455, 95% CI = 2.222-40.237, p = 0.002, respectively), and TC genotype in female IS (OR = 4.018, 95% CI = 1.117-14.455, p = 0.033). Additionally, ESR1 XbaI GA and GG genotypes were associated with IS (OR = 2.833, 95% CI = 1.190-6.749, p = 0.019, and OR = 34.000, 95% CI = 6.965-165.980, p < 0.001, respectively), and the AG and GG genotypes in male IS (OR = 3.378, 95% CI = 1.103-10.347, p = 0.033 and OR = 22.8, 95% CI = 2.580-201.488, p = 0.005, respectively) and the GG genotype in female IS (95% CI = 7.259-1115.914, p < 0.001). ESR1 PvuII and XbaI haplotypes C-A, T-G, and C-A increased the risk of IS in both genders, in male IS, and in female IS apart from C-A. The AG genotype of AHR rs2066853 was associated with male IS (OR = 6.900, 95% CI = 2.120-22.457 p = 0.001). ESR1 PvuII, ESR1 XbaI, and AHR rs2066853 SNPs are associated with IS in Egyptians. However, this is a small sample, and the findings should be replicated in a larger population.

Unraveling Mechanisms of Cryptogenic Stroke at the Genetic Level: A Systematic Literature Review

Background A substantial proportion of ischemic strokes remain cryptogenic, which has important implications for secondary prevention. Identifying genetic variants related to mechanisms of stroke causes may provide a chance to clarify the actual causes of cryptogenic strokes. Methods and Results In a 2-step process, 2 investigators independently and systematically screened studies that reported genetic variants in regard to stroke causes that were published between January 1991 and April 2021. Studies on monogenetic disorders, investigation of vascular risk factors as the primary end point, reviews, meta-analyses, and studies not written in English were excluded. We extracted information on study types, ancestries, corresponding single nucleotide polymorphisms, and sample and effect sizes. There were 937 studies screened, and 233 were eligible. We identified 35 single nucleotide polymorphisms and allele variants that were associated with an overlap between cryptogenic strokes and another defined cause. Conclusions Associations of single variants with an overlap between cryptogenic stroke and another defined cause were limited to a few polymorphisms. A limitation of all studies is a low granularity of clinical data, which is of major importance in a complex disease such as stroke. Deep phenotyping is in supposed contradiction with large sample sizes but needed for genome-wide analyses. Future studies should attempt to address this restriction to advance the promising approach of elucidating the cause of stroke at the genetic level. Especially in a highly heterogenous disease such as ischemic stroke, genetics are promising to establish a personalized approach in diagnostics and treatment in the sense of precision medicine.

Long-term oral administration of a novel estrogen receptor beta agonist enhances memory and alleviates drug-induced vasodilation in young ovariectomized mice

Development of estrogen therapies targeting the β (ERβ) but not α (ERα) estrogen receptor is critically needed for the treatment of negative menopausal symptoms, as ERα activation increases health risks like cancer. Here, we determined the effects of long-term oral treatment with EGX358, a novel highly selective ERβ agonist, on memory, vasodilation, and affect in young ovariectomized mice. Mice were orally gavaged daily for 9 weeks with vehicle, 17β-estradiol (E₂), the ERβ agonist diarylpropionitrile (DPN), or EGX358 at doses that enhance memory when delivered acutely. Tail skin temperature was recorded as a proxy for vasodilation following injection of vehicle or senktide, a tachykinin receptor 3 agonist used to model hot flashes. Anxiety-like behavior was assessed in the open field (OF) and elevated plus maze (EPM), and depression-like behavior was measured in the tail suspension (TST) and forced swim tests (FST). Finally, memory was assessed in object recognition (OR) and object placement (OP) tasks. E₂, DPN, and EGX358 reduced senktide-mediated increases in tail skin temperature compared to vehicle. All three treatments also enhanced memory in the OR and OP tasks, whereas vehicle did not. Although E₂ increased time spent in the center of the OF, no other treatment effects were observed in the OF, EPM, TST, or FST. These data suggest that long-term ERβ activation can reduce hot flash-like symptoms and enhance spatial and object recognition memories in ovariectomized mice. Thus, the highly selective ERβ agonist EGX358 may be a promising avenue for reducing menopause-related hot flashes and memory dysfunction.

ESR1 polymorphisms and risk of preeclampsia

OBJECTIVE

Polymorphism of estrogen receptor α (ESR1) polymorphisms plays an important role in the adaptation of increased uterine blood flow during gestation. Published data on the association between the ESR1 polymorphisms and preeclampsia risk are controversial. A meta-analysis was performed to assess whether the polymorphisms of ESR1 are associated with preeclampsia risk.

METHODS

Medline, Embase, China National Knowledge Infrastructure, and Chinese Biomedicine Databases were searched to identify eligible studies. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for ESR1 polymorphisms and preeclampsia were appropriately derived from fixed-effects or random-effects models.

RESULTS

A total of seven studies were enrolled in this meta-analysis. The pooled analyses revealed that both ESR1 PvuII and XbaI polymorphisms were not associated with preeclampsia risk. No significant heterogeneity among the including studies was found in all models of ESR1 PvuII and XbaI polymorphisms.

CONCLUSIONS

Present meta-analysis demonstrates that ESR1 polymorphisms may not be correlated to preeclampsia risk.

Sex, Gender, and Sex Hormones in Pulmonary Hypertension and Right Ventricular Failure

Pulmonary hypertension (PH) encompasses a syndrome of diseases that are characterized by elevated pulmonary artery pressure and pulmonary vascular remodeling and that frequently lead to right ventricular (RV) failure and death. Several types of PH exhibit sexually dimorphic features in disease penetrance, presentation, and progression. Most sexually dimorphic features in PH have been described in pulmonary arterial hypertension (PAH), a devastating and progressive pulmonary vasculopathy with a 3-year survival rate <60%. While patient registries show that women are more susceptible to development of PAH, female PAH patients display better RV function and increased survival compared to their male counterparts, a phenomenon referred to as the "estrogen paradox" or "estrogen puzzle" of PAH. Recent advances in the field have demonstrated that multiple sex hormones, receptors, and metabolites play a role in the estrogen puzzle and that the effects of hormone signaling may be time and compartment specific. While the underlying physiological mechanisms are complex, unraveling the estrogen puzzle may reveal novel therapeutic strategies to treat and reverse the effects of PAH/PH. In this article, we (i) review PH classification and pathophysiology; (ii) discuss sex/gender differences observed in patients and animal models; (iii) review sex hormone synthesis and metabolism; (iv) review in detail the scientific literature of sex hormone signaling in PAH/PH, particularly estrogen-, testosterone-, progesterone-, and dehydroepiandrosterone (DHEA)-mediated effects in the pulmonary vasculature and RV; (v) discuss hormone-independent variables contributing to sexually dimorphic disease presentation; and (vi) identify knowledge gaps and pathways forward. © 2020 American Physiological Society. Compr Physiol 10:125-170, 2020.

The Association of Estrogen Receptor-β Gene Variation With Salt-Sensitive Blood Pressure

CONTEXT

Hypertension in young women is uncommon compared with young men and older women. Estrogen appears to protect most women against hypertension, with incidence increasing after menopause. Because some premenopausal women develop hypertension, estrogen may play a different role in these women. Genetic variations in the estrogen receptor (ER) are associated with cardiovascular disease. ER-β, encoded by ESR2, is the ER predominantly expressed in vascular smooth muscle.

OBJECTIVE

To determine an association of single nucleotide polymorphisms in ESR2 with salt sensitivity of blood pressure (SSBP) and estrogen status in women.

METHODS

Candidate gene association study with ESR2 and SSBP conducted in normotensive and hypertensive women and men in two cohorts: International Hypertensive Pathotype (HyperPATH) (n = 584) (discovery) and Mexican American Hypertension-Insulin Resistance Study (n = 662) (validation). Single nucleotide polymorphisms in ESR1 (ER-α) were also analyzed. Analysis conducted in younger (<51 years, premenopausal, "estrogen-replete") and older women (≥51 years, postmenopausal, "estrogen-deplete"). Men were analyzed to control for aging.

RESULTS

Multivariate analyses of HyperPATH data between variants of ESR2 and SSBP documented that ESR2 rs10144225 minor (risk) allele carriers had a significantly positive association with SSBP driven by estrogen-replete women (β = +4.4 mm Hg per risk allele, P = 0.004). Findings were confirmed in Hypertension Insulin-Resistance Study premenopausal women. HyperPATH cohort analyses revealed risk allele carriers vs noncarriers had increased aldosterone/renin ratios. No associations were detected with ESR1.

CONCLUSIONS

The variation at rs10144225 in ESR2 was associated with SSBP in premenopausal women (estrogen-replete) and not in men or postmenopausal women (estrogen-deplete). Inappropriate aldosterone levels on a liberal salt diet may mediate the SSBP.

The effects of oestrogens and their receptors on cardiometabolic health

Cardiovascular disease (CVD) is one of the leading causes of mortality in developed countries. The incidence of CVD is sexually dimorphic, and research has focused on the contribution of sex steroids to the development and progression of the cardiometabolic syndrome, which is defined as a clustering of interrelated risk factors that promote the development of atherosclerosis (which can lead to CVD) and type 2 diabetes mellitus. Data are inconclusive as to how sex steroids and their respective receptors increase or suppress the risk of developing the cardiometabolic syndrome and thus CVD. In this Review, we discuss the potential role, or roles, of sex hormones in cardiometabolic health by first focusing on the influence of oestrogens and their receptors on the risk of developing cardiometabolic syndrome and CVD. We also highlight what is known about testosterone and its potential role in protecting against the development of the cardiometabolic syndrome and CVD. Given the inconclusive nature of the data regarding the direct effects of each sex hormone, we advocate and highlight the importance of studying the relative levels and the ratio of sex hormones to each other, as well as the use of cross sex hormone therapy and its effect on cardiometabolic health.

Sex Hormones and Cardiometabolic Health: Role of Estrogen and Estrogen Receptors

With increased life expectancy, women will spend over three decades of life postmenopause. The menopausal transition increases susceptibility to metabolic diseases such as obesity, diabetes, cardiovascular disease, and cancer. Thus, it is more important than ever to develop effective hormonal treatment strategies to protect aging women. Understanding the role of estrogens, and their biological actions mediated by estrogen receptors (ERs), in the regulation of cardiometabolic health is of paramount importance to discover novel targeted therapeutics. In this brief review, we provide a detailed overview of the literature, from basic science findings to human clinical trial evidence, supporting a protective role of estrogens and their receptors, specifically ERα, in maintenance of cardiometabolic health. In so doing, we provide a concise mechanistic discussion of some of the major tissue-specific roles of estrogens signaling through ERα. Taken together, evidence suggests that targeted, perhaps receptor-specific, hormonal therapies can and should be used to optimize the health of women as they transition through menopause, while reducing the undesired complications that have limited the efficacy and use of traditional hormone replacement interventions.

microRNA profiling in atherosclerosis, diabetes, and migraine

microRNAs (miRNAs) are a broad group of endogenous small non-coding molecules that reduce the transcription of mRNA and play a key role in post-transcriptional gene processes. miRNAs are involved in onset and progression of several human disorders such as infectious and immune non-infectious diseases, cancers, metabolic and cardiovascular disorders. They regulate the expression of gene targets (e.g. oncogenes and tumor suppressor genes) and act as gene repressors with mRNA binding and cleavage. The increasing evidence that miRNAs play a key role in the pathogenesis of cardiovascular conditions could radically change the future management approach to these disorders. This review focuses on current knowledge about the influence of miRNAs on cardiovascular disease, with particular regard to common conditions such as atherosclerosis, diabetes and migraine. Key messages miRNAs are a group of endogenous small non-coding RNA segments measuring 19-25 nucleotides that are involved in physiologic processes and onset and progression of disorders such as infectious and immune non-infectious diseases, cancers, metabolic and cardiovascular disorders. miRNAs expression guarantees vascular integrity, by regulating apoptosis, VEGF pathway and VCAM 1 expression (-126), and is involved in atherosclerotic plaque formation process and progression. Hyperglycemia, overt diabetes, and their complications are associated with overexpression of several miRNAs. An altered expression of miRNAs has also been postulated in migraine patients, although only a few preliminary studies have so far been performed with this respect.

The Impact of Gonadal Hormones on the Expression of Human Neurological Disorders

The effects of gonadal steroids on neurological well-being and disease constitute a rich and rapidly expanding area of basic and clinical neuroscience. Gonadal hormones exert potent effects on monoaminergic, cholinergic and peptidergic pathways as well as neurosteroidogenesis which, in turn, impact normal brain organization and function. A spectrum of human neurological conditions are influenced by hormonal fluctuations associated with the menstrual cycle, pregnancy, the menopause and use of oral contraceptives. An appreciation of these relationships may facilitate the development of specific hormonal and anti-hormonal therapies for neurological disorders as disparate as catamenial epilepsy and acute intermittent porphyria.

Genetic polymorphism of estrogen receptor alpha gene in Egyptian women with type II diabetes mellitus

Estrogen might play an important role in type 2 diabetes mellitus pathogenesis. A number of polymorphisms have been reported in the estrogen receptor alpha gene including the XbaI and PvuII restriction enzyme polymorphisms. The aim of this study was to determine if ESRα gene polymorphisms are associated with type 2 diabetes mellitus and correlated with lipid profile. Ninety diabetic Egyptian patients were compared with forty healthy controls. ESRα genotyping of PvuII and XbaI was performed using restriction fragment length polymorphism analysis. Our study showed that there is more significant difference in the frequency of C and G polymorphic allele between patients and control groups in PvuII and XbaI respectively. Also carriers of minor C and G alleles of PvuII and XbaI gene polymorphisms were associated with increased fasting blood glucose and disturbance in lipid profile as there is an increase in total cholesterol, triglycerides and Low density lipoprotein. So findings of present study suggest the possibility that PvuII and XbaI polymorphisms in ERα are related to T2DM and with increased serum lipids among Egyptian population.

MicroRNA profiling in migraine without aura: pilot study

BACKGROUND AND PURPOSE

MicroRNAs (miRNAs) are short, non-coding RNAs whose deregulation has been shown in several human diseases, including pain states and diseases associated with increased cardiovascular (CV) risk. This study aimed at identifying differentially expressed circulating miRNAs in patients with 'migraine without aura' (MO), a pain condition whose link with CV risk remains debated.

METHODS

Fifteen female MO patients and 13 matching healthy controls underwent a circulating microRNA expression profiling. MiR-22, miR-26a, miR-26b, miR-27b, miR-29b, let-7b, miR-181a, miR-221, miR-30b, and miR-30e were selected for validation by quantitative real-time polymerase chain reaction.

RESULTS

In migraineurs versus controls, four miRNAs were differentially expressed: miR-27b was significantly up-regulated (q < 0.004), while miR-181a, let-7b, and miR-22 were significantly down-regulated (q ≤ 0.01). MiR-22 and let-7b down-regulation was also confirmed in circulating blood monocytes. A logistic regression model based on microRNA expression profile showed a high accuracy for identifying migraine (AUC of ROC curve: 0.956; P < 0.001).

CONCLUSION

A specific circulating miRNAs profile is associated with migraine without aura. Remarkably, the same miRNAs are known to be modulated in the setting of atherosclerosis and stroke in humans. This study represents a first step towards further characterization of MO diagnosis/pathophysiology, also in relation to its link with cardiovascular risk.

Progress in solving the sex hormone paradox in pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a devastating and progressive disease with marked morbidity and mortality. Even though being female represents one of the most powerful risk factors for PAH, multiple questions about the underlying mechanisms remain, and two "estrogen paradoxes" in PAH exist. First, it is puzzling why estrogens have been found to be protective in various animal models of PAH, whereas PAH registries uniformly demonstrate a female susceptibility to the disease. Second, despite the pronounced tendency for the disease to develop in women, female PAH patients exhibit better survival than men. Recent mechanistic studies in classical and in novel animal models of PAH, as well as recent studies in PAH patients, have significantly advanced the field. In particular, it is now accepted that estrogen metabolism and receptor signaling, as well as estrogen interactions with key pathways in PAH development, appear to be potent disease modifiers. A better understanding of these interactions may lead to novel PAH therapies. It is the purpose of this review to 1) review sex hormone synthesis, metabolism, and receptor physiology; 2) assess the context in which sex hormones affect PAH pathogenesis; 3) provide a potential explanation for the observed estrogen paradoxes and gender differences in PAH; and 4) identify knowledge gaps and future research opportunities. Because the majority of published studies investigated 17β-estradiol and/or its metabolites, this review will primarily focus on pulmonary vascular and right ventricular effects of estrogens. Data for other sex hormones will be discussed very briefly.

Genetic polymorphisms in the ESR1 gene and cerebral infarction risk: a meta-analysis

A number of studies have documented that estrogen receptor α (ESR1) may play an important role in the development and progression of cerebral infarction, but many existing studies have yielded inconclusive results. This meta-analysis was performed to evaluate the relationships between ESR1 genetic polymorphisms and cerebral infarction risk. The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched for relevant articles published before October 1, 2013, without any language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Seven case-control studies were included with a total of 1471 patients with cerebral infarction and 4688 healthy control subjects. Two common single-nucleotide polymorphisms (SNPs) in the ESR1 gene (rs2234693 T>C and rs9340799 A>G) were assessed. Our meta-analysis results revealed that ESR1 genetic polymorphisms might increase the risk of cerebral infarction. Subgroup analysis by SNP type indicated that both rs2234693 and rs9340799 polymorphisms in the ESR1 gene were strongly associated with an increased risk of cerebral infarction. Further subgroup analysis by ethnicity showed significant associations between ESR1 genetic polymorphisms and increased risk of cerebral infarction among both Asians and Caucasians. In the stratified subgroup analysis by gender, the results suggested that ESR1 genetic polymorphisms were associated with an increased risk of cerebral infarction in the female population. However, there were no statistically significant associations between ESR1 genetic polymorphisms and cerebral infarction risk in the male population. Meta-regression analyses also confirmed that gender might be a main source of heterogeneity. Our findings indicate that ESR1 genetic polymorphisms may contribute to the development of cerebral infarction, especially in the female population.

A study of ERα PvuII polymorphism in female patients with acute stroke: no associations with disease severity and early outcome

Several studies have examined the association of the PvuII polymorphism of the estrogen receptor alpha gene with the risk of stroke. Data linking the polymorphism with the severity and outcome of cerebrovascular disease are lacking. In this study, we evaluated 285 postmenopausal Caucasian patients suffering an acute stroke, hospitalized in two tertiary hospitals over a period of 2 years, and searched for associations between the PvuII polymorphism and the one-month outcome and the neurological severity on admission. The prevalence of CC genotype was 21%, CT 50% and TT 29%. Estradiol levels were higher with increasing frequencies of the C allele (p = 0.04). There was no difference in the short-term functional outcome and mortality and the neurological severity on admission among the three genotypes. We did not find a significant association of the PvuII polymorphism with intracerebral hemorrhage and classical stroke risk factors. An association of the CC genotype with venous thromboembolism history was recorded (p 0.05). There was no association between the PvuII polymorphism and stroke severity and short-term outcome in the studied female stroke population. It is possible that the long-term estrogenic action, reflected by the genetic polymorphism, is not a major determinant of disease severity and prognosis in older age.

Gender, sex hormones and pulmonary hypertension

Most subtypes of pulmonary arterial hypertension (PAH) are characterized by a greater susceptibility to disease among females, although females with PAH appear to live longer after diagnosis. While this "estrogen paradoxȍ of enhanced female survival despite increased female susceptibility remains a mystery, recent progress has begun to shed light upon the interplay of sex hormones, the pathogenesis of pulmonary hypertension, and the right ventricular response to stress. For example, emerging data in humans and experimental models suggest that estrogens or differential sex hormone metabolism may modify disease risk among susceptible subjects, and that estrogens may interact with additional local factors such as serotonin to enhance the potentially damaging chronic effects of estrogens on the pulmonary vasculature. Regardless, it remains unclear why not all estrogenic compounds behave equally, nor why estrogens appear to be protective in certain settings but detrimental in others. The contribution of androgens and other compounds, such as dehydroepiandrosterone, to pathogenesis and possibly treatment must be considered as well. In this review, we will discuss the recent understandings on how estrogens, estrogen metabolism, dehydroepiandrosterone, and additional susceptibility factors may all contribute to the pathogenesis or potentially to the treatment of pulmonary hypertension, by evaluating current human, cell-based, and experimental model data.

Analysis of sex hormone genes reveals gender differences in the genetic etiology of blood pressure salt sensitivity: the GenSalt study

BACKGROUND

We examined the association between 799 single-nucleotide polymorphisms in 39 sex hormone genes and blood pressure (BP) responses to a dietary-sodium intervention.

METHODS

A 7-day low-sodium feeding study (51.3 mmol sodium/day) followed by a 7-day high-sodium feeding study (307.8 mmol sodium/day) was conducted among 1,906 Han Chinese participants. Nine BP measurements were obtained at baseline and the end of each intervention period using a random-zero sphygmomanometer.

RESULTS

Among men, absolute BP responses to sodium interventions decreased with the number of minor alleles of estrogen receptor 1 (ESR1) markers rs9340844, rs9397453, rs9371562, rs9397459, and rs9383951. For example, mean diastolic blood pressure (DBP) responses to low-sodium intervention (95% confidence interval) were -2.67 (-3.13, -2.22) mm Hg among those with the rs9397453 C/C genotype, -1.23 (-1.98, -0.48) mm Hg among those with the C/T genotype, and 0.08 (-2.31, 2.47) mm Hg among those with the T/T genotype (P = 1×10(-4); false discovery rate (FDR)-q = 0.04). Mean DBP responses to high sodium according to the rs9397453 genotypes were 1.46 (1.03, 1.89) mm Hg among those with C/C, 0.19 (-0.54, 0.91) mm Hg among those with C/T, and -1.10 (-2.82, 0.61) mm Hg among those with T/T (P = 2×10(-4); FDR-q = 0.04). Similar trends were noted for the association between these ESR1 variants and SBP responses to the dietary intervention. There were no significant associations between sex hormone gene variants and salt sensitivity in women, with genotype-gender interactions noted for the ESR1 markers that achieved significance in men.

CONCLUSIONS

We identified strong, consistent associations between ESR1 gene variants and salt sensitivity in men. Our results support a gender-specific role for ESR1 in the etiology of this complex trait.

Epistasis analysis for estrogen metabolic and signaling pathway genes on young ischemic stroke patients

Background

Endogenous estrogens play an important role in the overall cardiocirculatory system. However, there are no studies exploring the hormone metabolism and signaling pathway genes together on ischemic stroke, including sulfotransferase family 1E (SULT1E1), catechol-O-methyl-transferase (COMT), and estrogen receptor α (ESR1).

Methods

A case-control study was conducted on 305 young ischemic stroke subjects aged ≦ 50 years and 309 age-matched healthy controls. SULT1E1 -64G/A, COMT Val158Met, ESR1 c.454−397 T/C and c.454−351 A/G genes were genotyped and compared between cases and controls to identify single nucleotide polymorphisms associated with ischemic stroke susceptibility. Gene-gene interaction effects were analyzed using entropy-based multifactor dimensionality reduction (MDR), classification and regression tree (CART), and traditional multiple regression models.

Results

COMT Val158Met polymorphism showed a significant association with susceptibility of young ischemic stroke among females. There was a two-way interaction between SULT1E1 -64G/A and COMT Val158Met in both MDR and CART analysis. The logistic regression model also showed there was a significant interaction effect between SULT1E1 -64G/A and COMT Val158Met on ischemic stroke of the young (P for interaction = 0.0171). We further found that lower estradiol level could increase the risk of young ischemic stroke for those who carry either SULT1E1 or COMT risk genotypes, showing a significant interaction effect (P for interaction = 0.0174).

Conclusions

Our findings support that a significant epistasis effect exists among estrogen metabolic and signaling pathway genes and gene-environment interactions on young ischemic stroke subjects.

17β-Estradiol attenuates hypoxic pulmonary hypertension via estrogen receptor-mediated effects

RATIONALE

17β-Estradiol (E2) attenuates hypoxic pulmonary vasoconstriction and hypoxic pulmonary hypertension (HPH) through an unknown mechanism that may involve estrogen receptors (ER) or E2 conversion to catecholestradiols and methoxyestradiols with previously unrecognized effects on cardiopulmonary vascular remodeling.

OBJECTIVES

To determine the mechanism by which E2 exerts protective effects in HPH.

METHODS

Male rats were exposed to hypobaric hypoxia while treated with E2 (75 μg/kg/d) or vehicle. Subgroups were cotreated with pharmacologic ER-antagonist or with inhibitors of E2-metabolite conversion. Complementary studies were performed in rats cotreated with selective ERα- or ERβ-antagonist. Hemodynamic and pulmonary artery (PA) and right ventricular (RV) remodeling parameters, including cell proliferation, cell cycle, and autophagy, were measured in vivo and in cultured primary rat PA endothelial cells.

MEASUREMENTS AND MAIN RESULTS

E2 significantly attenuated HPH endpoints. Hypoxia increased ERβ but not ERα lung vascular expression. Co-treatment with nonselective ER inhibitor or ERα-specific antagonist rendered hypoxic animals resistant to the beneficial effects of E2 on cardiopulmonary hemodynamics, whereas ERα- and ERβ-specific antagonists opposed the remodeling effects of E2. In contrast, inhibition of E2-metabolite conversion did not abolish E2 protection. E2-treated hypoxic animals exhibited reduced ERK1/2 activation and increased expression of cell-cycle inhibitor p27(Kip1) in lungs and RV, with up-regulation of lung autophagy. E2-induced signaling was recapitulated in hypoxic but not normoxic endothelial cells, and was associated with decreased vascular endothelial growth factor secretion and cell proliferation.

CONCLUSIONS

E2 attenuates hemodynamic and remodeling parameters in HPH in an ER-dependent manner, through direct antiproliferative mechanisms on vascular cells, which may provide novel nonhormonal therapeutic targets for HPH.

Effect of hormone therapy and calcitriol on serum lipid profile in postmenopausal older women: association with estrogen receptor-α genotypes

OBJECTIVE

The aim of this study was to examine the effect of conjugated equine estrogens alone (ET), conjugated equine estrogens + medroxyprogesterone (EPT), calcitriol alone, calcitriol + EPT/ET, or placebo on serum lipid profile and analyze the interaction with estrogen receptor-α gene single nucleotide polymorphisms (ESR-α SNPs) on the response to therapy.

METHODS

A total of 489 postmenopausal women older than 65 years were enrolled into a 3-year double-blind, placebo-controlled clinical trial.

RESULTS

In both intent-to-treat and complier (>80% adherent) analysis, there was a significant increase in serum high-density lipoproteins and a significant decrease in serum low-density lipoproteins (LDLs) and the LDL/high-density lipoprotein ratio in all hormone treatment groups compared with placebo (P < 0.05). However, serum triglycerides and very low-density lipoproteins increased in the EPT and ET + calcitriol groups versus placebo (P < 0.05). ESR-α SNPs PvuII and XbaI seemed to have a significant effect on the response to treatment. Genotypes containing the p allele showed a significantly greater decrease in serum cholesterol and very low-density lipoprotein than those having the P allele in the ET + calcitriol group (P < 0.05), and those with the x allele had a significantly greater decrease in serum cholesterol in the hormone therapy + calcitriol group at the end of 3 years versus the X allele, and a greater decrease in serum LDL in alleles x versus the X in the ET + calcitriol group (P < 0.05).

CONCLUSIONS

ET with or without progesterone had a favorable effect on lipid profile in postmenopausal older women, and this was dependent on estrogen receptor SNPs--PvuII and XbaI. However, this interaction with ESR-α SNPs needs to be confirmed in larger studies.

Hypogonadism as a risk factor for cardiovascular mortality in men: a meta-analytic study

OBJECTIVE

To verify whether hypogonadism represents a risk factor for cardiovascular (CV) morbidity and mortality and to verify whether testosterone replacement therapy (TRT) improves CV parameters in subjects with known CV diseases (CVDs).

DESIGN

Meta-analysis.

METHODS

An extensive Medline search was performed using the following words 'testosterone, CVD, and males'. The search was restricted to data from January 1, 1969, up to January 1, 2011.

RESULTS

Of the 1178 retrieved articles, 70 were included in the study. Among cross-sectional studies, patients with CVD have significantly lower testosterone and higher 17-β estradiol (E(2)) levels. Conversely, no difference was observed for DHEAS. The association between low testosterone and high E(2) levels with CVD was confirmed in a logistic regression model, after adjusting for age and body mass index (hazard ratio (HR)=0.763 (0.744-0.783) and HR=1.015 (1.014-1.017), respectively, for each increment of total testosterone and E(2) levels; both P<0.0001). Longitudinal studies showed that baseline testosterone level was significantly lower among patients with incident overall- and CV-related mortality, in comparison with controls. Conversely, we did not observe any difference in the baseline testosterone and E(2) levels between case and controls for incident CVD. Finally, TRT was positively associated with a significant increase in treadmill test duration and time to 1 mm ST segment depression.

CONCLUSIONS

Lower testosterone and higher E(2) levels correlate with increased risk of CVD and CV mortality. TRT in hypogonadism moderates metabolic components associated with CV risk. Whether low testosterone is just an association with CV risk, or an actual cause-effect relationship, awaits further studies.

Free protein S level as a risk factor for coronary heart disease and stroke in a prospective cohort study of healthy United Kingdom men

Plasma protein S (PS) levels are reportedly low in patients with venous thrombosis but high in coronary heart disease (CHD) patients. The authors examined the association between free PS concentration and CHD or stroke risk and assessed risk in combination with C-reactive protein (CRP) levels. Free PS concentration was determined in 6 annual visits among 3,052 middle-aged (49-64 years) United Kingdom men from the Second Northwick Park Heart Study, with 297 CHD events from 1989 to 2005. The highest (vs. first) quintile was associated with a significantly increased CHD risk after adjustment for all other risk factors and correction for regression dilution bias (hazard ratio = 1.85, 95% confidence interval: 1.08, 3.16; P = 0.024). Models that included all well-known risk factors plus PS quintiles improved prediction of CHD (net reclassification improvement (NRI) = 7.0% (P = 0.007), category-less NRI (>0) = 22.1% (P < 0.001)), and the likelihood ratio statistic increased significantly (P = 0.018). The increase in CHD risk was particularly strong when subjects also had high CRP levels. There was no association between free PS level and stroke risk. This study confirms the independent association of elevated free PS levels with future risk of CHD, although elevated PS levels added only modestly to prediction metrics. The novel finding of increased CHD risk, particularly when CRP and PS levels are high, requires further study.

Estrogen receptor alpha gene polymorphisms are associated with type 2 diabetes and fasting glucose in male subjects

The PvuII and XbaI polymorphisms of the estrogen receptor α (ER1) gene have been variably associated with type 2 diabetes (T2D) in several populations. However, this association has not been studied in Iranian subjects and we hypothesized that the ER1 variants might be associated with T2D and related metabolic traits in this population. The PvuII and XbaI genotypes were determined by PCR-RFLP in 377 normoglycemic controls and 155 T2D patients. Bonferroni correction was applied for the correction of multiple testing. No significant association was found between the allele and genotype frequencies of PvuII and XbaI variants with T2D in females. In a dominant model (PP vs. Pp+pp), the frequency of the Pp+pp genotype was higher in normoglycemic subjects compared to T2D patients [85.5% vs. 66.7%, OR 0.22 (0.08-0.55), P=0.001]. Four possible haplotypes were observed in the population, whereas haplotype TA had a higher frequency in male T2D subjects than the controls. Furthermore, non-diabetic male subjects carrying the genotype of PP had a higher fasting glucose levels than the individuals with the genotype of Pp+pp (P=0.013). Multivariate logistic regression analysis showed that PvuII polymorphism was the independent determinants of T2D in males [OR 4.37 (1.61-11.86), P=0.004]. No association was found between the XbaI polymorphism and diabetes in male group. Our results suggest that the ER1 polymorphisms might associate with T2D and fasting glucose among Iranian male subjects.

Genetics of menstrual migraine: the molecular evidence

Migraine is considered to be a multifactorial disorder in which genetic, environmental, and, in the case of menstrual and menstrually related migraine, hormonal events influence the phenotype. Certainly, the role of female sex hormones in migraine has been well established, yet the mechanism behind this well-known relationship remains unclear. This review focuses on the potential role of hormonally related genes in migraine, summarizes results of candidate gene studies to date, and discusses challenges and issues involved in interpreting hormone-related gene results. In light of the molecular evidence presented, we discuss future approaches for analysis with the view to elucidate the complex genetic architecture that underlies the disorder.

Sex-based differences in vascular function

Cardiovascular disease is the leading cause of morbidity and mortality for both men and women in the USA. However, there are differences between the sexes in age-dependent onset, severity, symptoms and outcomes. Basic research into the causes of sex-dependent differences in cardiovascular disease is ongoing and includes investigation into genetic variation in expression and distribution of receptors for the sex steroids; specificity of natural and synthetic ligands that activate the sex steroid receptors; and intracellular mechanisms that are activated by the receptors in all components of the vessel wall and blood elements, which integrate to regulate vascular tone, vascular repair and remodeling in health and disease. In this era of personalized medicine, basic research into mechanisms of sex differences in vascular function will result in improved prevention, detection and treatment of cardiovascular disease in both men and women.

Estrogen receptor polymorphisms and the vascular effects of hormone therapy

OBJECTIVE

To test whether estrogen receptor polymorphisms modify the effects of postmenopausal hormone therapy on biomarkers and on risk of coronary heart disease events, stroke, or venous thromboembolism.

METHODS AND RESULTS

The design was a nested case-control study in the Women's Health Initiative trials of postmenopausal hormone therapy. The study included all cases in the first 4 years: 359 cases of coronary heart disease, 248 of stroke, and 217 of venous thromboembolism. Six estrogen receptor-α polymorphisms and 1 estrogen receptor-β polymorphism were genotyped; 8 biomarkers known to be affected by hormone therapy were measured at baseline and 1 year after randomization. The polymorphisms were not associated with risk of vascular events and did not modify the increased risks of coronary heart disease, stroke, or venous thromboembolism due to hormone therapy. However, a reduced response of plasmin-antiplasmin to hormone therapy was noted for estrogen receptor-1 IVS1 (intron number 1)-354 (interaction P<0.0001, corrected for multiple comparisons P=0.014) and estrogen receptor-1 IVS1-1415 (interaction P<0.0001, corrected P=0.014).

CONCLUSIONS

Estrogen receptor polymorphisms reduce the effect of postmenopausal hormone therapy on plasmin-antiplasmin, a marker of coagulation and fibrinolysis. However, screening for estrogen receptor polymorphisms to identify women at less risk of adverse cardiovascular outcomes is not likely to be useful in making decisions about hormone therapy treatment.

Estrogen receptor α genetic variants and the risk of stroke in a South Indian population from Andhra Pradesh

BACKGROUND

Stroke is a complex disease caused by combination of multiple risk factors. Recent findings have suggested that stroke has a strong genetic component. Evidence suggests that variations in the estrogen receptor α (ESR1) gene may influence stroke risk.

AIMS

The present study was carried out to investigate the role of ESR1 gene polymorphisms [PvuII (rs 2234693) and XbaI (rs 9340799)] with stroke in a South Indian population from Andhra Pradesh. The relationship between ESR1 genotypes with estradiol levels was also investigated in pre- and postmenopausal women.

METHODS

Four hundred patients with ischemic stroke and three hundred and eighty subjects were enrolled in this case-control study. Ischemic stroke subtypes were classified according to TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification. The ESR1 PvuII and XbaI genotypes were determined by PCR-RFLP method. Serum estradiol was measured by ELISA.

RESULTS

In case of PvuII polymorphism statistically significant difference was observed in the genotypic and allelic frequencies between patients and controls (joint analysis of men and women) (p=0.003 and 0.004 respectively). However, the XbaI genotypes and alleles did not show an association with stroke in the study population. When the analysis was carried out separately for men and women, the PvuII polymorphism did not show significant association with stroke in men; women showed a significant association. Further when women were grouped in to premenopausal and postmenopausal, the premenopausal group did not show a significant association with the polymorphism but significant association with stroke was found in postmenopausal women. A stepwise multiple logistic regression analysis confirmed these findings. Women with pp genotype had low estradiol levels in comparison with PP genotypic individuals (p<0.05). Further evaluating the association of this polymorphism with stroke subtypes, we found significant association of PvuII polymorphism with extracranial atherosclerosis, lacunar and cardioembolic stroke.

CONCLUSION

In conclusion our results suggest the PvuII gene polymorphism is significantly associated with stroke in postmenopausal women in a South Indian population from Andhra Pradesh. The pp genotypes have average 17β estradiol levels which are significantly low in comparison with PP genotypes. Therefore postmenopausal women with a high frequency of pp genotype are more predisposed to ischemic stroke. However, this is a preliminary study and the results need to be confirmed in a larger cohort.

ESR1 genetic variants, haplotypes and the risk of coronary heart disease and ischemic stroke in the Finnish population: a prospective follow-up study

Association of estrogen receptor 1 (ESR1) gene variants and risk of coronary heart disease (CHD) and ischemic stroke was evaluated in the FINRISK-study. From 14,140 individuals, 2225 were selected for genotyping using a case-cohort design. Time-to-event analysis showed that the CC genotype of -397T/C ERS1 gene contributed to higher risk of CHD only in men (HR, 1.68, CI 1.03-2.74). The -351A/G polymorphism was not independently associated with CHD. Haplotype analysis of these two variants indicated that in men, haplotype TA conferred lower risk of CHD (HR=0.72, CI 0.55-0.95), whereas men with haplotype CA had 1.8 higher risk of CHD events (CI 1.21-2.77), compared to other haplotypes. No association was found with ischemic stroke. Our study suggests that the minor allele -397C of the ESR1 gene confers risk of CHD among Finnish men, both in homozygous state and as part of a haplotype with the -351A allele.

Association of estrogen receptor-alpha gene polymorphisms with cardiac autonomic nervous activity in healthy young Japanese males

BACKGROUND

Estrogens exert beneficial effects on the cardiovascular system that are mediated by estrogen receptors. We examined the association between the estrogen receptor alpha gene (ESR1) PvuII and XbaI polymorphisms and cardiac autonomic nervous function in Japanese males.

METHODS

We examined 252 young healthy males for association of ESR1 PvuII and XbaI polymorphisms and short-term heart rate variability (HRV) during supine rest and in a standing position. The very low frequency (VLF), low frequency (LF), and high frequency (HF) components of HRV were quantified by frequency domain analysis.

RESULTS

Carriers of the ESR1 PvuII C allele had higher mean blood pressure (BP), while the XbaI GG genotype was significantly associated with higher diastolic and mean BP, but lower HR. In the haplotype analysis, carriers of the ESR1 haplotype 2 (PvuII C and XbaI A) allele had a higher systolic and mean BP, and lower HRV spectral powers (total power, VLF, LF, and HF components) in a supine rest compared with those of non-carriers.

CONCLUSIONS

The ESR1 PvuII and XbaI haplotype is associated with BP variation and the reduction in cardiac autonomic nervous activity in young Japanese males, which may be precursors of future pathological episodes of cardiovascular diseases.

Association of estrogen receptor {alpha} genotypes/ haplotypes with carotid intima-media thickness in Taiwanese women

The estrogen receptor alpha gene (ESR1) is an important mediator of the atheroprotective effect of estrogen on the vasculature system. We examined the potential associations between common single nucleotide polymorphism (SNP) variants of ESR1 and intima-media thickness (IMT) in carotid arteries, a strong predictor of cardiovascular disease (CVD). A total of 760 study participants (343 men and 407 women), who had undergone a Duplex ultrasonographic examination of carotid artery, were investigated. Measurement of IMT was performed on a 10-mm segment of the common carotid artery (CCA). Fourteen sequence-validated SNPs of high frequency of Oriental origin were selected and genotyped by the method of Light-Cycler-480-assisted real-time polymerase chain reaction (PCR) followed by melting curve analysis. Results from multiple linear regression analyses showed significant associations of SNPs rs2228480 (Ex8+229G>A) and rs3798758 (Ex8+1988C>A) with the carotid IMT values in women but not in men. Women with SNP rs2228480 (Ex8+229G>A) A/A genotype had a 0.048 mm (7.1%) increase in IMT values versus the other genotypes combined (P = .030). In women who carried the rs3798758 (Ex8+1988C>A) CA+AA combined genotypes, their carotid IMT measures were 0.020 mm (2.9%) decreased as compared with those in women who carried C/ C genotype (P = .042). In haplotype analysis, women with the T-A haplotype versus C-C haplotype of combined rs3798577 (Ex8+1264T>C) and rs3798758 (Ex8+1988C>A) were also found to be associated with a decreased IMT value at a borderline significance (P = .057). Some common SNPs in the ESR1 could be important in modulating carotid atherosclerosis and thereby CVD susceptibility in Taiwanese women.

Role of genetic polymorphism of estrogen receptor-alpha gene and risk of prostate cancer in north Indian population

Present study depicted the role of polymorphisms in estrogen receptor-alpha gene in association with prostate cancer in north Indian population. The study was performed on 157 cases of prostate cancer, 170 cases of BPH, and 170 healthy Indian males diagnosed with prostate cancer and benign prostatic hyperplasia (BPH) and healthy males as controls. Determination of polymorphism in the ER-alpha gene was done by polymerase chain reaction followed by restriction fragment length polymorphism (RFLP) analysis with PvuII and XbaI enzymes. An association was observed between PvuII polymorphism of ER-alpha gene and that of prostate cancer. However, there was no such association with XbaI polymorphism in ER-alpha gene.

Sex/gender medicine. The biological basis for personalized care in cardiovascular medicine

Sex differences in morbidity and mortality associated with cardiovascular disease have been recognized by the medical community for decades. Investigation into the underlying biological basis of these differences was largely neglected by the scientific community until a report released by the Institute of Medicine in the United States in 2001 "Exploring the Biological Contributions to Human Health: Does Sex Matter?" Recommendations from this report included the need for more accurate use of the terms "sex" and "gender", better tools and resources to study the biological basis of sex differences, integration of findings from different levels of biological organization and continued synergy between basic and clinical researchers. Ten years after the Institute's report, this review evaluates some of the sex differences in cardiovascular disease, reviews new approaches to study sex differences and emphasizes areas where further research is required. In the era of personalized medicine, the study of the biological basis of sex differences promises to optimize preventive, diagnostic and therapeutic strategies for cardiovascular disease in men and women, but will require diligence by the scientific and medical communities to remember that sex does matter.

A functional polymorphism in estrogen receptor alpha gene is associated with Japanese methamphetamine induced psychosis

BACKGROUND

A recent study reported an association between rs2234693, which influences enhancer activity levels in estrogen receptor alpha gene (ESR1), and schizophrenia. This study reported that schizophrenic patients with the CC genotype have significantly lower ESR1 mRNA levels in the prefrontal cortex than patients with other genotypes. The symptoms of methamphetamine induced psychosis are similar to those of paranoid type schizophrenia. Therefore, we conducted an association analysis of rs2234693 with Japanese methamphetamine induced psychosis patients.

METHOD

Using rs2234693, we conducted a genetic association analysis of case-control samples (197 methamphetamine induced psychosis patients and 197 healthy controls). The age and sex of the control subjects did not differ from those of the methamphetamine induced psychosis patients.

RESULTS

We detected a significant association between ESR1 and methamphetamine induced psychosis patients in allele/genotype-wise analysis. For further interpretation of these associations, we performed single marker analysis of subjects divided by sex. Rs2234693 was associated with male methamphetamine induced psychosis.

DISCUSSION

Our results suggest that rs2234693 in ESR1 may play a role in the pathophysiology of Japanese methamphetamine induced psychosis patients.

Multilocus analyses reveal involvement of the ESR1, ESR2, and FSHR genes in migraine

OBJECTIVE

Female hormone genes have been investigated in migraine in recent years. Research in this field has been controversial, especially in regard to ESR1 gene findings. None of the reports have yet to approach the problem from a multigenic point of view.

METHODS

We investigated 5 polymorphisms implicated in female hormone metabolism (FSHR, CYP19A1, ESR1, NRIP1, and ESR2) in a cohort of 730 subjects matched for age and sex. The effect of gene-gene interaction was assessed using the set association approach, and the corresponding haplotypes were studied with PM Plus software. To corroborate initial results, we analyzed the selected markers using a cohort of 134 families in which 168 trios were suitable for transmission-disequilibrium test (TDT) analysis under the migraine with aura (MA) phenotype.

RESULTS

A total of 356 consecutive migraine patients (198 with MA [76% females] and 158 migraine without aura [MO, 74% females], and 374 matched controls [71% females]) were genotyped. In the 2-point analyses, the ESR1 and ESR2 polymorphisms showed nominal association under MA/MO phenotype, and this association was higher with the FSHR polymorphism in MA females (P = .004, uncorrected). Using the SUMSTAT program, we observed ESR2-ESR1-FSHR significant gene-gene interaction, suggesting association with the MA/MO phenotype (P = .005; P = .003 in females), and with MA alone (P = .021; P = .030 for females).We corroborated that ESR2-ESR1-FSHR haplotypes interacted for migraine under a model-free hypothesis (empirical P = .010 for the whole sample; P = .001 for females), and the association was stronger for the MA phenotype alone (empirical P = 5.0e-4, under the heterogeneity model; P = .001 for females). These results were corroborated using family-based association approaches. We observed nominal association for ESR2 and ESR1 (P = .031 and .034, respectively) in the TDT study, and significant association for ESR1 using family-based association test statistics. Haplotype-TDT analyses showed further significant gene-gene interaction for ESR1-ESR2 (global P = .009), ESR2-FSHR (global P = .011), and nominally significant interaction for ESR2-ESR1-FSHR genes (global P = .037).

CONCLUSION

We found significant association of female hormone metabolism polymorphisms under the perspective of multigene approach.

Estrogen receptor genotype is associated with risk of venous thromboembolism during tamoxifen therapy

Thromboembolism is a serious complication of tamoxifen therapy in women with breast cancer. Banked DNA from tamoxifen-treated individuals with breast cancer from the Marshfield Clinic Personalized Medicine Research Project, a population-based DNA repository, was tested for association between incidence of tamoxifen-associated thromboembolic events (TTE) and single nucleotide polymorphisms encoding the estrogen receptors 1,2 (ESR1, ESR2) or drug metabolism enzymes cytochrome P450 2D6 (CYP2D6) and aromatase (CYP19). TTE were experienced by 16/220 subjects with risk association noted for XbaI (rs9340799) genotype and ESR1 Xbal/PvuII diplotype (rs9340799 and rs2234693) (hazard ratio 3.47, 95% CI 0.97-12.44, P = 0.035). Association persisted after adjusting for classical risk factors including age at diagnosis and body mass index at enrollment. Initial evidence of association between increased risk for TTE and ESR1 genotype and ESR1 diplotype is presented. Determination of estrogen receptor genotype may identify a subset of women at increased risk for thromboembolism with tamoxifen exposure.