ERα Gene Research Articles

The 3'UTR 3179 T/C Polymorphism of the ERα Gene Influences Bone Resorption's Impact on Blood Pb in Pregnancy and Postpartum

The 3'UTR 3179 T/C Polymorphism of the ERα Gene Influences Bone Resorption's Impact on Blood Pb in Pregnancy and Postpartum

The Expression of Adipogenic Marker Is Significantly Increased in Estrogen-Treated Lipedema Adipocytes Differentiated from Adipose Stem Cells In Vitro.

Lipedema is a chronic, idiopathic, and painful disease characterized by an excess of adipose tissue in the extremities. The goal of this study is to characterize the gene expression of estrogen receptors (ERα and ERβ), G protein-coupled estrogen receptor (GPER), and ER-metabolizing enzymes: hydroxysteroid 17-beta dehydrogenase (HSD17B1, 7, B12), cytochrome P450 (CYP19A1), hormone-sensitive lipase (LIPE), enzyme steroid sulfatase (STS), and estrogen sulfotransferase (SULT1E1), which are markers in Body Mass Index (BMI) and age-matched non-lipedema (healthy) and lipedema ASCs and spheroids. Flow cytometry and cellular proliferation assays, RT-PCR, and Western Blot techniques were used to determine the expression of ERs and estrogen-metabolizing enzymes. In 2D monolayer culture, estrogen increased the proliferation and the expression of the mesenchymal marker, CD73, in hormone-depleted (HD) healthy ASCs compared to lipedema ASCs. The expression of ERβ was significantly increased in HD lipedema ASCs and spheroids compared to corresponding healthy cells. In contrast, ERα and GPER gene expression was significantly decreased in estrogen-treated lipedema spheroids. CYP19A1 and LIPE gene expressions were significantly increased in estrogen-treated healthy ASCs and spheroids, respectively, while estrogen upregulated the expression of PPAR-ϒ2 and ERα in estrogen-treated lipedema-differentiated adipocytes and spheroids. These results indicate that estrogen may play a role in adipose tissue dysregulation in lipedema.

Sex-Specific Regulation of Local Gonadal Hormone Signaling During Pathological Cardiac Remodeling in Spontaneously Hypertensive Rats

Hypertensive heart disease is characterized by cardiac fibrosis in the left ventricle (LV). Angiotensin II (Ang II) promotes cardiac fibrosis through direct actions on cardiac fibroblasts. Gonadal hormones are known to impact cardiac fibrosis either through direct actions on fibroblasts or through modulation of Ang II receptors. We have previously shown that Ang II infusion alters collagen gene expression in a sex-specific manner. The present study seeks to further understand our observed sex difference by investigating the impact of Ang II on gonadal hormone regulation in the left ventricle (LV) and cardiac fibroblasts (CFs) following a fibrogenic stimulus. For whole LV analysis, male and female SHR (15-week-old) were infused with Ang II (400ng/kg/min, s.c.) or vehicle for 2 weeks via an osmotic mini pump (n=8-11 per group per sex). For CF-specific analysis, primary CFs were isolated from adult male and female SHR LV and cultured on CytoSoft cell culture plates (8 kPa stiffness) coated with Type I Collagen. CFs were brought to P1 for expansion and treated with TGFb1 (10ug/uL) or vehicle (PBS + 0.1% BSA) for 48 hours (n=7-8 per group per sex). Col1a1, AT1aR, estrogen receptors α and β (ER-α, ER-β), androgen receptor (AR), 5α-reductase (5α-R), and aromatase gene expression in the left ventricle was assessed via RT-qPCR and data analyzed by Two-Way ANOVA. Ang II infusion significantly increased ER-α gene expression in male, but not female LV (sex x Ang II interaction p=0.0303). ER-β gene expression was also significantly increased in the male LV (p=0.0066), but not females. AR gene expression remained unchanged in the Ang II-infused male LV but was significantly reduced in female LV when compared to control (sex x Ang II interaction p=0.0084). Ang II significantly increased 5α-R gene expression in male (p=0.0024), but not female LV. Aromatase gene expression tended to increase in both male and female Ang II-infused animals when compared to control. Ang II-induced changes in LV gonadal hormone gene expression did not significantly correlate with Col1a1 gene expression. In vitro stimulation of CFs with TGFb1 results in a significant reduction in ER-α (p<0.0001) and AR (p<0.0001) in both males and females. ER-β tended to decrease in males stimulated with TGFb1, but not females, relative to control. Taken together, the opposing findings between LV and CF may indicate cell-specific regulation of gonadal hormone receptors. It may be that upregulation of local estrogen signaling in the remodeling LV in males serves to offset the pathological effects of Ang II stimulation. Future studies will evaluate the consequences of changes in gonadal hormone receptor levels at the cellular and tissue level. NHLBI R01HL153112. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Expression Profiling of Genes Associated with the Pathogenesis of Recurrent Laryngeal Papillomatosis

Recurrent Laryngeal Papillomatosis (RLP) affects the aero-digestive intersection with a predilection for the glottis. It is predominantly a juvenile-onset disease. The main infectious agents are type 6 and 11 low-risk human papillomaviruses. Understanding the genetic changes associated with the pathogenesis of RLP might prove helpful to mark the severity and aggression of the disease and lead to better clinical management. Clinically diagnosed RLP children below the age of 12 years along with a control sample of healthy tissue from age and gender-matched children undergoing tonsillectomy and thyroidectomy were collected. All the samples were processed for total RNA extraction followed by first strand cDNA synthesis. Real-time PCR was done to determine the relative gene expression of EGFR, ER-α, CXCL12, CXCR4, GLUT-1, IGF-1, HIF-1α, VEGF, ERK1/2, PI3K and AKT genes along with GAPDH as gene of reference. An increase in the transcriptional level expression of the genes CXCL12/CXCR4, GLUT-1, EGFR, ER-α, and IGF-I was observed in the cases in comparison to the controls. The expression of HIF-1α, VEGF, PI3K, and AKT genes was not noticeably elevated. The gene expression analysis may open the avenues for possible strategies that can be employed to treat RLP more effectively.

The Estrogenic Effect of Lysiphyllum strychnifolium (Craib) A. Schmitz Leaf Water Extract in MCF-7 Cells

Lysiphyllum strychnifolium (Craib) A. Schmitz (LS) has been widely used as traditional medicine in the northeast region of Thailand to stimulate the production of breast milk. There are no known studies on the estrogenic action of LS on the stimulation of breast milk production. Hence, the present study aimed to investigate the estrogenic effect of LS leaf water extract compared with quercetin, one of the compounds in LS, in human breast cancer cells (MCF-7). The effect of LS leaf water extract and quercetin on cell viability of MCF-7 cells was studied by MTT assay at a concentration range of 0 to 500 µg/mL. The expression of estrogen-dependent genes, the pS2, ERα, and ERβ was also examined by real-time RT-PCR, and the expression of ERα protein was detected by Western blotting. The quercetin content in the LS water extract was 285.67 ± 0.11 µg/g of dry extract. MCF-7 cells treated with LS leaf water extract (20 µg/mL) showed an upregulation of pS2 gene expression similar to that of the treatment with E2 (10−9 M) compared with that of the untreated control. The ERα gene expression was found to be upregulated by quercetin (0.16 µg/mL) and E2 (10−5 M) compared with the untreated control. In addition, quercetin (0.16 µg/mL) and LS extract (0.8, 4, and 20 µg/mL) decreased the phosphorylation of ERα at Ser167. LS extract (20 µg/mL) decreased ERα, but there was no significant effect on the ERα at Ser118 protein expression. This study provided scientific evidence for the potential estrogenic activities of LS leaf water extract. This indicates that ER-dependent pathways in MCF-7 cells served as mediators, facilitating the estrogenic properties of LS and its compounds to function effectively. Since LS induced pS2 gene transcription, it was confirmed that this could affect the transcription of estrogen-responsive genes, causing estrogenic effects. HIGHLIGHTSThis is the first study to demonstrate the estrogenic effect of Lysiphyllum strychnifolium leaf water extract. L. strychnifolium leaf water extract induced pS2 gene transcription, and it was confirmed that this could affect the transcription of estrogen-responsive genes which cause estrogenic effects. The results of this study support the mechanism and scientific evaluation on the use of L. strychnifolium for stimulation of breast milk in folk medicine. GRAPHICAL ABSTRACT

Abstract 6576: Discovery of potent and selective novel small molecule drugs to target estrogen receptor mutants in endocrine-resistant breast cancer

Abstract Introduction: The acquisition of estrogen receptor alpha (ERα) gene (ESR1) mutations is a key driver for the development of resistance to current endocrine therapy in breast cancer. Clinical studies have shown that ESR1 mutations are frequently observed in metastatic ER-positive breast cancer patients and are associated with poor survival. It is well appreciated that activating ESR1 somatic mutations, especially Y537S and D538G, can drive estrogen-independent activities. In addition, these ESR1 mutations diminish the potency of the current standard-of-care agents (tamoxifen and fulvestrant) that bind ERα directly. Therefore, it is an unmet need to develop next-generation antiestrogens that inhibit ERα mutant signaling in breast cancer to improve patient survival. Here, we search for small molecule inhibitors against ERα mutants Y537S and D538G using DNA-encoded chemical library (DEL). Methods: ERα ligand binding domain (LBD) proteins corresponding to wild type (WT), Y537S and D538G mutants were expressed in E. coli and purified by Ni-NTA, anion exchange, and size exclusion chromatography. The ability of these purified proteins to bind ligands was tested in biochemical assays to validate their use in DEL selections. We conducted a DEL affinity selection using our in-house collection of 6 billion small molecule compounds against WT, Y537S and D538G mutants ER LBD proteins in the presence and absence of estradiol. Selection hits that enriched with these targets were resynthesized off-DNA and tested in biochemical and functional studies using CRISPR-Cas9 knock-in Y537S or D538G mutant breast cancer cells. Results: We have successfully purified microgram amounts of ERα LBD for WT, Y537S, and D538G proteins. In our biochemical assay, the SRC3 peptide binds to the WT ERα LBD in the presence of estradiol, whereas Y537S and D538G LBDs bind the SRC3 peptide in the absence of estradiol, consistent with these mutants constitutively binding to SRC3. Our multibillion small molecule collections of DELs can screen and identify several hits in WT and mutant ERα LBDs. To confirm the selection output, we synthesized off-DNA compounds and validated these in biochemical and cell-based studies. Compounds CDD-1274 and CDD-1802 dramatically decrease the WT and mutant ERα protein levels in multiple ER+ breast cancer cells. These compounds greatly reduce protein levels for GREB1, TFF1, c-MYC, E2F1, and survivin in wildtype and mutant breast cancer cells, and they increase levels of cleaved PARP, a marker for apoptosis in wildtype and mutant ER+ breast cancer cells but not in ER-negative breast cancer cells. Conclusion: Our study rapidly identified potent and novel small molecule drugs to target estrogen receptor mutants using our DNA-encoded chemical library platform. Acknowledgments: Funding sources (NIH/NCI R03 CA259664 and CPRIT RP220524 to MP). Citation Format: Anil Kumar Devakrishnan, Chandrashekhar Madasu, Suzanne A.W Fuqua, Martin M. Matzuk, Murugesan Palaniappan. Discovery of potent and selective novel small molecule drugs to target estrogen receptor mutants in endocrine-resistant breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6576.

The Influence of ESR2 Gene Polymorphisms on Susceptibility to Hepatitis B Virus-Related Chronic Hepatitis, Liver Cirrhosis, and Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) represents an estrogen-dependent tumor. The action of estrogen is regulated via estrogen receptor (ER). Polymorphisms in ERα gene, ESR1, are known to be related to HCC susceptibility among people carrying chronic hepatitis B (CHB). But the effect of ERβ on HCC is still largely unclear, and studies about the genetic variability of ESR2 and HCC are rare. For understanding ESR2's effect on HCC, this work tested two polymorphisms in the ESR2 gene promoter as well as the associations with CHB, HCC, and hepatitis B virus (HBV)-related liver cirrhosis (LC) among the Guangxi population. This work enrolled a total of 137 CHB, 136 LC, and 149 HBV-related HCC patients, together with 146 normal subjects. ESR2 polymorphisms rs3020449 and rs2978381 were examined using the SNaPshot genotyping technique. The AG genotype and dominant model of rs3020449 were related to the decreased CHB susceptibility. In both the overall and subgroup analyses, no associations were observed with the remaining models in all patient groups (those with CHB, HBV-related LC, and HCC), but associations were found between the dominant (TC+CC vs TT) and allele models (C vs T) of rs2978381 and increased HBV-related LC and HCC susceptibility, but not CHB. These findings suggest that rs3020449 polymorphism of ESR2 gene makes great contribution to the decreased CHB risk and that rs2978381 significantly contributed to higher risks of HBV-related LC and HCC.

Revealing Propolis Potential Activity on Inhibiting Estrogen Receptor and Heat Shock Protein 90 Overexpressed in Breast Cancer by Bioinformatics Approaches.

Breast cancer is the most commonly diagnosed cancer globally, with the highest incidence of breast cancer occurring in Asian countries including Indonesia. Among the types of breast cancer, the estrogen receptor (ER)-positive subtype which is prominent with estrogen receptor alpha (ERα) and heat shock protein 90 (HSP90) overexpression genes becomes the most prevalent than the others, approximately 75% of all breast cancer cases. ERα and HSP90 play a role in breast cancer activities including breast tumor growth, invasion, and metastasis mechanism. Propolis, a natural bee product, has been explored for its anticancer activity. However, there is lack of studies that evaluated the potential inhibitor from propolis compounds to the ERα and HSP90 proteins. Therefore, this article focuses on examining the correlation between ERα and HSP90's role in breast cancer and investigating the potential of 93 unique propolis compositions in inhibiting these genes in breast cancer using in silico approaches. This study revealed the positive correlation between ERα and HSP90 genes in breast cancer disease development. Furthermore, we also found novel potential bioactive compounds of propolis against breast cancer through binding with ERα and HSP90; they were 3',4',7-trihydroxyisoflavone and baicalein-7-O-β-D glucopyranoside, respectively. Further research on these compounds is needed to elucidate deeper mechanisms and activity in the real biological system to develop new breast cancer drug treatments.

ERα/PR crosstalk is altered in the context of the ERα Y537S mutation and contributes to endocrine therapy-resistant tumor proliferation

The constitutively active ESR1 Y537S mutation is associated with endocrine therapy (ET) resistance and progression of metastatic breast cancer through its effects on estrogen receptor (ERα) gene regulatory functions. However, the complex relationship between ERα and the progesterone receptor (PR), known as ERα/PR crosstalk, has yet to be characterized in the context of the ERα Y537S mutation. Using proximity ligation assays, we identify an increased physical interaction of ERα and PR in the context of the ERα Y537S mutation, including in the nucleus where this interaction may translate to altered gene expression. As such, more than 30 genes were differentially expressed in both patient tumor and cell line data (MCF7 and/or T47D cells) in the context of the ERα Y537S mutation compared to ERα WT. Of these, IRS1 stood out as a gene of interest, and ERα and PR occupancy at chromatin binding sites along IRS1 were uniquely altered in the context of ERα Y537S. Furthermore, siRNA knockdown of IRS1 or treatment with the IRS1 inhibitor NT-157 had a significant anti-proliferative effect in ERα Y537S cell lines, implicating IRS1 as a potential therapeutic target for restoring treatment sensitivity to patients with breast cancers harboring ERα Y537S mutations.

A comprehensive meta-analysis to identify susceptibility genetic variants for precocious puberty.

Currently, several genetic variants in ERα gene (rs2234693 and rs9340799), ERβ gene (rs1256049 and rs4986938), KISS1 gene (rs4889, rs1132506 and rs5780218), LIN28B gene (rs314263, rs314276 and rs314280), and MKRN3 gene (rs2239669) have been repeatedly explored for their contribution to precocious puberty (PP) susceptibility. However, the results remain conflicting rather than conclusive. We here performed a meta-analysis to identify the real susceptibility genetic variants for PP. After screening by inclusion criteria, 20 related studies were finally included in this meta-analysis. The odds ratios and 95% confidence intervals were calculated to assess the strength of association. Sensitive analysis, publication bias, and trial sequential analysis (TSA) were performed to evaluate the stability and reliability of results. Rs2234693, rs9340799, and rs1256049 were significantly associated with PP susceptibility (p<0.0084). Stratified analysis according to ethnicity showed that rs2234693 and rs9340799 were significantly associated with PP susceptibility in Asian and Chinese populations. Stratified analysis according to PP subtype showed that rs2234693 and rs9340799 were significantly associated with idiopathic central PP susceptibility in Asian and Chinese populations (p<0.0084). The results of publication bias, sensitivity analysis, and TSA provided solid evidence for the association between these three variants and PP susceptibility. Rs2234693 and rs9340799 in ERα gene and rs1256049 in ERβ gene may serve as susceptive factors for PP development. The present finding should be confirmed in replication studies and reinforced in functional studies, which will ultimately improve the feasibility of the application of these three PP-susceptible loci in clinical practice.

Cardioprotective effects of calorie restriction against inflammation and apoptosis in ovariectomized obese rats: Role of classical estrogen receptors and SIRT1

AimObesity is a metabolic complication linked with bad eating habits and a sedentary lifestyle, and the heart is one of the target organs damaged by it. Estrogen deficiency during menopause worsens the situation. Calorie restriction (CR) can contribute to reducing cardiovascular disease (CVD) in postmenopausal conditions. Thus, the effects of CR on inflammation and apoptosis in ovariectomized rats' hearts with obesity were studied. MethodFemale Wistar rats were categorized into Sham and OVX (ovariectomized) groups and received a standard diet (SD) or high-fat diet (60%HFD) or calorie restriction (30% CR) for 16 weeks. The real-time PCR method was used to evaluate the inflammatory markers and estrogen receptors gene expression. Western-blot and ELISA methods were respectively used for the measurement of apoptosis and SIRT1 protein expression. ResultsHFD led to the elevation of body weight, IL-6 (interleukin-6) and TNF-α (tumor necrosis factor-α) and reduction of IL-10 (interleukin-10) gene expressions, and also an increment in protein levels of cleaved caspase-3, Bax and Bax/Bcl2 ratio and decrement in Bcl-2 in OVX rats (P < 0.001). Additionally, HFD reduced SIRT1 (sirtuin1) protein levels, ERα (estrogen receptor α), and ERβ (estrogen receptor β) gene expressions (P < 0.001). In contrast, CR declined body weight, IL-6 and TNF-α (P < 0.001), increased IL-10 expressions (P < 0.05), decreased cleaved caspase-3 (P < 0.001), Bax (P < 0.01), and Bax/Bcl2 ratio (P < 0.05), enhanced Bcl-2 (P < 0.001), increased SIRT1 (P < 0.05) and ERα (P < 0.001) and ERβ (P < 0.01) expressions. ConclusionCR through the SIRT1 regulation and estrogen receptors attenuate obesity-induced-cardiac inflammation and apoptosis. CR can be a cardioprotective candidate in postmenopausal conditions.

Estrogen receptor α isoforms generated by alternative use of cryptic exons.

Estrogen receptor α (ERα) regulates several physiological functions. In pathophysiological conditions, ERα is involved in the development and progression of estrogen-sensitive tumors. The ERα gene contains multiple 5'-untranslated exons and eight conventional coding exons and presents multiple isoforms generated by alternative promoter usage and alternative splicing. This gene also possesses non-conventional exons in the 3'- and intronic regions, and alternative use of cryptic exons contributes to further diversity of ERα mRNAs and proteins. Recently, the genomic organization of ERα genes and the splicing profiles of their transcripts were comparatively analyzed in humans, mice, and rats, and multiple ERα isoforms with distinct structures and functions were identified. These transcripts contain cryptic sequences that encode insertion-containing or truncated ERα proteins. In particular, alternative cryptic exons with in-frame stop codons yield transcripts encoding C-terminally-truncated ERα proteins. The C-terminally-truncated ERα isoforms lack part or all of the ligand-binding domain but possess an isoform-specific sequence. Some of these isoforms exhibit constitutive transactivation and resistance to estrogen receptor antagonists. Although numerous studies have reported conflicting results regarding their functions, the critical determinant for their gain-of-function has been identified structurally. Here we review recent progress in ERα variant research concerning the genomic organization of ERα genes, splicing profiles of ERα transcripts, and transactivation properties of ERα isoforms.

Differences in Cholesterol Metabolism, Hepato-Intestinal Aging, and Hepatic Endocrine Milieu in Rats as Affected by the Sex and Age.

Age and sex influence serum cholesterol levels, but the underlying mechanisms remain unclear. To investigate further, we measured cholesterol, precursors (surrogate synthesis markers), degradation products (oxysterols and bile acid precursors) in serum, the liver, jejunum, and ileum, as well as serum plant sterols (intestinal absorption markers) in male and female Wistar rats (4 and 24 months old). The analysis of histomorphometric and oxidative stress parameters (superoxide dismutase, catalase, glutathione-related enzyme activities, lipid peroxide, and protein carbonyl concentrations) in the liver and jejunum offered further insights into the age- and sex-related differences. The hepatic gene expression analysis included AR, ERα, and sex-specific growth hormone-regulated (Cyp2c11 and Cyp2c12) and thyroid-responsive (Dio1, Tbg, and Spot 14) genes by qPCR. We observed age-related changes in both sexes, with greater prominence in females. Aged females had significantly higher serum cholesterol (p < 0.05), jejunum cholesterol (p < 0.05), and serum plant sterols (p < 0.05). They exhibited poorer hepato-intestinal health compared with males, which was characterized by mild liver dysfunction (hydropic degeneration, increased serum ALT, p < 0.05, and decreased activity of some antioxidant defense enzymes, p < 0.05), mononuclear inflammation in the jejunal lamina propria, and age-related decreases in jejunal catalase and glutathione peroxidase activity (p < 0.05). Aged females showed increased levels of 27-hydroxycholesterol (p < 0.05) and upregulated ERα gene expression (p < 0.05) in the liver. Our study suggests that the more significant age-related increase in serum cholesterol in females is associated with poorer hepato-intestinal health and increased jejunal cholesterol absorption. The local increase in 27-hydroxycholesterol during aging might reduce the hepatoprotective effects of endogenous estrogen in the female liver.

Impact of dietary soybean inclusion on the endocrine disruptive effect in female brood stock of Cyprinus carpio

Phytoestrogens, mostly found in legumes, mimic animal estrogens and induce either pro- or anti-estrogenic activity. A feeding trial for matured Cyprinus carpio females was carried out to assess the endocrine disrupting effect of phytoestrogens in SBM and to suggest a dietary inclusion of soybean meal for broodstock of carps. The fish were fed diets containing graded levels of soybean meal (SBM-0, 15, 20, 25, 30, 35, and 40%) for 60 days. To assess the endocrine disruption, sex hormone profiling, gene expression analysis of candidate genes, and histological examinations were conducted. Serum T3, serum vitellogenin, and mRNA levels of cyp19a1, cyp19b, and erβ were found to be higher in fish groups fed with diet containing low levels of SBM (SBM 15, 20, and 25), and significantly lower in high SBM diet (≥30%) fed groups. Serum concentrations of cholesterol, cortisol, and the mRNA level of 20βHSD all decreased as SBM increased. Increased levels of testosterone, estradiol, and the mRNA for the erα gene were observed in the diet when SBM was incorporated into the diet. In the treatment groups with ≥30% inclusion of SBM, the number of vitellogenic oocytes and the gonadosomatic index were significantly lower than the groups with low inclusion levels. Thus, soybean meal can be included in the diet of female carp broodstocks up to 25% without disrupting the reproductive function. However, an inclusion level beyond 25% could harm the endocrine axis, subsequently capable of impacting reproductive performance.

The effect of hesperetin on estrogen receptor gene expression and its relationship with the downstream pathways of estrogen receptor alpha.

Estrogen receptor (ER) is a transcription factor that affects the expression of some genes involved in the progression and development of breast cancer (BC). Hesperetin (Hst) is a flavonoid that inhibits the proliferation of BC cells. In this study, we investigated the effect of Hst on the cell viability of MCF-7 cells and the gene expression of the ERα, ERβ, IL-6, Ps2, and Cyclin D1. In this study, cell viability was determined by MTT assay. The cells were seeded in RPMI-1640 medium and then exposed to different concentrations of Hst (0, 25, 50, 100, 200, and 400 µM) for 24h, and IC50 was calculated. Real-time PCR was used to assess the expression of ERα, ERβ, pS2, Cyclin D1, and IL-6 mRNA. MCF-7 cells were seeded in RPMI-1640 medium and then exposed to different concentrations of Hst (0, 25, 50, 100, and 200 µM) for 24h. Real-time PCR was carried out using a Step One Real-Time PCR System (ABI, USA) and Amplicon SYBR Green reagents. The MTT assay revealed increased cytotoxicity with higher concentrations of Hst, and the IC50 was calculated at 200 µM. Real-time PCR analysis following treatment with Hst showed a significant increase in ERα gene expression at 25 µM of Hst and a decrease in expression at 50, 100, and 200 µM of Hst (p < 0.0001). ERβ gene expression significantly decreased across all concentrations of Hst (p < 0.0001), while IL-6 gene expression decreased significantly in all concentrations (p < 0.0001). pS2 gene expression increased significantly with all concentrations of Hst (p < 0.0001), while Cyclin D1 gene expression did not significantly decrease upon Hst exposure (p > 0.05). The results of our study demonstrate that Hst has the ability to induce cell death in MCF-7 cells. Furthermore, it was observed that Hst reduces the expression of the ER gene and enhances its activity, which can affect the downstream pathways of the ER.

Association of single nucleotide polymorphism of ERα gene and aromatase inhibitor-associated musculoskeletal symptoms

Association of single nucleotide polymorphism of ERα gene and aromatase inhibitor-associated musculoskeletal symptoms

Survival Analysis of Skeletal Related Events in HR+ Breast Cancer Patients Based on Single NucleotidePolymorphism of ERα Gene

Survival Analysis of Skeletal Related Events in HR+ Breast Cancer Patients Based on Single NucleotidePolymorphism of ERα Gene

Effects of Curcumin on GLUT4, Erα and Insulin Resistance Genes Expression in Polycystic Ovary Syndrome Rats

Effects of Curcumin on GLUT4, Erα and Insulin Resistance Genes Expression in Polycystic Ovary Syndrome Rats

Differential effects of continuous and intermittent daytime food deprivation periods on metabolism and reproductive performance in diurnal zebra finches

We investigated whether food availability effects on metabolism and reproduction are the result of the sum effect of daily feeding (food availability) and starvation (food deprivation) periods. Adult zebra finches were paired and subjected to a time-restricted feeding (TRF) regimen consisting of continuous and intermittent daytime food deprivation periods. Birds were given food during the 12-h day for a total of 4-h in the evening (1 *4-h, hour 8–12), or in 2 splits of 2 h each (2 * 2-h) or 4 splits 1 h each (4 * 1-h), with controls on food ad libitum, until they had the first egg clutch. TRF caused significant changes in hepatic expression of metabolism-associated sirt1, egr1, pparα and foxo1 genes despite no difference in the food intake, body mass and blood glucose levels. Importantly, TRF resulted in a significant reduction in plasma testosterone and estradiol levels, delayed nest-building and egg laying, and reduced clutch size. Concurrently, under TRF regimes, we found a significantly lower expression of th and mtr genes linked with motivation and affiliation (but not of dio2, dio3, gnrh1 and gnih genes linked with gonadal maturation) in the hypothalamus, and of star and hook 1 genes in the testes and star, cyp19 and erα genes in the ovary. These results demonstrate the importance of daily food deprivation times on the metabolism and reproduction, and suggest a possible provisioning of energy available from daily feeding for the maintenance of body condition at the expense of reproduction performance in diurnal animals.

Estrogen Receptor Alpha Splice Variants, Post-Translational Modifications, and Their Physiological Functions

The importance of estrogenic signaling for a broad spectrum of biological processes, including reproduction, cancer development, energy metabolism, memory and learning, and so on, has been well documented. Among reported estrogen receptors, estrogen receptor alpha (ERα) has been known to be a major mediator of cellular estrogenic signaling. Accumulating evidence has shown that the regulations of ERα gene transcription, splicing, and expression across the tissues are highly complex. The ERα promoter region is composed of multiple leader exons and 5'-untranslated region (5'-UTR) exons. Differential splicing results in multiple ERα proteins with different molecular weights and functional domains. Furthermore, various post-translational modifications (PTMs) further impact ERα cellular localization, ligand affinity, and therefore functionality. These splicing isoforms and PTMs are differentially expressed in a tissue-specific manner, mediate certain aspects of ERα signaling, and may work even antagonistically against the full-length ERα. The fundamental understanding of the ERα splicing isoforms in normal physiology is limited and association studies of the splicing isoforms and the PTMs are scarce. This review aims to summarize the functional diversity of these ERα variants and the PTMs in normal physiological processes, particularly as studied in transgenic mouse models.