Estrogen receptor-mediated repression of human hepatic lipase gene transcription

The impact of female sex hormones on cardiovascular disease: from mechanisms to hormone therapy

Cardiovascular disease remains the leading cause of mortality in women, yet it has not raised the awareness from the public. The pathogenesis of cardiovascular disease differs significantly between females and males concerning the effect of sex hormones. Estrogen and progestogen impact cardiovascular system through genomic and non-genomic effects. Before menopause, cardiovascular protective effects of estrogens have been well described. Progestogens were often used in combination with estrogens in hormone therapy. Fluctuations in sex hormone levels, particularly estrogen deficiency, were considered the specific risk factor in women's cardiovascular disease. However, considerable heterogeneity in the impact of hormone therapy was observed in clinical trials. The heterogeneity is likely closely associated with factors such as the initial time, administration route, dosage, and formulation of hormone therapy. This review will delve into the pathogenesis and hormone therapy, summarizing the effect of female sex hormones on hypertension, pre-eclampsia, coronary heart disease, heart failure with preserved ejection fraction, and cardiovascular risk factors specific to women.

Contraception and Cardiovascular Effects: What Should the Cardiologist Know?

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is the leading cause of death in women. This review highlights contraceptive options and their effects on the cardiovascular system (CVS). It provides guidance to cardiologists to make informed decisions regarding the safety of contraceptive use and cardiovascular risk stratification in the care of women of childbearing age.

RECENT FINDINGS

Approximately 44% of American women live with some type of CVD. Many women use hormonal contraception during their lifetime. It is imperative that cardiologists have a robust understanding of the forms of contraception in current use and their cardiovascular effects. This contemporary review provides a comprehensive summary of available contraceptive methods to practicing cardiologists and aims to be used as a resource to guide cardiovascular specialists on contraception in the context of cardiovascular disease.

Efficacy and safety of anti-androgens in the management of polycystic ovary syndrome: a systematic review and meta-analysis of randomised controlled trials

Background

Anti-androgens and combined oral contraceptive pills (COCPs) may mitigate hyperandrogenism-related symptoms of polycystic ovary syndrome (PCOS). However, their efficacy and safety in PCOS remain unclear as previous reviews have focused on non-PCOS populations. To inform the 2023 International Evidence-based Guideline in PCOS, we conducted the first systematic review and meta-analysis investigating the efficacy and safety of anti-androgens in the management of hormonal and clinical features of PCOS.

Methods

We systematically searched MEDLINE, Embase, PsycInfo, All EBM reviews, and CINAHL up to 28th June 2023 for randomised controlled trials (RCTs) examining oral anti-androgen use, alone or in combination with metformin, COCPs, lifestyle, or other interventions, in women of any age, with PCOS diagnosed by Rotterdam, National Institutes of Health or Androgen Excess & PCOS Society criteria, and using a form of contraception. Non-English studies and studies of less than 6 months duration or which used the same anti-androgen regimen in both/all groups were excluded in order to establish efficacy for the clinical outcomes of interest. Three authors screened articles against selection criteria and assessed risk of bias and quality using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework. Critical outcomes (prioritised during guideline development for GRADE purposes) included weight, body mass index (BMI), irregular cycles, hirsutism, liver function, and quality of life. Random effects meta-analyses were conducted where appropriate. This study is registered with PROSPERO, CRD42022345640.

Findings

From 1660 studies identified in the search, 27 articles comprising 20 unique studies were included. Of these, 13 studies (n = 961) were pooled in meta-analysis. Seven studies had a high risk of bias, nine moderate and four low. Anti-androgens included finasteride, flutamide, spironolactone, or bicalutamide. In meta-analysis, anti-androgens + lifestyle were superior to metformin + lifestyle for hirsutism (weighted mean difference [WMD] [95% CI]: -1.59 [-3.06, -0.12], p = 0.03; I2 = 74%), SHBG (7.70 nmol/l [0.75, 14.66], p = 0.03; I2 = 0%), fasting insulin and fasting insulin: glucose ratio (-2.11 μU/ml [-3.97, -0.26], p = 0.03; I2 = 0% and -1.12 [-1.44, -0.79], p < 0.0001, I2 = 0%, respectively), but were not superior to placebo + lifestyle for hirsutism (-0.93, [-3.37, 1.51], p = 0.45; I2 = 76%) or SHBG (9.72 nmol/l [-0.71, 20.14], p = 0.07; I2 = 31%). Daily use was more effective for hirsutism than use every three days (-3.48 [-4.58, -2.39], p < 0.0001, I2 = 1%), and resulted in lower androstenedione levels (-0.30 ng/ml [-0.50, -0.10], p = 0.004; I2 = 0%). Combination treatment with anti-androgens + metformin + lifestyle resulted in lower testosterone compared with metformin + lifestyle (-0.29 nmol/l [-0.52, -0.06], p = 0.01; I2 = 61%), but there were no differences in hirsutism when anti-androgens + metformin + lifestyle were compared with either anti-androgens + lifestyle or metformin + lifestyle. In limited meta-analyses (n = 2 trials), combining anti-androgens with COCP resulted in poorer lipid profiles compared with COCP ± placebo, with no differences in other outcomes.

Interpretation

Current evidence does not support the use of anti-androgens preferentially to COCPs to treat hyperandrogenism in PCOS. Anti-androgens could be considered to treat hirsutism in PCOS, where COCPs are contraindicated, poorly tolerated, or present a sub-optimal response after a minimum 6-month period, with consideration of clinical context and individual risk factors and characteristics.

Funding

National Health and Medical Research Council (NHMRC) of Australia Monash University.

Associations of Oral Contraceptive Use With Cardiovascular Disease and All-Cause Death: Evidence From the UK Biobank Cohort Study

Background The associations of oral contraceptive (OC) use with cardiovascular disease (CVD) and all-cause death remains unclear. We aimed to determine the associations of OC use with incident CVD and all-cause death. Methods and Results This cohort study included 161 017 women who had no CVD at baseline and reported their OC use. We divided OC use into ever use and never use. Cox proportional hazard models were used to calculate hazard ratios and 95% CIs for cardiovascular outcomes and death. Overall, 131 131 (81.4%) of 161 017 participants reported OC use at baseline. The multivariable-adjusted hazard ratios for OC ever users versus never users were 0.92 (95% CI, 0.86-0.99) for all-cause death, 0.91 (95% CI, 0.87-0.96) for incident CVD events, 0.88 (95% CI, 0.81-0.95) for coronary heart disease, 0.87 (95% CI, 0.76-0.99) for heart failure, and 0.92 (95% CI, 0.84-0.99) for atrial fibrillation. However, no significant associations of OC use with CVD death, myocardial infarction, or stroke were observed. Furthermore, the associations of OC use with CVD events were stronger among participants with longer durations of use (P for trend<0.001). Conclusions OC use was not associated with an increased risk of CVD events and all-cause death in women and may even produce an apparent net benefit. In addition, the beneficial effects appeared to be more apparent in participants with longer durations of use.

Per- and Polyfluoroalkyl Substances (PFAS) and Lipid Trajectories in Women 45-56 Years of Age: The Study of Women's Health Across the Nation

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are associated with less favorable blood lipid profiles in epidemiological studies. However, little is known about the potential role of PFAS in longitudinal changes in lipids among midlife women even though women become more susceptible to metabolic alterations during the menopausal transition.

OBJECTIVES

To examine associations of serum PFAS concentrations with longitudinal trajectories of blood total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides in midlife women undergoing menopausal transition.

METHODS

The sample included 1,130 women from the Study of Women's Health Across the Nation 45-56 y of age at baseline (1999-2000). We measured serum PFAS concentrations including linear perfluorooctanoic acid (n-PFOA), perfluorononanoic acid (PFNA), linear and branched perfluorooctanesulfonic acid (n-PFOS and Sm-PFOS, respectively), and perfluorohexanesulfonic acid (PFHxS) at baseline. We used k-means clustering to identify subgroups with different patterns of PFAS mixture. Blood lipids were measured annually or biannually through 2016 with an average follow-up of 14.8 y. We identified longitudinal trajectories of each lipid using latent class growth models. We used multinomial log-linear models adjusted for covariates to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of lipid trajectory classes by PFAS and their mixtures.

RESULTS

Three distinct trajectories (low, middle, high) of total, LDL, and HDL cholesterol and two distinct trajectories (low and high) of triglycerides were identified. n-PFOS, Sm-PFOS, and PFHxS were positively associated with total and LDL cholesterol trajectories. n-PFOS was inversely associated with triglycerides trajectories. PFAS mixtures (high vs. low) showed positive associations with total and LDL cholesterol trajectories (high vs. low), showing ORs (95% CIs) of 1.69 (95% CI: 1.36, 2.12) and 1.79 (95% CI: 1.44, 2.22), respectively.

DISCUSSION

Concentrations of serum PFAS were positively associated with trajectories of total and LDL cholesterol, providing a line of evidence supporting adverse effects of PFAS on lipid homeostasis. https://doi.org/10.1289/EHP12351.

Dyslipidemia in the first 100 days and the association with acute graft-versus-host disease after allogeneic stem cell transplantation: A single-center retrospective study in China

Dyslipidemia is a common complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The interaction between post-transplant hyperlipidemia and acute graft-versus-host disease (aGVHD) is uncertain. In this study, we performed a retrospective study to explore the relationship between dyslipidemia and aGVHD and the potential mechanism of aGVHD on dyslipidemia in 147 recipients who underwent allo-HSCT. The lipid profiles, transplantation details, and other laboratory data of the subjects were collected in the first 100 days post-transplantation. Our results indicated 63 patients with new-onset hypertriglyceridemia and 39 patients with new-onset hypercholesterolemia. A total of 57 (38.8%) patients developed aGVHD after transplantation. In a multifactorial analysis, aGVHD was an independent factor in the development of dyslipidemia in recipients (P < 0.05). After transplantation, the median LDL-C level of patients with aGVHD was 3.04 mmol/L (standard deviation value (SD): 1.36 mmol/L, 95% confidence interval (CI): 2.62, 3.45 mmol/L), and the LDL-C level in patients without aGVHD was 2.51 mmol/L (SD: 1.38 mmol/L, CI: 2.67, 3.40 mmol/L) (P < 0.05). Female recipients had higher lipid levels than males (P < 0.05). LDL levels (≥ 3.4 mmol/L) post-transplant were an independent risk factor for the development of aGVHD (OR = 0.311, P < 0.05). In conclusion, larger sample studies are anticipated to confirm our preliminary result, and an accurate mechanism between lipid metabolism and aGVHD needs to be determined in the future.

Acute pancreatitis secondary to tamoxifen-associated hypertriglyceridemia: A clinical update

INTRODUCTION

Drug-induced pancreatitis has been increasingly recognized, but it is frequently encountered as an inconspicuous etiology. The underlying mechanisms of injury vary with different drugs. Tamoxifen is a frequently used anticancer drug that acts by selective modulation of the estrogen receptor in patients with breast cancer. Tamoxifen-induced hypertriglyceridemia is a relatively rare etiological factor for acute pancreatitis. However, acute pancreatitis secondary to this adverse effect remains an exceedingly important clinicopathologic entity.

CASE REPORT

We hereby delineate a rare case of acute pancreatitis secondary to hypertriglyceridemia in a patient who was on tamoxifen treatment for the past 3 years. Her serum lipase and triglyceride levels were markedly elevated at 14,285 IU/L and 20,344 mg/dL, respectively. The diagnosis was considered based on the findings of a standard diagnostic workup and exclusion of alternative causes of acute pancreatitis.

MANAGEMENT AND OUTCOME

The patient was instituted prompt treatment with intravenous insulin infusion and gemfibrozil. The clinical outcome was favorable with no complications. Tamoxifen was permanently discontinued and was replaced with letrozole.

DISCUSSION

This article illustrates that acute pancreatitis should be considered in the differential diagnoses of abdominal pain and elevated pancreatic enzymes in patients undergoing tamoxifen treatment. It also underscores the importance of pre- and post-tamoxifen lipid screening, especially in patients with a history of dyslipidemia and diabetes mellitus. It will facilitate an expedient detection of hypertriglyceridemia, potentially saving patients from associated morbidity and mortality.

Dyslipidemia in midlife women: Approach and considerations during the menopausal transition

Dyslipidemia is an established risk factor for cardiovascular disease (CVD), which remains the leading cause of morbidity and mortality in women globally. The incidence of dyslipidemia increases over a woman's lifespan, with adverse changes around the time of menopause. Menopause, and the years leading up to the final menstrual period, is a time of estrogen fluctuation and ultimately estrogen deficiency, which has been associated with proatherogenic changes in the lipid profile. Independent of aging, menopausal status is associated with elevations in serum total cholesterol, LDL cholesterol, apolipoproteins, and triglycerides, and decreases in HDL cholesterol (HDL-C). Emerging research also suggests that after menopause there is a loss of functional HDL cardioprotective properties. Early initiation of menopausal hormone therapy (MHT) confers a favorable effect on lipid profile, though this does not translate into improved CVD outcomes and therefore guidelines do not indicate it for primary or secondary prevention of CVD. At the time of menopause, special consideration should be given to women with conditions more associated with CVD, including polycystic ovarian syndrome, premature menopause, early menopause, premature ovarian insufficiency, and familial hypercholesterolemia. Statins remain the mainstay of dyslipidemia therapy, though novel lipid-lowering agents are emerging. This review provides an overview of lipid alterations observed during the menopausal transition, summarizes the current evidence on the role of estrogen and progestogen on lipids, identifies special populations of women at especially high risk for lipid dysregulation at menopause, and describes approaches to the screening and treatment of midlife women.

Crosstalk between high-density lipoproteins and endothelial cells in health and disease: Insights into sex-dependent modulation

Atherosclerotic cardiovascular disease is the leading cause of death worldwide. Intense research in vascular biology has advanced our knowledge of molecular mechanisms of its onset and progression until complications; however, several aspects of the patho-physiology of atherosclerosis remain to be further elucidated. Endothelial cell homeostasis is fundamental to prevent atherosclerosis as the appearance of endothelial cell dysfunction is considered the first pro-atherosclerotic vascular modification. Physiologically, high density lipoproteins (HDLs) exert protective actions for vessels and in particular for ECs. Indeed, HDLs promote endothelial-dependent vasorelaxation, contribute to the regulation of vascular lipid metabolism, and have immune-modulatory, anti-inflammatory and anti-oxidative properties. Sex- and gender-dependent differences are increasingly recognized as important, although not fully elucidated, factors in cardiovascular health and disease patho-physiology. In this review, we highlight the importance of sex hormones and sex-specific gene expression in the regulation of HDL and EC cross-talk and their contribution to cardiovascular disease.

Effects of hormone replacement therapy on glucose and lipid metabolism in peri- and postmenopausal women with a history of menstrual disorders

BACKGROUND

Previous studies have indicated that women with a history of menstrual disorders have an increased risk of metabolic and cardiovascular diseases. This has been attributed to the high proportion of polycystic ovary syndrome (PCOS) among this group. The favorable effects of hormone replacement therapy (HRT) on serum lipid profiles and glucose homeostasis in postmenopausal women is widely accepted. Whether HRT can also show positive effects on metabolic homeostasis in menopausal women with prior menstrual disorders (a putative PCOS phenotype) has not been reported yet. The aim of the study was to compare the effects of HRT on glucose and lipid metabolism in peri- and postmenopausal women with prior menstrual disorders and controls who did not have prior menstrual disorders.

METHODS

A retrospective multicenter study was conducted including 595 peri- and postmenopausal women who received HRT at four hospitals in the Zhejiang Province from May 31, 2010 to March 8, 2021. Participants were divided into the Normal menstruation group and the Menstrual disorders group according to their prior usual menstrual cycle pattern. Glucose and lipid metabolism indicators were assessed at baseline and after HRT. The results were compared between and within the groups, and data from peri- and postmenopausal women were analyzed separately.

RESULTS

HRT significantly decreased fasting insulin and homeostasis model assessment of insulin resistance in perimenopausal users, and fasting plasma glucose levels in postmenopausal users with prior menstrual disorders, compared with baseline. Furthermore, HRT decreased low-density lipoprotein cholesterol, total cholesterol, fasting insulin, fasting plasma glucose and homeostasis model assessment of insulin resistance in both peri- and postmenopausal controls, compared with baseline. Nevertheless, no significant differences were observed in any of the glucose or lipid metabolism indicators at baseline and follow-up, as well as changes from baseline levels between menopausal women with and without prior menstrual disorders.

CONCLUSIONS

HRT shows more obvious within-group improvements in glucose and lipid metabolism in controls, but there is no significant between-group difference. Further prospective studies are required for confirmation.

A case of tamoxifen-induced hypertriglyceridemia monitoring the changes in lipoprotein fractions over time

BACKGROUND

Tamoxifen, which is one of the selective estrogen receptor modulators (SERMs), can bring out life-threatening complication, e.g. hypertriglyceridemia-induced acute pancreatitis, although it is rare. We precisely report changes in lipoprotein metabolism before and after tamoxifen discontinuation because there have been few reports of it.

CASE PRESENTATION

47-year-old premenopausal woman with dyslipidemia, type 2 diabetes, nonalcoholic fatty liver disease and chronic kidney disease was prescribed tamoxifen as adjuvant therapy after operation of breast cancer. She experienced severe tamoxifen-induced hypertriglyceridemia several months after dosing tamoxifen. Before cessation of tamoxifen, lipoprotein fraction test revealed marked stagnation of VLDL and IDL metabolisms, resulting in severe hypertriglyceridemia (serum triglyceride level was 1881 mg/dL). Seven days after tamoxifen withdrawal, lipoprotein fraction test showed that the metabolisms of endogenous lipoproteins were changed drastically.

CONCLUSIONS

From these results, we confirmed that tamoxifen certainly changes lipoprotein metabolism through suppression of post-heparin lipolytic activity. It is very important to evaluate the balance between benefit and risk before dosing tamoxifen and survey lipid profiles constantly during treatment to avoid life-threatening complication when prescription of tamoxifen is planned.

Analysis of Intrinsic and Extrinsic Coagulation Pathway Factors in OCP Treated PCOS Women

Human polycystic ovary syndrome (PCOS)-a cluster of diseases displays various symptoms associated with endocrine and gynecological disorders in childbearing women. Oral contraceptive pills (OCP) being a drug of choice minimizes symptoms and complications associated with the disorder. But, the controversial data available in literature regarding use of OCPs compels us to setup a study design regarding effect of OCP treatment in PCOS subjects and the possible outcomes specifically regarding coagulation pathways. Two PCOS study groups have been selected according to Rotterdam Criteria: one with OCP treatment (n = 50) and other without any drug treatment i.e., drug naive (n = 50). Anthropometry, Biochemistry, Hormones, Insulin and various clotting factors like Factor XI, Factor V, tPA, TAT-III and D-dimer were analyzed in both groups. The results showed worsening of IR, Metabolic parameters and coagulopathy in OCP group comparative to drug naive group indicating adverse effects of the OCP treatment which puts these women at risk for number of future clinical implications especially Cardiovascular and metabolic complications.

Sex-Specific Determinants of Coronary Artery Disease and Atherosclerotic Risk Factors: Estrogen and Beyond

The way we view coronary artery disease in women has changed dramatically over the past decades. From an initial perspective that coronary artery disease was a male disorder and that women were protected by estrogens, there has been the gradual appreciation that this is an equal opportunity disease. Postmenopausal women are more likely than men to be hypertensive, dyslipidemic, and have multiple risk factors. Beyond the appreciation of estrogen's global effects on cardiovascular and metabolic function, our further advances in the understanding of sex-specific risks and management will be based on a greater understanding of the diversity of estrogen-mediated receptor pathways, including appreciation of the sometimes divergent effects of estrogen when acting either via the classic estrogen receptor or the more recently appreciated G protein-coupled estrogen receptor. In addition, the importance of sex-specific regulation of cardiometabolic processes beyond the sex hormones, specifically via SRY regulation, is only beginning to be understood. Finally, the author summarizes his recent studies demonstrating sex-specific G protein-coupled estrogen receptor regulation of blood pressure and cholesterol metabolism that may serve as a paradigm for the elucidation of sex-specific determinants of cardiovascular risk and the basis for sex-specific management of those risks.

Application of metabolomics to preeclampsia diagnosis

Preeclampsia is a multifactorial disorder defined by hypertension and increased urinary protein excretion during pregnancy. It is a significant cause of maternal and neonatal deaths worldwide. Despite various research efforts to clarify pathogenies of preeclampsia and predict this disease before beginning of symptoms, the pathogenesis of preeclampsia is unclear. Early prediction and diagnosis of women at risk of preeclampsia has not markedly improved. Therefore, the objective of this study was to perform a review on metabolomic articles assessing predictive and diagnostic biomarkers of preeclampsia. Four electronic databases including PubMed/Medline, Web of Science, Sciencedirect, and Scopus were searched to identify studies of preeclampsia in humans using metabolomics from inception to March 2018. Twenty-one articles in a variety of biological specimens and analytical platforms were included in the present review. Metabolite profiles may assist in the diagnosis of preeclampsia and discrimination of its subtypes. Lipids and their related metabolites were the most generally detected metabolites. Although metabolomic biomarkers of preeclampsia are not routinely used, this review suggests that metabolomics has the potential to be developed into a clinical tool for preeclampsia diagnosis and could contribute to an improved understanding of disease mechanisms.

ABBREVIATIONS

PE: preeclampsia; sFlt-1: soluble FMS-like tyrosine kinase-1; PlGF: placental growth factor; GC-MS: gas chromatography-mass spectrometry; LC-MS: liquid chromatography-mass spectrometry; NMR: nuclear magnetic resonance spectroscopy; HMDB: human metabolome database; RCT: randomized control trial; e-PE: early-onset PE; l-PE: late-onset PE; PLS-DA: partial least-squares-discriminant analysis; CRL: crown-rump length; UtPI: uterine artery Doppler pulsatility index; BMI: body mass index; MAP: mean arterial pressure; OS: oxidative stress; PAPPA: plasma protein A; FTIR: Fourier transform infrared; BCAA: branched chain amino acids; Arg: arginine; NO: nitric oxide.

Combined Oral Contraceptives Increase High-Sensitivity C-Reactive Protein but Not Haptoglobin in Female Athletes

BACKGROUND

No studies have examined the effects of oral hormonal contraception on chronic low-grade inflammation as assessed by stratified levels of high-sensitivity C-reactive protein (hsCRP) in athletes. We explored the impact of combined oral contraceptives (OCs) on serum hsCRP, haptoglobin, triglycerides and cholesterol in white female athletes.

METHODS

Italian sportswomen (n = 205; mean age 24 ± 5.3 years; body mass index 21 ± 2.2 kg m^-2; sport activity 8.7 ± 3.65 h week^-1) were analyzed according to OC use.

RESULTS

Progressive hsCRP levels were evaluated in OC users (n = 53) compared to non-OC users (n = 152). Levels of hsCRP from 3.0 to <10.0 mg L^-1 (at high risk of future cardiovascular events) were found in 26.4 % (14/53) of OC users and only in 2.6 % (4/153) of non-OC users (OR = 13.3, 95 % CI 4.14-42.6, P < 0.001). Risky hsCRP levels ≥1.0 mg L^-1 were found in 62.3 % of OC users versus 13.2 % non-OC users (OR = 10.9, 95 % CI 5.26-22.5, P < 0.001). Protective hsCRP levels (<0.5 mg L^-1) were found in 17.0 % of OC users and in 64.5 % of non-OC users (OR = 0.11, 95 % CI 0.05-0.25, P < 0.001). OC use increased serum triglycerides (P < 0.001), total cholesterol (P = 0.027) and HDL cholesterol (P = 0.018), whereas haptoglobin was unaffected. Hours of exercise week^-1 had a mild inverse association with hsCRP (P = 0.048) in non-OC users only.

CONCLUSIONS

OC use markedly elevated chronic low-grade inflammation in athletes, which could predispose to a higher inflammatory response to physical stress and elevate cardiovascular risk. Physical activity without OC use seemed to favor low hsCRP. Further research is needed to extend our results and to elucidate the potential effects on athletic performance of chronically elevated hsCRP. Our findings would be useful for sport physicians interpreting blood tests in athletes.

HDL and the menopause

PURPOSE OF REVIEW

To summarize recent provocative findings on conventional and novel metrics of HDL including HDL-C, HDL subclasses and HDL cholesterol efflux capacity as related to menopause.

RECENT FINDINGS

Pattern of menopause-related changes in HDL-C are not consistent, suggesting a complex relationship between HDL and menopause. Growing body of literature indicates that higher levels of HDL-C may not be consistently cardio-protective in midlife women, suggesting a potential change in other metrics of HDL that could not be captured by the static metric HDL-C. It is also possible that higher HDL-C at certain conditions could be a marker of HDL metabolism dysfunctionality. Significant alterations in other metrics of HDL have been reported after menopause and found to be related to estradiol.

SUMMARY

The impact of changes in novel metrics of HDL over the menopausal transition on cardiovascular disease (CVD) risk later in life is not clear in women. Much of our understanding of how the menopausal transition may impact HDL metrics comes from cross-sectional studies. Future longitudinal studies are needed to evaluate other metrics of HDL shown to better reflect the cardio-protective capacities of HDL, so that the complex association of menopause, HDL and CVD risk could be characterized.

17β-estradiol regulates the expression of apolipoprotein M through estrogen receptor α-specific binding motif in its promoter

Background

We have previously demonstrated that estrogen could significantly enhance expression of apolipoprotein M (apoM), whereas the molecular basis of its mechanism is not fully elucidated yet. To further investigate the mechanism behind the estrogen induced up-regulation of apoM expression.

Results

Our results demonstrated either free 17β-estradiol (E2) or membrane-impermeable bovine serum albumin-conjugated E2 (E2-BSA) could modulate human apoM gene expression via the estrogen receptor alpha (ER-α) pathway in the HepG2 cells. Moreover, experiments with the luciferase activity analysis of truncated apoM promoters could demonstrate that a regulatory region (from-1580 to −1575 bp (−GGTCA-)) upstream of the transcriptional start site of apoM gene was essential for the basal transcriptional activity that regulated by the ER-α. With the applications of an electrophoresis mobility shift assay and a chromatin immunoprecipitation assay, we could successfully identify a specific ER-α binding element in the apoM promoter region.

Conculsion

In summary, the present study indicates that 17β-estradiol induced up-regulation of apoM in HepG2 cells is through an ER-α-dependent pathway involving ER-α binding element in the promoter of the apoM gene.

Alterations in Lipid Profile, Zinc and Copper Levels and Superoxide Dismutase Activities in Normal Pregnancy and Preeclampsia

BACKGROUND

Increased oxidative stress (OS) and lipid peroxidation may be involved in the pathogenesis of preeclampsia (PE). We conducted a case-control study to evaluate the levels of plasma lipids and trace elements as well as activity of superoxide dismutase (SOD) in PE.

MATERIALS AND METHODS

The study consisted of 100 patients who had been diagnosed with PE and 100 normotensive pregnant women who underwent medical checkups that served as the control group. Lipid profile, zinc (Zn) and copper (Cu) levels and SOD activities were measured in the plasma of all subjects.

RESULTS

Our results showed that the plasma levels of triglycerides and SOD activity were significantly elevated and the levels of Zn and Cu were significantly reduced in patients with PE compared with healthy controls. Increased levels of SOD may indicate antioxidant protective mechanisms against OS in PE-complicated pregnancies. This finding may suggest an involvement of OS in the pathophysiology of PE.

CONCLUSION

This study demonstrated a significant negative correlation between SOD activity and levels of trace elements. Furthermore, we suggest that higher triglyceride levels and SOD activity combined with lower Zn and Cu levels may be associated with an increased risk of PE.

Association of PvuII and XbaI polymorphisms on estrogen receptor alpha (ESR1) gene to changes into serum lipid profile of post-menopausal women: Effects of aging, body mass index and breast cancer incidence

Estrogen is a steroidal hormone involved in several physiological functions in the female body including regulation of serum lipid metabolism and breast cancer (BC). Estrogen actions on serum lipids mostly occur through its binding to intracellular Estrogen Receptor alpha (ERalpha) isoform, expressed in most of tissues. This gene (ESR1) exhibit many polymorphic sites (SNPs) located either on translated and non-translated regions that regulate ERalpha protein expression and function. This paper aimed to investigate the association of two intronic SNPs of ESR1 gene, namely c454-397T>C (PvuII) and c454-351A>G (XbaI) to alterations in serum levels of total cholesterol (T-chol), total lipid (TL), low density lipoprotein cholesterol (LDL), high density lipoprotein (HDL), and triglycerides (TG) in a cohort of post-menopausal women. In addition, we aimed to associate presence of these SNPs to development of BC along 5 years period. To do so, a group of healthy 499, highly miscigenated, post-menopausal Brazilian women, were carried using PCR-FRLP technique and further confirmed by automatic sequence analysis as well followed through 5 years for BC incidence. Measurements of serum lipid profile by standard commercial methods were carried individually whereas Dual Energy X-ray Absorciometry (DXA) measured Body Mass Indexes (BMI), Fat Mass (FM), Lean Body Mass (LBM), and Body Water Content (BWC). No effects of PvuII SNP on ESR1 gene were observed on patient´s serum T-chol, TL, LDL, HDL, and TG. However, c454-397T>C PvuII SNP is associated to lower body fat and higher levels of lean mass and body water and lower incidence of BC. On the other hand, statistically significant effect of XbaI c454-351A>G SNP on serum TG and TL levels. Patients homozygous for X allele were followed up from 2010–2015. They showed higher incidence of breast cancer (BC) when compared to either heterozygous and any P allele combination. Moreover, the increasing of TG and TL serum concentrations associated to SNP XbaI c454-351A>G on ESR1 gene is enhanced in both obese (higher BMI) and elder women. Taken together, these results suggested that XbaI c454-351A>G SNP is associated to changes in lipid profile, particularly in serum TG and TL, in this cohort of post-menopausal woman. Also, this paper shows another link between obesity and BC corroborating the current thesis that both diseases are interlinked.

Regulation of Expression of Hyperalgesic Priming by Estrogen Receptor α in the Rat

Hyperalgesic priming, a sexually dimorphic model of transition to chronic pain, is expressed as prolongation of prostaglandin E2-induced hyperalgesia by the activation of an additional pathway including an autocrine mechanism at the plasma membrane. The autocrine mechanism involves the transport of cyclic adenosine monophosphate (AMP) to the extracellular space, and its conversion to AMP and adenosine, by ecto-5'phosphodiesterase and ecto-5'nucleotidase, respectively. The end product, adenosine, activates A1 receptors, producing delayed onset prolongation of prostaglandin E2 hyperalgesia. We tested the hypothesis that the previously reported, estrogen-dependent, sexual dimorphism observed in the induction of priming is present in the mechanisms involved in its expression, as a regulatory effect on ecto-5'nucleotidase by estrogen receptor α (EsRα), in female rats. In the primed paw AMP hyperalgesia was dependent on conversion to adenosine, being prevented by ecto-5'nucleotidase inhibitor α,β-methyleneadenosine 5'-diphosphate sodium salt and A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine. To investigate an interaction between EsRα and ecto-5'nucleotidase, we treated primed female rats with oligodeoxynucleotide antisense or mismatch against EsRα messenger RNA. Whereas in rats treated with antisense AMP-induced hyperalgesia was abolished, the A1 receptor agonist N⁶-cyclopentiladenosine still produced hyperalgesia. Thus, EsRα interacts with this autocrine pathway at the level of ecto-5'nucleotidase. These results demonstrate a sexually dimorphic mechanism for the expression of priming.

PERSPECTIVE

This study presents evidence of an estrogen-dependent mechanism of expression of chronic pain in female rats, supporting the suggestion that differential targets must be considered when establishing protocols for the treatment of painful conditions in men and women.

Regional and sex-related differences in modulating effects of female sex steroids on ecto-5'-nucleotidase expression in the rat cerebral cortex and hippocampus

Ecto-5'-nucleotidase (eN), a membrane rate-limiting enzyme of the purine catabolic pathway, catalyzes the conversion of AMP to adenosine involved in the regulation of many brain physiological and pathological processes. Since gender fundamentally determines hormonal milieu in the body and brain, it is reasonable to assume that sex differences in the activity of various signaling systems, including adenosine, may be generated by gonadal steroids. Thus, we examined expression of eN as a component of adenosine signaling system in the basal state in cerebral cortex and hippocampus of male and female rats at gene, protein and functional level, as well as in the state of gonadal hormone deprivation, induced by ovariectomy (OVX), whereas impact of steroid hormones was explored after repeated administration of 17α-estradiol, 17β-estradiol and progesterone for seven consecutive days. Results showed regional and sex-related differences in basal eN activity level, with the highest AMP hydrolysis observed in the hippocampus of male rats. Furthermore, ovarian steroids do not contribute to basal gene eN expression or the activity in cortical and hippocampal region of female rats. However, protein eN expression was increased in OVX rats in both investigated region. Investigated exogenous steroids had no influence on eN expression in male brain, while in OVX females alterations in eN activity were induced. The observed effects in female rats were different between examined regions e.g. in cortex, applied treatments predominantly decreased whereas in hippocampus increased eN activity. Based on the presented results, eN exerts regional and sex-related response in basal state as well as after treatment with female gonadal hormones, however the exact mechanisms of sex steroids actions on eN remain unclear and should be fully explored.

An Essential Role for Liver ERα in Coupling Hepatic Metabolism to the Reproductive Cycle

Lipoprotein synthesis is controlled by estrogens, but the exact mechanisms underpinning this regulation and the role of the hepatic estrogen receptor α (ERα) in cholesterol physiology are unclear. Utilizing a mouse model involving selective ablation of ERα in the liver, we demonstrate that hepatic ERα couples lipid metabolism to the reproductive cycle. We show that this receptor regulates the synthesis of cholesterol transport proteins, enzymes for lipoprotein remodeling, and receptors for cholesterol uptake. Additionally, ERα is indispensable during proestrus for the generation of high-density lipoproteins efficient in eliciting cholesterol efflux from macrophages. We propose that a specific interaction with liver X receptor α (LXRα) mediates the broad effects of ERα on the hepatic lipid metabolism.

17β-Estradiol upregulates ecto-5'-nucleotidase (CD73) in hippocampal synaptosomes of female rats through action mediated by estrogen receptor-α and -β

17β-Estradiol (E2) crucially affects several processes in the hippocampus of both sexes. E2 acts upon estradiol receptors ERα and ERβ, influencing target gene expression and/or modulates intracellular signaling cascades. Another potent modulator of hippocampal function is nucleoside adenosine, the final product of ectonucleotidase cascade, enzymes which hydrolyze extracellular ATP to adenosine. The last and rate-limiting step of the hydrolysis is catalyzed by membrane-bound ecto-5'-nucleotidase (eN). Previous findings obtained on adenosine metabolism in brain suggest that eN may be modulated by ovarian steroids. Therefore, the present study reports that the activity and protein abundance of membrane-bound eN fluctuates across the estrus cycle in the hippocampal synaptosomes of female rats. Further, we analyzed the role of E2 and its intracellular receptors on the expression of eN in ovariectomized females. We found that E2 upregulated eN activity and protein abundance in the hippocampal synaptosomes. Application of nonspecific ER antagonist, ICI 182,780 and selective ERα and ERβ agonists, PPT and DPN, respectively, demonstrated the involvement of both receptor subtypes in observed actions. Selective ERα receptor agonist, PPT, induced upregulation of both the protein level and activity of eN, while application of selective ERβ receptor agonist, DPN, increased only the activity of eN. In both cases, E2 entered into the intracellular compartment and activated ER(s), which was demonstrated by membrane impermeable E2-BSA conjugate. Together these results imply that E2-induced effects on connectivity and functional properties of the hippocampal synapses may be in part mediated through observed effect on eN.

The impact of oral contraceptives on cardiometabolic parameters

PURPOSE

There is much controversy regarding the use of oral contraceptive pills (OCPs) on cardiometabolic parameters, which is why this longitudinal population-based study was conducted to assess the impact of OCP use and its duration on cardiometabolic factors.

METHODS

Of 5532 reproductive-aged participants of the Tehran lipid and glucose study, 3160 women who met our inclusion criteria were subdivided according to the duration of OCPs consumption into four sub-groups: (1) Non-users; (2) <11 month users; (3) 12-35 month users, and (4) ≥36 month users, and their cardiometabolic parameters were compared.

RESULTS

No statistical significant differences were observed between the cardiometabolic parameters of these sub-groups, after further adjustment for confounding factors including age, parity, and education, except for mean low-density lipoprotein-cholesterol which was significantly higher in women who used OCPs for >36 months in comparison to non-OCP users. The odds ratio of hypercholesterolemia was significantly higher in women who used OCPs for >36 months in comparison to non-OCP users; being 1.5 times higher than non-users (95 % CI 1.01-2.2).

CONCLUSION

Results showed that if used for less than 3 years, OCPs have no cardiometabolic effects.

Gender specific effect of LIPC C-514T polymorphism on obesity and relationship with plasma lipid levels in Chinese children

Hepatic lipase (LIPC) is a key rate-limiting enzyme in lipoprotein catabolism pathways involved in the development of obesity. The C-514T polymorphism in the promoter region is associated with decreased LIPC activity. We performed a case-controlled study (850 obese children and 2119 controls) and evaluated the association between LIPC C-514T polymorphism, obesity and plasma lipid profile in Chinese children and adolescents. Additionally, we conducted a meta-analysis of all results from published studies as well as our own data. A significant association between the polymorphism and obesity is observed in boys (P = 0.042), but not in girls. And we observed a significant relationship of the polymorphism with total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) independent of obesity in boys. The T allele carriers have higher levels of low density lipoprotein cholesterol (LDL-C) in obese boys, and triglyceride (TG), TC and LDL-C in non-obese girls (all P < 0.05). In the meta-analysis, under dominant model the T allele increased body mass index (BMI) level in boys, while it decreased BMI in girls, and increased the levels of TC both in the overall and subgroups, TG and HDL-C in the overall and boys, and LDL-C in the overall (all P < 0.05). Our results suggest that the T allele might carry an increased risk of obesity in Chinese boys. The meta-analysis suggests that T allele acts as a risk allele for higher BMI levels in male childhood, while it is a protective allele in female childhood. And the polymorphism is associated with the levels of plasma lipids, which may be modulated by obesity and gender.

LncRNA HOTAIR: A master regulator of chromatin dynamics and cancer

Non-coding RNAs (ncRNAs) are emerging classes of regulatory RNA that play key roles in various cellular and physiological processes such as in gene regulation, chromatin dynamics, cell differentiation, and development. NcRNAs are dysregulated in a variety of human disorders including cancers, neurological disorders, and immunological disorders. The mechanisms through which ncRNAs regulate various biological processes and human diseases still remain elusive. HOX antisense intergenic RNA (HOTAIR) is a recently discovered long non-coding RNA (lncRNA) that plays critical role in gene regulation and chromatin dynamics, appears to be misregulated in a variety of cancers. HOTAIR interacts with key epigenetic regulators such as histone methyltransferase PRC2 and histone demethylase LSD1 and regulates gene silencing. Here, we have reviewed recent advancements in understanding the functions and regulation of HOTAIR and its association with cancer and other diseases.

G-protein estrogen receptor as a regulator of low-density lipoprotein cholesterol metabolism: cellular and population genetic studies

OBJECTIVE

Estrogen deficiency is linked with increased low-density lipoprotein (LDL) cholesterol. The hormone receptor mediating this effect is unknown. G-protein estrogen receptor (GPER) is a recently recognized G-protein-coupled receptor that is activated by estrogens. We recently identified a common hypofunctional missense variant of GPER, namely P16L. However, the role of GPER in LDL metabolism is unknown. Therefore, we examined the association of the P16L genotype with plasma LDL cholesterol level. Furthermore, we studied the role of GPER in regulating expression of the LDL receptor and proprotein convertase subtilisin kexin type 9.

APPROACH AND RESULTS

Our discovery cohort was a genetically isolated population of Northern European descent, and our validation cohort consisted of normal, healthy women aged 18 to 56 years from London, Ontario. In addition, we examined the effect of GPER on the regulation of proprotein convertase subtilisin kexin type 9 and LDL receptor expression by the treatment with the GPER agonist, G1. In the discovery cohort, GPER P16L genotype was associated with a significant increase in LDL cholesterol (mean±SEM): 3.18±0.05, 3.25±0.08, and 4.25±0.33 mmol/L, respectively, in subjects with CC (homozygous for P16), CT (heterozygotes), and TT (homozygous for L16) genotypes (P<0.05). In the validation cohort (n=339), the GPER P16L genotype was associated with a similar increase in LDL cholesterol: 2.17±0.05, 2.34±0.06, and 2.42±0.16 mmol/L, respectively, in subjects with CC, CT, and TT genotypes (P<0.05). In the human hepatic carcinoma cell line, the GPER agonist, G1, mediated a concentration-dependent increase in LDL receptor expression, blocked by either pretreatment with the GPER antagonist G15 or by shRNA-mediated GPER downregulation. G1 also mediated a GPER- and concentration-dependent decrease in proprotein convertase subtilisin kexin type 9 expression.

CONCLUSIONS

GPER activation upregulates LDL receptor expression, probably at least, in part, via proprotein convertase subtilisin kexin type 9 downregulation. Furthermore, humans carrying the hypofunctional P16L genetic variant of GPER have increased plasma LDL cholesterol. In aggregate, these data suggest an important role of GPER in the regulation of LDL receptor expression and consequently LDL metabolism.

Hyperinsulinaemic androgen excess in adolescent girls

Hyperinsulinaemic androgen excess is the most common cause of hirsutism, acne and menstrual irregularity in adolescent girls. Here, we propose that the disorder frequently originates from an absolute or relative excess of lipids in adipose tissue, and from associated changes in insulin sensitivity, gonadotropin secretion and ovarian androgen release. Girls from populations with genotypes attuned to nutritionally harsh conditions seem to be particularly vulnerable to the development of hyperinsulinaemic androgen excess in today's obesogenic environment. We propose that hirsutism, hyperandrogenaemia and menstrual irregularity (≥2 years after menarche) is used as a diagnostic triad for the disorder. No pharmacological therapy has been approved for girls with androgen excess; however, lifestyle intervention is essential to reduce adiposity. In girls without obesity who are not sexually active, insulin sensitization has more broadly normalizing effects than estradiol-progestogen combinations. The early recognition of girls at risk of developing hyperinsulinaemic androgen excess might enable prevention in childhood.

Identification of estrogen target genes during zebrafish embryonic development through transcriptomic analysis

Estrogen signaling is important for vertebrate embryonic development. Here we have used zebrafish (Danio rerio) as a vertebrate model to analyze estrogen signaling during development. Zebrafish embryos were exposed to 1 µM 17β-estradiol (E2) or vehicle from 3 hours to 4 days post fertilization (dpf), harvested at 1, 2, 3 and 4 dpf, and subjected to RNA extraction for transcriptome analysis using microarrays. Differentially expressed genes by E2-treatment were analyzed with hierarchical clustering followed by biological process and tissue enrichment analysis. Markedly distinct sets of genes were up and down-regulated by E2 at the four different time points. Among these genes, only the well-known estrogenic marker vtg1 was co-regulated at all time points. Despite this, the biological functional categories targeted by E2 were relatively similar throughout zebrafish development. According to knowledge-based tissue enrichment, estrogen responsive genes were clustered mainly in the liver, pancreas and brain. This was in line with the developmental dynamics of estrogen-target tissues that were visualized using transgenic zebrafish containing estrogen responsive elements driving the expression of GFP (Tg(5xERE:GFP)). Finally, the identified embryonic estrogen-responsive genes were compared to already published estrogen-responsive genes identified in male adult zebrafish (Gene Expression Omnibus database). The expressions of a few genes were co-regulated by E2 in both embryonic and adult zebrafish. These could potentially be used as estrogenic biomarkers for exposure to estrogens or estrogenic endocrine disruptors in zebrafish. In conclusion, our data suggests that estrogen effects on early embryonic zebrafish development are stage- and tissue- specific.

Upregulation of fatty acid synthesis and the suppression of hepatic triglyceride lipase as a direct cause of hereditary postprandial hypertriglyceridemia in rabbits

Rabbits with hereditary postprandial hypertriglyceridemia exhibit central obesity and are regarded as a reliable model for metabolic syndrome. This study was performed to gain insight into the affected process of lipid metabolism and into the causative genes of the postprandial hypertriglyceridemia rabbits. Eleven genes that play key roles in lipid metabolism were selected, their mRNA levels were assessed by quantitative PCR, and their expressions were compared among postprandial hypertriglyceridemia rabbits using Japanese white rabbits as the control. Two genes appeared to be in causal connection with postprandial hypertriglyceridemia, and these were regarded as likely candidates for the pathogenesis. One was the fatty acid synthase gene, which had an expression constitutively higher in postprandial hypertriglyceridemia rabbits than in Japanese white rabbits during the fasting state and reached quite high levels after feeding. The other was the gene for hepatic triglyceride lipase with an expression that was approximately one order lower than that found in the Japanese white rabbits. The low plasma hepatic triglyceride lipase activities were consistent with the low levels of the transcript in the livers of the postprandial hypertriglyceridemia rabbits. Thus, elevated fatty acid synthesis and defected lipid hydrolysis together would cause the postprandial hypertriglyceridemia in postprandial hypertriglyceridemia rabbits.

The effects of old, new and emerging medicines on metabolic aberrations in PCOS

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age that is associated with significant adverse short- and long-term health consequences. Multiple metabolic aberrations, such as insulin resistance (IR) and hyperinsulinaemia, high incidence of impaired glucose tolerance, visceral obesity, inflammation and endothelial dysfunction, hypertension and dyslipidemia are associated with the syndrome. Assessing the metabolic aberrations and their long term health impact in women with PCOS is challenging and becomes more important as therapeutic interventions currently available for the management of PCOS are not fully able to deal with all these consequences. Current therapeutic management of PCOS has incorporated new treatments resulting from the better understanding of the pathophysiology of the syndrome. The aim of this review is to summarize the effect of old, new and emerging therapies used in the management of PCOS, on the metabolic aberrations of PCOS.

Increased leukocyte ABCA1 gene expression in post-menopausal women on hormone replacement therapy

OBJECTIVE

The ATP binding cassette A1 (ABCA1) is a key participant in the reverse cholesterol process whereby mediates cholesterol efflux directly to HDL particles. The aim of this study was to investigate whether long-term treatment with conventional hormone replacement therapy (HRT) in post-menopausal women could affect their leukocytes ABCA1 expression. Changes in various serum lipids and lipoprotein fractions were also investigated.

MATERIAL AND METHODS

A total of 60 non-obese normolipidaemic post-menopausal women treated with oral oestrogen together with progestin therapy for 3 months were selected. Leukocytes ABCA1 gene expression and serum lipid and lipoprotein concentrations were measured at the start and end of the HRT.

RESULTS

HRT led to significant increases in HDL cholesterol (P = 0.001) and apoA-I (P = 0.046) and significant decrease in apoB (P = 0.049) and LDL cholesterol (P = 0.022) when compared with the baseline levels. Analysis of leukocytes ABCA1 mRNA showed a significant increase in ABCA1 gene expression after HRT (P = 0.001). There was also a significant inverse association (r =  -0.28, P = 0.03) between ABCA1 gene expression and log TG/HDL cholesterol changes related to HRT.

CONCLUSION

The beneficial cardiovascular effects of HRT could be explained, at least in part, by increasing the ABCA1 gene expression.

Serum 2-methoxyestradiol, an estrogen metabolite, is positively associated with serum HDL-C in a population-based sample

Serum HDL cholesterol (HDL-C) is inversely associated with coronary artery disease, ischemic stroke, and atherosclerosis in men and women. Among postmenopausal women, oral conjugated equine estrogen (CEE) increases serum HDL-C. This is due to activation of hepatic nuclear estrogen receptors, resulting in increased HDL-C expression, as well as modulation of proteins which metabolize HDL-C. 2-methoxyestradiol (2-MeOE2), an estrogen metabolite, has several vasculoprotective effects and may play a role in HDL-C production. 2-MeOE2 inhibits HMG-CoA reductase in vitro but no study has examined the relationship between serum 2-MeOE2 and serum HDL-C. A population-based sample provided information regarding demographic characteristics and use of antihyperlipidemic medications. Serum was analyzed for 17β-estradiol (E2), estrogen metabolites (EMs), and lipoproteins. Results included serum EM data from 51 men and 47 postmenopausal women. Preliminary analysis revealed no correlation between 2-MeOE2 and serum HDL-C in men so the current analysis includes only women (N = 40) with no missing demographic, medication, EM, or lipoprotein data. Linear regression revealed that serum 2-MeOE2 and antihyperlipidemic medications were positively associated with serum HDL-C (β = 0.276, P = 0.043, and β = 0.307, P = 0.047, respectively) when age, race/ethnicity, and body mass index were held constant. Prospective studies are needed to determine if 2-MeOE2 is causally related to HDL-C in women.

Plasma levels of 27-hydroxycholesterol in humans and mice with monogenic disturbances of high density lipoprotein metabolism

Secretion of 27-hydroxycholesterol (27OHC) from macrophages is considered as an alternative to HDL-mediated reverse transport of excess cholesterol. We investigated 27OHC-concentrations in plasma of humans and mice with monogenic disorders of HDL metabolism. As compared to family controls mutations in the genes for apolipoprotein A-I, ATP binding cassette transporter (ABC) A1 and lecithin:cholesterol acylstransferase (LCAT) were associated with reduced concentrations of both HDL-cholesterol and HDL-27OHC whereas mutations in the genes for cholesterylester transfer protein (CETP), scavenger receptor type BI and hepatic lipase were associated with elevated HDL concentrations of either sterol. Compared to family controls and relative to the concentrations of total 27OHC and cholesterol, lower 27OHC-ester but normal cholesterylester levels were found in HDL of heterozygous LCAT mutation carriers and nonHDL of heterozygous CETP mutation carriers. In family controls, LCAT activity and CETP mass were more strongly correlated with 27OHC-ester than cholesterylester concentrations in HDL and nonHDL, respectively. These findings suggest that the formation and transfer of 27OHC-esters are more sensitive to reduced activities of LCAT and CETP, respectively, than the formation and transfer of cholesterylesters. 27OHC plasma levels were also decreased in apoA-I-, ABCA1- or LCAT-knockout mice but increased in SR-BI-knockout mice. Transplantation of ABCA1- and/or ABCG1-deficient bone marrow into LDL receptor deficient mice decreased plasma levels of 27OHC. In conclusion, mutations or absence of HDL genes lead to distinct alterations in the quantity, esterification or lipoprotein distribution of 27OHC. These findings argue against the earlier suggestion that 27OHC-metabolism in plasma occurs independently of HDL.

Association of polymorphisms in genes involved in lipoprotein metabolism with plasma concentrations of remnant lipoproteins and HDL subpopulations before and after hormone therapy in postmenopausal women

OBJECTIVE

A high degree of inter-individual variability in plasma lipid level response to hormone therapy (HT) has been reported. Variations in the oestrogen receptor alpha gene (ESR1) and in genes involved in lipid metabolism may explain some of the variability in response to HT. Subjects Postmenopausal Caucasian women (n = 208) participating in a placebo-controlled randomized trial of 3.2 years of hormone therapy (HT).

METHODS

Plasma triglyceride (TG), remnant lipoprotein cholesterol (RLP-C), and high-density lipoprotein cholesterol (HDL-C) levels and HDL subpopulations were assessed at baseline and at follow up. Single nucleotide polymorphisms (SNPs) in ESR1 and in the ATP binding cassette A1 (ABCA1), cholesteryl ester transfer protein (CETP), hepatic lipase (LIPC), lipoprotein lipase (LPL), and scavenger receptor class B type I (SRB1) genes were assessed for their association with baseline plasma levels and HT-related changes in levels of RLP-C and HDL subpopulations.

RESULTS

Carriers of the ESR1 PvuII or IVS1-1505 variants had lower plasma TG concentrations and higher plasma HDL-C and alpha-1 and prealpha-1 HDL particle levels at baseline and showed greater increases in HDL-C, apo A-I and alpha-1 particle levels after HT than wild-type carriers. Carriers of the N291S and D9N variants in the LPL gene had significantly higher remnant lipoproteins and lower alpha-2 HDL particle levels at baseline. The CETP TaqIB SNP was a significant determinant of baseline plasma HDL-C and HDL subpopulation profile.

CONCLUSIONS

Single nucleotide polymorphisms in ESR1, CETP and LPL had significant effects on baseline plasma levels of TG-rich and HDL subpopulations. With the exception of ESR1 SNPs, variation in genes involved in lipid metabolism has a very modest effect on lipoprotein response to HT.

Changes in gene expression profile of medaka with acute toxicity of Arochlor 1260, a polychlorinated biphenyl mixture

Differential gene expression profiling was performed with a cDNA microarray in the liver tissue of the medaka fish, Oryzias latipes, after exposure to Arochlor 1260, a polychlorinated biphenyl (PCB) mixture, which is used as a coolant and insulating fluid for transformers and capacitors and is classified as a persistent organic pollutant. Twenty-six differentially expressed candidate genes were identified. The expression of 12 genes was up-regulated and that of 14 genes was down-regulated. These genes are associated with the cytoskeleton, development, endocrine/reproduction, immunity, metabolism, nucleic acid/protein binding, and signal transduction, or are uncategorized. The transcription of molecular biomarkers known to be involved in endocrine disruption (e.g., vitellogenins, choriogenins, and estrogen receptor alpha) was highly up-regulated. The same tendencies in gene expression changes were observed with real-time quantitative PCR (qRT-PCR) analysis, which was conducted to examine 12 selected candidate genes. These genes could be used as molecular biomarkers for biological responses to toxic chemicals, especially endocrine disrupting and carcinogenic chemical contamination in aquatic environments.

The effect of pharmaceutical intervention on lipid profile in polycystic ovary syndrome

The polycystic ovary syndrome (PCOS), a prevalent endocrinopathy of women, has been associated with a clustering of adverse metabolic features, which co-exist with reproductive dysfunction. Lipid abnormalities are very common in lean as well as obese women with PCOS and should be cautiously considered in the therapeutic management of the syndrome. Clinicians should also critically assess the lipidemic effect of pharmaceutical intervention, primarily aimed at hyperandrogenism, anovulation or insulin resistance. Because dyslipidemia may contribute to long-term cardiometabolic and reproductive sequelae in PCOS, it should be considered as an additional therapeutic target when these patients are assigned to appropriate pharmaceutical treatment.

Long-term oral contraceptive treatment, metabolic syndrome and measures of cardiovascular risk in pre-menopausal women: National Health and Nutrition Examination Survey 1999-2004

AIM

Differences in subclinical cardiometabolic measures were examined as a function of oral contraceptive pills (OCP) treatment duration to compare never-treated women with four OCP-treatment groups (<1, 1-5, 5-10 and >10 years).

METHODS

The NHANES (1999-2004) database was used to evaluate 2089 healthy, pre-menopausal women, aged 18-55 years, with or without OCP history, no other hormonal treatment or history of systemic conditions. Outcome measures included body mass, central obesity, blood pressure, glycemia, insulinemia, lipid profile and inflammation. Analyses evaluated differences in prevalence of Metabolic Syndrome (MetS), constituent MetS and other clinical risk criteria, as well as outcome magnitudes. Analyses controlled for demographic and health-related variables, and study-eligible conditions.

RESULTS

Relative to other groups, women with >10 years OCP-use, and to some extent those with 5-10 years treatment, displayed no differences in prevalence of MetS and most risk criteria. Further analysis showed that, relative to women treated for <5 years, those with more prolonged OCP treatment displayed lower body mass and fasting glycemia with higher HDL-c levels, but more elevated LDL-c and total cholesterol.

CONCLUSIONS

The findings of both beneficial and detrimental subclinical cardiometabolic differences with more long-term OCP-treatment reinforces the need to monitor changes in these factors within the context of the treated patient's risk-benefit profile. However, because the magnitude of these differences was small, relative to normative ranges, it may be concluded that OCPs, as used in recent decades, are unlikely to markedly affect cardiometabolic risk.

Lipid profile and inflammatory markers associated with estrogen receptor alpha PvuII and XbaI gene polymorphisms

Estrogen is established to influence lipoprotein metabolism and inflammatory markers. Alternations in estrogen receptor alpha (ESR1) expression and function may affect the role of estrogen in this regard. The aim of this study was to determine whether ESR1 PvuII and XbaI gene polymorphisms have effects on lipoprotein (a) as well as inflammatory variables in an Iranian population. Three hundred and ninety seven consecutive participants (228 men, 57.4%) who were admitted at our center for elective coronary angiography because of symptoms related to coronary artery disease (CAD) were enrolled in our study. Total cholesterol, high-density lipoprotein (HDL)-cholesterol, and triglyceride levels were determined by standard methods using commercial kits. Low-density lipoprotein (LDL)-cholesterol was calculated according to the Friedewald formula. The lipoprotein (a) levels were measured by ELISA method using Biopool kit, and the CRP concentrations were determined by Latex Immunoturbidometry. The presence of PvuII and XbaI polymorphisms within the ESR gene were analyzed using polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP). The frequency of homozygous and heterozygous were 25.9% and 50.1%, for PvuII genotypes, and the frequency was 23.7% and 48.6%, for XbaI genotypes, respectively. After adjusting for CAD and age, no impacts of ESR1 PvuII and XbaI polymorphisms were found on lipid profile, lipoprotein (a) level, and quantitative CRP either in total population or in subgroups stratified by gender. In conclusion, our data demonstrate that ESR1 PvuII and XbaI gene polymorphisms did not seem to have an effect on lipoprotein metabolism or on inflammatory variables such as CRP.

Contraceptive hormone use and cardiovascular disease

Contraceptive hormones, most commonly prescribed as oral contraceptives (OCs), are a widely utilized method to prevent ovulation, implantation, and, therefore, pregnancy. The Women's Health Initiative demonstrated cardiovascular risk linked to menopausal hormone therapy among women without pre-existing cardiovascular disease, prompting a review of the safety, efficacy, and side effects of other forms of hormone therapy. A variety of basic science, animal, and human data suggests that contraceptive hormones have antiatheromatous effects; however, relatively less is known regarding the impact on atherosclerosis, thrombosis, vasomotion, and arrhythmogenesis. Newer generation OC formulations in use indicate no increased myocardial infarction risk for current users, but a persistent increased risk of venous thromboembolism. There are no cardiovascular data available for the newest generation contraceptive hormone formulations, including those that contain newer progestins that lower blood pressure, as well as the nonoral routes (transdermal and vaginal). Current guidelines indicate that, as with all medication, contraceptive hormones should be selected and initiated by weighing risks and benefits for the individual patient. Women 35 years and older should be assessed for cardiovascular risk factors including hypertension, smoking, diabetes, nephropathy, and other vascular diseases, including migraines, prior to use. Existing data are mixed with regard to possible protection from OCs for atherosclerosis and cardiovascular events; longer-term cardiovascular follow-up of menopausal women with regard to prior OC use, including subgroup information regarding adequacy of ovulatory cycling, the presence of hyperandrogenic conditions, and the presence of prothrombotic genetic disorders is needed to address this important issue.

Oral but not transdermal estrogen replacement therapy changes the composition of plasma lipoproteins

The role of hormone replacement therapy and estrogen replacement therapy (ERT) in cardiovascular disease prevention has not been unambiguously defined yet. The metabolic effects of estrogens may vary depending upon the route of administration. Therefore, we compared the impact of unopposed oral or transdermal ERT on plasma lipids and lipoproteins in 41 hysterectomized women. This was an open-label, randomized, crossover study (with 2 treatments and 2 periods). The 41 hysterectomized women were randomized to receive oral or transdermal 17beta-estradiol in the first or second of two 12-week study periods. Plasma lipid and lipoprotein levels were assayed before and after each treatment using standard automated methods. Lipid content of lipoprotein subclasses was assessed by sequential ultracentrifugation. The atherogenic index of plasma (AIP) was calculated as log(triglyceride [TG]/high-density lipoprotein [HDL] cholesterol). The difference between the 2 forms of administration was tested using a linear mixed model. The change from baseline for each of the forms was tested using paired t test. Oral ERT resulted in a significant increase in HDL cholesterol and apolipoprotein A-I levels, whereas it significantly decreased total and low-density lipoprotein (LDL) cholesterol and increased TG concentrations. Transdermal ERT had no such effect. Oral ERT led to a significant TG enrichment of HDL (0.19 +/- 0.06 vs 0.27 +/- 0.07 mmol/L, P < .001) and LDL particles (0.23 +/- 0.08 vs 0.26 +/- 0.10 mmol/L, P < .001) compared with baseline, whereas transdermal therapy did not have any effect on lipoprotein subclasses composition. The difference between the 2 treatments was statistically significant for HDL-TG and LDL-TG (0.27 +/- 0.07 vs 0.19 +/- 0.05 mmol/L, P < .001 and 0.26 +/- 0.10 vs 0.22 +/- 0.07 mmol/L, P< .001, respectively). The transdermal but not oral ERT significantly reduced the AIP compared with baseline (-0.17 +/- 0.26 vs -0.23 +/- 0.25, P = .023), making the difference between the therapies statistically significant (-0.23 +/- 0.25 vs -0.18 +/- 0.22, P = .017). Oral administration of ERT resulted in TG enrichment of LDL and HDL particles. Transdermal ERT did not change the composition of the lipoproteins and produced a significant improvement of AIP. Compared with transdermal ERT, orally administered ERT changes negatively the composition of plasma lipoproteins.

Specific adaptations of estrogen receptor alpha and beta transcripts in liver and heart after endurance training in rats

Estrogens exert their biological roles mainly through estrogen receptors (ER) that function as ligand-activated transcription factors. ER content in a cell is regulated by many factors and is decisive for estrogen action. The purpose of the present study was to investigate the influence of an 8-wk endurance training program on ER expression in the liver, right atrium (RA), and left ventricle (LV) of intact and ovariectomized (Ovx) rats. We measured ERalpha and ERbeta mRNA content by reverse transcription-polymerase chain reaction (RT-PCR). We found an important increase in ERalpha mRNA levels in the liver (300%; P < 0.01) and in ERbeta mRNA levels in the RA (200%; P < 0.05), and a marked decrease in ERalpha (80%; P < 0.01) and ERbeta (40%; P < 0.05) transcripts content in the LV of intact rats after endurance training. On the other hand, ERalpha mRNA levels were depressed by 50% (P < 0.01) in the liver, and increased by 60% (P < 0.01) in LV of Ovx rats after exercise training. These results first indicate that endurance training is associated with modifications of ER transcripts levels in the liver, LV, and RA of female rats. More specifically, these effects are tissue and isoform-specific and the direction of the response (increase or decrease) is different in intact and Ovx rats. It is suggested that some of the adaptations to endurance training in liver and heart may be mediated by an ER-dependent mechanism.

Regulation of human CYP27A1 by estrogens and androgens in HepG2 and prostate cells

The regulation of the human CYP27A1 gene by estrogens and androgens was studied in human liver-derived HepG2 and prostate cells. Our results show that the promoter activity, enzymatic activity and mRNA levels of CYP27A1 in HepG2 cells are downregulated by estrogen in presence of ERalpha or ERbeta. Similar effects by estrogen were found in RWPE-1 prostate cells. In contrast, estrogen markedly upregulated the transcriptional activity of CYP27A1 in LNCaP prostate cancer cells. 5alpha-Dihydrotestosterone and androgen receptor upregulated the transcriptional activity of CYP27A1 in HepG2 cells. Progressive deletion experiments indicate that the ERbeta-mediated effects in HepG2 and LNCaP cells are conferred to the same region (-451/+42) whereas ERalpha-mediated effects on this promoter are more complex. The results indicate that the stimulating effect of androgen in HepG2 cells is conferred to a region upstream from -792 in the CYP27A1 promoter. In summary, we have identified the human CYP27A1 gene as a target for estrogens and androgens. The results imply that expression of CYP27A1 may be affected by endogenous sex hormones and pharmacological compounds with estrogenic or androgenic effects.

Lipid, haemostatic and inflammatory variables in relation to the estrogen receptor alpha (ESR1) PvuII and XbaI gene polymorphisms

BACKGROUND

Estrogen is known to affect lipoprotein metabolism, the haemostatic system and inflammatory markers. Our aim was to determine whether estrogen receptor alpha (ESR1) PvuII and XbaI gene polymorphisms can influence lipid, haemostatic and inflammatory variables in healthy Caucasian women and men of reproductive age.

METHODS

58 healthy women (aged between 18 and 45 years) and 55 healthy men (aged between 21 and 45 years) of reproductive age were enrolled in our study. FSH levels, lipid (total cholesterol, triglyceride, HDL cholesterol, lipoprotein(a), apo A-I, apo B), haemostatic (prothrombin time, activated partial thromboplastin time (aPTT), thrombin time, fibrinogen, factor V, VII, VIII, protein C, protein S, antithrombin III) and inflammatory (CRP) variables were measured on autoanalyzers using commercially available kits. Serum VLDL and LDL cholesterol concentrations were calculated with the equation of Friedewald. The ESR1 PvuII and XbaI genotypes were determined with PCR-RFLP method.

RESULTS

In the total group, the ESR1 XbaI GG genotype carriers had significantly higher serum lipoprotein(a) concentrations than the AA or AG genotype carriers. Serum total cholesterol concentrations were significantly higher in healthy women with the PvuII CC genotype than in those with the TT or TC genotypes, whereas healthy women with the GG genotype of the ESR1 XbaI polymorphism had significantly higher serum total cholesterol and LDL cholesterol levels compared to those with the AA or AG genotypes. No other effects of the ESR1 PvuII and XbaI polymorphisms were found on the investigated lipid, haemostatic and inflammatory variables either in the total group or in women and men separately.

CONCLUSIONS

The ESR1 PvuII and XbaI gene polymorphisms seem to affect lipoprotein metabolism in healthy subjects of peak reproductive age. However, further studies are needed to determine the molecular mechanisms by which the two polymorphisms could influence serum lipid levels.

Transcriptional regulation of the human hepatic lipase (LIPC) gene promoter

Hepatic lipase (HL) plays a key role in the metabolism of plasma lipoproteins, and its level of activity requires tight regulation, given the association of both low and high levels with atherosclerosis and coronary artery disease. However, little is known about the factors responsible for HL expression. Here, we report that the human hepatic lipase gene (LIPC) promoter is regulated by hepatocyte nuclear factor 4alpha (HNF4alpha), peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha), apolipoprotein A-I regulatory protein-1 (ARP-1), and hepatocyte nuclear factor 1alpha (HNF1alpha). Reporter analysis showed that HNF4alpha directly regulates the LIPC promoter via two newly identified direct repeat elements, DR1 and DR4. PGC-1alpha is capable of stimulating the HNF4alpha-dependent transactivation of the LIPC promoter. ARP-1 displaces HNF4alpha from the DR1 site and blocks its ability to activate the LIPC promoter. Induction by HNF1alpha requires the HNF1 binding site and upon cotransfection with HNF4alpha leads to an additive effect. In addition, the in vivo relevance of HNF4alpha in LIPC expression is shown by the ability of the HNF4alpha antagonist Medica 16 to repress endogenous LIPC mRNA expression. Furthermore, disruption of Hnf4alpha in mice prevents the expression of HL mRNA in liver. The overall effect these transcription factors have on HL expression will ultimately depend on the interplay between these various factors and their relative intracellular concentrations.

Estrogen receptor inhibits interleukin-6 gene expression by disruption of nuclear factor kappaB transactivation

The estrogen receptor (ER) suppresses interleukin-6 (IL-6) gene expression through interaction with nuclear factor kappaB (NF-kappaB) in a hormone-dependent manner. Classic ER binding to DNA is not required and the mechanism of repression is unclear. Previously reported studies suggest that the interference of NF-kappaB binding to DNA by ER may play an important role. An alternative model for repression would be the disruption of NF-kappaB transactivation. In the present study, gel shift assays were used to examine the binding of RelA and p50 dimers to the IL-6 promoter in the presence of ER. The effect of ER on NF-kappaB transactivation was studied independent of NF-kappaB binding to DNA using the mammalian one-hybrid system. ER had little effect on the binding of homodimers or heterodimers of RelA and p50 to the IL-6 promoter. In transfection experiments, both ERalpha and ERbeta inhibited NF-kappaB-mediated expression in a hormone dependent manner with repression also dependent upon dimerization of RelA with p50. Mutant ER that is unable to transactivate failed to repress NF-kappaB expression, but deletion of the N-terminal portion of the receptor had no effect. Taken together, these results suggest that the disruption of NF-kappaB-mediated transactivation plays a significant role in ER inhibition of IL-6 gene expression.