Estrogen receptor beta: tissue distribution and the still largely enigmatic physiological function

Mechanisms of Action of Phytoestrogens and Their Role in Familial Adenomatous Polyposis

Familial adenomatous polyposis (FAP) is a rare disease characterized by the development of adenomatous polyps in the colon and rectum already in adolescence. If left untreated, patients develop colorectal cancer (CRC) with a 100% probability. To date, the gold standard of FAP management is surgery, which is associated with morbidity and mortality. A chemopreventive agent capable of delaying, preventing and reversing the development of CRC has been sought. Several classes of drugs have been used but to date no chemopreventive drug has been found for the management of this disease. In recent years, the importance of estrogen receptors in FAP and CRC, particularly the β subtype, has emerged. Indeed, the expression of the latter is strongly reduced in adenomatous polyps and CRC and is inversely correlated with the aggressiveness of the disease. Since phytoestrogens have a high affinity for this receptor, they have been suggested for use as chemopreventive agents in FAP and CRC. A combination of phytoestrogens and insoluble fibres has proved particularly effective. In this review, the various mechanisms of action of phytoestrogens were analyzed and the effectiveness of using phytoestrogens as an effective chemopreventive strategy was discussed.

Uterine Uptake of Estrogen and Progestogen-Based Radiotracers in Rhesus Macaques with Endometriosis

PURPOSE

Endometriosis is an estrogen-dependent disorder of menstruating primates where tissues similar to the inner lining of the uterus exist "ectopically" outside of the uterus. The ectopic endometrium, like the endometrium within the uterus, expresses estrogen receptors (ER) and progesterone receptors (PR) and undergoes hormone-dependent cell proliferation and bleeding each menstrual cycle. The goal of this study was to conduct abdominopelvic positron emission tomography (PET) scans with computed tomography (CT) imaging of rhesus macaques (Macaca mulatta) using radiotracers that target ER and PR [16α-[18F]fluoroestradiol (FES) and 12-[18F]fluoro-furanyl-nor-progesterone (FFNP)] in individuals with and without endometriosis. We also aimed to determine if menstrual cycle phase and/or the presence of endometriosis affected the uptake of these radiotracers.

PROCEDURES

Rhesus macaques with either clinically diagnosed endometriosis (n = 6) or no endometriosis (n = 4) underwent PET/CT scans with FES. A subset of the animals also underwent PET/CT scans with FFNP. Standard uptake values corrected for body weight (SUVs) were obtained for each radiotracer in target and background tissues (e.g., intestinal). We performed repeated measure analysis of variance tests to determine how uterine and background uptake differed with scan time, phase of the menstrual cycle, and disease state.

RESULTS

Abdominopelvic PET/CT could not resolve small, individual endometriotic lesions. However, macaques with endometriosis displayed higher uterine uptake compared to those without the disorder. Radiotracer uptake differed by menstrual cycle phase with increased uterine uptake of both radiotracers in the proliferative phase of the menstrual cycle. Background intestinal uptake of FFNP increased over time after infusion, but only during the proliferative phase.

CONCLUSIONS

PET/CT with FES and FFNP support the concept that ER and PR levels are altered in individuals with endometriosis. This highlights the impact of the disease on typical reproductive tract function and may provide a novel pathway for the identification of individuals with endometriosis.

Genome-wide association study for body weight and feed consumption traits in Japanese quail using Bayesian approaches

The aim of this study was to perform a genome-wide association study (GWAS) based on Bayes A and Bayes B statistical methods to identify genomic loci and candidate genes associated with body weight gain, feed intake, and feed conversion ratio in Japanese quail. For this purpose, genomic data obtained from Illumina iSelect 4K quail SNP chip were utilized. After implementing various quality control steps, genotype data from a total of 875 birds for 2,015 SNP markers were used for subsequent analyses. The Bayesian analyses were performed using hibayes package in R (version 4.3.1) and Gibbs sampling algorithm. The results of the analyses showed that Bayes A accounted for 11.43, 11.65, and 11.39% of the phenotypic variance for body weight gain, feed intake, and feed conversion ratio, respectively, while the variance explained by Bayes B was 7.02, 8.61, and 6.48%, respectively. Therefore, in the current study, results obtained from Bayes A were used for further analyses. In order to perform the gene enrichment analysis and to identify the functional pathways and classes of genes that are over-represented in a large set of genes associated with each trait, all markers that accounted for more than 0.1% of the phenotypic variance for each trait were used. The results of this analysis revealed a total of 23, 38, and 14 SNP markers associated with body weight gain, feed intake, and feed conversion ratio in Japanese quail, respectively. The results of the gene enrichment analysis led to the identification of biological pathways (and candidate genes) related to lipid phosphorylation (TTC7A gene) and cell junction (FGFR4 and FLRT2 genes) associated with body weight gain, calcium signaling pathway (ADCY2 and CAMK1D genes) associated with feed intake, and glycerolipid metabolic process (LIPC gene), lipid metabolic process (ADGRF5 and ESR1 genes), and glutathione transferase (GSTK1 gene) associated with feed conversion ratio. Overall, the findings of this study can provide valuable insights into the genetic architecture of growth and feed consumption traits in Japanese quail.

Sex hormone signaling and regulation of immune function

Immune responses to antigens, including innocuous, self, tumor, microbial, and vaccine antigens, differ between males and females. The quest to uncover the mechanisms for biological sex differences in the immune system has intensified, with considerable literature pointing toward sex hormonal influences on immune cell function. Sex steroids, including estrogens, androgens, and progestins, have profound effects on immune function. As such, drastic changes in sex steroid concentrations that occur with aging (e.g., after puberty or during the menopause transition) or pregnancy impact immune responses and the pathogenesis of immune-related diseases. The effect of sex steroids on immunity involves both the concentration of the ligand and the density and distribution of genomic and nongenomic receptors that serve as transcriptional regulators of immune cellular responses to affect autoimmunity, allergy, infectious diseases, cancers, and responses to vaccines. The next frontier will be harnessing these effects of sex steroids to improve therapeutic outcomes.

Uterine uptake of estrogen and progestogen-based radiotracers in rhesus macaques with endometriosis

Purpose

Few investigations have examined the uptake of radiotracers that target the prominent sex-steroid receptors in the uterus across the menstrual cycle and with disease state. We aimed to determine if uptake of the radiotracers that target estrogen and progesterone receptors (ER and PR) differ with the presence of endometriosis and/or across the menstrual cycle. We performed PET and computed tomography (CT) imaging procedures on rhesus macaques (Macaca mulatta) using 16α-[18F]fluoroestradiol (FES) and 21-[18F]fluoro-furanyl-nor-progesterone (FFNP) in individuals with and without endometriosis in the proliferative and secretory phases of the menstrual cycle.

Procedures

Macaques with either clinically diagnosed endometriosis (n = 6) or no endometriosis (n = 4) underwent abdominopelvic PET/CT scans with FES. A subset of these animals also underwent PET/CT scans with FFNP. Standard uptake values corrected for body weight (SUVbw) were obtained for each radiotracer in target and background tissues (i.e., intestinal and muscle). We performed repeated measure analysis of variance tests to determine how uterine and background uptake differed with scan time, phase of the menstrual cycle, and disease state.

Results

PET/CT could not resolve small, individual endometriotic lesions. However, uterine uptake of both radiotracers was elevated in the proliferative phase compared to the secretory phase of the menstrual cycle. Intestinal uptake exhibited greater variation during the proliferative phase compared to the secretory phase. Further, intestinal uptake of FFNP increases as the scan progresses, but only during the proliferative phase. Muscle uptake did not differ with menstrual phase or radiotracer type. Lastly, macaques with endometriosis displayed higher uterine uptake of FES compared to those without endometriosis.

Conclusions

PET/CT with FES and FFNP support the concept that ER and PR levels are altered in individuals with endometriosis. This highlights the impact of the disease on typical reproductive tract function and may provide a novel pathway for the identification of individuals with endometriosis.

Expression of Androgen and Estrogen Receptors in the Human Lacrimal Gland

Lacrimal gland dysfunction causes dry eye disease (DED) due to decreased tear production. Aqueous-deficient DED is more prevalent in women, suggesting that sexual dimorphism of the human lacrimal gland could be a potential cause. Sex steroid hormones are a key factor in the development of sexual dimorphism. This study aimed to quantify estrogen receptor (ER) and androgen receptor (AR) expression in the human lacrimal gland and compare it between sexes. RNA was isolated from 35 human lacrimal gland tissue samples collected from 19 cornea donors. AR, ERα, and ERβ mRNA was identified in all samples, and their expression was quantified using qPCR. Immunohistochemical staining was performed on selected samples to evaluate protein expression of the receptors. ERα mRNA expression was significantly higher than the expression of AR and ERβ. No difference in sex steroid hormone (SSH) receptor mRNA expression was observed between sexes, and no correlation was observed with age. If ERα protein expression is found to be concordant with mRNA expression, it should be investigated further as a potential target for hormone therapy of DED. Further research is needed to elucidate the role of sex steroid hormone receptors in sex-related differences of lacrimal gland structure and disease.

The Co-Expression of Estrogen Receptors ERα, ERβ, and GPER in Endometrial Cancer

Estrogens have important roles in endometrial cancer (EC) and exert biological effects through the classical estrogen receptors (ERs) ERα and ERβ, and the G-protein-coupled ER, GPER. So far, the co-expression of these three types of ERs has not been studied in EC. We investigated ERα, ERβ, GPER mRNA and protein levels, and their intracellular protein distributions in EC tissue and in adjacent control endometrial tissue. Compared to control endometrial tissue, immunoreactivity for ERα in EC tissue was weaker for nuclei with minor, but unchanged, cytoplasmic staining; mRNA and protein levels showed decreased patterns for ERα in EC tissue. For ERβ, across both tissue types, the immunoreactivity was unchanged for nuclei and cytoplasm, although EC tissues again showed lower mRNA and protein levels compared to adjacent control endometrial tissue. The immunoreactivity of GPER as well as mRNA levels of GPER were unchanged across cancer and control endometrial tissues, while protein levels were lower in EC tissue. Statistically significant correlations of estrogen receptor α (ESR1) versus estrogen receptor β (ESR2) and GPER variant 3,4 versus ESR1 and ESR2 was seen at the mRNA level. At the protein level studied with Western blotting, there was significant correlation of ERα versus GPER, and ERβ versus GPER. While in clinical practice the expression of ERα is routinely tested in EC tissue, ERβ and GPER need to be further studied to examine their potential as prognostic markers, provided that specific and validated antibodies are available.

Estrogen receptor agonists induce anti‑edema effects by altering α and β estrogen receptor gene expression

The present study aimed to examine whether the attenuation of estrogen receptor expression is prevented by propyl pyrazole triol (PPT), an agonist for estrogen receptor α (ERα) or and diarypropiolnitrile (DPN), an agonist for estrogen receptor β (ERβ) after traumatic brain injury (TBI). The tests performed on ovariectomized female Wistar rats included sham group, vehicle group, and treated groups: PPT, DPN, and PPT+DPN 30 minutes after TBI. Blood‑brain barrier (BBB) disruption and brain water content were estimated. RT‑PCR and\r\nwestern blotting were utilized to evaluate ESR1 and ESR2 gene and protein expression. The data indicated that PPT, DPN, and PPT+DPN attenuated TBI‑induced brain edema. Also, BBB disruption after TBI was prevented in PPT, DPN, and PPT+DPN‑treated TBI animals. Estrogen agonist‑treated animals showed a significant elevation in Esr1 mRNA and protein expression levels in the brain tissue of TBI rats. In addition, the data indicated a significant elevation of Esr2 mRNA and protein expression levels in the brain tissue of estrogen agonist‑treated TBI rats. The data shows that both ESR1 and ESR2 agonists can enhance ER mRNA and protein levels in TBI animals' brain. It appears that this effect contributes to the neuroprotective function of ER agonists.

Zearalenone and the Immune Response

Zearalenone (ZEA) is an estrogenic fusariotoxin, being classified as a phytoestrogen, or as a mycoestrogen. ZEA and its metabolites are able to bind to estrogen receptors, 17β-estradiol specific receptors, leading to reproductive disorders which include low fertility, abnormal fetal development, reduced litter size and modification at the level of reproductive hormones especially in female pigs. ZEA has also significant effects on immune response with immunostimulatory or immunosuppressive results. This review presents the effects of ZEA and its derivatives on all levels of the immune response such as innate immunity with its principal component inflammatory response as well as the acquired immunity with two components, humoral and cellular immune response. The mechanisms involved by ZEA in triggering its effects are addressed. The review cited more than 150 publications and discuss the results obtained from in vitro and in vivo experiments exploring the immunotoxicity produced by ZEA on different type of immune cells (phagocytes related to innate immunity and lymphocytes related to acquired immunity) as well as on immune organs. The review indicates that despite the increasing number of studies analyzing the mechanisms used by ZEA to modulate the immune response the available data are unsubstantial and needs further works.

Dietary isoflavone-induced, estrogen receptor-β-mediated proliferation of Caco-2 cells is modulated by gallic acid

Dietary isoflavones and their biotransformation products (from food fermentation) are estrogen mimics which activate estrogen receptors (ER)α and ERβ. In silico molecular modelling is used to determine theoretical binding energies of genistein, daidzein and hydroxylated biotransformation products, and to investigate structure-binding energy relationships with ERβ. Results suggest that ligand hydroxyl arrangement determines binding energy and influences binding affinity. Caco-2 cells (ERβ expressing) are used to study the proliferative effect of genistein, daidzein and their hydroxylated biotransformation products. Isoflavones/biotransformation products showed weaker enhancement of Caco-2 proliferation than 17β-estradiol. The EC₅₀s of isoflavones/biotransformation products agreed with in silico-predicted binding affinity order. Hydroxylated biotransformation products studied showed greater Caco-2 proliferative effects than the parent isoflavones except 8-hydroxygenistein, probably due to unfavourable ERβ interactions caused by 8-hydroxygenistein's extra hydroxyl. Caco-2 pre-treatment with UDP-glucose dehydrogenase inhibitor gallic acid promoted genistein/8-hydroxygenistein-mediated proliferation. This is probably due to a reduced isoflavone glucuronidation to form low estrogenicity glucuronides. Findings are discussed in the context of dietary isoflavones/gallic acid and effects on proliferation of ERβ-expressing gut cancer cells.

The Effects of Menopause on Neuromuscular Parameters of the Rat Vocal Folds

OBJECTIVES/HYPOTHESIS

Menopause adversely affecs power and endurance of the limb muscles. However, despite clinical observations that menopause corresponds to negative changes of the voice, the direct effects of estrogen deprivation on the thyroarytenoid muscles are unknown. The purpose of this study was to investigate the effects of estrogen deprivation via ovariectomy on three neuromuscular parameters of the thyroarytenoid muscles using a rat model.

STUDY DESIGN

Animal model.

METHODS

Cryosections of vocal folds of 20 (10 control and 10 ovariectomized) female rats were stained to label neuromuscular junctions, fiber size, or parvalbumin levels using immunohistochemical techniques and compared between experimental groups.

RESULTS

The neuromuscular junctions, thyroarytenoid fiber sizes, and parvalbumin levels of the vocal folds were similar between experimental groups.

CONCLUSIONS

The loss of estrogen did not change neuromuscular parameters of the vocal folds of adult female rats; therefore, vocal changes within the outer vibratory layers of the vocal folds may primarily be responsible for clinically observed menopausal vocal changes.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:1343-1348, 2021.

Sex and Gender Disparities in Melanoma

Worldwide, the total incidence of cutaneous melanoma is higher in men than in women, with some differences related to ethnicity and age and, above all, sex and gender. Differences exist in respect to the anatomic localization of melanoma, in that it is more frequent on the trunk in men and on the lower limbs in women. A debated issue is if-and to what extent-melanoma development can be attributed to gender-specific behaviors or to biologically intrinsic differences. In the search for factors responsible for the divergences, a pivotal role of sex hormones has been observed, although conflicting results indicate the involvement of other mechanisms. The presence on the X chromosome of numerous miRNAs and coding genes playing immunological roles represents another important factor, whose relevance can be even increased by the incomplete X chromosome random inactivation. Considering the known advantages of the female immune system, a different cancer immune surveillance efficacy was suggested to explain some sex disparities. Indeed, the complexity of this picture emerged when the recently developed immunotherapies unexpectedly showed better improvements in men than in women. Altogether, these data support the necessity of further studies, which consider enrolling a balanced number of men and women in clinical trials to better understand the differences and obtain actual gender-equitable healthcare.

Association between oestrogen receptors and female temporomandibular disorders

Objective: To evaluate if temporomandibular disorders (TMDs) are associated with genetic polymorphisms in ESR1 and ESR2, which are genes encoding oestrogen receptor alpha (ERα) and beta (ERβ). Also, we included an animal model to check if ERα and ERβ are expressed in the temporomandibular joint (TMJ) during adolescence.Materials and methods: A total of 139 teenagers and 93 adults were diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMDs). The DNA was collected and the markers ESR1 and ERS2 were genotyped. Additionally, immunohistochemistry was performed in TMJ tissues from female Wistar rats during puberty. All data were submitted to statistical analysis with confidence interval of 95%.Results: Teenagers presented more disc displacement and arthralgia than adults (p < .05). The genetic polymorphism rs1256049 in ESR2 was associated with disc displacement (p = .040; OR = 10.50/95%CI 1.17-98.74) and arthralgia (p = .036; OR = 7.20/95%CI 1.10-46.88) in adults. The ERα and ERβ are expressed in rat TMJ tissues.Conclusions: We provide evidence that ESR2 is associated with TMD and could be a genetic marker for this condition in adult women. Furthermore, oestrogens receptors are presented in TMJ of adolescent female rats.

Loss of Estrogen Receptors is Associated with Increased Tumor Aggression in Laryngeal Squamous Cell Carcinoma

Laryngeal squamous cell carcinoma (LSCC) responds to 17β-estradiol via estrogen-receptor (ER, transcribed from ESR1) dependent mechanisms, but is not recognized as a hormonally responsive cancer. 17β-estradiol production by LSCC cell lines UM-SCC-11A and UM-SCC-12 was examined. Wild type (WT) and ESR1-silenced LSCC cultures and xenografts were examined for 17β-estradiol responsiveness in vivo. 14 LSCC and surrounding epithelial samples at various pathological stages were obtained from patients; ERα and ERβ expression were verified using data from the total cancer genome atlas. UM-SCC-11A and UM-SCC-12 both produce 17β-estradiol, but only UM-SCC-12, not UM-SCC-11A, xenograft tumors grow larger in vivo in response to systemic 17β-estradiol treatments. ERα66 and ERα36 expression inversely correlated with clinical cancer stage and tumor burden. LSCC ERα66 expression was higher compared to surrounding epithelia in indolent samples but lower in aggressive LSCC. ERβ expression was highly variable. High ESR1 expression correlated with improved survival in LSCC. Loss of ERα66 expression inversely correlated with prognosis in LSCC. ERα66 may be a histopathological marker of aggression in LSCC.

Acute Exposure to Zearalenone Disturbs Intestinal Homeostasis by Modulating the Wnt/β-Catenin Signaling Pathway

The mycotoxin zearalenone (ZEN), which frequently contaminates cereal-based human food and animal feed, is known to have an estrogenic effect. The biological response associated with exposure to ZEN has rarely been reported in organs other than the reproductive system. In the intestine, several studies suggested that ZEN might stimulate molecular changes related to the activation of early carcinogenesis, but the molecular mechanisms behind these events are not yet known. In this study, we investigated gene expression and changes in protein abundance induced by acute exposure to ZEN in the jejunum of castrated male pigs using an explant model. Our results indicate that ZEN induces the accumulation of ERα but not ERβ, modulates Wnt/β-catenin and TGF-β signaling pathways, and induces molecular changes linked with energy sensing and the antimicrobial activity without inducing inflammation. Our results confirm that the intestine is a target for ZEN, inducing changes that promote cellular proliferation and could contribute to the onset of intestinal pathologies.

Possible association between craniofacial dimensions and genetic markers in ESR1 and ESR2

OBJECTIVE

To investigate the association of genetic markers in ESR1 and ESR2 with craniofacial measurements.

DESIGN

Cross-sectional study.

SETTING

School of Dentistry of Ribeirão Preto, University of São Paulo.

PARTICIPANTS

A total of 146 biologically unrelated, self-reported Caucasian Brazilians with no syndromic conditions were included.

METHODS

Sagittal and vertical measurements (ANB, S-N, Ptm'-A', Co-Gn, Go-Pg, N-Me, ANS-Me, S-Go and Co-Go) from lateral cephalograms were examined for craniofacial evaluation. DNA was extracted from saliva and genetic markers in ESR1 (rs2234693 and rs9340799) and in ESR2 (rs1256049 and rs4986938) were analysed by real-time polymerase chain reaction. Hardy-Weinberg equilibrium was evaluated using the Chi-square test within each marker. The associations between craniofacial dimensions and genotypes were analysed by linear regression and adjusted by sex and age. The established alpha was 5%.

RESULTS

Individuals carrying CC in ESR1 rs2234693 had a decrease of -3.146 mm in ANS-Me (P = 0.044). In addition, rs4986938 in ESR2 was associated with S-N measurement (P = 0.009/ ß = -3.465). This marker was also associated with Go-Pg measurement, in which the CC genotype had a decrease of -3.925 mm in the length of the mandibular body (P = 0.043).

CONCLUSION

The present study suggests that in ESR1 and ESR2 are markers for variations in the craniofacial dimensions. However, further research should confirm the results.

Estrogen signaling and estrogen receptors as prognostic indicators in laryngeal cancer

Laryngeal squamous cell carcinoma (LSCC) has been shown to respond to 17β-estradiol. However, the presence and characterization of estrogen receptors (ER) and other sex hormone receptors in LSCC are still being determined. Sex hormone receptors and the way sex hormones impact LSCC tumors are important for understanding which patients would benefit from hormone therapies, such as anti-estrogen therapies. This information also has prognostic value, as there may be a correlation between ER profiles and LSCC aggression. Recent work by our team and others has shown that the canonical ER, estrogen receptor α (ERα), and its splice variant ERα36, are important modulators of estrogen signaling in LSCC. This review describes some common 17β-estradiol signaling pathways, and explains how these signaling pathways might control LSCC tumor growth. We also show that loss of ERα, but not ERα36, imbues LSCC with enhanced aggression, a pattern which has previously only been observed in breast cancer. We make a case for using ERα as a tumorigenic modulator and pathogenic marker in LSCC on par with the use of ERα as a prognostic marker in breast cancer.

Estrogen Receptors and Melanoma: A Review

In the last three decades cutaneous melanoma has been widely investigated as a steroid hormone-sensitive cancer. Following this hypothesis, many epidemiological studies have investigated the relationship between estrogens and melanoma. No evidence to date has supported this association due to the great complexity of genetic, external and environmental factors underlying the development of this cancer. Molecular mechanisms through which estrogen and their receptor exert a role in melanoma genesis are still under investigation with new studies increasingly focusing on the discovery of new molecular targets for therapeutic treatments.

Phytoestrogen exposure alters endometrial stromal cells and interferes with decidualization signaling

OBJECTIVE

To investigate whether phytoestrogens (genistein and daidzein) alter in vitro decidualization of human endometrial stromal cells (ESCs).

DESIGN

Isolated primary ESCs were exposed to phytoestrogens and decidualized in vitro.

SETTING

Academic fertility center.

PATIENT(S)

Twenty fertile oocyte donors attending the IVI Valencia clinic.

INTERVENTION(S)

Treatment of ESC with phytoestrogens at 0, 10, 20, 50, and 100 μM.

MAIN OUTCOME MEASURE(S)

The ESC proliferation was analyzed by MTS assay. In vitro decidualization was induced in the presence of phytoestrogens by medroxyprogesterone acetate/cyclic adenosine 3':5' monophosphate and evaluated by prolactin (PRL) ELISA and F-actin immunostaining. The Ki67 proliferative marker was analyzed by immunofluorescence. The ESC apoptosis was assessed by annexin V/propidium iodide detection using flow cytometry. Estrogen (ERβ) and P receptor (PR) localization were evaluated by immunofluorescence.

RESULT(S)

The ESC exposed to 0, 19, 20, 50, and 100 μM of genistein, daidzein, and genistein + daidzein showed a dose-dependent proliferation decrease. After 48-96 hours of culture, this reduction was significant in the presence of 50 μM of phytoestrogens versus 10 μM untreated ESC. The ESC decidualized in the presence of phytoestrogens did not rearrange their cytoskeletons and showed a significant decrease in PRL secretion compared with untreated decidualized ESCs (dESCs). However, phytoestrogens did not alter proliferative status or the percentage of viable/apoptotic cells in dESC compared with untreated dESC. During decidualization, phytoestrogens induced the same nuclear translocation of ERβ and PR as the control dESC.

CONCLUSION(S)

This study reveals that high doses of phytoestrogens could affect the in vitro decidualization process.

MicroRNAs in porcine uterus and serum are affected by zearalenone and represent a new target for mycotoxin biomarker discovery

The mycotoxin zearalenone (ZEN) poses a risk to animal health because of its estrogenic effects. Diagnosis of ZEN-induced disorders remains challenging due to the lack of appropriate biomarkers. In this regard, circulating microRNAs (small non-coding RNAs) have remarkable potential, as they can serve as indicators for pathological processes in tissue. Thus, we combined untargeted and targeted transcriptomics approaches to investigate the effects of ZEN on the microRNA expression in porcine uterus, jejunum and serum, respectively. To this end, twenty-four piglets received uncontaminated feed (Control) or feed containing 0.17 mg/kg ZEN (ZEN low), 1.46 mg/kg ZEN (ZEN medium) and 4.58 mg/kg ZEN (ZEN high). After 28 days, the microRNA expression in the jejunum remained unaffected, while significant changes in the uterine microRNA profile were observed. Importantly, 14 microRNAs were commonly and dose-dependently affected in both the ZEN medium and ZEN high group, including microRNAs from the miR-503 cluster (i.e. ssc-miR-424-5p, ssc-miR-450a, ssc-miR-450b-5p, ssc-miR-450c-5p, ssc-miR-503 and ssc-miR-542-3p). Predicted target genes for those microRNAs are associated with regulation of gene expression and signal transduction (e.g. cell cycle). Although the effects in serum were less pronounced, receiver operating characteristic analysis revealed that several microRNA ratios were able to discriminate properly between non-exposed and ZEN-exposed pigs (e.g. ssc-miR-135a-5p/ssc-miR-432-5p, ssc-miR-542-3p/ssc-miR-493-3p). This work sheds new light on the molecular mechanisms of ZEN, and fosters biomarker discovery.

Estradiol receptor profile and estrogen responsiveness in laryngeal cancer and clinical outcomes

There is growing evidence that laryngeal cancers are responsive to sex hormones, specifically 17β-estradiol (E₂), despite controversy regarding the presence and characterization of E₂ receptors (ER). Determination of sex hormone responsiveness impacts the prognosis of laryngeal cancer patients and the treatment modalities implemented by their clinicians. Discovery of membrane-associated steroid hormone receptors and rapid membrane signaling opened the possibility that cancers previously labeled 'non-hormone dependent' and 'ER negative' might in fact be susceptible to the effects of E₂ via these membrane receptors. ERα66 and ERβ, the classical nuclear receptors, are present in the membranes of different cancer cells via a mechanism referred to as trafficking. Novel splice variants of these traditional receptors, a key example being ERα36, have also been found in the caveolae of cancer cells. Previous work demonstrated that ERα36 has a role in the tumorigenesis of laryngeal cancer, enhancing both proliferation and the anti-apoptotic effect of E₂ against chemotherapeutics. The present study showed that expression of different membrane ERs in laryngeal cancer is not uniform, which may result in differential and even antagonistic responses to E₂. E₂ had protective or deleterious effects in different cancer cell lines, stimulating proliferation and conferring anti-apoptotic potential to the cancer cells according to their receptor profile. These findings stress the importance of establishing the molecular and clinical characterization of the specific laryngeal tumor in order to tailor treatment accordingly, thus optimizing care while reducing adverse effects for individual patients.

Sex hormone receptor expression and survival in esophageal adenocarcinoma: a prospective cohort study

INTRODUCTION

A striking epidemiological feature of esophageal adenocarcinoma (EAC) is its strong, unexplained male predominance but few studies have evaluated the prevalence of sex hormone receptor expression in EAC.

RESULTS

A low proportion of EAC tumors stained positive for ERα (4%) and AR (3%) while approximately one third stained positive for ERβ (31%). After a mean follow-up of 3 years (max 9 years), no significant associations were seen for ERα, ERβ or AR expression and EAC recurrence or survival. A non-significant reduction in mortality was observed for positive ERβ tumor expression, when restricting to patients with gastro-esophageal junctional (GEJ) cancer (HR 0.58, 95% CI 0.33, 1.03, p = 0.06).

MATERIALS AND METHODS

We identified all EAC patients who underwent neo-adjuvant chemotherapy prior to surgical resection between 2004-2012 in the Northern Ireland Cancer Centre. Immunohistochemical expression of ERα, ERβ and AR was scored on triplicate cores to generate H-scores. Cox proportional hazards regression was used to evaluate the association between sex hormone receptor expression and overall, cancer-specific and recurrence-free survival.

CONCLUSION

We found little evidence of ERα or AR expression in EAC. A moderate proportion expressed ERβ and there was suggestive evidence that its expression was associated with improved survival in GEJ cancer patients.

Potential Mechanisms of Age Acceleration Caused by Estrogen Deprivation: Do Endocrine Therapies Carry the Same Risks?

Longer duration of endocrine therapy decreases breast cancer recurrence and mortality, but these benefits need to be weighed against potential risks to overall health. Notable side effects of endocrine therapy include cataracts, uterine cancer, thromboembolic events, osteoporosis and fracture risk, chronic musculoskeletal complaints, as well as vaginal dryness and discharge, and vasomotor symptoms. Estrogen deprivation in healthy women younger than 50 years undergoing bilateral oophorectomy has been shown to accelerate the development of diseases related to aging, including coronary artery disease, cardiac arrhythmias, stroke, dementia, and osteoporosis, raising concern that even less dramatic modulation of estrogen homeostasis may adversely affect health outcomes. Diminished available estrogen at the cellular and molecular level may facilitate mechanisms that underlie the aging process, often termed the hallmarks of aging. In this review, we describe estrogen's role in normal physiology across tissues, review the effects of estrogen deprivation on health outcomes in the setting of both surgical and natural menopause, and examine the hallmarks of aging with attention to the effects of estrogen and estrogen blockade on each molecular mechanism underlying the aging process.

Deciphering sex differences in the immune system and depression

Certain mood disorders and autoimmune diseases are predominately female diseases but we do not know why. Here, we explore the relationship between depression and the immune system from a sex-based perspective. This review characterizes sex differences in the immune system in health and disease. We explore the contribution of gonadal and stress hormones to immune function at the cellular and molecular level in the brain and body. We propose hormonal and genetic sex specific immune mechanisms that may contribute to the etiology of mood disorders.

Dehydrodiconiferyl Alcohol Inhibits Osteoclast Differentiation and Ovariectomy-Induced Bone Loss through Acting as an Estrogen Receptor Agonist

Estrogen deficiency after menopause increases bone loss by activating RANKL-induced osteoclast differentiation. Dehydrodiconiferyl alcohol (DHCA), a lignan originally isolated from Cucurbita moschata, has been thought to be a phytoestrogen based on its structure. In this study, we tested whether DHCA could affect RANKL-induced osteoclastogenesis in vitro and ovariectomy-induced bone loss in vivo. In RAW264.7 cells, DHCA inhibited RANKL-induced differentiation of osteoclasts. Consistently, expression of the six osteoclastogenic genes induced by RANKL was down-regulated. DHCA was also shown to suppress the NF-κB and p38 MAPK signaling pathways by activating AMPK. Data from transient transfection assays suggested that DHCA might activate the estrogen receptor signaling pathway. Effects of DHCA on RANKL-induced osteoclastogenesis were reduced when cells were treated with specific siRNA to ERα, but not to ERβ. Interestingly, DHCA was predicted from molecular docking simulation to bind to both ERα and ERβ. Indeed, data from an estrogen receptor competition assay revealed that DHCA acted as an agonist on both estrogen receptors. In the ovariectomized (Ovx) mouse model, DHCA prevented Ovx-induced bone loss by inhibiting osteoclastogenesis. Taken together, our results suggest that DHCA may be developed as an efficient therapeutic for osteoporosis by regulating osteoclastogenesis through its estrogenic effects.

Estrogenic Mechanisms and Cardiac Responses Following Early Life Exposure to Bisphenol A (BPA) and Its Metabolite 4-Methyl-2,4-bis( p-hydroxyphenyl)pent-1-ene (MBP) in Zebrafish

Environmental exposure to Bisphenol A (BPA) has been associated with a range of adverse health effects, including on the cardiovascular system in humans. Lack of agreement on its mechanism(s) of action likely stem from comparisons between in vivo and in vitro test systems and potential multiple effects pathways. In rodents, in vivo, metabolic activation of BPA produces 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP), which is reported to be up to 1000 times more potent as an estrogen than BPA. We investigated the estrogenic effects and estrogen receptor signaling pathway(s) of BPA and MBP following early life exposure using a transgenic, estrogen responsive (ERE-TG) zebrafish and a targeted morpholino approach to knockdown the three fish estrogen receptor (ER) subtypes. The functional consequences of BPA exposure on the cardiovascular system of zebrafish larvae were also examined. The heart atrioventricular valves and the bulbus arteriosus were primary target tissues for both BPA and MBP in the ERE-TG zebrafish, and MBP was approximately 1000-fold more potent than BPA as an estrogen in these tissues. Estrogen receptor knockdown with morpholinos indicated that the estrogenic responses in the heart for both BPA and MBP were mediated via an estrogen receptor 1 (esr1) dependent pathway. At the highest BPA concentration tested (2500 μg/L), alterations in the atrial:ventricular beat ratio indicated a functional impact on the heart of 5 days post fertilization (dpf) larvae, and there was also a significantly reduced heart rate in these larvae at 14 dpf. Our findings indicate that some of the reported adverse effects on heart function associated with BPA exposure (in mammals) may act through an estrogenic mechanism, but that fish are unlikely to be susceptible to adverse effects on heart development for environmentally relevant exposures.

Supplemental flaxseed modulates ovarian functions of weanling gilts via the action of selected fatty acids

The aim of this study was to examine the influence of dietary flaxseed on the endocrine and ovarian functions of weanling gilts challenged with E. coli and Coronavirus infections treated with dietary probiotic cheeses and to understand the possible mechanisms of its effects on ovarian function. Probiotics were used as a natural substitution for antibiotics and 10% dietary flaxseed is an effective prebiotic which supports the action of probiotics and has other beneficial effects on the organism. Probiotics with or without flaxseed were fed to weanling gilts starting 10 days before and lasting up until 14 days after weaning. The ovaries were measured and histologically analysed. The blood samples for the levels of steroid hormones and insulin-like growth factor I (IGF-I) were assessed using immunoassays and the levels of fatty acids were assessed using gas chromatography. All samples were collected on the day of weaning and 14 days after weaning. On the day of weaning, increased levels of linoleic acid and IGF-I was associated with higher body weight. The steroid hormones were not affected by the diet. The conversion of alpha-linolenic acid (ALA) to timodonic (EPA) and cervonic (DHA) acids were lower compared to controls, and together with high levels of myristic, palmitic and palmitoleic acids was associated with the higher proliferation and lower apoptosis in the primordial, primary and secondary follicles; although the inhibition of the cell cycle was observed in relation to the low level of eicosadienoic acid. The high levels of ALA, EPA and DHA and the low levels of myristic, palmitic and palmitoleic acids may have been the effect of flaxseed feeding 14 days post-weaning and may have had a reverse effect on the proliferation and apoptosis of ovarian follicles. These data suggest that flaxseed may suppress the follicle development in weanlings via the stimulation of apoptosis and the inhibition of proliferation via the modulation of the metabolism of selected fatty acids.

Towards optimization of estrogen receptor modulation in medicine

Women now spend more than one-third of their lives in the postmenopausal years, and the decline of endogenous estrogen production during menopause is accompanied by a series of functional disorders that affect the quality of life. These symptoms could be alleviated or even totally suppressed by menopausal hormone therapy (MHT), initially based on natural estrogens extracted from the urine of pregnant mares (mainly in the USA, using the oral route) and later from the synthesis of the natural estrogen, 17β-estradiol (mainly in Europe, in particular using the transdermal route). Estrogen receptor (ER) α is the main receptor mediating the physiological effects of estrogens. ERα belongs to the nuclear receptor superfamily and activates gene transcription in a time and tissue-specific manner through two distinct activation functions (AF), AF1 and AF2. In addition to these classical genomic actions, ERα also mediates membrane initiated signaling enabling rapid actions of estrogen, potentially along or in interaction with other receptors. Here, we provide a brief historical overview of MHT, and we then highlight recent advances in the characterization of new treatments based on the association of estrogens with selective estrogen receptor modulators (SERMs) or on the modulation of nuclear or membrane ERα.

Perfluoroalkylated substances (PFAS) affect neither estrogen and androgen receptor activity nor steroidogenesis in human cells in vitro

The perfluoroalkylated substances (PFAS) perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are used for the fabrication of water- and dirt-repellent surfaces. The use of PFOS and PFOA was restricted due to their reprotoxic properties and their environmental persistence. Therefore, industry switches to alternative PFAS, however, in contrast to PFOA and PFOS only few toxicological data are available for their substitutes. The molecular mechanism(s) underlying reproductive toxicity of PFOA and PFOS are largely unknown. Here, the endocrine properties of PFOA, PFOS, and of six substitutes including perfluorohexanesulfonic acid (PFHxS), perfluorobutanesulfonic acid (PFBS), perfluorohexanoic acid (PFHxA), perfluorobutanoic acid (PFBA), ammonium perfluoro(2-methyl-3-oxahexanoate) (PMOH), and 3H-perfluoro-3-[(3-methoxypropoxy) propanoic acid] (PMPP) were examined in vitro by using human cell lines such as MCF-7, H295R, LNCaP and MDA-kb2. PFOA, PFOS and PMOH enhanced 17β-estradiol-stimulated estrogen receptor β activity, and PFOS, PMOH, PFHxA and PFBA enhanced dihydrotestosterone-stimulated androgen receptor activity. In the H295R steroidogenesis assay, PFOA and PFOS slightly enhanced estrone secretion, and progesterone secretion was marginally increased by PFOA. All these effects were only observed at concentrations above 10 μM, and none of the PFAS displayed any effect on any of the molecular endocrine endpoints at concentrations of 10 μM or below. Thus, as the blood serum concentrations of the different PFAS in the general Western population are in the range of 10 nM or below, the results suggest that PFAS might not exert endocrine effects in humans at exposure-relevant concentrations according to the molecular endpoints examined in this study.

Gender differences in acute coronary syndromes: focus on the women with ACS without an obstructing culprit lesion

INTRODUCTION

The etiologies of acute coronary syndromes (ACS) in women expand beyond the traditional paradigm of obstructive epicardial atherosclerotic disease and plaque rupture. Fundamental differences in pathobiology and presentation can partially explain the gender disparity in ACS diagnosis and management, but there is also much we do not know about the spectrum of coronary artery disease in women. Areas covered: This review seeks to explain some key differences between men and women in terms of risk factors, pathophysiology, and clinical presentations, as well as identify areas where more data are needed, focusing on women presenting with ACS but without a culprit lesion to explain their presentation. Literature search was undertaken with PubMed and Google Scholar. Expert commentary: Women with acute coronary syndromes but without plaque rupture or obstructive epicardial atherosclerosis can be difficult to diagnose and manage. Improving care in this underdiagnosed and undertreated population will require early identification of at risk patients, development of better diagnostic strategies, and standardized implementation of guideline-based therapies.

Sex hormone allergy: clinical aspects, causes and therapeutic strategies - Update and secondary publication

Sex hormone allergy as a clinical syndrome has been known for almost a century. Due to the diversity of clinical presentation regarding symptoms and disease patterns, the optimal patient care represents an enormous interdisciplinary challenge. Frequently, hypersensitivity reactions affect more than one sex hormone and double positive tests for estrogen and progesterone have been described. Since the menstrual cycle dependent symptoms range from skin afflictions, gynecological problems to non-specific reactions, different pathophysiological mechanisms seem likely.

Various desensitization protocols are described as causal treatment options, but are rarely applied in clinical routine. Consequently, major research efforts with a quick translation of therapeutic interventions into clinical practice will be crucial to help affected patients in the future.

Dual expression of immunoreactive estrogen receptor β and p53 is a potential predictor of regional lymph node metastasis and postoperative recurrence in endometrial endometrioid carcinoma

Although histological grade and muscular invasion are related to the malignant behaviors of endometrial endometrioid carcinoma, lymphatic and/or distant metastases are unexpectedly encountered, even in patients in the low-risk group. To re-evaluate additional reliable parameters to predict the risk of progression, we examined the immunohistochemical expression profiles of p53 and estrogen receptor (ER) β proteins. Patients with endometrial endometrioid carcinoma who underwent surgical treatment at our hospital (n = 154) were recruited to this study, and the significance of the relationships between the incidence of regional lymph node metastasis and/or postoperative recurrence and clinical or experimental parameters was evaluated. By multivariate analysis, we found that histological grades, detection of immunoreactive p53 (positive rates more than 10%, p53-stained), and high expression of ERβ (high-ERβ) were independently associated with metastasis and/or recurrence. Among these parameters, the sensitivity and negative predictive values of high-ERβ were very high (up to 100%). In the population with high-ERβ, the positive rates of metastasis and/or recurrence were 61.1% in the p53-stained group and 21.9% in the p53-non-stained (negative) group. Furthermore, the positive rate in the group showing myometrial invasion of more than 1/2 and showing both p53-stained and high-ERβ was 80%. The disease-free survival of patients who were double-positive for p53-stained and high-ERβ was significantly shorter than that in other patients. In summary, our findings showed that increases in ERβ and p53 immunoreactivity were significantly correlated with the incidence of metastasis and/or recurrence in endometrial endometrioid carcinoma, suggesting that double-positivity for p53-stained and high-ERβ may provide a promising clinical indicator to predict the risk of progression.

Effects of Female Sex Steroids Administration on Pathophysiologic Mechanisms in Traumatic Brain Injury

Secondary brain damage following initial brain damage in traumatic brain injury (TBI) is a major cause of adverse outcomes. There are many gaps in TBI research and a lack of therapy to limit debilitating outcomes in TBI or enhance the neurogenesis, despite pre-clinical and clinical research performed in TBI. Females show harmful outcomes against brain damage including TBI less than males, independent of different TBI occurrence. A significant reduction in secondary brain damage and improvement in neurologic outcome post-TBI has been reported following the use of progesterone and estrogen in many experimental studies. Although useful features of sex steroids including progesterone have been identified in TBI clinical trials I and II, clinical trials III have been unsuccessful. This review article focuses on evidence of secondary injury mechanisms and neuroprotective effects of estrogen and progesterone in TBI. Understanding these mechanisms may enable researchers to achieve greater success in TBI clinical studies. It seems that the design of clinical studies should be revised due to translation loss of animal studies to clinical studies. The heterogeneous and complex nature of TBI, the endogenous levels of sex hormones at the time of taking these hormones, the therapeutic window of the drug, the dosage of the drug, the selection of appropriate targets in evaluation, the determination of responsive population, gender and age based on animal studies should be considered in the design of TBI human studies in future.

Estrogens as neuroprotectants: Estrogenic actions in the context of cognitive aging and brain injury

There is ample empirical evidence to support the notion that the biological impacts of estrogen extend beyond the gonads to other bodily systems, including the brain and behavior. Converging preclinical findings have indicated a neuroprotective role for estrogen in a variety of experimental models of cognitive function and brain insult. However, the surprising null or even detrimental findings of several large clinical trials evaluating the ability of estrogen-containing hormone treatments to protect against age-related brain changes and insults, including cognitive aging and brain injury, led to hesitation by both clinicians and patients in the use of exogenous estrogenic treatments for nervous system outcomes. That estrogen-containing therapies are used by tens of millions of women for a variety of health-related applications across the lifespan has made identifying conditions under which benefits with estrogen treatment will be realized an important public health issue. Here we provide a summary of the biological actions of estrogen and estrogen-containing formulations in the context of aging, cognition, stroke, and traumatic brain injury. We have devoted special attention to highlighting the notion that estrogen appears to be a conditional neuroprotectant whose efficacy is modulated by several interacting factors. By developing criteria standards for desired beneficial peripheral and neuroprotective outcomes among unique patient populations, we can optimize estrogen treatments for attenuating the consequences of, and perhaps even preventing, cognitive aging and brain injury.

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.

From Pregnancy to Preeclampsia: A Key Role for Estrogens

Preeclampsia (PE) results in placental dysfunction and is one of the primary causes of maternal and fetal mortality and morbidity. During pregnancy, estrogen is produced primarily in the placenta by conversion of androgen precursors originating from maternal and fetal adrenal glands. These processes lead to increased plasma estrogen concentrations compared with levels in nonpregnant women. Aberrant production of estrogens could play a key role in PE symptoms because they are exclusively produced by the placenta and they promote angiogenesis and vasodilation. Previous assessments of estrogen synthesis during PE yielded conflicting results, possibly because of the lack of specificity of the assays. However, with the introduction of reliable analytical protocols using liquid chromatography/mass spectrometry or gas chromatography/mass spectrometry, more recent studies suggest a marked decrease in estradiol levels in PE. The aim of this review is to summarize current knowledge of estrogen synthesis, regulation in the placenta, and biological effects during pregnancy and PE. Moreover, this review highlights the links among the occurrence of PE, estrogen biosynthesis, angiogenic factors, and cardiovascular risk factors. A close link between estrogen dysregulation and PE occurrence might validate estrogen levels as a biomarker but could also reveal a potential approach for prevention or cure of PE.

17β-Oestradiol promotes differentiation of human embryonic stem cells into dopamine neurons via cross-talk between insulin-like growth factors-1 and oestrogen receptor β

Human embryonic stem cells (hESCs) can self‐renew and differentiate into all cell lineages. E2 is known to exhibit positive effects on embryo development. Although the importance of E2 in many physiological processes has been reported, to date few researchers have investigated the effects of E2 on hESCs differentiation. We studied the effects of E2 on dopamine (DA) neuron induction of hESCs and its related signalling pathways using the three‐stage protocol. In our study, 0.1 μM E2 were applied to hESCs‐derived human embryoid bodies (hEBs) and effects of E2 on neural cells differentiation were investigated. Protein and mRNA level assay indicated that E2 up‐regulated the expression of insulin‐like growth factors (IGF)‐1, ectoderm, neural precursor cells (NPC) and DA neuron markers, respectively. The population of hESC‐derived NPCs and DA neurons was increased to 92% and 93% to that of DMSO group, respectively. Furthermore, yield of DA neuron‐secreted tyrosine hydroxylase (TH) and dopamine was also increased. E2‐caused promotion was relieved in single inhibitor (ICI or JB1) group partly, and E2 effects were repressed more stronger in inhibitors combination (ICI plus JB1) group than in single inhibitor group at hEBs, hNPCs and hDA neurons stages. Owing to oestrogen receptors regulate multiple brain functions, when single or two inhibitors were used to treat neural differentiation stage, we found that oestrogen receptor (ER)β but not ERα is strongly repressed at the hNPCs and hDA neurons stage. These findings, for the first time, demonstrate the molecular cascade and related cell biology events involved in E2‐improved hNPC and hDA neuron differentiation through cross‐talk between IGF‐1 and ERβ in vitro.

Comprehensive assessment of estrogen receptor beta antibodies in cancer cell line models and tissue reveals critical limitations in reagent specificity

Estrogen Receptor-β (ERβ) has been implicated in many cancers. In prostate and breast cancer its function is controversial, but genetic studies implicate a role in cancer progression. Much of the confusion around ERβ stems from antibodies that are inadequately validated, yet have become standard tools for deciphering its role. Using an ERβ-inducible cell system we assessed commonly utilized ERβ antibodies and show that one of the most commonly used antibodies, NCL-ER-BETA, is non-specific for ERβ. Other antibodies have limited ERβ specificity or are only specific in one experimental modality. ERβ is commonly studied in MCF-7 (breast) and LNCaP (prostate) cancer cell lines, but we found no ERβ expression in either, using validated antibodies and independent mass spectrometry-based approaches. Our findings question conclusions made about ERβ using the NCL-ER-BETA antibody, or LNCaP and MCF-7 cell lines. We describe robust reagents, which detect ERβ across multiple experimental approaches and in clinical samples.

ALZHEIMER'S DISEASE - ESTROGENS AND SELECTIVE ESTROGEN RECEPTOR MODULATORS, FRIENDS OR FOES?

Alzheimer's disease(AD) is the leading cause of dementia and is characterized by the presence of extensive plaque deposition and neurofibrillary pathology. The aim of the present study was to make an update regarding the influence of estrogens and SERMs on inflammation and on the resolution of inflammation, respectively, focusing on these most important features implicated in the pathophysiology of AD. Several hypothesised mechanisms of action of estrogens and SERM are exposed and also some relevant clinical studies on this subject are analysed. The analyzed studies have a high heterogeneity of preparations used, of administration routes, of the female population included and of the periods of time from the appearance/induction of menopause to the therapeutic intervention and also of follow-up periods of patients and of the means of evaluating their cognitive decline. One can say that all the ways of pharmacological influence on the membrane or intracellular signalling system associated to estrogens that may have clinical importance in the prevention and possibly in the treatment of AD have not been exhausted. Estrogens with selective ERα or G protein-coupled estrogen receptors (GPER1 or GqMER) effects could be used to influence the resolution of inflammation process, with positive effects on AD evolution.

Lack of estrogen receptor α in astrocytes of progranulin-deficient mice

Progranulin (PGRN) is a multifunctional growth factor with functions in neuroprotection, anti-inflammation, and neural progenitor cell proliferation. These functions largely overlap with the actions of estrogen in the brain. Indeed, we have previously shown that PGRN mediates the functions of estrogen, such as masculinizing the rodent brain and promoting adult neurogenesis. To evaluate the underlying mechanism of PGRN in mediating the actions of estrogen, the localization of estrogen receptor α (ERα) in the brains of wild-type (WT) and PGRN-deficient (KO) mice was investigated. First, double-labeling immunofluorescence was performed for ERα with neuronal nuclei (NeuN), ionized calcium-binding adaptor molecule 1 (Iba1), and glial fibrillary acidic protein (GFAP), as markers for neurons, microglia, and astrocytes, respectively, in female mice in diestrous and estrous stages. ERα-immunoreactive (IR) cells were widespread and co-localized with NeuN in brain sections analyzed (bregma –1.06 to –3.16 mm) of both WT and KO mice. In contrast, expression of ERα was not observed in Iba1-IR cells from both genotypes. Interestingly, although ERα was co-localized with GFAP in WT mice, virtually no ERα expression was discernible in GFAP-IR cells in KO mice. Next, the brains of ovariectomized adult female, adult male, and immature female mice were subjected to immunostaining for ERα and GFAP. Again, co-localization of ERα with GFAP was observed in WT mice, whereas this co-localization was not detected in KO mice. These results suggest that PGRN plays a crucial role in the expression of ERα in astrocytes regardless of the estrous cycle stage, sex, and maturity.

Mixture Effects of Estrogenic Pesticides at the Human Estrogen Receptor α and β

Consumers of fruits and vegetables are frequently exposed to small amounts of hormonally active pesticides, some of them sharing a common mode of action such as the activation of the human estrogen receptor α (hERα) or β (hERβ). Therefore, it is of particular importance to evaluate risks emanating from chemical mixtures, in which the individual pesticides are present at human-relevant concentrations, below their corresponding maximum residue levels. Binary and ternary iso-effective mixtures of estrogenic pesticides at effect concentrations eliciting a 1 or 10% effect in the presence or absence of 17β-estradiol were tested experimentally at the hERα in the yeast-based estrogen screen (YES) assay as well as in the human U2-OS cell-based ERα chemical-activated luciferase gene expression (ERα CALUX) assay and at the hERβ in the ERβ CALUX assay. The outcome was then compared to predictions calculated by means of concentration addition. In most cases, additive effects were observed with the tested combinations in all three test systems, an observation that supports the need to expand the risk assessment of pesticides and consider cumulative risk assessment. An additional testing of mixture effects at the hERβ showed that most test substances being active at the hERα could also elicit additive effects at the hERβ, but the hERβ was less sensitive. In conclusion, effects of the same ligands at the hERα and the hERβ could influence the estrogenic outcome under physiological conditions.

Estrogen Receptor β in Melanoma: From Molecular Insights to Potential Clinical Utility

Cutaneous melanoma is an aggressive tumor; its incidence has been reported to increase fast in the past decades. Melanoma is a heterogeneous tumor, with most patients harboring mutations in the BRAF or NRAS oncogenes, leading to the overactivation of the MAPK/ERK and PI3K/Akt pathways. The current therapeutic approaches are based on therapies targeting mutated BRAF and the downstream pathway, and on monoclonal antibodies against the immune checkpoint blockade. However, treatment resistance and side effects are common events of these therapeutic strategies. Increasing evidence supports that melanoma is a hormone-related cancer. Melanoma incidence is higher in males than in females, and females have a significant survival advantage over men. Estrogens exert their effects through estrogen receptors (ERα and ERβ) that affect cancer growth in an opposite way: ERα is associated with a proliferative action and ERβ with an anticancer effect. ERβ is the predominant ER in melanoma, and its expression decreases in melanoma progression, supporting its role as a tumor suppressor. Thus, ERβ is now considered as an effective molecular target for melanoma treatment. 17β-estradiol was reported to inhibit melanoma cells proliferation; however, clinical trials did not provide the expected survival benefits. In vitro studies demonstrate that ERβ ligands inhibit the proliferation of melanoma cells harboring the NRAS (but not the BRAF) mutation, suggesting that ERβ activation might impair melanoma development through the inhibition of the PI3K/Akt pathway. These data suggest that ERβ agonists might be considered as an effective treatment strategy, in combination with MAPK inhibitors, for NRAS mutant melanomas. In an era of personalized medicine, pretreatment evaluation of the expression of ER isoforms together with the concurrent oncogenic mutations should be considered before selecting the most appropriate therapeutic intervention. Natural compounds that specifically bind to ERβ have been identified. These phytoestrogens decrease the proliferation of melanoma cells. Importantly, these effects are unrelated to the oncogenic mutations of melanomas, suggesting that, in addition to their ERβ activating function, these compounds might impair melanoma development through additional mechanisms. A better identification of the role of ERβ in melanoma development will help increase the therapeutic options for this aggressive pathology.

Women-specific factors to consider in risk, diagnosis and treatment of cardiovascular disease

In the era of individualized medicine, gaps in knowledge remain about sex-specific risk factors, diagnostic and treatment options that might reduce mortality from cardiovascular disease (CVD) and improve outcomes for both women and men. In this review, contributions of biological mechanisms involving the sex chromosomes and the sex hormones on the cardiovascular system will be discussed in relationship to the female-specific risk factors for CVD: hypertensive disorders of pregnancy, menopause and use of hormonal therapies for contraception and menopausal symptoms. Additionally, sex-specific factors to consider in the differential diagnosis and treatment of four prevalent CVDs (hypertension, stroke, coronary artery disease and congestive heart failure) will be reviewed with emphasis on areas where additional research is needed.

Membrane lipid rafts and estrogenic signalling: a functional role in the modulation of cell homeostasis

It has become widely accepted that along with their ability to directly regulate gene expression, estrogens also influence cell signalling and cell function via rapid membrane-initiated events. Many of these signalling processes are dependent on estrogen receptors (ER) localized to the plasma membrane. However, the mechanisms by which ER are able to trigger cell signalling when targeted to the membrane surface have to be determined yet. Lipid rafts seem to be essential for the plasma membrane localization of ER and play a critical role in their membrane-initiated effects. In this review, we briefly recapitulate the localization and function of ER in different cell types and mostly discuss the possible role of lipid rafts in this context. Further studies in this field may disclose new promising therapeutic avenues by the disruption of lipid rafts in those diseases in which membrane ER activation has been demonstrated to play a pathogenetic role.

Phosphorylation Alters Oestrogen Receptor β-Mediated Transcription in Neurones

Nuclear steroid hormone receptors are ubiquitously expressed transcription factors whose activity can be altered by post-translational modifications, such as phosphorylation. The consequences of post-translational modifications have been described for several members of the nuclear steroid hormone receptor superfamily; however, little is known about the effects of oestrogen receptor (ER)β phosphorylation in the brain. Moreover, to our knowledge, the presence of phosphorylated ERβ has not been detected in the brain of any species to date. Oestrogen receptor β is highly expressed in several regions of the brain and in vitro studies have demonstrated that it can be phosphorylated at two serine residues (S87 and S105) in the N-terminal AF-1 region. The present study aimed to determine whether phosphorylated ERβ is detectable in the hippocampus of aged female rats, as well as the functional consequences of ERβ S87 and S105 phosphorylation on transcriptional activity in neuronal cells. First, we used a novel PhosTag(™) approach to detect phosphorylated forms of ERβ in the dorsal hippocampus of aged female rats. The data obtained demonstrated abundant forms of phosphorylated ERβ in the dorsal hippocampus, suggesting that this post-translational modification might be an important regulator of ERβ function. To assess the functional consequences of ERβ phosphorylation in neuronal cells, we created phospho-mimetic (S87E, S105E) and phospho-null (S87A, S105A) ERβ receptors that were transiently transfected in a hippocampal-derived cell line. Collectively, our results showed that phosphorylation of S87 and S105 altered both ligand-independent and ligand-dependent ERβ transcriptional regulation. Overall, these data demonstrate that phosphorylated forms of ERβ are present in the brain of aged female rats and that phosphorylation of ERβ could differentially alter ERβ-mediated gene expression.

SNP analysis reveals estrogen receptor 1 (<i>ESR1</i>) gene variants associated with laying traits in quails

Abstract. In this study, the estrogen receptor 1 (ESR1) gene was studied as a candidate gene for laying traits of two quail populations (the yellow-feather quail and chestnut-feather quail). Five pairs of primers were designed to detect single-nucleotide polymorphisms (SNPs) of exon 1, 2, 4, 8 and intron 1 of the ESR1 gene by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) and sequencing methods. Only the products amplified from exon 8 displayed polymorphism. The results showed one novel variation: a variation in exon 8 of ESR1 gene (g.91C > T, KC977991 and KC977992). It was associated with some laying traits in two quail populations including egg weight, the age of first egg and egg number at 20 weeks. And the CC genotype was associated with superior egg number at 20 weeks. Therefore, we speculated that the variation in exon 8 of ESR1 gene may have an effect on laying traits in the abovementioned quail populations.