Activation Of ERβ Research Articles

Estrogen receptors modulate ectonucleotidases activity in hippocampal synaptosomes of male rats

Extracellular adenine nucleotides and nucleosides, such as adenosine-5'-triphosphate (ATP) and adenosine, are among least investigated signaling factors that participate in 17β-estradiol (E2)-mediated synaptic rearrangements in rodent hippocampus. Their levels in the extrasynaptic space are tightly controlled by ecto-nucleoside triphosphate diphosphohydrolases1-3 (NTPDase1-3)/ecto-5'-nucleotidase (eN) enzyme chain. Therefore, the aim of the present study was to get closer insight in the E2-induced decrease in NTPDase and eN activity in the hippocampal synaptic compartment of male rats and to identify estradiol receptors (ERs i.e. ERα, ERβ or GPER1) responsible for the observed effects of E2. In this study we show indiscriminate participation of estradiol receptor α (ERα), -β (ERβ) and G- protein coupled estrogen receptor 1 (GPER1) in the mediation of E2 actions in hippocampal synaptosomes of male rats. Synaptic NTPDase1-3 activities are modulated only through activation of ERβ, while activation of ERα, -β and/or non-classical GPER1 decreases synaptic eN activity. Since both ATP and adenosine function as neuromodulators in the hippocampal networks, influencing its function, profound knowledge of mechanisms by which ectonucleotidases are regulated/modulated is of great importance.

ERβ Accelerates Diabetic Wound Healing by Ameliorating Hyperglycemia-Induced Persistent Oxidative Stress.

Delayed wound healing in diabetic patients is a serious diabetic complication, resulting in major health problems as well as high mortality and disability. The detailed mechanism still needs to be fully understood. In this study, we aim to investigate potential mechanisms and explore an efficient strategy for clinical treatment of diabetic wound healing. Human umbilical endothelial cells were exposed to hyperglycemia for 4 days, then switched to normoglycemia for an additional 4 days. The cells were harvested for the analysis of reactive oxygen species (ROS) generation, gene expression and VEGF signaling pathway. Furthermore, the diabetic wound model was established in rats for the evaluation of wound healing rates under the treatment of either ERβ agonist/antagonist or SOD mimetic MnTBAP. Our results show that transient hyperglycemia exposure results in persistent ROS overgeneration after the switch to normoglycemia, along with suppressed expression of ERβ, SOD2, and the VEGF signaling pathway. Either ERβ expression or activation diminishes ROS generation. In vivo experiments with diabetic rats show that ERβ activation or SOD mimetic MnTBAP diminishes ROS generation in tissues and accelerates diabetic wound healing. Transient hyperglycemia exposure induces ROS generation and suppresses ERβ expression, subsequently resulting in SOD2 suppression with additional elevated ROS generation. This forms a positive-feed forward loop for ROS generation with persistent oxidative stress. ERβ expression or activation breaks this loop and ameliorates this effect, thereby accelerating diabetic wound healing. We conclude that ERβ accelerates diabetic wound healing by ameliorating hyperglycemia-induced persistent oxidative stress. This provides a new strategy for clinical treatment of diabetic wound healing based on ERβ activation.

Ameliorative effects of Radix rehmanniae extract on the anxiety- and depression-like symptoms in ovariectomized mice: A behavioral and molecular study

BackgroundMenopause is closely associated with the risk of anxiety and depression in a woman's life. Despite the numerous reports on the effects of Radix rehmanniae extract (RRE) on various types of depression, there are few studies exploring the effects of RRE on the menopausal anxiety and depression. PurposeTo investigate whether RRE could alleviate the menopausal anxiety and depression in ovariectomized (OVX) mice submitted to chronic unpredictable mild stress (CUMS). MethodsOVX mice were treated with 2.6 g/kg RRE for 5 weeks. After a series of behavior tests, serum, uterus, and brain tissues were collected for the measurement of neurotransmitters and their related biomarkers, neurotrophins, and estrogen receptor α (ERα) and β (ERβ). ResultsRRE showed antidepressant and anxiolytic effects through these behavior tests, but had no effects on the OVX-induced weight gains, uterine shrinkage and drop of serum estrogen level. RRE restored the levels of serotonin (5-HT), dopamine (DA) and its metabolite 3,4-dihydroxyphenylacetic acid (DOPAC), Glutamate (Glu), gamma-Aminobutyric acid (GABA) and their related biomarkers in different brain regions. RRE also reversed OVX-induced decrease in the expression levels of neurotrophins in uterus and brain regions except for uterine nerve growth factor (NGF). Moreover, RRE restored and even enhanced ERβ expression levels in uterus and brain without affecting uterine, hippocampal and cortical ERα. ConclusionThis study demonstrated the antidepressant and anxiolytic effects of RRE in OVX mice, which were possibly mediated via their modulation of brain neurotransmitters, and regulation of neurotrophins and activation of ERβ.

Saikosaponin‑D improves fear memory deficits in ovariectomized rats via the action of estrogen receptor‑α in the hippocampus.

Saikosaponin‑D (SSD), which is the main bioactive component in the traditional Chinese medicine Chai Hu (Bupleurumfalcatum L), possesses estrogen‑like properties and is widely used in treating estrogen‑related neurological disorders. The current study aimed to investigate the protective effects of SSD on the fear memory deficit in ovariectomized (OVX) rats and the potential underlying mechanism. SSD treatment significantly prolonged freezing time in OVX rats in a manner similar to that of estradiol (E2), whereas this effect was markedly suppressed by co‑administration of ICI182780, a non‑selective estrogen receptor (ER) inhibitor. The expression of ERα in the hippocampus of OVX rats was significantly elevated by SSD; however, Erβ expression and E2 synthesis were not markedly affected by SSD treatment. Collectively, this study demonstrated that SSD‑mediated fear memory improvement in OVX rats may be attributed not to E2 levels or ERβ activity, but to ERα activation in the hippocampus.

Rhododendrin-Induced RNF146 Expression via Estrogen Receptor β Activation is Cytoprotective Against 6-OHDA-Induced Oxidative Stress.

Ring finger protein 146 (RNF146) is an E3 ubiquitin ligase whose activity prevents poly (ADP-ribose) polymerase 1 (PARP1)-dependent neurodegeneration in Parkinson’s disease (PD). Previously, we reported that rhododendrin is a chemical inducer that increases RNF146 expression. However, the molecular mechanism of rhododendrin-induced RNF146 expression is largely unknown and its translational application for the treatment of Parkinson’s disease remains unexplored. Here we found that rhododendrin increased RNF146 expression via estrogen receptor β (ERβ) activation. Rhododendrin stimulated ERβ nuclear translocation and binding to the RNF146 promoter, thereby enhancing its transcription. Rhododendrin is cytoprotective against 6-hydroxydopamine (6-OHDA)-induced cell death, which is largely dependent on ERβ activity and RNF146 expression. Finally, we demonstrated that rhododendrin treatment resulted in RNF146 expression in dopaminergic neurons in mice. Moreover, dopaminergic neuron viability was markedly enhanced by pretreatment with rhododendrin in 6-OHDA-induced mouse models for PD. Our findings indicate that estrogen receptor activation plays a neuroprotective role and that rhododendrin could be a potential therapeutic agent in preventing PARP1-dependent dopaminergic cell loss in PD.

The Structure and Function of Estrogen Receptor β: Essential Roles in Gene Regulation

The Olathe North MSOE Center for BioMolecular Modeling SMART Team used 3‐D modeling and printing technology to examine the structure‐function relationships and regulatory roles of ERβ. Estrogens are steroid hormones synthesized from cholesterol in cells of the ovary and other tissues expressing the enzyme aromatase. These hormones are secreted into the bloodstream and modulate numerous physiological functions through gene regulation. To achieve this, estrogens pass through cell and nuclear membranes, facilitated by their lipophilic and miniscule nature. In target cells, estrogens bind to nuclear transcription factors called estrogen receptors (ERs), the two primary types being estrogen receptor alpha (ERα) and beta (ERβ). ERs typically form either homodimers with an identical molecule or heterodimers of ERα with ERβ. Estrogen binding occurs at ER's ligand binding domain (LBD), activating the ER's DNA binding domain (DBD). The ER dimer then binds to DNA at estrogen response elements (EREs) located in the promoter regions of estrogen‐responsive genes, allowing the ER to regulate the transcription of target genes. However, this process is only one of four mechanisms by which ERs function. In addition to this genomic mechanism, ERs can also function through tethered, nongenomic, and ligand‐independent mechanisms. In all these processes, ERs' role as a gene regulator is determined by the physical change in the structure of various ER domains, making it essential to analyze the ERs' protein structure. In this review, we focus on the structure and function of ERβ because of its largely unexplored physiological significance and clinical potential. ERβ is most highly expressed in the ovaries, mammary glands, prostate, testes, gastrointestinal tract, and immune system. Transcriptional regulation by ERβ is essential for ovarian follicle maturation and ovulation. Additionally, ERβ is involved in neurogenesis, vascular function modulation, cardiac myocyte maintenance, and metabolism regulation, among other physiological functions. In a pathological context, recent studies suggest ERβ is tumor suppressing while ERα increases tumor growth. Specifically, ERβ can inhibit proliferation while inducing differentiation and apoptosis in tumor cells. Thus, activation of ERβ by synthetic agonists, known as selective estrogen receptor modulators (SERM), has clinical significance concerning the treatment of breast, prostate, colon, and ovarian cancers. Here, we present a review of the latest research on ERβ in conjunction with its physical model, emphasizing ERβ's regulatory roles in human health.Support or Funding InformationThis is a SMART Team project supported through the contributions of Dr. M.A. Karim Rumi of the University of Kansas Medical Center, the Milwaukee School of Engineering, and the Olathe Medical Professions 21st Century Academy.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Estrogen receptor β upregulates CCL2 via NF-κB signaling in endometriotic stromal cells and recruits macrophages to promote the pathogenesis of endometriosis.

How is the activation of estrogen receptor β (ERβ) in endometriotic stromal cells (ESCs) involved in macrophage recruitment to promote the pathogenesis of endometriosis? ERβ modulates the production of C-C motif chemokine ligand 2 (CCL2) via nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling in ESCs and thus recruits macrophages to ectopic lesions to promote pathogenesis. Macrophages are mainly recruited to the peritoneal cavity to promote the pathogenesis of endometriosis. Recent studies have demonstrated that ERβ plays an important role in the progression of endometriosis through modulating apoptosis and inflammation. An observational study consisting of 22 cases (women with endometriosis, diagnosed by laparoscopy and histological analysis) and 14 controls (without endometriosis) was carried out. Tissues and stromal cells that were isolated from 22 patients with ovarian endometrioma and deeply infiltrating endometriosis were compared with tissues and stromal cells from 14 patients with normal cycling endometrium using immunohistochemistry, quantitative PCR, Western blot, cell migration assay and cloning formation assay. P values < 0.05 were considered significant, and experiments were repeated in at least three different cell preparations. We observed that accumulated macrophages were recruited to the ectopic milieu and mainly adopted an alternatively activated macrophage (M2) phenotype. To reveal the underlying mechanism for this, we conducted a series of experiments and found that high expression of ERβ led to the production of CCL2 via NF-κB signaling and macrophages were recruited to the ectopic milieu. An in vitro co-culture assay also suggested that the recruited macrophages in turn could promote the proliferation and clonogenic ability of ESCs. Overall, the activation of ERβ in ESCs is involved in macrophage recruitment via NF-κB/CCL2 signaling and subsequently appears to promote the pathogenesis of endometriosis. N/A. Due to the limitations of obtaining surgical specimens, endometrioma tissues were collected mainly from women diagnosed with middle to late stage endometriosis. We identified the predominant presence of M2 macrophages in the samples used in our study, but the underlying mechanism of how recruited macrophages acquire the M2 phenotype is undefined. This work provides novel insight into the mechanism by which ERβ may modulate macrophage infiltration and promote pathogenesis, which may provide a new therapeutic target for endometriosis. This study was supported by the National Natural Science Foundation of China (81671430). The authors have no conflicts of interest.

Abstract P5-05-03: Estrogen receptor beta elicits anti-cancer effects in triple negative breast cancer through suppression of NFκB signaling

Abstract Background: Triple Negative Breast Cancer (TNBC) affects approximately 15-20% of BC patients, yet accounts for a disproportionately higher rate of BC morbidity and mortality, in part due to lack of targeted therapies. Using well-validated antibodies, Estrogen Receptor Beta (ERβ) protein has been shown to be expressed in approximately 25% of TNBCs and is associated with improved patient outcomes. Using multiple ERβ +/- TNBC cell lines and PDX models, we have demonstrated that ligand-mediated activation of ERβ by estradiol (E2) decreases cell proliferation, invasion, and migration in vitro, as well as primary tumor growth and metastatic spread in vivo. Methods: To determine the mechanisms by which ERβ elicits these anti-cancer effects, we elucidated the ERβ transcriptome and cistrome via Microarray and ChIPseq, respectively, in TNBC cells stably expressing ERβ in a doxycycline-inducible manner. We also performed gene expression and luciferase assays to assess the impact of ERβ on NFκB signaling, followed by ChIP-PCR and ChIPseq to assess how ERβ modifies chromatin architecture near NFκB target genes. Results: Pathway analysis of ERβ-regulated genes identified NFκB signaling as one of the most suppressed pathways in response to E2 treatment. Indeed, numerous NFκB target genes were among the most down-regulated genes following E2 treatment but only in the presence of ERβ expression. Chromatin Immunoprecipitation followed by sequencing (ChIPseq) revealed that ERβ primarily associated with estrogen response elements (EREs), but was also enriched around NFκB binding sites following E2 treatment. In fact, 12% of all ERβ binding sites were enriched for NFκB response elements and ERβ was shown to physically associate with NFκB protein. Using an NFκB reporter construct and qPCR, ERβ was shown to block TNFα-mediated induction of NFκB signaling and NFκB target gene expression. Globally, RNAseq identified 200 genes to be significantly regulated by TNFα in TNBC cells, of which 81 were significantly altered in the presence of E2+TNFα. ChIPseq demonstrated that ligand-mediated activation of ERβ significantly diminished an activating histone mark (H3K27Ac) at many of these NFκB target genes while enhancing a repressive mark (H3K27Me3). These modifications are also associated with recruitment of the histone methyltransferase, EZH2, to enhancer elements of these NFκB target genes. Drug-mediated blockade of HDAC and EZH2 activity reversed suppression of NFκB target gene expression by ERβ. Conclusions: Our data suggest that ERβ may elicit its anti-cancer effects in part via formation of a novel co-repressor complex consisting of ERβ, NFκB, and EZH2. These data are in keeping with prior observations of the importance of NFκB signaling as it relates to TNBC cell proliferation and invasion, and that decreased expression of NFκB target genes is associated with improved outcomes in TNBC patients. Currently, a Mayo Breast SPORE prospective study is underway to investigate the role of estradiol in ERβ expressing TNBC and to further evaluate the cross-talk between ERβ and NFκB signaling in TNBC. Citation Format: Aspros K, Nelson A, Ye Z, Sun Z, Chernukhin I, Carroll J, Ingle J, Goetz M, Hawse J. Estrogen receptor beta elicits anti-cancer effects in triple negative breast cancer through suppression of NFκB signaling [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-05-03.

In vivo actions of Bisphenol F on the reproductive neuroendocrine system after long-term exposure in zebrafish

Although Bisphenol F (BPF), a bisphenol A (BPA) analogue with a similar chemical structure to that of BPA, is widely used in commercial products, little is known about its potential toxic effects on the reproductive neuroendocrine system in vivo. The present study aimed to comprehensively evaluate the effects of BPF on the reproductive neuroendocrine system in zebrafish and to assess the potential mechanisms underlying its association with estrogen receptor (ER) and aromatase (AROM) pathways. Long-term exposure to environmentally relevant and low levels of BPF led to increased expression of reproductive neuroendocrine-related genes (kiss1, kiss1r, gnrh3, lhβ, and fshβ) in the zebrafish brain, as well as increased levels of adrenocorticotropic, gonadotropin-releasing, luteinizing, and follicle-stimulating hormones in the zebrafish brain and vitellogenin in the zebrafish liver. In addition, these effects were associated with an increase in erα, erβ, cyp19a, and cyp19b activity. Meanwhile, ER and AROM antagonists, alone or in combination, significantly attenuated the stimulation of kiss1, lhβ, vtg, and gnrh3 expression, thereby suggesting that chronic BPF exposure affects the regulation of the reproductive neuroendocrine system through activation of the ER and AROM pathways. Moreover, since BPF and bisphenol S induced toxic and reproductive neuroendocrine effects similar to those of BPA, the current accepted usage of BPA and its analogs should be reconsidered in the future.

Estrogen receptor β plays a protective role in zearalenone-induced oxidative stress in normal prostate epithelial cells

Zearalenone (ZEA) - a fungal mycotoxin is reported to both cause the oxidative stress associated with death of cells as well as induction of the proliferation of cells, depending on its concentration and the type of cells. ZEA due to its structural similarity to naturally occurring estrogens is able to bind to estrogen receptors and triggers estrogen-associated signaling pathways. The aim of this study is to evaluate whether the induction of oxidative stress in normal epithelial prostate PNT1A cells is associated with estrogenic activity of ZEA. We observed that ZEA-induced oxidative stress in PNT1A cells is associated with a decrease in the oxidative stress defense enzymes expression, cell cycle arrest in G2/M cell cycle phase as well as the decreased migration of cells. The results also suggest that the observed effect might be associated with the nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB)- hypoxia inducible factor 1 alpha (HIF-1α) signaling pathway. The usage of estrogen receptor β (ERβ) selective antagonist 4-[2-phenyl-5,7-bis(trifluoromethyl)pyrazolo[1,5-a]pyrimidin-3-yl]-phenol PHTPP showed that ERβ activity is able to decrease the ZEA-induced oxidative stress, but is not enough to counteract it, indicating that ZEA-induced oxidative stress is only partially associated with estrogenic activity of ZEA.

The Role of Oestrogen Receptor Beta (ERβ) in the Aetiology and Treatment of Type 2 Diabetes Mellitus.

Challenges facing the treatment of type 2 diabetes necessitate the search for agents which act via alternative pathways to provide better therapeutic outcomes. Recently, an increasing body of evidence implicates the activation of oestrogen receptors (ERα and ERβ) in the development and treatment of underlying conditions in type 2 diabetes. This article summarizes available evidence for the involvement of oestrogen receptors in insulin secretion, insulin resistance as well as glucose uptake and highlights the potential of ERβ as a therapeutic target. Recent studies indicate an association between the activation of each of the isoforms of ER and recent findings indicate that ERβ shows promise as a potential target for antidiabetic drugs. In vitro and in vivo studies in receptor knockout mice indicate beneficial actions of selective agonists of ERβ receptor and underscore its therapeutic potential. Studies are needed to further elucidate the exact mechanism underlying the role of ERβ activation as a therapeutic approach in the management of type 2 diabetes.

Ginsenoside Rb1 Blocks Ritonavir-Induced Oxidative Stress and eNOS Downregulation through Activation of Estrogen Receptor-Beta and Upregulation of SOD in Human Endothelial Cells.

We have previously shown that ritonavir (RTV), a highly active anti-retroviral therapy (HAART) drug, can cause endothelial dysfunction through oxidative stress. Several antioxidants including ginsenoside Rb1, a compound with antioxidant effect, can effectively block this side effect of RTV in endothelial cells. In the current study, we explored a mechanism by which ginsenoside Rb1 could protect these cells via binding of estrogen receptors (ERs). We found that several human endothelial cell lines differentially expressed ER-β and had very low levels of ER-α. RTV treatment significantly increased the production of reactive oxygen species (ROS) and decreased the expression of endothelial nitric oxidase synthase (eNOS) and superoxide dismutase (SOD) in HUVECs, while Rb1 effectively blocked these effects of RTV. These effects of Rb1 were effectively inhibited by silencing ER-β, indicating that ginsenoside Rb1 requires ER-β for its antioxidant activity in inhibiting the deleterious effect of RTV in human endothelial cells. Furthermore, Rb1 specifically activated ER-β transactivation activity by ER-β luciferase reporter assay. Rb1 competitively bound to ER-β, which was determined by the high sensitive fluorescent polarization assay.

Oestradiol influences on dopamine release from the nucleus accumbens shell: sex differences and the role of selective oestradiol receptor subtypes.

Females are more sensitive than males to both the acute and prolonged effects of psychomotor stimulants. In females, this is regulated by oestradiol, which enhances dopamine release in the dorsal striatum. In this study, we tested the acute effect of oestradiol on dopamine release in the nucleus accumbens (NAc) shell after cocaine administration and investigated which oestradiol receptors (ERs) contribute to sex differences in the response to cocaine. The ability of oestradiol benzoate (EB) to acutely modulate the effect of cocaine on phasic dopamine release in the NAc shell was measured by fast-scan cyclic voltammetry in anaesthetized male and female rats. The roles of ER subtypes, ERα and ERβ, was determined with selective agonists. EB acutely enhanced the effect of cocaine on stimulated dopamine release from the NAc shell in females but not in male rats only at levels of stimulation expected to optimally saturate dopamine transporters. Enhanced dopamine release after cocaine administration was also observed in females after selective activation of ERβ but not ERα. EB attenuated the effect of cocaine on NAc shell dopamine reuptake in males but not in females. Oestradiol acutely and rapidly regulates dopamine release in females and dopamine reuptake in males. In females, oestradiol rapidly enhances the effect of cocaine on dopamine release, likely via activation of ERβ. The effect of oestradiol in males is not seen with selective receptor subtype activation, a topic deserving of further study. This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Pregnenolone as a potential candidate for hormone therapy for female reproductive disorders targeting ERβ.

Many steroid hormones such as estrogen (E2) bind to their receptors for the regulation of biological processes. Pregnenolone (P5) is the precursor form of almost all steroid hormones and is often used to treat skin disorders and neurological complications. However, the mechanism and physiological function of P5 in reproductive organs are not well established. In this study, we investigated the effects of P5 on activation and expression of E2 receptor (ER) in the uteri and ovaries. To study the mechanism of P5 directly, Ishikawa cells were transfected with E2 response element (ERE)-luciferase plasmid and isoforms of ER. ERE-luciferase activity induced by P5 was similar to that induced by E2, and P5 showed high activity for ERβ without any relevance to P5-metabolizing hormones such as progesterone (P4) and E2. In an animal study, immature female rats treated with P5 showed upregulation of ERα and downregulation of ERβ in the uteri, which is the main organ expressing ERα. In ERβ-expressing organ ovaries, estrogen receptor 1, estrogen receptor 2, and P4 receptor were all downregulated by P5 and E2. Also, a decrease of ovarian cell proliferation and viability was observed in response to P5 relative to the control, suggesting that P5 may be a candidate for antiproliferative hormone of ovarian cancer. These findings suggest that P5 stimulates ERE promoter by ERβ-mediated signaling in the uteri and ovaries. Activation of ERβ by P5 may help in understanding the mechanism of ER-related female reproductive diseases such as endometriosis and ovarian cancer.

ERβ activation in obesity improves whole body metabolism via adipose tissue function and enhanced mitochondria biogenesis

ObjectiveEstrogens play a key role in the distribution of adipose tissue and have their action by binding to both estrogen receptors (ER), α and β. Although ERβ has a role in the energy metabolism, limited data of the physiological mechanism and metabolic response involved in the pharmacological activation of ERβ is available. MethodsFor clinical relevance, non-ovariectomized female mice were subjected to high fat diet together with pharmacological (DIP - 4-(2-(3,5-dimethylisoxazol-4-yl)-1H-indol-3-yl)phenol) interventions to ERβ selective activation. The physiological mechanism was assessed in vivo by magnetic resonance imaging and spectroscopy, and oral glucose and intraperitoneal insulin tolerance test before and after DIP treatment. Liver and adipose tissue metabolic response was measured in HFD + vehicle and HFD + DIP by stable isotope, RNA sequencing and protein content. ResultsHFD-fed females treated with DIP had a tissue-specific response towards ERβ selective activation. The metabolic profile showed an improved fasting glucose level, insulin sensitivity and reduced liver steatosis. ConclusionsOur data demonstrate that selective activation of ERβ exerts a tissue-specific activity which promotes a beneficial effect on whole body metabolic response to obesity.

ERβ-mediated induction of cystatins results in suppression of TGFβ signaling and inhibition of triple-negative breast cancer metastasis

Triple-negative breast cancer (TNBC) accounts for a disproportionately high number of deaths due to a lack of targeted therapies and an increased likelihood of distant recurrence. Estrogen receptor beta (ERβ), a well-characterized tumor suppressor, is expressed in 30% of TNBCs, and its expression is associated with improved patient outcomes. We demonstrate that therapeutic activation of ERβ elicits potent anticancer effects in TNBC through the induction of a family of secreted proteins known as the cystatins, which function to inhibit canonical TGFβ signaling and suppress metastatic phenotypes both in vitro and in vivo. These data reveal the involvement of cystatins in suppressing breast cancer progression and highlight the value of ERβ-targeted therapies for the treatment of TNBC patients.

ERα and/or ERβ activation ameliorates cognitive impairment, neurogenesis and apoptosis in type 2 diabetes mellitus mice

Estrogen receptors (ERs) are thought to be associated with the onset and progression of neurodegenerative injuries and diseases, but the relationship and mechanisms underlying between ERs and cognition in type 2 diabetes remain elusive. In the current study, we investigated the effects of ERα and ERβ on the cognition, neurogenesis and apoptosis in high-fat diet and streptozocin-induced diabetic mice. We found that ERα and/or ERβ activation using their agonists (0.5 mg/kg E2, PPT or DPN) ameliorate memory impairment in the Morris water maze and Y-maze tests, increase hippocampal neurogenesis and prevent hippocampal apoptotic responses. Importantly, treatment with the pharmacologic ERs agonists caused significant increases in the membrane ERα and ERβ expression and subsequent PI3K/Akt, CREB and BDNF activation in the hippocampus of type 2 diabetes mellitus mice. Our data indicate that ERα and ERβ are involved in the cognitive impairment in type 2 diabetes, and that activated ERs, such as application of ERs agonists, could be a novel and promising strategy for the treatment of diabetic cognitive impairment.

Endometrial attachment and invasion is decreased with estrogen receptor beta knock down

Endometriosis requires estrogen for development and growth. Levels of estrogen receptor beta (ERβ) in endometriosis are reported to be 100 times higher than normal endometrial tissue and inhibition of ERβ activity by an ERβ selective antagonist suppresses endometriotic lesion growth in mice.1,2 Here, we assessed the role of ERβ in the development of the early endometriotic lesion by examining the effect of ERβ knock down on endometrial stromal cell (ESC) cell attachment and invasion. In vitro study. ERβ was knocked-down (ERβKD) with lipofectamine using shRNA in an immortalized human ESC line (tHESC). Western blot and densitometric analysis were used to assess protein expression. Established in vitro assays were used to assess WT and ERβKD tHESC attachment to peritoneal mesothelial cells (PMCs) and invasion through a monolayer of PMCs. Results were analyzed with unpaired t-tests. tHESCs with ERβKD demonstrated decreased protein expression by Western blot and densitometric analysis. ERβKD attachment to PMCs decreased in comparison to WT (42% vs 67%, respectively; p<0.001). ERβKD invasion through PMCs decreased in ERβKD compared to WT (264 ±16 vs 404 ± 22, respectively; p<0.005). ERβKD decreases tHESCs adhesion to and invasion through PMCs. ERβ may serve as a future therapeutic target to decrease early endometriotic lesion formation.

17β-Estradiol/extrogen receptor β alleviates apoptosis and enhances matrix biosynthesis of nucleus pulposus cells through regulating oxidative damage under a high glucose condition

BackgroundHyperglycemia in the Diabetes mellitus (DM) patients is a potential etiology of disc degeneration. 17β-estradiol (17β-E2) supplementation plays an anti-diabetic role in DM patients. ObjectiveThis study was aimed to investigate the role and mechanism of 17β-E2 in regulating nucleus pulposus (NP) cell apoptosis and NP matrix production under a high glucose condition. MethodsRat NP cells were cultured in medium with a high glucose concentration (0.2 M). 17β-E2 was added into the culture medium to investigate its protective effects. The ERβ inhibitor PHTPP and ERβ activator ERB041 were used to investigate the effects of ERβ. NP cell apoptosis was analyzed by flow cytometry and expression of apoptosis-related molecules. NP matrix production was evaluated by expression of matrix macromolecules. Additionally, intracellular reactive oxygen species (ROS) content was also detected. ResultsCompared with the control NP cells, 17β-E2 decreased NP cell apoptosis ratio, down-regulated gene expression of Bax and caspase-3, up-regulated gene expression of Bcl-2, increased protein expression of cleaved PARP and cleaved caspase-3, and increased expression of matrix molecules (aggrecan and collagen II). Moreover, 17β-E2 decreased ROS content. Further analysis showed that ERβ inhibition partly reversed these effects of 17β-E2 whereas ERβ activation further promoted its effects. Conclusion17β-E2/ERβ interaction attenuates apoptosis and promotes matrix biosynthesis of NP cells through alleviating oxidative damage under a high glucose condition. This study provides new knowledge on strategies for retarding disc degeneration.

Activation of ERα and/or ERβ ameliorates cognitive impairment and apoptosis in streptozotocin-induced diabetic mice

Estrogen receptors (ERs) are thought to be associated with the onset and progression of neurodegenerative injuries and diseases, but the relationship and mechanisms underlying between ERs and cognition in type 1 diabetes remain elusive. In the current study, we investigated the effects of ERα and ERβ on the memory impairment and apoptosis in streptozotocin-induced diabetic mice. We found that ERα and/or ERβ activation using their agonists (0.5 mg/kg E2, PPT or DPN) ameliorate memory impairment in the Morris water maze (MWM) and Y-maze tests and suppress apoptosis as evidenced by decreased caspase-3 activity and increased ratio of Bcl-2/Bax. Importantly, treatment with the pharmacologic ERs agonists caused significant increases in the membrane ERα and ERβ expression and subsequent PI3K/Akt, CREB and BDNF activation in the hippocampus of diabetic mice. Our data indicate that ERα and ERβ are involved in the cognitive impairment of type 1 diabetes and that activation of ERs via administration of ERs agonists could be a novel and promising strategy for the treatment of diabetic cognitive impairment.