25-hydroxycholesterol promotes proliferation and metastasis of lung adenocarcinoma cells by regulating ERß/TNFRSF17 axis.

Lung adenocarcinoma is the main type of lung cancer in women. Our previous findings have evidenced that 25-hydroxycholesterol (25-HC) promotes migration and invasion of lung adenocarcinoma cells (LAC), during which LXR as a 25-HC receptor plays an important role. Estrogen receptor beta (ERß) is a receptor of 27-hydroxycholesterol that is structurally analogous to 25-HC, but its role in the functional actions of 25-HC remained largely unknown. In this study, we demonstrated that 25-HC treatment triggered ERß expression in LAC. Knockdown of ERß inhibited 25-HC-mediated proliferation, migration and invasion, and reduced 25-HC-induced LAC metastasis in vivo. Further investigation revealed that ERß knockdown restrained the expression of TNFRSF17 (BCMA). In vivo experiments also confirmed that ERß knockdown blocked 25-HC-induced TNFRSF17 expression. TNFRSF17 knockdown also restrained 25-HC-induced proliferation, migration and invasion. Bioinformatic analysis showed that the levels of ERß and TNFRSF17 were elevated in lung adenocarcinoma, and were closely related to tumor stages and nodal metastasis status. These results suggested that 25-HC promoted the proliferation and metastasis of LAC by regulating ERß/TNFRSF17 axis.

Silver ciprofloxacin (CIPAG): a multitargeted metallodrug in the development of breast cancer therapy.

The anti-proliferative activity of the known metalloantibiotic {[Ag(CIPH)2]NO3∙0.75MeOH∙1.2H2O} (CIPAG) (CIPH = ciprofloxacin) against the human breast adenocarcinoma cancer cells MCF-7 (hormone dependent (HD)) and MDA-MB-231 (hormone independent (HI)) is evaluated. The in vitro toxicity and genotoxicity of the metalloantibiotic were estimated toward fetal lung fibroblast (MRC-5) cells. The molecular mechanism of the CIPAG activity against MCF-7 cells was clarified by the (i) cell morphology, (ii) cell cycle arrest, (iii) mitochondrial membrane permeabilization, and (iv) by the assessment of the possible differential effect of CIPAG on estrogen receptor alpha (ERα) and estrogen receptor beta (ERß) transcriptional activation, applying luciferase reporter gene assay. Moreover, the ex vivo mechanism of CIPAG was clarified by its binding affinity toward calf thymus (CT-DNA).

Genistin: A Novel Estrogen Analogue Targeting ERß to Alleviate Thrombocytopenia.

Thrombocytopenia, a prevalent hematologic challenge, correlates directly with the mortality of numerous ailments. Current therapeutic avenues for thrombocytopenia are not without limitations. Here, we identify genistin, an estrogen analogue, as a promising candidate for thrombocytopenia intervention, discovered through AI-driven compound library screening. While estrogen's involvement in diverse biological processes is recognized, its role in thrombopoiesis remains underexplored. Our findings elucidate genistin's ability to enhance megakaryocyte differentiation, thereby augmenting platelet formation and production. In vivo assessments further underscore genistin's remedial potential against radiation-induced thrombocytopenia. Mechanistically, genistin's efficacy is attributed to its direct interaction with estrogen receptor ß (ERß), with subsequent activation of both ERK1/2 and the Akt signaling pathways membrane ERß. Collectively, our study positions genistin as a prospective therapeutic strategy for thrombocytopenia, shedding light on novel interplays between platelet production and ERß.

Changes in ovarian tissue structure and distribution of oestrogen receptors in Huanghuai goats at different ages.

To observe developmental changes in the ovarian tissue structure and distribution characteristics of oestrogen receptors (ERs) in the ovaries of Huanghuai goats at different ages, we selected healthy Huanghuai goats ewes and divided them into five groups (i.e. 3-, 30-, 60-, 90- and 120-day-old groups), with 10 animals in each group. The serum was separated after blood collection through the jugular vein, and the contents of oestrogen (E) and progesterone (P) in the serum of Huanghuai goats at each age were determined. Three goats were randomly selected from each group and sacrificed after anaesthesia, and the ovarian tissue was quickly obtained and placed in 4% paraformaldehyde fixative to prepare the tissue sections. Using HE, oestrogen receptors were immunohistochemically stained and observed. These results showed many primordial follicles and occasional secondary follicles in the ovaries of 3-day-old Huanghuai goats. Ovarian reticular structures were observed in 30-day-old ovarian medulla, with occasional near-mature growing follicles. Mature follicles and corpus luteum were occasionally detected in 60-day-old ovarian cortex. The 90-120-day-old ovarian cortices contained growing and mature follicles, and the number of mature follicles and corpora lutea increased, implying a significant luteal involution period. The E and P contents in the 120-day-old group were significantly higher than those in the 3-, 30-, 60- and 90-day-old groups. The levels of ERα and ERß in the 3- and 30-day-old groups were mainly distributed in the granulosa cells of ovarian reproductive epithelial cells, primordial follicles, atretic follicles, and primary and secondary follicles. The ERα and ERß levels of the 60-, 90- and 120-day-old groups were also distributed in the granulosa cells and luteal cells of mature follicles, especially in the 120-day-old endometrial cells of mature follicles, where ERß was distributed significantly. The overall expression of ERß in the ovary was higher than that of ERα. The results of this study provide basic data on the ovarian development and the specific expression of ERs and PRs in the ovaries of Huanghuai white goats, which play an important role in ovarian development and precocity.

Molecular insights into the potential effects of selective estrogen receptor ß agonists in Alzheimer's and Parkinson's diseases.

Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common neurodegenerative disorders. Pathologically, AD and PD are characterized by the accumulation of misfolded proteins. Hence, they are also called as proteinopathy diseases. Gender is considered as one of the risk factors in both diseases. Estrogens are widely accepted to be neuroprotective in several neurodegenerative disorders. Estrogens can be produced in the central nervous system, where they are called as neurosteroids. Estrogens mediate their neuroprotective action mainly through their actions on estrogen receptor alpha (ERα) and estrogen receptor beta (ERß). However, ERα is mainly involved in the growth and development of the primary and secondary sexual organs in females. Hence, the activation of ERα is associated with undesired side effects such as gynecomastia and increase in the risk of breast cancer, thromboembolism, and feminization. Therefore, selective activation of ERß is often considered to be safer. In this review, we explore the role of ERß in regulating the expression and functions of AD- and PD-associated genes. Additionally, we discuss the association of these genes with the amyloid-beta peptide (Aß) and α-synuclein mediated toxicity. Ultimately, we established a correlation between the importance of ERß activation and the process underlying ERß's neuroprotective mechanisms in AD and PD.

ERß Regulation of Indian Hedgehog Expression in the First Wave of Ovarian Follicles.

Increased activation of ovarian primordial follicles in Erß knockout (ErßKO) rats becomes evident as early as postnatal day 8.5. To identify the ERß-regulated genes that may control ovarian primordial follicle activation, we analyzed the transcriptome profiles of ErßKO rat ovaries collected on postnatal days 4.5, 6.5, and 8.5. Compared to wildtype ovaries, ErßKO ovaries displayed dramatic downregulation of Indian hedgehog (Ihh) expression. IHH-regulated genes, including Hhip, Gli1, and Ptch1, were also downregulated in ErßKO ovaries. This was associated with a downregulation of steroidogenic enzymes Cyp11a1, Cyp19a1, and Hsd17b1. The expression of Ihh remained very low in ErßKO ovaries despite the high levels of Gdf9 and Bmp15, which are known upregulators of Ihh expression in the granulosa cells of activated ovarian follicles. Strikingly, the downregulation of the Ihh gene in ErßKO ovaries began to disappear on postnatal day 16.5 and recovered on postnatal day 21.5. In rat ovaries, the first wave of primordial follicles is rapidly activated after their formation, whereas the second wave of primordial follicles remains dormant in the ovarian cortex and slowly starts activating after postnatal day 12.5. We localized the expression of Ihh mRNA in postnatal day 8.5 wildtype rat ovaries but not in the age-matched ErßKO ovaries. In postnatal day 21.5 ErßKO rat ovaries, we detected Ihh mRNA mainly in the activated follicles in the ovaries' peripheral regions. Our findings indicate that the expression of Ihh in the granulosa cells of the activated first wave of ovarian follicles depends on ERß.

Estrogen α and ß Receptor Expression in the Various Regions of Resected Glioblastoma Multiforme Tumors and in an In Vitro Model.

Glioblastoma multiforme (GBM) is a malignant tumor with a higher prevalence in men and a higher survival rate in transmenopausal women. It exhibits distinct areas influenced by changing environmental conditions. This study examines how these areas differ in the levels of estrogen receptors (ERs) which play an important role in the development and progression of many cancers, and whose expression levels are often correlated with patient survival. This study utilized two research models: an in vitro model employing the U87 cell line and a second model involving tumors resected from patients (including tumor core, enhancing tumor region, and peritumoral area). ER expression was assessed at both gene and protein levels, with the results validated using confocal microscopy and immunohistochemistry. Under hypoxic conditions, the U87 line displayed a decrease in ERß mRNA expression and an increase in ERα mRNA expression. In patient samples, ERß mRNA expression was lower in the tumor core compared to the enhancing tumor region (only in males when the study group was divided by sex). In addition, ERß protein expression was lower in the tumor core than in the peritumoral area (only in women when the study group was divided by sex). Immunohistochemical analysis indicated the highest ERß protein expression in the enhancing tumor area, followed by the peritumoral area, and the lowest in the tumor core. The findings suggest that ER expression may significantly influence the development of GBM, exhibiting variability under the influence of conditions present in different tumor areas.

Altered Glycolysis, Mitochondrial Biogenesis, Autophagy and Apoptosis in Peritoneal Endometriosis in Adolescents.

Energy metabolism plays a pivotal role in the pathogenesis of endometriosis. For the initial stages of the disease in adolescents, this aspect remains unexplored. The objective of this paper was to analyze the association of cellular and endosomal profiles of markers of glycolysis, mitochondrial biogenesis, apoptosis, autophagy and estrogen signaling in peritoneal endometriosis (PE) in adolescents. We included 60 girls aged 13-17 years in a case-control study: 45 with laparoscopically confirmed PE (main group) and 15 with paramesonephric cysts (comparison group). Samples of plasma and peritoneal fluid exosomes, endometrioid foci and non-affected peritoneum were tested for estrogen receptor (Erα/ß), hexokinase (Hex2), pyruvate dehydrogenase kinase (PDK1), glucose transporter (Glut1), monocarboxylate transporters (MCT1 and MCT2), optic atrophy 1 (OPA1, mitochondrial fusion protein), dynamin-related protein 1 (DRP1, mitochondrial fission protein), Bax, Bcl2, Beclin1, Bnip3, P38 mitogen-activated protein kinase (MAPK), hypoxia-inducible factor 1 (Hif-1α), mitochondrial voltage-dependent anion channel (VDAC) and transforming growth factor (TGFß) proteins as markers of estrogen signaling, glycolysis rates, mitochondrial biogenesis and damage, apoptosis and autophagy (Western-Blot and PCR). The analysis identified higher levels of molecules associated with proliferation (ERß), glycolysis (MCT2, PDK1, Glut1, Hex2, TGFß and Hif-1α), mitochondrial biogenesis (OPA1, DRP1) and autophagy (P38, Beclin1 and Bnip3) and decreased levels of apoptosis markers (Bcl2/Bax) in endometrioid foci compared to non-affected peritoneum and that in the comparison group (p < 0.05). Patients with PE had altered profiles of ERß in plasma and peritoneal fluid exosomes and higher levels of Glut1, MCT2 and Bnip3 in plasma exosomes (p < 0.05). The results of the differential expression profiles indicate microenvironment modification, mitochondrial biogenesis, estrogen reception activation and glycolytic switch along with apoptosis suppression in peritoneal endometrioid foci already in adolescents.

Protecting the Brain: Novel Strategies for Preventing Breast Cancer Brain Metastases through Selective Estrogen Receptor ß Agonists and In Vitro Blood-Brain Barrier Models.

Breast cancer brain metastasis (BCBM) is a challenging condition with limited treatment options and poor prognosis. Understanding the interactions between tumor cells and the blood-brain barrier (BBB) is critical for developing novel therapeutic strategies. One promising target is estrogen receptor ß (ERß), which promotes the expression of key tight junction proteins, sealing the BBB and reducing its permeability. In this study, we investigated the effects of 17ß-estradiol (E2) and the selective ERß agonist diarylpropionitrile (DPN) on endothelial and cancer cells. Western blot analysis revealed the expression patterns of ERs in these cell lines, and estrogen treatment upregulated claudin-5 expression in brain endothelial cells. Using in vitro models of the BBB, we found that DPN treatment significantly increased BBB tightness about suppressed BBB transmigration activity of representative Her2-positive (BT-474) and triple-negative (MDA-MB-231) breast cancer cell lines. However, the efficacy of DPN treatment decreased when cancer cells were pre-differentiated in the presence of E2. Our results support ERß as a potential target for the prevention and treatment of BCBM and suggest that targeted vector-based approaches may be effective for future preventive and therapeutic implications.

Linking alterations in estrogen receptor expression to memory deficits and depressive behavior in an ovariectomy mouse model.

The high risk of neurological disorders in postmenopausal women is an emerging medical issue. Based on the hypothesis of altered estrogen receptors (ERα and ß) after the decline of estrogen production, we investigated the changes in ERs expressions across brain regions and depressive/amnesic behaviors. C57BL/6J female mice were ovariectomized (OVX) to establish a menopausal condition. Along with behavior tests (anxiety, depression, and memory), the expression of ERs, microglial activity, and neuronal activity was measured in six brain regions (hippocampus, prefrontal cortex, striatum, raphe nucleus, amygdala, and hypothalamus) from 4 to 12 weeks after OVX. Mice exhibited anxiety- and depressive-like behaviors, as well as memory impairment. These behavioral alterations have been linked to a suppression in the expression of ERß. The decreased ERß expression coincided with microglial-derived neuroinflammation, as indicated by notable activations of Ionized calcium-binding adapter molecule 1 and Interleukin-1beta. Additionally, the activity of brain-derived neurotrophic factor (BDNF), particularly in the hippocampus, decreased in a time-dependent manner from 4 to 12 weeks post-OVX. Our study provides evidence shedding light on the susceptibility to memory impairment and depression in women after menopause. This susceptibility is associated with the suppression of ERß and alteration of ERα in six brain regions.

Activation of ERß hijacks the splicing machinery to trigger R-loop formation in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with aggressive behavior and poor prognosis. Current therapeutic options available for TNBC patients are primarily chemotherapy. With our evolving understanding of this disease, novel targeted therapies, including poly ADP-ribose polymerase (PARP) inhibitors, antibody-drug conjugates, and immune-checkpoint inhibitors, have been developed for clinical use. Previous reports have demonstrated the essential role of estrogen receptor ß (ERß) in TNBC, but the detailed molecular mechanisms downstream ERß activation in TNBC are still far from elucidated. In this study, we demonstrated that a specific ERß agonist, LY500307, potently induces R-loop formation and DNA damage in TNBC cells. Subsequent interactome experiments indicated that the residues 151 to 165 of U2 small nuclear RNA auxiliary factor 1 (U2AF1) and the Trp439 and Lys443 of ERß were critical for the binding between U2AF1 and ERß. Combined RNA sequencing and ribosome sequencing analysis demonstrated that U2AF1-regulated downstream RNA splicing of 5-oxoprolinase (OPLAH) could affect its enzymatic activity and is essential for ERß-induced R-loop formation and DNA damage. In clinical samples including 115 patients from The Cancer Genome Atlas (TCGA) and 32 patients from an in-house cohort, we found a close correlation in the expression of ESR2 and U2AF1 in TNBC patients. Collectively, our study has unraveled the molecular mechanisms that explain the therapeutic effects of ERß activation in TNBC, which provides rationale for ERß activation-based single or combined therapy for patients with TNBC.

A direct estrogenic involvement in the expression of human hypocretin.

Hypocretin is synthesized exclusively in the hypothalamus and distributes inputs to several areas of the brain, which may play an important role in depression. Our previous study showed that hypocretin-1 was increased in the lateral hypothalamus in female patients with depression compared to female controls. Estrogen acts through estrogen receptor (ER)α and ERß. We studied the possibility of a direct action of estrogen receptors on the expression of human hypocretin. We found that hypocretin-1 plasma levels were significantly higher in female patients with depression than in female controls. Female depression estrogen receptors and hypocretin are colocalized in the human lateral hypothalamus, PC12, and SK-N-SH cells. The estrogen receptor response elements (ERE) that exist in the hypocretin promoter region may directly regulate the gene expression of hypocretin. The synchronicity of change of hypocretin and estradiol both in hypothalamus and plasma was verified in female rats. In the presence of estradiol, specific binding occurs between the recombinant human ER and hypocretin-ERE. Expression of ER combined with estradiol repressed hypocretin promoter activity via the ERE. In conclusion, we found that estradiol may directly affect hypocretin neurons in the human hypothalamus via ER binding to the hypocretin-ERE, which may lead to the sex-specific pathogenesis of depression.

High Oestrogen receptor alpha expression correlates with adverse prognosis and promotes metastasis in colorectal cancer.

In normal colon tissue, oestrogen receptor alpha (ERα) is expressed at low levels, while oestrogen receptor beta (ERß) is considered the dominant subtype. However, in colon carcinomas, the ERα/ß ratio is often increased, an observation that prompted us to further investigate ERα's role in colorectal cancer (CRC). Here, we assessed ERα nuclear expression in 351 CRC patients. Among them, 119 exhibited positive ERα nuclear expression, which was significantly higher in cancer tissues than in matched normal tissues. Importantly, patients with positive nuclear ERα expression had a poor prognosis. Furthermore, positive ERα expression correlated with increased levels of the G-protein coupled cysteinyl leukotriene receptor 1 (CysLT1R) and nuclear ß-catenin, both known tumour promoters. In mouse models, ERα expression was decreased in Cysltr1-/- CAC (colitis-associated colon cancer) mice but increased in ApcMin/+ mice with wild-type Cysltr1. In cell experiments, an ERα-specific agonist (PPT) increased cell survival via WNT/ß-catenin signalling. ERα activation also promoted metastasis in a zebrafish xenograft model by affecting the tight junction proteins ZO-1 and Occludin. Pharmacological blockade or siRNA silencing of ERα limited cell survival and metastasis while restoring tight junction protein expression. In conclusion, these findings highlight the potential of ERα as a prognostic marker for CRC and its role in metastasis.

Synergistic Anti-Cancer Effects of ERB-041 and Genistein through Estrogen Receptor Suppression-Mediated PI3K/AKT Pathway Downregulation in Canine Mammary Gland Tumor Cells.

Canine-mammary-gland tumors (CMTs) are prevalent in female dogs, with approximately 50% of them being malignant and often presenting as inoperable owing to their size or metastasis. Owing to poor outcomes, effective alternatives to conventional chemotherapy for humans are necessary. Two estrogen receptors, estrogen receptor alpha (ERα) and estrogen receptor beta (ERß), which act in opposition to each other, are involved, and CMT growth involves ERα through the phosphoinositide 3-kinases (PI3K)/AKT pathway. In this study, we aimed to identify the synergistic anti-cancer effects of ERB-041, an ERß agonist, and genistein, an isoflavonoid from soybeans known to have ERß-specific pseudo-estrogenic actions, on CMT-U27 and CF41.Mg CMT cell lines. ERB-041 and genistein synergistically inhibited cell proliferation and increased the number of annexin V-positive cells in both cell lines. Furthermore, we observed a synergistic increase in the Bax/Bcl-2 ratio and cleaved caspase-3 expression. Additionally, cell-cycle arrest occurred through the synergistic regulation of cyclin D1 and cyclin-dependent kinase 4 (CDK4). We also found a synergistic decrease in the expression of ERα, and the expression of proteins involved in the PI3K/AKT pathway, including p-PI3K, phosphatase and tensin homolog (PTEN), AKT, and mechanistic target of rapamycin (mTOR). In conclusion, ERB-041 and genistein exhibited a synergistic anticancer effect on CMTs, suggesting that cotreatment with ERB-041 and genistein is a promising treatment for CMTs.

Bone-Differentiation-Associated Circ-Spen Regulates Death of Mouse Bone Marrow Mesenchymal Stem Cells by Inhibiting Apoptosis and Promoting Autophagy.

The role of estrogen receptor ß (ERß) in bone health is closely associated with its function in vivo, and ERß-/- mice have been widely utilized to explore the related influences. In this study, ERß-/- female mice were established to investigate the differential expression of circular RNAs (circRNAs) by RNA-Sequencing (RNA-Seq). Among these circRNAs, mmu_circ_0011379 (named Circ-Spen) exhibited high expression in ERß-/- female mice. However, the precise mechanism by which Circ-Spen regulates bone health remained unclear. This study identified Circ-Spen as a positive regulator of mouse bone marrow mesenchymal stem cell (mBMSC) viability. The expression of Circ-Spen was markedly increased in ERß-/- mice femurs tested by RT-qPCR. Moreover, Circ-Spen exhibited an enhanced expression during the bone formation process of mBMSCs. Qualitative experiments also demonstrated that Circ-Spen possessed a circular structure and was localized within the nucleus of mBMSCs. Functionally, it inhibited apoptosis via caspase-3, BCL-2, and BAX, while also promoting autophagy through BECN1 and P62 in mBMSCs tested by MTT assays, transmission electron microscopy (TEM), and Western blotting. These findings reveal the potential of targeting Circ-Spen as a promising therapeutic strategy for rejuvenating senescent mBMSCs and enhancing the efficiency of mBMSC transplantation, which lays the foundation for advancements in the field of bone therapy.

Development of Cytotoxic GW7604-Zeise's Salt Conjugates as Multitarget Compounds with Selectivity for Estrogen Receptor- Positive Tumor Cells.

(E/Z)-3-(4-((E)-1-(4-Hydroxyphenyl)-2-phenylbut-1-enyl)phenyl)acrylic acid (GW7604) as a carrier was esterified with alkenols of various lengths and coordinated through the ethylene moiety to PtCl3, similar to Zeise's salt (K[PtCl3(C2H4)]). The resulting GW7604-Alk-PtCl3 complexes (Alk = Prop, But, Pent, Hex) degraded in aqueous solution only by exchange of the chlorido ligands. For example, GW7604-Pent-PtCl3 coordinated the amino acid alanine in the cell culture medium, bound the isolated nucleotide 5'-GMP, and interacted with the DNA (empty plasmid pSport1). It accumulated in estrogen receptor (ER)-positive MCF-7 cells primarily via cytosolic vesicles, while it was only marginally taken up in ER-negative SKBr3 cells. Accordingly, GW7604-Pent-PtCl3 and related complexes were inactive in SKBr3 cells. GW7604-Pent-PtCl3 showed high affinity to ERα and ERß without mediating agonistic or ER downregulating properties. GW7604-Alk ligands also increased the cyclooxygenase (COX)-2 inhibitory potency of the complexes. In contrast to Zeise's salt, the GW7604-Alk-PtCl3 complexes inhibited COX-1 and COX-2 to the same extent.

Loss of ERß Disrupts Gene Regulation in Primordial and Primary Follicles.

Loss of ERß increases primordial follicle growth activation (PFGA), leading to premature ovarian follicle reserve depletion. We determined the expression and gene regulatory functions of ERß in dormant primordial follicles (PdFs) and activated primary follicles (PrFs) using mouse models. PdFs and PrFs were isolated from 3-week-old Erß knockout (Erßnull) mouse ovaries, and their transcriptomes were compared with those of control Erßfl/fl mice. We observed a significant (≥2-fold change; FDR p-value ≤ 0.05) deregulation of approximately 5% of genes (866 out of 16,940 genes, TPM ≥ 5) in Erßnull PdFs; ~60% (521 out of 866) of the differentially expressed genes (DEGs) were upregulated, and 40% were downregulated, indicating that ERß has both transcriptional enhancing as well as repressing roles in dormant PdFs. Such deregulation of genes may make the Erßnull PdFs more susceptible to increased PFGA. When the PdFs undergo PFGA and form PrFs, many new genes are activated. During PFGA of Erßfl/fl follicles, we detected a differential expression of ~24% genes (4909 out of 20,743; ≥2-fold change; FDR p-value ≤ 0.05; TPM ≥ 5); 56% upregulated and 44% downregulated, indicating the gene enhancing and repressing roles of Erß-activated PrFs. In contrast, we detected a differential expression of only 824 genes in Erßnull follicles during PFGA (≥2-fold change; FDR p-value ≤ 0.05; TPM ≥ 5). Moreover, most (~93%; 770 out of 824) of these DEGs in activated Erßnull PrFs were downregulated. Such deregulation of genes in Erßnull activated follicles may impair their inhibitory role on PFGA. Notably, in both Erßnull PdFs and PrFs, we detected a significant number of epigenetic regulators and transcription factors to be differentially expressed, which suggests that lack of ERß either directly or indirectly deregulates the gene expression in PdFs and PrFs, leading to increased PFGA.

Allelic variants of the estrogen receptor genes and frailty phenotype in postmenopausal women.

OBJECTIVE: The prevalence of frailty has been related to menopause. Our main objective was to investigate whether single nucleotide polymorphisms (SNPs) of the estrogen receptor (ER) ERα and ERß genes were related to the frailty phenotype in a population of community-dwelling postmenopausal women. METHODS: A cross-sectional study was performed in which we selected five SNPs, three in the ERα gene and two in the ERß. Linear regression was used to estimate the percentage of phenotypic variance after adjusting for confounding variables. RESULTS: A total of 470 women (mean ± standard deviation age 63.83 ± 8.16 years) were included, of whom 137 women were frail. The SNP rs3798577 of the ERα gene was the only variant associated with frailty, but this significance faded in the multivariant analysis. Body mass index (p = 0.012), number of comorbidities (0 vs. ≥2, p = 0.002) and two reproductive variables, number of miscarriages (none vs. ≥2, p = 0.036) and of childbirths (one vs. ≥3, p = 0.008), were independently related to frailty. CONCLUSION: The five SNPs of the ERα and ERß genes tested were not correlated with frailty. Other SNPs of the ER warrant analysis to clarify whether variance in the gene response affects frailty status.

Association of estrogen receptor and progesterone receptor genetic polymorphisms with recurrent pregnancy loss: A systematic review and meta-analysis.

OBJECTIVE: Estrogen and progesterone play key roles in the maintenance of pregnancy, and their function is mediated via estrogen receptor 1 (ESR1)/estrogen receptor 2 (ESR2) and progesterone receptor (PGR), respectively. It has been suggested the genetic variations in ESR1, ESR2, and PGR may contribute to recurrent pregnancy loss (RPL); however, the available evidence remains controversial. This meta-analysis aimed to explore the relation of various polymorphisms in ESR1, ESR2, and PGR genes to the risk of RPL. METHODS: A systematic literature search was conducted using PubMed and Scopus up to August 2023 to obtain relevant studies. The odds ratios (ORs) with 95% confidence intervals (95% CIs) were computed and pooled with the use of random-effects models to test the associations. RESULTS: A total of 31 studies with 12 different polymorphisms, including 5 polymorphisms for ESR1, 3 polymorphisms for ESR2, and 4 polymorphisms for PGR, were analyzed in this meta-analysis. Overall, no significant relationship was found between various polymorphisms of ESR1 and ESR2 with RPL in any of the genetic analysis models. PGR rs590688 (C > G) polymorphism was significantly related to the elevated risk of RPL under the dominant (OR = 1.67; 95 %CI: 1.15-2.44), allelic (OR = 1.55; 95 %CI: 1.13-2.12), and GC vs. CC (OR = 1.55; 95 %CI: 1.07-2.23) models. No significant association was identified for other variants of PGR gene. CONCLUSION: Unlike estrogen receptors, variations in PGR rs590688 (C > G) may be linked to the increased risk of RPL. More studies are required to confirm this finding.

Estrogen-mediated coupling via gap junctions in the suprachiasmatic nucleus.

The circadian clock orchestrates many physiological and behavioural rhythms in mammals with 24-h periodicity, through a hierarchical organisation, with the central clock located in the suprachiasmatic nucleus (SCN) in the hypothalamus. The circuits of the SCN generate circadian rhythms with precision, relying on intrinsic coupling mechanisms, for example, neurotransmitters like arginine vasopressin (AVP), vasoactive intestinal peptide (VIP), neuronal gamma-aminobutyric acid (GABA) signalling and astrocytes connected by gap junctions composed of connexins (Cx). In female rodents, the presence of estrogen receptors (ERs) in the dorsal SCN suggests an influence of estrogen (E2) on the circuit timekeeping that could regulate circadian rhythm and coupling. To investigate this, we used SCN explants together with hypothalamic neurons and astrocytes. First, we showed that E2 stabilised the circadian amplitude in the SCN when rAVPs (receptor-associated vasopressin peptides) were inhibited. However, the phase delay induced by VIPAC2 (VIP receptors) inhibition remained unaffected by E2. We then showed that E2 exerted its effects in the SCN via ERß (estrogen receptor beta), resulting in increased expression of Cx36 and Cx43. Notably, specific inhibition of both connexins resulted in a significant reduction in circadian amplitude within the SCN. Remarkably, E2 restored the period with inhibited Cx36 but not with Cx43 inhibition. This implies that the network between astrocytes and neurons, responsible for coupling in the SCN, can be reinforced through E2. In conclusion, these findings provide new insights into how E2 regulates circadian rhythms ex vivo in an ERß-dependent manner, underscoring its crucial role in fortifying the SCN's rhythm.