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Sample records for estrogen receptor beta

  1. Cancer therapy using natural ligands that target estrogen receptor beta

    PubMed Central

    Sareddy, Gangadhara R; Vadlamudi, Ratna K.

    2016-01-01

    Estrogen receptor beta (ERβ) is one of the two key receptors (ERα, ERβ) that facilitate biological actions of 17β-estradiol (E2). ERβ is widely expressed in many tissues, and its expression is reduced or lost during progression of many tumors. ERβ facilitates estrogen signaling by both genomic (classical and non-classical) and extra-nuclear signaling. Emerging evidence suggests that ERβ functions as a tissue-specific tumor suppressor with anti-proliferative actions. Recent studies have identified a number of naturally available selective ERβ agonists. Targeting ERβ using its naturally available ligands is an attractive approach for treating and preventing cancers. This review presents the beneficial actions of ERβ signaling and clinical utility of several natural ERβ ligands as potential cancer therapy. PMID:26614454

  2. Both estrogen receptor alpha and estrogen receptor beta agonists enhance cell proliferation in the dentate gyrus of adult female rats.

    PubMed

    Mazzucco, C A; Lieblich, S E; Bingham, B I; Williamson, M A; Viau, V; Galea, L A M

    2006-09-15

    This study investigated the involvement of estrogen receptors alpha and beta in estradiol-induced enhancement of hippocampal neurogenesis in the adult female rat. Subtype selective estrogen receptor agonists, propyl-pyrazole triol (estrogen receptor alpha agonist) and diarylpropionitrile (estrogen receptor beta agonist) were examined for each receptor's contribution, individual and cooperative, for estradiol-enhanced hippocampal cell proliferation. Estradiol increases hippocampal cell proliferation within 4 h [Ormerod BK, Lee TT, Galea LA (2003) Estradiol initially enhances but subsequently suppresses (via adrenal steroids) granule cell proliferation in the dentate gyrus of adult female rats. J Neurobiol 55:247-260]. Therefore, animals received s.c. injections of estradiol (10 microg), propyl-pyrazole triol and diarylpropionitrile alone (1.25, 2.5, 5.0 mg/0.1 ml dimethylsulfoxide) or in combination (2.5 mg propyl-pyrazole triol+2.5 mg diarylpropionitrile/0.1 ml dimethylsulfoxide) and 4 h later received an i.p. injection of the cell synthesis marker, bromodeoxyuridine (200 mg/kg). Diarylpropionitrile enhanced cell proliferation at all three administered doses (1.25 mg, P<0.008; 2.5 mg, P<0.003; 5 mg, P<0.005), whereas propyl-pyrazole triol significantly increased cell proliferation (P<0.0002) only at the dose of 2.5 mg. Our results demonstrate both estrogen receptor alpha and estrogen receptor beta are individually involved in estradiol-enhanced cell proliferation. Furthermore both estrogen receptor alpha and estrogen receptor beta mRNA was found co-localized with Ki-67 expression in the hippocampus albeit at low levels, indicating a potential direct influence of each receptor subtype on progenitor cells and their progeny. Dual receptor activation resulted in reduced levels of cell proliferation, supporting previous studies suggesting that estrogen receptor alpha and estrogen receptor beta may modulate each other's activity. Our results also suggest that a component

  3. Estrogen receptor beta as target for colorectal cancer prevention.

    PubMed

    Williams, Cecilia; DiLeo, Alfredo; Niv, Yaron; Gustafsson, Jan-Åke

    2016-03-01

    Colorectal cancer (CRC) is a leading cause of death in the United States. Despite its slow development and the capacity for early diagnosis, current preventive approaches are not sufficient. However, a role for estrogen has been demonstrated in multiple epidemiologic studies, which may benefit CRC prevention. A large body of evidence from preclinical studies indicates that expression of the estrogen receptor beta (ERβ/ESR2) demonstrates an inverse relationship with the presence of colorectal polyps and stage of tumors, and can mediate a protective response. Natural compounds, including phytoestrogens, or synthetic ERβ selective agonists, can activate or upregulate ERβ in the colon and promote apoptosis in preclinical models and in clinical experience. Importantly, this activity has been associated with a reduction in polyp formation and, in rodent models of CRC, has been shown to lower incidence of colon adenocarcinoma. Collectively, these findings indicate that targeted activation of ERβ may represent a novel clinical approach for management of colorectal adenomatous polyps and prevention of colorectal carcinoma in patients at risk for this condition. In this review, we discuss the potential of new chemopreventive or dietary approaches based on estrogen signaling.

  4. Estrogen receptor-beta, estrogen receptor-alpha, and progesterone resistance in endometriosis.

    PubMed

    Bulun, Serdar E; Cheng, You-Hong; Pavone, Mary Ellen; Xue, Qing; Attar, Erkut; Trukhacheva, Elena; Tokunaga, Hideki; Utsunomiya, Hiroki; Yin, Ping; Luo, Xia; Lin, Zhihong; Imir, Gonca; Thung, Stephen; Su, Emily J; Kim, J Julie

    2010-01-01

    Loss of progesterone signaling in the endometrium may be a causal factor in the development of endometriosis, and progesterone resistance is commonly observed in women with this disease. In endometriotic stromal cells, the levels of progesterone receptor (PR), particularly the PR-B isoform, are significantly decreased, leading to a loss of paracrine signaling. PR deficiency likely underlies the development of progesterone resistance in women with endometriosis who no longer respond to progestin therapy. Here we review the complex epigenetic and transcriptional mechanisms leading to PR deficiency. The initial event may involve deficient methylation of the estrogen receptor (ER)beta promoter resulting in pathologic overexpression of ERbeta in endometriotic stromal cells. We speculate that alterations in the relative levels of ERbeta and ERalpha in endometrial tissue dictate E2-regulated PR expression, such that a decreased ERalpha-tauomicron-ERbeta ratio may result in suppression of PR. In this review, we propose a molecular model that may be responsible for changes in ERbeta and ERalpha leading to PR loss and progesterone resistance in endometriosis.

  5. Estrogen receptor transcription and transactivation: Estrogen receptor alpha and estrogen receptor beta - regulation by selective estrogen receptor modulators and importance in breast cancer

    PubMed Central

    S Katzenellenbogen, Benita; A Katzenellenbogen, John

    2000-01-01

    Estrogens display intriguing tissue-selective action that is of great biomedical importance in the development of optimal therapeutics for the prevention and treatment of breast cancer, for menopausal hormone replacement, and for fertility regulation. Certain compounds that act through the estrogen receptor (ER), now referred to as selective estrogen receptor modulators (SERMs), can demonstrate remarkable differences in activity in the various estrogen target tissues, functioning as agonists in some tissues but as antagonists in others. Recent advances elucidating the tripartite nature of the biochemical and molecular actions of estrogens provide a good basis for understanding these tissue-selective actions. As discussed in this thematic review, the development of optimal SERMs should now be viewed in the context of two estrogen receptor subtypes, ERα and ERβ, that have differing affinities and responsiveness to various SERMs, and differing tissue distribution and effectiveness at various gene regulatory sites. Cellular, biochemical, and structural approaches have also shown that the nature of the ligand affects the conformation assumed by the ER-ligand complex, thereby regulating its state of phosphorylation and the recruitment of different coregulator proteins. Growth factors and protein kinases that control the phosphorylation state of the complex also regulate the bioactivity of the ER. These interactions and changes determine the magnitude of the transcriptional response and the potency of different SERMs. As these critical components are becoming increasingly well defined, they provide a sound basis for the development of novel SERMs with optimal profiles of tissue selectivity as medical therapeutic agents. PMID:11250726

  6. Modulation of estrogen receptor-beta isoforms by phytoestrogens in breast cancer cells.

    PubMed

    Cappelletti, Vera; Miodini, Patrizia; Di Fronzo, Giovanni; Daidone, Maria Grazia

    2006-05-01

    High consumption of phytoestrogen-rich food correlates with reduced incidence of breast cancer. However, the effect of phytoestrogens on growth of pre-existing breast tumors presents concerns when planning the use of phytoestrogens as chemoprevention st rategy. Genistein, the active phytoestrogen in soy, displays weak estrogenic activity mediated by estrogen receptor (ER) with a preferential binding for the ER-beta species. However, no information is at present available on the interaction between phytoestrogens and the various isoforms generated by alternative splicing. In two human breast cancer cell lines, T47D and BT20, which express variable levels of ER-beta, the effect of genistein and quercetin was evaluated singly and in comparison with 17beta-estradiol, on mRNA expression of estrogen receptor-beta (ER-beta) isoforms evaluated by a triple primer RT-PCR assay. In T47D cells estradiol caused a 6-fold up-regulation of total ER-beta, and modified the relative expression pattern of the various isoforms, up-regulating the beta2 and down-regulating the beta5 isoform. Genistein up-regulated ER-beta2 and ER-beta1 in T47D cells, and after treatment the ER-beta2 isoform became prevalent, while in BT20 cells it almost doubled the percent contribution of ER-beta1 and ER-beta2 to total ER-beta. Quercetin did not alter the total levels nor the percent distribution of ER-beta isoforms in either cell line. Genistein, through the modulation of ER-beta isoform RNA expression inhibited estrogen-promoted cell growth, without interfering on estrogen-regulated transcription. ER-beta and its ER-beta mRNA isoforms may be involved in a self-limiting mechanism of estrogenic stimulation promoted either by the natural hormone or by weaker estrogen agonists like genistein.

  7. Estradiol-induced modulation of estrogen receptor-beta and GABA within the adult neocortex: a potential transsynaptic mechanism for estrogen modulation of BDNF.

    PubMed

    Blurton-Jones, Mathew; Tuszynski, Mark H

    2006-12-01

    Estrogen influences brain-derived neurotrophic factor (BDNF) expression in the neocortex. However, BDNF-producing cortical neurons do not express detectable levels of nuclear estrogen receptors; instead, the most abundant cortical nuclear estrogen receptor, ER-beta, is present in GABAergic neurons, prompting us to test the hypothesis that estrogen effects on BDNF are mediated via cortical inhibitory interneurons. Adult female ovariectomized rats were provided acute estrogen replacement and the number of cortical GABA, ER-beta, and ER-beta/GABA double-labeled neurons was examined. Within 48 hours of injection of 17-beta-estradiol, the number of perirhinal neurons double-labeled for ER-beta/GABA was reduced by 28% (P<0.01 compared to vehicle-treated ovariectomized controls), and all cells expressing detectable levels of GABA were reduced by 19% (P<0.01). To investigate potential relationships between estrogen receptors, GABAergic neurons, and BDNF-expressing cells, brain sections were double- or triple-labeled for ER-beta, GABAergic, and BDNF immunomarkers. The findings indicated that ER-beta-bearing inhibitory neurons project onto other GABAergic neurons that lack nuclear estrogen receptors; these inhibitory neurons in turn innervate BDNF-expressing excitatory cells. High estrogen states reduce cortical GABA levels, presumably releasing inhibition on BDNF-expressing neurons. This identifies a putative two-step transsynaptic mechanism whereby estrogen availability modulates expression of inhibitory transmitters, resulting in increased BDNF expression.

  8. Rapid yeast estrogen bioassays stably expressing human estrogen receptors alpha and beta, and green fluorescent protein: a comparison of different compounds with both receptor types.

    PubMed

    Bovee, Toine F H; Helsdingen, Richard J R; Rietjens, Ivonne M C M; Keijer, Jaap; Hoogenboom, Ron L A P

    2004-07-01

    Previously, we described the construction of a rapid yeast bioassay stably expressing human estrogen receptor (hERalpha) and yeast enhanced green fluorescent protein (yEGFP) in response to estrogens. In the present study, the properties of this assay were further studied by testing a series of estrogenic compounds. Furthermore, a similar assay was developed based on the stable expression of human estrogen receptor beta (hERbeta). When exposed to 17beta-estradiol, the maximum transcriptional activity of the ERbeta cytosensor was only about 40% of the activity observed with ERalpha, but the concentration where half-maximal activation is reached (EC50), was about five times lower. The relative estrogenic potencies (REP), defined as the ratio between the EC50 of 17beta-estradiol and the EC50 of the compound, of the synthetic hormones dienestrol, hexestrol and especially mestranol were higher with ER, while DES was slightly more potent with ERbeta. The gestagens progesterone and medroxyprogesterone-acetate showed no response, whereas the androgen testosterone showed a very weak response. The anabolic agent, 19-nortestosterone showed a clear dose-related response with estrogen receptor but not beta. The phytoestrogens coumestrol, genistein, genistin, daidzein, daidzin and naringenin were relatively more potent with ERbeta. Ranking of the estrogenic potency with ER was: 17beta-estradiol > 8-prenylnaringenin > coumestrol > zearalenone > genistein > genistin > naringenin. The ranking with the ERbeta was: 17beta-estradiol > coumestrol > genistein > zearalenone > 8-prenylnaringen > daidzein > naringenin > genistin > daidzin. The hop estrogen 8-prenylnaringenin is relatively more potent with ERalpha. These data show that the newly developed bioassays are valuable tools for the rapid and high-throughput screening for estrogenic activity.

  9. beta-estradiol influences differentiation of hippocampal neurons in vitro through an estrogen receptor-mediated process.

    PubMed

    Audesirk, T; Cabell, L; Kern, M; Audesirk, G

    2003-01-01

    We utilized morphometric analysis of 3 day cultures of hippocampal neurons to determine the effects of both estradiol and the synthetic estrogen receptor modulator raloxifene on several parameters of neuronal growth and differentiation. These measurements included survival, neurite production, dendrite number, and axon and dendrite length and branching. 17 beta-Estradiol (10 nM) selectively stimulated dendrite branching; this effect was neither mimicked by alpha-estradiol, nor blocked by the estrogen receptor antagonist ICI 182780. The selective estrogen receptor modulator raloxifene (100 nM) neither mimicked nor reversed the effects of estradiol on dendritic branching. Western immunoblotting for the alpha and beta subtypes of estrogen receptor revealed the presence of alpha, but not beta, estrogen receptors in our hippocampal cultures. There is growing recognition of the effects of 17 beta-estradiol on neuronal development and physiology, with implications for brain sexual dimorphism, plasticity, cognition, and the maintenance of cognitive function during aging. The role of estradiol in hippocampal neuronal differentiation and function has particular implications for learning and memory. These data support the hypothesis that 17 beta-estradiol is acting via alpha estrogen receptors in influencing hippocampal development in vitro. Raloxifene, prescribed to combat osteoporosis in post-menopausal women, is a selective estrogen receptor modulator with tissue-specific agonist/antagonist properties. Because raloxifene had no effect on dendritic branching, we hypothesize that it does not interact with the alpha estrogen receptor in this experimental paradigm.

  10. Estrogenic activity and estrogen receptor beta binding of the UV filter 3-benzylidene camphor. Comparison with 4-methylbenzylidene camphor.

    PubMed

    Schlumpf, Margret; Jarry, Hubert; Wuttke, Wolfgang; Ma, Risheng; Lichtensteiger, Walter

    2004-07-01

    UV filters represent new classes of estrogenic [Environ. Health Perspect. 109 (2001) 239] or antiandrogenic [Toxicol. Sci. 74 (2003) 43] chemicals. We tested 3-benzylidene camphor (3-BC), reported as estrogenic in fish [Pharmacol. Toxicol. 91 (2002) 204], and mammalian systems in comparison to 4-methylbenzylidene camphor (4-MBC), shown to be active in rats, and analyzed binding to estrogen receptor subtypes. 3-BC and 4-MBC stimulated MCF-7 cell proliferation (EC(50): 0.68 and 3.9 microM). The uterotrophic assay of 3-BC (oral gavage) in immature rats showed unexpected potency with ED50 45.3mg/kg per day; lowest effective dose 2mg/kg per day, and maximum effect with 70% of ethinylestradiol. After comparing with literature data, we found that the oral 3-BC was considerably more potent than oral bisphenol A and almost as active as subcutaneous genistein. 3-BC and 4-MBC displaced 16alpha 125I-estradiol from porcine uterine cytosolic receptors (IC(50): 14.5 and 112 microM), and from recombinant human estrogen receptor beta (hERbeta) (IC(50): 3-BC, 11.8 microM; 4-MBC, 35.3 microM), whereas no displacement was detected at human estrogen receptor alpha (hERalpha) up to 3mM. This subtype selectivity makes the two camphor derivatives interesting model compounds. Their activity on immature rat uterus is not easily explained by ERbeta activation. It cannot be excluded that active metabolites with possibly different receptor binding characteristics are formed in vivo.

  11. Phytoestrogens induce differential estrogen receptor alpha- or Beta-mediated responses in transfected breast cancer cells.

    PubMed

    Harris, D M; Besselink, E; Henning, S M; Go, V L W; Heber, D

    2005-09-01

    Increased intake of phytoestrogens may be associated with a lower risk of cancer in the breast and several other sites, although there is controversy surrounding this activity. One of the mechanisms proposed to explain the activity of phytoestrogens is their ability to bind and activate human estrogen receptor alpha (ERalpha) and human estrogen receptor beta (ERbeta). Nine phytoestrogens were tested for their ability to transactivate ERalpha or ERbeta at a range of doses. Mammary adenocarcinoma (MCF-7) cells were co-transfected with either ERalpha or ERbeta, and an estrogen-response element was linked to a luciferase reporter gene. Dose-dependent responses were compared with the endogenous ligand 17beta-estradiol. Purified genistein, daidzein, apigenin, and coumestrol showed differential and robust transactivation of ERalpha- and ERbeta-induced transcription, with an up to 100-fold stronger activation of ERbeta. Equol, naringenin, and kaempferol were weaker agonists. When activity was evaluated against a background of 0.5 nM 17beta-estradiol, the addition of genistein, daidzein, and resveratrol superstimulated the system, while kaempferol and quercetin were antagonists at the highest doses. This transfection assay provides an excellent model to evaluate the activation of ERalpha and ERbeta by different phytoestrogens in a breast cancer context and can be used as a screening bioassay tool to evaluate the estrogenic activity of extracts of herbs and foods.

  12. Understanding the selectivity of genistein for human estrogen receptor-beta using X-ray crystallography and computational methods.

    PubMed

    Manas, Eric S; Xu, Zhang B; Unwalla, Rayomand J; Somers, William S

    2004-12-01

    We present X-ray crystallographic and molecular modeling studies of estrogen receptors-alpha and -beta complexed with the estrogen receptor-beta-selective phytoestrogen genistein, and coactivator-derived NR box peptides containing an LXXLL motif. We demonstrate that the ligand binding mode is essentially identical when genistein is bound to both isoforms, despite the considerably weaker affinity of this ligand for estrogen receptor-alpha. In addition, we examine subtle differences between binding site residues, providing an explanation for why genistein is modestly selective for the beta isoform. To this end, we also present the results of quantum chemical studies and thermodynamic arguments that yield insight to the nature of the interactions leading to estrogen receptor-beta selectivity. The importance of our analysis to structure-based drug design is discussed.

  13. Repression of estrogen receptor {beta} function by putative tumor suppressor DBC1

    SciTech Connect

    Koyama, Satoshi; Wada-Hiraike, Osamu; Nakagawa, Shunsuke; Tanikawa, Michihiro; Hiraike, Haruko; Miyamoto, Yuichiro; Sone, Kenbun; Oda, Katsutoshi; Fukuhara, Hiroshi; Nakagawa, Keiichi; Kato, Shigeaki; Yano, Tetsu; Taketani, Yuji

    2010-02-12

    It has been well established that estrogen is involved in the pathophysiology of breast cancer. Estrogen receptor (ER) {alpha} appears to promote the proliferation of cancer tissues, while ER{beta} can protect against the mitogenic effect of estrogen in breast tissue. The expression status of ER{alpha} and ER{beta} may greatly influence on the development, treatment, and prognosis of breast cancer. Previous studies have indicated that the deleted in breast cancer 1 (DBC1/KIAA1967) gene product has roles in regulating functions of nuclear receptors. The gene encoding DBC1 is a candidate for tumor suppressor identified by genetic search for breast cancer. Caspase-dependent processing of DBC1 promotes apoptosis, and depletion of the endogenous DBC1 negatively regulates p53-dependent apoptosis through its specific inhibition of SIRT1. In addition, DBC1 modulates ER{alpha} expression and promotes breast cancer cell survival by binding to ER{alpha}. Here we report an ER{beta}-specific repressive function of DBC1. Immunoprecipitation and immunofluorescence studies show that ER{beta} and DBC1 interact in a ligand-independent manner similar to ER{alpha}. In vitro pull-down assays revealed a direct interaction between DBC1 amino-terminus and activation function-1/2 domain of ER{beta}. Although DBC1 shows no influence on the ligand-dependent transcriptional activation function of ER{alpha}, the expression of DBC1 negatively regulates the ligand-dependent transcriptional activation function of ER{beta}in vivo, and RNA interference-mediated depletion of DBC1 stimulates the transactivation function of ER{beta}. These results implicate the principal role of DBC1 in regulating ER{beta}-dependent gene expressions.

  14. Overexpression of estrogen receptor beta alleviates the toxic effects of beta-amyloid protein on PC12 cells via non-hormonal ligands☆

    PubMed Central

    Wang, Hui; Si, Lihui; Li, Xiaoxi; Deng, Weiguo; Yang, Haimiao; Yang, Yuyan; Fu, Yan

    2012-01-01

    After binding to the estrogen receptor, estrogen can alleviate the toxic effects of beta-amyloid protein, and thereby exert a therapeutic effect on Alzheimer's disease patients. Estrogen can increase the incidence of breast carcinoma and endometrial cancer in post-menopausal women, so it is not suitable for clinical treatment of Alzheimer's disease. There is recent evidence that the estrogen receptor can exert its neuroprotective effects without estrogen dependence. Real-time quantitative PCR and flow cytometry results showed that, compared with non-transfected PC12 cells, adenovirus-mediated estrogen receptor β gene-transfected PC12 cells exhibited lower expression of tumor necrosis factor α and interleukin 1β under stimulation with beta-amyloid protein and stronger protection from apoptosis. The Akt-specific inhibitor Abi-2 decreased the anti-inflammatory and anti-apoptotic effects of estrogen receptor β gene-transfection. These findings suggest that overexpression of estrogen receptor β can alleviate the toxic effect of beta-amyloid protein on PC12 cells, without estrogen dependence. The Akt pathway is one of the potential means for the anti-inflammatory and anti-apoptotic effects of the estrogen receptor. PMID:25722700

  15. Immunolocalization of androgen receptor, aromatase cytochrome P450, estrogen receptor alpha and estrogen receptor beta proteins during the breeding season in scent glands of muskrats (Ondatra zibethicus).

    PubMed

    Lu, Lu; Zhang, Haolin; Lv, Na; Ma, Xiaoting; Tian, Long; Hu, Xiao; Liu, Shuqiang; Xu, Meiyu; Weng, Qiang; Watanabe, Gen; Taya, Kazuyoshi

    2011-10-01

    Aromatase cytochrome P450 (P450arom) is an enzyme that catalyzes the conversion of androgen to estrogen. Expression of P450arom in extra-gonadal sites and locally-synthesized estrogen play an important role in physiological conditions. The purpose of this study was to investigate the cellular immunolocalization of androgen receptor (AR), P450arom, estrogen receptor alpha (ERa) and estrogen receptor beta (ERβ) in muskrat scent glands during the breeding season. Histological observation and immunohistochemistry of AR, P450arom, ERa and ERβ were performed in the muskrat scent glands. In addition, total proteins were extracted from scent glandular tissues in the breeding season and were used for Western blotting analysis for AR, P450arom, ERα and ERβ. Histologically, glandular cells, interstitial cells, epithelial cells of the excretory duct and the excretory tubules were identified in the muskrat scent glands during the breeding season. AR was only observed in glandular cells of scent glands; P450arom was expressed in glandular cells and epithelial cells of the excretory duct; ERα was found in glandular cells, interstitial cells and epithelial cells of the excretory duct, whereas ERβ was present in glandular cells and epithelial cells of the excretory duct. Also, the positive signals of AR, P450arom, ERα and ERβ by Western blotting were all observed in scent glandular tissues. These results suggested that the scent gland is the target organ of androgens and estrogens, and that estrogens may play an important autocrine or paracrine role in glandular function of the muskrats.

  16. Estrogen Receptors Alpha (ERα) and Beta (ERβ): Subtype-Selective Ligands and Clinical Potential

    PubMed Central

    Paterni, Ilaria; Granchi, Carlotta; Katzenellenbogen, John A.; Minutolo, Filippo

    2014-01-01

    Estrogen receptors alpha (ERα) and beta (ERβ) are nuclear transcription factors that are involved in the regulation of many complex physiological processes in humans. Modulation of these receptors by prospective therapeutic agents is currently being considered for prevention and treatment of a wide variety of pathological conditions, such as, cancer, metabolic and cardiovascular diseases, neurodegeneration, inflammation, and osteoporosis. This review provides an overview and update of compounds that have been recently reported as modulators of ERs, with a particular focus on their potential clinical applications. PMID:24971815

  17. Structure-based design of estrogen receptor-beta selective ligands.

    PubMed

    Manas, Eric S; Unwalla, Rayomand J; Xu, Zhang B; Malamas, Michael S; Miller, Chris P; Harris, Heather A; Hsiao, Chulai; Akopian, Tatos; Hum, Wah-Tung; Malakian, Karl; Wolfrom, Scott; Bapat, Ashok; Bhat, Ramesh A; Stahl, Mark L; Somers, William S; Alvarez, Juan C

    2004-11-24

    We present the structure-based optimization of a series of estrogen receptor-beta (ERbeta) selective ligands. X-ray cocrystal structures of these ligands complexed to both ERalpha and ERbeta are described. We also discuss how molecular modeling was used to take advantage of subtle differences between the two binding cavities in order to optimize selectivity for ERbeta over ERalpha. Quantum chemical calculations are utilized to gain insight into the mechanism of selectivity enhancement. Despite only two relatively conservative residue substitutions in the ligand binding pocket, the most selective compounds have greater than 100-fold selectivity for ERbeta relative to ERalpha when measured using a competitive radioligand binding assay.

  18. Estrogen Receptor beta mediates decreased occlusal loading induced inhibition of chondrocyte maturation in female mice

    PubMed Central

    Polur, Ilona; Kamiya, Yosuke; Xu, Manshan; Cabri, Bianca S.; Alshabeeb, Marwa; Wadhwa, Sunil; Chen, Jing

    2015-01-01

    Objective Temporomandibular joint (TMJ) disorders predominantly afflict women, suggesting that estrogen may play a role in the disease process. Defects in mechanical loading-induced TMJ remodeling are believed to be a major etiological factor in TMJ degenerative disease. Previously, we found that, decreased occlusal loading caused a significant decrease in early chondrocyte maturation markers (Sox9 and Col 2) in female, but not male, C57BL/6 wild type mice (1). The goal of this study was to examine the role of Estrogen Receptor (ER) beta in mediating these effects. Design 21-day-old male (n=24) and female (n=25) ER beta KO mice were exposed to decreased occlusal loading (soft diet administration and incisor trimming) for 4 weeks. At 49 days of age the mice were sacrificed. Proliferation, gene expression, Col 2 immunohistochemistry and micro-CT analysis were performed on the mandibular condyles. Results Decreased occlusal loading triggered similar effects in male and female ER beta KO mice; specifically, significant decreases in Col 10 expression, subchondral total volume, bone volume, and trabecular number. Conclusion Decreased occlusal loading induced inhibition of chondrocyte maturation markers (Sox9 and Col 2) did not occur in female ER beta deficient mice. PMID:25791327

  19. The androgen derivative 5alpha-androstane-3beta,17beta-diol inhibits prostate cancer cell migration through activation of the estrogen receptor beta subtype.

    PubMed

    Guerini, Vittoria; Sau, Daniela; Scaccianoce, Eugenia; Rusmini, Paola; Ciana, Paolo; Maggi, Adriana; Martini, Paolo G V; Katzenellenbogen, Benita S; Martini, Luciano; Motta, Marcella; Poletti, Angelo

    2005-06-15

    Prostate cancer growth depends, in its earlier stages, on androgens and is usually pharmacologically modulated with androgen blockade. However, androgen-ablation therapy may generate androgen-independent prostate cancer, often characterized by an increased invasiveness. We have found that the 5alpha-reduced testosterone derivative, dihydrotestosterone (the most potent natural androgen) inhibits cell migration with an androgen receptor-independent mechanism. We have shown that the dihydrotestosterone metabolite 5alpha-androstane-3beta,17beta-diol (3beta-Adiol), a steroid which does not bind androgen receptors, but efficiently binds the estrogen receptor beta (ERbeta), exerts a potent inhibition of prostate cancer cell migration through the activation of the ERbeta signaling. Very surprisingly, estradiol is not active, suggesting the existence of different pathways for ERbeta activation in prostate cancer cells. Moreover, 3beta-Adiol, through ERbeta, induces the expression of E-cadherin, a protein known to be capable of blocking metastasis formation in breast and prostate cancer cells. The inhibitory effects of 3beta-Adiol on prostate cancer cell migration is counteracted by short interfering RNA against E-cadherin. Altogether, the data showed that (a) circulating testosterone may act with estrogenic effects downstream in the catabolic process present in the prostate, and (b) that the estrogenic effect of testosterone derivatives (ERbeta-dependent) results in the inhibition of cell migration, although it is apparently different from that linked to estradiol on the same receptor and may be protective against prostate cancer invasion and metastasis. These results also shed some light on clinical observations suggesting that alterations in genes coding for 3beta-hydroxysteroid dehydrogenases (the enzymes responsible for 3beta-Adiol formation) are strongly correlated with hereditary prostate cancer.

  20. Molecular biology of beta-estradiol-estrogen receptor complex binding to estrogen response element and the effect on cell proliferation.

    PubMed

    Heger, Zbynek; Zitka, Ondrej; Krizkova, Sona; Beklova, Miroslava; Kizek, Rene; Adam, Vojtech

    2013-01-01

    Group of estrogen pollutants, where the highest estrogen activity is reported at estradiol, is characterized by the fact that even at very low concentrations have potential to cause xenoestrogenic effects. During exposure of excessive amounts of estradiols may be produced undesirable effects resulting in the feminization of males of water organisms. The presence of estradiols in drinking water implies also a risk for the human population in the form of cancers of endocrine systems, abnormalities in reproduction or dysfunctions of neuronal and immune system. Currently, the research is focused mainly to uncover the relationship between the estrogen receptors binding affinity with an estrogen response element and estradiol. In this review we summarized facts about molecular biological principles of β estradiol-estrogen receptor complex binding with estrogen response element and its successive effect on cancer genes expression.

  1. Generation of an estrogen receptor beta-iCre knock-in mouse

    PubMed Central

    Cacioppo, Joseph A; Koo, Yongbum; Patrick Lin, Po-Ching; Osmulski, Sarah A; Ko, Chunjoo D; Ko, CheMyong

    2015-01-01

    A novel knock-in mouse that expresses codon-improved Cre recombinase (iCre) under regulation of the estrogen receptor beta (Esr2) promoter was developed for conditional deletion of genes and for the spatial and/or temporal localization of Esr2 expression. ESR2 is one of two classical nuclear estrogen receptors and displays a spatio-temporal expression pattern and functions that are different from the other estrogen receptor, ESR1. A cassette was constructed that contained iCre, a polyadenylation sequence, and a neomycin selection marker. This construct was used to insert iCre in front of the endogenous start codon of the Esr2 gene of a C57BL/6J embryonic stem cell line via homologous recombination. Resulting Esr2-iCre mice were bred with ROSA26-lacZ and Ai9-RFP reporter mice to visualize cells of functional iCre expression. Strong expression was observed in the ovary, the pituitary, the interstitium of the testes, the head and tail but not body of the epididymis, skeletal muscle, the coagulation gland (anterior prostate), the lung, and the preputial gland. Additional diffuse or patchy expression was observed in the cerebrum, the hypothalamus, the heart, the adrenal gland, the colon, the bladder, and the pads of the paws. Overall, Esr2-iCre mice will serve as a novel line for conditionally ablating genes in Esr2-expressing tissues, identifying novel Esr2-expressing cells, and differentiating the functions of ESR2 and ESR1. PMID:26663382

  2. Activation of transgenic estrogen receptor-beta by selected phytoestrogens in a stably transduced rat serotonergic cell line.

    PubMed

    Amer, Dena A M; Kretzschmar, Georg; Müller, Nicole; Stanke, Nicole; Lindemann, Dirk; Vollmer, Günter

    2010-06-01

    Many flavonoids, a major group of phenolic plant-derived secondary metabolites, are known to possess estrogen-like bioactivities. However, little is known about their estrogenic properties in the central nervous system due to the lack of suitable cellular models expressing sufficient amounts of functional estrogen receptor beta (ERbeta). To overcome this deficit, we have created a cellular model, which is serotonergic in origin, to study properties of estrogenic substances by stably transducing RN46A-B14 cells derived from raphe nuclei region of the rat brain with a lentiviral vector encoding a human ERbeta. We clearly showed that the transgenic human ERbeta is a spontaneously expressed and a functional receptor. We have further assessed the estrogenicity of three different isoflavones and four different naringenin-type flavanones in this cell line utilizing a luciferase reporter gene assay. Genistein (GEN), Daidzein (DAI), Equol (EQ), Naringenin (NAR) and 8-prenylnaringenin (8-PN) showed strong estrogenic activity in a concentration-dependent manner as compared to 7-(O-prenyl)naringenin-4'-acetate (7-O-PN) which was only slightly estrogenic and 6-(1,1-dimethylallyl)naringenin (6-DMAN) that neither showed estrogenic nor anti-estrogenic activity in our model. All observed effects could be antagonized by the anti-estrogen fulvestrant. Moreover, co-treatment of cells with 17beta-estradiol (E2) and either GEN or DAI showed a slight additive effect as compared to EQ. On the other hand, 8-PN in addition to 7-O-PN, but not NAR and 6-DMAN, were able to slightly antagonize the responses triggered by E2. Our newly established cellular model may prove to be a useful tool in explicating basic physiological properties of ERbeta in the brain and may help unravel molecular and cellular mechanisms involved in serotonergic mood regulation by estrogen or potential plant-derived secondary metabolites.

  3. Periodic Estrogen Receptor-Beta Activation: A Novel Approach to Prevent Ischemic Brain Damage.

    PubMed

    Cue, Lauren; Diaz, Francisca; Briegel, Karoline J; Patel, Hersila H; Raval, Ami P

    2015-10-01

    In women, the risk for cerebral ischemia climbs rapidly after menopause. At menopause, production of ovarian hormones; i.e., progesterone and estrogen, slowly diminishes. Estrogen has been suggested to confer natural protection to premenopausal women from ischemic stroke and some of its debilitating consequences. This notion is also strongly supported by laboratory studies showing that a continuous chronic 17β-estradiol (E2; a potent estrogen) regimen protects brain from ischemic injury. However, concerns regarding the safety of the continuous intake of E2 were raised by the failed translation to the clinic. Recent studies demonstrated that repetitive periodic E2 pretreatments, in contrast to continuous E2 treatment, provided neuroprotection against cerebral ischemia in ovariectomized rats. Periodic E2 pretreatment protects hippocampal neurons through activation of estrogen receptor subtype beta (ER-β). Apart from neuroprotection, periodic activation of ER-β in ovariectomized rats significantly improves hippocampus-dependent learning and memory. Difficulties in learning and memory loss are the major consequence of ischemic brain damage. Periodic ER-β agonist pretreatment may provide pharmacological access to a protective state against ischemic stroke and its debilitating consequences. The use of ER-β-selective agonists constitutes a safer target for future research than ER-α agonist or E2, inasmuch as it lacks the ability to stimulate the proliferation of breast or endometrial tissue. In this review, we highlight ER-β signaling as a guide for future translational research to reduce cognitive decline and cerebral ischemia incidents/impact in post-menopausal women, while avoiding the side effects produced by chronic E2 treatment.

  4. INTERACTION OF PAH-RELATED COMPOUNDS WITH THE ALPHA AND BETA ISOFORMS OF ESTROGEN RECEPTOR. (R826192)

    EPA Science Inventory

    The ability of several 4- and 5-ring polycyclic aromatic hydrocarbons (PAHs), heterocyclic PAHs, and their monohydroxy derivatives to interact with the estrogen receptor (ER) alpha and beta isoforms was examined. Only compounds possessing a hydroxyl group were able to compete wit...

  5. Genes, Gender, Environment, and Novel Functions of Estrogen Receptor Beta in the Susceptibility to Neurodevelopmental Disorders

    PubMed Central

    Varshney, Mukesh; Nalvarte, Ivan

    2017-01-01

    Many neurological disorders affect men and women differently regarding prevalence, progression, and severity. It is clear that many of these disorders may originate from defective signaling during fetal or perinatal brain development, which may affect males and females differently. Such sex-specific differences may originate from chromosomal or sex-hormone specific effects. This short review will focus on the estrogen receptor beta (ERβ) signaling during perinatal brain development and put it in the context of sex-specific differences in neurodevelopmental disorders. We will discuss ERβ’s recent discovery in directing DNA de-methylation to specific sites, of which one such site may bear consequences for the susceptibility to the neurological reading disorder dyslexia. We will also discuss how dysregulations in sex-hormone signaling, like those evoked by endocrine disruptive chemicals, may affect this and other neurodevelopmental disorders in a sex-specific manner through ERβ. PMID:28241485

  6. Genes, Gender, Environment, and Novel Functions of Estrogen Receptor Beta in the Susceptibility to Neurodevelopmental Disorders.

    PubMed

    Varshney, Mukesh; Nalvarte, Ivan

    2017-02-23

    Many neurological disorders affect men and women differently regarding prevalence, progression, and severity. It is clear that many of these disorders may originate from defective signaling during fetal or perinatal brain development, which may affect males and females differently. Such sex-specific differences may originate from chromosomal or sex-hormone specific effects. This short review will focus on the estrogen receptor beta (ERβ) signaling during perinatal brain development and put it in the context of sex-specific differences in neurodevelopmental disorders. We will discuss ERβ's recent discovery in directing DNA de-methylation to specific sites, of which one such site may bear consequences for the susceptibility to the neurological reading disorder dyslexia. We will also discuss how dysregulations in sex-hormone signaling, like those evoked by endocrine disruptive chemicals, may affect this and other neurodevelopmental disorders in a sex-specific manner through ERβ.

  7. The role of estrogen receptor {beta} (ER{beta}) in malignant diseases-A new potential target for antiproliferative drugs in prevention and treatment of cancer

    SciTech Connect

    Warner, Margaret; Gustafsson, Jan-Ake

    2010-05-21

    The discovery of ER{beta} in the middle of the 1990s represents a paradigm shift in our understanding of estrogen signaling. It has turned out that estrogen action is not mediated by one receptor, ER{alpha}, but by two balancing factors, ER{alpha} and ER{beta}, which are often antagonistic to one another. Excitingly, ER{beta} has been shown to be widespread in the body and to be involved in a multitude of physiological and pathophysiological events. This has led to a strong interest of the pharmaceutical industry to target ER{beta} by drugs against various diseases. In this review, focus is on the role of ER{beta} in malignant diseases where the anti proliferative activity of ER{beta} gives hope of new therapeutic approaches.

  8. Increased mandibular condylar growth in mice with estrogen receptor beta deficiency.

    PubMed

    Kamiya, Yosuke; Chen, Jing; Xu, Manshan; Utreja, Achint; Choi, Thomas; Drissi, Hicham; Wadhwa, Sunil

    2013-05-01

    Temporomandibular joint (TMJ) disorders predominantly afflict women of childbearing age, suggesting a role for female hormones in the disease process. In long bones, estrogen acting via estrogen receptor beta (ERβ) inhibits axial skeletal growth in female mice. However, the role of ERβ in the mandibular condyle is largely unknown. We hypothesize that female ERβ-deficient mice will have increased mandibular condylar growth compared to wild-type (WT) female mice. This study examined female 7-day-old, 49-day-old, and 120-day-old WT and ERβ knockout (KO) mice. There was a significant increase in mandibular condylar cartilage thickness as a result of an increased number of cells, in the 49-day-old and 120-day-old female ERβ KO compared with WT controls. Analysis in 49-day-old female ERβ KO mice revealed a significant increase in collagen type X, parathyroid hormone-related protein (Pthrp), and osteoprotegerin gene expression and a significant decrease in receptor activator for nuclear factor κ B ligand (Rankl) and Indian hedgehog (Ihh) gene expression, compared with WT controls. Subchondral bone analysis revealed a significant increase in total condylar volume and a decrease in the number of osteoclasts in the 49-day-old ERβ KO compared with WT female mice. There was no difference in cell proliferation in condylar cartilage between the genotypes. However, there were differences in the expression of proteins that regulate the cell cycle; we found a decrease in the expression of Tieg1 and p57 in the mandibular condylar cartilage from ERβ KO mice compared with WT mice. Taken together, our results suggest that ERβ deficiency increases condylar growth in female mice by inhibiting the turnover of fibrocartilage.

  9. Resveratrol and estradiol rapidly activate MAPK signaling through estrogen receptors alpha and beta in endothelial cells.

    PubMed

    Klinge, Carolyn M; Blankenship, Kristy A; Risinger, Kelly E; Bhatnagar, Shephali; Noisin, Edouard L; Sumanasekera, Wasana K; Zhao, Lei; Brey, Darren M; Keynton, Robert S

    2005-03-04

    Vascular endothelial cells (EC) are an important target of estrogen action through both the classical genomic (i.e. nuclear-initiated) activities of estrogen receptors alpha and beta (ERalpha and ERbeta) and the rapid "non-genomic" (i.e. membrane-initiated) activation of ER that stimulates intracellular phosphorylation pathways. We tested the hypothesis that the red wine polyphenol trans-resveratrol activates MAPK signaling via rapid ER activation in bovine aortic EC, human umbilical vein EC, and human microvascular EC. We report that bovine aortic EC, human umbilical vein EC, and human microvascular EC express ERalpha and ERbeta. We demonstrate that resveratrol and estradiol (E(2)) rapidly activated MAPK in a MEK-1, Src, matrix metalloproteinase, and epidermal growth factor receptor-dependent manner. Importantly, resveratrol activated MAPK and endothelial nitric-oxide synthase (eNOS) at nm concentrations (i.e. an order of magnitude less than that required for ER genomic activity) and concentrations possibly achieved transiently in serum following oral red wine consumption. Co-treatment with ER antagonists ICI 182,780 or 4-hydroxytamoxifen blocked resveratrol- or E(2)-induced MAPK and eNOS activation, indicating ER dependence. We demonstrate for the first time that ERalpha-and ERbeta-selective agonists propylpyrazole triol and diarylpropionitrile, respectively, stimulate MAPK and eNOS activity. A red but not a white wine extract also activated MAPK, and activity was directly correlated with the resveratrol concentration. These data suggest that ER may play a role in the rapid effects of resveratrol in EC and that some of the atheroprotective effects of resveratrol may be mediated through rapid activation of ER signaling in EC.

  10. Phosphorylation of estrogen receptor beta at serine 105 is associated with good prognosis in breast cancer.

    PubMed

    Hamilton-Burke, Werbena; Coleman, Louise; Cummings, Michele; Green, Caroline A; Holliday, Deborah L; Horgan, Kieran; Maraqa, Loaie; Peter, Mark B; Pollock, Steven; Shaaban, Abeer M; Smith, Laura; Speirs, Valerie

    2010-09-01

    Estrogen receptor (ER) action is modulated by posttranslational modifications. Although ERalpha phosphorylation correlates with patient outcome, ERbeta is similarly phosphorylated but its significance in breast cancer has not been addressed. We investigated whether ERbeta that is phosphorylated at serine 105 (S105-ERbeta) is expressed in breast cancer and assessed potential clinical implications of this phosphorylation. Following antibody validation, S105-ERbeta expression was studied in tissue microarrays comprising 108 tamoxifen-resistant and 351 tamoxifen-sensitive cases and analyzed against clinical data. S105-ERbeta regulation in vitro was assessed by Western blot, flow cytometry, and immunofluorescence. Nuclear S105-ERbeta was observed in breast carcinoma and was associated with better survival (Allred score > or =3), even in tamoxifen-resistant cases, and additionally correlated with ERbeta1 and ERbeta2 expression. Distinct S105-ERbeta nuclear speckles were seen in some higher grade tumors. S105-ERbeta levels increased in MCF-7 cells in response to 17beta-estradiol, the ERbeta-specific agonist diarylpropionitrile, and the partial ERbeta-agonist genistein. S105-ERbeta nuclear speckles were also seen in MCF-7 cells and markedly increased in size and number at 24 hours following 17beta-estradiol and, in particular diarylpropionitrile, treatment. These speckles were coexpressed with ERbeta1 and ERbeta2. Presence of S105-ERbeta in breast cancer and association with improved survival, even in endocrine resistant breast tumors suggest S105-ERbeta might be a useful additional prognostic marker in this disease.

  11. Rapid and estrogen receptor beta mediated actions in the hippocampus mediate some functional effects of estrogen

    PubMed Central

    Walf, Alicia A.; Frye, Cheryl A.

    2008-01-01

    The steroid hormone, estradiol (E2), has numerous targets in the central nervous system, including the hippocampus, which plays a key role in cognition and affective behavior. This review focuses on our evidence from studies in rodents that E2 has diverse mechanisms in the hippocampus for its functional effects E2 has rapid, membrane-mediated effects in the hippocampus to enhance cognitive performance. Administration of E2 to the hippocampus of rats for 10 minutes following training enhances performance in a hippocampus-mediated task. Increased cell firing in the hippocampus occurs within this short time frame. Furthermore, administration of free E2 or an E2 conjugate, E2:bovine serum albumin (BSA), to the hippocampus produces similar performance-enhancing effects in this task, suggesting that E2 has membrane actions in the hippocampus for these effects. Further evidence that E2 has rapid, membrane-mediated effects is that co-administration of E2 and inhibitors of mitogen activated protein kinase (MAPK), rather than intracellular E2 receptors (ERs) or protein synthesis, attenuate the enhancing effects of E2 in this task. Despite these data that demonstrate E2 can have rapid and/or membrane-mediated effects in the hippocampus, there is clear evidence to suggest that intracellular ERs, particularly the β (rather than α) isoform of ERs, may be important targets for E2’s functional effects for hippocampal processes. Administration of ligands that are specific for ERβ, but not ERα, have enhancing effects on hippocampal processes similar to that of E2 (which has similar affinity for ERα and ERβ). These effects are attenuated when ERβ expression is knocked down in transgenic models or with central administration of antisense oligonucleotides. Thus, there may be a convergence of E2’s actions through rapid, membrane-mediated effects and intracellular ERs and in the hippocampus for these functional effects. PMID:18342348

  12. PGC-1{beta} regulates mouse carnitine-acylcarnitine translocase through estrogen-related receptor {alpha}

    SciTech Connect

    Gacias, Mar; Perez-Marti, Albert; Pujol-Vidal, Magdalena; Marrero, Pedro F.; Haro, Diego; Relat, Joana

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer The Cact gene is induced in mouse skeletal muscle after 24 h of fasting. Black-Right-Pointing-Pointer The Cact gene contains a functional consensus sequence for ERR. Black-Right-Pointing-Pointer This sequence binds ERR{alpha} both in vivo and in vitro. Black-Right-Pointing-Pointer This ERRE is required for the activation of Cact expression by the PGC-1/ERR axis. Black-Right-Pointing-Pointer Our results add Cact as a genuine gene target of these transcriptional regulators. -- Abstract: Carnitine/acylcarnitine translocase (CACT) is a mitochondrial-membrane carrier proteins that mediates the transport of acylcarnitines into the mitochondrial matrix for their oxidation by the mitochondrial fatty acid-oxidation pathway. CACT deficiency causes a variety of pathological conditions, such as hypoketotic hypoglycemia, cardiac arrest, hepatomegaly, hepatic dysfunction and muscle weakness, and it can be fatal in newborns and infants. Here we report that expression of the Cact gene is induced in mouse skeletal muscle after 24 h of fasting. To gain insight into the control of Cact gene expression, we examine the transcriptional regulation of the mouse Cact gene. We show that the 5 Prime -flanking region of this gene is transcriptionally active and contains a consensus sequence for the estrogen-related receptor (ERR), a member of the nuclear receptor family of transcription factors. This sequence binds ERR{alpha}in vivo and in vitro and is required for the activation of Cact expression by the peroxisome proliferator-activated receptor gamma coactivator (PGC)-1/ERR axis. We also demonstrate that XTC790, the inverse agonist of ERR{alpha}, specifically blocks Cact activation by PGC-1{beta} in C2C12 cells.

  13. Developmental expression of estrogen receptor beta in the brain of prairie voles (Microtus ochrogaster).

    PubMed

    Ploskonka, Stephanie D; Eaton, Jennifer L; Carr, Michael S; Schmidt, Jennifer V; Cushing, Bruce S

    2016-03-01

    Here, for the first time, the expression of estrogen receptor beta (ERβ) is characterized in the brains of the highly prosocial prairie vole (Microtus ochrogaster). ERβ immunoreactivity was compared in weanlings (postnatal Day 21) and adult males and females. The results indicate several major findings. First, unlike ERα, ERβ expression is not sexually dimorphic. Second, the adult pattern of ERβ-IR is established at the time of weaning, as there were no age-dependent effects on distribution. Finally, ERβ does not appear to be as widely distributed in voles compared with rats and mice. High levels of ERβ-IR were observed in several regions/nuclei within the medial pre-optic area, ventrolateral pre-optic nuclei, and in the hypothalamus, especially in the paraventricular and supraoptic nuclei. The visualization of ERβ in prairie voles is important as the socially monogamous prairie vole functions as a human relevant model system for studying the expression of social behavior and social deficit disorders. Future studies will now be able to determine the effect of treatments on the expression and/or development of ERβ in this highly social species.

  14. Tamoxifen regulates cell fate through mitochondrial estrogen receptor beta in breast cancer.

    PubMed

    Razandi, M; Pedram, A; Jordan, V C; Fuqua, S; Levin, E R

    2013-07-04

    Tamoxifen (TAM) has both cytostatic and cytotoxic properties for breast cancer. TAM engaged mitochondrial estrogen receptor beta (ERβ) as an antagonist in MCF7-BK cells, increasing reactive oxygen species (ROS) concentrations from the mitochondria that were required for cytotoxicity. In part, this derived from TAM downregulating manganese superoxide dismutase (MnSOD) activity by causing the nitrosylation of tyrosine 34, thereby increasing ROS. ROS-activated protein kinase C delta and c-jun N-terminal kinases, resulting in the mitochondrial translocation of Bax and cytochrome C release. Interestingly, TAM failed to cause high ROS levels or induce cell death in MCF7-BK-TR cells due to stimulation of MnSOD activity through agonistic effects at mitochondrial ERβ. In several mouse xenograft models, lentiviral shRNA-induced knockdown of MnSOD caused tumors that grew in the presence of TAM to undergo substantial apoptosis. Tumor MnSOD and mitochondrial ERβ are therefore targets for therapeutic intervention to reverse TAM resistance and enhance a cell death response.

  15. The role of estrogen receptor beta in transplacental cancer prevention by indole-3-carbinol

    PubMed Central

    Benninghoff, Abby D.; Williams, David E.

    2013-01-01

    In the present study, the efficacy of indole-3-carbinol (I3C), a key bioactive component of cruciferous vegetables, for prevention of cancer in offspring exposed in utero to the environmental carcinogen dibenzo[def,p]chrysene (DBC) was evaluated using an estrogen receptor beta (ERβ) knockout mouse model. I3C was provided either through the maternal diet coincident with carcinogen exposure during pregnancy or directly to offspring post initiation with DBC. I3C was effective at reducing T-cell acute lymphoblastic lymphoma/leukemia (T-ALL)-related mortality in offspring only if provided via the maternal diet, although a gender difference in the role of ERβ in mediating this response was evident. In female offspring, chemoprevention of T-ALL by maternal dietary I3C required expression of ERβ; survival in Esr2 wild-type and heterozygous female offspring was >90% compared to 66% in Esr2 null females. Alternatively, ERβ status did not significantly impact the transplacental chemoprevention by I3C in males. The possible role of ERβ in mediating lung carcinogenesis or chemoprevention by I3C was similarly complicated. Lung tumor incidence was unaltered by either dietary intervention, whereas lung tumor multiplicity was substantially reduced in Esr2 null females on the control diet and marginally lower in Esr2 null males exposed to I3C via the maternal diet compared to their wild-type and heterozygous counterparts. These findings suggest that I3C may act via ERβ to prevent or suppress DBC-initiated transplacental carcinogenesis, but that the involvement of this receptor appears to differ depending on the cancer type and gender of the offspring. PMID:23447562

  16. Period 1 and estrogen receptor-beta are downregulated in Chinese colon cancers.

    PubMed

    Wang, Yupeng; Xing, Tonghai; Huang, Li; Song, Guohe; Sun, Xing; Zhong, Lin; Fan, Junwei; Yan, Dongwang; Zhou, Chongzhi; Cui, Feifei; Yu, Fudong; Chen, Jian; Yu, Yang; Li, Chao; Tang, Huamei; Peng, Zhihai; Wang, Xiaoliang

    2015-01-01

    To investigate whether Period 1 (PER1) and Estrogen receptor-beta (ER2) are associated with occurrence and development of Chinese colorectal cancers. By using RT-quantitative PCR, tissue microarray (TMA) and immunohistochemistry, we detected mRNA levels and protein levels of PER1 and ER2 in the cancerous tissues and paired normal adjacent tissues in patients with colorectal cancer. Survival analyses were performed by the Kaplan-Meier method utilizing log-rank test and univariate and multivariate Cox proportional modeling to measure 5-year disease-free survival (DFS) and overall survival (OS). Real-time PCR showed that, the delta Ct value (tumor tissue vs. normal mucosa) of PER1 or ER2 is 8.51 ± 2.81 vs. 7.34 ± 2.08 or 12.39 ± 2.43 vs. 9.76 ± 1.75, expression of PER1 and ER2 decreased significantly in tumor tissues compared with noncancerous mucosas of patients with or without metastasis (both of P values <0.001). Spearman test revealed that PER1 and ER2 were significantly down-regulated in cancerous tissues (r=0.283; P<0.001) which was also confirmed by immunohistochemistry of specimens from 203 colon cancer patients in a TMA format. The reduction of PER1 was associated with gender and distant metastasis (P=0.037 and P<0.001, respectively) whereas the decline of ER2 was associated with age (P=0.043) by analyzing the clinical data. However, we were not capable of detecting any association between PER1 level or ER2 level and overall survival (OS) or disease free survival (DFS). It is the first observation of correlated reduction of PER1 and ER2 in Chinese colon cancers, and they do play a certain role in colorectal cancer.

  17. Period 1 and estrogen receptor-beta are downregulated in Chinese colon cancers

    PubMed Central

    Wang, Yupeng; Xing, Tonghai; Huang, Li; Song, Guohe; Sun, Xing; Zhong, Lin; Fan, Junwei; Yan, Dongwang; Zhou, Chongzhi; Cui, Feifei; Yu, Fudong; Chen, Jian; Yu, Yang; Li, Chao; Tang, Huamei; Peng, Zhihai; Wang, Xiaoliang

    2015-01-01

    To investigate whether Period 1 (PER1) and Estrogen receptor-beta (ER2) are associated with occurrence and development of Chinese colorectal cancers. By using RT-quantitative PCR, tissue microarray (TMA) and immunohistochemistry, we detected mRNA levels and protein levels of PER1 and ER2 in the cancerous tissues and paired normal adjacent tissues in patients with colorectal cancer. Survival analyses were performed by the Kaplan-Meier method utilizing log-rank test and univariate and multivariate Cox proportional modeling to measure 5-year disease-free survival (DFS) and overall survival (OS). Real-time PCR showed that, the delta Ct value (tumor tissue vs. normal mucosa) of PER1 or ER2 is 8.51±2.81 vs. 7.34±2.08 or 12.39±2.43 vs. 9.76±1.75, expression of PER1 and ER2 decreased significantly in tumor tissues compared with noncancerous mucosas of patients with or without metastasis (both of P values <0.001). Spearman test revealed that PER1 and ER2 were significantly down-regulated in cancerous tissues (r=0.283; P<0.001) which was also confirmed by immunohistochemistry of specimens from 203 colon cancer patients in a TMA format. The reduction of PER1 was associated with gender and distant metastasis (P=0.037 and P<0.001, respectively) whereas the decline of ER2 was associated with age (P=0.043) by analyzing the clinical data. However, we were not capable of detecting any association between PER1 level or ER2 level and overall survival (OS) or disease free survival (DFS). It is the first observation of correlated reduction of PER1 and ER2 in Chinese colon cancers, and they do play a certain role in colorectal cancer. PMID:26339386

  18. Estrogen receptor-beta expression in invasive breast cancer in relation to molecular phenotype: results from the Nurses' Health Study.

    PubMed

    Marotti, Jonathan D; Collins, Laura C; Hu, Rong; Tamimi, Rulla M

    2010-02-01

    The expression of estrogen receptor-alpha (ER-alpha) and related genes has emerged as one of the major determinants of molecular classification of invasive breast cancers. Expression of a second ER, estrogen receptor-beta (ER-beta), has not been previously evaluated in a large population-based study. Therefore, we examined ER-beta expression in a large population of women with breast cancer to assess its relationship to molecular categories of invasive breast cancer. We constructed tissue microarrays from paraffin blocks of 3093 breast cancers that developed in women enrolled in the Nurses' Health Study. Tissue microarray sections were immunostained for ER-alpha, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), cytokeratin 5/6, epidermal growth factor receptor (EGFR) and with a monoclonal antibody to ER-beta. Cancers were categorized as luminal A (ER-alpha+ and/or PR+ and HER2-); luminal B (ER-alpha+ and/or PR+ and HER2+); HER2 (ER-alpha- and PR- and HER2+); and basal-like (ER-alpha-, PR-, HER2- and EGFR or cytokeratin 5/6+). The relationship between expression of ER-beta and molecular class of invasive breast cancer was analyzed. Overall, 68% of breast carcinomas were ER-beta+. Expression of ER-beta was significantly associated with expression of ER-alpha (P<0.0001) and PR (P<0.0001), and was inversely related to expression of HER2 (P=0.004), CK5/6 (P=0.02) and EGFR (P=0.006). Among 2170 invasive cancers with complete immunophenotypic data, 73% were luminal A, 5% luminal B, 6 % HER2 and 11% basal-like. ER-beta expression was significantly related to molecular category (P<0.0001) and was more common in luminal A (72% of cases) and B (68% of cases) than in HER2 or basal-like types. However, despite their being defined by the absence of ER-alpha expression, 55% of HER2-type and 60% of basal-like cancers showed expression of ER-beta. The role of ER-beta in the development and progression of breast cancers defined by lack of expression of ER

  19. Involvement of estrogen receptor alpha, beta and oxytocin in social discrimination: A detailed behavioral analysis with knockout female mice.

    PubMed

    Choleris, E; Ogawa, S; Kavaliers, M; Gustafsson, J-A; Korach, K S; Muglia, L J; Pfaff, D W

    2006-10-01

    Social recognition, processing, and retaining information about conspecific individuals is crucial for the development of normal social relationships. The neuropeptide oxytocin (OT) is necessary for social recognition in male and female mice, with its effects being modulated by estrogens in females. In previous studies, mice whose genes for the estrogen receptor-alpha (alpha-ERKO) and estrogen receptor-beta (beta-ERKO) as well as OTKO were knocked out failed to habituate to a repeatedly presented conspecific and to dishabituate when the familiar mouse is replaced by a novel animal (Choleris et al. 2003, Proc Natl Acad Sci USA 100, 6192-6197). However, a binary social discrimination assay, where animals are given a simultaneous choice between a familiar and a previously unknown individual, offers a more direct test of social recognition. Here, we used alpha-ERKO, beta-ERKO, and OTKO female mice in the binary social discrimination paradigm. Differently from their wild-type controls, when given a choice, the KO mice showed either reduced (beta-ERKO) or completely impaired (OTKO and alpha-ERKO) social discrimination. Detailed behavioral analyses indicate that all of the KO mice have reduced anxiety-related stretched approaches to the social stimulus with no overall impairment in horizontal and vertical activity, non-social investigation, and various other behaviors such as, self-grooming, digging, and inactivity. Therefore, the OT, ER-alpha, and ER-beta genes are necessary, to different degrees, for social discrimination and, thus, for the modulation of social behavior (e.g. aggression, affiliation).

  20. Steroidal affinity labels of the estrogen receptor. 3. Estradiol 11 beta-n-alkyl derivatives bearing a terminal electrophilic group: antiestrogenic and cytotoxic properties.

    PubMed

    Lobaccaro, C; Pons, J F; Duchesne, M J; Auzou, G; Pons, M; Nique, F; Teutsch, G; Borgna, J L

    1997-07-04

    With the aim of developing a new series of steroidal affinity labels of the estrogen receptor, six electrophilic 11 beta-ethyl (C2), 11 beta-butyl (C4), or 11 beta-decyl (C10) derivatives of estradiol bearing an 11 beta-terminal electrophilic functionality, i.e. bromine (C4), (methylsulfonyl)oxy (C2 and C4), bromoacetamido (C2 and C4), and (p-tolylsulfonyl)oxy (C10), were synthesized. The range of their affinity constants for binding the estrogen receptor was 0.4-37% that of estradiol; the order of increasing affinity (i) relative to the 11 beta-alkyl arm was ethyl < butyl and (ii) relative to the electrophilic functionality was bromoacetamido < bromine < (methylsulfonyl)oxy. Regardless of the conditions used, including prolonged exposure of the receptor to various pH levels (7-9) and temperatures (0-25 degrees C), the extent of receptor affinity labeling by the 11 beta-ethyl and 11 beta-butyl compounds, if any, was under 10%. This was in sharp contrast to results obtained using 11 beta-((tosyloxy)decyl)estradiol which labeled from 60% to 90% of the receptor hormone-binding sites with an EC50 of approximately 10 nM. Estrogenic and antiestrogenic activities of the compounds were determined using the MVLN cell line, which was established from the estrogen-responsive mammary tumor MCF-7 cells by stable transfection of a recombinant estrogen-responsive luciferase gene. The two 11 beta-ethyl compounds were mainly estrogenic, whereas the three 11 beta-butyl and the 11 beta-decyl compounds essentially showed antiestrogenic activity. The fact that the chemical reactivities of 11 beta-ethyl and 11 beta-butyl compounds were not compromised by interaction with the estrogen receptor made the synthesized high-affinity compounds potential cytotoxic agents which might be able to exert either (i) a specific action on estrogen-regulated genes or (ii) a more general action in estrogen-target cells. Therefore the ability of the compounds (1) to irreversibly abolish estrogen

  1. Association of estrogen receptor beta variants and serum levels of estradiol with risk of colorectal cancer: a case control study

    PubMed Central

    2012-01-01

    Background Endogenous estrogens may play a vital role in colorectal tumorigenesis. Estrogen receptor beta is the predominant subtype which mediates the biological effect of estrogens, while loss of expression of estrogen receptor beta has been indicated as a common step in the development of colorectal cancer (CRC). Epidemiological studies have revealed several functional polymorphisms of estrogen receptor beta (ESR2) for cancer risk, but relevant study in CRC is limited, particularly in men. This study aimed to investigate the association of circulating estradiol and variations of ESR2 with CRC risk in men. Methods We initiated a case–control study consisting of 390 patients with CRC and 445 healthy controls in men only. We genotyped ESR2 single nucleotide polymorphisms (SNPs) rs1256049 and rs4986938 and measured serum estradiol concentration using chemilluminescence immunoassay. Multivariable logistic regression model was performed to evaluate the associations between these variables and CRC risk. Results ESR2 rs1256049 CT/TT genotypes were associated with reduced risk of CRC (odds ratio [OR], 0.7, 95% confidence interval [CI], 0.5–1.0), while rs4986938 CT/TT genotypes were associated with increased risk of CRC (OR, 1.5, 95% CI, 1.0–2.1). In addition, the CRC risk increased with the number of risk genotypes of these two SNPs in a dose–response manner (Ptrend, 0.003). Specifically, subjects carrying risk genotypes of both SNPs had the highest risk of CRC (OR, 2.0, 95% CI, 1.3–3.3.). Moreover, serum estradiol concentration alone was associated with risk of CRC in men (OR, 1.2, 95% CI, 1.0–1.3). However, individuals presenting both rs4986938 CT/TT genotypes and high level of serum estradiol had a high risk of CRC (OR, 2.3, 95% CI, 1.4–3.9), compared with those presenting CC genotype and low level of serum estradiol. The similar joint results were not observed for SNP rs1256049. Conclusions These results suggest that endogenous estrogen and genetic

  2. Human estrogen receptor beta-specific monoclonal antibodies: characterization and use in studies of estrogen receptor beta protein expression in reproductive tissues.

    PubMed

    Choi, I; Ko, C; Park-Sarge, O K; Nie, R; Hess, R A; Graves, C; Katzenellenbogen, B S

    2001-07-05

    Investigation of the role of the second, more recently described estrogen receptor, denoted ERbeta, will be critical in understanding the molecular mechanisms underlying tissue-specific gene regulation by estrogens. Expression of ERbeta in a variety of tissues has been examined predominantly at the mRNA level, and there is little information regarding the cellular localization and size of the endogenous ERbeta protein, due, in part, to the limited availability of human ERbeta-specific antibodies. Thus, our aim was to generate specific antibodies to human ERbeta and use them to determine the tissue-specific distribution and size(s) of the ERbeta protein. To this end, we have cloned three different hybridoma cell lines that produce monoclonal antibodies specific for the hormone-binding domain of human ERbeta. The antibodies, made in mice against human ERbeta amino acids 256-505 (hormone binding domain lacking the F domain), are designated CFK-E12 (E12), CMK-A9 (A9) and CWK-F12 (F12) and were determined to be the IgG gamma1 isotype for E12, and IgG gamma2b for A9 and F12. All three monoclonal antibodies could be used to detect in vitro translated, baculovirus expressed, and cell transfected and expressed ERbeta protein by Western blot analyses, and all failed to detect ERalpha. A9 and F12 were able to immunoprecipitate efficiently the native form of ERbeta protein in the presence and absence of estradiol. Epitope mapping studies indicate that the E12 and F12 antibodies recognize overlapping peptide sequences in the N-terminal region of the hormone-binding domain, a region that is highly conserved among species. Immunocytochemical studies with these antibodies reveal nuclear-specific localization of the ERbeta protein in granulosa cells of the rat ovary. Nuclear ERbeta is also specifically localized in epithelial and some stromal cells of mouse and rat epididymis. Western blot analysis with protein extracts from ovarian granulosa cells of human, rat, mouse, and pig

  3. Distribution patterns of estrogen receptor alpha and beta in the human cortex and hippocampus during development and adulthood.

    PubMed

    González, Miriam; Cabrera-Socorro, Alfredo; Pérez-García, Carlos G; Fraser, James D; López, Francisco J; Alonso, Rafael; Meyer, Gundela

    2007-08-20

    The expression of estrogen receptors (ERs) in the developing and adult human brain has not been clearly established, although estrogens are crucial for neuronal differentiation, synapse formation, and cognitive functions. By using immunohistochemistry, we have studied the distribution of ER alpha and ER beta in human cerebral cortex and hippocampus from early prenatal stages to adult life. ER alpha was detected in the cortex at 9 gestational weeks (GW), with a high expression in proliferating zones and the cortical plate. The staining intensity decreased gradually during prenatal development but increased again from birth to adulthood. In contrast, ER beta was first detected at 15 GW in proliferating zones, and at 16/17 GW, numerous ER beta immunopositive cells were also observed in the cortical plate. ER beta expression persisted in the adult cortex, being widely distributed throughout cortical layers II-VI. In addition, from around 15 GW to adulthood, ER alpha and ER beta were expressed in human hippocampus mainly in pyramidal cells of Ammon's horn and in the dentate gyrus. Western blotting and immunohistochemistry in the adult cerebral cortex and hippocampus revealed lower protein expression of ER alpha compared with ER beta. Double immunostaining showed that during fetal life both ERs are expressed in neurons as well as in radial glia, although only ER alpha is expressed in the Cajal-Retzius neurons of the marginal zone. These observations demonstrate that the expression of ER alpha and ER beta displays different spatial-temporal patterns during human cortical and hippocampal development and suggest that both ERs may play distinct roles in several processes related to prenatal brain development.

  4. Water Sparing in Chronic Ethanol Exposure is Associated With Elevated Renal Estrogen Receptor Beta and Vasopressin V2 Receptor mRNA in the Female Rate

    DTIC Science & Technology

    2007-12-01

    quality as a thesis for the degree of Master of Science in Medical and Molecular Physiology. THESIS COMMITTEE Chairperson ii TABLE OF CONTENTS List of...of biology = Revista brasleira de biologia 62, 609-614 20. Bevan, D. R. (1978) Osmometry. 1. Terminology and principles of measurement. Anaesthesia 33... molecular endocrinology 24, 145-155 32. Suzuki, S., and Handa, R. J. (2004) Regulation of estrogen receptor-beta expression in the female rat

  5. Stimulation of catecholamine synthesis through unique estrogen receptors in the bovine adrenomedullary plasma membrane by 17{beta}-estradiol

    SciTech Connect

    Yanagihara, Nobuyuki . E-mail: yanagin@med.uoeh-u.ac.jp; Liu, Minhui; Toyohira, Yumiko; Tsutsui, Masato; Ueno, Susumu; Shinohara, Yuko; Takahashi, Kojiro; Tanaka, Kazumi

    2006-01-13

    Incubation of cultured bovine adrenal medullary cells with 17{beta}-estradiol (E{sub 2}) (0.3-100 nM) or membrane-impermeable E{sub 2}-bovine serum albumin (100 nM) acutely increased {sup 14}C-catecholamine synthesis from [{sup 14}C]tyrosine. The stimulatory effect of E{sub 2} was not inhibited by ICI182,780, a nuclear estrogen receptor inhibitor. E{sub 2} also increased tyrosine hydroxylase activity and p44/42MAPK phosphorylation, the former of which was attenuated by U0126, an inhibitor of p44/42MAPK kinase. The plasma membrane isolated from the gland showed two classes of specific binding sites of [{sup 3}H]E{sub 2} with apparent K {sub d}s of 3.2 and 106 nM, and B {sub max}s of 0.44 and 8.5 pmol/mg protein, respectively. The high-affinity binding of [{sup 3}H]E{sub 2} was most strongly inhibited by E{sub 2} and phytoestrogens, and to lesser extents by other steroid hormones, while it was enhanced by ICI182,780 and environmental estrogenic pollutants. These findings suggest that E{sub 2} acutely stimulates catecholamine synthesis via activation of p44/42MAPK through unique estrogen receptors in the plasma membrane of bovine adrenal medulla.

  6. Estrogen receptor beta, a possible tumor suppressor involved in ovarian carcinogenesis

    PubMed Central

    Lazennec, Gwendal

    2006-01-01

    Ovarian cancer is one of the leading cause of death from gynecological tumors in women. Several lines of evidence suggest that estrogens may play an important role in ovarian carcinogenesis, through their receptors, ERα and ERβ. Interestingly, malignant ovarian tumors originating from epithelial surface constitute about 90% of ovarian cancers and expressed low levels of ERβ, compared to normal tissues. In addition, restoration of ERβ in ovarian cancer cells, leads to strong inhibition of their proliferation and invasion, while apoptosis is enhanced. In this manuscript, recent data suggesting a possible tumor-suppressor role for ERβ in ovarian carcinogenesis are discussed. PMID:16399219

  7. Estrogen receptor alpha signaling in inflammatory leukocytes is dispensable for 17beta-estradiol-mediated inhibition of experimental autoimmune encephalomyelitis.

    PubMed

    Garidou, Lucile; Laffont, Sophie; Douin-Echinard, Victorine; Coureau, Christiane; Krust, Andrée; Chambon, Pierre; Guéry, Jean-Charles

    2004-08-15

    Estrogen treatment has been shown to exert a protective effect on experimental autoimmune encephalomyelitis (EAE), and is under clinical trial for multiple sclerosis. Although it is commonly assumed that estrogens exert their effect by modulating immune functions, we show in this study that 17beta-estradiol (E2) treatment can inhibit mouse EAE without affecting autoantigen-specific T cell responsiveness and type 1 cytokine production. Using mutant mice in which estrogen receptor alpha (ERalpha) has been unambiguously inactivated, we found that ERalpha was responsible for the E2-mediated inhibition of EAE. We next generated irradiation bone marrow chimeras in which ERalpha expression was selectively impaired in inflammatory T lymphocytes or was limited to the radiosensitive hemopoietic compartment. Our data show that the protective effect of E2 on clinical EAE and CNS inflammation was not dependent on ERalpha signaling in inflammatory T cells. Likewise, EAE development was not prevented by E2 treatment in chimeric mice that selectively expressed ERalpha in the systemic immune compartment. In conclusion, our data demonstrate that the beneficial effect of E2 on this autoimmune disease does not involve ERalpha signaling in blood-derived inflammatory cells, and indicate that ERalpha expressed in other tissues, such as CNS-resident microglia or endothelial cells, mediates this effect.

  8. Gender-dependent expression of alpha and beta estrogen receptors in human nontumor and tumor lung tissue.

    PubMed

    Fasco, Michael J; Hurteau, Gregory J; Spivack, Simon D

    2002-02-25

    Estrogen receptor (ER) expression in human lung has been understudied, particularly in light of its potential biological importance in the female lung cancer epidemic. Reverse transcription-polymerase chain reaction was used to probe mRNA expression of wild-type ERalpha and ERbeta and their splice variants in human bronchogenic tumor and adjacent nontumor specimens. In tumor tissue from 13 women and 13 men, ERalpha was expressed in 85% of women versus 15% in men [P=0.001]. ERbeta was expressed equally in tumors from women versus men [92% vs. 69%, P=ns]. Both ERalpha and beta forms were expressed simultaneously in the lung tumors of 77% of women versus 15% of men [P=0.005]. Among adjacent nontumor lung specimens, 31% of the women expressed ERalpha mRNA versus 0% of men [P=0.101], and 39% of women expressed ERbeta mRNA versus 31% of men [P=ns]; only one woman and no men expressed both ERalpha and beta in nontumor tissue. Females expressed ERalpha [P=0.017], ERbeta [P=0.013], and ERalpha+beta [P=0.002] more frequently in tumor versus nontumor tissue, whereas in males expression of ERalpha, beta and both alpha+beta was not clearly different for tumor versus nontumor tissue. In specimens expressing ERalpha mRNA, the transcript lacking exon 7 (delta7) was the major splice variant with varying contributions from the transcripts delta4, delta3+4, delta5 and others unidentified. Alternative splicing of ERbeta mRNA was observed, but not to as great an extent as for ERalpha mRNA. ERalpha promoter usage in tumors varied among individuals. When the ER receptors were co-expressed in tumors, ERalpha was quantitatively more abundant in the majority of cases than ERbeta. Within this small group of 26 patients, no correlation was found between age, smoking history, plasma nicotine, cotinine, estradiol concentrations or histopathologic type with tumor or nontumor estrogen receptor status of any type. However, several positive correlations imply that: (1) ERalpha expression occurs

  9. Measurement of the relative binding affinity of zearalenone, alpha-zearalenol and beta-zearalenol for uterine and oviduct estrogen receptors in swine, rats and chickens: an indicator of estrogenic potencies.

    PubMed

    Fitzpatrick, D W; Picken, C A; Murphy, L C; Buhr, M M

    1989-01-01

    1. The relative binding affinity of zearalenone, alpha-zearalenol, and beta-zearalenol for estrogen receptors was determined in the pig, rat and chicken. 2. Similar relative binding patterns were observed, with alpha-zearalenol exhibiting greater affinity than zearalenone and beta-zearalenol the least binding affinity in all species. 3. The relative binding affinity of alpha-zearalenol was greater in pig, than in rat and significantly greater than in chicken. 4. Interspecies differences in zearalenone sensitivity may be due to the binding affinity of alpha-zearalenol for estrogen receptors and differences in zearalenone metabolites formed.

  10. Estrogen receptor-beta and breast cancer: Translating biology into clinical practice

    PubMed Central

    Leung, Yuet-Kin; Lee, Ming-Tsung; Lam, Hung-Ming; Tarapore, Pheruza; Ho, Shuk-Mei

    2012-01-01

    Estrogen receptor (ER) β was discovered over a decade ago. The design of most studies on this receptor was based on knowledge of its predecessor, ERα. Although breast cancer (BCa) has been a main focus of ERβ research, its precise roles in breast carcinogenesis remain elusive. Data from in vitro models have not always matched those from observational or clinical studies. Several inherent factors may contribute to these discrepancies: a) several ERβ spliced variants are expressed at the protein level, and isoform-specific antibodies are unavailable for some variants; b) post-translational modifications of the receptor regulate receptor functions; c) the role of the receptor differs significantly depending on the type of ligands, cis-elements, and co-regulators that interact with the receptor; and d) the diversity of distribution of the receptor among intracellular organelles of BCa cells. This review addresses the gaps in knowledge in ERβ research as it pertains to BCa regarding the following questions: 1) is ERβ a tumor suppressor in BCa?; 2) do ERβ isoforms play differential roles in breast carcinogenesis?; 3) do nuclear signaling and extranuclear ERβ signaling differ in BCa?; 4) what are the consequences of post-translational modifications of ERβ in BCa?; 5) how do co-regulators and interacting proteins increase functional diversity of ERβ?; and 6) how do the types of ligand and regulatory cis-elements affect the action of ERβ in BCa? Insights gained from these key questions in ERβ research should help in prevention, diagnosis/prognosis, and treatment of BCa. PMID:22465878

  11. Modulation of vitellogenin synthesis through estrogen receptor beta-1 in goldfish (Carassius auratus) juveniles exposed to 17-{beta} estradiol and nonylphenol

    SciTech Connect

    Soverchia, L.; Ruggeri, B.; Palermo, F.; Mosconi, G.; Cardinaletti, G.; Scortichini, G.; Gatti, G.; Polzonetti-Magni, A.M. . E-mail: alberta.polzonetti@unicam.it

    2005-12-15

    Many synthetic chemicals, termed xenoestrogens, have been shown to interact as agonists with the estrogen receptor (ER) to elicit biological responses similar to those of natural hormones. To date, the regulation of vitellogenesis in oviparous vertebrates has been widely used for evaluation of estrogenic effects. Therefore, Carassius auratus juveniles were chosen as a fish model for studying the effects of estradiol-17{beta} and different concentrations (10{sup -6} and 10{sup -7} M) of 4-nonylphenol (4-NP) on the expression of liver ER{beta}-1 subtype; plasma vitellogenin and sex steroids (androgens and estradiol-17{beta}) were also evaluated together with the bioaccumulation process, through mass-spectrometry. C. auratus is a species widespread in the aquatic environment and, on the toxicological point of view, can be considered a good 'sentinel' species. Juveniles of goldfish were maintained in tanks with only tap water or water with different concentrations (10{sup -6} and 10{sup -7} M) of 4-nonylphenol (4-NP), or 10{sup -7} M of estradiol-17{beta}. After 3 weeks of treatment, animals were anesthetized within 5 min after capture, and blood was immediately collected into heparinized syringes by cardiac puncture and stored at -70 deg. C; the gonads were fixed, then frozen and stored at -70 deg. C; the whole fish, liver, and muscle tissues were harvested and immediately stored at -70 deg. C for molecular biology experiments and bioaccumulation measurements. The estrogenic effects of 4-NP were evidenced by the presence of plasma vitellogenin in juveniles exposed both to estradiol-17{beta} and the two doses of 4-NP; moreover, exposure to 4-NP also increased aromatization of androgens, as suggested by decreasing androgens and increasing estradiol-17{beta} plasma levels. The changes of these parameters were in agreement with the increasing transcriptional rate of ER{beta}-1 mRNA in the liver, demonstrating that both estradiol-17{beta} and 4-NP modulate the vitellogenin

  12. Benzopyrans as selective estrogen receptor beta agonists (SERBAs). Part 3: synthesis of cyclopentanone and cyclohexanone intermediates for C-ring modification.

    PubMed

    Richardson, Timothy I; Dodge, Jeffrey A; Durst, Gregory L; Pfeifer, Lance A; Shah, Jikesh; Wang, Yong; Durbin, Jim D; Krishnan, Venkatesh; Norman, Bryan H

    2007-09-01

    Benzopyrans are selective estrogen receptor (ER) beta agonists (SERBAs), which bind the ER subtypes alpha and beta in opposite orientations. Here we describe the syntheses of cyclopentanone and cyclohexanone intermediates for SAR studies of the C-ring on the benzopyran scaffold. Modification of the C-ring disrupts binding to ERalpha, thus improving ERbeta selectivity up to 100-fold. X-ray cocrystal structures confirm previously observed binding modes.

  13. Revisiting the neural role of estrogen receptor beta in male sexual behavior by conditional mutagenesis.

    PubMed

    Naulé, Lydie; Marie-Luce, Clarisse; Parmentier, Caroline; Martini, Mariangela; Albac, Christelle; Trouillet, Anne-Charlotte; Keller, Matthieu; Hardin-Pouzet, Hélène; Mhaouty-Kodja, Sakina

    2016-04-01

    Estradiol derived from neural aromatization of gonadal testosterone plays a key role in the perinatal organization of the neural circuitry underlying male sexual behavior. The aim of this study was to investigate the contribution of neural estrogen receptor (ER) β in estradiol-induced effects without interfering with its peripheral functions. For this purpose, male mice lacking ERβ in the nervous system were generated. Analyses of males in two consecutive tests with a time interval of two weeks showed an effect of experience, but not of genotype, on the latencies to the first mount, intromission, pelvic thrusting and ejaculation. Similarly, there was an effect of experience, but not of genotype, on the number of thrusts and mating length. Neural ERβ deletion had no effect on the ability of males to adopt a lordosis posture in response to male mounts, after castration and priming with estradiol and progesterone. Indeed, only low percentages of both genotypes exhibited a low lordosis quotient. It also did not affect their olfactory preference. Quantification of tyrosine hydroxylase- and kisspeptin-immunoreactive neurons in the preoptic area showed unaffected sexual dimorphism of both populations in mutants. By contrast, the number of androgen receptor- and ERα-immunoreactive cells was significantly increased in the bed nucleus of stria terminalis of mutant males. These data show that neural ERβ does not play a crucial role in the organization and activation of the neural circuitry underlying male sexual behavior. These discrepancies with the phenotype of global ERβ knockout models are discussed.

  14. Phylogenetic sequence analysis, recombinant expression, and tissue distribution of a channel catfish estrogen receptor beta

    USGS Publications Warehouse

    Xia, Zhenfang; Gale, William L.; Chang, Xiaotian; Langenau, David; Patino, Reynaldo; Maule, Alec G.; Densmore, Llewellyn D.

    2000-01-01

    An estrogen receptor β (ERβ) cDNA fragment was amplified by RT-PCR of total RNAextracted from liver and ovary of immature channel catfish. This cDNA fragment was used to screen an ovarian cDNA library made from an immature female fish. A clone was obtained that contained an open reading frame encoding a 575-amino-acid protein with a deduced molecular weight of 63.9 kDa. Maximum parsimony and Neighbor Joining analyses were used to generate a phylogenetic classification of channel catfish ERβ on the basis of 25 full-length teleost and tetrapod ER sequences. The consensus tree obtained indicated the existence of two major vertebrate ER subtypes, α and β. Within each subtype, and in accordance with established phylogenetic relationships, teleost and tetrapod ER were monophyletic confirming the results of a previous analysis (Z. Xiaet al., 1999, Gen. Comp. Endocrinol. 113, 360–368). Extracts of COS-7 cells transfectedwith channel catfish ERβ cDNA bound estrogen with high affinity (Kd = 0.21 nM) and specificity. The affinity of channel catfish ERβ for estrogen was higher than previously reported for channel catfish ERα. As determined by qualitative RT-PCR, the tissue distributions of ERα and ERβ were similar but not identical. Both ER subtypes were present in ovary and testis. ERα was found in all other tissues examined from juvenile and mature fish of both sexes. ERβ was also found in most tissues except, in most cases, whole blood and head kidney. Interestingly, the pattern of expression of ER subtypes in head kidney always corresponded to the pattern in whole blood. In conclusion, we isolated a channel catfish ERβ with ligand-binding affinity and tissue expression patterns different from ERα. Also, we confirmed the validity of our previously proposed general classification scheme for vertebrate ER into α and β subtypes and within each subtype, into teleost and tetrapod clades.

  15. Isoflavones made simple - genistein's agonist activity for the beta-type estrogen receptor mediates their health benefits.

    PubMed

    McCarty, Mark Frederick

    2006-01-01

    Soy isoflavones, the focus of much research and controversy, are often referred to as "weak estrogens". In fact, genistein is a relatively potent agonist for the recently characterized beta isoform of the estrogen receptor (ERbeta). The low nanomolar serum concentrations of unconjugated free genistein achieved with high-nutritional intakes of soy isoflavones are near the binding affinity of genistein for this receptor, but are about an order of magnitude lower than genistein's affinity for the "classical" alpha isoform of the estrogen receptor (ERalpha). Moreover, these concentrations are far too low to inhibit tyrosine kinases or topoisomerase II, in vitro activities of genistein often cited as potential mediators of its physiological effects. The thesis that these physiological effects are in fact mediated by ERbeta activation provides a satisfying rationale for genistein's clinical activities. Hepatocytes do not express ERbeta; this explains why soy isoflavones, unlike oral estrogen, neither modify serum lipids nor provoke the prothrombotic effects associated with increased risk for thromboembolic disorders. The lack of uterotrophic activity of soy isoflavones reflects the fact that ERalpha is the exclusive mediator of estrogen's impact in this regard. Vascular endothelium expresses both ERalpha and ERbeta, each of which has the potential to induce and activate nitric oxide synthase; this may account for the favorable influence of soy isoflavones on endothelial function in postmenopausal women and ovariectomized rats. The ERbeta expressed in osteoblasts may mediate the reported beneficial impact of soy isoflavones on bone metabolism. Suggestive evidence that soy-rich diets decrease prostate cancer risk, accords well with the observation that ERbeta appears to play an antiproliferative role in healthy prostate. In the breast, ERalpha promotes epithelial proliferation, whereas ERbeta has a restraining influence in this regard - consistent with the emerging view

  16. Estrogen receptor-beta colocalizes extensively with parvalbumin-labeled inhibitory neurons in the cortex, amygdala, basal forebrain, and hippocampal formation of intact and ovariectomized adult rats.

    PubMed

    Blurton-Jones, Mathew; Tuszynski, Mark H

    2002-10-21

    Estrogen has been reported to regulate the activity of gamma-aminobutyric acid (GABA)ergic interneurons within the hippocampus, basal forebrain, and hypothalamus of adult rodents. Although estrogen receptor-alpha bearing GABAergic interneurons have been identified previously, the neurotransmitter phenotype of cells that express the more recently characterized estrogen receptor-beta (ER-beta) has not been examined in vivo. We, therefore, have used fluorescent immunohistochemistry to further characterize the phenotype of ER-beta-bearing cells by double labeling for the GABAergic-associated calcium-binding protein, parvalbumin (PV). We find that a large proportion of ER-beta-immunoreactive cells within the cortex, amygdala, basal forebrain, and hippocampal formation of intact and ovariectomized (ovx) adult rats are PV-immunoreactive. Within the infralimbic, agranular insular, primary motor, parietal association, perirhinal, and lateral entorhinal cortices, an average of 95.6% +/- 0.8% (intact) and 94.5% +/- 1.4% (ovx) of all ER-beta-immunoreactive cells coexpress parvalbumin, and this proportion is strikingly similar across these diverse cortical regions. ER-beta/PV double-labeled cells represent 23.3% +/- 1.6% (intact) and 25.8% +/- 2.0% (ovx) of all PV-labeled cells within these regions. ER-beta/PV double-labeled cells are also observed within the lateral, accessory basal, and posterior cortical nuclei of the amygdala, and periamygdaloid cortex. Within the basal forebrain, 31.0% +/- 3.1% (intact) and 26.0% +/- 5.2 % (ovx) of ER-beta-immunoreactive cells coexpress PV. Almost all ER-beta-immunoreactive cells within the subiculum, a major output region of the hippocampal formation, double label for PV (intact = 97.2% +/- 2.8%; ovx = 100% +/- 0.0%). Thus, ER-beta exhibits extensive colocalization with a subclass of inhibitory neurons, suggesting a potential mechanism whereby estrogen can regulate neuronal excitability in diverse and broad brain regions by modulating

  17. Antimitotic activity of DY131 and the estrogen-related receptor beta 2 (ERRβ2) splice variant in breast cancer

    PubMed Central

    Heckler, Mary M.; Zeleke, Tizita Zewde; Divekar, Shailaja D.; Fernandez, Aileen I.; Tiek, Deanna M.; Woodrick, Jordan; Farzanegan, Alexander; Roy, Rabindra; Üren, Aykut; Mueller, Susette C.; Riggins, Rebecca B.

    2016-01-01

    Breast cancer remains a leading cause of cancer-related death in women, and triple negative breast cancer (TNBC) lacks clinically actionable therapeutic targets. Death in mitosis is a tumor suppressive mechanism that occurs in cancer cells experiencing a defective M phase. The orphan estrogen-related receptor beta (ERRβ) is a key reprogramming factor in murine embryonic and induced pluripotent stem cells. In primates, ERRβ is alternatively spliced to produce several receptor isoforms. In cellular models of glioblastoma, short form (ERRβsf) and beta2 (ERRβ2) splice variants differentially regulate cell cycle progression in response to the synthetic agonist DY131, with ERRβ2 driving arrest in G2/M. The goals of the present study are to determine the cellular function(s) of ligand-activated ERRβ splice variants in breast cancer and evaluate the potential of DY131 to serve as an antimitotic agent, particularly in TNBC. DY131 inhibits growth in a diverse panel of breast cancer cell lines, causing cell death that involves the p38 stress kinase pathway and a bimodal cell cycle arrest. ERRβ2 facilitates the block in G2/M, and DY131 delays progression from prophase to anaphase. Finally, ERRβ2 localizes to centrosomes and DY131 causes mitotic spindle defects. Targeting ERRβ2 may therefore be a promising therapeutic strategy in breast cancer. PMID:27363015

  18. Gender-Related Survival Differences Associated With Polymorphic Variants of Estrogen Receptor Beta (ERβ) in Patients with Metastatic Colon Cancer

    PubMed Central

    Press, Oliver A.; Zhang, Wu; Gordon, Michael A.; Yang, Dongyun; Haiman, Christopher A.; Azuma, Mizutomo; Iqbal, Syma; Lenz, Heinz-Josef

    2010-01-01

    Estrogen replacement therapy in women has demonstrated a protective effect in the development of colonic carcinomas. Gender-related differences in the development of colonic carcinomas have also been reported. Estrogen receptor beta (ERβ) is expressed in colon carcinomas and has demonstrated prognostic value in colon cancer patients. This study investigated an ERβ 3’ non-coding polymorphism associated with transcriptional activity to determine clinical outcome in patients with metastatic colon cancer. Genomic DNA from 318 metastatic colon cancer patients, 177 males and 141 females, were collected from 1992 to 2003. These patients were analyzed for CA repeat polymorphism of the ERβ gene. Gender-related survival differences were associated with an ERβ (CA)n repeat polymorphism (P for interaction=0.003, the likelihood ratio test). Female patients with any short <22 (CA)n repeat alleles had shorter overall survival compared to female patients that had both long ≥22 (CA)n repeat alleles. In the male patients the opposite overall survival difference was found. This study supports the role of an ERβ (CA)n repeat polymorphism as a prognostic marker in metastatic colon cancer; however, this prognostic factor had opposite implications based on gender. PMID:20548329

  19. Delay of postnatal maturation sensitizes the mouse prostate to testosterone-induced pronounced hyperplasia: protective role of estrogen receptor-beta.

    PubMed

    Savolainen, Saija; Pakarainen, Tomi; Huhtaniemi, Ilpo; Poutanen, Matti; Mäkelä, Sari

    2007-09-01

    The role of estrogens in the etiology of prostate cancer is controversial. To demonstrate the specific effects of estrogens and androgens on the development of the prostatic epithelial hyperplasia, we used luteinizing hormone receptor knockout mice (LuRKO), which are resistant to pituitary regulation mediated by luteinizing hormone, lack postnatal androgen production, and have rudimentary accessory sex glands, the growth of which can be induced with exogenous androgen replacement. This model is thus ideal for the investigation of direct hormonal effects on the prostate. Testosterone, but not 5alpha-dihydrotestosterone, replacement from 21 days of life for 8 weeks induced pronounced hyperplasia and inflammation in the prostates of LuRKO mice. Interestingly, 5alpha-dihydrotestosterone combined with 17beta-estradiol did not induce hyperplasia or inflammation, and treatments with inhibitors of estrogen action, aromatase inhibitor, and ICI 182780 further exacerbated testosterone-induced hyperplastic growth. However, the activation of estrogen receptor (ER)-beta with a specific agonist, DPN [2,3-bis(4-hydroxyphenol)-propionitrile], prevented the development of prostatic hyperplasia and inflammation in testosterone-treated LuRKO mice. Thus, it seems that in the presence of sufficient androgenic stimulation, it is the balance between ER-alpha- and ER-beta-mediated signaling that determines whether estrogens promote hyperplasia or protect the prostate against hyperplastic changes.

  20. Selective estrogen receptor-beta (SERM-beta) compounds modulate raphe nuclei tryptophan hydroxylase-1 (TPH-1) mRNA expression and cause antidepressant-like effects in the forced swim test.

    PubMed

    Clark, J A; Alves, S; Gundlah, C; Rocha, B; Birzin, E T; Cai, S-J; Flick, R; Hayes, E; Ho, K; Warrier, S; Pai, L; Yudkovitz, J; Fleischer, R; Colwell, L; Li, S; Wilkinson, H; Schaeffer, J; Wilkening, R; Mattingly, E; Hammond, M; Rohrer, S P

    2012-11-01

    Estrogen acts through two molecularly distinct receptors termed estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) which bind estradiol with similar affinities and mediate the effects of estrogen throughout the body. ERα plays a major role in reproductive physiology and behavior, and mediates classic estrogen signaling in such tissues as the uterus, mammary gland, and skeleton. ERβ, however, modulates estrogen signaling in the ovary, the immune system, prostate, gastrointestinal tract, and hypothalamus, and there is some evidence that ERβ can regulate ERα activity. Moreover, ERβ knockout studies and receptor distribution analyses in the CNS suggest that this receptor may play a role in the modulation of mood and cognition. In recent years several ERβ-specific compounds (selective estrogen receptor beta modulators; SERM-beta) have become available, and research suggests potential utility of these compounds in menopausal symptom relief, breast cancer prevention, diseases that have an inflammatory component, osteoporosis, cardiovascular disease, and inflammatory bowel disease, as well as modulation of mood, and anxiety. Here we demonstrate an antidepressant-like effect obtained using two SERM-beta compounds, SERM-beta1 and SERM-beta2. These compounds exhibit full agonist activity at ERβ in a cell based estrogen response element (ERE) transactivation assay. SERM-beta1 and 2 are non-proliferative with respect to breast as determined using the MCF-7 breast cancer cell-based assay and non-proliferative in the uterus as determined by assessing the effects of SERM-beta compounds on immature rat uterine weight and murine uterine weight. In vivo SERM-beta1 and 2 are brain penetrant and display dose dependent efficacy in the murine dorsal raphe assays for induction of tryptophan hydroxylase mRNA and progesterone receptor protein. These compounds show activity in the murine forced swim test and promote hippocampal neurogenesis acutely in rats. Taken

  1. Expression of estrogen receptor beta increases integrin alpha1 and integrin beta1 levels and enhances adhesion of breast cancer cells.

    PubMed

    Lindberg, Karolina; Ström, Anders; Lock, John G; Gustafsson, Jan-Ake; Haldosén, Lars-Arne; Helguero, Luisa A

    2010-01-01

    Estrogen effects on mammary gland development and differentiation are mediated by two receptors (ERalpha and ERbeta). Estrogen-bound ERalpha induces proliferation of mammary epithelial and cancer cells, while ERbeta is important for maintenance of the differentiated epithelium and inhibits proliferation in different cell systems. In addition, the normal breast contains higher ERbeta levels compared to the early stage breast cancers, suggesting that loss of ERbeta could be important in cancer development. Analysis of ERbeta-/- mice has consistently revealed reduced expression of cell adhesion proteins. As such, ERbeta is a candidate modulator of epithelial homeostasis and metastasis. Consequently, the aim of this study was to analyze estrogenic effects on adhesion of breast cancer cells expressing ERalpha and ERbeta. As ERbeta is widely found in breast cancer but not in cell lines, we used ERalpha positive T47-D and MCF-7 human breast cancer cells to generate cells with inducible ERbeta expression. Furthermore, the colon cancer cell lines SW480 and HT-29 were also used. Integrin alpha1 mRNA and protein levels increased following ERbeta expression. Integrin beta1-the unique partner for integrin alpha1-increased only at the protein level. ERbeta expression enhanced the formation of vinculin containing focal complexes and actin filaments, indicating a more adhesive potential. This was confirmed by adhesion assays where ERbeta increased adhesion to different extracellular matrix proteins, mostly laminin. In addition, ERbeta expression was associated to less cell migration. These results indicate that ERbeta affects integrin expression and clustering and consequently modulates adhesion and migration of breast cancer cells.

  2. Estrogenic effects of natural and synthetic compounds including tibolone assessed in Saccharomyces cerevisiae expressing the human estrogen alpha and beta receptors.

    PubMed

    Hasenbrink, Guido; Sievernich, André; Wildt, Ludwig; Ludwig, Jost; Lichtenberg-Fraté, Hella

    2006-07-01

    The human estrogen receptors (hER)alpha and hERbeta, differentially expressed and localized in various tissues and cell types, mediate transcriptional activation of target genes. These encode a variety of physiological reproductive and nonreproductive functions involved in energy metabolism, salt balance, immune system, development, and differentiation. As a step toward developing a screening assay for the use in applications where significant numbers of compounds or complex matrices need to be tested for (anti) estrogenic bioactivity, hERalpha and hERbeta were expressed in a genetically modified Saccharomyces cerevisiae strain, devoid of three endogenous xenobiotic transporters (PDR5, SNQ2, and YOR1). By using receptor-mediated transcriptional activation of the green fluorescent protein optimized for expression in yeast (yEGFP) as reporter 17 natural, comprising estrogens and phytoestrogens or synthetic compounds among which tibolone with its metabolites, gestagens, and antiestrogens were investigated. The reporter assay deployed a simple and robust protocol for the rapid detection of estrogenic effects within a 96-well microplate format. Results were expressed as effective concentrations (EC50) and correlated to other yeast based and cell line assays. Tibolone and its metabolites exerted clear estrogenic effects, though considerably less potent than all other natural and synthetic compounds. For the blood serum of two volunteers, considerable higher total estrogenic bioactivity than single estradiol concentrations as determined by immunoassay was found. Visualization of a hERalpha/GFP fusion protein in yeast revealed a sub cellular cytosolic localization. This study demonstrates the versatility of (anti) estrogenic bioactivity determination using sensitized S. cerevisiae cells to assess estrogenic exposure and effects.

  3. Sensitivity of a Tier I screening battery compared to an in utero exposure for detecting the estrogen receptor agonist 17 beta-estradiol.

    PubMed

    O'Connor, J C; Frame, S R; Biegel, L B; Cook, J C; Davis, L G

    1998-08-01

    A Tier I screening battery for detecting endocrine active compounds (EACs) has been evaluated for its ability to identify 17 beta-estradiol, a pure estrogen receptor agonist. In addition, the responses obtained with the Tier I battery were compared to the responses obtained from F1 generation rats from a 90-day/one-generation reproduction study with 17 beta-estradiol in order to characterize the sensitivity of the Tier I battery against the sensitivity of an in utero exposure for detecting EACs. The Tier I battery incorporates two short-term in vivo tests (5-day ovariectomized female battery; 15-day intact male battery) and an in vitro yeast transactivation system (YTS) for identifying compounds that alter endocrine homeostasis. The Tier I female battery consists of traditional uterotrophic endpoints coupled with biochemical and hormonal endpoints. It is designed to identify compounds that are estrogenic/antiestrogenic or modulate dopamine levels. The Tier I male battery consists of organ weights coupled with microscopic evaluations and a comprehensive hormonal assessment. It is designed to identify compounds that have the potential to act as agonists or antagonists to the estrogen, androgen, progesterone, or dopamine receptor; steroid biosynthesis inhibitors (aromatase, 5 alpha-reductase, and testosterone biosynthesis); or compounds that alter thyroid function. The YTS is designed to identify compounds that bind to steroid hormone receptors (estrogen, androgen, and progesterone) and activate gene transcription. The profile generated for 17 beta-estradiol was characteristic of the responses expected with a pure estrogen receptor agonist. In the female battery, responses to 17 beta-estradiol included increases in uterine fluid imbibition, uterine weight, estrus conversion, uterine stromal cell proliferation, uterine epithelial cell height, uterine progesterone receptor content, serum prolactin and estradiol levels, and decreases in uterine estrogen receptor content

  4. HOMOLOGY MODELING OF THE ESTROGEN RECEPTOR SUBTYPE BETA (ER-BETA) AND CALCULATION OF LIGAND BINDING AFFINITIES. (R826133)

    EPA Science Inventory

    Abstract

    Estrogen is a steroid hormone playing critical roles in physiological processes such as sexual differentiation and development, female and male reproductive processes, and bone health. Numerous natural and synthetic environmental compounds have been shown capa...

  5. Polymorphism analysis in estrogen receptors alpha and beta genes and their association with infertile population in Pakistan

    PubMed Central

    Liaqat, Sinha; Hasnain, Shahida; Muzammil, Saima; Hayat, Sumreen

    2015-01-01

    Studies on polymorphism of estrogen receptor (ESR) alpha and beta genes have been mostly implicated in infertility, but the results have been controversial due to lack of comprehensive data. The present study focused on association of ESR genes with both male and female infertility. In ESRα, PvuII (rs2234693) and XbaI (rs9340799) were studied while in ESRβ gene, risk of infertility was determined for silent G/A RsaI (rs1256049) polymorphism. Total 124 subjects (74 cases and 50 controls) were part of this study having primary infertility. Restriction fragment length polymorphism (RFLP) was performed with PvuII, XbaI and RsaI to determine polymorphism. Correlation between age and follicle stimulating hormone (FSH) of cases and controls was determined and no association was found between infertility and FSH hormone. Heterozygous AG genotype of XbaI polymorphism (P= 2.505e-06) and heterozygous TC genotype (P= 0.00003) in PvuII polymorphism were strongly associated with risk of infertility. In ESRβ gene, there was lack of polymorphism for RsaI in our population as all subjects were homozygous (GG). Haplotype frequencies showed that XbaI and PvuII polymorphisms are in strong linkage disequilibrium. This study shows that in our population XbaI and PvuII polymorphisms of ESRα are associated with risk of infertility. PMID:27065769

  6. Gene cloning, homology comparison and analysis of the main functional structure domains of beta estrogen receptor in Jining Gray goat.

    PubMed

    Liu, Hai-gang; Li, Hong-mei; Wang, Shu-ying; Huang, Li-bo; Guo, Hui-jun

    2014-08-01

    To clarify the molecular evolution and characteristic of beta estrogen receptor (ERβ) gene in Jining Gray goat in China, the entire ERβ gene from Jining Gray goat ovary was amplified, identified and sequenced, and the gene sequences were compared with those of other animals. Functional structural domains and variations in DNA binding domains (DBD) and ligand binding domains (LBD) between Jining Gray goat and Boer goat were analyzed. The results indicate that the ERβ gene in Jining Gray goat includes a 1584bp sequence with a complete open-reading-frame (ORF), encoding a 527 amino acid (aa) receptor protein. Compared to other species, the nucleotide homology is 73.9-98.9% and the amino acid homology is 79.5-98.5%. The main antigenic structural domains lie from the 97th aa to the 286th aa and from the 403rd aa to the 527th aa. The hydrophilicity and the surface probability of the structural domains are distributed throughout a range of amino acids. There are two different amino acids in the DBD and three different amino acids in the LBD between Jining Gray and Boer goats, resulting in dramatically different spatial structures for ERβ protein. These differences may explain the different biological activities of ERβ between the two goat species. This study firstly acquired the whole ERβ gene sequence of Jining Gray goat with a complete open reading frame, and analyzed its gene evolutionary relationship and predicted its mainly functional structural domains, which may very help for further understanding the genome evolution and gene diversity of goat ERβ.

  7. Factors associated with estrogen receptors-alpha (ER-alpha) and -beta (ER-beta) and progesterone receptor abundance in obese and non obese pre- and post-menopausal women.

    PubMed

    Meza-Muñoz, Dalia Edith; Fajardo, Martha E; Pérez-Luque, Elva Leticia; Malacara, Juan Manuel

    2006-06-01

    There is scarce information about the factors associated with estrogen receptors (ER) at menopause. In 113 volunteers pre- and post-menopausal healthy women, grouped as with and without obesity, estrogen receptors-alpha and -beta, and progesterone receptor (PR) were measured by immunohistochemistry in skin punch biopsies obtained from the external gluteal area. In pre-menopausal women, biopsies and a blood sample were performed between days 7 and 14 of the cycle. Serum hormone levels were measured by immunoradiometric assay or radioimmunoassay. After menopause, ER and PR amounts decreased significantly. At pre-menopause, obese women had lower PR levels than non obese (P<.006). In the post-menopausal group, obese women showed higher ER-alpha (P<.03) and ER-beta (P<.02) levels than the non obese group. In the analysis of factors associated with the amount of steroid receptors for the total group, log[ER-alpha], log[ER-beta], and log[PR] were associated with age (P<.002, <.005, and <.004, respectively). The log[ER-alpha] was also associated with log[FSH] (P<.0008); meanwhile, the log[PR] showed a marginal correlation with log[FSH]. In pre-menopausal women no factor associated with any of the three receptors was found. In post-menopausal women log[ER-alpha] was associated with log[estrone] and log[DHEAS] (P<.003 and <.02, respectively). log[PR] was associated with BMI (P<.002), years since menopause (P<.05), and log[DHEAS] (P<.003). We concluded that ER and PR diminish sharply at post-menopause. At this stage the amount of receptors depends on several factors such as BMI, years since menopause, and androgen precursors.

  8. (I-125) 17. cap alpha. -Iodovinyl 11. beta. -methoxyestradiol: in vivo and in vitro properties of a high-affinity estrogen-receptor radiopharmaceutical

    SciTech Connect

    Jagoda, E.M.; Gibson, R.E.; Goodgold, H.; Ferreira, N.; Francis, B.E.; Reba, R.C.; Rzeszotarski, W.J.; Eckelman, W.C.

    1984-04-01

    17 ..cap alpha..-(/sup 125/I)Iodovinyl 11 ..beta..-methoxyestradiol ((I-125)MIVE/sub 2/) has been prepared with high specific activity (155-2000 Ci/mmol) and a high affinity for the estrogen receptor. In vivo distribution studies using immature rats result in high levels of activity in the uterus (20-30% dose/g) with uterus-to-plasma ratios on the order of 68 to 100. Peak activity in the uterus is obtained between 2 and 4 hr, and by 6 hr 50% of the activity has washed out. The radioactive labeling of MIVE/sub 2/ is sufficiently rapid so that (I-123)MIVE/sub 2/ has been synthesized and is currently in clinical trials. These results suggest that MIVE/sub 2/ would be an excellent agent for the study of estrogen receptors in vivo and in vitro.

  9. Estrogen receptor beta rs1271572 polymorphism and invasive ovarian carcinoma risk: pooled analysis within the Ovarian Cancer Association Consortium.

    PubMed

    Lurie, Galina; Wilkens, Lynne R; Thompson, Pamela J; Shvetsov, Yurii B; Matsuno, Rayna K; Carney, Michael E; Palmieri, Rachel T; Wu, Anna H; Pike, Malcolm C; Pearce, Celeste L; Menon, Usha; Gentry-Maharaj, Aleksandra; Gayther, Simon A; Ramus, Susan J; Whittemore, Alice S; McGuire, Valerie; Sieh, Weiva; Pharoah, Paul D P; Song, Honglin; Gronwald, Jacek; Jakubowska, Anna; Cybulski, Cezary; Lubinski, Jan; Schildkraut, Joellen M; Berchuck, Andrew; Krüger Kjær, Susanne; Høgdall, Estrid; Fasching, Peter A; Beckmann, Matthias W; Ekici, Arif B; Hein, Alexander; Chenevix-Trench, Georgia; Webb, Penelope M; Beesley, Jonathan; Goodman, Marc T

    2011-01-01

    The association of ovarian carcinoma risk with the polymorphism rs1271572 in the estrogen receptor beta (ESR2) gene was examined in 4946 women with primary invasive ovarian carcinoma and 6582 controls in a pooled analysis of ten case-control studies within the Ovarian Cancer Association Consortium (OCAC). All participants were non-Hispanic white women. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression adjusted for site and age. Women with the TT genotype were at increased risk of ovarian carcinoma compared to carriers of the G allele (OR = 1.10; 95%; CI: 1.01-1.21; p = 0.04); the OR was 1.09 (CI: 0.99-1.20; p = 0.07) after excluding data from the center (Hawaii) that nominated this SNP for OCAC genotyping A stronger association of rs1271572 TT versus GT/GG with risk was observed among women aged ≤50 years versus older women (OR = 1.35; CI: 1.12-1.62; p = 0.002; p for interaction = 0.02) that remained statistically significant after excluding Hawaii data (OR = 1.34; CI: 1.11-1.61; p = 0.009). No heterogeneity of the association was observed by study, menopausal status, gravidity, parity, use of contraceptive or menopausal hormones, tumor histological type, or stage at diagnosis. This pooled analysis suggests that rs1271572 might influence the risk of ovarian cancer, in particular among younger women.

  10. Agonistic behavior in males and females: effects of an estrogen receptor beta agonist in gonadectomized and gonadally intact mice

    PubMed Central

    Allen, Amy E. Clipperton; Cragg, Cheryl L.; Wood, Alexis J.; Pfaff, Donald W.; Choleris, Elena

    2010-01-01

    Summary Affiliative and agonistic social interactions are mediated by gonadal hormones. Research with estrogen receptor alpha (ERα) or beta (ERβ) knockout (KO) mice show that long-term inactivation of ERα decreases, while inactivation of ERβ increases, male aggression. Opposite effects were found in female αERKO and βERKO mice. The role of acute activation of ERα or ERβ in the agonistic responses of adult non-KO mice is unknown. We report here the effects of the ERβ selective agonist WAY-200070 on agonistic and social behavior in gonadally intact and gonadectomized (gonadex) male and female CD-1 mice towards a gonadex, same-sex intruder. All 15 min resident-intruder tests were videotaped for comprehensive behavioral analysis. Separate analyses assessed: 1) effects of WAY-200070 on each sex and gonadal condition; 2) differences between sexes, and between gonadally intact and gonadex mice, in untreated animals. Results show that in gonadally intact male and female mice WAY-200070 increased agonistic behaviors such as pushing down and aggressive grooming, while leaving attacks unaffected. In untreated mice, males attacked more than females, and gonadex animals showed less agonistic behavior than same-sex, gonadally intact mice. Overall, our detailed behavioral analysis suggested that in gonadally intact male and female mice, ERβ mediates patterns of agonistic behavior that are not directly involved in attacks. This suggests that specific aspects of aggressive behavior are acutely mediated by ERβ in adult mice. Our results also showed that, in resident-intruder tests, female mice spend as much time in intrasexual agonistic interactions as males, but use agonistic behaviors that involve extremely low levels of direct attacks. This non-attack aggression in females is increased by acute activation of ERβ. Thus, acute activation of ERβ similarly mediates agonistic behavior in adult male and female CD-1 mice. PMID:20129736

  11. High-affinity binding of (/sup 3/H)estradiol-17 beta by an estrogen receptor in the liver of the turtle

    SciTech Connect

    Ho, S.M.; Fehrer, S.; Yu, M.; Liang, L.C.; Press, D.

    1988-06-01

    Specific (3H)estradiol-17 beta ((3H)E2) binding activity (EBA) with characteristics of an estrogen receptor (ER) was demonstrated in cytosols and nuclear extracts of the female turtle, Chrysemys picta. Three different receptor assays (dextran-coated charcoal assay, hydroxylapatite batch procedure, and DNA-cellulose chromatography) were evaluated in terms of their applicability in analyzing large numbers of samples. For the measurement of cytosolic EBA, the hydroxylapatite batch procedure was found to be the most reliable assay. On the other hand, the dextran-coated charcoal assay was found to be the most appropriate method for the measurement of nuclear EBA. Turtle hepatic EBA binds (3H)E2 with high affinity (cytosolic, 17.4 +/- 2.8 X 10(9) M-1; nuclear, 17.7 +/- 1.9 X 10(9) M-1), limited capacity (cytosolic, 133.7 +/- 4.6 fmol/g tissue; nuclear, 81.1 +/- 9.0 fmol/g tissue), and strict steroid specificity. The EBA bound natural estrogens (E2, estrone, estriol) as well as the nonsteroidal estrogen, diethylstilbestrol, but exhibited little affinity for androgens, progesterone, or corticosterone. The turtle hepatic EBA resembled mammalian and avian ERs in terms of binding characteristics; however, unlike mammalian and avian ERs it was shown to be heat-labile. Incubation at 30 degrees caused rapid loss of (3H)E2 binding activity in both cytosolic and nuclear fractions. The exchange between (3H)E2 and the endogenously bound estrogen was slow at 4 and 15 degrees, but the exchange process was facilitated in the presence of the chaotropic salt, NaSCN. Establishment of quantitation methods for both cytosolic and nuclear forms of EBA will enable future investigation of the mechanism and regulation of estrogen action in the liver of this turtle species.

  12. Estrogen receptors in breast carcinoma.

    PubMed

    Huaman, A

    1979-11-01

    On the basis of estrogen receptor assays, breast carcinomas are presently classified as estrogen-dependent tumors, which respond to endocrine therapy, and autonomous tumors, for which endocrine therapy is useless. This paper presents a short review of the biochemical principles of estrogen dependence, the procedures used to determine estrogen receptors, and the clinical applications of the findings of these assay procedures. Biobhemically, the estroogen dependence of normal breast cells is explained as a biochemical reaction occurring between the circulating estradiol and the breast cell, which occurs in 3 steps: 1) circulating estradiol penetrates the cellular membrane by passive diffusion, followed by 2) combining of estradiol with the estrogen-binding protein (estrophilin) and formation of an estrogen receptor complex which undergoes activation and translocation into the nucleus, to result in 3) the activated steroid receptor which combines with the nuclear charomatin and stimulates ribonucleic acid synthesis for the formation of estradiol binding proteins or estradiol receptors. The cytosol method of Wittliff et al. is described in brief and entails radioactive competitive analysis; the other available laboratory procedure is immunofluorescence of tumor sections. Quantification of estrogen receptor content can be used clinically to decide on ablative endocrine therapy, to determine the effectiveness of anti-estrogen administration, to determine the primary site of metastatic carcinoma, and as a screenng device.

  13. Selective Estrogen Receptor Modulators

    PubMed Central

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are now being used as a treatment for breast cancer, osteoporosis and postmenopausal symptoms, as these drugs have features that can act as an estrogen agonist and an antagonist, depending on the target tissue. After tamoxifen, raloxifene, lasofoxifene and bazedoxifene SERMs have been developed and used for treatment. The clinically decisive difference among these drugs (i.e., the key difference) is their endometrial safety. Compared to bisphosphonate drug formulations for osteoporosis, SERMs are to be used primarily in postmenopausal women of younger age and are particularly recommended if there is a family history of invasive breast cancer, as their use greatly reduces the incidence of this type of cancer in women. Among the above mentioned SERMs, raloxifene has been widely used in prevention and treatment of postmenopausal osteoporosis and vertebral compression fractures, and clinical studies are now underway to test the comparative advantages of raloxifene with those of bazedoxifene, a more recently developed SERM. Research on a number of adverse side effects of SERM agents is being performed to determine the long-term safety of this class of compouds for treatment of osteoporosis. PMID:27559463

  14. Intracoronary genistein acutely increases coronary blood flow in anesthetized pigs through beta-adrenergic mediated nitric oxide release and estrogenic receptors.

    PubMed

    Grossini, Elena; Molinari, Claudio; Mary, David A S G; Uberti, Francesca; Caimmi, Philippe Primo; Surico, Nicola; Vacca, Giovanni

    2008-05-01

    Various studies have suggested that the phytoestrogen genistein has beneficial cardioprotective and vascular effects. However, there has been scarce information regarding the primary effect of genistein on coronary blood flow and its mechanisms including estrogen receptors, autonomic nervous system, and nitric oxide (NO). The present study was planned to determine the primary effect of genistein on coronary blood flow and the mechanisms involved. In anesthetized pigs, changes in left anterior descending coronary artery caused by intracoronary infusion of genistein at constant heart rate and arterial pressure were assessed using ultrasound flowmeters. In 25 pigs, genistein infused at 0.075 mg/min increased coronary blood flow by about 16.3%. This response was graded in a further five pigs by increasing the infused dose of the genistein between 0.007 and 0.147 mg/min. In the 25 pigs, blockade of cholinergic receptors (iv atropine; five pigs) and alpha-adrenergic receptors (iv phentolamine; five pigs) did not abolish the coronary response to genistein, whose effects were prevented by blockade of beta(2)-adrenergic receptors (iv butoxamine; five pigs), nitric oxide synthase (intracoronary N(omega)-nitro-L-arginine methyl ester; five pigs) and estrogenic receptors (ERs; ERalpha/ERbeta; intracoronary fulvestrant; five pigs). In porcine aortic endothelial cells, genistein induced the phosphorylation of endothelial nitric oxide synthase and NO production through ERK 1/2, Akt, and p38 MAPK pathways, which was prevented by the concomitant treatment by butoxamine and fulvestrant. In conclusion, genistein primarily caused coronary vasodilation the mechanism of which involved ERalpha/ERbeta and the release of NO through vasodilatory beta(2)-adrenoreceptor effects.

  15. Synthesis of a beta-estradiol-biotin chimera that potently heterodimerizes estrogen receptor and streptavidin proteins in a yeast three-hybrid system.

    PubMed

    Hussey, Stephen L; Muddana, Smita S; Peterson, Blake R

    2003-04-02

    Small molecules that dimerize proteins in living cells provide powerful probes of biological processes and have potential as tools for the identification of protein targets of natural products. We synthesized 7-alpha-substituted derivatives of beta-estradiol tethered to the natural product biotin to regulate heterodimerization of estrogen receptor (ER) and streptavidin (SA) proteins expressed as components of a yeast three-hybrid system. Addition of an estradiol-biotin chimera bearing a 19-atom linker to yeast expressing DNA-bound ER-alpha or ER-beta LexA fusion proteins and wild-type SA protein fused to the B42 activation domain activated reporter gene expression by as much as 450-fold in vivo (10 muM ligand). Comparative analysis of lower affinity Y43A (biotin Kd approximately 100 pM) and W120A (biotin Kd approximately 100 nM) mutants of SA indicated that moderate affinity interactions can be readily detected with this system. Comparison of a 7-alpha-substituted estradiol-biotin chimera with a structurally similar dexamethasone-biotin chimera revealed that yeast expressing ER proteins can detect cognate ligands with up to 5-fold greater potency and 70-fold higher activity than yeast expressing analogous glucocorticoid receptor (GR) proteins. This approach may facilitate the identification of protein targets of biologically active small molecules screened against genetically encoded libraries of proteins expressed in yeast three-hybrid systems.

  16. Estrogen receptor signaling during vertebrate development

    PubMed Central

    Bondesson, Maria; Hao, Ruixin; Lin, Chin-Yo; Williams, Cecilia; Gustafsson, Jan-Åke

    2014-01-01

    Estrogen receptors are expressed and their cognate ligands produced in all vertebrates, indicative of important and conserved functions. Through evolution estrogen has been involved in controlling reproduction, affecting both the development of reproductive organs and reproductive behavior. This review broadly describes the synthesis of estrogens and the expression patterns of aromatase and the estrogen receptors, in relation to estrogen functions in the developing fetus and child. We focus on the role of estrogens for development of reproductive tissues, as well as non-reproductive effects on the developing brain. We collate data from human, rodent, bird and fish studies and highlight common and species-specific effects of estrogen signaling on fetal development. Morphological malformations originating from perturbed estrogen signaling in estrogen receptor and aromatase knockout mice are discussed, as well as the clinical manifestations of rare estrogen receptor alpha and aromatase gene mutations in humans. PMID:24954179

  17. Phosphorylation of human estrogen receptor-beta at serine 105 inhibits breast cancer cell migration and invasion.

    PubMed

    Lam, Hung-Ming; Suresh Babu, C V; Wang, Jiang; Yuan, Yong; Lam, Ying-Wai; Ho, Shuk-Mei; Leung, Yuet-Kin

    2012-07-06

    Multiple phosphorylation sites on the human estrogen receptor (hER)α were identified and shown to influence mammary carcinogenesis. In contrast, functional phosphorylation sites of hERβ have yet to be experimentally identified and validated. Here, using mass spectrometry, we uncovered three serines (S75, S87, and S105) in the N-terminus of hERβ as targets of ERK1/2 and p38 kinases. We raised a specific antibody against phosphorylated S105 (pS105) and demonstrated that this site was endogenously phosphorylated in MDA-MB-231 and BT-474 cells. A phospho-mimetic mutant generated from hERβ1 was found to exhibit higher transactivation activity than hERβ1. Ectopic expression of this mutant inhibited cell migration and invasion, but did not affect cell growth and cell-cycle progression in these cell models. In breast cancer specimens, pS105-hERβ immunoreactivity was detected with a higher prevalence and intensity than that of hERβ1. These results underscore the functional importance of the first experimentally identified hERβ-phosphorylation site in breast cancer.

  18. Functional characterization of estrogen receptor subtypes, ER{alpha} and ER{beta}, mediating vitellogenin production in the liver of rainbow trout

    SciTech Connect

    Leanos-Castaneda, Olga Kraak, Glen van der

    2007-10-15

    The estrogen-dependent process of vitellogenesis is a key function on oviparous fish reproduction and it has been widely used as an indicator of xenoestrogen exposure. The two estrogen receptor (ER) subtypes, ER{alpha} and ER{beta}, are often co-expressed in the liver of fish. The relative contribution of each ER subtype to modulate vitellogenin production by hepatocytes was studied using selected compounds known to preferentially interact with specific ER subtypes: propyl-pyrazole-triol (PPT) an ER{alpha} selective agonist, methyl-piperidino-pyrazole (MPP) an ER{alpha} selective antagonist, and diarylpropionitrile (DPN) an ER{beta} selective agonist. First, the relative binding affinity of the test compounds to estradiol for rainbow trout hepatic nuclear ER was determined using a competitive ligand binding assay. All the test ligands achieved complete displacement of specific [{sup 3}H]-estradiol binding from the nuclear ER extract. This indicates that the test ligands have the potential to modify the ER function in the rainbow trout liver. Secondly, the ability of the test compounds to induce or inhibit vitellogenin production by primary cultures of rainbow trout hepatocytes was studied. Estradiol and DPN were the only compounds that induced a dose-dependent increase on vitellogenin synthesis. The lack of vitellogenin induction by PPT indicates that ER{alpha} could not have a role on this reproductive process whereas the ability of DPN to induce vitellogenin production supports the participation of ER{beta}. In addition, this hypothesis is reinforced by the results obtained from MPP plus estradiol. On one hand, the absence of suppressive activity of MPP in the estradiol-induced vitellogenin production does not support the participation of ER{alpha}. On the other hand, once blocked ER{alpha} with MPP, the only manifestation of agonist activity of estradiol would be achieved via ER{beta}. In conclusion, the present results indicate that vitellogenin production is

  19. DNA Repair, Redox Regulation and Modulation of Estrogen Receptor Alpha Mediated Transcription

    ERIC Educational Resources Information Center

    Curtis-Ducey, Carol Dianne

    2009-01-01

    Interaction of estrogen receptor [alpha] (ER[alpha]) with 17[beta]-estradiol (E[subscript 2]) facilitates binding of the receptor to estrogen response elements (EREs) in target genes, which in turn leads to recruitment of coregulatory proteins. To better understand how estrogen-responsive genes are regulated, our laboratory identified a number of…

  20. Long-Term Estrogen Receptor Beta Agonist Treatment Modifies the Hippocampal Transcriptome in Middle-Aged Ovariectomized Rats

    PubMed Central

    Sárvári, Miklós; Kalló, Imre; Hrabovszky, Erik; Solymosi, Norbert; Rodolosse, Annie; Liposits, Zsolt

    2016-01-01

    Estradiol (E2) robustly activates transcription of a broad array of genes in the hippocampal formation of middle-aged ovariectomized rats via estrogen receptors (ERα, ERβ, and G protein-coupled ER). Selective ERβ agonists also influence hippocampal functions, although their downstream molecular targets and mechanisms are not known. In this study, we explored the effects of long-term treatment with ERβ agonist diarylpropionitrile (DPN, 0.05 mg/kg/day, sc.) on the hippocampal transcriptome in ovariectomized, middle-aged (13 month) rats. Isolated hippocampal formations were analyzed by Affymetrix oligonucleotide microarray and quantitative real-time PCR. Four hundred ninety-seven genes fulfilled the absolute fold change higher than 2 (FC > 2) selection criterion. Among them 370 genes were activated. Pathway analysis identified terms including glutamatergic and cholinergic synapse, RNA transport, endocytosis, thyroid hormone signaling, RNA degradation, retrograde endocannabinoid signaling, and mRNA surveillance. PCR studies showed transcriptional regulation of 58 genes encoding growth factors (Igf2, Igfb2, Igf1r, Fgf1, Mdk, Ntf3, Bdnf), transcription factors (Otx2, Msx1), potassium channels (Kcne2), neuropeptides (Cck, Pdyn), peptide receptors (Crhr2, Oprm1, Gnrhr, Galr2, Sstr1, Sstr3), neurotransmitter receptors (Htr1a, Htr2c, Htr2a, Gria2, Gria3, Grm5, Gabra1, Chrm5, Adrb1), and vesicular neurotransmitter transporters (Slc32a1, Slc17a7). Protein-protein interaction analysis revealed networking of clusters associated with the regulation of growth/troph factor signaling, transcription, translation, neurotransmitter and neurohormone signaling mechanisms and potassium channels. Collectively, the results reveal the contribution of ERβ-mediated processes to the regulation of transcription, translation, neurogenesis, neuromodulation, and neuroprotection in the hippocampal formation of ovariectomized, middle-aged rats and elucidate regulatory channels responsible for

  1. Estrogen receptor beta and truncated variants enhance the expression of transfected MMP-1 promoter constructs in response to specific mechanical loading

    PubMed Central

    2014-01-01

    Background Joint diseases such as osteoarthritis (OA) predominantly afflict post-menopausal women, suggesting a pertinent role for female hormones. Estrogen receptor beta (ER-β) has been detected in connective tissues of the knee joint suggesting that these tissues are responsive to the hormone estrogen. Matrix metalloproteinase-1 (MMP-1) activity contributes to cartilage degradation, a key factor leading to OA development in synovial joints. Two polymorphic forms of MMP-1 exist due to a deletion/insertion of the guanine residue in the promoter, and the 2G allelic variant of MMP-1 exhibits more activity than the 1G allele. Previous studies have demonstrated that the polymorphic forms of the human MMP-1 are influenced by the modulating effects of estrogen receptor isoforms. In addition to hormonal influences, physiological factors such as altered mechanical loading are also contributory features of OA. In the present study, the combined influence of biomechanical and hormonal variables on the activity of MMP-1 isoforms was evaluated. We hypothesized that the combined effects of ER-β and sheer stress will differentially activate the two allelic forms of MMP-1 in a hormone-independent manner. Methods HIG-82 synoviocytes were transiently transfected with 1G or 2G alleles (±) ER-β and subjected to either shear or equibiaxial stress. Next, 1G/2G promoter activity was measured to determine the combined influence of physiological stimuli. Truncated ER-β constructs were used to determine the importance of different domains of ER-β on 1G/2G activation. Results The 2G allele exhibited a constitutively higher activity than the 1G allele, which was further increased when the transfected cells were subject to shear stress, but not equibiaxial stress. Moreover, the combination of ER-β and shear stress further increased the activity levels of the 1G/2G allelic variants. Additionally, select AF-2 truncated ER-β variants led to increased activity levels for the 2G allele

  2. Modification of female and male social behaviors in estrogen receptor beta knockout mice by neonatal maternal separation

    PubMed Central

    Tsuda, Mumeko C.; Yamaguchi, Naoko; Nakata, Mariko; Ogawa, Sonoko

    2014-01-01

    Maternal separation (MS) is an animal model mimicking the effects of early life stress on the development of emotional and social behaviors. Recent studies revealed that MS stress increased social anxiety levels in female mice and reduced peri-pubertal aggression in male mice. Estrogen receptor (ER) β plays a pivotal role in the regulation of stress responses and anxiety-related and social behaviors. Behavioral studies using ERβ knockout (βERKO) mice reported increased social investigation and decreased social anxiety in βERKO females, and elevated aggression levels in βERKO males compared to wild-type (WT) mice. In the present study, using βERKO and WT mice, we examined whether ERβ contributes to MS effects on anxiety and social behaviors. βERKO and WT mice were separated from their dam daily (4 h) from postnatal day 1–14 and control groups were left undisturbed. First, MS and ERβ gene deletion individually increased anxiety-related behaviors in the open field test, but only in female mice. Anxiety levels were not further modified in βERKO female mice subjected to MS stress. Second, βERKO female mice showed higher levels of social investigation compared with WT in the social investigation test and long-term social preference test. However, MS greatly reduced social investigation duration and elevated number of stretched approaches in WT and βERKO females in the social investigation test, suggesting elevated levels of social anxiety in both genotypes. Third, peri-pubertal and adult βERKO male mice were more aggressive than WT mice as indicated by heightened aggression duration. On the other hand, MS significantly decreased aggression duration in both genotypes, but only in peri-pubertal male mice. Altogether, these results suggest that βERKO mice are sensitive to the adverse effects of MS stress on subsequent female and male social behaviors, which could then have overrode the ERβ effects on female social anxiety and male aggression. PMID:25228857

  3. A systematic review of the relationship between polymorphic sites in the estrogen receptor-beta (ESR2) gene and breast cancer risk.

    PubMed

    Yu, Ke-Da; Rao, Nan-Yan; Chen, Ao-Xiang; Fan, Lei; Yang, Chen; Shao, Zhi-Ming

    2011-02-01

    The estrogen signal is mediated by the estrogen receptor (ER). The specific role of ER-beta, a second ER, in breast carcinogenesis is not known. A number of association studies have been carried out to investigate the relationship between polymorphic sites in the ESR2 gene and breast cancer risk, however, the results are inconsistent. We searched PubMed, Medline, and Web of Science database (updated to 10 January 2010) and identified 13 relevant case-control studies, and approximately 28 single-nucleotide polymorphisms (SNPs) and one micro-satellite marker were reported in the literature. The median number of study subjects was 776 (range 158-13,550). Three genetic variants [(CA)n, rs2987983, and rs4986938] showed significant overall associations with breast cancer, and rs4986938 was reported twice. Because rs4986938 and rs1256049 were the most extensively studied polymorphisms, we subsequently conducted a meta-analysis to evaluate their relationship with breast cancer risk (9 studies of 10,837 cases and 16,021 controls for rs4986938; 8 studies of 11,652 cases and 15,726 controls for rs1256049). For rs4986938, the women harboring variant allele seemed to be associated with a decreased risk either in the dominant model [pooled OR = 0.944, 95% confidence interval (95% CI) 0.897-0.993, fixed-effects] or in the co-dominant model (AG vs. GG) (OR = 0.944, 95% CI 0.895-0.997, fixed-effects). rs1256049 was not associated with breast cancer risk in any model. Five studies had investigated the effect of haplotypes in the ESR2 gene on breast cancer risk, and four of them had positive outcomes. In summary, the present systematic review suggests that SNP rs4986938 as well as haplotypes in the ESR2 gene might be associated with breast cancer. The need for additional studies examining these issues seems of vital importance.

  4. 17beta-estradiol at physiological concentrations augments Ca(2+) -activated K+ currents via estrogen receptor beta in the gonadotropin-releasing hormone neuronal cell line GT1-7.

    PubMed

    Nishimura, Ichiro; Ui-Tei, Kumiko; Saigo, Kaoru; Ishii, Hirotaka; Sakuma, Yasuo; Kato, Masakatsu

    2008-02-01

    Estrogens play essential roles in the neuroendocrine control of reproduction. In the present study, we focused on the effects of 17beta-estradiol (E2) on the K(+) currents that regulate neuronal cell excitability and carried out perforated patch-clamp experiments with the GnRH-secreting neuronal cell line GT1-7. We revealed that a 3-d incubation with E2 at physiological concentrations (100 pm to 1 nm) augmented Ca(2+)-activated K(+) [K(Ca)] currents without influencing Ca(2+)-insensitive voltage-gated K(+) currents in GT1-7 cells. Acute application of E2 (1 nm) had no effect on the either type of K(+) current. The augmentation was completely blocked by an estrogen receptor (ER) antagonist, ICI-182,780. An ERbeta-selective agonist, 2,3-bis(4-hydroxyphenyl)-propionitrile, augmented the K(Ca) currents, although an ERalpha-selective agonist, 4,4',4''-[4-propyl-(1H)-pyrazole-1,3,5-triyl]tris-phenol, had no effect. Knockdown of ERbeta by means of RNA interference blocked the effect of E2 on the K(Ca) currents. Furthermore, semiquantitative RT-PCR analysis revealed that the levels of BK channel subunit mRNAs for alpha and beta4 were significantly increased by incubating cells with 300 pm E2 for 3 d. In conclusion, E2 at physiological concentrations augments K(Ca) currents through ERbeta in the GT1-7 GnRH neuronal cell line and increases the expression of the BK channel subunit mRNAs, alpha and beta4.

  5. Estrogen receptor alpha, fos-related antigen-2, and c-Jun coordinately regulate human UDP glucuronosyltransferase 2B15 and 2B17 expression in response to 17beta-estradiol in MCF-7 cells.

    PubMed

    Hu, Dong Gui; Mackenzie, Peter I

    2009-08-01

    UDP-glucuronosyltransferase 2B15 and 2B17 expression is up-regulated by 17beta-estradiol in MCF-7 breast cancer cells, as assessed by quantitative real-time polymerase chain reaction. Using 5'-deletion mapping and site-directed mutagenesis, we demonstrate that 17beta-estradiol activation of UGT2B15 gene transcription is mediated by a 282-base pair fragment positioned -454 to -172 nucleotides from the translation start site. This region contains two putative activator protein-1 (AP-1) elements, one imperfect estrogen response element (ERE), and two consensus ERE half-sites. We propose that these five sites act as an estrogen response unit (ERU), because mutation in any site reduces activation of the UGT2B15 promoter by 17beta-estradiol. Despite the presence of two AP-1 elements, the UGT2B15 promoter is not responsive to the AP-1 activator phorbol 12-myristate 13-acetate. Although electrophoretic mobility shift assays (EMSA) indicate that the AP-1 proteins c-Jun and Fos-related antigen 2 (Fra-2) bound to the distal AP-1 site, binding of Jun or Fos family members to the proximal AP-1 site was not detected by EMSA. Chromatin immunoprecipitation assays showed a 17beta-estradiol-induced recruitment of estrogen receptor (ER) alpha, c-Jun, and Fra-2 to the 282-bp ERU. The involvement of these three transcription factors in the stimulation of UGT2B15 gene expression by 17beta-estradiol was confirmed by siRNA silencing experiments. Mutagenesis and siRNA experiments indicate that UGT2B17 expression is also regulated by 17beta-estradiol via the ERU, which is fully conserved in both promoters. Because UGT2B15 and UGT2B17 inactivate steroid hormones by glucuronidation, the regulation of their genes by 17beta-estradiol may maintain steroid hormone homeostasis and prevent excessive estrogen signaling activity.

  6. [Estrogen receptor alpha in obesity and diabetes].

    PubMed

    Cahua-Pablo, José Ángel; Flores-Alfaro, Eugenia; Cruz, Miguel

    2016-01-01

    Estradiol (E2) is an important hormone in reproductive physiology, cardiovascular, skeletal and in the central nervous system (CNS). In human and rodents, E2 and its receptors are involved in the control of energy and glucose metabolism in health and metabolic diseases. The estrogen receptor (ER) belongs to the superfamily of nuclear receptors (NR), which are transcription factors that regulate gene expression. Three ER, ER-alpha, ER-beta and the G protein-coupled ER (GPER; also called GPR30) in tissues are involved in glucose and lipid homeostasis. Also, it may have important implications for risk factors associated with metabolic syndrome (MS), insulin resistance (IR), obesity and type 2 diabetes (T2D).

  7. Expression of Estrogen Receptor Beta Predicts Oncologic Outcome of pT3 Upper Urinary Tract Urothelial Carcinoma Better Than Aggressive Pathological Features

    PubMed Central

    Luo, Hao Lun; Sung, Ming Tse; Tsai, Eing Mei; Lin, Chang Shen; Lee, Nai Lun; Chung, Yueh-Hua; Chiang, Po Hui

    2016-01-01

    Upper urinary tract urothelial carcinoma (UT-UC) is rare and treatment options or prognostic markers are limited. There is increasing evidence indicating that urothelial carcinoma may be an endocrine-related cancer. The aim of this study was to analyze the prognostic effect of estrogen receptor beta (ERβ) on the outcome of UT-UC. From 2005 to 2012, this study included 105 patients with pT3 UT-UC. Perioperative factors, pathological features, and ERβ immunostaining were reviewed and prognostic effects were examined by multivariate analysis. This study divided patients into either the ERβ-high (n = 52) or ERβ-low (n = 53) group and analyzed their oncologic outcomes. All pathological features except infiltrating tumor architecture (significantly higher incidence in ERβ-low group, p = 0.004) are symmetric in both groups. Low ERβ expression was significantly correlated with local recurrence and distant metastasis in univariate analysis (p = 0.035 and 0.004, respectively) and multivariate analysis (p = 0.05 and 0.008, respectively). Cell line study also proved that knock down of ERβ cause less UTUC proliferation and migration. In addition, ERβ agonist also enhanced the cytotoxic and migration inhibition effect of cisplatin and ERβ antagonist cause the UTUC cell more resistant to cisplatin. This result may help identify patients in need of adjuvant therapy or develop potential targeted therapy. PMID:27052470

  8. Targeting Epigenetics Therapy for Estrogen Receptor-Negative Breast Cancers

    DTIC Science & Technology

    2014-10-01

    AWARD NUMBER: W81XWH-13-1-0400 TITLE: Targeting Epigenetics Therapy for Estrogen Receptor...2014 4. TITLE AND SUBTITLE Targeting Epigenetics Therapy for Estrogen Receptor-Negative Breast Cancers 5a. CONTRACT NUMBER 5b...estrogen- receptor positive breast cancer, estrogen receptor negative breast cancer, epigenetics , nuclear hormone receptor, estrogen Overall

  9. Seasonal expression of androgen receptor, aromatase, and estrogen receptor alpha and beta in the testis of the wild ground squirrel (Citellus dauricus Brandt).

    PubMed

    Li, Q; Zhang, F; Zhang, S; Sheng, X; Han, X; Weng, Q; Yuan, Z

    2015-02-17

    The aim of this study was to investigate the seasonal expression of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) mRNA and protein by real-time PCR and immunohistochemistry in the wild ground squirrel (WGS) testes. Histologically, all types of spermatogenic cells including mature spermatozoa were identified in the breeding season (April), while spermatogonia and primary spermatocytes were observed in the nonbreeding season (June), and spermatogonia, primary spermatocytes and secondary spermatocytes were found in pre-hibernation (September). AR was present in Leydig cells, peritubular myoid cells and Sertoli cells in the breeding season and pre-hibernation with more intense staining in the breeding season, whereas AR was only found in Leydig cells in the nonbreeding season; P450arom was expressed in Leydig cells, Sertoli cells and germ cells during the breeding season, whereas P450arom was found in Leydig cells and Sertoli cells during pre-hibernation, but P450arom was not present in the nonbreeding season; stronger immunohistochemical signal for ERα was present in Sertoli cells and Leydig cells during the breeding season; ERβ was only expressed in Leydig cells of the breeding season. Consistent with the immunohistochemical results, the mean mRNA level of AR, P450arom, ERα and ERβ were higher in the testes of the breeding season when compared to pre-hibernation and the nonbreeding season. These results suggested that the seasonal changes in spermatogenesis and testicular recrudescence and regression process in WGSs might be correlated with expression levels of AR, P450arom and ERs, and that estrogen and androgen may play an important autocrine/paracrine role to regulate seasonal testicular function.

  10. In vivo imaging of activated estrogen receptors in utero by estrogens and bisphenol A.

    PubMed

    Lemmen, Josephine G; Arends, Roel J; van der Saag, Paul T; van der Burg, Bart

    2004-11-01

    Environmental estrogens are of particular concern when exposure occurs during embryonic development. Although there are good models to study estrogenic activity of chemicals in adult animals, developmental exposure is much more difficult to test. The weak estrogenic activity of the environmental estrogen bisphenol A (BPA) in embryos is controversial. We have recently generated transgenic mice that carry a reporter construct with estrogen-responsive elements coupled to luciferase. We show that, using this in vivo model in combination with the IVIS imaging system, activation of estrogen receptors (ERs) by maternally applied BPA and other estrogens can be detected in living embryos in utero. Eight hours after exposure to 1 mg/kg BPA, ER transactivation could be significantly induced in the embryos. This was more potent than would be estimated from in vitro assays, although its intrinsic activity is still lower than that of diethylstilbestrol and 17beta-estradiol dipropionate. On the basis of these results, we conclude that the estrogenic potency of BPA estimated using in vitro assays might underestimate its estrogenic potential in embryos.

  11. Estrogen modulates alpha(1)/beta-adrenoceptor- induced signaling and melatonin production in female rat pinealocytes.

    PubMed

    Hernández-Díaz, F J; Sánchez, J J; Abreu, P; López-Coviella, I; Tabares, L; Prieto, L; Alonso, R

    2001-02-01

    Nocturnal rise in pineal melatonin output is due to the night-induced acceleration of noradrenergic transmission and alpha(1)- and beta-adrenoceptor activation. In addition, in female animals, cyclic oscillations in circulating levels of sex steroid hormones are accompanied by changes in the rate of pineal melatonin secretion. To investigate whether estrogen directly affects pineal adrenoceptor responsiveness, pinealocytes from 21-day-old ovariectomized rats were exposed to physiological concentrations of 17beta-estradiol (17beta-E(2)) and treated with noradrenergic agonists. Direct exposure to 17beta-E(2) reduced alpha(1)/beta-adrenoceptor-induced stimulation of melatonin synthesis and release. This effect was mediated by an estrogen-dependent inhibition of both beta-adrenoceptor-induced accumulation of cAMP and alpha(1)-adrenoceptor-induced phosphoinositide hydrolysis. Furthermore, estrogen reduced transient Ca(2+) signals elicited in single pinealocytes by alpha(1)-adrenoceptor activation or by potassium-induced depolarization. In the case of beta-adrenoceptor responsiveness, neither forskolin- nor cholera toxin-induced accumulation of cAMP were affected by previous exposure to 17beta-E(2). This indicates that estrogen effects must be exerted upstream from adenylylcyclase activation, and independent of modifications in G protein expression, therefore suggesting changes in either adrenoceptor expression or receptor-effector coupling mechanisms. Since estrogen effects upon adrenoceptor responsiveness in pineal cells was not mimicked by 17beta-E(2) coupled to bovine serum albumin and showed a latency of 48 h, this effect could be compatible with a genomic action mechanism. This is also consistent with the presence of two estrogen receptor proteins, alpha- and beta-subtypes, in female rat pinealocytes under the present experimental conditions.

  12. The effects of estrogen, its antagonist ICI 182, 780, and interferon-tau on the expression of estrogen receptors and integrin alphaV beta 3 on cycle day 16 in bovine endometrium

    PubMed Central

    Kimmins, Sarah; Russell, Gerald L; Lim, Hai Choo; Hall, Brian K; MacLaren, Leslie A

    2003-01-01

    We have shown previously that downregulation of intercaruncular stromal integrin αvβ3 in bovine endometrium on day 16 of the estrous cycle coincided with the antibody recognition of estrogen receptors (ER) in the luminal epithelium. In pregnancy, these changes were not observed. Our hypothesis was that on day 16 of the estrous cycle, estrogen from the dominant follicle causes a reduction in integrin αvβ3 and affects ERα in the luminal epithelium. The pregnancy recognition protein, interferon-τ (IFN-τ), may prevent downregulation of integrin αvβ3 and suppress ERα expression in the luminal epithelium. On days 14 to 16, heifers received uterine infusions of the anti-estrogen ICI 182, 780, estradiol 17β, IFN-τ or the saline control. On day 16, reproductive tracts were collected for analysis of integrin αvβ3 and ERα. Estrogen receptor α immunoreactivity was largely restricted to the luminal epithelium in control animals. Using anti-ERα recognizing the amino terminus, estrogen-treated animals showed reactivity in the stroma, shallow and deep glands and myometrium as is typical of estrus, whereas ICI 182, 870 treated heifers showed little or no reactivity. In contrast, carboxyl terminus-directed antibodies showed a widespread distribution of ERα with reactivity detected in the uterine epithelium, stroma and myometrium of both estrogen and ICI 182, 780 treated animals. Heifers treated with IFN-τ had low ERα reactivity overall. Control and IFN-τ treated heifers had lower intercaruncular stromal expression of integrin αvβ3 in comparison to estrogen and ICI 182, 780 treatments. Overall, the results suggest that on day 16 of the estrous cycle, estrogen effects on integrin αvβ3 are indirect and do not directly involve ERα in the luminal epithelium. During pregnancy, interferon-tau may block ERα in the luminal epithelium but likely does not rescue integrin αvβ3 expression. PMID:12756058

  13. Hepatic estrogen receptor and plasma 17{beta}-estradiol concentrations as biomarkers of 2,3,7,8-TCDD exposure in avian hatchlings

    SciTech Connect

    Janz, D.M.; Bellward, G.D.

    1995-12-31

    The authors have been investigating the sensitivity of various toxicologically relevant endpoints as environmental biomarkers in avian hatchlings exposed in ovo to 2,3,7,8-TCDD. Potential biomarkers included various endocrine endpoints such as plasma 17{beta}-estradiol (E{sub 2}), hepatic estrogen receptor (ER) affinities and concentrations, and plasma thyroid hormones, which were compared to hepatic ethoxyresorufin O-deethylase (EROD) induction. The animal models used were domestic chickens and pigeons, and great blue herons. An experiment conducted in pigeon hatchlings compared ``early`` (embryonic day 4; E4) vs. ``late`` (E14) in ovo exposure to 1 {micro}g/kg and 3 {micro}g/kg of TCDD, respectively. Birds were sacrificed on day of hatch (H) and day 7 after hatch (D7). In the late exposure experiment, plasma E{sub 2} concentrations were reduced at H and elevated at D7 in the TCDD-exposed birds (p < 0.05). Hepatic ER concentrations were elevated at H (p < 0.01). Although EROD was half-maximally induced at H and D7 in the early exposure experiment in pigeons, there was no effect of TCDD treatment on E, or ER levels. The nominal TCDD concentration in these pigeons (1 {micro}g/kg egg) was within the range observed in wild piscivorous bird eggs collected from aquatic systems contaminated with TCDD and related chemicals (approx. 0.5--2 ng TEQ/g egg). In herons exposed to 2 {micro}g/kg of TCDD at the midpoint of incubation, hepatic ER affinities (Kd) and concentrations (Bmax) were elevated in treated birds at H (p < 0.05); however there was no effect on plasma E, levels. Liver [{sup 3}H]-TCDD concentrations were 11.3 {+-} 0.8 ng/g at H, and 0.8 {+-} 0.1 ng/g at D7, representing 9.9% and 4.9% of the nominal TCDD dose, respectively.

  14. Association of increased estrogen receptor beta2 expression with parity-induced alterations in the rat mammary gland.

    PubMed

    Kass, Laura; Durando, Milena; Ramos, Jorge G; Varayoud, Jorgelina; Powell, Charles E; Luque, Enrique H; Muñoz-de-Toro, Mónica

    2004-06-01

    In this study, we investigated the cellular and molecular events involved in parity-related alterations in mammary gland (MG) proliferation and differentiation. Rat MGs were removed on day 9 of either first (nulliparous), second (primiparous) or third (multiparous) pregnancy. Expression of steroid hormone receptors along with cellular biomarkers of proliferation and differentiation were quantified in all MG tissue compartments by immunohistochemistry. Wnt-4 (a Wingless-like morphogenic gene involved in MG development), ERbeta and ERbeta2 mRNA were evaluated by RT-PCR analysis. Serum levels of mammotrophic hormones were measured. In comparison to nulliparous and primiparous rats, multiparous animals exhibited decreased luminal cell proliferation and PR levels, whereas alpha-lactalbumin, ERalpha, ERbeta and ERbeta2 expression were increased. In myoepithelial cells, while parity induced a decrease in proliferative activity, subsequent pregnancies and lactations lead to an increased state of differentiation. Our results showed that at least two periods of pregnancy and lactation were necessary to modify the studied parameters. The lower proliferative activity and higher differentiation state of the multiparous MG are associated with both a decreased PR expression and increased ERalpha and ERbeta expression. Since ERbeta and/or ERbeta2 isoform expression was related to parity history, results suggest that the decreased proliferative activity and PR expression observed in the MG of multiparous animals may be associated with overexpression of ERbeta and/or the ERbeta2 isoform, thereby antagonizing the proliferative effects associated with ERalpha.

  15. Estrogen receptor polymorphisms: significance to human physiology, disease and therapy.

    PubMed

    Figtree, Gemma A; Noonan, Jonathon E; Bhindi, Ravinay; Collins, Peter

    2009-01-01

    Other than its well-recognized effects on reproductive physiology, estrogen has important actions in a wide variety of other body systems with important examples including bone, blood vessels and the heart. These effects are seen in both females and males. Investigators have hypothesized those genetic variants in the genes coding for estrogen signaling proteins may cause variable sensitivity to the hormone and influence an individual's estrogen-sensitive phenotypes. The most obvious candidate genes are the estrogen receptors alpha and (ERalpha and beta). However, the regulation of these genes is complex and not well understood. Furthermore, their coding exons, and regulatory sequences are dispersed across large segments of the genome. A number of common polymorphisms have been identified in both ERalpha and ERbeta, with variable degrees of evidence of their direct biological significance and their association with human disease. The identification of genetic variations associated with altered estrogen response is of potential public health importance. Insights may be gained into the pathogenesis of estrogen sensitive diseases such as osteoporosis, breast cancer and cardiovascular disease contributing to the development and application of newer therapies for these disorders. Furthermore, genetic variants that alter sensitivity to estrogen may affect both therapeutic and harmful responses to exogenous estrogen administered in the form of the oral contraceptive pill or hormone replacement therapy. This clinical significance has led to the publication of a number of patents which will be reviewed.

  16. Targeted Radiotherapy of Estrogen Receptor Positive Tumors

    SciTech Connect

    Raghavan Rajagopalan

    2006-08-31

    The overall objectives of the proposal were to develop estrogen receptor (ER) binding small molecule radiopharmaceuticals for targeted radiotherapy of ER positive (ER+) tumors. In particular, this proposal focused on embedding a {sup 186,188}Re or a {sup 32}P radionuclide into an estrogen steroidal framework by isosteric substitution such that the resulting structure is topologically similar to the estrogen (estrogen mimic). The estrogen mimic molecules expected to bind to the ER and exhibit biodistribution akin to that of native estrogen due to structural mimicry. It is anticipated that the {sup 186,188}Re- or a {sup 32}P-containing estrogen mimics will be useful for targeted molecular radiotherapy of ER+ tumors. It is well established that the in vivo target tissue uptake of estrogen like steroidal molecules is related to the binding of the steroids to sex hormone binding globulin (SHBG). SHBG is important in the uptake of estrogens and testosterone in target tissues by SHBG receptors on the cell surface. However, hitherto the design of estrogen like small molecule radiopharmaceuticals was focused on optimizing ER binding characteristics without emphasis on SHBG binding properties. Consequently, even the molecules with good ER affinity in vitro, performed poorly in biodistribution studies. Based on molecular modeling studies the proposal focused on developing estrogen mimics 1-3 which were topologically similar to native estrogens, and form hydrogen bonds in ER and SHBG in the same manner as those of native estrogens. To this end the technical objectives of the proposal focused on synthesizing the rhenium-estrone and estradiol mimics 1 and 2 respectively, and phosphorous estradiol mimic 3 and to assess their stability and in vitro binding characteristics to ER and SHBG.

  17. Assessment of estrogen receptor--histone interactions.

    PubMed Central

    Kallos, J; Fasy, T M; Hollander, V P

    1981-01-01

    Several different in vitro binding assays show that the estrogen receptor from rabbit uterus interacts selectively with purified histones from calf thymus. The estrogen receptor binds strongly to histones H2B and H2A, moderately to histones H3 and H4, and poorly to histone H1. In the presence of histones H2B or H2A, the position at which the estrogen receptor focuses in an isoelectric gradient is shifted to a more basic zone. Kinetic experiments show that, if histone H2B is bound to a DNA, the estrogen receptor dissociates more slowly from that DNA. The portion of the estrogen receptor molecule required for binding to histone H2B is relatively stable to tryptic digestion; in contrast, the portion of the receptor molecule responsible for DNA binding is promptly lost during limited tryptic digestion. These in vitro findings suggest that the mechanism by which the estrogen receptor selectively alters gene expression may involve specific contacts with histone molecules. PMID:6942408

  18. Proestrous compared to diestrous wildtype, but not estrogen receptor beta knockout, mice have better performance in the spontaneous alternation and object recognition tasks and reduced anxiety-like behavior in the elevated plus and mirror maze.

    PubMed

    Walf, Alicia A; Koonce, Carolyn; Manley, Kevin; Frye, Cheryl A

    2009-01-23

    17beta-Estradiol (E(2)) may influence cognitive and/or affective behavior in part via the beta isoform of the estrogen receptor (ERbeta). Endocrine status and behavior in cognitive (object recognition, T-maze), anxiety (open field, elevated plus maze, mirror maze, emergence), and motor/coordination (rotarod, activity chamber) tasks of proestrous and diestrous wildtype (WT) and ERbeta knockout (betaERKO) mice was examined. Proestrous (WT or betaERKO), versus diestrous, mice had higher E(2) and progestin levels in plasma, hippocampus, and cortex. The only effect of genotype on hormone levels was for corticosterone, such that betaERKO mice had higher concentrations of corticosterone than did WT mice. Proestrous WT, but not betaERKO, mice had improved performance in the object recognition (greater percentage of time with novel object) and T-maze tasks (greater percentage of spontaneous alternations) and less anxiety-like behavior in the plus maze (increased duration on open arms) and mirror chamber task (increased duration in mirror) than did diestrous mice. This pattern was not seen in the rotarod, open field, or activity monitor, suggesting effects may be specific to affective and cognitive behavior, rather than motor behavior/coordination. Thus, enhanced performance in cognitive tasks and anti-anxiety-like behavior of proestrous mice may require actions of ERbeta in the hippocampus and/or cortex.

  19. Function of Estrogen Receptor Tryosine Phosphorylation

    DTIC Science & Technology

    1998-07-01

    6219 TITLE: Function of Estrogen Receptor Tryosine Phosphorylation PRINCIPAL INVESTIGATOR: Matthew R. Yudt CONTRACTING ORGANIZATION: University of...Estrogen Receptor Tryosine Phosphorylation ~DAMD17-96-1-6219 6. AUTHOR(S) Matthew R. Yudt 7. PERFORMING ORGANIZATION NAME11S) AND AODRESS(ES...this model, tyrosine 537 (Y537) phosphorylation of one monomer interacts with another tyrosine phosphorylated monomer to constitute an hER dimer

  20. [Estrogen receptors and the mammary gland].

    PubMed

    Barrón, A; Bermejo, L; Castro, I

    1997-01-01

    For several decades it has been known that steroid hormones, estrogen and progesterone, regulate some genes involved in the growth, proliferation and differentiation of the mammary-gland in animals and humans. In the last years, the presence or absence of the nuclear estrogen receptor has been used by clinicians as a marker for tumor malignancy, as a prognostic index or as an important parameter for hormonal therapy with anti-estrogenic compounds of some hormone-dependent breast cancers. This review shows some advances in the knowledge of the structure, function, molecular mechanisms of estrogenic activity, and interaction with proteins like protooncogenes and growth factors. Also, we refer to the role of the estrogen receptor in the physiophatology of breast cancer.

  1. Function of Estrogen Receptor Tryosine Phosphorylation

    DTIC Science & Technology

    1997-07-01

    localization of the receptors, ligand binding, DNA binding, transcriptional activation, and receptor turnover ( LeGoff et al. 1994; Lahooti et al. 1994...1040-1049 (1995). LeGoff P., M.M. Montano, D.J. Schodin, and B. Katzenellenbogen. Phosphorylation of the Human Estrogen Receptor. J. Biol. Chem

  2. Influence of Estradiol-17beta on Progesterone and Estrogen Receptor mRNA Expression in Porcine Follicular Granulosa Cells during Short-Term, In Vitro Real-Time Cell Proliferation

    PubMed Central

    Ciesiółka, Sylwia; Budna, Joanna; Jopek, Karol; Bryja, Artur; Kranc, Wiesława; Chachuła, Adrian; Borys, Sylwia; Dyszkiewicz Konwińska, Marta; Ziółkowska, Agnieszka; Antosik, Paweł; Bukowska, Dorota; Brüssow, Klaus P.; Bruska, Małgorzata; Nowicki, Michał

    2016-01-01

    Progesterone (P4) and estradiol (E2) play a significant role in mammalian reproduction. Our study demonstrated that separated porcine cumulus cells (CCs) and/or granulosa cells (GCs) might proliferate in vitro during short-term, real-time primary culture. The GCs were analyzed according to gene expression of the progesterone receptor (nuclear form) (pgr), progesterone receptor membrane component 1 (pgrmc1), and estrogen-related receptor beta 3 (esrrb3) in relation to two housekeeping genes: actb and pbgd. GCs were cultivated in medium with the E2. Both pgr/actb and pgr/pbgd revealed higher expression between 24 and 168 h of IVC of prolonged E2 treatment and at 48 h of IVC after acute E2 administration. The pgrmc1/actb and pgrmc1/pbgd displayed increased expression after prolonged E2 treatment between 24 and 120 h of IVC. The highest level of esrrb3/actb at 120 and 144 h, as well as esrrb3/pbgd at 120 h, in untreated controls as compared to the hormone-stimulated group, was observed. We suggest that E2 significantly influences the upregulation of pgr, pgrmc1, and esrrb3 expression in porcine GCs during real-time cell proliferation. Since esrrb3 expression is stimulated by E2 in both an acute and prolonged manner, estradiol may be recognized as a potential estrogen receptor agonist in GCs. PMID:28116305

  3. SCREENING CHEMICALS FOR ESTROGEN RECEPTOR ...

    EPA Pesticide Factsheets

    The U.S. Environmental Protection Agency (EPA) is considering the use high-throughput and computational methods for regulatory applications in the Endocrine Disruptor Screening Program (EDSP). To use these new tools for regulatory decision making, computational methods must be appropriately validated. Traditional validations of toxicity tests are time intensive, evaluate a relatively small number of chemicals, and are not well-suited to high-throughput methods. Here we describe a multi-step, performance-based validation establishing scientific confidence in new computational methods and demonstrating these tools are sufficiently robust to be used in a regulatory context. Results from 18 estrogen receptor (ER) ToxCast high-throughput screening assays, measuring different points along the signaling pathway with different assay technologies, were integrated into a computational model. The resulting ToxCast ER model scores range from 0 (no activity) to 1 (bioactivity of the native ligand, 17β-estradiol) and can discriminate ER bioactivity from assay-specific interference and cytotoxicity. ToxCast ER model performance was evaluated for 40 in vitro and 43 in vivo reference chemicals. ToxCast ER model results were also compared to EDSP Tier 1 screening assays in current regulatory practice for a diverse set of more than 100 chemicals. ToxCast ER model accuracy was 95% when compared to the large set of in vitro and in vivo reference chemicals. In addition, the T

  4. Molecular cloning and expression analysis of estrogen receptor betas (ERβ1 and ERβ2) during gonad development in the Korean rockfish, Sebastes schlegeli.

    PubMed

    Mu, W J; Wen, H S; Shi, D; Yang, Y P

    2013-07-01

    Estrogen receptors (ER) play a crucial role in mediation of estrogen activities. Here we report the isolation and expression analysis of ERβ1 and ERβ2 from ovary Korean rockfish (Sebastes schlegeli). were isolated using reverse transcription-polymerase chain reaction (PCR) and rapid amplification of cDNA ends procedures. The cDNA of this study, ERβ1 (588 amino acids) and ERβ2 (659 amino acids) were identified using reverse-transcriptase PCR (RT-PCR) and rapid amplification of cDNA ends procedures. Structural analysis showed both ERβs contain six typical nuclear receptor-characteristic domains. Phylogenetic analysis indicated that Korean rockfish ERβs were highly conserved among teleost. RT-PCR confirmed that the ERβs were widely distributed in both gonads and extra gonadal tissues. Further, we analyzed the expression patterns of male and female S. schlegeli during the reproductive cycle using quantitative real-time PCR (qRT-PCR). The results showed that the highest expression levels were observed in testis at immature sperm stage for both of KrERβ1 and KrERβ2. For female, the expressions of KrERβ1 and KrERβ2 were significantly higher in the ovary at the early-oocyte stage. Cloning these two ERβ subtypes in the Korean rockfish, together with the information on expression levels in adult fish has given us the foundation to investigate their possible role in brain-pituitary-gonad neuroendocrine axis in future studies.

  5. Mechanisms of estradiol-induced insulin secretion by the G protein-coupled estrogen receptor GPR30/GPER in pancreatic beta-cells.

    PubMed

    Sharma, Geetanjali; Prossnitz, Eric R

    2011-08-01

    Sexual dimorphism and supplementation studies suggest an important role for estrogens in the amelioration of glucose intolerance and diabetes. Because little is known regarding the signaling mechanisms involved in estradiol-mediated insulin secretion, we investigated the role of the G protein-coupled receptor 30, now designated G protein-coupled estrogen receptor (GPER), in activating signal transduction cascades in β-cells, leading to secretion of insulin. GPER function in estradiol-induced signaling in the pancreatic β-cell line MIN6 was assessed using small interfering RNA and GPER-selective ligands (G-1 and G15) and in islets isolated from wild-type and GPER knockout mice. GPER is expressed in MIN6 cells, where estradiol and the GPER-selective agonist G-1 mediate calcium mobilization and activation of ERK and phosphatidylinositol 3-kinase. Both estradiol and G-1 induced insulin secretion under low- and high-glucose conditions, which was inhibited by pretreatment with GPER antagonist G15 as well as depletion of GPER by small interfering RNA. Insulin secretion in response to estradiol and G-1 was dependent on epidermal growth factor receptor and ERK activation and further modulated by phosphatidylinositol 3-kinase activity. In islets isolated from wild-type mice, the GPER antagonist G15 inhibited insulin secretion induced by estradiol and G-1, both of which failed to induce insulin secretion in islets obtained from GPER knockout mice. Our results indicate that GPER activation of the epidermal growth factor receptor and ERK in response to estradiol treatment plays a critical role in the secretion of insulin from β-cells. The results of this study suggest that the activation of downstream signaling pathways by the GPER-selective ligand G-1 could represent a novel therapeutic strategy in the treatment of diabetes.

  6. Computational estimation of rainbow trout estrogen receptor binding affinities for environmental estrogens

    SciTech Connect

    Shyu, Conrad; Cavileer, Timothy D.; Nagler, James J.; Ytreberg, F. Marty

    2011-02-01

    Environmental estrogens have been the subject of intense research due to their documented detrimental effects on the health of fish and wildlife and their potential to negatively impact humans. A complete understanding of how these compounds affect health is complicated because environmental estrogens are a structurally heterogeneous group of compounds. In this work, computational molecular dynamics simulations were utilized to predict the binding affinity of different compounds using rainbow trout (Oncorhynchus mykiss) estrogen receptors (ERs) as a model. Specifically, this study presents a comparison of the binding affinity of the natural ligand estradiol-17{beta} to the four rainbow trout ER isoforms with that of three known environmental estrogens 17{alpha}-ethinylestradiol, bisphenol A, and raloxifene. Two additional compounds, atrazine and testosterone, that are known to be very weak or non-binders to ERs were tested. The binding affinity of these compounds to the human ER{alpha} subtype is also included for comparison. The results of this study suggest that, when compared to estradiol-17{beta}, bisphenol A binds less strongly to all four receptors, 17{alpha}-ethinylestradiol binds more strongly, and raloxifene has a high affinity for the {alpha} subtype only. The results also show that atrazine and testosterone are weak or non-binders to the ERs. All of the results are in excellent qualitative agreement with the known in vivo estrogenicity of these compounds in the rainbow trout and other fishes. Computational estimation of binding affinities could be a valuable tool for predicting the impact of environmental estrogens in fish and other animals.

  7. Tamoxifen increases nuclear respiratory factor 1 transcription by activating estrogen receptor beta and AP-1 recruitment to adjacent promoter binding sites.

    PubMed

    Ivanova, Margarita M; Luken, Kristen H; Zimmer, Amber S; Lenzo, Felicia L; Smith, Ryan J; Arteel, Maia W; Kollenberg, Tara J; Mattingly, Kathleen A; Klinge, Carolyn M

    2011-04-01

    Little is known about endogenous estrogen receptor β (ERβ) gene targets in human breast cancer. We reported that estradiol (E(2)) induces nuclear respiratory factor-1 (NRF-1) transcription through ERα in MCF-7 breast cancer cells. Here we report that 4-hydroxytamoxifen (4-OHT), with an EC(50) of ~1.7 nM, increases NRF-1 expression by recruiting ERβ, cJun, cFos, CBP, and RNA polymerase II to and dismissing NCoR from the NRF1 promoter. Promoter deletion and transient transfection studies showed that the estrogen response element (ERE) is essential and that an adjacent AP-1 site contributes to maximal 4-OHT-induced NRF-1 transcription. siRNA knockdown of ERβ revealed that ERβ inhibits basal NRF-1 expression and is required for 4-OHT-induced NRF-1 transcription. An AP-1 inhibitor blocked 4-OHT-induced NRF-1 expression. The 4-OHT-induced increase in NRF-1 resulted in increased transcription of NRF-1 target CAPNS1 but not CYC1, CYC2, or TFAM despite increased NRF-1 coactivator PGC-1α protein. The absence of TFAM induction corresponds to a lack of Akt-dependent phosphorylation of NRF-1 with 4-OHT treatment. Overexpression of NRF-1 inhibited 4-OHT-induced apoptosis and siRNA knockdown of NRF-1 increased apoptosis, indicating an antiapoptotic role for NRF-1. Overall, NRF-1 expression and activity is regulated by 4-OHT via endogenous ERβ in MCF-7 cells.

  8. Estrogen increases renal oxytocin receptor gene expression.

    PubMed

    Ostrowski, N L; Young, W S; Lolait, S J

    1995-04-01

    Estrogens have been implicated in the sodium and fluid imbalances associated with the menstrual cycle and late pregnancy. An estrogen-dependent role for renal oxytocin receptors in fluid homeostasis is suggested by the present findings which demonstrate that estradiol benzoate treatment increases the expression of the oxytocin receptor messenger ribonucleic acid and 125I-OTA binding to oxytocin receptors in the renal cortex and medullary collecting ducts of ovariectomized female rats. Moreover, estradiol induced high levels of oxytocin receptor expression in outer stripe proximal tubules of ovariectomized female and adrenalectomized male rats. Proximal tubule induction was inhibited in a dose-dependent manner by the antiestrogen tamoxifen, but cortical expression of oxytocin receptors in macula densa cells was unaffected by tamoxifen. These data demonstrate cell-specific regulation of oxytocin receptor expression in macula densa and proximal tubule cells, and suggest a important role for these receptors in mediating estrogen-induced alterations in renal fluid dynamics by possibly affecting glomerular filtration and water and solute reabsorption during high estrogen states.

  9. Effect of environmental estrogens on IL-1beta promoter activity in a macrophage cell line.

    PubMed

    Ruh, M F; Bi, Y; Cox, L; Berk, D; Howlett, A C; Bellone, C J

    1998-10-01

    Environmental estrogens or estrogen disrupters have recently received a great deal of attention because of their potential health impact on reproductive tissues. Few, if any, studies have been made on the impact of these compounds on the immune system. We sought to determine the activities of various environmental estrogens on the modulation of the interleukin-1beta (IL-1beta) gene in a model monocytic cell line, hER + IL-1beta-CAT+. This cell line stably transfected with the human estrogen receptor, and an IL-1beta promoter construct fused to the CAT reporter gene allows us to monitor the effect of estrogenic compounds on IL-1beta promoter activity. 17beta-estradiol (E2) markedly enhanced lipopolysaccharide- (LPS) induced IL-1beta promoter-driven CAT activity in a dose-dependent manner. The mycotoxins alpha-zearalenol and zearalenone both exhibited full agonist activity, but at lower potencies, with EC50 values of 1.8 and 54 nM, respectively, compared with E2 at 0.5 nM. In addition, genistein was a very low-potency agonist, having an EC50 of 1.5 microM. Similar to the E2 response, the slope factors for alpha-zearalenol, zearalenone, and genistein were close to 3.0, suggesting positive cooperativity in the estrogenic response. The activity of the mycotoxins appeared to be mediated through the estrogen receptor, since both the antiestrogens H1285 and ICI 182,780 effectively inhibited their agonist activity in a dose-dependent manner. Representative environmental estrogenic compounds both from plant and industrial sources were also tested. Unlike the mycoestrogens, none of the compounds, with the exception of genistein, synergized with LPS to enhance IL-1beta promoter activity. When tested for antiestrogenic activity, the industrial compound 4-octylphenol was able to antagonize the response to E2; however, the response was three orders of magnitude less potent than H 1285. Naringenin, a plant flavonoid, showed little or no ability to antagonize the response to E2

  10. Estrogen receptor-beta mediates the protective effects of aromatase induction in the MMTV-Her-2/neu x aromatase double transgenic mice.

    PubMed

    Nair, Hareesh B; Perla, Rao P; Kirma, Nameer B; Krishnegowda, Naveen K; Ganapathy, Manonmani; Rajhans, Rajib; Nair, Sujit S; Saikumar, Pothana; Vadlamudi, Ratna K; Tekmal, Rajeshwar Rao

    2012-04-01

    Breast cancers amplified for the tyrosine kinase receptor Her-2/neu constitute ~30% of advanced breast cancer cases, and are characterized by hormone independence and aggressive growth, implicating this pathway in breast oncogenesis. The induction of Her-2/neu leads to tumor development in 60% of transgenic mice. We have previously examined the effects of estrogen in the MMTV-Her-2/neu background by generating the MMTV-Her-2/neu x aromatase double transgenic mouse strain. MMTV-Her-2/neu x aromatase mice developed fewer mammary tumors than the Her-2/neu parental strain. Our present data show the induction of several estrogen-related genes, including the tumor suppressors BRCA1 and p53, and a decrease in several angiogenic factors. The phosphorylated forms of MAPK p42/44 and AKT were lower in the MMTV-Her-2/neu x aromatase double transgenic mice compared to the MMTV-Her-2/neu parental strain; conversely, phospho-p38 levels were higher in the double transgenic strain. The ERβ-selective antagonist THC reversed these changes. The regulation of these factors by ERβ was confirmed in clones of MCF7 breast cancer cells overexpressing Her-2/neu in combination with ERβ, suggesting that ERβ may play a direct role in regulating MAPK and AKT pathways. In summary, the data suggest that ERβ may play a major role in decreasing tumorigenesis and that it may affect breast cancer cell proliferation and survival by altering MAPK and AKT activation as well as modulation of tumor suppressor and angiogenesis factors. Treatment with selective ERβ agonist may provide therapeutic advantages for the treatment and prevention of breast cancer.

  11. Bioassays for estrogenic activity: development and validation of estrogen receptor (ERalpha/ERbeta) and breast cancer proliferation bioassays to measure serum estrogenic activity in clinical studies.

    PubMed

    Li, J; Lee, L; Gong, Y; Shen, P; Wong, S P; Wise, Stephen D; Yong, E L

    2009-02-01

    Standard estrogenic prodrugs such as estradiol valerate (E2V) and increasingly popular phytoestrogen formulations are commonly prescribed to improve menopausal health. These drugs are metabolized to numerous bioactive compounds, known or unknown, which may exert combinatorial estrogenic effects in vivo. The aim of this study is to develop and validate estrogen receptor (ER) alpha/ERbeta reporter gene and MCF-7 breast cancer cell proliferation bioassays to quantify serum estrogenic activities in a clinical trial setting. We measured changes in serum estrogenicity following ingestion of E2V and compared this to mass spectrometric measurements of its bioactive metabolites, estrone and 17beta-stradiol. ERalpha bioactivity of the 192 serum samples correlated well (R = 79%) with 17beta-estradiol levels, and adding estrone improved R to 0.83 (likelihood ratio test, P < 0.0001), suggesting that the ERalpha assay reflects summated activity of compounds in serum. ERbeta correlated moderately (R = 0.52) with estrone and 17beta-estradiol, with an estrone/17beta-estradiol coefficient ratio that was twice that of ERalpha, indicating estrone was more active on a molar basis in the ERbeta assay. Unlike the ERalpha and ERbeta bioassays, MCF-7 cell proliferation was driven by 17beta-estradiol, and addition of estrone did not increase the predictive value of the model, suggesting that the driver or drivers for breast cancer cell proliferation were not the same as for ERalpha and ERbeta transactivation. In contrast, a decoction of the traditional Chinese medicinal herb Epimedium pubescens did not induce significant changes in estrogenic bioactivity over baseline. These data indicate that ERalpha/ERbeta reporter gene and MCF-7 breast cancer cell proliferation bioassays reflect different aspects of estrogenic activity and that these assays suggest that the Epimedium formulation tested is unlikely to exert significant estrogenic effects in humans.

  12. MEMBRANE ESTROGEN RECEPTOR REGULATION OF HYPOTHALAMIC FUNCTION

    PubMed Central

    Micevych, Paul E.; Kelly, Martin J.

    2012-01-01

    Over the decades, our understanding of estrogen receptor (ER) function has evolved. Today we are confronted by at least two nuclear ERs: ERα and ERβ; and a number of putative membrane ERs, including ERα, ERβ, ER-X, GPR30 and Gq-mER. These receptors all bind estrogens or at least estrogenic compounds and activate intracellular signaling pathways. In some cases, a well-defined pharmacology, and physiology has been discovered. In other cases, the identity or the function remains to be elucidated. This mini-review attempts to synthesize our understanding of 17β-estradiol membrane signaling within hypothalamic circuits involved in homeostatic functions focusing on reproduction and energy balance. PMID:22538318

  13. Function of Estrogen Receptor Tryosine Phosphorylation

    DTIC Science & Technology

    1999-07-01

    phosphotyrosyl peptide that blocks dimerization of the human estrogen receptor. Proceedings of the National Academy of Sciences of the United States of America... Vivat , V., Chambon, P., Moras, D., and Gronemeyer, H. (1996) Nat. Struct. Biol. 3, 87-94 8. Shiau, A. K., Barstad, D., Loria, P. M., Cheng, L

  14. Estrogen receptor expert system overview and examples

    EPA Science Inventory

    The estrogen receptor expert system (ERES) is a rule-based system developed to prioritize chemicals based upon their potential for binding to the ER. The ERES was initially developed to predict ER affinity of chemicals from two specific EPA chemical inventories, antimicrobial pe...

  15. Messenger RNA levels of estrogen receptors alpha and beta and progesterone receptors in the cyclic and inseminated/early pregnant sow uterus.

    PubMed

    Sukjumlong, S; Persson, E; Dalin, A-M; Janson, V; Sahlin, L

    2009-06-01

    The aim of the present study was to investigate differences in the expression of mRNAs for ERalpha, ERbeta and PR in the sow uterus at different stages of the estrous cycle as well as in inseminated sows at estrus and during early pregnancy by use of solution hybridization and in relation to plasma levels of estradiol and progesterone. Uterine samples were collected at different stages of the estrous cycle and after insemination/early pregnancy. In the endometrium, the expression of ERalpha mRNA and PR mRNA was similar for cyclic and early pregnant groups. Both were highest at early diestrus/70 h after ovulation and ERalpha mRNA was lowest at late diestrus/d 19 while PR mRNA was lowest at diestrus and late diestrus/d 11 and d 19. The expression of endometrial ERbeta was constantly low during the estrous cycle but higher expression was found in inseminated/early pregnant sows at estrus and 70 h after ovulation. In the myometrium, high expression of ERalpha mRNA and PR mRNA was observed at proestrus and estrus in cyclic sows and at estrus in newly inseminated sows. Higher expression of myometrial ERbeta mRNA was found in inseminated/early pregnant sows compared with cyclic sows, although significant only at estrus. In conclusion, the expression of mRNAs for ERalpha, ERbeta and PR in the sow uterus differed between endometrium and myometrium as well as with stages of the estrous cycle and early pregnancy. In addition to plasma steroid levels, the differences between cyclic and inseminated/early pregnant sows suggest that other factors, e.g. insemination and/or the presence of embryos, influence the expression of these steroid receptor mRNAs in the sow uterus.

  16. Expression of androgen receptor, estrogen receptors alpha and beta and aromatase in the fetal, perinatal, prepubertal and adult testes of the South American plains Vizcacha, Lagostomus maximus (Mammalia, Rodentia).

    PubMed

    González, Candela Rocío; Muscarsel Isla, María Laura; Leopardo, Noelia Paola; Willis, Miguel Alfredo; Dorfman, Verónica Berta; Vitullo, Alfredo Daniel

    2012-01-01

    Androgens and androgen receptor play a critical role in spermatogenesis and fertility in mammals, and estrogens and their receptors contribute to regulation of testicular function through initiation and maintenance of spermatogenesis and germ cell division and survival. However, results from different species are still far from establishing a clear understanding of these receptors in the different cell types from the testis. We analyzed the expression of androgen receptor, estrogen receptors α and β and aromatase protein by immunohistochemistry and real-time PCR, in relation to proliferation followed by the expression of proliferation cell nuclear antigen (PCNA) and germinal identity by VASA protein, in fetal, perinatal, prepubertal and adult testes of Lagostomus maximus, a rodent with sustained germ cell proliferation and an increasing number of OCT-4-expressing gonocytes in the developing ovary. AR expression was restricted to Leydig cells and peritubular cells before sexual maturity, at which point it also became expressed in Sertoli cells. ERα and ERβ were expressed in seminiferous tubules and the interstitium, respectively, in both fetal and prepubertal testes. In adult testes, both ERα and ERβ co-localized in Leydig and peritubular cells. The aromatase enzyme, which converts androgenic precursors into estrogens, was detectable in all developmental stages analyzed and was restricted to Leydig cells. PCNA remained high until sexual maturity. ERα nuclear detection in germ cells and AR in Leydig cells in PCNA-positive cells suggest the possibility of a stimulatory effect of estrogens on spermatogonia proliferation. This effect might explain the increase found in VASA-expressing cells in the adult testis.

  17. Comparison of Individual and Combined Effects of Four Endocrine Disruptors on Estrogen Receptor Beta Transcription in Cerebellar Cell Culture: The Modulatory Role of Estradiol and Triiodo-Thyronine

    PubMed Central

    Jocsak, Gergely; Kiss, David Sandor; Toth, Istvan; Goszleth, Greta; Bartha, Tibor; Frenyo, Laszlo V.; Horvath, Tamas L.; Zsarnovszky, Attila

    2016-01-01

    Background: Humans and animals are continuously exposed to a number of environmental substances that act as endocrine disruptors (EDs). While a growing body of evidence is available to prove their adverse health effects, very little is known about the consequences of simultaneous exposure to a combination of such chemicals; Methods: Here, we used an in vitro model to demonstrate how exposure to bisphenol A, zearalenone, arsenic, and 4-methylbenzylidene camphor, alone or in combination, affect estrogen receptor β (ERβ) mRNA expression in primary cerebellar cell cultures. Additionally, we also show the modulatory role of intrinsic biological factors, such as estradiol (E2), triiodo-thyronine (T3), and glial cells, as potential effect modulators; Results: Results show a wide diversity in ED effects on ERβ mRNA expression, and that the magnitude of these ED effects highly depends on the presence or absence of E2, T3, and glial cells; Conclusion: The observed potency of the EDs to influence ERβ mRNA expression, and the modulatory role of E2, T3, and the glia suggests that environmental ED effects may be masked as long as the hormonal milieu is physiological, but may tend to turn additive or superadditive in case of hormone deficiency. PMID:27338438

  18. Selectively targeting estrogen receptors for cancer treatment

    PubMed Central

    Shanle, Erin K.; Xu, Wei

    2010-01-01

    Estrogens regulate growth and development through the action of two distinct estrogen receptors (ERs), ERα and ERβ, which mediate proliferation and differentiation of cells. For decades, ERα mediated estrogen signaling has been therapeutically targeted to treat breast cancer, most notably with the selective estrogen receptor modulator (SERM) tamoxifen. Selectively targeting ERs occurs at two levels: tissue selectivity and receptor subtype selectivity. SERMs have been developed with emphasis on tissue selectivity to target ER signaling for breast cancer treatment. Additionally, new approaches to selectively target the action of ERα going beyond ligand-dependent activity are under current investigation. As evidence of the anti-proliferative role of ERβ accumulates, selectively targeting ERβ is an attractive approach for designing new cancer therapies with the emphasis shifted to designing ligands with subtype selectivity. This review will present the mechanistic and structural features of ERs that determine tissue and subtype selectivity with an emphasis on current approaches to selectively target ERα and ERβ for cancer treatment. PMID:20708050

  19. Autocrine role of estrogens in the augmentation of luteinizing hormone receptor formation in cultured rat granulosa cells.

    PubMed

    Kessel, B; Liu, Y X; Jia, X C; Hsueh, A J

    1985-06-01

    The effects of estrogens on gonadotropin-stimulated luteinizing hormone (LH) receptor formation were examined in primary cultures of rat granulosa cells. Granulosa cells were cultured for 3 days with increasing concentrations of follicle-stimulating hormone (FSH) in the presence or absence of native and synthetic estrogens. Follicle-stimulating hormone stimulated LH receptor formation in a dose-dependent fashion, and estrogens enhanced the FSH-stimulated LH receptor content by decreasing the apparent ED50 of FSH. At 6.25 ng/ml FSH, the enhancement in LH receptor was estrogen dose dependent, with an ED50 value of about 3 X 10(-9) M for 17 beta-estradiol. The increased LH receptor content seen in cells treated with FSH and estrogen was correlated with increased cAMP production by these cells in response to LH stimulation. Time course studies revealed enhancement of FSH-stimulated LH receptor induction at 48 and 72 h of culture. Granulosa cells were also cultured with FSH for 2 days to induce functional LH receptors, then further cultured for 3 days with LH in the presence or absence of estrogens. At 30 ng/ml LH, increasing concentrations of estrogens maintained LH receptor content in a dose-dependent fashion, with their relative estrogenic potencies in keeping with reported binding affinities to estrogen receptors. An autocrine role of estrogens on LH receptor formation was further tested in granulosa cells treated with FSH and an aromatase substrate (androstenedione) to increase estrogen biosynthesis. Cotreatment with semipurified estrogen antibodies partially blocked the FSH stimulation of LH receptors, whereas nonimmune serum was ineffective. Also, inclusion of diethylstilbestrol prevented the inhibitory effect of the estrogen antibodies. Thus, local estrogens in ovarian follicles may play an autocrine role in granulosa cells to enhance LH receptor formation and to increase granulosa cell responsiveness to the LH surge, with subsequent ovulation and adequate

  20. Cell Cycle Regulation of Estrogen and Androgen Receptor

    DTIC Science & Technology

    2002-07-01

    Estrogen and Androgen Receptor PRINCIPAL INVESTIGATOR: Elisabeth D. Martinez CONTRACTING ORGANIZATION: Georgetown University Medical Center...Cycle Regulation of Estrogen and Androgen DAMD17-99-1-9199 Receptor 6. AUTHOR(S) Elisabeth D. Martinez 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...with androgens. 14. SUBJECT TERMS 15. NUMBER OF PAGES breast cancer, cell cycle, androgen receptor, estrogen receptor, non- 66 steroidal activators, L

  1. Radiobrominated triphenylethylenes as estrogen receptor binding radiopharmaceuticals

    SciTech Connect

    Seevers, R.H.; Meese, R.C.; Friedman, A.M.; DeSombre, E.R.

    1985-05-01

    Estrogen receptor binding radiopharmaceuticals have potential for use in the diagnosis and treatment of cancers of the female reproductive system. Tamoxifen is an antiestrogen derived from the triphenylethylene skeleton which is used in the treatment of mammary carcinoma. Hydroxytamoxifen is a metabolite of tamoxifen which binds tightly to the estrogen receptor. Two triphenylethylene derivatives based on the structure of hydroxytamoxifen have been prepared: 1-bromo-1-phenyl-2- (2-dimethylamino)-4-ethoxyphenyl -2-(4-hydroxyphenyl) ethene (1) where the ethyl group of hydroxytamoxifen has been replaced by a bromine, and 1-bromo-1-phenyl-2,2-(4-hydroxyphenyl) ethene (2) with a similar substitution and also lacking the aminoethoxy side chain believed to confer antiestrogenicity. Both 1 and 2 bind strongly to the estrogen receptor. 2 has been labeled with the Auger electron emitting nuclide Br-80m in moderate yields in high specific activity using either N-bromosuccinimide or N-bromophthalimide and shows promise as a potential radiotherapy agent.

  2. Estrogen receptor beta growth-inhibitory effects are repressed through activation of MAPK and PI3K signalling in mammary epithelial and breast cancer cells.

    PubMed

    Cotrim, C Z; Fabris, V; Doria, M L; Lindberg, K; Gustafsson, J-Å; Amado, F; Lanari, C; Helguero, L A

    2013-05-09

    Two thirds of breast cancers express estrogen receptors (ER). ER alpha (ERα) mediates breast cancer cell proliferation, and expression of ERα is the standard choice to indicate adjuvant endocrine therapy. ERbeta (ERβ) inhibits growth in vitro; its effects in vivo have been incompletely investigated and its role in breast cancer and potential as alternative target in endocrine therapy needs further study. In this work, mammary epithelial (EpH4 and HC11) and breast cancer (MC4-L2) cells with endogenous ERα and ERβ expression and T47-D human breast cancer cells with recombinant ERβ (T47-DERβ) were used to explore effects exerted in vitro and in vivo by the ERβ agonists 2,3-bis (4-hydroxy-phenyl)-propionitrile (DPN) and 7-bromo-2-(4-hydroxyphenyl)-1,3-benzoxazol-5-ol (WAY). In vivo, ERβ agonists induced mammary gland hyperplasia and MC4-L2 tumour growth to a similar extent as the ERα agonist 4,4',4''-(4-propyl-(1H)-pyrazole-1,3,5-triyl) trisphenol (PPT) or 17β-estradiol (E2) and correlated with higher number of mitotic and lower number of apoptotic features. In vitro, in MC4-L2, EpH4 or HC11 cells incubated under basal conditions, ERβ agonists induced apoptosis measured as upregulation of p53 and apoptosis-inducible factor protein levels and increased caspase 3 activity, whereas PPT and E2 stimulated proliferation. However, when extracellular signal-regulated kinase 1 and 2 (ERK ½) were activated by co-incubation with basement membrane extract or epidermal growth factor, induction of apoptosis by ERβ agonists was repressed and DPN induced proliferation in a similar way as E2 or PPT. In a context of active ERK ½, phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/RAC-alpha serine/threonine-protein kinase (AKT) signalling was necessary to allow proliferation stimulated by ER agonists. Inhibition of MEK ½ with UO126 completely restored ERβ growth-inhibitory effects, whereas inhibition of PI3K by LY294002 inhibited ERβ-induced proliferation. These

  3. Stimulation of transactivation of the largemouth bass estrogen receptors alpha, beta-a, and beta-b by methoxychlor and its mono- and bis-demethylated metabolites in HepG2 cells

    PubMed Central

    Blum, Jason L.; James, Margaret O.; Stuchal, Leah D.; Denslow, Nancy D.

    2008-01-01

    The purpose of this study was to determine the mechanisms by which the pesticide, methoxychlor (MXC), acts as an environmental endocrine disruptor through interaction with the three largemouth bass (Micropterus salmoides) estrogen receptors (ERs) α, βa, and βb. MXC is a less-environmentally persistent analog of DDT that behaves as a weak estrogen. Using transient transfection assays in HepG2 cells, we have previously shown that each receptor is responsive to the endogenous ligand 17β-estradiol (E2) in a dose-dependent manner. The parent compound, MXC, showed dose-dependent stimulation of transcriptional activation through all three ERs. In addition to the parent molecule, each of the metabolites was also estrogenic with all three ERs. The order of potency for ERα and ERβb was HPTE > OH-MXC > MXC, while the opposite order was seen for ERβa. HepG2 cells did not substantially metabolize MXC to the active metabolites, thus the activity of MXC was not due to metabolism. When examining the effects of increasing concentrations of MXC at a fixed concentration of E2, all three ERs show increased activity compared to that with E2 alone, showing that the effects of MXC and E2 are additive. However, when this experiment was repeated with increasing concentrations of HPTE at a fixed concentration of E2, the activity of ERα was decreased, that of ERβb was increased, while that of ERβa was unaffected compared to E2 alone. These experiments suggest that HPTE functions as an E2 antagonist with Erα, an E2 agonist with ERβb and does not perturb E2 stimulation of ERβa. While it is clear the ERβ subtypes are the products of different genes (due to a gene duplication in teleosts) the differences in their responses to MXC and its metabolites indicate that their functions diverge, both in their in vivo molecular response to E2, as well as to their interaction with endocrine disrupting compounds found in the wild. PMID:17949972

  4. Cell Cycle Regulation of Estrogen and Androgen Receptor

    DTIC Science & Technology

    2001-07-01

    EC50 . "* It has been established that the estrogen receptor shows highest activity when the cells are treated by serum starvation and are mainly in GO...of Estrogen and Androgen Receptor PRINCIPAL INVESTIGATOR: Elisabeth D. Martinez CONTRACTING ORGANIZATION: Georgetown University Medical Center... Estrogen and Androgen Receptor DAMD 17-99-1- 9199 6. AUTHOR(S) Elisabeth D. Martinez 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING

  5. [Chronic administration of estrogen receptors antagonist reduces degree of hypoxia-induced pulmonary hypertension caused by chronic injections of estrogen in ovariectomised female Wistar rats].

    PubMed

    Kovaleva, Iu O; Artem'eva, M M; Medvedev, O S; Medvedeva, N A

    2013-01-01

    As we showed previously, administration of estradiol in different doses (5 and 15 mcg per day for 21 day) initiates the development of pulmonary arterial hypertension (PAH) in ovariectomised female Wistar rats. The aim of current study was to analyze the involvement of antagonist of estrogen receptors type a- and beta- ICI 182,780 (fulvestrant) in development of hypoxia-induced pulmonary arterial hypertension. Ovariectomised female rats were separated into 5 groups received subcutaneously for 1 month : 1. Estrogen 15 mcg per day. 2. Estrogen 60 mcg per day 3. Antagonist of estrogen receptors type alpha- and beta- fulvestrant 150 mcg per day. 4. Estrogen 15 mcg/d + fulvestrant 150 mcg/d. 5. Propylenglycol as a control group. PAH was induced by exposure to hypobaric hypoxia. Rats were housed in a hypobaric chamber at simulated altitude of 5000 m, 10 h a day, 2 wk (O2 concentration reduced to 10%). We suppose that the development of pulmonary hypertension in ovariectomised female Wistar rats caused by administration of estrogen (15 mcg and 60 mcg per day for 1 month) is mediated by estrogen receptors type alpha- and beta-.

  6. Drug targeting of estrogen receptor signaling in the cardiovascular system: preclinical and clinical studies.

    PubMed

    Sanz-González, Silvia M; Cano, Antonio; Valverde, M A; Hermenegildo, Carlos; Andrés, Vicente

    2004-04-01

    Atherosclerosis and associated coronary heart disease events have lower prevalence in women than in men, especially during young adult years. Although multiple lines of evidence suggest that estrogens contribute to this difference, the efficacy of hormone replacement therapy for the prevention of cardiovascular disease in postmenopausal women is controversial. The protective action of estrogen in the cardiovascular system appears to be mediated indirectly by an effect on serum lipoprotein and triglyceride profiles and on the expression of coagulant and fibrinolytic proteins, and by a direct effect on the vessel wall itself. Estrogen has both rapid effects involving alteration of membrane ionic permeability and activation of membrane-bound enzymes and increases in endothelial cell nitric oxide synthase activity, as well as longer-term effects on gene expression that are mediated, at least in part, by the ligand-activated transcription factors, estrogen receptor alpha and beta. Compounds with pure antiestrogenic activity and selective estrogen receptor modulators that regulate estrogen receptor function in a tissue-specific manner have been developed in an attempt to achieve the cardioprotective effects of estrogens while minimizing the undesirable risks associated with hormone replacement therapy (e.g., endometrial and breast cancer). In this review, we will discuss recent developments on the mechanisms of estrogen action in the cardiovascular system. The results of clinical trials testing the long-term efficacy of hormone replacement therapy for the treatment of cardiovascular disease will also be discussed.

  7. Synergistic activation of estrogen receptor with combinations of environmental chemicals

    SciTech Connect

    Arnold, S.F.; Klotz, D.M.; Collins, B.M.

    1996-06-07

    Certain chemicals in the environment are estrogenic. The low potencies of the compounds, when studied singly, suggest that they may have little effect on biological systems. The estrogenic potencies of combinations of such chemicals were screened in a simple yeast estrogen potencies of combination of such chemicals were screened in a simple yeast estrogen systems (YES) containing human estrogen receptor (hER). Combinations of two weak environmental estrogens, such as dieldrin, endosulfan, or toxaphene, were 100 times as potent in hER-mediated transactivation as any chemical alone. Hydroxylated polychlorinated biphenyls shown previously to synergistically alter sexual development in turtles also synergized in the YES. The synergistic interaction of chemical mixtures with the estrogen receptor may have profound environmental implications. These results may represent a previously uncharacterized level of regulation of estrogen-associated responses. 32 refs., 3 figs., 3 tabs.

  8. Identification of an estrogenic hormone receptor in Caenorhabditis elegans

    SciTech Connect

    Mimoto, Ai; Fujii, Madoka; Usami, Makoto; Shimamura, Maki; Hirabayashi, Naoko; Kaneko, Takako; Sasagawa, Noboru; Ishiura, Shoichi

    2007-12-28

    Changes in both behavior and gene expression occur in Caenorhabditis elegans following exposure to sex hormones such as estrogen and progesterone, and to bisphenol A (BPA), an estrogenic endocrine-disrupting compound. However, only one steroid hormone receptor has been identified. Of the 284 known nuclear hormone receptors (NHRs) in C. elegans, we selected nhr-14, nhr-69, and nhr-121 for analysis as potential estrogenic hormone receptors, because they share sequence similarity with the human estrogen receptor. First, the genes were cloned and expressed in Escherichia coli, and then the affinity of each protein for estrogen was determined using a surface plasmon resonance (SPR) biosensor. All three NHRs bound estrogen in a dose-dependent fashion. To evaluate the specificity of the binding, we performed a solution competition assay using an SPR biosensor. According to our results, only NHR-14 was able to interact with estrogen. Therefore, we next examined whether nhr-14 regulates estrogen signaling in vivo. To investigate whether these interactions actually control the response of C. elegans to hormones, we investigated the expression of vitellogenin, an estrogen responsive gene, in an nhr-14 mutant. Semi-quantitative RT-PCR showed that vitellogenin expression was significantly reduced in the mutant. This suggests that NHR-14 is a C. elegans estrogenic hormone receptor and that it controls gene expression in response to estrogen.

  9. Vascular estrogen receptors and endothelium-derived nitric oxide production in the mouse aorta. Gender difference and effect of estrogen receptor gene disruption.

    PubMed Central

    Rubanyi, G M; Freay, A D; Kauser, K; Sukovich, D; Burton, G; Lubahn, D B; Couse, J F; Curtis, S W; Korach, K S

    1997-01-01

    The present study was designed to test the hypothesis that estrogen receptors (ER) in the blood vessel wall play a role in the modulation of the release of endothelium-derived nitric oxide (EDNO). Both basal and stimulated release of EDNO were determined in aortic rings isolated from female and male wild-type and male homozygous estrogen receptor knock-out (ERKO) mice. 125I-17beta-estradiol binding in aortic tissue showed significantly more high affinity cytosolic- nuclear-binding sites in male compared with female wildtype mice. Estrogen receptor transcripts were present in the aorta of male wild-type mice, but they were absent in male ERKO animals. Basal release of EDNO (determined by endothelium-dependent contraction caused by NG-nitro-arginine) was significantly higher in aorta of wild-type male mice compared with wild-type female mice, and significantly lower in the aorta of male ERKO compared with male wild-type mice. Acetylcholine-induced endothelium-dependent relaxation was similar in all groups studied. No difference was observed in the activity of calcium-dependent nitric oxide synthase in homogenates of lungs and brain taken from male wild-type and ERKO mice. These studies show a significant association between the number of estrogen receptors and basal release of EDNO in the aorta of mice, and suggest that decreased vascular estrogen receptor number may represent a novel risk factor for cardiovascular diseases. PMID:9153286

  10. Steroid binding domain of porcine estrogen receptor

    SciTech Connect

    Koike, S.; Nii, A.; Sakai, M.; Muramatsu, M.

    1987-05-05

    For the purpose of characterizing the estrogen binding domain of porcine estrogen receptor (ER), the authors have made use of affinity labeling of partially purified ER with (/sup 3/H)tamoxifen aziridine. The labeling is very efficient and selective particularly after partial purification of ER. A 65,000-dalton (65-kDa) band was detected on the fluorogram of a sodium dodecyl sulfate-polyacrylamide gel, together with a 50-kDa band and a few more smaller bands. The 50-kDa protein appears to be a degradation product of the 65-kDa protein in view of the similar peptide map. ER was affinity labeled before or after controlled limited proteolysis with either trypsin, papain, or ..cap alpha..-chymotrypsin. The labeling patterns of limited digests indicate that a fragment of about 30 kDa is relatively resistant to proteases and has a full and specific binding activity to estrogen, whereas smaller fragments have lost much of the binding activity. This fragment is very hydrophobic and probably corresponds to the carboxy half of ER.

  11. Insights from the Study of Animals Lacking Functional Estrogen Receptor

    NASA Astrophysics Data System (ADS)

    Korach, Kenneth S.

    1994-12-01

    Estrogen hormones produce physiological actions within a variety of target sites in the body and during development by activating a specific receptor protein. Hormone responsiveness for the estrogen receptor protein was investigated at different stages of development with the use of gene knockout techniques because no natural genetic mutants have been described. A mutant mouse line without a functional estrogen receptor was created and is being used to assess estrogen responsiveness. Both sexes of these mutant animals are infertile and show a variety of phenotypic changes, some of which are associated with the gonads, mammary glands, reproductive tracts, and skeletal tissues.

  12. Estrogen Receptor Alpha G525L Knock-In-Mice

    DTIC Science & Technology

    2006-03-01

    Padilla-Banks E, Clark G, Newbold RR. Assessing estrogenic activity of phytochemicals using transcriptional activation and immature mouse...AD_________________ Award Number: W81XWH-04-1-0347 TITLE: Estrogen Receptor Alpha G525L...TITLE AND SUBTITLE Estrogen Receptor Alpha G525L Knock-In Mice 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-04-1-0347 5c. PROGRAM ELEMENT

  13. Estrogen inhibits RANKL-stimulated osteoclastic differentiation of human monocytes through estrogen and RANKL-regulated interaction of estrogen receptor-{alpha} with BCAR1 and Traf6

    SciTech Connect

    Robinson, Lisa J.; Yaroslavskiy, Beatrice B.; Griswold, Reed D.; Zadorozny, Eva V.; Guo, Lida; Tourkova, Irina L.; Blair, Harry C.

    2009-04-15

    The effects of estrogen on osteoclast survival and differentiation were studied using CD14-selected mononuclear osteoclast precursors from peripheral blood. Estradiol at {approx} 1 nM reduced RANKL-dependent osteoclast differentiation by 40-50%. Osteoclast differentiation was suppressed 14 days after addition of RANKL even when estradiol was withdrawn after 18 h. In CD14+ cells apoptosis was rare and was not augmented by RANKL or by 17-{beta}-estradiol. Estrogen receptor-{alpha} (ER{alpha}) expression was strongly down-regulated by RANKL, whether or not estradiol was present. Mature human osteoclasts thus cannot respond to estrogen via ER{alpha}. However, ER{alpha} was present in CD14+ osteoclast progenitors, and a scaffolding protein, BCAR1, which binds ER{alpha} in the presence of estrogen, was abundant. Immunoprecipitation showed rapid ({approx} 5 min) estrogen-dependent formation of ER{alpha}-BCAR1 complexes, which were increased by RANKL co-treatment. The RANKL-signaling intermediate Traf6, which regulates NF-{kappa}B activity, precipitated with this complex. Reduction of NF-{kappa}B nuclear localization occurred within 30 min of RANKL stimulation, and estradiol inhibited the phosphorylation of I{kappa}B in response to RANKL. Inhibition by estradiol was abolished by siRNA knockdown of BCAR1. We conclude that estrogen directly, but only partially, curtails human osteoclast formation. This effect requires BCAR1 and involves a non-genomic interaction with ER{alpha}.

  14. Involvement of Human Estrogen Related Receptor Alpha 1 (hERR 1) in Breast Cancer and Hormonally Insensitive Disease

    DTIC Science & Technology

    2000-08-01

    Coutts, A., and Watson , P. The pathophysiological role of estrogen receptor variants in human breast cancer, J Steroid Biochem Mol Biol. 65: 175-80, 1998...breast cancer, Clin Cancer Res. 6: 512-8, 2000. 37. Leygue, E., Dotzlaw, H., Watson , P. H., and Murphy, L. C. Altered estrogen receptor alpha and beta...amphiregulin and CRIPTO in human normal and malignant breast tissues, Int J Cancer. 65: 51-6, 1996. 124. Depowski, P. L., Brien, T. P., Sheehan, C. E

  15. Expression of Estrogen Receptor Alpha in Malignant Melanoma

    PubMed Central

    Rajabi, Parvin; Bagheri, Marzieh; Hani, Mohsen

    2017-01-01

    Background: Features of malignant melanoma (MM) vary in the different geographic regions of the world. This may be attributable to environmental, ethnic, and genetic factors. The aim of this study was to determine the expression of estrogen receptor alpha (ER-α) in MM in Isfahan, Iran. Materials and Methods: This study was planned as a descriptive, analytical, cross-sectional investigation. During this study, paraffin-embedded tissue blocks of patients with a histopathologic diagnosis of MM was studied for ER-α using immunohistochemistry (IHC). Results: In this study, 38 patients (female/male; 20/18) with a definite diagnosis of malignant cutaneous melanoma and mean age of 52.4 ± 11.2 years were investigated. Using envision IHC staining, there were not any cases with ER-α expression. Conclusion: In confirmation to the most previous studies, expression of ER-α was negative in MM. It is recommended to investigate the expression of estrogen receptor beta and other markers in MM. PMID:28299306

  16. Increased steroid receptor RNA activator protein (SRAP) accompanied by decreased estrogen receptor-beta (ER-β) levels during the malignant transformation of endometriosis associated ovarian clear cell carcinoma.

    PubMed

    Lin, Kaiqing; Zhan, Hong; Ma, Junyan; Xu, Kaihong; Wu, Ruijin; Zhou, Caiyun; Lin, Jun

    2014-06-01

    The modulating attributes of steroid receptor RNA activator protein (SRAP) on steroid receptors have been shown in some types of tumor cells. There is compelling evidence to suggest that this molecule may play a critical role in the development of the tumor. However, little has been reported on its expression in endometriosis associated ovarian clear cell carcinoma (EAOCCC). In order to investigate the role of SRAP and estrogen receptors (ERs) in EAOCCC, we have analyzed the distribution of these proteins in the malignant transformation tissues and endometrioma tissues by immunohistochemistry. Our results revealed that the positive ratio of ER-β expression was gradually reduced during the malignant transformation from endometriosis to atypical endometriosis to clear cell carcinoma. Conversely, during the process, a gradual increase in SRAP expression was observed. Furthermore, there is a negative relationship between the expressions of these two molecules. Overall an increase in SRAP and a reduction in ER-β expression might be associated with malignant transformation of EAOCCC.

  17. Estrogen induced {beta}-1,4-galactosyltransferase 1 expression regulates proliferation of human breast cancer MCF-7 cells

    SciTech Connect

    Choi, Hee-Jung; Chung, Tae-Wook; Kim, Cheorl-Ho; Jeong, Han-Sol; Joo, Myungsoo; Youn, BuHyun; Ha, Ki-Tae

    2012-10-05

    Highlights: Black-Right-Pointing-Pointer We examined the regulation and biological functions of B4GALT1 expression induced by estrogen. Black-Right-Pointing-Pointer Estrogen-induced B4GALT1 expression through the direct binding of ER-{alpha} to ERE in MCF-7 cells. Black-Right-Pointing-Pointer B4GALT1 expression activates the proliferation of MCF-7 cells via its receptor function. Black-Right-Pointing-Pointer Thus, we suggest B4GALT1 as a molecular target for inhibiting breast cancer proliferation. -- Abstract: Beta 1,4-galactosyltransferase 1 (B4GALT1) synthesizes galactose {beta}-1,4-N-acetylglucosamine (Gal{beta}1-4GlcNAc) groups on N-linked sugar chains of glycoproteins, which play important roles in many biological events, including the proliferation and migration of cancer cells. A previous microarray study reported that this gene is expressed by estrogen treatment in breast cancer. In this study, we examined the regulatory mechanisms and biological functions of estrogen-induced B4GALT1 expression. Our data showed that estrogen-induced expression of B4GALT1 is localized in intracellular compartments and in the plasma membrane. In addition, B4GALT1 has an enzyme activity involved in the production of the Gal{beta}1-4GlcNAc structure. The result from a promoter assay and chromatin immunoprecipitation revealed that 3 different estrogen response elements (EREs) in the B4GALT1 promoter are critical for responsiveness to estrogen. In addition, the estrogen antagonists ICI 182,780 and ER-{alpha}-ERE binding blocker TPBM inhibit the expression of estrogen-induced B4GALT1. However, the inhibition of signal molecules relating to the extra-nuclear pathway, including the G-protein coupled receptors, Ras, and mitogen-activated protein kinases, had no inhibitory effects on B4GALT1 expression. The knock-down of the B4GALT1 gene and the inhibition of membrane B4GALT1 function resulted in the significant inhibition of estrogen-induced proliferation of MCF-7 cells. Considering

  18. Genotypes of vitamin D and estrogen receptors in pre and perimenopausal women from Córdoba, Argentina.

    PubMed

    Ulla, María; Pérez, Adriana; Elías, Vanina; Binci, Miriam; Pretel, Esteban; Castro, María; Talamoni, Juan; Costero, Beatriz; Mammana, Mónica; Babini, Silvana; Díaz de Barboza, Gabriela; Tolosa de Talamoni, Nori

    2007-01-01

    The aim of this study was to determine the frequency of vitamin D receptor and estrogen receptor genotypes and their relationship with the lumbar spine or femoral neck bone mineral density in healthy pre and perimenopausal women from Córdoba (Argentina) and adjacent areas. Genotypes were assessed by restriction fragment length polymorphism-polymerase chain reaction technique. Bsm I and Fok I for vitamin D receptor gene and Xbal and Pvull for estrogen receptor gene were used as restrictases. Two hundred and ten healthy pre and perimenopausal women were recruited and analyzed by age. Calcemia and serum parathyroid hormone did not change, but serum P and beta-CrossLaps decreased with age. Femoral neck bone mineral density decreased significantly after 30 years old. Vitamin D receptor and estrogen receptor genotype frequencies were similar to those from other Caucasian women. No association between vitamin D receptor and estrogen receptor genotypes with the lumbar spine or femoral neck bone mineral density has been detected. Analysis of interaction between vitamin D receptor and estrogen receptor genes using covariates such as age, height and body mass index did not show any influence of the combination of those genotypes on bone mineral density. Lifestyle, smoking and alcohol intake had no effect on lumbar spine and femoral neck bone mineral density. To conclude, these data do not support the hypothesis that vitamin D receptor and estrogen receptor genotypes influence on lumbar spine and femoral neck bone mineral density in healthy pre and perimenopausal women from this area of Argentina.

  19. MODELING THE EFFECTS OF FLEXIBILITY ON THE BINDING OF ENVIRONMENTAL ESTROGENS TO THE ESTROGEN RECEPTOR

    EPA Science Inventory

    Modeling the effects of flexibility on the binding of environmental estrogens to the estrogen receptor
    There are many reports of environmental endocrine disruption in the literature, yet it has been difficult to identify the specific chemicals responsible for these effects. ...

  20. CERAPP: Collaborative Estrogen Receptor Activity Prediction Project

    PubMed Central

    Mansouri, Kamel; Abdelaziz, Ahmed; Rybacka, Aleksandra; Roncaglioni, Alessandra; Tropsha, Alexander; Varnek, Alexandre; Zakharov, Alexey; Worth, Andrew; Richard, Ann M.; Grulke, Christopher M.; Trisciuzzi, Daniela; Fourches, Denis; Horvath, Dragos; Benfenati, Emilio; Muratov, Eugene; Wedebye, Eva Bay; Grisoni, Francesca; Mangiatordi, Giuseppe F.; Incisivo, Giuseppina M.; Hong, Huixiao; Ng, Hui W.; Tetko, Igor V.; Balabin, Ilya; Kancherla, Jayaram; Shen, Jie; Burton, Julien; Nicklaus, Marc; Cassotti, Matteo; Nikolov, Nikolai G.; Nicolotti, Orazio; Andersson, Patrik L.; Zang, Qingda; Politi, Regina; Beger, Richard D.; Todeschini, Roberto; Huang, Ruili; Farag, Sherif; Rosenberg, Sine A.; Slavov, Svetoslav; Hu, Xin; Judson, Richard S.

    2016-01-01

    Background: Humans are exposed to thousands of man-made chemicals in the environment. Some chemicals mimic natural endocrine hormones and, thus, have the potential to be endocrine disruptors. Most of these chemicals have never been tested for their ability to interact with the estrogen receptor (ER). Risk assessors need tools to prioritize chemicals for evaluation in costly in vivo tests, for instance, within the U.S. EPA Endocrine Disruptor Screening Program. Objectives: We describe a large-scale modeling project called CERAPP (Collaborative Estrogen Receptor Activity Prediction Project) and demonstrate the efficacy of using predictive computational models trained on high-throughput screening data to evaluate thousands of chemicals for ER-related activity and prioritize them for further testing. Methods: CERAPP combined multiple models developed in collaboration with 17 groups in the United States and Europe to predict ER activity of a common set of 32,464 chemical structures. Quantitative structure–activity relationship models and docking approaches were employed, mostly using a common training set of 1,677 chemical structures provided by the U.S. EPA, to build a total of 40 categorical and 8 continuous models for binding, agonist, and antagonist ER activity. All predictions were evaluated on a set of 7,522 chemicals curated from the literature. To overcome the limitations of single models, a consensus was built by weighting models on scores based on their evaluated accuracies. Results: Individual model scores ranged from 0.69 to 0.85, showing high prediction reliabilities. Out of the 32,464 chemicals, the consensus model predicted 4,001 chemicals (12.3%) as high priority actives and 6,742 potential actives (20.8%) to be considered for further testing. Conclusion: This project demonstrated the possibility to screen large libraries of chemicals using a consensus of different in silico approaches. This concept will be applied in future projects related to other

  1. Estrogen binding, receptor mRNA, and biologic response in osteoblast-like osteosarcoma cells

    SciTech Connect

    Komm, B.S.; Terpening, C.M.; Benz, D.J.; Graeme, K.A.; Gallegos, A.; Korc, M.; Greene, G.L.; O'Malley, B.W.; Haussler, M.R.

    1988-07-01

    High specific activity estradiol labeled with iodine-125 was used to detect approximately 200 saturable, high-affinity (dissociation constant approximately equal to 1.0 nM) nuclear binding sites in rat (ROS 17/2.8) and human (HOS TE85) clonal osteoblast-like osteosarcoma cells. Of the steroids tested, only testosterone exhibited significant cross-reactivity with estrogen binding. RNA blot analysis with a complementary DNA probe to the human estrogen receptor revealed putative receptor transcripts of 6 to 6.2 kilobases in both rat and human osteosarcoma cells. Type I procollagen and transforming growth factor-beta messenger RNA levels were enhanced in cultured human osteoblast-like cells treated with 1 nM estradiol. Thus, estrogen can act directly on osteoblasts by a receptor-mediated mechanism and thereby modulate the extracellular matrix and other proteins involved in the maintenance of skeletal mineralization and remodeling.

  2. Estrogen Receptor Ligands: A Review (2013–2015)

    PubMed Central

    Farzaneh, Shabnam; Zarghi, Afshin

    2016-01-01

    Estrogen receptors (ERs) are a group of compounds named for their importance in both menstrual and estrous reproductive cycles. They are involved in the regulation of various processes ranging from tissue growth maintenance to reproduction. Their action is mediated through ER nuclear receptors. Two subtypes of the estrogen receptor, ERα and ERβ, exist and exhibit distinct cellular and tissue distribution patterns. In humans, both receptor subtypes are expressed in many cells and tissues, and they control key physiological functions in various organ systems. Estrogens attract great attention due to their wide applications in female reproductive functions and treatment of some estrogen-dependent cancers and osteoporosis. This paper provides a general review of ER ligands published in international journals patented between 2013 and 2015. The broad physiological profile of estrogens has attracted the attention of many researchers to develop new estrogen ligands as therapeutic molecules for various clinical purposes. After the discovery of the ERβ receptor, subtype-selective ligands could be used to elicit beneficial estrogen-like activities and reduce adverse side effects, based on the different distributions and relative levels of the two ER subtypes in different estrogen target tissues. Therefore, recent literature has focused on selective estrogen ligands as highly promising agents for the treatment of some types of cancer, as well as for cardiovascular, inflammatory, and neurodegenerative diseases. Estrogen receptors are nuclear transcription factors that are involved in the regulation of many complex physiological functions in humans. Selective estrogen ligands are highly promising targets for treatment of some types of cancer, as well as for cardiovascular, inflammatory and neurodegenerative diseases. Extensive structure-activity relationship studies of ER ligands based on small molecules indicate that many different structural scaffolds may provide high

  3. Maternal Regulation of Estrogen Receptor α Methylation

    PubMed Central

    Champagne, Frances A.; Curley, James P.

    2008-01-01

    Summary Advances in molecular biology have provided tools for studying the epigenetic factors which modulate gene expression. DNA methylation is an epigenetic modification which can have sustained effects on transcription and is associated with long-term gene silencing. In this review, we focus on the regulation of estrogen receptor alpha (ERα) expression by hormonal and environmental cues, the consequences of these cues for female maternal and sexual behavior and recent studies which explore the role of DNA methylation in mediating these developmental effects, with particular focus on the mediating role of maternal care. The methylation status of ERα has implications for reproductive behavior, cancer susceptibility and recovery from ischemic injury suggesting an epigenetic basis for risk and resilience across the life span. PMID:18644464

  4. Variations in the levels of estrogen receptors in prolactin producing pituitary tumor cells.

    PubMed

    Noteboom, W D; Durham, J B; Mitra, R

    1982-05-01

    The binding of [3H]-17 beta-estradiol in cells and cytoplasmic fractions of three different prolactin producing pituitary tumor lines was compared and found to vary widely. The concentration of estrogen receptors of the MtTW10 rat tumor line was high in early passages, but receptor levels decreased with subsequent passages in animals. Over a period of 12 months, the estrogen binding capacity in low speed supernatant fractions of cell homogenates decreased from 61.5 fmol [3H]-17 beta-estradiol per mg protein to less than 10 fmol [3H]-17 beta-estradiol per mg protein. A similar decrease in receptor concentration was found in MtTW10 cells which were adapted to in vitro culture. The concentration of receptor in low speed supernatant fractions of cultured GH3 rat tumor cells remained between 60 and 80 fmol [3H]-17 beta-estradiol per mg protein throughout the entire period of experimentation. In contrast, no high affinity receptors could be detected in similar fractions of the human pituitary cell line, 18-54, when cultured either in the presence or absence of serum. The Kd for the estradiol:receptor complex was determined to be 1.0 x 10(-10) M for receptors from MtTW10 cells and remained constant as the concentration of receptors declined. The receptors in both MtTW10 and GH3 cells were found to exist as 8s molecular species which are converted to 4s species by a temperature dependent process. The binding of estrogen to 8s and 4s receptors at 4 degrees C was shown to occur in the presence of 3 mg/ml of digitonin.

  5. Cloning and functional characterization of Chondrichthyes, cloudy catshark, Scyliorhinus torazame and whale shark, Rhincodon typus estrogen receptors.

    PubMed

    Katsu, Yoshinao; Kohno, Satomi; Narita, Haruka; Urushitani, Hiroshi; Yamane, Koudai; Hara, Akihiko; Clauss, Tonya M; Walsh, Michael T; Miyagawa, Shinichi; Guillette, Louis J; Iguchi, Taisen

    2010-09-15

    Sex-steroid hormones are essential for normal reproductive activity in both sexes in all vertebrates. Estrogens are required for ovarian differentiation during a critical developmental stage and promote the growth and differentiation of the female reproductive system following puberty. Recent studies have shown that environmental estrogens influence the developing reproductive system as well as gametogenesis, especially in males. To understand the molecular mechanisms of estrogen actions and to evaluate estrogen receptor-ligand interactions in Elasmobranchii, we cloned a single estrogen receptor (ESR) from two shark species, the cloudy catshark (Scyliorhinus torazame) and whale shark (Rhincodon typus) and used an ERE-luciferase reporter assay system to characterize the interaction of these receptors with steroidal and other environmental estrogens. In the transient transfection ERE-luciferase reporter assay system, both shark ESR proteins displayed estrogen-dependent activation of transcription, and shark ESRs were more sensitive to 17beta-estradiol compared with other natural and synthetic estrogens. Further, the environmental chemicals, bisphenol A, nonylphenol, octylphenol and DDT could activate both shark ESRs. The assay system provides a tool for future studies examining the receptor-ligand interactions and estrogen disrupting mechanisms in Elasmobranchii.

  6. Estrogen receptor-alpha gene expression in the cortex: sex differences during development and in adulthood.

    PubMed

    Wilson, Melinda E; Westberry, Jenne M; Trout, Amanda L

    2011-03-01

    17β-estradiol is a hormone with far-reaching organizational, activational and protective actions in both male and female brains. The organizational effects of early estrogen exposure are essential for long-lasting behavioral and cognitive functions. Estradiol mediates many of its effects through the intracellular receptors, estrogen receptor-alpha (ERα) and estrogen receptor-beta (ERβ). In the rodent cerebral cortex, estrogen receptor expression is high early in postnatal life and declines dramatically as the animal approaches puberty. This decline is accompanied by decreased expression of ERα mRNA. This change in expression is the same in both males and females in the developing isocortex and hippocampus. An understanding of the molecular mechanisms involved in the regulation of estrogen receptor alpha (ERα) gene expression is critical for understanding the developmental, as well as changes in postpubertal expression of the estrogen receptor. One mechanism of suppressing gene expression is by the epigenetic modification of the promoter regions by DNA methylation that results in gene silencing. The decrease in ERα mRNA expression during development is accompanied by an increase in promoter methylation. Another example of regulation of ERα gene expression in the adult cortex is the changes that occur following neuronal injury. Many animal studies have demonstrated that the endogenous estrogen, 17β-estradiol, is neuroprotective. Specifically, low levels of estradiol protect the cortex from neuronal death following middle cerebral artery occlusion (MCAO). In females, this protection is mediated through an ERα-dependent mechanism. ERα expression is rapidly increased following MCAO in females, but not in males. This increase is accompanied by a decrease in methylation of the promoter suggesting a return to the developmental program of gene expression within neurons. Taken together, during development and in adulthood, regulation of ERα gene expression in the

  7. Effects of ovarian hormones on beta-adrenergic and muscarinic receptors in rat heart

    SciTech Connect

    Klangkalya, B.; Chan, A.

    1988-01-01

    The in vitro and in vivo effects of estrogen and progesterone on muscarinic and ..beta..-adrenergic receptors of cardiac tissue were studied in ovariectomized (OVX) rats. The binding assay for muscarinic receptors was performed under a nonequilibrium condition; whereas the binding assay for ..beta..-adrenergic receptors, under an equilibrium condition. Estrogenic compounds and progesterone were found to have no effect on the binding of the radioligand, (/sup 3/H)-dihydroalprenolol, to ..beta..-adrenergic receptors in vitro. However, progestins but not estrogenic compounds inhibited the binding of the radioligand, (/sup 3/H)-quinuclidinyl benzilate, to muscarinic receptors in vitro, with progesterone as the most potent inhibitor. Progesterone was found to decrease the apparent affinity of muscarinic receptors for (/sup 3/H)(-)QNB in vitro. Daily treatment of OVX rats with estradiol benzoate or progesterone for 4 days had no effect on the muscarinic or ..beta..-adrenergic receptors with respect to the binding affinity and receptor density. However, administrations of these hormones together for 4 days caused an increase in the receptor density of muscarinic receptors without a significant effect on their apparent binding affinity; also these hormones induced a decrease in the binding affinity and an increase in the receptor density of ..beta..-adrenergic receptors.

  8. Molecular Cloning, Characterization, and Chromosome Mapping of Reptilian Estrogen Receptors

    PubMed Central

    Katsu, Yoshinao; Matsubara, Kazumi; Kohno, Satomi; Matsuda, Yoichi; Toriba, Michihisa; Oka, Kaori; Guillette, Louis J.; Ohta, Yasuhiko; Iguchi, Taisen

    2010-01-01

    In many vertebrates, steroid hormones are essential for ovarian differentiation during a critical developmental stage as well as promoting the growth and differentiation of the adult female reproductive system. Although studies have been extensively conducted in mammals and a few fish, amphibians, and bird species, the molecular mechanisms of sex steroid hormone (estrogens) action have been poorly examined in reptiles. Here, we evaluate hormone receptor and ligand interactions in two species of snake, the Okinawa habu (Protobothrops flavoviridis, Viperidae) and the Japanese four-striped rat snake (Elaphe quadrivirgata, Colubridae) after the isolation of cDNAs encoding estrogen receptor α (ESR1) and estrogen receptor β (ESR2). Using a transient transfection assay with mammalian cells, the transcriptional activity of reptilian (Okinawa habu, Japanese four-striped rat snake, American alligator, and Florida red-belly freshwater turtle) ESR1 and ESR2 was examined. All ESR proteins displayed estrogen-dependent activation of transcription via an estrogen-response element-containing promoter; however, the responsiveness to various estrogens was different. Further, we determined the chromosomal locations of the snake steroid hormone receptor genes. ESR1 and ESR2 genes were localized to the short and long arms of chromosome 1, respectively, whereas androgen receptor was localized to a pair of microchromosomes in the two snake species examined. These data provide basic tools that allow future studies examining receptor-ligand interactions and steroid endocrinology in snakes and also expands our knowledge of sex steroid hormone receptor evolution. PMID:20926589

  9. G protein-coupled receptor 30 is an estrogen receptor in the plasma membrane

    SciTech Connect

    Funakoshi, Takeshi; Yanai, Akie; Shinoda, Koh; Kawano, Michio M.; Mizukami, Yoichi . E-mail: mizukami@yamaguchi-u.ac.jp

    2006-08-04

    Recently, GPR30 was reported to be a novel estrogen receptor; however, its intracellular localization has remained controversial. To investigate the intracellular localization of GPR30 in vivo, we produced four kinds of polyclonal antibodies for distinct epitopes on GPR30. Immunocytochemical observations using anti-GPR30 antibody and anti-FLAG antibody show that FLAG-GPR30 localizes to the plasma membrane 24 h after transfection. Treatment with estrogen (17{beta}-estradiol or E2) causes an elevation in the intracellular Ca{sup 2+} concentration ([Ca{sup 2+}]{sub i}) within 10 s in HeLa cells expressing FLAG-GPR30. In addition, E2 induces the translocation of GPR30 from the plasma membrane to the cytoplasm by 1 h after stimulation. Immunohistochemical analysis shows that GPR30 exists on the cell surface of CA2 pyramidal neuronal cells. The images on transmission electron microscopy show that GPR30 is localized to a particular region associated with the plasma membranes of the pyramidal cells. These data indicate that GPR30, a transmembrane receptor for estrogen, is localized to the plasma membrane of CA2 pyramidal neuronal cells of the hippocampus in rat brain.

  10. SPONTANEOUS AIRWAY HYPERRESPONSIVENESS IN ESTROGEN RECEPTOR-A DEFICIENT MICE

    EPA Science Inventory

    Rationale: Airway hyperresponsiveness is a critical feature of asthma. Substantial epidemiologic evidence supports a role for female sex hormones in modulating lung function and airway hyperresponsiveness in humans. Objectives: To examine the role of estrogen receptors in modulat...

  11. Estrogenic Compounds, Estrogen Receptors and Vascular Cell Signaling in the Aging Blood Vessels

    PubMed Central

    Smiley, Dia A.; Khalil, Raouf A.

    2010-01-01

    The cardiovascular benefits of menopausal hormone therapy (MHT) remain controversial. The earlier clinical observations that cardiovascular disease (CVD) was less common in MHT users compared to non-users suggested cardiovascular benefits of MHT. Also, experimental studies have identified estrogen receptors ERα, ERβ and GPR30, which mediate genomic or non-genomic effects in vascular endothelium, smooth muscle, and extracellular matrix (ECM). However, data from randomized clinical trials (RCTs), most notably the Women's Health Initiative (WHI) study, have challenged the cardiovascular benefits and highlighted adverse cardiovascular events with MHT. The discrepancies have been attributed to the design of RCTs, the subjects' advanced age and preexisting CVD, and the form of estrogen used. The discrepancies may also stem from age-related changes in vascular ER amount, distribution, integrity, and post-receptor signaling pathways as well as structural changes in the vasculature. Age-related changes in other sex hormones such as testosterone may also alter the hormonal environment and influence the cardiovascular effects of estrogen. Investigating the chemical properties, structure-activity relationship and pharmacology of natural and synthetic estrogens should improve the effectiveness of conventional MHT. Further characterization of phytoestrogens, selective estrogen-receptor modulators (SERMs), and specific ER agonists may provide substitutes to conventional MHT. Conditions with excess or low estrogen levels such as polycystic ovary syndrome (PCOS) and Turner syndrome may provide insight into the development and regulation of ER and the mechanisms of aberrant estrogen-ER interactions. The lessons learned from previous RCTs have led to more directed studies such as the Kronos Early Estrogen Prevention Study (KEEPS). Careful design of experimental models and RCTs, coupled with the development of specific ER modulators, hold the promise of improving the actions of

  12. In Vivo Imaging of Activated Estrogen Receptors in Utero by Estrogens and Bisphenol A

    PubMed Central

    Lemmen, Josephine G.; Arends, Roel J.; van der Saag, Paul T.; van der Burg, Bart

    2004-01-01

    Environmental estrogens are of particular concern when exposure occurs during embryonic development. Although there are good models to study estrogenic activity of chemicals in adult animals, developmental exposure is much more difficult to test. The weak estrogenic activity of the environmental estrogen bisphenol A (BPA) in embryos is controversial. We have recently generated transgenic mice that carry a reporter construct with estrogen-responsive elements coupled to luciferase. We show that, using this in vivo model in combination with the IVIS imaging system, activation of estrogen receptors (ERs) by maternally applied BPA and other estrogens can be detected in living embryos in utero. Eight hours after exposure to 1 mg/kg BPA, ER transactivation could be significantly induced in the embryos. This was more potent than would be estimated from in vitro assays, although its intrinsic activity is still lower than that of diethylstilbestrol and 17β-estradiol dipropionate. On the basis of these results, we conclude that the estrogenic potency of BPA estimated using in vitro assays might underestimate its estrogenic potential in embryos. PMID:15531440

  13. Characterization and Consequences of Estrogen Receptor Exon Five Deletion.

    DTIC Science & Technology

    1997-08-01

    the assembly of an adhesion belt (whose contraction has been implicated in lumen formation during gland development) [17], and tight junctions...down regulation by gonadotropins. Molecular Endocrinology, 1997. 11: p. 172-182. 87. Kuiper , G., et al., Cloning of a novel estrogen receptor...and K. Korach, Editorial: A new actor in the estrogen receptor drama - enter ER-B3. Endocrinology, 1997. 138(3): p. 861-862. 90. Kuiper , G.G.J.M., et

  14. Novel Promising Estrogenic Receptor Modulators: Cytotoxic and Estrogenic Activity of Benzanilides and Dithiobenzanilides.

    PubMed

    Kucinska, Malgorzata; Giron, Maria-Dolores; Piotrowska, Hanna; Lisiak, Natalia; Granig, Walter H; Lopez-Jaramillo, Francisco-Javier; Salto, Rafael; Murias, Marek; Erker, Thomas

    2016-01-01

    The cytotoxicity of 27 benzanilides and dithiobenzanilides built on a stilbene scaffold and possessing various functional groups in aromatic rings previously described for their spasmolytic properties was assayed on three human cancer cell lines (A549 -lung adenocarcinoma, MCF-7 estrogen dependent breast adenocarcinoma and MDA-MB-231 estrogen independent breast adenocarcinoma) and 2 non-tumorigenic cell lines (CCD39Lu-lung fibroblasts, MCF-12A - breast epithelial). Three compounds (6, 15 and 18) showed selective antiproliferative activity against estrogen dependent MCF-7 cancer cells and their estrogenic activity was further confirmed in MCF-7 transfected with an estrogen receptor reporter plasmid and in HEK239 cells over-expressing the estrogen receptor alpha (ERα). Compound 18 is especially interesting as a potential candidate for therapy since it is highly toxic and selective towards estrogen dependent MCF7 cell lines (IC50 = 5.07 μM versus more than 100 μM for MDA-MB-231) and almost innocuous for normal breast cells (IC50 = 91.46 μM for MCF-12A). Docking studies have shown that compound 18 interacts with the receptor in the same cavity as estradiol although the extra aromatic ring is involved in additional binding interactions with residue W383. The role of W383 and the extended binding mode were confirmed by site-directed mutagenesis.

  15. Novel Promising Estrogenic Receptor Modulators: Cytotoxic and Estrogenic Activity of Benzanilides and Dithiobenzanilides

    PubMed Central

    Kucinska, Malgorzata; Giron, Maria-Dolores; Piotrowska, Hanna; Lisiak, Natalia; Granig, Walter H.; Lopez-Jaramillo, Francisco-Javier; Salto, Rafael; Murias, Marek; Erker, Thomas

    2016-01-01

    The cytotoxicity of 27 benzanilides and dithiobenzanilides built on a stilbene scaffold and possessing various functional groups in aromatic rings previously described for their spasmolytic properties was assayed on three human cancer cell lines (A549 –lung adenocarcinoma, MCF-7 estrogen dependent breast adenocarcinoma and MDA-MB-231 estrogen independent breast adenocarcinoma) and 2 non-tumorigenic cell lines (CCD39Lu–lung fibroblasts, MCF-12A - breast epithelial). Three compounds (6, 15 and 18) showed selective antiproliferative activity against estrogen dependent MCF-7 cancer cells and their estrogenic activity was further confirmed in MCF-7 transfected with an estrogen receptor reporter plasmid and in HEK239 cells over-expressing the estrogen receptor alpha (ERα). Compound 18 is especially interesting as a potential candidate for therapy since it is highly toxic and selective towards estrogen dependent MCF7 cell lines (IC50 = 5.07 μM versus more than 100 μM for MDA-MB-231) and almost innocuous for normal breast cells (IC50 = 91.46 μM for MCF-12A). Docking studies have shown that compound 18 interacts with the receptor in the same cavity as estradiol although the extra aromatic ring is involved in additional binding interactions with residue W383. The role of W383 and the extended binding mode were confirmed by site-directed mutagenesis. PMID:26730945

  16. Estrogenic potencies of resorcylic acid lactones and 17 beta-estradiol in female rats.

    PubMed

    Everett, D J; Perry, C J; Scott, K A; Martin, B W; Terry, M K

    1987-01-01

    Uterotrophic response in sexually immature female rats has been used to rank the relative estrogenic potencies of six resorcylic acid lactones (RALs) and to compare their activities with that of 17 beta-estradiol. On oral administration, the estrogenic potency relative to 17 beta-estradiol is as follows: 7 alpha-zearalenol, 10 times less; zeranol, 150 times less; taleranol, 350 times less; zearalanone, 400 times less; zearalenone, 650 times less; 7 beta-zearalenol, 3500 times less. On subcutaneous administration, zeranol is 500 times less estrogenic than 17 beta-estradiol.

  17. Homology-modeled ligand-binding domains of medaka estrogen receptors and androgen receptors: A model system for the study of reproduction

    SciTech Connect

    Cui Jianzhou Shen Xueyan; Yan Zuowei; Zhao Haobin; Nagahama, Yoshitaka

    2009-02-27

    Estrogen and androgen and their receptors play critical roles in physiological processes such as sexual differentiation and development. Using the available structural models for the human estrogen receptors alpha and beta and androgen receptor as templates, we designed in silico agonist and antagonist models of medaka estrogen receptor (meER) alpha, beta-1, and beta-2, and androgen receptor (meAR) alpha and beta. Using these models, we studied (1) the structural relationship between the ligand-binding domains (LBDs) of ERs and ARs of human and medaka, and (2) whether medaka ER and AR can be potential models for studying the ligand-binding activities of various agonists and antagonists of these receptors by docking analysis. A high level of conservation was observed between the sequences of the ligand-binding domains of meER{alpha} and huER{alpha}, meER{beta}1 and huER{beta}, meER{beta}2, and huER{beta} with 62.8%, 66.4%, and 65.1% identity, respectively. The sequence conservation between meAR{alpha} and huAR, meAR{beta}, and huAR was found with 70.1% and 61.0% of identity, respectively. Thirty-three selected endocrine disrupting chemicals (EDCs), including both agonists and antagonists, were docked into the LBD of ER and AR, and the corresponding docking score for medaka models and human templates were calculated. In order to confirm the conservation of the overall geometry and the binding pocket, the backbone root mean square deviation (RMSD) for C{alpha} atoms was derived from the structure superposition of all 10 medaka homology models to the six human templates. Our results suggested conformational conservation between the ERs and ARs of medaka and human, Thus, medaka could be highly useful as a model system for studies involving estrogen and androgen interaction with their receptors.

  18. Fulvestrant, a selective estrogen receptor down-regulator, sensitizes estrogen receptor negative breast tumors to chemotherapy.

    PubMed

    Jiang, Donghai; Huang, Yuan; Han, Ning; Xu, Mingjie; Xu, Liang; Zhou, Lin; Wang, Shu; Fan, Weimin

    2014-05-01

    Drug resistance frequently results in poor prognosis and high 5-year recurrence rate in estrogen receptor-negative (ER-) breast cancer patients. Herein, we examined the reversal effects of fulvestrant on multidrug resistance (MDR) in ER- breast cancer cells. Co-administration of fulvestrant significantly sensitized ER- MDR tumors to paclitaxel both in vitro and in vivo. Further analyses indicated that fulvestrant did not affect P-gp expression, but could inhibit P-gp function and subsequently reverse P-gp mediated drug resistance in ER- breast cancer cells. These results showed that combination of fulvestrant and chemotherapeutic agents might provide an effective treatment for ER- MDR breast cancers.

  19. Estrogen receptor-related receptors in the killifish Fundulus heteroclitus: diversity, expression, and estrogen responsiveness.

    PubMed

    Tarrant, A M; Greytak, S R; Callard, G V; Hahn, M E

    2006-08-01

    The estrogen receptor-related receptors (ERRs) are a group of nuclear receptors that were originally identified on the basis of sequence similarity to the estrogen receptors. The three mammalian ERR genes have been implicated in diverse physiological processes ranging from placental development to maintenance of bone density, but the diversity, function, and regulation of ERRs in non-mammalian species are not well understood. In this study, we report the cloning of four ERR cDNAs from the Atlantic killifish, Fundulus heteroclitus, along with adult tissue expression and estrogen responsiveness. Phylogenetic analysis indicates that F. heteroclitus (Fh)ERRalpha is an ortholog of the single ERRalpha identified in mammals, pufferfish, and zebrafish. FhERRbetaa and FhERRbetab are co-orthologs of the mammalian ERRbeta. Phylogenetic placement of the fourth killifish ERR gene, tentatively identified as FhERRgammab, is less clear. The four ERRs showed distinct, partially overlapping mRNA expression patterns in adult tissues. FhERRalpha was broadly expressed. FhERRbetaa was expressed at apparently low levels in eye, brain, and ovary. FhERRbetab was expressed more broadly in liver, gonad, eye, brain, and kidney. FhERRgammab was expressed in multiple tissues including gill, heart, kidney, and eye. Distinct expression patterns of FhERRbetaa and FhERRbetab are consistent with subfunctionalization of the ERRbeta paralogs. Induction of ERRalpha mRNA by exogenous estrogen exposure has been reported in some mammalian tissues. In adult male killifish, ERR expression did not significantly change following estradiol injection, but showed a trend toward a slight induction (three- to five-fold) of ERRalpha expression in heart. In a second, more targeted experiment, expression of ERRalpha in adult female killifish was downregulated 2.5-fold in the heart following estradiol injection. In summary, our results indicate that killifish contain additional ERR genes relative to mammals, including

  20. ROLE OF ESTROGEN RECEPTOR-α ON FOOD DEMAND ELASTICITY

    PubMed Central

    Minervini, Vanessa; Rowland, Neil E.; Robertson, Kimberly L.; Foster, Thomas C.

    2016-01-01

    Estrogens have been shown to have an inhibitory effect on food intake under free-feeding conditions, yet the effects of estrogens on food-maintained operant responding have been studied to a much lesser extent and, thus, are not well understood. Therefore, the purpose of the present experiment was to use a behavioral economics paradigm to assess differences in demand elasticity between mice with knockout of the estrogen receptor subtype α, knockout of subtype β, and their wild type controls. The mice responded in a closed economy, and the price of food was increased by increasing the fixed-ratio response requirement every four sessions. Overall, we found that mice with the knockout of receptor subtype α had the most elastic demand functions. Therefore, under these conditions, estrogens increased food seeking via activation of the receptor subtype α. The results were inconsistent with those reported by previous studies that employed free-feeding conditions. PMID:25869426

  1. Role of estrogen receptor-α on food demand elasticity.

    PubMed

    Minervini, Vanessa; Rowland, Neil E; Robertson, Kimberly L; Foster, Thomas C

    2015-05-01

    Estrogens have been shown to have an inhibitory effect on food intake under free-feeding conditions, yet the effects of estrogens on food-maintained operant responding have been studied to a much lesser extent and, thus, are not well understood. Therefore, the purpose of the present experiment was to use a behavioral economics paradigm to assess differences in demand elasticity between mice with knockout of the estrogen receptor subtype α, knockout of subtype β, and their wild type controls. The mice responded in a closed economy, and the price of food was increased by increasing the fixed-ratio response requirement every four sessions. Overall, we found that mice with the knockout of receptor subtype α had the most elastic demand functions. Therefore, under these conditions, estrogens increased food seeking via activation of the receptor subtype α. The results were inconsistent with those reported by previous studies that employed free-feeding conditions.

  2. Delayed puberty and estrogen resistance in a woman with estrogen receptor α variant.

    PubMed

    Quaynor, Samuel D; Stradtman, Earl W; Kim, Hyung-Goo; Shen, Yiping; Chorich, Lynn P; Schreihofer, Derek A; Layman, Lawrence C

    2013-07-11

    Although androgen resistance has been characterized in men with a normal chromosome complement and mutations in the androgen-receptor gene, a mutation in the gene encoding estrogen receptor α (ESR1) was previously described only in one man and not, to our knowledge, in a woman. We now describe an 18-year-old woman without breast development and with markedly elevated serum levels of estrogens and bilateral multicystic ovaries. She was found to have a homozygous loss-of-function ESR1 mutation in a completely conserved residue that interferes with estrogen signaling. Her clinical presentation was similar to that in the mouse orthologue knockout. This case shows that disruption of ESR1 causes profound estrogen resistance in women. (Funded by the National Institutes of Health.).

  3. The Molecular, Cellular and Clinical Consequences of Targeting the Estrogen Receptor Following Estrogen Deprivation Therapy

    PubMed Central

    Fan, Ping; Maximov, Philipp Y.; Curpan, Ramona F.; Abderrahman, Balkees; Jordan, V. Craig

    2015-01-01

    During the past twenty years our understanding of the control of breast tumor development, growth and survival has changed dramatically. The once long forgotten application of high dose synthetic estrogen therapy as the first chemical therapy to treat any cancer has been resurrected, refined and reinvented as the new biology of estrogen-induced apoptosis. High dose estrogen therapy was cast aside once tamoxifen, from its origins as a failed “morning after pill”, was reinvented as the first targeted therapy to treat any cancer. The current understanding of the mechanism of estrogen-induced apoptosis is described as a consequence of acquired resistance to long term antihormone therapy in estrogen receptor (ER) positive breast cancer. The ER signal transduction pathway remains a target for therapy in breast cancer despite “antiestrogen” resistance, but becomes a regulator of resistance. Multiple mechanisms of resistance come into play: Selective ER Modulator (SERM) stimulated growth, growth factor/ER crosstalk, estrogen-induced apoptosis and mutations of ER. But it is with the science of estrogen-induced apoptosis that the next innovation in women’s health will be developed. Recent evidence suggests that the glucocorticoid properties of medroxyprogesterone acetate blunt estrogen-induced apoptosis in estrogen deprived breast cancer cell populations. As a result breast cancer develops during long-term Hormone Replacement Therapy (HRT). A new synthetic progestin with estrogen-like properties, such as the 19 nortestosterone derivatives used in oral contraceptives, will continue to protect the uterus from unopposed estrogen stimulation but at the same time, reinforce apoptosis in vulnerable populations of nascent breast cancer cells. PMID:26052034

  4. Lycopene and other carotenoids inhibit estrogenic activity of 17beta-estradiol and genistein in cancer cells.

    PubMed

    Hirsch, Keren; Atzmon, Andrea; Danilenko, Michael; Levy, Joseph; Sharoni, Yoav

    2007-08-01

    Epidemiological evidence suggests that carotenoids prevent several types of cancer, including mammary and endometrial cancers. On the other hand, such studies have also shown that estrogens are the most important risk factors for these cancer types. Genistein, the phytoestrogen mainly found in soy, also shows significant estrogenic activity when tested at concentrations found in human blood. The aim of this study was to determine whether carotenoids inhibit signaling of steroidal estrogen and phytoestrogen which could explain their cancer preventive activity. Similar to the known effect of 17beta-estradiol (E(2)), treatment of breast (T47D and MCF-7) and endometrial (ECC-1) cancer cells with phytoestrogens induced cell proliferation, cell-cycle progression and transactivation of the estrogen response element (ERE). However, each of the tested carotenoids (lycopene, phytoene, phytofluene, and beta-carotene) inhibited cancer cell proliferation induced by either E(2) or genistein. The inhibition of cell growth by lycopene was accompanied by slow down of cell-cycle progression from G1 to S phase. Moreover, the carotenoids inhibited estrogen-induced transactivation of ERE that was mediated by both estrogen receptors (ERs) ERalpha and ERbeta. The possibility that this inhibition results from competition of carotenoid-activated transcription systems on a limited pool of shared coactivators with the ERE transcription system was tested. Although cotransfection of breast and endometrial cancer cells with four different coactivators (SRC-1, SRC-2, SRC-3, and DRIP) strongly stimulated ERE reporter gene activity, it did not oppose the inhibitory effect of carotenoids. These results suggest that dietary carotenoids inhibit estrogen signaling of both 17beta-estradiol and genistein, and attenuate their deleterious effect in hormone-dependent malignancies.

  5. Visualization of Estrogen Receptor Transcriptional Activation in Zebrafish

    PubMed Central

    Halpern, Marnie E.

    2011-01-01

    Estrogens regulate a diverse range of physiological processes and affect multiple tissues. Estrogen receptors (ERs) regulate transcription by binding to DNA at conserved estrogen response elements, and such elements have been used to report ER activity in cultured cells and in transgenic mice. We generated stable, transgenic zebrafish containing five consecutive elements upstream of a c-fos minimal promoter and green fluorescent protein (GFP) to visualize and quantify transcriptional activation in live larvae. Transgenic larvae show robust, dose-dependent estrogen-dependent fluorescent labeling in the liver, consistent with er gene expression, whereas ER antagonists inhibit GFP expression. The nonestrogenic steroids dexamethasone and progesterone fail to activate GFP, confirming ER selectivity. Natural and synthetic estrogens activated the transgene with varying potency, and two chemicals, genistein and bisphenol A, preferentially induce GFP expression in the heart. In adult fish, fluorescence was observed in estrogenic tissues such as the liver, ovary, pituitary gland, and brain. Individual estrogen-responsive neurons and their projections were visualized in the adult brain, and GFP-positive neurons increased in number after 17β-estradiol exposure. The transgenic estrogen-responsive zebrafish allow ER signaling to be monitored visually and serve as in vivo sentinels for detection of estrogenic compounds. PMID:21540282

  6. Photoperiod affects estrogen receptor α, estrogen receptor β and aggressive behavior

    PubMed Central

    Trainor, Brian C.; Rowland, Michael R.; Nelson, Randy J.

    2007-01-01

    Estrogens have important effects on male and female social behavior. Despite growing knowledge of the anatomy and behavioral effects of the two predominant estrogen receptor subtypes in mammals (ERα and ERβ), relatively little is known about how these receptors respond to salient environmental stimuli. Many seasonally breeding species respond to changing photoperiods that predict seasonal changes in resource availability. We characterized the effects of photoperiod on aggressive behavior in two species of Peromyscus that exhibit gonadal regression in short days. P. polionotus (old field mice) were more aggressive than P. maniculatus (deer mice) and both species were more aggressive in short days. We used immunocytochemistry and real-time polymerase chain reaction to characterize the effects of photoperiod on ERα and ERβ expression. In both species ERα-immunoreactive staining in the posterior bed nucleus of the stria terminalis (BNST) was increased in short vs. long days. Both species had reduced ERβ-immunoreactive expression in the posterior BNST in short days. In the medial amygdala ERβ immunoreactivity was increased in long days for both species. Using real-time polymerase chain reaction on punch samples that included the BNST, we observed that ERα mRNA was increased and ERβ mRNA was decreased in short days. These data suggest that the effects of photoperiod on ERα and ERβ expression may thus have important behavioral consequences. PMID:17614949

  7. Estrogen, vascular estrogen receptor and hormone therapy in postmenopausal vascular disease.

    PubMed

    Khalil, Raouf A

    2013-12-15

    Cardiovascular disease (CVD) is less common in premenopausal women than men of the same age or postmenopausal women, suggesting vascular benefits of estrogen. Estrogen activates estrogen receptors ERα, ERβ and GPR30 in endothelium and vascular smooth muscle (VSM), which trigger downstream signaling pathways and lead to genomic and non-genomic vascular effects such as vasodilation, decreased VSM contraction and growth and reduced vascular remodeling. However, randomized clinical trials (RCTs), such as the Women's Health Initiative (WHI) and Heart and Estrogen/progestin Replacement Study (HERS), have shown little vascular benefits and even adverse events with menopausal hormone therapy (MHT), likely due to factors related to the MHT used, ER profile, and RCT design. Some MHT forms, dose, combinations or route of administration may have inadequate vascular effects. Age-related changes in ER amount, distribution, integrity and post-ER signaling could alter the vascular response to MHT. The subject's age, preexisting CVD, and hormone environment could also reduce the effects of MHT. Further evaluation of natural and synthetic estrogens, phytoestrogens, and selective estrogen-receptor modulators (SERMs), and the design of appropriate MHT combinations, dose, route and 'timing' could improve the effectiveness of conventional MHT and provide alternative therapies in the peri-menopausal period. Targeting ER using specific ER agonists, localized MHT delivery, and activation of specific post-ER signaling pathways could counter age-related changes in ER. Examination of the hormone environment and conditions associated with hormone imbalance such as polycystic ovary syndrome may reveal the causes of abnormal hormone-receptor interactions. Consideration of these factors in new RCTs such as the Kronos Early Estrogen Prevention Study (KEEPS) could enhance the vascular benefits of estrogen in postmenopausal CVD.

  8. Estrogen, Vascular Estrogen Receptor and Hormone Therapy in Postmenopausal Vascular Disease

    PubMed Central

    Khalil, Raouf A.

    2013-01-01

    Cardiovascular disease (CVD) is less common in premenopausal women than men of the same age or postmenopausal women, suggesting vascular benefits of estrogen. Estrogen activates estrogen receptors ERα, ERβ and GPR30 in endothelium and vascular smooth muscle (VSM), which trigger downstream signaling pathways and lead to genomic and non-genomic vascular effects such as vasodilation, decreased VSM contraction and growth and reduced vascular remodeling. However, randomized clinical trials (RCTs), such as the Women’s Health Initiative (WHI) and Heart and Estrogen/progestin Replacement Study (HERS), have shown little vascular benefits and even adverse events with menopausal hormone therapy (MHT), likely due to factors related to the MHT used, ER profile, and RCT design. Some MHT forms, dose, combinations or route of administration may have inadequate vascular effects. Age-related changes in ER amount, distribution, integrity and post-ER signaling could alter the vascular response to MHT. The subject’s age, preexisting CVD, and hormone environment could also reduce the effects of MHT. Further evaluation of natural and synthetic estrogens, phytoestrogens, and selective estrogen-receptor modulators (SERMs), and the design of appropriate MHT combinations, dose, route and 'timing' could improve the effectiveness of conventional MHT and provide alternative therapies in the peri-menopausal period. Targeting ER using specific ER agonists, localized MHT delivery, and activation of specific post-ER signaling pathways could counter age-related changes in ER. Examination of the hormone environment and conditions associated with hormone imbalance such as polycystic ovary syndrome may reveal the causes of abnormal hormone-receptor interactions. Consideration of these factors in new RCTs such as the Kronos Early Estrogen Prevention Study (KEEPS) could enhance the vascular benefits of estrogen in postmenopausal CVD. PMID:24099797

  9. Estrogen Receptors and Their Implications in Colorectal Carcinogenesis

    PubMed Central

    Caiazza, Francesco; Ryan, Elizabeth J.; Doherty, Glen; Winter, Desmond C.; Sheahan, Kieran

    2015-01-01

    Upon binding their cognate receptors, ERα (ESR1) and ERβ (ESR2), estrogens activate intracellular signaling cascades that have important consequences for cellular behavior. Historically linked to carcinogenesis in reproductive organs, estrogens have also been implicated in the pathogenesis of different cancer types of non-reproductive tissues including the colon. ERβ is the predominant estrogen receptor expressed in both normal and malignant colonic epithelium. However, during colon cancer progression, ERβ expression is lost, suggesting that estrogen signaling may play a role in disease progression. Estrogens may in fact exert an anti-tumor effect through selective activation of pro-apoptotic signaling mediated by ERβ, inhibition of inflammatory signals and modulation of the tumor microenvironment. In this review, we analyze the estrogen pathway as a possible therapeutic avenue in colorectal cancer, we report the most recent experimental evidence to explain the cellular and molecular mechanisms of estrogen-mediated protection against colorectal tumorigenesis, and we discuss future challenges and potential avenues for targeted therapy. PMID:25699240

  10. Application of a yeast estrogen screen in non-biomarker species Varicorhinus barbatulus fish with two estrogen receptor subtypes to assess xenoestrogens.

    PubMed

    Fu, Keng-Yen; Chen, Chung-Yuan; Chang, Whei-Meih

    2007-06-01

    Xenoestrogens can interfere with normal estrogen signaling by competitively binding to the estrogen receptor (ER) and activating transcription of target genes. In this study, we cloned the estrogen receptor alpha (vbERalpha) and beta 2 (vbERbeta2) genes from liver of the indigenous Taiwanese cyprinid fish Varicorhinus barbatulus and tested the direct impact of several xenoestrogens on these ERs. Transcriptional activity of xenoestrogens was measured by the enzymatic activity of estrogen responsive element (ERE)-containing beta-galactosidase in a yeast reporter system. The xenoestrogens tested were phenol derivatives, DDT-related substances, phthalic acid esters, and polychlorinated biphenyls, with 17beta-estradiol (E2) as a subjective standard. The phenol derivatives [4-nonylphenol (4-NP), 4-t-octylphenol (4-t-OP) and bisphenol A (BPA)] exhibited significant dose-dependent responses in both ligand potency and ligand efficiency. Consistent with yeast assays using human or rainbow trout ERs, we observed a general subtype preference in that vbERalpha displayed higher relative potencies and efficiencies than vbERbeta2, although our assays induced a stronger response for xenoestrogens than did human or trout ERs. Whereas 4-NP and 4-t-OP have similar EC50 values relative to E2 for both ER subtypes, the strong estrogenic response of BPA markedly differentiates vbERalpha from vbERbeta2, suggesting possible species-specific BPA sensitivity. We report that the ameliorative yeast tool is readily applicable for indigenous wildlife studies of the bio-toxic influence of xenoestrogens with wildlife-specific estrogen receptors.

  11. Aryl hydrocarbon receptor-independent activation of estrogen receptor-dependent transcription by 3-methylcholanthrene.

    PubMed

    Shipley, Jonathan M; Waxman, David J

    2006-06-01

    Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that stimulates transcription directed by xenobiotic response elements upstream of target genes. Recently, AhR ligands were reported to induce formation of an AhR-estrogen receptor (ER) complex, which can bind to estrogen response elements (EREs) and stimulate transcription of ER target genes. Presently, we investigate the effect of the AhR ligands 3-methylcholanthrene (3MC), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 3,3',4,4',5-pentachlorobiphenyl (BZ126) on ERE-regulated luciferase reporter activity and endogenous ER target gene expression. In MCF-7 human breast cancer cells, 3MC induced transcription of ER reporter genes containing native promoter sequences of the ER-responsive genes complement 3 and pS2 and heterologous promoters regulated by isolated EREs. Dose-response studies revealed that the concentration of 3MC required to half-maximally activate transcription (EC(50)) was >100-fold higher for an ER reporter (27-57 muM) than for an AhR reporter (86-250 nM) in both MCF-7 cells and in human endometrial cancer Ishikawa cells. 3MC also stimulated expression of the endogenous ER target genes amphiregulin, cathepsin D and progesterone receptor, albeit to a much lower extent than was achieved following stimulation with 17beta-estradiol. In Ishikawa cells, 3MC, but not BZ126 or TCDD, stimulated ERalpha-dependent reporter activity but did not induce expression of endogenous ER target genes. Finally, studies carried out in the AhR-positive rat hepatoma cell line 5L and the AhR-deficient variant BP8 demonstrated that ER reporter activity could be induced by 3MC in a manner that was independent of AhR and thus distinct from the AhR-ER 'hijacking' mechanism described recently. 3MC may thus elicit estrogenic activity by multiple mechanisms.

  12. Characterization and Consequences of Estrogen Receptor Exon Five Deletion.

    DTIC Science & Technology

    1998-08-01

    adhesion belt (whose 127 contraction has been implicated in lumen formation during gland development) (17), and tight junctions (necessary for...G.G.J.M. Kuiper , J.-A. Gustafsson, and O.-K. Park-Sarge, Estrogen receptor-fl mRNA expression in rat ovary: down regulation by gonadotropins...Molecular Endocrinology, 1997. 11: p. 172-182. 87. Kuiper , G., E. Enmark, M. Pelto-Huikko, S. Nilsson, and J.-A. Gustafsson, Cloning of a novel estrogen

  13. Functional associations between two estrogen receptors, environmental estrogens, and sexual disruption in the roach (Rutilus rutilus).

    PubMed

    Katsu, Yoshinao; Lange, Anke; Urushitani, Hiroshi; Ichikawa, Rie; Paull, Gregory C; Cahill, Laura L; Jobling, Susan; Tyler, Charles R; Iguchi, Taisen

    2007-05-01

    Wild male roach (Rutilus rutilus) living in U.K. rivers contaminated with estrogenic effluents from wastewater treatment works show feminized responses and have a reduced reproductive capability, but the chemical causation of sexual disruption in the roach has not been established. Feminized responses were induced in male roach exposed to environmentally relevant concentrations of the pharmaceutical estrogen 17alpha-ethinylestradiol, EE2 (up to 4 ng/ L), during early life (from fertilization to 84 days posthatch, dph), and these effects were signaled by altered patterns of expression of two cloned roach estrogen receptor (ER) subtypes, ERalpha. and ERbeta, in the brain and gonad/ liver. Transactivation assays were developed for both roach ER subtypes and the estrogenic potencies of steroidal estrogens differed markedly at the different ER subtypes. EE2 was by far the most potent chemical, and estrone (E1, the most prevalent environmental steroid in wastewater discharges) was equipotent with estradiol (E2) in activating the ERs. Comparison of the EC50 values for the compounds tested showed that ERbeta was 3-21-fold more sensitive to natural steroidal estrogens and 54-fold more sensitive to EE2 as compared to ERalpha. These findings add substantial support to the hypothesis that steroidal estrogens play a significant role in the induction of intersex in roach populations in U.K. rivers and that the molecular approach described could be usefully applied to understand interspecies sensitivity to xenoestrogens.

  14. Comparative analysis of the interaction of various estrogens with the estrogen-receptor system of the uterus

    SciTech Connect

    Fanchenko, N.D.; Alekseeva, M.L.; Minina, L.S.; Novikov, E.A.; Khel'mun, D.K.

    1986-05-20

    The binding of various labeled estrogens under conditions of equilibrium in the cytosol of the uterus of sexually immature Wistar rats was studied. An analysis of the data obtained, as well as the kinetics of the dissociation of the complexes of the ligands used with specific high-affinity estrogen-binding sites of the cytosol, suggested that the population of estrogen receptors in the rat uterus is homogeneous. The possibility of intracellular regulation of the action of estrogens in the target cell in the presence of a homogeneous population of receptors, both at the receptor and at the post-receptor stages, is suggested.

  15. Potential of Selective Estrogen Receptor Modulators as Treatments and Preventives of Breast Cancer

    PubMed Central

    Peng, Jing; Sengupta, Surojeet; Jordan, V Craig

    2013-01-01

    Estrogen plays vital roles in human health and diseases. Estrogen mediates its actions almost entirely by binding to estrogen receptors (ER), alpha and beta which further function as transcription factors. Selective estrogen receptor modulators (SERMs) are synthetic molecules which bind to ER and can modulate its transcriptional capabilities in different ways in diverse estrogen target tissues. Tamoxifen, the prototypical SERM, is extensively used for targeted therapy of ER positive breast cancers and is also approved as the first chemo-preventive agent for lowering breast cancer incidence in high risk women. The therapeutic and preventive efficacy of tamoxifen was initially proven by series of experiments in the laboratory which laid the foundation of its clinical use. Unfortunately, use of tamoxifen is associated with de-novo and acquired resistance and some undesirable side effects. The molecular study of the resistance provides an opportunity to precisely understand the mechanism of SERM action which may further help in designing new and improved SERMs. Recent clinical studies reveal that another SERM, raloxifene, which is primarily used to treat post-menopausal osteoporosis, is as efficient as tamoxifen in preventing breast cancers with fewer side effects. Overall, these findings open a new horizon for SERMs as a class of drug which not only can be used for therapeutic and preventive purposes of breast cancers but also for various other diseases and disorders. Major efforts are therefore directed to make new SERMs with a better therapeutic profile and fewer side effects. PMID:19519291

  16. Artemisinin selectively decreases functional levels of estrogen receptor-alpha and ablates estrogen-induced proliferation in human breast cancer cells.

    PubMed

    Sundar, Shyam N; Marconett, Crystal N; Doan, Victor B; Willoughby, Jamin A; Firestone, Gary L

    2008-12-01

    MCF7 cells are an estrogen-responsive human breast cancer cell line that expresses both estrogen receptor (ER) alpha and ERbeta. Treatment of MCF7 cells with artemisinin, an antimalarial phytochemical from the sweet wormwood plant, effectively blocked estrogen-stimulated cell cycle progression induced by either 17beta-estradiol (E(2)), an agonist for both ERs, or by propyl pyrazole triol (PPT), a selective ERalpha agonist. Artemisinin strongly downregulated ERalpha protein and transcripts without altering expression or activity of ERbeta. Transfection of MCF7 cells with ERalpha promoter-linked luciferase reporter plasmids revealed that the artemisinin downregulation of ERalpha promoter activity accounted for the loss of ERalpha expression. Artemisinin treatment ablated the estrogenic induction of endogenous progesterone receptor (PR) transcripts by either E(2) or PPT and inhibited the estrogenic stimulation of a luciferase reporter plasmid driven by consensus estrogen response elements (EREs). Chromatin immunoprecipitation assays revealed that artemisinin significantly downregulated the level of endogeneous ERalpha bound to the PR promoter, whereas the level of bound endogeneous ERbeta was not altered. Treatment of MCF7 cells with artemisinin and the pure antiestrogen fulvestrant resulted in a cooperative reduction of ERalpha protein levels and enhanced G(1) cell cycle arrest compared with the effects of either compound alone. Our results show that artemisinin switches proliferative human breast cancer cells from expressing a high ERalpha:ERbeta ratio to a condition in which ERbeta predominates, which parallels the physiological state linked to antiproliferative events in normal mammary epithelium.

  17. Mechanism of the estrogen receptor interaction with 4-hydroxytamoxifen

    SciTech Connect

    Sasson, S.; Notides, A.C.

    1988-04-01

    The binding mechanism of the estrogen receptor with 4-(/sup 3/H)hydroxytamoxifen was investigated. The equilibrium binding analysis with 4-(/sup 3/H)hydroxytamoxifen indicated a positive cooperative interaction: the Scatchard plot was convex and the Hill coefficient was 1.4-1.5. This binding appears similar to the positively cooperative interaction of the estrogen receptor with (/sup 3/H)estradiol. However, a competitive binding assay with a saturating concentration of (/sup 3/H) estradiol and variable concentrations of 4-hydroxytamoxifen produced nonparallel displacement curves indicating that the binding mechanism of the receptor with these two ligands is different. The competitive binding assay with (/sup 3/H)estradiol and 4-hydroxytamoxifen at constant molar ratios demonstrated that the receptor's affinity for estradiol was reduced and the receptor preferentially bound 4-hydroxytamoxifen. These data suggest that 4-hydroxytamoxifen interacts with the receptor differently than estradiol; it antagonizes the binding of estradiol when these two ligands are simultaneously present.

  18. Glyphosate induces human breast cancer cells growth via estrogen receptors.

    PubMed

    Thongprakaisang, Siriporn; Thiantanawat, Apinya; Rangkadilok, Nuchanart; Suriyo, Tawit; Satayavivad, Jutamaad

    2013-09-01

    Glyphosate is an active ingredient of the most widely used herbicide and it is believed to be less toxic than other pesticides. However, several recent studies showed its potential adverse health effects to humans as it may be an endocrine disruptor. This study focuses on the effects of pure glyphosate on estrogen receptors (ERs) mediated transcriptional activity and their expressions. Glyphosate exerted proliferative effects only in human hormone-dependent breast cancer, T47D cells, but not in hormone-independent breast cancer, MDA-MB231 cells, at 10⁻¹² to 10⁻⁶M in estrogen withdrawal condition. The proliferative concentrations of glyphosate that induced the activation of estrogen response element (ERE) transcription activity were 5-13 fold of control in T47D-KBluc cells and this activation was inhibited by an estrogen antagonist, ICI 182780, indicating that the estrogenic activity of glyphosate was mediated via ERs. Furthermore, glyphosate also altered both ERα and β expression. These results indicated that low and environmentally relevant concentrations of glyphosate possessed estrogenic activity. Glyphosate-based herbicides are widely used for soybean cultivation, and our results also found that there was an additive estrogenic effect between glyphosate and genistein, a phytoestrogen in soybeans. However, these additive effects of glyphosate contamination in soybeans need further animal study.

  19. p150/Glued Modifies Nuclear Estrogen Receptor Function

    PubMed Central

    Lee, Soo Jung; Chae, Christina; Wang, Michael M.

    2009-01-01

    Estrogen modulates gene expression through interactions with estrogen receptors (ERs) that bind chromosomal target genes. Recent studies have suggested an interaction between the cytoskeletal system and estrogen signaling; these have implicated a role of cytoplasmic microtubules in scaffolding ERα and enhancing nongenomic function; in addition, other experiments demonstrate that dynein light chain 1 may chaperone ERα to the nucleus, indirectly increasing transcriptional potency. Actin/myosin and dynein light chain 1 are also required for estrogen-mediated chromosomal movement that is required for transcriptional up-regulation of ERα targets. We present evidence that the dynactin component, p150/glued, directly influences the potency of nuclear ER function. Increasing the stoichiometric ratio of p150/glued and ERα by overexpression enhances estrogen responses. ERα enhancement by p150/glued does not appear to be influenced by shifts in subcellular localization because microtubule disruption fails to increase nuclear ERα. Rather, we find that modest amounts of p150/glued reside in the nucleus of cells, suggesting that it plays a direct role in nuclear transcription. Notably, p150/glued is recruited to the pS2 promoter in the presence of hormone, and, in MCF-7 cells, knockdown of p150/glued levels reduces estrogen-dependent transcription. Our results suggest that p150/glued modulates estrogen sensitivity in cells through nuclear mechanisms. PMID:19228793

  20. Phytoestrogens from Psoralea corylifolia reveal estrogen receptor-subtype selectivity.

    PubMed

    Xin, D; Wang, H; Yang, J; Su, Y-F; Fan, G-W; Wang, Y-F; Zhu, Y; Gao, X-M

    2010-02-01

    The seed of Psoralea corylifolia L. (PCL), a well-known traditional Chinese medicine, has been applied as a tonic or an aphrodisiac agent and commonly used as a remedy for bone fracture, osteomalacia and osteoporosis in China. In our study, the estrogen receptor subtype-selective activities of the extracts and compounds derived from PCL were analyzed using the HeLa cell assay. The different fractions including petroleum ether, CH(2)Cl(2) and EtOAc fractions of the EtOH extract of PCL showed significant activity in activating either ERalpha or ERbeta whereas the n-BuOH fraction showed no estrogenic activity. Further chromatographic purification of the active fractions yielded seven compounds including the two coumarins isopsoralen and psoralen, the four flavonoids isobavachalcone, bavachin, corylifol A and neobavaisoflavone, and the meroterpene phenol, bakuchiol. In reporter gene assay, the two coumarins (10(-8)-10(-5)M) acted as ERalpha-selective agonists while the other compounds (10(-9)-10(-6)M) activated both ERalpha and ERbeta. The estrogenic activities of all compounds could be completely suppressed by the pure estrogen antagonist, ICI 182,780, suggesting that the compounds exert their activities through ER. Only psoralen and isopsoralen as ERalpha agonists promoted MCF-7 cell proliferation significantly. Although all the compounds have estrogenic activity, they may exert different biological effects. In conclusion, both ER subtype-selective and nonselective activities in compounds derived from PCL suggested that PCL could be a new source for selective estrogen-receptor modulators.

  1. Estrogen-related receptor β (ERRβ) - renaissance receptor or receptor renaissance?

    PubMed

    Divekar, Shailaja D; Tiek, Deanna M; Fernandez, Aileen; Riggins, Rebecca B

    2016-01-01

    Estrogen-related receptors (ERRs) are founding members of the orphan nuclear receptor (ONR) subgroup of the nuclear receptor superfamily. Twenty-seven years of study have yet to identify cognate ligands for the ERRs, though they have firmly placed ERRα and ERRγ at the intersection of cellular metabolism and oncogenesis. The pace of discovery for novel functions of ERRβ, however, has until recently been somewhat slower than that of its family members. ERRβ has also been largely ignored in summaries and perspectives of the ONR literature. Here, we provide an overview of established and emerging knowledge of ERRβ in mouse, man, and other species, highlighting unique aspects of ERRβ biology that set it apart from the other two estrogen-related receptors, with a focus on the impact of alternative splicing on the structure and function of this receptor.

  2. Estrogen-related receptor β (ERRβ) – renaissance receptor or receptor renaissance?

    PubMed Central

    Divekar, Shailaja D.; Tiek, Deanna M.; Fernandez, Aileen; Riggins, Rebecca B.

    2016-01-01

    Estrogen-related receptors (ERRs) are founding members of the orphan nuclear receptor (ONR) subgroup of the nuclear receptor superfamily. Twenty-seven years of study have yet to identify cognate ligands for the ERRs, though they have firmly placed ERRα and ERRγ at the intersection of cellular metabolism and oncogenesis. The pace of discovery for novel functions of ERRβ, however, has until recently been somewhat slower than that of its family members. ERRβ has also been largely ignored in summaries and perspectives of the ONR literature. Here, we provide an overview of established and emerging knowledge of ERRβ in mouse, man, and other species, highlighting unique aspects of ERRβ biology that set it apart from the other two estrogen-related receptors, with a focus on the impact of alternative splicing on the structure and function of this receptor. PMID:27507929

  3. Effects of CYP7B1-mediated catalysis on estrogen receptor activation.

    PubMed

    Pettersson, Hanna; Lundqvist, Johan; Norlin, Maria

    2010-09-01

    Most of the many biological effects of estrogens are mediated via the estrogen receptors ERalpha and beta. The current study examines the role of CYP7B1-mediated catalysis for activation of ER. Several reports suggest that CYP7B1 may be important for hormonal action but previously published studies are contradictory concerning the manner in which CYP7B1 affects ERbeta-mediated response. In the current study, we examined effects of several CYP7B1-related steroids on ER activation, using an estrogen response element (ERE) reporter system. Our studies showed significant stimulation of ER by 5-androstene-3beta,17beta-diol (Aene-diol) and 5alpha-androstane-3beta,17beta-diol (3beta-Adiol). In contrast, the CYP7B1-formed metabolites from these steroids did not activate the receptor, indicating that CYP7B1-mediated metabolism abolishes the ER-stimulating effect of these compounds. The mRNA level of HEM45, a gene known to be stimulated by estrogens, was strongly up-regulated by Aene-diol but not by its CYP7B1-formed metabolite, further supporting this concept. We did not observe stimulation by dehydroepiandrosterone (DHEA) or 7alpha-hydroxy-DHEA, previously suggested to affect ERbeta-mediated response. As part of these studies we examined metabolism of Aene-diol in pig liver which is high in CYP7B1 content. These experiments indicate that CYP7B1-mediated metabolism of Aene-diol is of a similar rate as the metabolism of the well-known CYP7B1 substrates DHEA and 3beta-Adiol. CYP7B1-mediated metabolism of 3beta-Adiol has been proposed to influence ERbeta-mediated growth suppression. Our results indicate that Aene-diol also might be important for ER-related pathways. Our data indicate that low concentrations of Aene-diol can trigger ER-mediated response equally well for both ERalpha and beta and that CYP7B1-mediated conversion of Aene-diol into a 7alpha-hydroxymetabolite will result in loss of action.

  4. RIME proteomics of estrogen and progesterone receptors in breast cancer

    PubMed Central

    D’Santos, Clive; Taylor, Christopher; Carroll, Jason S.; Mohammed, Hisham

    2015-01-01

    Nuclear receptors play an important role in transcriptional regulation of diverse cellular processes and is also relevant in diseases such as cancer. In breast cancer, the nuclear receptorsestrogen receptor (ER) and progesterone receptor (PR) are classical markers of the disease and are used to classify breast cancer subtypes. Using a recently developed affinity purification MS technique (RIME) [1], we investigate the protein interactors of ER and PR in breast cancer cell lines upon stimulation by the ligands – estrogen and progesterone. The data is deposited at proteomeXchange (PXD002104) and is part of a publication [2] that explains the link between the two nuclear receptors and potential consequences of this in breast cancer. In this manuscript, we describe the methodology used and provide details on experimental procedures, analysis methods and analysis of raw data. The purpose of this article is to enable reproducibility of the data and provide technical recommendations on performing RIME in hormonal contexts. PMID:26543891

  5. Estrogen receptor-alpha mediates estrogen facilitation of baroreflex heart rate responses in conscious mice.

    PubMed

    Pamidimukkala, Jaya; Xue, Baojian; Newton, Leslie G; Lubahn, Dennis B; Hay, Meredith

    2005-03-01

    Estrogen facilitates baroreflex heart rate responses evoked by intravenous infusion of ANG II and phenylephrine (PE) in ovariectomized female mice. The present study aims to identify the estrogen receptor subtype involved in mediating these effects of estrogen. Baroreflex responses to PE, ANG II, and sodium nitroprusside (SNP) were tested in intact and ovariectomized estrogen receptor-alpha knockout (ERalphaKO) with (OvxE+) or without (OvxE-) estrogen replacement. Wild-type (WT) females homozygous for the ERalpha(+/+) were used as controls. Basal mean arterial pressures (MAP) and heart rates were comparable in all the groups except the ERalphaKO-OvxE+ mice. This group had significantly smaller resting MAP, suggesting an effect of estrogen on resting vascular tone possibly mediated by the ERbeta subtype. Unlike the WT females, estrogen did not facilitate baroreflex heart rate responses to either PE or ANG II in the ERalphaKO-OvxE+ mice. The slope of the line relating baroreflex heart rate decreases with increases in MAP evoked by PE was comparable in ERalphaKO-OvxE- (-6.97 +/- 1.4 beats.min(-1).mmHg(-1)) and ERalphaKO-OvxE+ (-6.18 +/- 1.3) mice. Likewise, the slope of the baroreflex bradycardic responses to ANG II was similar in ERalphaKO-OvxE- (-3.87 +/- 0.5) and ERalphaKO-OvxE+(-2.60 +/- 0.5) females. Data suggest that estrogen facilitation of baroreflex responses to PE and ANG II is predominantly mediated by ERalpha subtype. A second important observation in the present study is that the slope of ANG II-induced baroreflex bradycardia is significantly blunted compared with PE in the intact as well as the ERalphaKO-OvxE+ females. We have previously reported that this ANG II-mediated blunting of cardiac baroreflexes is observed only in WT males and not in ovariectomized WT females independent of their estrogen replacement status. The present data suggest that in females lacking ERalpha, ANG II causes blunting of cardiac baroreflexes similar to males and may be

  6. Sex Hormones and Cardiometabolic Health: Role of Estrogen and Estrogen Receptors.

    PubMed

    Clegg, Deborah; Hevener, Andrea L; Moreau, Kerrie L; Morselli, Eugenia; Criollo, Alfredo; Van Pelt, Rachael E; Vieira-Potter, Victoria J

    2017-02-17

    With increased life expectancy, women will spend over three decades of life post-menopause. The menopausal transition increases susceptibility to metabolic diseases such as obesity, diabetes, cardiovascular disease, and cancer. Thus, it is more important than ever to develop effective hormonal treatment strategies to protect aging women. Understanding the role of estrogens, and their biological actions mediated by estrogen receptors (ERs), in the regulation of cardiometabolic health is of paramount importance to discover novel targeted therapeutics. In this brief review, we provide a detailed overview of the literature, from basic science findings to human clinical trial evidence, supporting a protective role of estrogens and their receptors, specifically ERα, in maintenance of cardiometabolic health. In so doing, we provide a concise mechanistic discussion of some of the major tissue-specific roles of estrogens signaling through ERα. Taken together, evidence suggests that targeted, perhaps receptor-specific, hormonal therapies can and should be used to optimize the health of women as they transition through menopause, while reducing the undesired complications that have limited the efficacy and use of traditional hormone replacement interventions.

  7. Estrogen Receptor Mutants/Variants in Human Breast Cancer.

    DTIC Science & Technology

    1997-12-01

    Recherche Louis- Charles Simard, Montreal, Canada. Four nor- mal human breast tissues from reduction mammoplasties of pre- menopausal women were obtained...to hormone resistance. Cancer Res 1990; 50: 6208-17. 22. Karnik PS, Kulkarni S, Lui XP, Budd GT, Bukowski RM. Estrogen receptor mutations in

  8. Estrogen Receptor Polymorphisms and the Vascular Effects of Hormone Therapy

    PubMed Central

    Rossouw, Jacques; Bray, Paul; Liu, Jingmin; Kooperberg, Charles; Hsia, Judith; Lewis, Cora; Cushman, Mary; Bonds, Denise; Hendrix, Susan; Papanicolaou, George; Howard, Tim; Herrington, David

    2010-01-01

    Objective To test whether estrogen receptor polymorphisms modify the effects of postmenopausal hormone therapy on biomarkers and on risk of coronary heart disease events, stroke, or venous thrombo-embolism. Methods and Results The design was a nested case-control study in the Women’s Health Initiative trials of postmenopausal hormone therapy. The study included all cases in the first 4 years: coronary heart disease, 359; stroke, 248; venous thrombo-embolism, 217). Six estrogen receptor-αand one estrogen receptor-β polymorphisms were genotyped; 8 biomarkers known to be affected by hormone therapy were measured at baseline and one year after randomization. The polymorphisms were not associated with risk of vascular events, and did not modify the increased risks of coronary heart disease, stroke, or venous thrombo-embolism due to hormone therapy. However, a reduced response of plasmin-antiplasmin (PAP) to hormone therapy was noted for ESR1 IVS1-354 (interaction P<0.0001, corrected for multiple comparisons P=0.014) and ESR1 IVS1-1415 (interaction P<0.0001, corrected P= 0.014). Conclusions Estrogen receptor polymorphisms reduce the effect of postmenopausal hormone therapy on PAP, a marker of coagulation and fibrinolysis. However screening for ER polymorphisms to identify women at less risk of adverse cardiovascular outcomes is not likely to be useful for making HT treatment decisions. PMID:21106950

  9. Pregnancy and estrogen receptor β expression in a large congenital nevus

    PubMed Central

    Nading, Mary Alice; Nanney, Lillian B.; Ellis, Darrel L.

    2013-01-01

    Introduction Large congenital nevi carry a slightly increased risk for the development of melanoma. Pregnancy poses an additional challenge in monitoring these patients as little is known regarding the effects of increased estrogen levels on congenital nevi. Observation A young woman was observed to have clinical lightening of her garment nevus and satellite nevi during two sequential pregnancies. Post-partum, the patient experienced darkening and re-pigmentation within her large garment nevus, with continued lightening of nearby satellite lesions. In addition to photographic documentation of these changes, biopsies taken during pregnant and non-pregnant periods were evaluated with immunohistochemistry for estrogen receptor beta (ERβ), the predominant estrogen receptor in nevi and melanomas. Biopsies taken during pregnancy showed a decrease in nuclear staining for ERβ when compared to biopsies taken following pregnancy. These changes in ERβ expression were not associated with histological atypia either during pregnancy or following delivery. Conclusion Congenital nevi may be unique in their response to altered estrogen levels. Given the slightly increased risk for the development of melanoma in giant congenital nevi and the dearth of information available regarding the effects of pregnancy on congenital nevi, this case illustrates the need for further study of these pigmented lesions. PMID:19528425

  10. Design and structure of stapled peptides binding to estrogen receptors.

    PubMed

    Phillips, Chris; Roberts, Lee R; Schade, Markus; Bazin, Richard; Bent, Andrew; Davies, Nichola L; Moore, Rob; Pannifer, Andrew D; Pickford, Andrew R; Prior, Stephen H; Read, Christopher M; Scott, Andrew; Brown, David G; Xu, Bin; Irving, Stephen L

    2011-06-29

    Synthetic peptides that specifically bind nuclear hormone receptors offer an alternative approach to small molecules for the modulation of receptor signaling and subsequent gene expression. Here we describe the design of a series of novel stapled peptides that bind the coactivator peptide site of estrogen receptors. Using a number of biophysical techniques, including crystal structure analysis of receptor-stapled peptide complexes, we describe in detail the molecular interactions and demonstrate that all-hydrocarbon staples modulate molecular recognition events. The findings have implications for the design of stapled peptides in general.

  11. Interplay between estrogen response element sequence and ligands controls in vivo binding of estrogen receptor to regulated genes.

    PubMed

    Krieg, Adam J; Krieg, Sacha A; Ahn, Bonnie S; Shapiro, David J

    2004-02-06

    To examine the role of the estrogen response element (ERE) sequence in binding of liganded estrogen receptor (ER) to promoters, we analyzed in vivo interaction of liganded ER with the imperfect ERE in the pS2 gene and the composite estrogen-responsive unit (ERU) in the proteinase inhibitor 9 (PI-9) gene. In transient transfections of ER-positive HepG2-ER7 cells, PI-9 was strongly induced by estrogen, moxestrol (MOX), and 4-hydroxytamoxifen (OHT). PI-9 was not induced by raloxifene or ICI 182,780. Quantitative reverse transcriptase-PCR showed that moxestrol strongly induced cellular PI-9 and pS2 mRNAs, whereas OHT moderately induced PI-9 mRNA and weakly induced pS2 mRNA. Chromatin immunoprecipitation experiments demonstrated strong and similar association of 17beta-estradiol-hERalpha and MOX-hERalpha with the PI-9 ERU and with the pS2 ERE. Binding of MOX-hERalpha to the PI-9 ERU and the pS2 ERE was rapid and continuous. Although MOX-hERalpha bound strongly to the PI-9 ERU and less well to the pS2 ERE in chromatin immunoprecipitation, gel shift assays showed that estrogen-hERalpha binds with higher affinity to the deproteinized pS2 ERE than to the PI-9 ERU. Across a broad range of OHT concentrations, OHT-hERalpha associated strongly with the pS2 ERE and weakly with the PI-9 ERU. ICI-hERalpha bound poorly to the PI-9 ERU and effectively to the pS2 ERE. Raloxifene-hERalpha and MOX-hERalpha exhibited similar binding to the PI-9 ERU and the pS2 ERE. These studies demonstrate that ER ligand and ERE sequence work together to regulate in vivo binding of ER to estrogen-responsive promoters.

  12. Estrogen Accelerates Cell Proliferation through Estrogen Receptor α during Rat Liver Regeneration after Partial Hepatectomy

    PubMed Central

    Batmunkh, Baatarsuren; Choijookhuu, Narantsog; Srisowanna, Naparee; Byambatsogt, Uugantsetseg; Synn Oo, Phyu; Noor Ali, Mohmand; Yamaguchi, Yuya; Hishikawa, Yoshitaka

    2017-01-01

    Although estrogen is implicated in the regulation of cell growth and differentiation in many organs, the exact mechanism for liver regeneration is not completely understood. We investigated the effect of estrogen on liver regeneration in male and female Wistar rats after 70% partial hepatectomy (PHx) and performed immunohistochemistry, western blotting and Southwestern histochemistry. 17β-estradiol (E2) and ICI 182,780 were injected into male rats on the day before PHx. The proliferating cell nuclear antigen (PCNA) labeling index reached a maximum at 48 hr after PHx in males, and at 36 hr in females and E2-treated male rats. Estrogen receptor α (ERα) was expressed in zones 1 and 2 in male rats, but was found in all zones in female rats. Interestingly, ERα was not detected at 6–12 hr after PHx but was found at 24–168 hr in male rats. However, ERα expression was found at all sampling time-points in female and E2-treated male rats. The activity of estrogen responsive element binding proteins was detected from 12 hr after PHx in male rats but was found from 6 hr in female and E2-treated male rats. ERα was co-expressed with PCNA during liver regeneration. These results indicate that estrogen may play an important role in liver regeneration through ERα. PMID:28386149

  13. A novel carborane analog, BE360, with a carbon-containing polyhedral boron-cluster is a new selective estrogen receptor modulator for bone

    SciTech Connect

    Hirata, Michiko; Inada, Masaki; Matsumoto, Chiho; Takita, Morichika; Ogawa, Takumi; Endo, Yasuyuki; Miyaura, Chisato

    2009-03-06

    Carboranes are a class of carbon-containing polyhedral boron-cluster compounds with globular geometry and hydrophobic surface that interact with hormone receptors. Estrogen deficiency results in marked bone loss due to increased osteoclastic bone resorption in females, but estrogen replacement therapy is not generally used for postmenopausal osteoporosis due to the risk of uterine cancer. We synthesized a novel carborane compound BE360 to clarify its anti-osteoporosis activity. BE360 showed a high binding affinity to estrogen receptors (ER), ER{alpha} and ER{beta}. In ovariectomized (OVX) mice, femoral bone volume was markedly reduced and BE360 dose-dependently restored bone loss in OVX mice. However, BE360 did not exhibit any estrogenic activity in the uterus. BE360 also restored bone loss in orchidectomized mice without androgenic action in the sex organs. Therefore, BE360 is a novel selective estrogen receptor modulator (SERM) that may offer a new therapy option for osteoporosis.

  14. Estrogen receptor genes in gastropods: phylogenetic divergence and gene expression responses to a synthetic estrogen.

    PubMed

    Hultin, Cecilia L; Hallgren, Per; Hansson, Maria C

    2016-11-01

    Endocrine disrupting chemicals (EDCs) have the potential to affect development and reproduction in gastropods. However, one is today lacking basic understanding of the Molluscan endocrine system and one can therefore not fully explain these EDC-induced affects. Furthermore, only a few genes that potentially may be connected to the endocrine system have been sequenced in gastropods. An example is the estrogen receptor gene (er) that have been identified in a restricted number of freshwater and marine gastropods. Here, we have identified a new partial coding sequence of an estrogen receptor gene (er) in the European common heterobranch Radix balthica. The following phylogenetic analysis divided the ers of heterobranchs and ceanogastropods in two branches. Furthermore, exposure to the synthetic estrogen 17α-ethinylestradiol (EE2) showed that exposure could significantly affect er expression level in the heterobranch R. balthica. This paper is the first that phylogenetically compares gastropods' er, basal er expression profiles, and transcriptional estrogenic responses in gastropods from two different evolutionary groups.

  15. Activation of the G protein-coupled estrogen receptor, but not estrogen receptor α or β, rapidly enhances social learning.

    PubMed

    Ervin, Kelsy Sharice Jean; Mulvale, Erin; Gallagher, Nicola; Roussel, Véronique; Choleris, Elena

    2015-08-01

    Social learning is a highly adaptive process by which an animal acquires information from a conspecific. While estrogens are known to modulate learning and memory, much of this research focuses on individual learning. Estrogens have been shown to enhance social learning on a long-term time scale, likely via genomic mechanisms. Estrogens have also been shown to affect individual learning on a rapid time scale through cell-signaling cascades, rather than via genomic effects, suggesting they may also rapidly influence social learning. We therefore investigated the effects of 17β-estradiol and involvement of the estrogen receptors (ERs) using the ERα agonist propyl pyrazole triol, the ERβ agonist diarylpropionitrile, and the G protein-coupled ER 1 (GPER1) agonist G1 on the social transmission of food preferences (STFP) task, within a time scale that focused on the rapid effects of estrogens. General ER activation with 17β-estradiol resulted in a modest facilitation of social learning, with mice showing a preference up to 30min of testing. Specific activation of the GPER1 also rapidly enhanced social learning, with mice showing a socially learned preference up to 2h of testing. ERα activation instead shortened the expression of a socially learned food preference, while ERβ activation had little to no effects. Thus, rapid estrogenic modulation of social learning in the STFP may be the outcome of competing action at the three main receptors. Hence, estrogens' rapid effects on social learning likely depend on the specific ERs present in brain regions recruited during social learning.

  16. Estrogen receptors in the temporomandibular joint of the baboon (Papio cynocephalus): an autoradiographic study

    SciTech Connect

    Aufdemorte, T.B.; Van Sickels, J.E.; Dolwick, M.F.; Sheridan, P.J.; Holt, G.R.; Aragon, S.B.; Gates, G.A.

    1986-04-01

    Using an autoradiographic method, the temporomandibular joint (TMJ) complex of five aged female baboons was studied for the presence of receptors for estradiol-17 beta. The study was performed in an effort to learn more of the pathophysiology of this joint and in an attempt to provide a scientific basis to explain the reported preponderance of women who seek and undergo treatment for signs and symptoms referable to the TMJ. This experiment revealed that the TMJ complex contains numerous cells with receptors for estrogen, particularly the articular surface of the condyle, articular disk, and capsule. Muscles of mastication contained relatively fewer receptors. As a result, one may postulate a role for the sex steroid hormones in the maintenance, repair, and/or pathogenesis of the TMJ. Additional studies are necessary to fully determine the significance of hormone receptors in this site and any correlation between diseases of the TMJ and the endocrine status of affected patients.

  17. Binding and transactivation of the largemouth bass estrogen receptors by model compounds

    EPA Science Inventory

    Environmental estrogens (EEs) are chemicals in the environment that can elicit adverse effects on estrogen (E2) signaling by binding with the estrogen receptors (ERs). In largemouth bass (LMB), the physiological actions of E2 are primarily mediated via three receptors (ERα, ERßb ...

  18. Estrogen binding and estrogen receptor activity in the human prostate: a preliminary report.

    PubMed

    Fondo, E Y; Menendez-Botet, C J; Schwartz, M K; Whitmore, W F

    1981-03-01

    Assay of estrogen receptor activity in prostates from patients who ranged in age from 22 to 78 years and had not received any previous hormonal therapy was carried out by incubation of cytosols with (3)H-estradiol in the presence and absence of excess, nonradioactive estradiol. Hyperplastic prostatic tissues were used in the study. The kinetics of each reaction were studied and analysis of the data revealed 3.4 to 35.7 femtomoles of receptor protein per mg of cytosol protein; the dissociation constants obtained from a Scatchard plot ranged from 1.1 × 10(-10) to 1.2 × 10(-8)M.The small number of patients prevents realistic quantitative assessment of the apparent estrogen binding activity demonstrated in these preliminary studies, but the qualitative identification of such activity provides possible grounds for further insight into the hormonal mechanisms in the pathophysiology of prostatic diseases and of their responses to endocrine therapy.

  19. [New method for the determination of estrogen and progesterone receptors in human breast cell lines].

    PubMed

    Olea, N; Devleeschower, N; Leclercq, G

    1985-12-01

    A method for the determination of estrogen and progesterone receptor levels in human mammary cell lines (MCF-7, Cama-1, ZR-75-1, Evsa-T and HBL-100) is described. Cells cultured as monolayers were incubated with the tritiated steroids, [3H]-17 beta-Estradiol or [3H] ORG-2058. Binding of steroids to receptors was a function of cellular uptake. Incubation periods of 50 min were sufficient to attain maximum intracellular incorporation. The binding of 17 beta-E2 and ORG-2058 to MCF-7 cells, a phenomenon which is saturable at low concentrations for the radioactive ligand, is a linear function of the number of cells assayed (Interval: 2.5 X 10(4) to 1.5 X 10(6) cells per well). Binding data and their Scatchard plot allowed for the calculation of affinity and capacity values. Thus, for ER, Kd = 2.0 +/- 0.5 X 10(-10) M and n = 3.76 +/- 0.91 Fmol/microgram DNA, and for PgR Kd = 2.0 +/- 0.2 X 10(-10) M and n = 14.02 +/- 2.30 Fmol/microgram DNA (Mean +/- SD). Binding specificity of 17 beta-Estradiol and ORG-2058 to MCF-7 cells was analysed by means of study on the inhibitory effect of increasing concentrations of unlabelled competitors: 17 beta-Estradiol, ORG-2058, Estrone, DES, R-5020, Cortisol, Androsterone and Testosterone. Only pharmacological doses of some of the mentioned molecules produce displacement of the hormonereceptor binding. This phenomenon appears to be related to the affinity of these chemical compounds for the receptor macromolecules to which estrogens and progesterone bind.

  20. Rat uterine oxytocin receptor and estrogen receptor α and β mRNA levels are regulated by estrogen through multiple estrogen receptors.

    PubMed

    Murata, Takuya; Narita, Kazumi; Ichimaru, Toru

    2014-03-07

    Estrogen action is mediated through several types of receptors (ERs), such as ERα, ERβ and putative membrane ERs. Oxytocin receptor (OTR) and ER expression levels in the rat uterus are regulated by estrogen; however, which types of ERs are involved has not been elucidated. This study examined OTR, ERα and ERβ levels in ovariectomized rats treated with 17β-estradiol (E2), an ERα agonist (PPT), an ERβ agonist (DPN) or estren (Es). E2 and PPT increased OTR mRNA levels and decreased ERα and ERβ mRNA levels 3 and 6 h posttreatment. DPN decreased ERα and ERβ mRNA levels at 3 and 6 h, while OTR mRNA levels increased at 3 h and decreased at 6 h. OTR mRNA levels increased 3 h after the Es treatment and then declined until 6 h. ERα and ERβ mRNA levels decreased by 3 h and remained low until 6 h posttreatment with Es. The ER antagonist ICI182,780 (ICI) suppressed the increases in OTR mRNA levels induced 3 h after the Es treatment. However, ICI and tamoxifen (Tam) had no significant effect on ERα and ERβ mRNA levels in the Es-treated or vehicle-treated group. In intact rats, proestrus-associated increases in OTR mRNA levels were antagonized by both ICI and Tam. However, decreases in ERα and ERβ mRNA levels were not antagonized by Tam and ICI, respectively. Therefore, uterine OTR gene expression is upregulated by estrogen through the classical nuclear (or non-nuclear) ERs, ERα and ERβ, while the levels of these ERs are downregulated by estrogen through multiple pathways including Es-sensitive nonclassical ERs.

  1. Neonatal oxytocin alters subsequent estrogen receptor alpha protein expression and estrogen sensitivity in the female rat.

    PubMed

    Perry, Adam N; Paramadilok, Auratip; Cushing, Bruce S

    2009-12-14

    In most species, the effects of oxytocin (OT) on female reproductive behavior are dependent upon estrogen, which increases both OT and OT receptor expression. It is also becoming apparent that OT neurotransmission can influence estrogen signaling, especially during development, as neonatal OT manipulations in prairie voles alter ERalpha expression and estrogen-dependent behaviors. We tested the hypothesis that OT developmentally programs ERalpha expression and estrogen sensitivity in female Sprague-Dawley rats, a species previously used to establish the estrogen-dependence of OT signaling in adulthood. OT treatment for the first postnatal week significantly increased ERalpha-immunoreactivity in the ventromedial nucleus of the hypothalamus (VMH), but not in the medial preoptic area (MPOA). Conversely, neonatal OT antagonist (OTA) treatment significantly reduced ERalpha-immunoreactivity in the MPOA, but not in the VMH. Both treatments increased OT-immunoreactivity in the paraventricular nucleus of the hypothalamus (PVN) and reduced estrogen sensitivity, indicated by reduced sexual receptivity following chronic estradiol benzoate (EB) administration. Behavioral deficits in OTA-treated females were apparent during both paced and non-paced tests with 0.5 microg EB (but not 5.0 or 10.0 microg EB), whereas deficits in OT-treated females were only observed during the initial paced test with 0.5 and 5.0 microg EB (but not 10.0 microg EB). The current results demonstrate that OT can positively regulate ERalpha expression within the MPOA and VMH during development; however, endogenous OT selectively programs ERalpha expression within the MPOA. Thus, exogenous OT or OTA exposure during development may have long-term consequences on behavior through stable changes in ERalpha and OT expression.

  2. Aryl hydrocarbon receptor-independent activation of estrogen receptor-dependent transcription by 3-methycholanthrene

    SciTech Connect

    Shipley, Jonathan M.; Waxman, David J. . E-mail: djw@bu.edu

    2006-06-01

    Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that stimulates transcription directed by xenobiotic response elements upstream of target genes. Recently, AhR ligands were reported to induce formation of an AhR-estrogen receptor (ER) complex, which can bind to estrogen response elements (EREs) and stimulate transcription of ER target genes. Presently, we investigate the effect of the AhR ligands 3-methylcholanthrene (3MC), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 3,3',4,4',5-pentachlorobiphenyl (BZ126) on ERE-regulated luciferase reporter activity and endogenous ER target gene expression. In MCF-7 human breast cancer cells, 3MC induced transcription of ER reporter genes containing native promoter sequences of the ER-responsive genes complement 3 and pS2 and heterologous promoters regulated by isolated EREs. Dose-response studies revealed that the concentration of 3MC required to half-maximally activate transcription (EC{sub 5}) was >100-fold higher for an ER reporter (27-57 {mu}M) than for an AhR reporter (86-250 nM) in both MCF-7 cells and in human endometrial cancer Ishikawa cells. 3MC also stimulated expression of the endogenous ER target genes amphiregulin, cathepsin D and progesterone receptor, albeit to a much lower extent than was achieved following stimulation with 17{beta}-estradiol. In Ishikawa cells, 3MC, but not BZ126 or TCDD, stimulated ER{alpha}-dependent reporter activity but did not induce expression of endogenous ER target genes. Finally, studies carried out in the AhR-positive rat hepatoma cell line 5L and the AhR-deficient variant BP8 demonstrated that ER reporter activity could be induced by 3MC in a manner that was independent of AhR and thus distinct from the AhR-ER 'hijacking' mechanism described recently. 3MC may thus elicit estrogenic activity by multiple mechanisms.

  3. INDUCTION OF MAMMARY GLAND DEVELOPMENT IN ESTROGEN RECEPTOR-ALPHA KNOCKOUT MICE

    EPA Science Inventory

    Mammary glands from the estrogen receptor knockout ( ERKO) mouse do not undergo ductal morphogenesis or alveolar development. Disrupted Er signaling may result in reduced estrogen-responsive gene products in the mammary gland or reduced mammotropic hormones that contribute t...

  4. Function of G-Protein-Coupled Estrogen Receptor-1 in Reproductive System Tumors

    PubMed Central

    Qian, Hongyan; Xuan, Jingxiu; Liu, Yuan; Shi, Guixiu

    2016-01-01

    The G-protein-coupled estrogen receptor-1 (GPER-1), also known as GPR30, is a novel estrogen receptor mediating estrogen receptor signaling in multiple cell types. The progress of estrogen-related cancer is promoted by GPER-1 activation through mitogen-activated protein kinases (MAPK), phosphoinositide 3-kinase (PI3K), and phospholipase C (PLC) signaling pathways. However, this promoting effect of GPER-1 is nonclassic estrogen receptor (ER) dependent manner. In addition, clinical evidences revealed that GPER-1 is associated with estrogen resistance in estrogen-related cancer patients. These give a hint that GPER-1 may be a novel therapeutic target for the estrogen-related cancers. However, preclinical studies also found that GPER-1 activation of its special agonist G-1 inhibits cancer cell proliferation. This review aims to summarize the characteristics and complex functions of GPER-1 in cancers. PMID:27314054

  5. COMPARISON OF FATHEAD MINNOW AND HUMAN ESTROGEN RECEPTOR BINDING TO ENDOCRINE DISRUPTING COMPOUNDS

    EPA Science Inventory

    Environmental estrogens have the potential to disrupt endocrine function in a myriad of species. However, in vitro assays designed to detect and characterize endocrine disrupting chemicals (EDCs) typically utilize mammalian estrogen receptors. Our overall objective is to charac...

  6. Selectivity of natural, synthetic and environmental estrogens for zebrafish estrogen receptors

    SciTech Connect

    Pinto, Caroline; Grimaldi, Marina; Boulahtouf, Abdelhay; Pakdel, Farzad; Brion, François; Aït-Aïssa, Sélim; Cavaillès, Vincent; Bourguet, William; Gustafsson, Jan-Ake; and others

    2014-10-01

    Zebrafish, Danio rerio, is increasingly used as an animal model to study the effects of pharmaceuticals and environmental estrogens. As most of these estrogens have only been tested on human estrogen receptors (ERs), it is necessary to measure their effects on zebrafish ERs. In humans there are two distinct nuclear ERs (hERα and hERβ), whereas the zebrafish genome encodes three ERs, zfERα and two zfERβs (zfERβ1 and zfERβ2). In this study, we established HeLa-based reporter cell lines stably expressing each of the three zfERs. We first reported that estrogens more efficiently activate the zfERs at 28 °C as compared to 37 °C, thus reflecting the physiological temperature of zebrafish in wildlife. We then showed significant differences in the ability of agonist and antagonist estrogens to modulate activation of the three zfER isotypes in comparison to hERs. Environmental compounds (bisphenol A, alkylphenols, mycoestrogens) which are hER panagonists and hERβ selective agonists displayed greater potency for zfERα as compared to zfERβs. Among hERα selective synthetic agonists, PPT did not activate zfERα while 16α-LE2 was the most zfERα selective compound. Altogether, these results confirm that all hER ligands control in a similar manner the transcriptional activity of zfERs although significant differences in selectivity were observed among subtypes. The zfER subtype selective ligands that we identified thus represent new valuable tools to dissect the physiological roles of the different zfERs. Finally, our work also points out that care has to be taken in transposing the results obtained using the zebrafish as a model for human physiopathology. - Highlights: • Zebrafish is increasingly used to study the effects of estrogens. • We assessed the activity of pharmaceutical and environmental estrogens on zfERs. • Environmental estrogens displayed greater potency for zfERα compared to zfERβs. • hERβ selective agonists displayed greater potency for zf

  7. Molecular cloning, expression, and regulation of estrogen receptors in pigeon oviduct epithelial cells.

    PubMed

    Zhang, H; Chen, F; Li, G L; Ding, Y Y; Tao, Z R; Li, J J; Zhong, S L; Lu, L Z

    2014-03-17

    Estrogen regulates reproductive behavior and drives the proliferation and differentiation of several cell types. These physiological functions of estrogen are mediated by estrogen receptors (ERs), and each ER isoform plays a distinct role. To clarify the molecular mechanism of estrogen action and to evaluate the effect of ERs on the secretion of ovalbumin (OVA) in pigeon oviduct epithelial cells (POECs), we determined the complete coding sequences encoding ER alpha (ERα) and ER beta (ERβ) in pigeons. The abundance of pigeon ERα and ERβ mRNA was detected using quantitative polymerase chain reaction. These results revealed that pigeon ERα is highly expressed in the oviduct, while pigeon ERb is highly expressed in the ovary and kidney. We hypothesize that ERα mRNA predominates over that of ERβ in the oviduct. The expression of ERα can be down-regulated by 17β-estradiol, and the knockdown of ERα promoted OVA mRNA expression in cultured POECs, indicating that ERα may play an important role in OVA secretion.

  8. Estrogen receptor-mediated neuroprotection: The role of the Alzheimer’s disease-related gene seladin-1

    PubMed Central

    Peri, Alessandro; Serio, Mario

    2008-01-01

    Experimental evidence supports a protective role of estrogen in the brain. According to the fact that Alzheimer’s disease (AD) is more common in postmenopausal women, estrogen treatment has been proposed. However, there is no general consensus on the beneficial effect of estrogen or selective estrogen receptor modulators in preventing or treating AD. It has to be said that several factors may markedly affect the efficacy of the treatment. A few years ago, the seladin-1 gene (for selective Alzheimer’s disease indicator-1) has been isolated and found to be down-regulated in brain regions affected by AD. Seladin-1 has been found to be identical to the gene encoding the enzyme 3-beta-hydroxysterol delta-24-reductase, involved in the cholesterol biosynthetic pathway, which confers protection against β-amyloid-mediated toxicity and from oxidative stress, and is an effective inhibitor of caspase-3 activity, a key mediator of apoptosis. Interestingly, we found earlier that the expression of this gene is up-regulated by estrogen. Furthermore, our very recent data support the hypothesis that seladin-1 is a mediator of the neuroprotective effects of estrogen. This review will summarize the current knowledge regarding the neuroprotective effects of seladin-1 and the relationship between this protein and estrogen. PMID:19043524

  9. Proliferation of Estrogen Receptor alpha Positive Mammary Epithelial Cells is Restrained by TGFbeta1 in Adult Mice

    SciTech Connect

    Ewan, Kenneth B.R.; Oketch-Rabah, Hellen A.; Ravani, Shraddha A.; Shyamala, G.; Moses, Harold L.; Barcellos-Hoff, Mary Helen

    2005-03-03

    Transforming growth factor {beta}1 (TGF{beta}1) is a potent inhibitor of mammary epithelial proliferation. In human breast, estrogen receptor {alpha} (ER{alpha}) cells rarely co-localize with markers of proliferation, but their increased frequency correlates with breast cancer risk. To determine whether TGF{beta}1 is necessary for the quiescence of ER{alpha}-positive population, we examined mouse mammary epithelial gland at estrus. Approximately 35% of cells showed TGF{beta}1 activation, which co-localized with nuclear receptor-phosphorylated Smad 2/3, indicating that TGF{beta} signaling is autocrine. Furthermore, nuclear Smad co-localized with nuclear ER{alpha}. To test whether TGF{beta} was functional, we examined genetically engineered mice with different levels of TGF{beta}1. ER{alpha} co-localization with markers of proliferation (i.e. Ki-67 or BrdU) at estrus was significantly increased in the mammary glands of Tgf{beta}1 C57/bl/129SV heterozygote mice. This relationship was maintained following pregnancy, but was absent at puberty. Conversely, mammary epithelial expression of constitutively active TGF{beta}1 via the MMTV promoter suppressed proliferation of ER{alpha} positive cells. Thus, TGF{beta}1 activation functionally restrains ER{alpha} positive cells from proliferating in adult mammary gland. Accordingly, we propose that TGF{beta}1 dysregulation may promote proliferation of ER{alpha} positive cells associated with breast cancer risk in humans.

  10. Expression of estrogen and progesterone receptors in astrocytomas: a literature review

    PubMed Central

    Tavares, Cléciton Braga; Gomes-Braga, Francisca das Chagas Sheyla Almeida; Costa-Silva, Danylo Rafhael; Escórcio-Dourado, Carla Solange; Borges, Umbelina Soares; Conde, Airton Mendes; da Conceição Barros-Oliveira, Maria; Sousa, Emerson Brandão; da Rocha Barros, Lorena; Martins, Luana Mota; Facina, Gil; da-Silva, Benedito Borges

    2016-01-01

    Gliomas are the most common type of primary central nervous system neoplasm. Astrocytomas are the most prevalent type of glioma and these tumors may be influenced by sex steroid hormones. A literature review for the presence of estrogen and progesterone receptors in astrocytomas was conducted in the PubMed database using the following MeSH terms: “estrogen receptor beta” OR “estrogen receptor alpha” OR “estrogen receptor antagonists” OR “progesterone receptors” OR “astrocytoma” OR “glioma” OR “glioblastoma”. Among the 111 articles identified, 13 studies met our inclusion criteria. The majority of reports showed the presence of estrogen and progesterone receptors in astrocytomas. Overall, higher tumor grades were associated with decreased estrogen receptor expression and increased progesterone receptor expression. PMID:27626480

  11. Channel catfish (Ictalurus punctatus) leukocytes express estrogen receptor isoforms ERα and ERβ2 and are functionally modulated by estrogens

    USGS Publications Warehouse

    Iwanowicz, Luke R.; Stafford, James L.; Patiño, Reynaldo; Bengten, Eva; Miller, Norman W.; Blazer, Vicki

    2014-01-01

    Estrogens are recognized as modulators of immune responses in mammals and teleosts. While it is known that the effects of estrogens are mediated via leukocyte-specific estrogen receptors (ERs) in humans and mice, leucocyte-specific estrogen receptor expression and the effects of estrogens on this cell population is less explored and poorly understood in teleosts. Here in, we verify that channel catfish (Ictalurus punctaus) leukocytes express ERα and ERβ2. Transcripts of these isoforms were detected in tissue-associated leukocyte populations by PCR, but ERβ2 was rarely detected in PBLs. Expression of these receptors was temporally regulated in PBLs following polyclonal activation by concanavalin A, lipopolysaccharide or alloantigen based on evaluation by quantitative and end-point PCR. Examination of long-term leukocyte cell lines demonstrated that these receptors are differentially expressed depending on leukocyte lineage and phenotype. Expression of ERs was also temporally dynamic in some leukocyte lineages and may reflect stage of cell maturity. Estrogens affect the responsiveness of channel catfish peripheral blood leukocytes (PBLs) to mitogens in vitro. Similarly, bactericidal activity and phorbol 12-myristate 13-acetate induced respiratory burst was modulated by 17β-estradiol. These actions were blocked by the pure ER antagonist ICI 182780 indicating that response is, in part, mediated via ERα. In summary, estrogen receptors are expressed in channel catfish leukocytes and participate in the regulation of the immune response. This is the first time leukocyte lineage expression has been reported in teleost cell lines.

  12. Cloning, expression and functional characterization of carp, Cyprinus carpio, estrogen receptors and their differential activations by estrogens.

    PubMed

    Katsu, Yoshinao; Lange, Anke; Miyagawa, Shinichi; Urushitani, Hiroshi; Tatarazako, Norishisa; Kawashima, Yukio; Tyler, Charles R; Iguchi, Taisen

    2013-01-01

    Sex-steroid hormones are essential for normal reproductive activity in both sexes. Estrogens are necessary for ovarian differentiation during a critical developmental stage in vertebrates and promote the growth and differentiation of the female reproductive system. Importantly, environmental estrogens can influence the reproductive system and have been shown to disrupt gametogenesis in males. To understand the molecular mechanisms of estrogen actions and to evaluate estrogen receptor ligand interactions in the carp, Cyprinus carpio, a species used widely for both field- and laboratory-based studies, we cloned all three carp estrogen receptors (ER; ERα, ERβ1 and ERβ2) and applied an estrogen-responsive (ERE)-luciferase reporter assay system to characterize the interactions of these receptors with steroidal and synthetic estrogens. DNA fragments encoding all three ERs in carp, ERα, ERβ1 and ERβ2, were obtained from the ovary using degenerate primer sets and PCR techniques, and full-length carp ER (cER) cDNAs were then obtained using RACE (rapid amplification of the cDNA end) techniques. Amino acid sequences of cERs showed overall homology of 46% (α vs β1), 49% (α vs β2) and 53% (β1 vs β2). In the transient transfection ERE-luciferase reporter assay system (using mammalian cells) the cER proteins displayed estrogen-dependent activation of transcription and cERβ2 showed a higher sensitivity to the natural steroid oestrogen, 17β-estradiol, than cERα. The assay system developed is a powerful assay for toxicology and provides a tool for future studies examining the receptor-environmental chemical interactions and estrogen-disrupting mechanisms in carp. The data presented also expand our knowledge of estrogen receptor evolution.

  13. Aromatase, estrogen receptors and brain development in fish and amphibians.

    PubMed

    Coumailleau, Pascal; Pellegrini, Elisabeth; Adrio, Fátima; Diotel, Nicolas; Cano-Nicolau, Joel; Nasri, Ahmed; Vaillant, Colette; Kah, Olivier

    2015-02-01

    Estrogens affect brain development of vertebrates, not only by impacting activity and morphology of existing circuits, but also by modulating embryonic and adult neurogenesis. The issue is complex as estrogens can not only originate from peripheral tissues, but also be locally produced within the brain itself due to local aromatization of androgens. In this respect, teleost fishes are quite unique because aromatase is expressed exclusively in radial glial cells, which represent pluripotent cells in the brain of all vertebrates. Expression of aromatase in the brain of fish is also strongly stimulated by estrogens and some androgens. This creates a very intriguing positive auto-regulatory loop leading to dramatic aromatase expression in sexually mature fish with elevated levels of circulating steroids. Looking at the effects of estrogens or anti-estrogens in the brain of adult zebrafish showed that estrogens inhibit rather than stimulate cell proliferation and newborn cell migration. The functional meaning of these observations is still unclear, but these data suggest that the brain of fish is experiencing constant remodeling under the influence of circulating steroids and brain-derived neurosteroids, possibly permitting a diversification of sexual strategies, notably hermaphroditism. Recent data in frogs indicate that aromatase expression is limited to neurons and do not concern radial glial cells. Thus, until now, there is no other example of vertebrates in which radial progenitors express aromatase. This raises the question of when and why these new features were gained and what are their adaptive benefits. This article is part of a Special Issue entitled: Nuclear receptors in animal development.

  14. No substantial changes in estrogen receptor and estrogen-related receptor orthologue gene transcription in Marisa cornuarietis exposed to estrogenic chemicals☆☆☆

    PubMed Central

    Bannister, Richard; Beresford, Nicola; Granger, David W.; Pounds, Nadine A.; Rand-Weaver, Mariann; White, Roger; Jobling, Susan; Routledge, Edwin J.

    2013-01-01

    Estrogen receptor orthologues in molluscs may be targets for endocrine disruptors, although mechanistic evidence is lacking. Molluscs are reported to be highly susceptible to effects caused by very low concentrations of environmental estrogens which, if substantiated, would have a major impact on the risk assessment of many chemicals. The present paper describes the most thorough evaluation to-date of the susceptibility of Marisa cornuarietis ER and ERR gene transcription to modulation by vertebrate estrogens in vivo and in vitro. We investigated the effects of estradiol-17β and 4-tert-Octylphenol exposure on in vivo estrogen receptor (ER) and estrogen-related receptor (ERR) gene transcription in the reproductive and neural tissues of the gastropod snail M. cornuarietis over a 12-week period. There was no significant effect (p > 0.05) of treatment on gene transcription levels between exposed and non-exposed snails. Absence of a direct interaction of estradiol-17β and 4-tert-Octylphenol with mollusc ER and ERR protein was also supported by in vitro studies in transfected HEK-293 cells. Additional in vitro studies with a selection of other potential ligands (including methyl-testosterone, 17α-ethinylestradiol, 4-hydroxytamoxifen, diethylstilbestrol, cyproterone acetate and ICI182780) showed no interaction when tested using this assay. In repeated in vitro tests, however, genistein (with mcER-like) and bisphenol-A (with mcERR) increased reporter gene expression at high concentrations only (>10−6 M for Gen and >10−5 M for BPA, respectively). Like vertebrate estrogen receptors, the mollusc ER protein bound to the consensus vertebrate estrogen-response element (ERE). Together, these data provide no substantial evidence that mcER-like and mcERR activation and transcript levels in tissues are modulated by the vertebrate estrogen estradiol-17β or 4-tert-Octylphenol in vivo, or that other ligands of vertebrate ERs and ERRs (with the possible exception of

  15. Multiple Estrogen Receptor Subtypes Influence Ingestive Behavior in Female Rodents

    PubMed Central

    Santollo, Jessica; Daniels, Derek

    2015-01-01

    Postmenopausal women are at an increased risk of obesity and cardiovascular-related diseases. This is attributable, at least in part, to loss of the ovarian hormone estradiol, which inhibits food and fluid intake in humans and laboratory animal models. Although the hypophagic and anti-dipsogenic effects of estradiol have been well documented for decades, the precise mechanisms underlying these effects are not fully understood. An obvious step toward addressing this open question is identifying which estrogen receptor subtypes are involved and what intracellular processes are involved. This question, however, is complicated not only by the variety of estrogen receptor subtypes that exist, but also because many subtypes have multiple locations of action (i.e. in the nucleus or in the plasma membrane). This review will highlight our current understanding of the roles specific estrogen receptor subtypes play in mediating estradiol’s anorexigenic and anti-dipsogenic effects along with highlighting the many open questions that remain. This review will also describe recent work being performed by our laboratory aimed at answering these open questions. PMID:26037634

  16. Splice isoform estrogen receptors as integral transmembrane proteins.

    PubMed

    Kim, Kyung Hee; Toomre, Derek; Bender, Jeffrey R

    2011-11-01

    In addition to enhancing or repressing transcription, steroid hormone receptors rapidly transduce kinase activation signals. On ligand engagement, an N-terminus-truncated splice isoform of estrogen receptor (ER) α, ER46, triggers membrane-initiated signals, resulting in endothelial nitric oxide synthase (eNOS) activation and endothelial NO production. The orientation of ER46 at the plasma membrane is incompletely defined. With the use of ecliptic pHluorin-fused ER46, total internal reflection fluorescence microscopy in live human endothelial cells illustrates that ER46 can topologically conform to a type I transmembrane protein structure. Mutation of isoleucine-386 at the center of ER46's transmembrane hydrophobic core prevents membrane spanning, obscures the N-terminal ectodomain, and effects a marked reduction in membrane-impermeant estrogen binding with diminished rapid eNOS activation and NO production, despite maintained genomic induction of an estrogen response element-luciferase reporter. Thus there exist pools of transmembrane steroid hormone receptors that are efficient signaling molecules and potential novel therapeutic targets.

  17. Multiple estrogen receptor subtypes influence ingestive behavior in female rodents.

    PubMed

    Santollo, Jessica; Daniels, Derek

    2015-12-01

    Postmenopausal women are at an increased risk of obesity and cardiovascular-related diseases. This is attributable, at least in part, to loss of the ovarian hormone estradiol, which inhibits food and fluid intake in humans and laboratory animal models. Although the hypophagic and anti-dipsogenic effects of estradiol have been well documented for decades, the precise mechanisms underlying these effects are not fully understood. An obvious step toward addressing this open question is identifying which estrogen receptor subtypes are involved and what intracellular processes are involved. This question, however, is complicated not only by the variety of estrogen receptor subtypes that exist, but also because many subtypes have multiple locations of action (i.e. in the nucleus or in the plasma membrane). This review will highlight our current understanding of the roles that specific estrogen receptor subtypes play in mediating estradiol's anorexigenic and anti-dipsogenic effects along with highlighting the many open questions that remain. This review will also describe recent work being performed by our laboratory aimed at answering these open questions.

  18. Selectivity of natural, synthetic and environmental estrogens for zebrafish estrogen receptors.

    PubMed

    Pinto, Caroline; Grimaldi, Marina; Boulahtouf, Abdelhay; Pakdel, Farzad; Brion, François; Aït-Aïssa, Sélim; Cavaillès, Vincent; Bourguet, William; Gustafsson, Jan-Ake; Bondesson, Maria; Balaguer, Patrick

    2014-10-01

    Zebrafish, Danio rerio, is increasingly used as an animal model to study the effects of pharmaceuticals and environmental estrogens. As most of these estrogens have only been tested on human estrogen receptors (ERs), it is necessary to measure their effects on zebrafish ERs. In humans there are two distinct nuclear ERs (hERα and hERβ), whereas the zebrafish genome encodes three ERs, zfERα and two zfERβs (zfERβ1 and zfERβ2). In this study, we established HeLa-based reporter cell lines stably expressing each of the three zfERs. We first reported that estrogens more efficiently activate the zfERs at 28°C as compared to 37°C, thus reflecting the physiological temperature of zebrafish in wildlife. We then showed significant differences in the ability of agonist and antagonist estrogens to modulate activation of the three zfER isotypes in comparison to hERs. Environmental compounds (bisphenol A, alkylphenols, mycoestrogens) which are hER panagonists and hERβ selective agonists displayed greater potency for zfERα as compared to zfERβs. Among hERα selective synthetic agonists, PPT did not activate zfERα while 16α-LE2 was the most zfERα selective compound. Altogether, these results confirm that all hER ligands control in a similar manner the transcriptional activity of zfERs although significant differences in selectivity were observed among subtypes. The zfER subtype selective ligands that we identified thus represent new valuable tools to dissect the physiological roles of the different zfERs. Finally, our work also points out that care has to be taken in transposing the results obtained using the zebrafish as a model for human physiopathology.

  19. Evolution of estrogen receptors in ray-finned fish and their comparative responses to estrogenic substances.

    PubMed

    Tohyama, Saki; Miyagawa, Shinichi; Lange, Anke; Ogino, Yukiko; Mizutani, Takeshi; Ihara, Masaru; Tanaka, Hiroaki; Tatarazako, Norihisa; Kobayashi, Tohru; Tyler, Charles R; Iguchi, Taisen

    2016-04-01

    In vertebrates, estrogens play fundamental roles in regulating reproductive activities through estrogen receptors (ESRs), and disruption of estrogen signaling is now of global concern for both wildlife and human health. To date, ESRs of only a limited number of species have been characterized. We investigated the functional diversity and molecular basis or ligand sensitivity of ESRs among ray-finned fish species (Actinopterygii), the most variable group within vertebrates. We cloned and characterized ESRs from several key species in the evolution of ray-finned fish including bichir (Polypteriformes, ESR1 and ESR2) at the basal lineage of ray-finned fish, and arowana (Osteoglossiformes, ESR1 and ESR2b) and eel (Anguilliformes, ESR1, ESR2a and ESR2b) both belonging to ancient early-branching lineages of teleosts, and suggest that ESR2a and ESR2b emerged through teleost-specific whole genome duplication, but an ESR1 paralogue has been lost in the early lineage of euteleost fish species. All cloned ESR isoforms showed similar responses to endogenous and synthetic steroidal estrogens, but they responded differently to non-steroidal estrogenic endocrine disrupting chemicals (EDCs) (e.g., ESR2a exhibits a weaker reporter activity compared with ESR2b). We show that variation in ligand sensitivity of ESRs can be attributed to phylogeny among species of different taxonomic groups in ray-finned fish. The molecular information provided contributes both to understanding of the comparative role of ESRs in the reproductive biology of fish and their comparative responses to EDCs.

  20. Estrogen has anti-amyloidogenic effects on Alzheimer's {beta}-amyloid fibrils in vitro

    SciTech Connect

    Morinaga, Akiyoshi; Hirohata, Mie; Ono, Kenjiro; Yamada, Masahito . E-mail: m-yamada@med.kanazawa-u.ac.jp

    2007-08-03

    Inhibition of the assembly of amyloid {beta}-peptide (A{beta}) as well as the destabilization of preformed {beta}-amyloid fibrils (fA{beta}) in the central nervous system could be valuable therapeutics of patients with Alzheimer's disease (AD). Epidemiological studies have indicated that estrogen therapy reduced the risk of developing AD in women. Here, we examined the effects of estrogen (estrone (E1), estradiol (E2), and estriol (E3)) and related sexual steroids (androstenedione (AND) and testosterone (TES)) on the polymerization, extension and destabilization of fA{beta}(1-42) and fA{beta}(1-40) at pH 7.5 at 37 {sup o}C in vitro, using fluorescence spectroscopic analysis with thioflavin T and electron microscopic studies. E1, E2, and E3 dose-dependently inhibited the formation, as well as destabilization of fA{beta}s. The overall anti-amyloidogenic activity of these molecules was in the order of: E3 > E2 = E1 >>AND = TES. Estrogen could be a potential therapeutic agent to prevent or delay AD progression.

  1. The role of estrogens and estrogen receptor signaling pathways in cancer and infertility: the case of schistosomes.

    PubMed

    Botelho, Mónica C; Alves, Helena; Barros, Alberto; Rinaldi, Gabriel; Brindley, Paul J; Sousa, Mário

    2015-06-01

    Schistosoma haematobium, a parasitic flatworm that infects more than 100 million people, mostly in the developing world, is the causative agent of urogenital schistosomiasis, and is associated with a high incidence of squamous cell carcinoma (SCC) of the bladder. Schistosomiasis haematobia also appears to negatively influence fertility, and is particularly associated with female infertility. Given that estrogens and estrogen receptors are key players in human reproduction, we speculate that schistosome estrogen-like molecules may contribute to infertility through hormonal imbalances. Here, we review recent findings on the role of estrogens and estrogen receptors on both carcinogenesis and infertility associated with urogenital schistosomiasis and discuss the basic hormonal mechanisms that might be common in cancer and infertility.

  2. [Cardiovascular effects of selective estrogen receptor modulators. Current perspectives].

    PubMed

    Simoncini, Tommaso; Mannella, Paolo; Genazzani, Andrea R

    2003-02-01

    The use of hormone replacement therapy (HRT) after the menopause for the prevention of the long-term complications of estrogen deprivation has recently been questioned after the publication of large clinical trials that failed to show benefits for postmenopausal women. Although these trials risk to dump the widespread opinion of the cardioprotective effects of long-term estrogen use, they have many pitfalls that prevent a direct clinical application of these negative results. Furthermore, the large amount of epidemiological and experimental evidence indicating estrogens as protective on the vascular system cannot be ignored, and efforts should be devoted to understand the reasons for the discrepancy of results of these recent large trials. In the meanwhile, different molecules should be studied in depth as for the actions on the cardiovascular system, and their specific mechanisms of actions should be elucidated. Selective estrogen receptor modulators (SERM) are a promising family of molecules and some of these compounds have positive effects on cardiovascular risk parameters as well as on vascular cells. Large trials are ongoing to study the impact of these substances on cardiovascular risk, and the near future should provide us with answers on the possible use of SERM as possible safer alternatives to HRT for the long-term prevention of cardiovascular disease in postmenopausal women.

  3. Nuclear estrogen receptor molecular heterogeneity in the mouse uterus

    SciTech Connect

    Golding, T.S.; Korach, K.S.

    1988-01-01

    Holomeric estrogen receptor (ER) prepared from ovariectomized mouse uteri displays heterogeneous electrophoretic mobility when analyzed by NaDodSO/sub 4//PAGE. ER derived from nuclei (ER/sub n/) appears as a closely spaced doublet having apparent molecular masses of 66.4 and 65 kDa, while ER from the cytosolic compartment (ER/sub c/) has a single band of 65 kDa. Both partially purified ER/sub c/ and the 8S form of unactivated ER/sub c/ show only the 65-kDa band. The appearance of the ER/sub n/ doublet is hormonally inducible, and the relative proportions of the two doublet bands are influenced by the type of hormone treatment, with weakly estrogenic compounds yielding the lower band as predominant while potent estrogens increase the proportion of the upper band. Steroid binding of the ER/sub n/ doublet was determined by (/sup 3/H)tamoxifen aziridine affinity labeling of both the 66.4- and the 65-kDa peptides; binding to the 65-kDa peptide was predominant. The ER/sub n/ doublet displays a time dependency after estrogen administration with maximal amounts occurring in a bimodal fashion at 1 and 8 hr.

  4. Molecular cloning and characterization of hagfish estrogen receptors.

    PubMed

    Nishimiya, Osamu; Katsu, Yoshinao; Inagawa, Hiroyuki; Hiramatsu, Naoshi; Todo, Takashi; Hara, Akihiko

    2017-01-01

    One or more distinct forms of the nuclear estrogen receptor (ER) have been isolated from many vertebrates to date. To better understand the molecular evolution of ERs, we cloned and characterized er cDNAs from the inshore hagfish, Eptatretus burgeri, a modern representative of the most primitive vertebrates, the agnathans. Two er cDNAs, er1 and er2, were isolated from the liver of a reproductive female hagfish. A phylogenetic analysis placed hagfish ER1 into a position prior to the divergence of vertebrate ERs. Conversely, hagfish ER2 was placed at the base of the vertebrate ERβ clade. The tissue distribution patterns of both ER subtype mRNAs appeared to be different, suggesting that each subtype has different physiological roles associated with estrogen actions. An estrogen responsive-luciferase reporter assay using mammalian HEK293 cells was used to functionally characterize these hagfish ERs. Both ER proteins displayed estrogen-dependent activation of transcription. These results clearly demonstrate that the hagfish has two functional ER subtypes.

  5. Colocalization of Estrogen Receptors with the Fluorescent Tamoxifen Derivative, FLTX1, Analyzed by Confocal Microscopy.

    PubMed

    Morales, Araceli; Marín, Raquel; Marrero-Alonso, Jorge; Boto, Alicia; Díaz, Mario

    2016-01-01

    Tamoxifen is a selective estrogen receptor modulator that competitively binds the ligand-binding domain of estrogen receptors. Binding of tamoxifen displaces its cognate ligand, 17β-estradiol, thereby hampering the activation of estrogen receptors. Cellular labeling of ER is typically carried out using specific antibodies which require permeabilization of cells, incubation with secondary antibodies, and are expensive and time consuming. In this article, we describe the usefulness of FLTX1, a novel fluorescent tamoxifen derivative, which allows the labeling of estrogen receptors in immunocytochemistry and immunohistochemistry studies, both under permeabilized and non-permeabilized conditions. Further, besides labeling canonical estrogen receptors, this novel fluorescent probe is also suitable for the identification of unconventional targets such membrane estrogen receptors as well as other noncanonical targets, some of which are likely responsible for the number of undesired side effects reported during long-term tamoxifen treatments.

  6. Estrogen and Progesterone hormone receptor expression in oral cavity cancer

    PubMed Central

    Biegner, Thorsten; Teriete, Peter; Hoefert, Sebastian; Krimmel, Michael; Munz, Adelheid; Reinert, Siegmar

    2016-01-01

    Background Recent studies have shown an increase in the incidence of oral squamous cell carcinoma (OSCC) in younger patients. The hypothesis that tumors could be hormonally induced during pregnancy or in young female patients without the well-known risk factors alcohol or tobacco abuse seems to be plausible. Material and Methods Estrogen Receptor alpha (ERα) and Progesterone Receptor (PR) expression were analyzed in normal oral mucosa (n=5), oral precursor lesions (simple hyperplasia, n=11; squamous intraepithelial neoplasia, SIN I-III, n=35), and OSCC specimen. OSCCs were stratified in a young female (n=7) study cohort and older patients (n=46). In the young female study cohort three patients (n=3/7) developed OSCC during or shortly after pregnancy. Breast cancer tissues were used as positive control for ERα and PR expression. Results ERα expression was found in four oral precursor lesions (squamous intraepithelial neoplasia, SIN I-III, n=4/35, 11%) and in five OSCC specimen (n=5/46, 11%). The five ERα positive OSCC samples were older male patients. All patients within the young female study cohort were negatively stained for both ERα and PR. Conclusions ER expression could be regarded as a seldom risk factor for OSCC. PR expression seems to be not relevant for the development of OSCC. Key words:Oral squamous cell carcinoma, estrogen receptor, progesterone receptor, hormone receptor. PMID:27475696

  7. In vitro estrogen receptor binding of PCBs: measured activity and detection of hydroxylated metabolites in a recombinant yeast assay.

    PubMed

    Layton, Alice C; Sanseverino, John; Gregory, Betsy W; Easter, James P; Sayler, Gary S; Schultz, T Wayne

    2002-05-01

    The estrogenic activities of 17beta-estradiol, biphenyl, chlorinated biphenyls, and Aroclor mixtures 1221, 1242, and 1248 were measured with a modified recombinant yeast estrogen assay (i.e., a Saccharomyces cerevisiae-based lac-Z (beta-galactosidase) reporter assay). Modifications of the assay included the use of glass vials instead of plastic microtiter plates and the addition of the medium and yeast before the test substrate. 14C-labeled compounds were used to follow improvements in the assay procedures. 14C-17beta-estradiol recovery from plastic microtiter plates and glass vials using the standard or the modified procedure was approximately 89%. However, 14C-4-CB (4-chlorobiphenyl) recovery was considerably less, ranging from 3% in plastic microtiter plates using the standard procedure to 26% in vials using the modified procedure. These results suggest that the toxicity of strongly hydrophobic chemicals may be underestimated. Using the modified yeast estrogen assay, full agonist activity was observed for 4-CB, 2,4,6-CB, and 2,5-CB while each of the Aroclor mixtures were only partial agonists. The equivalent EC50 values in ppm were in environmentally relevant concentrations for biphenyl (19 ppm), 4-CB (4.5 ppm), 2,5-CB (21 ppm), 2,4,6-CB (0.8 ppm), Aroclor 1221 (2.9 ppm), Aroclor 1242 (0.65 ppm), and Aroclor 1248 (2.3 ppm). Estrogen receptor binding for the individual PCB congeners was 25- to 650-fold less than the reported estrogen binding for the corresponding hydroxylated PCB metabolite. Gas chromatographic/mass spectrometric analysis of yeast extracts indicated that S. cerevisiae hydroxylated the individual PCB congeners in the ppb range. With the exception of biphenyl, the concentration of hydroxylated metabolites obtained from incubation of S. cerevisiae with PCB congeners was consistent with the concentration necessary to elicit a positive estrogen receptor-binding response. This work provides evidence that S. cerevisiae are capable of metabolic

  8. Hippocampal cytosolic estrogen receptors regulate fear generalization in females.

    PubMed

    Lynch, Joseph F; Winiecki, Patrick; Vanderhoof, Tyler; Riccio, David C; Jasnow, Aaron M

    2016-04-01

    Generalization of fear responses is a symptom of many anxiety disorders and we have previously demonstrated that female rats generalize fear to a neutral context at a faster rate compared to males. This effect is due in part, to activation of ER and modulation of memory retrieval mechanisms resulting in fear generalization. Given that the effects of estradiol on fear generalization required approximately 24h, our data suggested possible genomic actions on fear generalization. To determine whether these actions were due to cytosolic versus membrane bound receptors, female rats were given infusions of ICI 182,780, a cytosolic estrogen receptor antagonist, into the lateral ventricle or dorsal hippocampus simultaneously with estradiol treatment or with an ER agonist (DPN). Infusions of ICI into the lateral ventricle or the dorsal hippocampus blocked fear generalization induced by peripheral or central treatment with estradiol or DPN, suggesting that estradiol acts through cytosolic ERβ receptors. In further support of these findings, intracerebroventricular or intra-hippocampal infusions of bovine serum conjugated estradiol (E2-BSA), activating membrane-bound estrogen receptors only, did not induce fear generalization. Moreover, rats receiving intra-hippocampal infusions of the ERK/MAPK inhibitor, U0126, continued to display estradiol-induced generalization, again suggesting that membrane-bound estrogen receptors do not contribute to fear generalization. Overall, these data suggest that estradiol-induced enhancements in fear generalization are mediated through activation of cytosolic/nuclear ER within the dorsal hippocampus. This region seems to be an important locus for the effects of estradiol on fear generalization although additional neuroanatomical regions have yet to be identified.

  9. Hormone Binding to Recombinant Estrogen Receptors from Human, Alligator, Quail, Salamander, and Fathead Minnow

    EPA Science Inventory

    In this work, a 96-well plate estrogen receptor binding assay was developed to facilitate the direct comparison of chemical binding to full-length recombinant estrogen receptors across vertebrate classes. Receptors were generated in a baculovirus expression system. This approach ...

  10. Effects of 3-beta-diol, an androgen metabolite with intrinsic estrogen-like effects, in modulating the aquaporin-9 expression in the rat efferent ductules

    PubMed Central

    Picciarelli-Lima, Patrícia; Oliveira, André G; Reis, Adelina M; Kalapothakis, Evanguedes; Mahecha, Germán AB; Hess, Rex A; Oliveira, Cleida A

    2006-01-01

    Background Fluid homeostasis is critical for normal function of the male reproductive tract and aquaporins (AQP) play an important role in maintenance of this water and ion balance. Several AQPs have been identified in the male, but their regulation is not fully comprehended. Hormonal regulation of AQPs appears to be dependent on the steroid in the reproductive tract region. AQP9 displays unique hormonal regulation in the efferent ductules and epididymis, as it is regulated by both estrogen and dihydrotestosterone (DHT) in the efferent ductules, but only by DHT in the initial segment epididymis. Recent data have shown that a metabolite of DHT, 5-alpha-androstane-3-beta-17-beta-diol (3-beta-diol), once considered inactive, is also present in high concentrations in the male and indeed has biological activity. 3-beta-diol does not bind to the androgen receptor, but rather to estrogen receptors ER-alpha and ER-beta, with higher affinity for ER-beta. The existence of this estrogenic DHT metabolite has raised the possibility that estradiol may not be the only estrogen to play a major role in the male reproductive system. Considering that both ER-alpha and ER-beta are highly expressed in efferent ductules, we hypothesized that the DHT regulation of AQP9 could be due to the 3-beta-diol metabolite. Methods To test this hypothesis, adult male rats were submitted to surgical castration followed by estradiol, DHT or 3-beta-diol replacement. Changes in AQP9 expression in the efferent ductules were investigated by using immunohistochemistry and Western blotting assay. Results Data show that, after castration, AQP9 expression was significantly reduced in the efferent ductules. 3-beta-diol injections restored AQP9 expression, similar to DHT and estradiol. The results were confirmed by Western blotting assay. Conclusion This is the first evidence that 3-beta-diol has biological activity in the male reproductive tract and that this androgen metabolite has estrogen-like activity in

  11. Steroid receptor coactivator-1 mediates estrogenic actions to prevent body weight gain in female mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estrogen receptor-alpha (ERalpha) expressed by hypothalamic proopiomelanocortin and steroidogenic factor-1 neurons largely mediates the antiobesity effects of estrogens in females. However, the critical molecular events that are coupled to ERalpha and mediate estrogenic effects on energy balance rem...

  12. Distinct mechanisms of endocrine disruption of DDT-related pesticides toward estrogen receptor α and estrogen-related receptor γ.

    PubMed

    Zhuang, Shulin; Zhang, Jing; Wen, Yuezhong; Zhang, Chunlong; Liu, Weiping

    2012-11-01

    Dichlorodiphenyltrichloroethane (DDT) is ubiquitous in the environment, and the exposure to DDT and its related pesticides has long been linked to endocrine disruption. The mechanism of endocrine disruption toward targeted receptors, however, remains unclear. Probing the molecular recognition of DDT analogs by targeted receptors at the atomic level is critical for deciphering this mechanism. Molecular dynamics (MD) simulations were applied to probe the molecular recognition process of DDT and its five analogs, including dichlordiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD), methoxychlor (MXC), p,p'-hydroxy-DDT (HPTE), and dicofol by human estrogen receptor (ER) α and human ER-related receptor (ERR) γ. Van der Waals interactions mainly drive the interactions of DDT analogs with ERα ligand-binding domain (LBD) and ERRγ LBD. Minor structural changes of DDT analogs in the number and position of chlorine and phenolic hydroxyl moiety cause differences in binding modes through aromatic stacking and hydrogen bonding and thus affect differently conformational changes of ERα LBD and ERRγ LBD. The binding of DDT analogs affects the helix 12 orientation of ERα LBD but causes no rearrangement of helix 12 of ERRγ LBD. These results extend our understanding of how DDT analogs exert their estrogen-disrupting effects toward different receptors via multiple mechanisms.

  13. Novel biosensors for the detection of estrogen receptor ligands.

    PubMed

    De, Siddhartha; Macara, Ian G; Lannigan, Deborah A

    2005-08-01

    There exists a significant need for the detection of novel estrogen receptor (ER) ligands for pharmaceutical uses, especially for treating complications associated with menopause. We have developed fluorescence resonance energy transfer (FRET)-based biosensors that permit the direct in vitro detection of ER ligands. These biosensors contain an ER ligand-binding domain (LBD) flanked by the FRET donor fluorophore, cyan fluorescent protein (CFP), and the acceptor fluorophore, yellow fluorescent protein (YFP). The ER-LBD has been modified so that Ala 430 has been changed to Asp, which increases the magnitude of the FRET signal in response to ligand-binding by more than four-fold compared to the wild-type LBD. The binding of agonists can be distinguished from that of antagonists on the basis of the distinct ligand-induced conformations in the ER-LBD. The approach to binding equilibrium occurs within 30min, and the FRET signal is stable over 24h. The biosensor demonstrates a high signal-to-noise, with a Z' value (a statistical determinant of assay quality) of 0.72. The affinity of the ER for different ligands can be determined using a modified version of the biosensor in which a truncated YFP and an enhanced CFP are used. Thus, we have developed platforms for high-throughput screens for the identification of novel estrogen receptor ligands. Moreover, we have demonstrated that this FRET technology can be applied to other nuclear receptors, such as the androgen receptor.

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

    PubMed Central

    Seeger, Bettina; Klawonn, Frank; Nguema Bekale, Boris; Steinberg, Pablo

    2016-01-01

    Consumers of fruits and vegetables are frequently exposed to small amounts of hormonally active pesticides, some of them sharing a common mode of action such as the activation of the human estrogen receptor α (hERα) or β (hERβ). Therefore, it is of particular importance to evaluate risks emanating from chemical mixtures, in which the individual pesticides are present at human-relevant concentrations, below their corresponding maximum residue levels. Binary and ternary iso-effective mixtures of estrogenic pesticides at effect concentrations eliciting a 1 or 10% effect in the presence or absence of 17β-estradiol were tested experimentally at the hERα in the yeast-based estrogen screen (YES) assay as well as in the human U2-OS cell-based ERα chemical-activated luciferase gene expression (ERα CALUX) assay and at the hERβ in the ERβ CALUX assay. The outcome was then compared to predictions calculated by means of concentration addition. In most cases, additive effects were observed with the tested combinations in all three test systems, an observation that supports the need to expand the risk assessment of pesticides and consider cumulative risk assessment. An additional testing of mixture effects at the hERβ showed that most test substances being active at the hERα could also elicit additive effects at the hERβ, but the hERβ was less sensitive. In conclusion, effects of the same ligands at the hERα and the hERβ could influence the estrogenic outcome under physiological conditions. PMID:26812056

  15. Bazedoxifene: a novel selective estrogen receptor modulator for postmenopausal osteoporosis.

    PubMed

    de Villiers, T J

    2010-06-01

    Several new selective estrogen receptor modulators (SERMs) are currently under clinical development for the prevention and/or treatment of postmenopausal osteoporosis, with the goal of optimizing the estrogen receptor agonist/antagonist activity in target tissues. Bazedoxifene is a novel SERM under clinical investigation for the prevention and treatment of postmenopausal osteoporosis. Emerging clinical data have shown that bazedoxifene is effective in preventing bone loss and osteoporotic fractures in postmenopausal women, with no evidence of breast or endometrial stimulation. Two large, prospective, international phase 3 studies have been completed. In postmenopausal women at risk for osteoporosis, bazedoxifene has been shown to preserve bone mineral density and to reduce bone turnover. In postmenopausal women with osteoporosis, bazedoxifene has demonstrated significant protection against new vertebral fractures and against non-vertebral fractures in women at higher fracture risk. The treatment effects of bazedoxifene were supported by findings from independent re-analyses using the Fracture Risk Assessment Tool (FRAX), which showed that bazedoxifene significantly reduced the risk of all clinical and morphometric vertebral fracture and of non-vertebral fracture in women at or above a FRAX-based threshold. Bazedoxifene was generally safe and well tolerated in the phase 3 studies and showed neutral effects on the breast and an excellent endometrial safety profile; such attributes allow for the partnering of bazedoxifene with conjugated estrogens for menopausal symptom relief. Collectively, these results suggest that bazedoxifene may be a promising new therapy for the prevention and treatment of postmenopausal osteoporosis as a monotherapy or in combination with conjugated estrogens in menopausal hormone therapy.

  16. Sex differences in opioid analgesia and addiction: interactions among opioid receptors and estrogen receptors

    PubMed Central

    2013-01-01

    Opioids are widely used as the pain reliever and also notorious for being addictive drugs. Sex differences in the opioid analgesia and addiction have been reported and investigated in human subjects and animal models. Yet, the molecular mechanism underlying the differences between males and females is still unclear. Here, we reviewed the literature describing the sex differences in analgesic responses and addiction liabilities to clinically relevant opioids. The reported interactions among opioids, estrogens, opioid receptors, and estrogen receptors are also evaluated. We postulate that the sex differences partly originated from the crosstalk among the estrogen and opioid receptors when stimulated by the exogenous opioids, possibly through common secondary messengers and the downstream gene transcriptional regulators. PMID:24010861

  17. Sex differences in opioid analgesia and addiction: interactions among opioid receptors and estrogen receptors.

    PubMed

    Lee, Cynthia Wei-Sheng; Ho, Ing-Kang

    2013-09-08

    Opioids are widely used as the pain reliever and also notorious for being addictive drugs. Sex differences in the opioid analgesia and addiction have been reported and investigated in human subjects and animal models. Yet, the molecular mechanism underlying the differences between males and females is still unclear. Here, we reviewed the literature describing the sex differences in analgesic responses and addiction liabilities to clinically relevant opioids. The reported interactions among opioids, estrogens, opioid receptors, and estrogen receptors are also evaluated. We postulate that the sex differences partly originated from the crosstalk among the estrogen and opioid receptors when stimulated by the exogenous opioids, possibly through common secondary messengers and the downstream gene transcriptional regulators.

  18. Potency and characterization of estrogen-receptor agonists in United Kingdom estuarine sediments.

    PubMed

    Thomas, Kevin V; Balaam, Jan; Hurst, Mark; Nedyalkova, Zoya; Mekenyan, Ovanes

    2004-02-01

    The activity of estrogen-receptor (ER) agonists in sediments collected from the United Kingdom (UK) estuaries was assessed using the in vitro recombinant yeast estrogen screen (YES assay). The YES assay was successfully used to determine the in vitro ER agonist potency of pore waters and solvent extracts of sediments collected from UK estuaries. Estrogen-receptor agonists were detected in 66% of the pore water samples and in 91% of the sediment solvent extracts tested. The pore waters tested had ER agonist potencies from less than 2 to 68 ng 17beta-estradiol (E2) L(-1), whereas sediment extracts had potencies from less than 0.2 to 13 microg E2 kg(-1). A toxicity identification evaluation approach using bioassay-directed fractionation was used in an attempt to identify the ER agonists in extracts of sediments collected from the Tyne and Tees estuaries (UK). Gas chromatography-mass spectrometry was used to provide lists of compounds in the fractions obtained that were evaluated for known ER agonist activity using published data and an ER quantitative structure-activity relationship model. Toxicity identification evaluation characterization failed to identify any ER agonists in pore water extracts; however, three compounds in sediment solvent extracts were identified as ER agonists. Nonylphenol, cinnarizine, and cholesta-4,6-dien-3-one were identified in the sample collected from the Tyne estuary. Important ER agonist substances that contaminate marine sediments remain unidentified. The present study as well as previous work on effluents point toward the involvement of natural products in the estrogenic burdens of marine sediments. Further work is required to establish the relative contribution of natural products and anthropogenic chemicals to current environmental impacts in the context of the Oslo and Paris Commission strategy to eliminate hazardous substances by 2020.

  19. Hispolon inhibits the growth of estrogen receptor positive human breast cancer cells through modulation of estrogen receptor alpha

    SciTech Connect

    Jang, Eun Hyang; Jang, Soon Young; Cho, In-Hye; Hong, Darong; Jung, Bom; Park, Min-Ju; Kim, Jong-Ho

    2015-08-07

    Human estrogen receptor α (ERα) is a nuclear transcription factor that is a major therapeutic target in breast cancer. The transcriptional activity of ERα is regulated by certain estrogen-receptor modulators. Hispolon, isolated from Phellinus linteus, a traditional medicinal mushroom called Sanghwang in Korea, has been used to treat various pathologies, such as inflammation, gastroenteric disorders, lymphatic diseases, and cancers. In this latter context, Hispolon has been reported to exhibit therapeutic efficacy against various cancer cells, including melanoma, leukemia, hepatocarcinoma, bladder cancer, and gastric cancer cells. However, ERα regulation by Hispolon has not been reported. In this study, we investigated the effects of Hispolon on the growth of breast cancer cells. We found that Hispolon decreased expression of ERα at both mRNA and the protein levels in MCF7 and T47D human breast cancer cells. Luciferase reporter assays showed that Hispolon decreased the transcriptional activity of ERα. Hispolon treatment also inhibited expression of the ERα target gene pS2. We propose that Hispolon, an anticancer drug extracted from natural sources, inhibits cell growth through modulation of ERα in estrogen-positive breast cancer cells and is a candidate for use in human breast cancer chemotherapy. - Highlights: • Hispolon decreased ERα expression at both mRNA and protein levels. • Hispolon decreased ERα transcriptional activity. • Hispolon treatment inhibited expression of ERα target gene pS2. • Shikonin is a candidate chemotherapeutic target in the treatment of human breast cancer.

  20. The Role of Estrogen Related Receptor in Modulating Estrogen Receptor Mediated Transcription in Breast Cancer Cells

    DTIC Science & Technology

    2005-04-01

    receptors ) by demonstrating that mitochondrial biogenesis and fatty acid P- oxidation , processes ERRa is known to regulate , are robustly...gluconeogenesis, and fatty acid oxidation (Lin 2003; Puigserver 1998; Wu 1999; Yoon 2001). In addition to its activity on a number of nuclear receptors , this...in target cells. They were generated by replacing the receptor interaction domains in peroxisome proliferator activated receptor

  1. Inhibition of angiogenesis by selective estrogen receptor modulators through blockade of cholesterol trafficking rather than estrogen receptor antagonism.

    PubMed

    Shim, Joong Sup; Li, Ruo-Jing; Lv, Junfang; Head, Sarah A; Yang, Eun Ju; Liu, Jun O

    2015-06-28

    Selective estrogen receptor modulators (SERM) including tamoxifen are known to inhibit angiogenesis. However, the underlying mechanism, which is independent of their action on the estrogen receptor (ER), has remained largely unknown. In the present study, we found that tamoxifen and other SERM inhibited cholesterol trafficking in endothelial cells, causing a hyper-accumulation of cholesterol in late endosomes/lysosomes. Inhibition of cholesterol trafficking by tamoxifen was accompanied by abnormal subcellular distribution of vascular endothelial growth factor receptor-2 (VEGFR2) and inhibition of the terminal glycosylation of the receptor. Tamoxifen also caused perinuclear positioning of lysosomes, which in turn trapped the mammalian target of rapamycin (mTOR) in the perinuclear region of endothelial cells. Abnormal distribution of VEGFR2 and mTOR and inhibition of VEGFR2 and mTOR activities by tamoxifen were significantly reversed by addition of cholesterol-cyclodextrin complex to the culture media of endothelial cells. Moreover, high concentrations of tamoxifen inhibited endothelial and breast cancer cell proliferation in a cholesterol-dependent, but ER-independent, manner. Together, these results unraveled a previously unrecognized mechanism of angiogenesis inhibition by tamoxifen and other SERM, implicating cholesterol trafficking as an attractive therapeutic target for cancer treatment.

  2. Tamoxifen regulation of bone growth and endocrine function in the ovariectomized rat: discrimination of responses involving estrogen receptor α/estrogen receptor β, G protein-coupled estrogen receptor, or estrogen-related receptor γ using fulvestrant (ICI 182780).

    PubMed

    Fitts, James M; Klein, Robert M; Powers, C Andrew

    2011-07-01

    Tamoxifen is a selective estrogen receptor (ER) modulator, but it is also a deactivating ligand for estrogen-related receptor-γ (ERRγ) and a full agonist for the G protein-coupled estrogen receptor (GPER). Fulvestrant is a selective ER down-regulator that lacks agonist effects on ERα/ERβ, is inactive on ERRγ, but acts as a full agonist on GPER. Fulvestrant effects on tamoxifen actions on uterine and somatic growth, bone, the growth hormone (GH)-insulin-like growth factor I (IGF-I) axis, and pituitary prolactin were analyzed to pharmacologically discriminate tamoxifen effects that may be mediated by ERα/ERβ versus ERRγ versus GPER. Ovariectomized rats received tamoxifen (0.6 mg/kg/daily) plus fulvestrant at 0, 3, 6, or 12 mg/kg/daily for 5 weeks; controls received vehicle or 6 mg/kg fulvestrant daily. Tamoxifen effects to increase uterine weight, decrease serum IGF-I, increase pituitary prolactin, and increase bone mineral density could be fully blocked by fulvestrant, indicating mediation by ERα/ERβ. Tamoxifen effects to decrease pituitary GH, tibia length, and body weight were only partially blocked by fulvestrant, indicating involvement of mechanisms unrelated to ERα/ERβ. Fulvestrant did not inhibit tamoxifen actions to reduce total pituitary protein, again indicating effects not mediated by ERα/ERβ. Tamoxifen actions to reduce serum GH were mimicked rather than inhibited by fulvestrant, pharmacological features consistent with GPER involvement. However, fulvestrant alone increased IGF-I and also blocked tamoxifen-evoked IGF-I decreases; thus fulvestrant effects on serum GH might reflect increased IGF-I feedback inhibition. Fulvestrant alone had no effect on the other parameters. The findings indicate that mechanisms unrelated to ERα/ERβ contribute to tamoxifen effects on body weight, bone growth, and pituitary function.

  3. Estrogen-related receptor alpha and cancer: axis of evil.

    PubMed

    Ranhotra, Harmit S

    2015-01-01

    Cancer is perhaps the fastest growing non-communicable disease in the human population worldwide. Although the molecular mechanism of cancer initiation and progression is known to some extent, however, the majority of pathways responsible for its onset, development and progression are largely unknown. Many members of the nuclear receptors (NRs) superfamily of transcriptional factors have key roles in cancer. Estrogen-related receptor alpha (ERRα) is one of the members of the NR superfamily and studies have linked it with a wide variety of cancers. In endocrine-related cancers such as breast cancer, ERRα regulates a number of target genes directing cell proliferation and growth independent of estrogen receptor alpha (ERα). Knockdown of ERRα in a number of cancer tissues and cell lines significantly reduced tumor growth and malignancy indicating dependence on ERRα activity. The pro-angiogenesis factor vascular endothelial growth factor expression has been shown to be regulated by ERRα and has implications in several types of cancer. The effect of ERRα on cancers seems to be multipronged via regulation of cell cycle regulators, osteopontin, hypoxia inducible factor-1 as well as several energy metabolism genes that are part of glycolysis, TCA cycle, lipogenesis, etc., providing a metabolic twist to cancer. In this article, the action of ERRα on various types of cancers including new developments in this field shall be reviewed.

  4. Oxytocin and Estrogen Receptor β in the Brain: An Overview

    PubMed Central

    Acevedo-Rodriguez, Alexandra; Mani, Shaila K.; Handa, Robert J.

    2015-01-01

    Oxytocin (OT) is a neuropeptide synthesized primarily by neurons of the paraventricular and supraoptic nuclei of the hypothalamus. These neurons have axons that project into the posterior pituitary and release OT into the bloodstream to promote labor and lactation; however, OT neurons also project to other brain areas where it plays a role in numerous brain functions. OT binds to the widely expressed OT receptor (OTR), and, in doing so, it regulates homeostatic processes, social recognition, and fear conditioning. In addition to these functions, OT decreases neuroendocrine stress signaling and anxiety-related and depression-like behaviors. Steroid hormones differentially modulate stress responses and alter OTR expression. In particular, estrogen receptor β activation has been found to both reduce anxiety-related behaviors and increase OT peptide transcription, suggesting a role for OT in this estrogen receptor β-mediated anxiolytic effect. Further research is needed to identify modulators of OT signaling and the pathways utilized and to elucidate molecular mechanisms controlling OT expression to allow better therapeutic manipulations of this system in patient populations. PMID:26528239

  5. Mammalian. beta. /sub 1/- and. beta. /sub 2/-adrenergic receptors: immunological and structural comparison

    SciTech Connect

    Moxham, C.P.; George, S.T.; Graziano, M.P.; Brandwein, H.J.; Malbon, C.C.

    1986-11-05

    ..beta../sub 1/- and ..beta../sub 2/-adrenergic receptors, pharmacologically distinct proteins, have been reported to be structurally dissimilar. In the present study three techniques were employed to compare the nature of mammalian ..beta../sub 1/- and ..beta../sub 2/-adrenergic receptors. Antibodies against each of the receptor subtypes were raised separately. Polyclonal antisera against ..beta../sub 1/-receptors of rat fat cells were raised in mice, and antisera against ..beta../sub 2/-receptors of guinea pig lung were raised in rabbits. Receptors purified from rat fat cells (..beta../sub 1/-), S49 mouse lymphoma cells (..beta../sub 2/-), and rat liver (..beta../sub 2/-) were probed with these antisera. Each anti-receptor antisera demonstrated the ability to immunoprecipitate purified receptors of both ..beta../sub 1/- and ..beta../sub 2/-subtypes. The mobility of ..beta..-receptors subjected to polyacrylamide gel electrophoresis was probed using antireceptor antibodies and nitrocellulose blots of the gels. Fat cell ..beta../sub 1/-adrenergic receptors display M/sub r/ = 67,000 under reducing conditions and M/sub r/ = 54,000 under nonreducing conditions, as previously reported. Both ..beta../sub 1/- and ..beta../sub 2/-receptors displayed this same shift in electrophoretic mobility observed in the presence as compared to the absence of disulfide bridge-reducing agents, as detected both by autoradiography of the radiolabeled receptors and by immunoblotting of native receptors. Finally, isoelectric focusing of purified radioiodinated ..beta../sub 1/- and ..beta../sub 2/-adrenergic receptors revealed identical isoelectric points. These data are the first to provide analyses of immunological, structural, and biochemical features of ..beta../sub 1/- and ..beta../sub 2/-subtypes in tandem and underscore the structural similarities that exist between these pharmacologically distinct receptors.

  6. Prothymosin Alpha Selectively Enhances Estrogen Receptor Transcriptional Activity by Interacting with a Repressor of Estrogen Receptor Activity

    PubMed Central

    Martini, Paolo G. V.; Delage-Mourroux, Regis; Kraichely, Dennis M.; Katzenellenbogen, Benita S.

    2000-01-01

    We find that prothymosin alpha (PTα) selectively enhances transcriptional activation by the estrogen receptor (ER) but not transcriptional activity of other nuclear hormone receptors. This selectivity for ER is explained by PTα interaction not with ER, but with a 37-kDa protein denoted REA, for repressor of estrogen receptor activity, a protein that we have previously shown binds to ER, blocking coactivator binding to ER. We isolated PTα, known to be a chromatin-remodeling protein associated with cell proliferation, using REA as bait in a yeast two-hybrid screen with a cDNA library from MCF-7 human breast cancer cells. PTα increases the magnitude of ERα transcriptional activity three- to fourfold. It shows lesser enhancement of ERβ transcriptional activity and has no influence on the transcriptional activity of other nuclear hormone receptors (progesterone receptor, glucocorticoid receptor, thyroid hormone receptor, or retinoic acid receptor) or on the basal activity of ERs. In contrast, the steroid receptor coactivator SRC-1 increases transcriptional activity of all of these receptors. Cotransfection of PTα or SRC-1 with increasing amounts of REA, as well as competitive glutathione S-transferase pulldown and mammalian two-hybrid studies, show that REA competes with PTα (or SRC-1) for regulation of ER transcriptional activity and suppresses the ER stimulation by PTα or SRC-1, indicating that REA can function as an anticoactivator in cells. Our data support a model in which PTα, which does not interact with ER, selectively enhances the transcriptional activity of the ER but not that of other nuclear receptors by recruiting the repressive REA protein away from ER, thereby allowing effective coactivation of ER with SRC-1 or other coregulators. The ability of PTα to directly interact in vitro and in vivo with REA, a selective coregulator of the ER, thereby enabling the interaction of ER with coactivators, appears to explain its ability to selectively enhance

  7. Polyester monomers lack ability to bind and activate both androgenic and estrogenic receptors as determined by in vitro and in silico methods.

    PubMed

    Osimitz, Thomas G; Welsh, William J; Ai, Ni; Toole, Colleen

    2015-01-01

    The paper presents results from the screening of seven monomers used by Eastman Chemical to make various polymers. Ethylene glycol, diethylene glycol, polytetramethylene glycol, isophthalic acid, monosodium-5-sulfoisophthalic acid, 1,4-cyclohexanedicarboxylic acid, and dimethylcyclohexanedicarboxylate were screened for potential androgenicity or estrogenicity. The following studies were conducted: QSAR for binding to the AR and ER, in vitro Androgen Receptor Binding Assay, in vitro Estrogen Receptor Binding Assays (alpha and beta isoforms), in vitro Androgen Receptor Transactivation Assay in human cells, and in vitro Estrogen Receptor Transactivation Assay in human cells. None of the QSAR models predicted that any of the monomers possessed appreciable binding affinity for either AR or ER. Binding assays showed no evidence of interaction with either the AR or the alpha or beta ER receptors. Similarly, the AR and ER transactivation assays were negative. Moreover, six of the seven monomers have been subjected to 13-week and developmental toxicity studies in rats with no androgen- or estrogen-related effects being noted. Given the negative results of the in vitro screening assays (except PMG which demonstrated cytotoxicity) as well as available repeated dose and developmental and reproductive studies, the data suggest that none of the monomers tested exhibit androgenic or estrogenic hazards.

  8. The Estrogen Receptor-β Expression in De Quervain's Disease.

    PubMed

    Shen, Po-Chuan; Wang, Ping-Hui; Wu, Po-Ting; Wu, Kuo-Chen; Hsieh, Jeng-Long; Jou, I-Ming

    2015-11-04

    Stenosing tenosynovitis of the first dorsal compartment of the wrist (a.k.a. de Quervain's disease) is common but how estrogen is involved is still unknown. We previously reported that inflammation was involved in the pathogenesis of this ailment. In the present study, we extended our investigation of estrogen receptor (ER)-β expression to determine whether estrogen is involved in the pathogenesis of de Quervain's. Intraoperative retinaculum samples were collected from 16 patients with the ailment. Specimens were histologically graded by collagen structure and immunohistochemically evaluated by quantifying the expression of ER-β, interleukin (IL)-1β and IL-6 (inflammatory cytokines), cyclooxygenase (COX)-2 (an inflammatory enzyme), and vascular endothelial growth factor (VEGF), and Von Willebrand's factor (vWF). De Quervain's occurs primarily in women. The female:male ratio in our study was 7:1. We found that ER-β expression in the retinaculum was positively correlated with disease grade and patient age. Additionally, disease severity was associated with inflammatory factors--IL-1β and IL-6, COX-2, and VEGF and vWF in tenosynovial tissue. The greater the levels of ER-β expression, tissue inflammation, and angiogenesis are, the more severe de Quervain's disease is. ER-β might be a useful target for novel de Quervain's disease therapy.

  9. G protein-coupled estrogen receptor protects from atherosclerosis.

    PubMed

    Meyer, Matthias R; Fredette, Natalie C; Howard, Tamara A; Hu, Chelin; Ramesh, Chinnasamy; Daniel, Christoph; Amann, Kerstin; Arterburn, Jeffrey B; Barton, Matthias; Prossnitz, Eric R

    2014-12-23

    Coronary atherosclerosis and myocardial infarction in postmenopausal women have been linked to inflammation and reduced nitric oxide (NO) formation. Natural estrogen exerts protective effects on both processes, yet also displays uterotrophic activity. Here, we used genetic and pharmacologic approaches to investigate the role of the G protein-coupled estrogen receptor (GPER) in atherosclerosis. In ovary-intact mice, deletion of gper increased atherosclerosis progression, total and LDL cholesterol levels and inflammation while reducing vascular NO bioactivity, effects that were in some cases aggravated by surgical menopause. In human endothelial cells, GPER was expressed on intracellular membranes and mediated eNOS activation and NO formation, partially accounting for estrogen-mediated effects. Chronic treatment with G-1, a synthetic, highly selective small molecule agonist of GPER, reduced postmenopausal atherosclerosis and inflammation without uterotrophic effects. In summary, this study reveals an atheroprotective function of GPER and introduces selective GPER activation as a novel therapeutic approach to inhibit postmenopausal atherosclerosis and inflammation in the absence of uterotrophic activity.

  10. G Protein-coupled Estrogen Receptor Protects from Atherosclerosis

    PubMed Central

    Meyer, Matthias R.; Fredette, Natalie C.; Howard, Tamara A.; Hu, Chelin; Ramesh, Chinnasamy; Daniel, Christoph; Amann, Kerstin; Arterburn, Jeffrey B.; Barton, Matthias; Prossnitz, Eric R.

    2014-01-01

    Coronary atherosclerosis and myocardial infarction in postmenopausal women have been linked to inflammation and reduced nitric oxide (NO) formation. Natural estrogen exerts protective effects on both processes, yet also displays uterotrophic activity. Here, we used genetic and pharmacologic approaches to investigate the role of the G protein-coupled estrogen receptor (GPER) in atherosclerosis. In ovary-intact mice, deletion of gper increased atherosclerosis progression, total and LDL cholesterol levels and inflammation while reducing vascular NO bioactivity, effects that were in some cases aggravated by surgical menopause. In human endothelial cells, GPER was expressed on intracellular membranes and mediated eNOS activation and NO formation, partially accounting for estrogen-mediated effects. Chronic treatment with G-1, a synthetic, highly selective small molecule agonist of GPER, reduced postmenopausal atherosclerosis and inflammation without uterotrophic effects. In summary, this study reveals an atheroprotective function of GPER and introduces selective GPER activation as a novel therapeutic approach to inhibit postmenopausal atherosclerosis and inflammation in the absence of uterotrophic activity. PMID:25532911

  11. Estrogen and progesterone receptor isoforms expression in the stomach of Mongolian gerbils

    PubMed Central

    Saqui-Salces, Milena; Neri-Gómez, Teresa; Gamboa-Dominguez, Armando; Ruiz-Palacios, Guillermo; Camacho-Arroyo, Ignacio

    2008-01-01

    AIM: We studied the estrogen receptor (ER) and progesterone receptor (PR) isoforms expression in gastric antrum and corpus of female gerbils and their regulation by estradiol (E2) and progesterone (P4). METHODS: Ovariectomized adult female gerbils were subcutaneously treated with E2, and E2 + P4. Uteri and stomachs were removed, the latter were cut along the greater curvature, and antrum and corpus were excised. Proteins were immunoblotted using antibodies that recognize ER-alpha, ER-beta, and PR-A and PR-B receptor isoforms. Tissues from rats treated in the same way were used as controls. RESULTS: Specific bands were detected for ER-alpha (68 KDa), and PR isoforms (85 and 120 KDa for PR-A and PR-B isoforms, respectively) in uteri, gastric antrum and corpus. We could not detect ER-beta isoform. PR isoforms were not regulated by E2 or P4 in uterus and gastric tissues of gerbils. ER-alpha isoform content was significantly down-regulated by E2 in the corpus, but not affected by hormones in uterus and gastric antrum. CONCLUSION: The presence of ER-alpha and PR isoforms in gerbils stomach suggests that E2 and P4 actions in this organ are in part mediated by their nuclear receptors. PMID:18837087

  12. Dietary Estrogens Act through Estrogen Receptor-Mediated Processes and Show No Antiestrogenicity in Cultured Breast Cancer Cells.

    PubMed Central

    Makela, S; Davis, VL; Tally, WC; Korkman, J; Salo, L; Vihko, R; Santti, R; Korach, KS

    1994-01-01

    Dietary estrogens are believed to exert their estrogenic or antiestrogenic (chemopreventive) action in estrogen responsive cells by interacting with the estrogen receptor (ER). The present study was undertaken to evaluate a direct role of ER in estrogenic or antiestrogenic activities of three dietary estrogens (coumestrol, genistein and zearalenone). HeLa cells were transiently co-transfected with an expression vector for ER and an estrogen-responsive reporter gene construct. Coumestrol, genistein, and zearalenone all increased the activity of the reporter gene, only in the presence of the ER, and the activation was blocked with the ER antagonist ICI 164,384, demonstrating an ER-specific, agonist response. In addition, in MCF-7 cells, coumestrol and zearalenone increased the expression of the estrogen-responsive pS2 gene. Coumestrol and genistein inhibited the purified estrogen-specific 17ß-hydroxysteroid oxidoreductase enzyme and the conversion of estrone to 17ß-estradiol in T-47D cells, which contain this enzyme. However, they did not inhibit the estrone-induced proliferation of T-47D cells. In conclusion, coumestrol, genistein, and zearalenone are all potent estrogens in vitro, and they act through ER mediated mechanism. Our findings give no evidence to support the idea that these compounds act as antiestrogens through competition for the binding sites of ER or by inhibition of the conversion of estrone to 17ß-estradiol in breast cancer cells, since this effect was nullified by their agonist action on cell proliferation. Therefore, their suggested chemopreventive action in estrogen-related cancers must be mediated through other mechanisms. Images Figure 2. A Figure 2. B Figure 2. C Figure 2. D Figure 2. E Figure 3. A Figure 3. B Figure 4. A Figure 4. B Figure 4. C Figure 4. D Figure 4. E Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. A Figure 9. B Figure 9. C PMID:9679118

  13. Estrogen regulation of chicken riboflavin carrier protein gene is mediated by ERE half sites without direct binding of estrogen receptor.

    PubMed

    Bahadur, Urvashi; Ganjam, Goutham K; Vasudevan, Nandini; Kondaiah, Paturu

    2005-02-28

    Estrogen is an important steroid hormone that mediates most of its effects on regulation of gene expression by binding to intracellular receptors. The consensus estrogen response element (ERE) is a 13bp palindromic inverted repeat with a three nucleotide spacer. However, several reports suggest that many estrogen target genes are regulated by diverse elements, such as imperfect EREs and ERE half sites (ERE 1/2), which are either the proximal or the distal half of the palindrome. To gain more insight into ERE half site-mediated gene regulation, we used a region from the estrogen-regulated chicken riboflavin carrier protein (RCP) gene promoter that contains ERE half sites. Using moxestrol, an analogue of estrogen and transient transfection of deletion and mutation containing RCP promoter/reporter constructs in chicken hepatoma (LMH2A) cells, we identified an estrogen response unit (ERU) composed of two consensus ERE 1/2 sites and one non-consensus ERE 1/2 site. Mutation of any of these sites within this ERU abolishes moxestrol response. Further, the ERU is able to confer moxestrol responsiveness to a heterologous promoter. Interestingly, RCP promoter is regulated by moxestrol in estrogen responsive human MCF-7 cells, but not in other cell lines such as NIH3T3 and HepG2 despite estrogen receptor-alpha (ER-alpha) co transfection. Electrophoretic mobility shift assays (EMSAs) with promoter regions encompassing the half sites and nuclear extracts from LMH2A cells show the presence of a moxestrol-induced complex that is abolished by a polyclonal anti-ERalpha antibody. Surprisingly, estrogen receptor cannot bind to these promoter elements in isolation. Thus, there appears to be a definite requirement for some other factor(s) in addition to estrogen receptor, for the generation of a suitable response of this promoter to estrogen. Our studies therefore suggest a novel mechanism of gene regulation by estrogen, involving ERE half sites without direct binding of ER to the

  14. Telomerase activity, estrogen receptors (α, β), Bcl-2 expression in human breast cancer and treatment response

    PubMed Central

    Murillo-Ortiz, Blanca; Astudillo-De la Vega, Horacio; Castillo-Medina, Sebastian; Malacara, JM; Benitez-Bribiesca, Luis

    2006-01-01

    Background The mechanism for maintaining telomere integrity is controlled by telomerase, a ribonucleoprotein enzyme that specifically restores telomere sequences, lost during replication by means of an intrinsic RNA component as a template for polymerization. Among the telomerase subunits, hTERT (human telomerase reverse transcriptase) is expressed concomitantly with the activation of telomerase. The role of estrogens and their receptors in the transcriptional regulation of hTERT has been demonstrated. The current study determines the possible association between telomerase activity, the expression of both molecular forms of estrogen receptor (ERα and ERβ) and the protein bcl-2, and their relative associations with clinical parameters. Methods Tissue samples from 44 patients with breast cancer were used to assess telomerase activity using the TRAP method and the expression of ERα, ERβ and bcl-2 by means of immunocytochemical techniques. Results Telomerase activity was detected in 59% of the 44 breast tumors examined. Telomerase activity ranged from 0 to 49.93 units of total product generated (TPG). A correlation was found between telomerase activity and differentiation grade (p = 0.03). The only significant independent marker of response to treatment was clinical stage. We found differences between the frequency of expression of ERα (88%) and ERβ (36%) (p = 0.007); bcl-2 was expressed in 79.5% of invasive breast carcinomas. We also found a significant correlation between low levels of telomerase activity and a lack of ERβ expression (p = 0.03). Conclusion Lower telomerase activity was found among tumors that did not express estrogen receptor beta. This is the first published study demonstrating that the absence of expression of ERβ is associated with low levels of telomerase activity. PMID:16911782

  15. [Roles of G protein-coupled estrogen receptor in the male reproductive system].

    PubMed

    Chen, Kai-hong; Zhang, Xian; Jiang, Xue-wu

    2016-02-01

    The G protein-coupled estrogen receptor (GPER), also known as G protein-coupled receptor 30 (GPR30), was identified in the recent years as a functional membrane receptor different from the classical nuclear estrogen receptors. This receptor is widely expressed in the cortex, cerebellum, hippocampus, heart, lung, liver, skeletal muscle, and the urogenital system. It is responsible for the mediation of nongenomic effects associated with estrogen and its derivatives, participating in the physiological activities of the body. The present study reviews the molecular structure, subcellular localization, signaling pathways, distribution, and function of GPER in the male reproductive system.

  16. Development of a Competitive Binding Assay System with Recombinant Estrogen Receptors from Multiple Species

    EPA Science Inventory

    ABSTRACT In the current study, we developed a new system using full-length recombinant baculovirus-expressed estrogen receptors which allows for direct comparison of binding across species. Estrogen receptors representing five vertebrate classes were compared: human (hERα), quai...

  17. Stimulation of Estrogen Receptor Signaling in Breast Cancer by a Novel Chaperone Synuclein Gamma

    DTIC Science & Technology

    2006-06-01

    AD_________________ Award Number: W81XWH- 04 -1-0569 TITLE: Stimulation of estrogen receptor...Stimulation of estrogen receptor signaling in breast cancer by a novel chaperone 5a. CONTRACT NUMBER synuclein gamma 5b. GRANT NUMBER W81XWH- 04 -1...UNIT NUMBER 7 . PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER North Shore University Hospital

  18. Oxytocin, vasopressin and estrogen receptor gene expression in relation to social recognition in female mice

    PubMed Central

    Clipperton-Allen, Amy E.; Lee, Anna W.; Reyes, Anny; Devidze, Nino; Phan, Anna; Pfaff, Donald W.; Choleris, Elena

    2012-01-01

    Inter- and intra-species differences in social behavior and recognition-related hormones and receptors suggest that different distribution and/or expression patterns may relate to social recognition. We used qRT-PCR to investigate naturally occurring differences in expression of estrogen receptor-alpha (ERα), ER-beta (ERβ), progesterone receptor (PR), oxytocin (OT) and receptor, and vasopressin (AVP) and receptors in proestrous female mice. Following four 5 min exposures to the same two conspecifics, one was replaced with a novel mouse in the final trial (T5). Gene expression was examined in mice showing high (85–100%) and low (40–60%) social recognition scores (i.e., preferential novel mouse investigation in T5) in eight socially-relevant brain regions. Results supported OT and AVP involvement in social recognition, and suggest that in the medial preoptic area, increased OT and AVP mRNA, together with ERα and ERβ gene activation, relate to improved social recognition. Initial social investigation correlated with ERs, PR and OTR in the dorsolateral septum, suggesting that these receptors may modulate social interest without affecting social recognition. Finally, increased lateral amygdala gene activation in the LR mice may be associated with general learning impairments, while decreased lateral amygdala activity may indicate more efficient cognitive mechanisms in the HR mice. PMID:22079582

  19. Relaxant Effects of the Selective Estrogen Receptor Modulator, Bazedoxifene, and Estrogen Receptor Agonists in Isolated Rabbit Basilar Artery.

    PubMed

    Castelló-Ruiz, María; Salom, Juan B; Fernández-Musoles, Ricardo; Burguete, María C; López-Morales, Mikahela A; Arduini, Alessandro; Jover-Mengual, Teresa; Hervás, David; Torregrosa, Germán; Alborch, Enrique

    2016-10-01

    We have previously shown that the selective estrogen receptor modulator, bazedoxifene, improves the consequences of ischemic stroke. Now we aimed to characterize the effects and mechanisms of action of bazedoxifene in cerebral arteries. Male rabbit isolated basilar arteries were used for isometric tension recording and quantitative polymerase chain reaction. Bazedoxifene relaxed cerebral arteries, as 17-β-estradiol, 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol [estrogen receptor (ER) α agonist], and G1 [G protein-coupled ER (GPER) agonist] did it (4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol > bazedoxifene = G1 > 17-β-estradiol). 2,3-Bis(4-hydroxyphenyl)-propionitrile (ERβ agonist) had no effect. Expression profile of genes encoding for ERα (ESR1), ERβ (ESR2), and GPER was GPER > ESR1 > ESR2. As to the endothelial mechanisms, endothelium removal, N-nitro-L-arginine methyl ester, and indomethacin, did not modify the relaxant responses to bazedoxifene. As to the K channels, both a high-K medium and the Kv blocker, 4-aminopyridine, inhibited the bazedoxifene-induced relaxations, whereas tetraethylammonium (nonselective K channel blocker), glibenclamide (selective KATP blocker) or iberiotoxin (selective KCa blocker) were without effect. Bazedoxifene also inhibited both Ca- and Bay K8644-elicited contractions. Therefore, bazedoxifene induces endothelium-independent relaxations of cerebral arteries through (1) activation of GPER and ERα receptors; (2) increase of K conductance through Kv channels; and (3) inhibition of Ca entry through L-type Ca channels. Such a profile is compatible with the beneficial effects of estrogenic compounds (eg, SERMs) on vascular function and, specifically, that concerning the brain. Therefore, bazedoxifene could be useful in the treatment of cerebral disorders in which the cerebrovascular function is compromised (eg, stroke).

  20. Bridging hypoxia, inflammation and estrogen receptors in thyroid cancer progression.

    PubMed

    Tafani, Marco; De Santis, Elena; Coppola, Luigi; Perrone, Giulietta A; Carnevale, Ilaria; Russo, Andrea; Pucci, Bruna; Carpi, Angelo; Bizzarri, Mariano; Russo, Matteo A

    2014-02-01

    Thyroid cancer is a common endocrine-related cancer with a higher incidence in women than in men. Thyroid tumors are classified on the basis of their histopathology as papillary, follicular, medullary, and undifferentiated or anaplastic. Epidemiological and in vitro or in vivo studies have suggested a correlation between incidence of thyroid malignancies and hormones. In particular, growing evidence indicates a role of estrogens and estrogen receptors (ERs) in thyroid tumorigenesis, reprogramming and progression. In this scenario, estrogens are hypothesized to contribute to the observed female predominance of thyroid cancer in reproductive years. However, the precise contribution of estrogens in thyroid proliferative disease initiation and progression is not well understood. HIF-1α and NF-κB are two transcription factors very frequently activated in tumors and involved in tumor growth, progression and resistance to chemotherapy. In fact, HIF-1α and NF-κB together regulate transcription of over a thousand genes that, in turn, control vital cellular processes such as adaptation to the hypoxia, metabolic and differentiation reprogramming, inflammatory-reparative response, extracellular matrix digestion, migration and invasion, adhesion, etc. Because of this wide involvement, they could control in an integrated manner the origin of the malignant phenotype. Interestingly, hypoxia and inflammation have been sequentially bridged in tumors by the discovery that alarmin receptors genes such as RAGE, P2X7 and some TLRs are activated by HIF-1α; and that, in turn, alarmin receptors strongly activate NF-κB and proinflammatory gene expression, evidencing all the hallmarks of the malignant phenotype. Recently, a large number of drugs have been identified that inhibit one or both transcription factors with promising results in terms of controlling tumor progression. In addition, many of these inhibitors are natural compounds or off-label drugs already used to cure other

  1. Quantitative structure-activity relationships (QSARs) for estrogen binding to the estrogen receptor: predictions across species.

    PubMed Central

    Tong, W; Perkins, R; Strelitz, R; Collantes, E R; Keenan, S; Welsh, W J; Branham, W S; Sheehan, D M

    1997-01-01

    The recognition of adverse effects due to environmental endocrine disruptors in humans and wildlife has focused attention on the need for predictive tools to select the most likely estrogenic chemicals from a very large number of chemicals for subsequent screening and/or testing for potential environmental toxicity. A three-dimensional quantitative structure-activity relationship (QSAR) model using comparative molecular field analysis (CoMFA) was constructed based on relative binding affinity (RBA) data from an estrogen receptor (ER) binding assay using calf uterine cytosol. The model demonstrated significant correlation of the calculated steric and electrostatic fields with RBA and yielded predictions that agreed well with experimental values over the entire range of RBA values. Analysis of the CoMFA three-dimensional contour plots revealed a consistent picture of the structural features that are largely responsible for the observed variations in RBA. Importantly, we established a correlation between the predicted RBA values for calf ER and their actual RBA values for human ER. These findings suggest a means to begin to construct a more comprehensive estrogen knowledge base by combining RBA assay data from multiple species in 3D-QSAR based predictive models, which could then be used to screen untested chemicals for their potential to bind to the ER. Another QSAR model was developed based on classical physicochemical descriptors generated using the CODESSA (Comprehensive Descriptors for Structural and Statistical Analysis) program. The predictive ability of the CoMFA model was superior to the corresponding CODESSA model. Images Figure 2. Figure 3. Figure 4. Figure 5. PMID:9353176

  2. Whole-genome cartography of estrogen receptor alpha binding sites.

    PubMed

    Lin, Chin-Yo; Vega, Vinsensius B; Thomsen, Jane S; Zhang, Tao; Kong, Say Li; Xie, Min; Chiu, Kuo Ping; Lipovich, Leonard; Barnett, Daniel H; Stossi, Fabio; Yeo, Ailing; George, Joshy; Kuznetsov, Vladimir A; Lee, Yew Kok; Charn, Tze Howe; Palanisamy, Nallasivam; Miller, Lance D; Cheung, Edwin; Katzenellenbogen, Benita S; Ruan, Yijun; Bourque, Guillaume; Wei, Chia-Lin; Liu, Edison T

    2007-06-01

    Using a chromatin immunoprecipitation-paired end diTag cloning and sequencing strategy, we mapped estrogen receptor alpha (ERalpha) binding sites in MCF-7 breast cancer cells. We identified 1,234 high confidence binding clusters of which 94% are projected to be bona fide ERalpha binding regions. Only 5% of the mapped estrogen receptor binding sites are located within 5 kb upstream of the transcriptional start sites of adjacent genes, regions containing the proximal promoters, whereas vast majority of the sites are mapped to intronic or distal locations (>5 kb from 5' and 3' ends of adjacent transcript), suggesting transcriptional regulatory mechanisms over significant physical distances. Of all the identified sites, 71% harbored putative full estrogen response elements (EREs), 25% bore ERE half sites, and only 4% had no recognizable ERE sequences. Genes in the vicinity of ERalpha binding sites were enriched for regulation by estradiol in MCF-7 cells, and their expression profiles in patient samples segregate ERalpha-positive from ERalpha-negative breast tumors. The expression dynamics of the genes adjacent to ERalpha binding sites suggest a direct induction of gene expression through binding to ERE-like sequences, whereas transcriptional repression by ERalpha appears to be through indirect mechanisms. Our analysis also indicates a number of candidate transcription factor binding sites adjacent to occupied EREs at frequencies much greater than by chance, including the previously reported FOXA1 sites, and demonstrate the potential involvement of one such putative adjacent factor, Sp1, in the global regulation of ERalpha target genes. Unexpectedly, we found that only 22%-24% of the bona fide human ERalpha binding sites were overlapping conserved regions in whole genome vertebrate alignments, which suggest limited conservation of functional binding sites. Taken together, this genome-scale analysis suggests complex but definable rules governing ERalpha binding and gene

  3. The effect of low-dose experimental zearalenone intoxication on the immunoexpression of estrogen receptors in the ovaries of pre-pubertal bitches.

    PubMed

    Gajecka, M

    2012-01-01

    Zearalenone is an estrogenic mycotoxin that often contaminates plant material used in the production of feeds for companion animals. Small daily doses of ingested zearalenone--a competitive substrate modulating the activity of enzymes participating in estrogen biosynthesis at the pre-receptor level--can induce subclinical symptoms of hyperestrogenism in bitches. The objective of this study was to determine the effects of low zearalenone doses on the presence of estrogen receptors in the ovaries of pre-pubertal Beagle bitches. The bitches were divided into three groups of 10 animals each: experimental group I--50 microg zearalenone/kg body weight administered once daily per os; experimental group II--75 microg zearalenone/kg body weight administered once daily per os; control group--placebo containing no ZEN administered per os. The animals were ovariorectomized at the end of the experiment, at 112 days of age. Estrogen receptors were detected in ovarian specimens by immunohistochemical methods. The results revealed an absence of estrogen receptors alpha in all groups. In both experimental groups a decrease in the positive response of estrogen receptors beta in specified structures of ovaries was observed. Very low alpha-zearalenol levels probably attested to the slowing down (hypostimulation) of the biotransformation process. Overall, zearalenone intoxication led to hyperestrogenism during a specific developmental stage of pre-pubertal bitches. As regards hormesis, the threshold dose of zearalenone (adaptive capability) was exceeded in the ovaries of experimental group II animals. The results obtained in both experimental groups suggest that long-term exposure to low-dose zearalenone intoxication decreased the degree of estrogen receptors beta staining in particular structures of ovaries in the experimental bitches, which initiated epigenetic modification mechanisms that inhibited ovarian development.

  4. Modulation of the ligand-independent activation of the human estrogen receptor by hormone and antihormone.

    PubMed Central

    Smith, C L; Conneely, O M; O'Malley, B W

    1993-01-01

    It has been previously demonstrated that several members of the steroid receptor superfamily may be activated by the neurotransmitter dopamine in the apparent absence of cognate ligand. We have examined wild-type and mutant human estrogen receptors (ERs, [Gly400]ER and [Val400]ER, respectively) for their abilities to activate ER-dependent transcription of a transgene in a ligand-independent manner. In cells expressing the wild-type ER, dopamine was nearly as effective as 17 beta-estradiol at inducing the chloramphenicol acetyltransferase activity of the reporter gene in a dose-dependent manner; simultaneous addition of suboptimal concentrations of 17 beta-estradiol and dopamine stimulated transcription more than either compound alone. Dopamine alone was unable to induce gene expression in cells expressing [Val400]ER mutant receptors, but concomitant treatment with 17 beta-estradiol produced a synergistic increase in transcription, suggesting that the ligand may alter the mutant receptor's conformation such that it can be activated subsequently by a dopaminergic signaling mechanism. In the presence of the antiestrogen ICI 164,384, dopamine-stimulated gene expression was undetectable in cells expressing either form of ER. However, simultaneous treatment of cells expressing wild-type ER with trans-4-hydroxytamoxifen and dopamine resulted in transgene expression that was additive in nature compared to either compound alone; similar treatment of cells expressing [Val400]ER produced a synergistic increase. Our results suggest that ligand and ligand-independent activation of the ER initiate from distinct pathways and that the latter may occur in a variety of target tissues subject to modulation by receptor ligands. Images Fig. 5 PMID:8327492

  5. Estrogenic effects from household stoves.

    PubMed

    Wu, W Z; Chen, J; Rehmann, K; Schramm, K W; Kettrup

    2002-09-01

    With the application of a genetically modified yeast, estrogen receptor-activating compounds were detected in the soot and emission gas of a wood-burning household stove. The EC50 value of 17beta-estradiol was divided by the EC50 value of soot, and the obtained relative estrogenic value for raw soot was 2.37E-5, indicating that soot was about 100,000 times less estrogenic than 17beta-estradiol. Chemical analysis revealed that alkyl phenol, benzonic acid, and PAHs represented the major constituents in the most potent fractions of the soot. Along with PAHs, other constituents might also contribute to the estrogenicity of soot.

  6. Estrogen receptor-alpha mediates estrogen protection from angiotensin II-induced hypertension in conscious female mice.

    PubMed

    Xue, Baojian; Pamidimukkala, Jaya; Lubahn, Dennis B; Hay, Meredith

    2007-04-01

    It has been shown that the female sex hormones have a protective role in the development of angiotensin II (ANG II)-induced hypertension. The present study tested the hypotheses that 1) the estrogen receptor-alpha (ERalpha) is involved in the protective effects of estrogen against ANG II-induced hypertension and 2) central ERs are involved. Blood pressure (BP) was measured in female mice with the use of telemetry implants. ANG II (800 ng.kg(-1).min(-1)) was administered subcutaneously via an osmotic pump. Baseline BP in the intact, ovariectomized (OVX) wild-type (WT) and ERalpha knockout (ERalphaKO) mice was similar; however, the increase in BP induced by ANG II was greater in OVX WT (23.0 +/- 1.0 mmHg) and ERalphaKO mice (23.8 +/- 2.5 mmHg) than in intact WT mice (10.1 +/- 4.5 mmHg). In OVX WT mice, central infusion of 17beta-estradiol (E(2); 30 microg.kg(-1).day(-1)) attenuated the pressor effect of ANG II (7.0 +/- 0.4 mmHg), and this protective effect of E(2) was prevented by coadministration of ICI-182,780 (ICI; 1.5 microg.kg(-1).day(-1), 18.8 +/- 1.5 mmHg), a nonselective ER antagonist. Furthermore, central, but not peripheral, infusions of ICI augmented the pressor effects of ANG II in intact WT mice (17.8 +/- 4.2 mmHg). In contrast, the pressor effect of ANG II was unchanged in either central E(2)-treated OVX ERalphaKO mice (19.0 +/- 1.1 mmHg) or central ICI-treated intact ERalphaKO mice (19.6 +/- 1.6 mmHg). Lastly, ganglionic blockade on day 7 after ANG II infusions resulted in a greater reduction in BP in OVX WT, central ER antagonist-treated intact WT, central E(2) + ICI-treated OVX WT, ERalphaKO, and central E(2)- or ICI-treated ERalphaKO mice compared with that in intact WT mice given just ANG II. Together, these data indicate that ERalpha, especially central expression of the ER, mediates the protective effects of estrogen against ANG II-induced hypertension.

  7. Homeobox A7 stimulates breast cancer cell proliferation by up-regulating estrogen receptor-alpha

    SciTech Connect

    Zhang, Yu; Cheng, Jung-Chien; Huang, He-Feng; Leung, Peter C.K.

    2013-11-01

    Highlights: •HOXA7 regulates MCF7 cell proliferation. •HOXA7 up-regulates ERα expression. •HOXA7 mediates estrogen-induced MCF7 cell proliferation. -- Abstract: Breast cancer is the most common hormone-dependent malignancy in women. Homeobox (HOX) transcription factors regulate many cellular functions, including cell migration, proliferation and differentiation. The aberrant expression of HOX genes has been reported to be associated with human reproductive cancers. Estradiol (E2) and its nuclear receptors, estrogen receptor (ER)-alpha and ER-beta, are known to play critical roles in the regulation of breast cancer cell growth. However, an understanding of the potential relationship between HOXA7 and ER in breast cancer cells is limited. In this study, our results demonstrate that knockdown of HOXA7 in MCF7 cells significantly decreased cell proliferation and ERα expression. In addition, HOXA7 knockdown attenuated E2-induced cell proliferation as well as progesterone receptor (PR) expression. The stimulatory effects of E2 on cell proliferation and PR expression were abolished by co-treatment with ICI 182780, a selective ERα antagonist. In contrast, overexpression of HOXA7 significantly stimulated cell proliferation and ERα expression. Moreover, E2-induced cell proliferation, as well as PR expression, was enhanced by the overexpression of HOXA7. Neither knockdown nor overexpression of HOXA7 affected the ER-beta levels. Our results demonstrate a novel mechanistic role for HOXA7 in modulating breast cancer cell proliferation via regulation of ERα expression. This finding contributes to our understanding of the role HOXA7 plays in regulating the proliferation of ER-positive cancer cells.

  8. 3-Methylcholanthrene and other aryl hydrocarbon receptor agonists directly activate estrogen receptor alpha.

    PubMed

    Abdelrahim, Maen; Ariazi, Eric; Kim, Kyounghyun; Khan, Shaheen; Barhoumi, Rola; Burghardt, Robert; Liu, Shengxi; Hill, Denise; Finnell, Richard; Wlodarczyk, Bogdan; Jordan, V Craig; Safe, Stephen

    2006-02-15

    3-Methylcholanthrene (3MC) is an aryl hydrocarbon receptor (AhR) agonist, and it has been reported that 3MC induces estrogenic activity through AhR-estrogen receptor alpha (ER alpha) interactions. In this study, we used 3MC and 3,3',4,4',5-pentachlorobiphenyl (PCB) as prototypical AhR ligands, and both compounds activated estrogen-responsive reporter genes/gene products (cathepsin D) in MCF-7 breast cancer cells. The estrogenic responses induced by these AhR ligands were inhibited by the antiestrogen ICI 182780 and by the transfection of a small inhibitory RNA for ER alpha but were not affected by the small inhibitory RNA for AhR. These results suggest that 3MC and PCB directly activate ER alpha, and this was confirmed in a competitive ER alpha binding assay and in a fluorescence resonance energy transfer experiment in which PCB and 3MC induced CFP-ER alpha/YFP-ER alpha interactions. In a chromatin immunoprecipitation assay, PCB and 3MC enhanced ER alpha (but not AhR) association with the estrogen-responsive region of the pS2 gene promoter. Moreover, in AhR knockout mice, 3MC increased uterine weights and induced expression of cyclin D1 mRNA levels. These results show that PCB and 3MC directly activate ER alpha-dependent transactivation and extend the number of ligands that activate both AhR and ER alpha.

  9. Estrogen receptor alpha single nucleotide polymorphism as predictor of diabetes type 2 risk in hypogonadal men.

    PubMed

    Linnér, Carl; Svartberg, Johan; Giwercman, Aleksander; Giwercman, Yvonne Lundberg

    2013-06-01

    Estradiol (E2) is, apart from its role as a reproductive hormone, also important for cardiac function and bone maturation in both genders. It has also been shown to play a role in insulin production, energy expenditure and in inducing lipolysis. The aim of the study was to investigate if low circulating testosterone or E2 levels in combination with variants in the estrogen receptor alpha (ESR1) and estrogen receptor beta (ESR2) genes were of importance for the risk of type-2 diabetes. The single nucleotide polymorphisms rs2207396 and rs1256049, in ESR1 and ESR2, respectively, were analysed by allele specific PCR in 172 elderly men from the population-based Tromsø study. The results were adjusted for age. In individuals with low total (≤11 nmol/L) or free testosterone (≤0.18 nmol/L) being carriers of the variant A-allele in ESR1 was associated with 7.3 and 15.9 times, respectively, increased odds ratio of being diagnosed with diabetes mellitus type 2 (p = 0.025 and p = 0.018, respectively). Lower concentrations of E2 did not seem to increase the risk of being diagnosed with diabetes. In conclusion, in hypogonadal men, the rs2207396 variant in ESR1 predicts the risk of type 2 diabetes.

  10. Estrogen-related receptor alpha modulates the expression of adipogenesis-related genes during adipocyte differentiation.

    PubMed

    Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Yagi, Ken; Okazaki, Yasushi; Inoue, Satoshi

    2007-07-06

    Estrogen-related receptor alpha (ERRalpha) is an orphan nuclear receptor that regulates cellular energy metabolism by modulating gene expression involved in fatty acid oxidation and mitochondrial biogenesis in brown adipose tissue. However, the physiological role of ERRalpha in adipogenesis and white adipose tissue development has not been well studied. Here, we show that ERRalpha and ERRalpha-related transcriptional coactivators, peroxisome proliferator-activated receptor gamma (PPARgamma) coactivator-1alpha (PGC-1alpha) and PGC-1beta, can be up-regulated in 3T3-L1 preadipocytes at mRNA levels under the adipogenic differentiation condition including the inducer of cAMP, glucocorticoid, and insulin. Gene knockdown by ERRalpha-specific siRNA results in mRNA down-regulation of fatty acid binding protein 4, PPARgamma, and PGC-1alpha in 3T3-L1 cells in the adipogenesis medium. ERRalpha and PGC-1beta mRNA expression can be also up-regulated in another preadipocyte lineage DFAT-D1 cells and a pluripotent mesenchymal cell line C3H10T1/2 under the differentiation condition. Furthermore, stable expression of ERRalpha in 3T3-L1 cells up-regulates adipogenic marker genes and promotes triglyceride accumulation during 3T3-L1 differentiation. These results suggest that ERRalpha may play a critical role in adipocyte differentiation by modulating the expression of various adipogenesis-related genes.

  11. Exploring the Contribution of Estrogen to Amyloid-Beta Regulation: A Novel Multifactorial Computational Modeling Approach

    PubMed Central

    Anastasio, Thomas J.

    2013-01-01

    According to the amyloid hypothesis, Alzheimer Disease results from the accumulation beyond normative levels of the peptide amyloid-β (Aβ). Perhaps because of its pathological potential, Aβ and the enzymes that produce it are heavily regulated by the molecular interactions occurring within cells, including neurons. This regulation involves a highly complex system of intertwined normative and pathological processes, and the sex hormone estrogen contributes to it by influencing the Aβ-regulation system at many different points. Owing to its high complexity, Aβ regulation and the contribution of estrogen are very difficult to reason about. This report describes a computational model of the contribution of estrogen to Aβ regulation that provides new insights and generates experimentally testable and therapeutically relevant predictions. The computational model is written in the declarative programming language known as Maude, which allows not only simulation but also analysis of the system using temporal-logic. The model illustrates how the various effects of estrogen could work together to reduce Aβ levels, or prevent them from rising, in the presence of pathological triggers. The model predicts that estrogen itself should be more effective in reducing Aβ than agonists of estrogen receptor α (ERα), and that agonists of ERβ should be ineffective. The model shows how estrogen itself could dramatically reduce Aβ, and predicts that non-steroidal anti-inflammatory drugs should provide a small additional benefit. It also predicts that certain compounds, but not others, could augment the reduction in Aβ due to estrogen. The model is intended as a starting point for a computational/experimental interaction in which model predictions are tested experimentally, the results are used to confirm, correct, and expand the model, new predictions are generated, and the process continues, producing a model of ever increasing explanatory power and predictive value. PMID

  12. Effects of gamma irradiation on the DNA-protein complex between the estrogen response element and the estrogen receptor

    NASA Astrophysics Data System (ADS)

    Štísová, Viktorie; Goffinont, Stephane; Spotheim-Maurizot, Melanie; Davídková, Marie

    2010-08-01

    Signaling by estrogens, risk factors in breast cancer, is mediated through their binding to the estrogen receptor protein (ER), followed by the formation of a complex between ER and a DNA sequence, called estrogen response element (ERE). Anti-estrogens act as competitive inhibitors by blocking the signal transduction. We have studied in vitro the radiosensitivity of the complex between ERα, a subtype of this receptor, and a DNA fragment bearing ERE, as well as the influence of an estrogen (estradiol) or an anti-estrogen (tamoxifen) on this radiosensitivity. We observe that the complex is destabilized upon irradiation with γ rays in aerated aqueous solution. The analysis of the decrease of binding abilities of the two partners shows that destabilization is mainly due to the damage to the protein. The destabilization is reduced when irradiating in presence of tamoxifen and is increased in presence of estradiol. These effects are due to opposite influences of the ligands on the loss of binding ability of ER. The mechanism that can account for our results is: binding of estradiol or tamoxifen induces distinct structural changes of the ER ligand-binding domain that can trigger (by allostery) distinct structural changes of the ER DNA-binding domains and thus, can differently affect ER-ERE interaction.

  13. Modulation of mitochondrial Ca(2+) uptake by estrogen receptor agonists and antagonists.

    PubMed

    Lobatón, Carmen D; Vay, Laura; Hernández-Sanmiguel, Esther; Santodomingo, Jaime; Moreno, Alfredo; Montero, Mayte; Alvarez, Javier

    2005-08-01

    Ca(2+) uptake by mitochondria is a key element in the control of cellular Ca(2+) homeostasis and Ca(2+)-dependent phenomena. It has been known for many years that this Ca(2+) uptake is mediated by the mitochondrial Ca(2+) uniporter, a specific Ca(2+) channel of the inner mitochondrial membrane. We have shown previously that this channel is strongly activated by a series of natural phytoestrogenic flavonoids. We show here that several agonists and antagonists of estrogen receptors (ERs) also modulate the activity of the uniporter. The specific alpha-ER agonist 4,4',4''-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT) was the strongest activator, increasing the rate of mitochondrial Ca(2+) uptake in permeabilized HeLa cells by 10-fold at 2 microM. Consistently, PPT largely increased the histamine-induced mitochondrial [Ca(2+)] peak and reduced the cytosolic one. Diethylstilbestrol and 17-beta-estradiol (but not 17-alpha-estradiol) were active at pharmacological concentrations while the beta-estrogen-receptor agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) was little effective. The ER modulators tamoxifen and 4-hydroxy-tamoxifen inhibited mitochondrial Ca(2+) uptake (IC(50) 2.5+/-1.5 and 2.5+/-1.4 microM, mean+/-s.d., respectively) both in the presence and in the absence of PPT, but raloxifene and the pure estrogen antagonist ICI 182,780 produced no effect. Activation by PPT was immediate and inhibition by tamoxifen or 4-hydroxy-tamoxifen required only 5 min to reach maximum. Tamoxifen did not modify mitochondrial membrane potential and PPT induced a slow mitochondrial depolarization at higher concentrations than those required to activate mitochondrial Ca(2+) uptake. These results suggest that some kind of ER or related protein located in mitochondria controls the activity of the Ca(2+) uniporter by a nongenomic mechanism. This novel mechanism of action of estrogen agonists and antagonists can provide a new interpretation for several previously reported

  14. Contribution of a membrane estrogen receptor to the estrogenic regulation of body temperature and energy homeostasis.

    PubMed

    Roepke, Troy A; Bosch, Martha A; Rick, Elizabeth A; Lee, Benjamin; Wagner, Edward J; Seidlova-Wuttke, Dana; Wuttke, Wolfgang; Scanlan, Thomas S; Rønnekleiv, Oline K; Kelly, Martin J

    2010-10-01

    The hypothalamus is a key region of the central nervous system involved in the control of homeostasis, including energy and core body temperature (Tc). 17β-Estradiol (E2) regulates Tc, in part, via actions in the basal hypothalamus and preoptic area. E2 primarily controls hypothalamic functions via the nuclear steroid receptors, estrogen receptor α/β. However, we have previously described an E2-responsive, Gq-coupled membrane receptor that reduces the postsynaptic inhibitory γ-aminobutyric acid-ergic tone and attenuates postovariectomy body weight gain in female guinea pigs through the administration of a selective Gq-mER ligand, STX. To determine the role of Gq-mER in regulating Tc, energy and bone homeostasis, ovariectomized female guinea pigs, implanted ip with temperature probes, were treated with STX or E2 for 7-8 wk. Tc was recorded for 4 wk, whereas food intake and body weight were monitored daily. Bone density and fat accumulation were determined postmortem. Both E2 and STX significantly reduced Tc in the females compared with controls. STX, similar to E2, reduced food intake and fat accumulation and increased tibial bone density. Therefore, a Gq-mER-coupled signaling pathway appears to be involved in maintaining homeostatic functions and may constitute a novel therapeutic target for treatment of hypoestrogenic symptoms.

  15. Contribution of a Membrane Estrogen Receptor to the Estrogenic Regulation of Body Temperature and Energy Homeostasis

    PubMed Central

    Roepke, Troy A.; Bosch, Martha A.; Rick, Elizabeth A.; Lee, Benjamin; Wagner, Edward J.; Seidlova-Wuttke, Dana; Wuttke, Wolfgang; Scanlan, Thomas S.; Rønnekleiv, Oline K.; Kelly, Martin J.

    2010-01-01

    The hypothalamus is a key region of the central nervous system involved in the control of homeostasis, including energy and core body temperature (Tc). 17β-Estradiol (E2) regulates Tc, in part, via actions in the basal hypothalamus and preoptic area. E2 primarily controls hypothalamic functions via the nuclear steroid receptors, estrogen receptor α/β. However, we have previously described an E2-responsive, Gq-coupled membrane receptor that reduces the postsynaptic inhibitory γ-aminobutyric acid-ergic tone and attenuates postovariectomy body weight gain in female guinea pigs through the administration of a selective Gq-mER ligand, STX. To determine the role of Gq-mER in regulating Tc, energy and bone homeostasis, ovariectomized female guinea pigs, implanted ip with temperature probes, were treated with STX or E2 for 7–8 wk. Tc was recorded for 4 wk, whereas food intake and body weight were monitored daily. Bone density and fat accumulation were determined postmortem. Both E2 and STX significantly reduced Tc in the females compared with controls. STX, similar to E2, reduced food intake and fat accumulation and increased tibial bone density. Therefore, a Gq-mER-coupled signaling pathway appears to be involved in maintaining homeostatic functions and may constitute a novel therapeutic target for treatment of hypoestrogenic symptoms. PMID:20685867

  16. Tamoxifen Dependent Interaction Between the Estrogen Receptor and a Novel P21 Activated Kinase

    DTIC Science & Technology

    2002-06-01

    AD Award Number: DAMDl7-01-1-0149 TITLE: Tamoxifen Dependent Interaction Between the Estrogen Receptor and a Novel P21 Activated Kinase PRINCIPAL...Tamoxifen Dependent Interaction Between the DAMD17-00-1-0114 Estrogen Receptor and a Novel P21 Activated Kinase 6. AUTHOR(S) Steven P. Balk, M.D., Ph.D. 7...Z, Karas RH, nisms of androgen receptor activation and function. J Mendelsohn ME, Shaul PW 1999 Estrogen receptor a Steroid Biochem Mol Biol 69:307

  17. Histone methylase MLL1 and MLL3 coordinate with estrogen receptors in estrogen-mediated HOXB9 expression

    PubMed Central

    Ansari, Khairul I.; Shrestha, Bishakha; Hussain, Imran; Kasiri, Sahba; Mandal, Subhrangsu S.

    2011-01-01

    Homeobox gene HOXB9 is a critical player in development of mammary gland and sternum and in regulation of Renin which is closely linked with blood pressure control. Our studies demonstrated that HOXB9 gene is transcriptionally regulated by estrogen (E2). HOXB9 promoter contains several estrogen-response elements (ERE). Reporter assay based experiments demonstrated that HOXB9 promoter EREs are estrogen-responsive. Estrogen receptors ERα and ERβ are essential for E2-mediated transcriptional activation of HOXB9. Chromatin immuno-precipitation assay demonstrated that ERs bind to HOXB9 EREs as a function of E2. Similarly, histone methylases MLL1 and MLL3 also bind to HOXB9 EREs and play critical role in E2-mediated transcriptional activation of HOXB9. Overall, our studies demonstrated that HOXB9 is an E2-responsive gene and ERs coordinate with MLL1 and MLL3 in E2-mediated transcriptional regulation of HOXB9. PMID:21428455

  18. Icariin exerts estrogen-like activity in ameliorating EAE via mediating estrogen receptor β, modulating HPA function and glucocorticoid receptor expression

    PubMed Central

    Wei, Zhisheng; Wang, Mengxia; Hong, Mingfan; Diao, Shengpeng; Liu, Aiqun; Huang, Yeqing; Yu, Qingyun; Peng, Zhongxing

    2016-01-01

    Background: Estrogen exerts neuroprotective and anti-inflammatory effects in EAE and multiple sclerosis (MS), but its clinical application is hindered due to side effects and risk of tumor. Phytoestrogen structurally or functionally mimics estrogen with fewer side effects than endogenous estrogen. Icariin (ICA), an active component of Epimedium extracts, demonstrates estrogen-like neuroprotective effects. However, it is unclear whether ICA is effective in EAE and what are the underlying mechanisms. Objective: To determine the therapeutic effects of ICA in EAE and explore the possible mechanisms. Methods: C57BL/6 EAE mice were treated with Diethylstilbestrol, different dose of ICA and mid-dose ICA combined with ICI 182780. The clinical scores and serum Interleukin-17 (IL-17), Corticosterone (CORT) concentrations were then analyzed. Western blot were performed to investigate the expressions of glucocorticoid receptor (GR), estrogen receptor alpha (ERα) and ERβ in the cerebral white matter of EAE mice. Results: High dose ICA is equally effective in ameliorating neurological signs of EAE as estrogen. Estrogen and ICA has no effects on serum concentrations of IL-17 in EAE. While the CORT levels were decreased by ICA at mid or high doses, the expressions of GR, ERα and ERβ were up-regulated by estrogen or different doses of ICA in a dosedependent manner. Estrogen induced the elevation of ERα more markedly than ICA. In contrast, ICA at mid and high doses promoted ERβ more significantly than estrogen. Conclusion: ICA exerts estrogen-like activity in ameliorating EAE via mediating ERβ, modulating HPA function and up-regulating the expression of GR in cerebral white matter. ICA may be a promising therapeutic option for MS. PMID:27186315

  19. Bisphenol A and Related Alkylphenols Exert Nongenomic Estrogenic Actions Through a G Protein-Coupled Estrogen Receptor 1 (Gper)/Epidermal Growth Factor Receptor (Egfr) Pathway to Inhibit Meiotic Maturation of Zebrafish Oocytes1

    PubMed Central

    Fitzgerald, Amanda C.; Peyton, Candace; Dong, Jing; Thomas, Peter

    2015-01-01

    Xenobiotic estrogens, such as bisphenol A (BPA), disrupt a wide variety of genomic estrogen actions, but their nongenomic estrogen actions remain poorly understood. We investigated nongenomic estrogenic effects of low concentrations of BPA and three related alkylphenols on the inhibition of zebrafish oocye maturation (OM) mediated through a G protein-coupled estrogen receptor 1 (Gper)-dependent epidermal growth factor receptor (Egfr) pathway. BPA (10–100 nM) treatment for 3 h mimicked the effects of estradiol-17beta (E2) and EGF, decreasing spontaneous maturation of defolliculated zebrafish oocytes, an effect not blocked by coincubation with actinomycin D, but blocked by coincubation with a Gper antibody. BPA displayed relatively high binding affinity (15.8% that of E2) for recombinant zebrafish Gper. The inhibitory effects of BPA were attenuated by inhibition of upstream regulators of Egfr, intracellular tyrosine kinase (Src) with PP2, and matrix metalloproteinase with ilomastat. Treatment with an inhibitor of Egfr transactivation, AG1478, and an inhibitor of the mitogen-activated protein kinase (MAPK) 3/1 pathway, U0126, increased spontaneous OM and blocked the inhibitory effects of BPA, E2, and the selective GPER agonist, G-1. Western blot analysis showed that BPA (10–200 nM) mimicked the stimulatory effects of E2 and EGF on Mapk3/1 phosphorylation. Tetrabromobisphenol A, 4-nonylphenol, and tetrachlorobisphenol A (5–100 nM) also inhibited OM, an effect blocked by cotreatment with AG1478, as well as with the GPER antagonist, G-15, and displayed similar binding affinities as BPA to zebrafish Gper. The results suggest that BPA and related alkylphenols disrupt zebrafish OM by a novel nongenomic estrogenic mechanism involving activation of the Gper/Egfr/Mapk3/1 pathway. PMID:26490843

  20. Impact of Apparent Antagonism of Estrogen Receptor β by Fulvestrant on Anticancer Activity of 2-Methoxyestradiol.

    PubMed

    Gorska, Magdalena; Wyszkowska, Roksana Maja; Kuban-Jankowska, Alicja; Wozniak, Michal

    2016-05-01

    Osteosarcoma is one of the most malignant bone tumors of childhood and adolescence. Interestingly, the presence of estrogen receptors α and β has been reported in human bone cells, including osteosarcoma. Thus, inhibitors of estrogens such as fulvestrant, are considered candidates for novel endocrine therapy in treatment of osteosarcoma. Another anticancer agent that seems to be very effective in treatment of osteosarcoma is a derivative of 17β-estradiol, 2-methoxyestradiol. The aim of this study was to determine the anticancer activities of pure anti-estrogen, fulvestrant and combined treatment of fulvestrant and 2-methoxyestradiol towards highly metastatic osteosarcoma 143B cells. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay was used in order to determine the antiproliferative potential of the compounds, and western blotting for estrogen receptors α and β. Flow cytometry was used in order to determine induction of cell death, cell-cycle arrest, mitochondrial depolarization, and DNA damage. Herein, we showed that fulvestrant has anticancer activity only at high concentrations. We were able to find and expression of estrogen receptor β, while we did not detect estrogen receptor α in osteosarcoma 143B cells. Moreover, fulvestrant down-regulated the expression of estrogen receptor β, and this effect was reversed by 2-methoxyestradiol. Thus, the obtained data suggest that 2-methoxyestradiol may exert part of its anticancer activity through modulation of expression of estrogen receptor β.

  1. Commonly occurring plant flavonoids have estrogenic activity.

    PubMed

    Miksicek, R J

    1993-07-01

    A remarkable diversity of naturally occurring and synthetic compounds have been shown to mimic the biological effects of 17 beta-estradiol by virtue of their ability to bind to and activate the nuclear estrogen receptor. This report extends the family of nonsteroidal estrogens to include several multiply hydroxylated chalcones, flavanones, and flavones. The hormone-like activity of these natural plant products is indicated by their ability to stimulate an estrogen receptor-dependent transcriptional response and to promote growth of estrogen-dependent MCF7 cells in culture. The transcriptional response can be inhibited by the steroidal estrogen antagonist ICI-164,384 and is specific for the estrogen receptor. Evidence is presented to show that selected hydroxylated flavonoids interact directly with the estrogen receptor, based on their ability to compete for the binding of 17 beta-[3H]estradiol to the receptor in cell-free extracts. These compounds are less active, on a molar basis, than 17 beta-estradiol or the synthetic dihydroxystilbene estrogens, but they have potencies comparable to those of other known phytoestrogens. Together, these findings broaden our understanding of the structure-activity relationships for nonsteroidal estrogens and present a series of new chemical prototypes for the future development of potentially useful agonists and antagonists for this nuclear receptor. The wide distribution of weakly estrogenic flavonoid pigments in food crops and medicinal plants raises additional questions about the possible health risks and benefits of these compounds, meriting closer examination of their presence in the human diet.

  2. Modulators of estrogen receptor inhibit proliferation and migration of prostate cancer cells.

    PubMed

    Piccolella, Margherita; Crippa, Valeria; Messi, Elio; Tetel, Marc J; Poletti, Angelo

    2014-01-01

    In the initial stages, human prostate cancer (PC) is an androgen-sensitive disease, which can be pharmacologically controlled by androgen blockade. This therapy often induces selection of androgen-independent PC cells with increased invasiveness. We recently demonstrated, both in cells and mice, that a testosterone metabolite locally synthetized in prostate, the 5α-androstane-3β, 17β-diol (3β-Adiol), inhibits PC cell proliferation, migration and invasion, acting as an anti-proliferative/anti-metastatic agent. 3β-Adiol is unable to bind androgen receptor (AR), but exerts its protection against PC by specifically interacting with estrogen receptor beta (ERβ). Because of its potential retro-conversion to androgenic steroids, 3β-Adiol cannot be used "in vivo", thus, the aims of this study were to investigate the capability of four ligands of ERβ (raloxifen, tamoxifen, genistein and curcumin) to counteract PC progression by mimicking the 3β-Adiol activity. Our results demonstrated that raloxifen, tamoxifen, genistein and curcumin decreased DU145 and PC3 cell proliferation in a dose-dependent manner; in addition, all four compounds significantly decreased the detachment of cells seeded on laminin or fibronectin. Moreover, raloxifen, tamoxifen, genistein and curcumin-treated DU145 and PC3 cells showed a significant decrease in cell migration. Notably, all these effects were reversed by the anti-estrogen, ICI 182,780, suggesting that their actions are mediated by the estrogenic pathway, via the ERβ, the only isoform present in these PCs. In conclusion, these data demonstrate that by selectively activating the ERβ, raloxifen, tamoxifen, genistein and curcumin inhibit human PC cells proliferation and migration favoring cell adesion. These synthetic and natural modulators of ER action may exert a potent protective activity against the progression of PC even in its androgen-independent status.

  3. Licorice Root Components in Dietary Supplements are Selective Estrogen Receptor Modulators with a Spectrum of Estrogenic and Anti-Estrogenic Activities

    PubMed Central

    Boonmuen, Nittaya; Gong, Ping; Ali, Zulfiqar; Chittiboyina, Amar G.; Khan, Ikhlas; Doerge, Daniel R.; Helferich, William G.; Carlson, Kathryn E.; Martin, Teresa; Piyachaturawat, Pawinee; Katzenellenbogen, John A.; Katzenellenbogen, Benita S.

    2016-01-01

    Licorice root extracts are often consumed as botanical dietary supplements by menopausal women as a natural alternative to pharmaceutical hormone replacement therapy. In addition to their components liquiritigenin (Liq) and isoliquiritigenin (Iso-Liq), known to have estrogenic activity, licorice root extracts also contain a number of other flavonoids, isoflavonoids, and chalcones. We have investigated the estrogenic activity of 7 of these components, obtained from an extract of Glycyrrhiza glabra powder, namely Glabridin (L1), Calycosin (L2), Methoxychalcone (L3), Vestitol (L4), Glyasperin C (L5), Glycycoumarin (L6), and Glicoricone (L7), and compared them with Liq, Iso-Liq, and estradiol (E2). All components, including Liq and Iso-Liq, have low binding affinity for estrogen receptors (ERs). Their potency and efficacy in stimulating the expression of estrogen-regulated genes reveal that Liq and Iso-Liq and L2, L3, L4, and L6 are estrogen agonists. Interestingly, L3 and L4 have an efficacy nearly equivalent to E2 but with a potency ca. 10,000-fold less. The other components, L1, L5 and L7, acted as partial estrogen antagonists. All agonist activities were reversed by the antiestrogen, ICI 182,780, or by knockdown of ERα with siRNA, indicating that they are ER dependent. In HepG2 hepatoma cells stably expressing ERα, only Liq, Iso-Liq, and L3 stimulated estrogen-regulated gene expression, and in all cases gene stimulation did not occur in HepG2 cells lacking ERα. Collectively, these findings classify the components of licorice root extracts as low potency, mixed ER agonists and antagonists, having a character akin to that of selective estrogen receptor modulators or SERMs. PMID:26631549

  4. Coptis extracts enhance the anticancer effect of estrogen receptor antagonists on human breast cancer cells.

    PubMed

    Liu, Jing; He, Chengwei; Zhou, Keyuan; Wang, Jingdong; Kang, Jing X

    2009-01-09

    Estrogen receptor (ER) antagonists have been widely used for breast cancer treatment, but the efficacy and drug resistance remain to be clinical concerns. The purpose of this study was to determine whether the extracts of coptis, an anti-inflammatory herb, improve the anticancer efficacy of ER antagonists. The results showed that the combined treatment of ER antagonists and the crude extract of coptis or its purified compound berberine conferred synergistic growth inhibitory effect on MCF-7 cells (ER+), but not on MDA-MB-231 cells (ER-). Similar results were observed in the combined treatment of fulvestrant, a specific aromatase antagonist. Analysis of the expression of breast cancer related genes indicated that EGFR, HER2, bcl-2, and COX-2 were significantly downregulated, while IFN-beta and p21 were remarkably upregulated by berberine. Our results suggest that coptis extracts could be promising adjuvant to ER antagonists in ER positive breast cancer treatment through regulating expression of multiple genes.

  5. Thioredoxin and thioredoxin reductase influence estrogen receptor alpha-mediated gene expression in human breast cancer cells.

    PubMed

    Rao, Abhi K; Ziegler, Yvonne S; McLeod, Ian X; Yates, John R; Nardulli, Ann M

    2009-12-01

    Accumulation of reactive oxygen species (ROS) in cells damages resident proteins, lipids, and DNA. In order to overcome the oxidative stress that occurs with ROS accumulation, cells must balance free radical production with an increase in the level of antioxidant enzymes that convert free radicals to less harmful species. We identified two antioxidant enzymes, thioredoxin (Trx) and Trx reductase (TrxR), in a complex associated with the DNA-bound estrogen receptor alpha (ERalpha). Western analysis and immunocytochemistry were used to demonstrate that Trx and TrxR are expressed in the cytoplasm and in the nuclei of MCF-7 human breast cancer cells. More importantly, endogenously expressed ERalpha, Trx, and TrxR interact and ERalpha and TrxR associate with the native, estrogen-responsive pS2 and progesterone receptor genes in MCF-7 cells. RNA interference assays demonstrated that Trx and TrxR differentially influence estrogen-responsive gene expression and that together, 17beta-estradiol, Trx, and TrxR alter hydrogen peroxide (H(2)O(2)) levels in MCF-7 cells. Our findings suggest that Trx and TrxR are multifunctional proteins that, in addition to modulating H(2)O(2) levels and transcription factor activity, aid ERalpha in regulating the expression of estrogen-responsive genes in target cells.

  6. Linking estrogen receptor β expression with inflammatory bowel disease activity

    PubMed Central

    Pierdominici, Marina; Maselli, Angela; Varano, Barbara; Barbati, Cristiana; Cesaro, Paola; Spada, Cristiano; Zullo, Angelo; Lorenzetti, Roberto; Rosati, Marco; Rainaldi, Gabriella; Limiti, Maria Rosaria; Guidi, Luisa

    2015-01-01

    Crohn disease (CD) and ulcerative colitis (UC) are chronic forms of inflammatory bowel disease (IBD) whose pathogenesis is only poorly understood. Estrogens have a complex role in inflammation and growing evidence suggests that these hormones may impact IBD pathogenesis. Here, we demonstrated a significant reduction (p < 0.05) of estrogen receptor (ER)β expression in peripheral blood T lymphocytes from CD/UC patients with active disease (n = 27) as compared to those in remission (n = 21) and healthy controls (n = 29). Accordingly, in a subgroup of CD/UC patients undergoing to anti-TNF-α therapy and responsive to treatment, ERβ expression was higher (p < 0.01) than that observed in not responsive patients and comparable to that of control subjects. Notably, ERβ expression was markedly decreased in colonic mucosa of CD/UC patients with active disease, reflecting the alterations observed in peripheral blood T cells. ERβ expression inversely correlated with interleukin (IL)-6 serum levels and exogenous exposure of both T lymphocytes and intestinal epithelial cells to this cytokine resulted in ERβ downregulation. These results demonstrate that the ER profile is altered in active IBD patients at both mucosal and systemic levels, at least in part due to IL-6 dysregulation, and highlight the potential exploitation of T cell-associated ERβ as a biomarker of endoscopic disease activity. PMID:26497217

  7. Estrogen receptor agonists/antagonists in breast cancer therapy: A critical review.

    PubMed

    Jameera Begam, A; Jubie, S; Nanjan, M J

    2017-04-01

    Estrogens display intriguing tissue selective action that is of great biomedical importance in the development of optimal therapeutics for the prevention and treatment of breast cancer. There are also strong evidences to show that both endogenous and exogenous estrogens are involved in the pathogenesis of breast cancer. Tamoxifen has been the only drug of choice for more than 30years to treat patients with estrogen related (ER) positive breast tumors. There is a need therefore, for identifying newer, potential and novel candidates for breast cancer. Keeping this in view, the present review focuses on selective estrogen receptor modulators and estrogen antagonists such as sulfatase and aromatase inhibitors involved in breast cancer therapy. A succinct and critical overview of the structure of estrogen receptors, their signaling and involvement in breast carcinogenesis are herein described.

  8. Modulation of the estrogen receptor structure, evidence of a heterogeneity

    SciTech Connect

    Toulas, C.; Guilbaud, N.; Delassus, F.; Bayard, F.; Faye, J.C. )

    1990-01-01

    In order to analyse the molecular weight polymorphism of the estrogen receptor (ER) in MCF-7 cells, we have developed a procedure which allowed in situ linkage of ER by (3H) tamoxifen aziridine and provided labelled proteins in conditions which minimized protease activities. After labelling, cell lysis was performed in SDS buffer containing various concentrations of mercaptoethanol. Proteins extracted with phenolic solution and precipitated by cold acetone were analysed by SDS PAGE. It appears that beside the form of 67 kDa already described, binding entities of tamoxifen aziridine were also present at a molecular mass of 110 kDa and 45 kDa. On the other hand, investigations on the effect of 12-0-Tetradecanoyl Phorbol 13-Acetate (TPA) showed that TPA induces a decrease of the 67 kDa entity.

  9. The Effect of Prolonged Cold Ischemia Time on Estrogen Receptor Immunohistochemistry in Breast Cancer

    PubMed Central

    Li, Xiaoxian; Deavers, Michael T.; Guo, Ming; Liu, Ping; Gong, Yun; Albarracin, Constance T.; Middleton, Lavinia P.; Huo, Lei

    2013-01-01

    To facilitate accurate detection of estrogen receptor expression in breast tumors, the American Society of Clinical Oncology/College of American Pathologists recommends that cold ischemia time be kept under 1 h. However, data to address the upper threshold of cold ischemia time are limited. While it is our routine practice to keep cold ischemia time under 1 h for breast core biopsy specimens, this is difficult for surgical specimens because of the comprehensive intraoperative assessment performed at our institution. In this retrospective study, we compared estrogen receptor immunohistochemical staining results in paired breast tumor core biopsy specimens and resection specimens with cold ischemia times ranging from 64 to 357 min in 97 patients. The staining category (≥10%, positive; 1-9%, low positive; <1%, negative) between the core biopsy and resection specimens changed for 5 patients (5%). The weighted Kappa statistic for estrogen receptor staining category between the two specimen types was 0.86 (95% confidence interval, 0.74-0.99), indicating good concordance. The difference in the percentage of estrogen receptor staining between core biopsy and resection was not significantly associated with cold ischemia time (P = 0.81, Spearman correlation). Although we did not observe significant associations between the difference in estrogen receptor staining in the two specimen types and cold ischemia time after placing the patients in three groups of ‘increase’, ‘decrease’ and ‘no change’ using a difference of 25% in estrogen receptor staining percentage as the cutoff, a trend of decreased estrogen receptor staining with cold ischemia time > 2 h was detected. No statistically significant association was found between the change of estrogen receptor staining and the history of neoadjuvant chemotherapy. Our findings indicate that prolonged cold ischemia time up to 4 h (97% of our cohort) in the practice setting of our institution has minimal clinical impact

  10. Estrogens Induce Expression of Membrane-Associated Estrogen Receptor α Isoforms in Lactotropes

    PubMed Central

    Zárate, Sandra; Jaita, Gabriela; Ferraris, Jimena; Eijo, Guadalupe; Magri, María L.; Pisera, Daniel; Seilicovich, Adriana

    2012-01-01

    Estrogens are key to anterior pituitary function, stimulating hormone release and controlling cell fate to achieve pituitary dynamic adaptation to changing physiological conditions. In addition to their classical mechanism of action through intracellular estrogen receptors (ERs), estrogens exert rapid actions via cell membrane-localized ERs (mERs). We previously showed that E2 exerts a rapid pro-apoptotic action in anterior pituitary cells, especially in lactotropes and somatotropes, through activation of mERs. In the present study, we examined the involvement of mERα in the rapid pro-apoptotic action of estradiol by TUNEL in primary cultures of anterior pituitary cells from ovariectomized rats using a cell-impermeable E2 conjugate (E2-BSA) and an ERα selective antagonist (MPP dihydrochloride). We studied mERα expression during the estrous cycle and its regulation by gonadal steroids in vivo by flow cytometry. We identified ERα variants in the plasma membrane of anterior pituitary cells during the estrous cycle and studied E2 regulation of these mERα variants in vitro by surface biotinylation and Western Blot. E2-BSA-induced apoptosis was abrogated by MPP in total anterior pituitary cells and lactotropes. In cycling rats, we detected a higher number of lactotropes and a lower number of somatotropes expressing mERα at proestrus than at diestrus. Acute E2 treatment increased the percentage of mERα-expressing lactotropes whereas it decreased the percentage of mERα-expressing somatotropes. We detected three mERα isoforms of 66, 39 and 22 kDa. Expression of mERα66 and mERα39 was higher at proestrus than at diestrus, and short-term E2 incubation increased expression of these two mERα variants. Our results indicate that the rapid apoptotic action exerted by E2 in lactotropes depends on mERα, probably full-length ERα and/or a 39 kDa ERα variant. Expression and activation of mERα variants in lactotropes could be one of the mechanisms through which E2

  11. Current medical treatment of estrogen receptor-positive breast cancer

    PubMed Central

    Lumachi, Franco; Santeufemia, Davide A; Basso, Stefano MM

    2015-01-01

    Approximately 80% of breast cancers (BC) are estrogen receptor (ER)-positive and thus endocrine therapy (ET) should be considered complementary to surgery in the majority of patients. The advantages of oophorectomy, adrenalectomy and hypophysectomy in women with advanced BC have been demonstrated many years ago, and currently ET consist of (1) ovarian function suppression (OFS), usually obtained using gonadotropin-releasing hormone agonists (GnRHa); (2) selective estrogen receptor modulators or down-regulators (SERMs or SERDs); and (3) aromatase inhibitors (AIs), or a combination of two or more drugs. For patients aged less than 50 years and ER+ BC, there is no conclusive evidence that the combination of OFS and SERMs (i.e., tamoxifen) or chemotherapy is superior to OFS alone. Tamoxifen users exhibit a reduced risk of BC, both invasive and in situ, especially during the first 5 years of therapy, and extending the treatment to 10 years further reduced the risk of recurrences. SERDs (i.e., fulvestrant) are especially useful in the neoadjuvant treatment of advanced BC, alone or in combination with either cytotoxic agents or AIs. There are two types of AIs: type I are permanent steroidal inhibitors of aromatase, while type II are reversible nonsteroidal inhibitors. Several studies demonstrated the superiority of the third-generation AIs (i.e., anastrozole and letrozole) compared with tamoxifen, and adjuvant therapy with AIs reduces the recurrence risk especially in patients with advanced BC. Unfortunately, some cancers are or became ET-resistant, and thus other drugs have been suggested in combination with SERMs or AIs, including cyclin-dependent kinase 4/6 inhibitors (palbociclib) and mammalian target of rapamycin (mTOR) inhibitors, such as everolimus. Further studies are required to confirm their real usefulness. PMID:26322178

  12. Alteration of Large-Scale Chromatin Structure by Estrogen Receptor

    PubMed Central

    Nye, Anne C.; Rajendran, Ramji R.; Stenoien, David L.; Mancini, Michael A.; Katzenellenbogen, Benita S.; Belmont, Andrew S.

    2002-01-01

    The estrogen receptor (ER), a member of the nuclear hormone receptor superfamily important in human physiology and disease, recruits coactivators which modify local chromatin structure. Here we describe effects of ER on large-scale chromatin structure as visualized in live cells. We targeted ER to gene-amplified chromosome arms containing large numbers of lac operator sites either directly, through a lac repressor-ER fusion protein (lac rep-ER), or indirectly, by fusing lac repressor with the ER interaction domain of the coactivator steroid receptor coactivator 1. Significant decondensation of large-scale chromatin structure, comparable to that produced by the ∼150-fold-stronger viral protein 16 (VP16) transcriptional activator, was produced by ER in the absence of estradiol using both approaches. Addition of estradiol induced a partial reversal of this unfolding by green fluorescent protein-lac rep-ER but not by wild-type ER recruited by a lac repressor-SRC570-780 fusion protein. The chromatin decondensation activity did not require transcriptional activation by ER nor did it require ligand-induced coactivator interactions, and unfolding did not correlate with histone hyperacetylation. Ligand-induced coactivator interactions with helix 12 of ER were necessary for the partial refolding of chromatin in response to estradiol using the lac rep-ER tethering system. This work demonstrates that when tethered or recruited to DNA, ER possesses a novel large-scale chromatin unfolding activity. PMID:11971975

  13. Profiling of benzophenone derivatives using fish and human estrogen receptor-specific in vitro bioassays

    SciTech Connect

    Molina-Molina, Jose-Manuel Escande, Aurelie; Pillon, Arnaud; Gomez, Elena; Pakdel, Farzad; Cavailles, Vincent; Olea, Nicolas; Ait-Aissa, Selim; Balaguer, Patrick

    2008-11-01

    Benzophenone (BP) derivatives, BP1 (2,4-dihydroxybenzophenone), BP2 (2,2',4,4'-tetrahydroxybenzophenone), BP3 (2-hydroxy-4-methoxybenzophenone), and THB (2,4,4'-trihydroxybenzophenone) are UV-absorbing chemicals widely used in pharmaceutical, cosmetics, and industrial applications, such as topical sunscreens in lotions and hair sprays to protect skin and hair from UV irradiation. Studies on their endocrine disrupting properties have mostly focused on their interaction with human estrogen receptor alpha (hER{alpha}), and there has been no comprehensive analysis of their potency in a system allowing comparison between hER{alpha} and hER{beta} activities. The objective of this study was to provide a comprehensive ER activation profile of BP derivatives using ER from human and fish origin in a battery of in vitro tests, i.e., competitive binding, reporter gene based assays, vitellogenin (Vtg) induction in isolated rainbow trout hepatocytes, and proliferation based assays. The ability to induce human androgen receptor (hAR)-mediated reporter gene expression was also examined. All BP derivatives tested except BP3 were full hER{alpha} and hER{beta} agonists (BP2 > THB > BP1) and displayed a stronger activation of hER{beta} compared with hER{alpha}, the opposite effect to that of estradiol (E{sub 2}). Unlike E{sub 2}, BPs were more active in rainbow trout ER{alpha} (rtER{alpha}) than in hER{alpha} assay. All four BP derivatives showed anti-androgenic activity (THB > BP2 > BP1 > BP3). Overall, the observed anti-androgenic potencies of BP derivatives, together with their proposed greater effect on ER{beta} versus ER{alpha} activation, support further investigation of their role as endocrine disrupters in humans and wildlife.

  14. Assessment of estrogen receptor-monoclonal antibody interaction by high performance liquid chromatography

    SciTech Connect

    Brandt, D.W.; Wittliff, J.L.

    1986-05-01

    To define the interrelationships between the various isoforms of the estrogen receptors (ER), a monoclonal antibody-horse radish peroxidase conjugate H222 was used as a probe in conjunction with HPIEC (Synchrom AX-1000) and HPSEC (TSK-3000 SW Toyo Soda) columns. ER from breast tumors was assessed using (16..cap alpha..-/sup 125/I)-iodoestradiol-17..beta.. (3nM) +/-200 fold excess estradiol-17..beta.. and excess H222. When ER was analyzed by HPSEC (size and shape), with 400 mM KCl which caused the dissociation of ER into 4S isoforms, a shift in retension time to higher molecular weight species was seen. The H222 appeared to interact with most isoforms of ER. However, when ER was analyzed by HPIEC (surface charge) with H222, a shift in virtually all of the high salt (150mM) isoform to the flow-through was observed with only 46% shift in elution of the low salt (60-70mM) isoforms. H222 did not alter total ER binding capacity. These data suggest that H222 recognized discrete forms of the ER. Therefore, modification in the receptor may have occurred which masks or removes the antigenic determinant limiting the specificity of H222. These results indicate that H222 may be employed as a tool to elucidate the interrelationships between these ER species.

  15. Serum estrogen receptor bioactivity and breast cancer risk among postmenopausal women

    PubMed Central

    Lim, Vanessa W; Li, Jun; Gong, Yinhan; Jin, Aizhen; Yuan, Jian-Min; Yong, Eu Leong; Koh, Woon-Puay

    2014-01-01

    The estrogen levels of Asian women are different from those of Western women, and this could affect estrogen receptor (ER) bioactivity and breast cancer risk. We conducted a case-control study of 169 postmenopausal breast cancer cases and 426 matched controls nested within a population-based prospective cohort, The Singapore Chinese Health Study, to evaluate serum levels of estrogens and their receptor (ERα and ERβ)-mediated estrogenic activities in relation to breast cancer risk. Breast cancer cases had higher levels of estrogens and estrogen receptor mediated bioactivities in baseline serum than controls. Compared to the lowest quartile, women in the highest quartile for estrone or ERα-mediated bioactivity had increased breast cancer risk. After additional adjustment for ERβ bioactivity, free E2 and estrone; serum ERα-mediated estrogenic activity remained associated with increased breast cancer risk. Compared to the lowest quartile, women in the highest quartile for ERα-mediated bioactivity had an odds ratio of 2.39 (95% confidence interval=1.17–4.88, p for trend=0.016). Conversely, the positive association between estrone and cancer risk became null after adjustment for ERα-mediated estrogenic activity, suggesting that the effect of estrone could be mediated through ERα. Identification of the factor(s) contributing to increased ERα-mediated estrogenic bioactivity in sera, and its role as a predictor for breast cancer risk needs to be validated in future studies. PMID:24322303

  16. An estrogen receptor model to describe the regulation of prolactin synthesis by antiestrogens in vitro.

    PubMed

    Lieberman, M E; Gorski, J; Jordan, V C

    1983-04-25

    A hypothetical model of the ligand interaction with the estrogen receptor binding site has been developed to describe the structural features necessary to initiate or to inhibit prolactin synthesis in vitro. The biological potency of the binding ligands is directly related to their relative binding affinity (RBA) for the estrogen receptor. The relative potencies of antiestrogens to inhibit estradiol-stimulated prolactin synthesis was trans-monohydroxytamoxifen identical to cis-monohydroxytamoxifen identical to tamoxifen, consistent with their RBAs for uterine estrogen receptor. Similarly the relative potency of estrogens to stimulate prolactin synthesis was diethylstilbestrol identical to estradiol greater than ICI 77,949 greater than ICI 47,699 identical to zuclomiphene, consistent with their RBAs. The compound LY126412 (trioxifene without the aminoethoxy side chain) did not interact with the estrogen receptor at the concentrations tested (10(-8)--10(-6) M) or exhibit estrogenic or antiestrogenic properties using the prolactin synthesis assay. Overall, the ligand-receptor model stresses the structural requirement for high affinity binding and the critical positioning of the alkylamino-ethoxy side chain in space (in relation to the ligand-binding site on the estrogen receptor) to prevent prolactin synthesis.

  17. Activation of Estrogen Receptor Transfected into a Receptor-Negative Brest Cancer Cell Line Decreases the Metastatic and Invasive Potential of the Cells

    NASA Astrophysics Data System (ADS)

    Garcia, Marcel; Derocq, Danielle; Freiss, Gilles; Rochefort, Henri

    1992-12-01

    Breast cancers containing estrogen receptors are responsive to antiestrogen treatment and have a better prognosis than estrogen receptor-negative tumors. The loss of estrogen and progesterone receptors appears to be associated with a progression to less-differentiated tumors. We transfected the human estrogen receptor into the estrogen receptor-negative metastatic breast cancer cell line MDA-MB-231 in an attempt to restore their sensitivity to antiestrogens. Two stable sublines of MDA-MB-231 cells (HC1 and HE5) expressing functional estrogen receptors were studied for their ability to grow and invade in vitro and to metastasize in athymic nude mice. The number and size of lung metastases developed by these two sublines in ovariectomized nude mice was not markedly altered by tamoxifen but was inhibited 3-fold by estradiol. Estradiol also significantly inhibited in vitro cell proliferation of these sublines and their invasiveness in Matrigel, a reconstituted basement membrane, whereas the antiestrogens 4-hydroxytamoxifen and ICI 164,384 reversed these effects. These results show that estradiol inhibits the metastatic ability of estrogen receptornegative breast cancer cells following transfection with the estrogen receptor, whereas estrogen receptor-positive breast cancers are stimulated by estrogen, indicating that factors other than the estrogen receptor are involved in progression toward hormone independence. Reactivation or transfer of the estrogen receptor gene can therefore be considered as therapeutic approaches to hormone-independent cancers

  18. Novel drugs that target the estrogen-related receptor alpha: their therapeutic potential in breast cancer

    PubMed Central

    May, Felicity EB

    2014-01-01

    The incidence of breast cancer continues to rise: 1.7 million women were diagnosed with and 521,000 women died from breast cancer in 2012. This review considers first current treatment options: surgery; radiotherapy; and systemic endocrine, anti-biological, and cytotoxic therapies. Clinical management includes prevention, early detection by screening, treatment with curative intent, management of chronic disease, and palliative control of advanced breast cancer. Next, the potential of novel drugs that target DNA repair, growth factor dependence, intracellular and intercellular signal transduction, and cell cycle are considered. Estrogen-related receptor alpha has attracted attention as a therapeutic target in triple-negative breast cancers with de novo resistance to, and in breast cancers with acquired resistance to, endocrine therapies such as antiestrogens and aromatase inhibitors. Estrogen-related receptor alpha is an orphan receptor and transcription factor. Its activity is regulated by coregulator proteins and posttranslational modification. It is an energy sensor that controls adaptation to energy demand and may facilitate glycolytic metabolism and mitochondrial oxidative respiration in breast cancer cells. Estrogen-related receptor alpha increases breast cancer cell migration, proliferation, and tumor development. It is expressed at high levels in estrogen receptor-negative tumors, and is proposed to activate estrogen-responsive genes in endocrine-resistant tumors. The structures and functions of the ligand-binding domains of estrogen receptor alpha and estrogen-related receptor alpha, their ability to bind estrogens, phytoestrogens, and synthetic ligands, and the effects of ligand agonists, antagonists, and inverse agonists on biological activity, are evaluated. Synthetic ligands of estrogen-related receptor alpha have activity in preclinical models of metabolic disorders, diabetes, osteoporosis, and oncology. The clinical settings in which these novel

  19. The sexually dimorphic role of adipose and adipocyte estrogen receptors in modulating adipose tissue expansion, inflammation, and fibrosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our data demonstrate that estrogens, estrogen receptor-alpha (ERalpha), and estrogen receptor-ßeta (ERßeta) regulate adipose tissue distribution, inflammation, fibrosis, and glucose homeostasis, by determining that alphaERKO mice have increased adipose tissue inflammation and fibrosis prior to obesi...

  20. KRÜPPEL-LIKE FACTOR 9 AND REGULATION OF ENDOMETRIAL ESTROGEN RECEPTOR-ALPHA SIGNALING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endometrial cancer risk is linked to aberrant estrogen receptor-alpha (ER alpha) signaling caused by increased ER alpha activation due to hyper-estrogenic environments or mutations in growth-regulatory factors. We had shown that ER alpha signaling is attenuated by the Sp1-related transcription facto...

  1. The relationship between ovarian steroids and uterine estrogen receptors during late pregnancy

    SciTech Connect

    Cathey, T.M.; Chung, Kyung W. )

    1991-01-01

    Although a direct interdependence exists between the ovarian steroids, estrogen and progesterone, the exact role of these two hormones during pregnancy, especially late pregnancy, is not completely understood. Investigations have been conducted to determine whether the circulating levels of progesterone and estrogen or changes in the ratio of progesterone/estrogen in relation to the concentration of uterine estrogen receptors are associated with triggering parturition. Ninety-day old female rats were sacrificed at gestation days 14, 16, 18, 20 and two days post-partum. The plasma levels of estradiol and progesterone were measured by solid-phase radioimmunoassay. Uterine cytosol was subjected to a charcoal binding assay to determine the concentration of estrogen receptors. Our findings demonstrate that there is a significant drop in both plasma progesterone and estradiol during late pregnancy. Also indicated is a significant increase in uterine estrogen receptors throughout late pregnancy. Finally, during this period there is a direct correlation between the shift in the progesterone/estrogen ratio and the increase in the concentration of uterine estrogen receptors in late pregnancy.

  2. Integration of Nuclear- and Extranuclear-Initiated Estrogen Receptor Signaling in Breast Cancer Cells

    ERIC Educational Resources Information Center

    Madak Erdogan, Zeynep

    2009-01-01

    Estrogenic hormones exert their effects through binding to Estrogen Receptors (ERs), which work in concert with coregulators and extranuclear signaling pathways to control gene expression in normal as well as cancerous states, including breast tumors. In this thesis, we have used multiple genome-wide analysis tools to elucidate various ways that…

  3. Identification and Biological Evaluation of Coactivator Binding Inhibitors for the Estrogen Receptor

    ERIC Educational Resources Information Center

    Gunther, Jillian Rebecca

    2009-01-01

    The physiologic effects of estrogen action through the estrogen receptor (ER) are widespread, as this hormone exerts actions in both reproductive (e.g., uterus) and non-reproductive (e.g., bone, brain) tissues in both men and women. As such, the regulation of the activity of this ligand-activated transcription factor is highly relevant to the…

  4. Effect of nonpersistent pesticides on estrogen receptor, androgen receptor, and aryl hydrocarbon receptor.

    PubMed

    Medjakovic, Svjetlana; Zoechling, Alfred; Gerster, Petra; Ivanova, Margarita M; Teng, Yun; Klinge, Carolyn M; Schildberger, Barbara; Gartner, Michael; Jungbauer, Alois

    2014-10-01

    Nonpersistent pesticides are considered less harmful for the environment, but their impact as endocrine disruptors has not been fully explored. The pesticide Switch was applied to grape vines, and the maximum residue concentration of its active ingredients was quantified. The transactivation potential of the pesticides Acorit, Frupica, Steward, Reldan, Switch, Cantus, Teldor, and Scala and their active compounds (hexythiazox, mepanipyrim, indoxacarb, chlorpyrifos-methyl, cyprodinil, fludioxonil, boscalid, fenhexamid, and pyrimethanil) were tested on human estrogen receptor α (ERα), androgen receptor (AR) and arylhydrocarbon receptor (AhR) in vitro. Relative binding affinities of the pure pesticide constituents for AR and their effect on human breast cancer and prostate cancer cell lines were evaluated. Residue concentrations of Switch's ingredients were below maximum residue limits. Fludioxonil and fenhexamid were ERα agonists (EC50 -values of 3.7 and 9.0 μM, respectively) and had time-dependent effects on endogenous ERα-target gene expression (cyclin D1, progesterone receptor, and nuclear respiratory factor 1) in MCF-7 human breast cancer cells. Fludioxonil, mepanipyrim, cyprodinil, pyrimethanil, and chlorpyrifos-methyl were AhR-agonists (EC50 s of 0.42, 0.77, 1.4, 4.6, and 5.1 μM, respectively). Weak AR binding was shown for chlorpyrifos-methyl, cyprodinil, fenhexamid, and fludioxonil. Assuming a total uptake which does not take metabolism and clearance rates into account, our in vitro evidence suggests that pesticides could activate pathways affecting hormonal balance, even within permitted limits, thus potentially acting as endocrine disruptors.

  5. Bisphenol-A rapidly promotes dynamic changes in hippocampal dendritic morphology through estrogen receptor-mediated pathway by concomitant phosphorylation of NMDA receptor subunit NR2B

    SciTech Connect

    Xu Xiaohong Ye Yinping; Li Tao; Chen Lei; Tian Dong; Luo Qingqing; Lu Mei

    2010-12-01

    Bisphenol-A (BPA) is known to be a potent endocrine disrupter. Evidence is emerging that estrogen exerts a rapid influence on hippocampal synaptic plasticity and the dendritic spine density, which requires activation of NMDA receptors. In the present study, we investigated the effects of BPA (ranging from 1 to 1000 nM), focusing on the rapid dynamic changes in dendritic filopodia and the expressions of estrogen receptor (ER) {beta} and NMDA receptor, as well as the phosphorylation of NMDA receptor subunit NR2B in the cultured hippocampal neurons. A specific ER antagonist ICI 182,780 was used to examine the potential involvement of ERs. The results demonstrated that exposure to BPA (ranging from 10 to 1000 nM) for 30 min rapidly enhanced the motility and the density of dendritic filopodia in the cultured hippocampal neurons, as well as the phosphorylation of NR2B (pNR2B), though the expressions of NMDA receptor subunits NR1, NR2B, and ER{beta} were not changed. The antagonist of ERs completely inhibited the BPA-induced increases in the filopodial motility and the number of filopodia extending from dendrites. The increased pNR2B induced by BPA (100 nM) was also completely eliminated. Furthermore, BPA attenuated the effects of 17{beta}-estradiol (17{beta}-E{sub 2}) on the dendritic filopodia outgrowth and the expression of pNR2B when BPA was co-treated with 17{beta}-E{sub 2}. The present results suggest that BPA, like 17{beta}-E{sub 2}, rapidly results in the enhanced motility and density of dendritic filopodia in the cultured hippocampal neurons with the concomitant activation of NMDA receptor subunit NR2B via an ER-mediated signaling pathway. Meanwhile, BPA suppressed the enhancement effects of 17{beta}-E{sub 2} when it coexists with 17{beta}-E{sub 2}. These results provided important evidence suggesting the neurotoxicity of the low levels of BPA during the early postnatal development of the brain.

  6. Defining a minimal estrogen receptor DNA binding domain.

    PubMed Central

    Mader, S; Chambon, P; White, J H

    1993-01-01

    The estrogen receptor (ER) is a transcriptional regulator which binds to cognate palindromic DNA sequences known as estrogen response elements (EREs). A 66 amino acid core region which contains two zinc fingers and is highly conserved among the nuclear receptors is essential for site specific DNA recognition. However, it remains unclear how many flanking amino acids in addition to the zinc finger core are required for DNA binding. Here, we have characterized the minimal DNA binding region of the human ER by analysing the DNA binding properties of a series of deletion mutants expressed in bacteria. We find that the 66 amino acid zinc finger core of the DBD fails to bind DNA, and that the C-terminal end of the minimal ER DBD required for binding to perfectly palindromic EREs corresponds to the limit of 100% amino acid homology between the chicken and human receptors, which represents the boundary between regions C and D in the ER. Moreover, amino acids of region D up to 30 residues C-terminal to the zinc fingers greatly stabilize DNA binding by the DBD to perfectly palindromic EREs and are absolutely required for formation of gel retardation complexes by the DBD on certain physiological imperfectly palindromic EREs. These results indicate that in addition to the zinc finger core, amino acids C-terminal to the core in regions C and D play a key role in DNA binding by the ER, particularly to imperfectly palindromic response elements. The ER DBD expressed in E. coli binds as a dimer to ERE palindromes in a highly cooperative manner and forms only low levels of monomeric protein-DNA complexes on either palindromic or half-palindromic response elements. Conversion of ER amino acids 222 to 226, which lie within region C, to the corresponding residues of the human RAR alpha abolishes formation of dimeric protein-DNA complexes. Conversely, replacement of the same region of RAR alpha with ER residues 222 to 226 creates a derivative that, unlike the RAR alpha DBD, binds

  7. Thiophene-Core Estrogen Receptor Ligands Having Superagonist Activity

    PubMed Central

    Min, Jian; Wang, Pengcheng; Srinivasan, Sathish; Nwachukwu, Jerome C.; Guo, Pu; Huang, Minjian; Carlson, Kathryn E.; Katzenellenbogen, John A.; Nettles, Kendall W.; Zhou, Hai-Bing

    2013-01-01

    To probe the importance of the heterocyclic core of estrogen receptor (ER) ligands, we prepared a series of thiophene-core ligands by Suzuki cross-coupling of aryl boronic acids with bromo-thiophenes, and we assessed their receptor binding and cell biological activities. The disposition of the phenol substituents on the thiophene core, at alternate or adjacent sites, and the nature of substituents on these phenols all contribute to binding affinity and subtype selectivity. Most of the bis(hydroxyphenyl)-thiophenes were ERβ selective, whereas the tris(hydroxyphenyl)-thiophenes were ERα selective; analogous furan-core compounds generally have lower affinity and less selectivity. Some diarylthiophenes show distinct superagonist activity in reporter gene assays, giving maximal activities 2–3 times that of estradiol, and modeling suggests that these ligands have a different interaction with a hydrogen-bonding residue in helix-11. Ligand-core modification may be a new strategy for developing ER ligands whose selectivity is based on having transcriptional activity greater than that of estradiol. PMID:23586645

  8. Bromine-80m-labeled estrogens: Auger-electron emitting, estrogen receptor-directed ligands with potential for therapy of estrogen receptor positive cancers

    SciTech Connect

    DeSombre, E.R.; Mease, R.C.; Hughes, A.; Harper, P.V.; DeJesus, O.T.; Friedman, A.M.

    1988-01-01

    A triphenylbromoethylene, 1,1-bis(p-hydroxyphenyl)-2-bromo-2-phenylethylene, Br-BHPE, and a bromosteroidal estrogen, 17..cap alpha..- bromovinylestradiol, BrVE/sub 2/, were labeled with the Auger electron emitting nuclide bromine-80m, prepared by the (p,n) reaction with /sup 80/Se. To assess their potential as estrogen receptor (ER) directed therapeutic substrates the bromine-80m labeled estrogens were injected into immature female rats and the tissue distribution studied at 0.5 and 2 hours. Both radiobromoestrogens showed substantial diethylstilbesterol (DES)-inhibitable localization in the ER rich tissues, uterus, pituitary, ovary and vagina at both time points. While the percent dose per gram tissue was higher for the Br-BHPE, the BrVE/sub 2/ showed higher tissue to blood ratios, especially at 2 hr, reflecting the lower blood concentrations of radiobromine following administration of the steroidal bromoestrogen. Comparing intraperitoneal, intravenous and subcutaneous routes of administration for the radiobromine labeled Br-BHPE, the intraperitoneal route was particularly advantageous to provide maximum, DES-inhibitable concentrations in the peritoneal, ER-rich target organs, the uterus, ovary and vagina. While uterine concentrations after BrBHPE were from 10--48% dose/g and after BrVE/sub 2/ were 15--25% dose/g, similar treatment with /sup 80m/Br as sodium bromide showed uniform low concentrations in all tissues at about the levels seen in blood. The effective specific activity of (/sup 80m/Br)BrBHPE, assayed by specific binding to ER in rat uterine cytosol, was 8700 Ci/mmole. 23 refs., 9 figs., 2 tabs.

  9. Estrogen receptor alpha polymorphisms and the risk of malignancies.

    PubMed

    Anghel, Andrei; Narita, Diana; Seclaman, Edward; Popovici, Emilian; Anghel, Mariana; Tamas, Liviu

    2010-12-01

    Estrogens represent risk factors for endocrine-related cancers and play also an important role in the development and progression of other malignancies. In order to analyze the associations between estrogen receptor gene alpha polymorphisms and cancers susceptibility, we genotyped six single nucleotide polymorphisms (SNPs) in 163 Caucasian cancer patients--103 breast cancers and 60 other malignancies (colorectal, bladder, hepatocellular carcinoma and acute myeloid leukemia)--and 114 healthy controls using hybridization probes. We performed Armitage`s association trend-test to evaluate the risk. Linkage disequilibrium (LD) was assessed for each pair of markers. The genotypes CC and CT of rs3798577 were significantly associated with the cancers risk (p-trend breast = 4 × 10(-5); p-trend cancers = 1 × 10(-5)); in discrepancy with breast cancer where the C-allele represented the risk allele, for bladder, hepatocellular carcinomas and leukemia, the T allele seems to confer susceptibility. The minor G allele of rs1801132 was protective in our cases (p = 1 × 10(-4)); for rs2228480, the heterozygous frequency was higher for cancer groups (p = 0.03); the SNP pairs rs2228480&rs3798577 and rs2234693&rs9340799 were in low LD; the haplotypes T-A of rs2234693&rs9340799 and G-C of rs2228480&rs3798577 showed a trend to be higher represented in breast cancers; T allele of rs2234693 was higher expressed in breast, colon cancers and leukemia; rs2077647 was associated with colon (p = 0.008, C-risk allele) and bladder (p = 0.01, T-risk allele) cancers. We concluded that ESR1 polymorphisms may have distinct impact in carcinogenesis and further genotyping will establish whether these findings remain significant in larger cohorts.

  10. Design and Synthesis of Norendoxifen Analogues with Dual Aromatase Inhibitory and Estrogen Receptor Modulatory Activities

    PubMed Central

    Lv, Wei; Liu, Jinzhong; Skaar, Todd C.; Flockhart, David A.; Cushman, Mark

    2015-01-01

    Both selective estrogen receptor modulators and aromatase inhibitors are widely used for the treatment of breast cancer. Compounds with both aromatase inhibitory and estrogen receptor modulatory activities could have special advantages for treatment of breast cancer. Our previous efforts led to the discovery of norendoxifen as the first compound with dual aromatase inhibitory and estrogen receptor binding activities. To optimize its efficacy and aromatase selectivity versus other cytochrome P450 enzymes, a series of structurally related norendoxifen analogues were designed and synthesized. The most potent compound, 4'-hydroxynorendoxifen (10), displayed elevated inhibitory potency against aromatase and enhanced affinity for estrogen receptors when compared to norendoxifen. The selectivity of 10 for aromatase versus other cytochrome P450 enzymes was also superior to norendoxifen. 4'-Hydroxynorendoxifen is therefore an interesting lead for further development to obtain new anticancer agents of potential value for the treatment of breast cancer. PMID:25751283

  11. Δ(9)-Tetrahydrocannabinol disrupts estrogen-signaling through up-regulation of estrogen receptor β (ERβ).

    PubMed

    Takeda, Shuso; Yoshida, Kazutaka; Nishimura, Hajime; Harada, Mari; Okajima, Shunsuke; Miyoshi, Hiroko; Okamoto, Yoshiko; Amamoto, Toshiaki; Watanabe, Kazuhito; Omiecinski, Curtis J; Aramaki, Hironori

    2013-07-15

    Δ(9)-Tetrahydrocannabinol (Δ(9)-THC) has been reported as possessing antiestrogenic activity, although the mechanisms underlying these effects are poorly delineated. In this study, we used the estrogen receptor α (ERα)-positive human breast cancer cell line, MCF-7, as an experimental model and showed that Δ(9)-THC exposures markedly suppresses 17β-estradiol (E2)- induced MCF-7 cell proliferation. We demonstrate that these effects result from Δ(9)-THC's ability to inhibit E2-liganded ERα activation. Mechanistically, the data obtained from biochemical analyses revealed that (i) Δ(9)-THC up-regulates ERβ, a repressor of ERα, inhibiting the expression of E2/ERα-regulated genes that promote cell growth and that (ii) Δ(9)-THC induction of ERβ modulates E2/ERα signaling in the absence of direct interaction with the E2 ligand binding site. Therefore, the data presented support the concept that Δ(9)-THC's antiestrogenic activities are mediated by the ERβ disruption of E2/ERα signaling.

  12. Estrogen Receptor β Activation Rapidly Modulates Male Sexual Motivation through the Transactivation of Metabotropic Glutamate Receptor 1a

    PubMed Central

    Seredynski, Aurore L.; Balthazart, Jacques; Ball, Gregory F.

    2015-01-01

    In addition to the transcriptional activity of their liganded nuclear receptors, estrogens, such as estradiol (E2), modulate cell functions, and consequently physiology and behavior, within minutes through membrane-initiated events. The membrane-associated receptors (mERs) underlying the acute effects of estrogens on behavior have mostly been documented in females where active estrogens are thought to be of ovarian origin. We determined here, by acute intracerebroventricular injections of specific agonists and antagonists, the type(s) of mERs that modulate rapid effects of brain-derived estrogens on sexual motivation in male Japanese quail. Brain aromatase blockade acutely inhibited sexual motivation. Diarylpropionitrile (DPN), an estrogen receptor β (ERβ)-specific agonist, and to a lesser extent 17α-estradiol, possibly acting through ER-X, prevented this effect. In contrast, drugs targeting ERα (PPT and MPP), GPR30 (G1 and G15), and the Gq-mER (STX) did not affect sexual motivation. The mGluR1a antagonist LY367385 significantly inhibited sexual motivation but mGluR2/3 and mGluR5 antagonists were ineffective. LY367385 also blocked the behavioral restoration induced by E2 or DPN, providing functional evidence that ERβ interacts with metabotropic glutamate receptor 1a (mGluR1a) signaling to acutely regulate male sexual motivation. Together these results show that ERβ plays a key role in sexual behavior regulation and the recently uncovered cooperation between mERs and mGluRs is functional in males where it mediates the acute effects of estrogens produced centrally in response to social stimuli. The presence of an ER–mGluR interaction in birds suggests that this mechanism emerged relatively early in vertebrate history and is well conserved. SIGNIFICANCE STATEMENT The membrane-associated receptors underlying the acute effects of estrogens on behavior have mostly been documented in females, where active estrogens are thought to be of ovarian origin. Using acute

  13. Estrogen Receptor β Activation Rapidly Modulates Male Sexual Motivation through the Transactivation of Metabotropic Glutamate Receptor 1a.

    PubMed

    Seredynski, Aurore L; Balthazart, Jacques; Ball, Gregory F; Cornil, Charlotte A

    2015-09-23

    In addition to the transcriptional activity of their liganded nuclear receptors, estrogens, such as estradiol (E2), modulate cell functions, and consequently physiology and behavior, within minutes through membrane-initiated events. The membrane-associated receptors (mERs) underlying the acute effects of estrogens on behavior have mostly been documented in females where active estrogens are thought to be of ovarian origin. We determined here, by acute intracerebroventricular injections of specific agonists and antagonists, the type(s) of mERs that modulate rapid effects of brain-derived estrogens on sexual motivation in male Japanese quail. Brain aromatase blockade acutely inhibited sexual motivation. Diarylpropionitrile (DPN), an estrogen receptor β (ERβ)-specific agonist, and to a lesser extent 17α-estradiol, possibly acting through ER-X, prevented this effect. In contrast, drugs targeting ERα (PPT and MPP), GPR30 (G1 and G15), and the Gq-mER (STX) did not affect sexual motivation. The mGluR1a antagonist LY367385 significantly inhibited sexual motivation but mGluR2/3 and mGluR5 antagonists were ineffective. LY367385 also blocked the behavioral restoration induced by E2 or DPN, providing functional evidence that ERβ interacts with metabotropic glutamate receptor 1a (mGluR1a) signaling to acutely regulate male sexual motivation. Together these results show that ERβ plays a key role in sexual behavior regulation and the recently uncovered cooperation between mERs and mGluRs is functional in males where it mediates the acute effects of estrogens produced centrally in response to social stimuli. The presence of an ER-mGluR interaction in birds suggests that this mechanism emerged relatively early in vertebrate history and is well conserved. Significance statement: The membrane-associated receptors underlying the acute effects of estrogens on behavior have mostly been documented in females, where active estrogens are thought to be of ovarian origin. Using acute

  14. Phytoestrogens and Mycoestrogens Induce Signature Structure Dynamics Changes on Estrogen Receptor α

    PubMed Central

    Chen, Xueyan; Uzuner, Ugur; Li, Man; Shi, Weibing; Yuan, Joshua S.; Dai, Susie Y.

    2016-01-01

    Endocrine disrupters include a broad spectrum of chemicals such as industrial chemicals, natural estrogens and androgens, synthetic estrogens and androgens. Phytoestrogens are widely present in diet and food supplements; mycoestrogens are frequently found in grains. As human beings and animals are commonly exposed to phytoestrogens and mycoestrogens in diet and environment, it is important to understand the potential beneficial or hazardous effects of estrogenic compounds. Many bioassays have been established to study the binding of estrogenic compounds with estrogen receptor (ER) and provided rich data in the literature. However, limited assays can offer structure information with regard to the ligand/ER complex. Our current study surveys the global structure dynamics changes for ERα ligand binding domain (LBD) when phytoestrogens and mycoestrogens bind. The assay is based on the structure dynamics information probed by hydrogen deuterium exchange mass spectrometry and offers a unique viewpoint to elucidate the mechanism how phytoestrogens and mycoestrogens interact with estrogen receptor. The cluster analysis based on the hydrogen deuterium exchange (HDX) assay data reveals a unique pattern when phytoestrogens and mycoestrogens bind with ERα LBD compared to that of estradiol and synthetic estrogen modulators. Our study highlights that structure dynamics could play an important role in the structure function relationship when endocrine disrupters interact with estrogen receptors. PMID:27589781

  15. Role of the Neddylation Enzyme Uba3, A New Estrogen Receptor Corepressor, in Breast Cancer

    DTIC Science & Technology

    2005-05-01

    expression of ERa in tumors with acquired resistance, such as disruptions in the NEDD8, CHIP or other ubiquitin or ubiquitin- associated / protein receptor...estrogen. Faseb J 18 :81-93 13. Fan M, Park A, Nephew KP. Interactions between estrogen receptor and the COOH terminus of the Hsp70- interacting protein ...responses. An attenuated transcrip- target proteins is primarily conferred by E3, regulation tional response has been associated with down-regula- of

  16. Comparative study on the in vitro/in vivo estrogenic potencies of 17beta-estradiol, estrone, 17alpha-ethynylestradiol and nonylphenol.

    PubMed

    Van den Belt, K; Berckmans, P; Vangenechten, C; Verheyen, R; Witters, H

    2004-02-10

    The estrogenic activity of compounds was evaluated in a comparative approach both with in vitro and in vivo assays. By comparing simultaneously obtained experimental data, we evaluated the differences in response sensitivity (by EC10) and concentration-response relationships (including EC50) in order to get an idea about the predictive value of in vitro assays for in vivo estrogenic potencies or effects in fish. Two human estrogen receptor-based assays, the MVLN-assay (transformed MCF-7 human breast cancer cell line) and the yeast estrogen screen (YES-screen) were used for the in vitro evaluation of the estrogenic potencies. An in vivo model with the female zebrafish (Danio rerio) with plasma vitellogenin (VTG) as a biomarker for exposure and the ovarian somatic index (OSI) as an effect endpoint was used for the in vivo work. Compounds tested were 17beta-estradiol (E2), estrone (E1), 17alpha-ethynylestradiol (EE2) and the alkylphenolic compound nonylphenol (NP). All compounds were found to be estrogenic in both in vitro assays and were able to induce VTG and to reduce the ovarian somatic index in female zebrafish. The MVLN-assay appeared up to 15 times more sensitive than the YES-screen. Concentration-response relationships, determined by EC10 and EC50 (concentration of test compound causing 10% or 50% effect compared to control) for VTG and OSI were of the same order of magnitude, indicating that VTG induction as an exposure biomarker can be predictive for effects on ovaries in females. We further demonstrated that for E1 and NP, the in vitro observed estrogenic potencies, based on EC50 values, were of the same order of magnitude as the in vivo estrogenic potencies. For EE2, a difference between in vitro and in vivo relative estrogenic potency was observed, being about 25 times more potent in vivo than could be expected based on the in vitro results. These experimental results showed the suitability of in vitro assays for screening purposes with qualitative

  17. Distribution of estrogen and progesterone receptors isoforms in endometrial cancer

    PubMed Central

    2014-01-01

    Background 70–80% of sporadic endometrial carcinomas are defined as endometrioid carcinoma (EC). Early-stage, well differentiated endometrial carcinomas usually retain expression of estrogen and progesterone receptors (ER and PR, respectively), as advanced stage, poorly differentiated tumors often lack one or both of these receptors. Well-described EC prognosis includes tumor characteristics, such as depth of myometrial invasion. Therefore, in the current study, we evaluated the expression profile of ER and PR isoforms, including ER-α, PR-A and PR–B, in correlation to EC tumor histological depth. Methods Using immunohistochemistry and image analysis software, the expression of ER-α, PR-A, PR–B and Ki67 was assessed in endometrial stroma and epithelial glands of superficial, deep and extra-tumoral sections of 15 paraffin embedded EC specimens, and compared to 5 biopsies of non-malignant endometrium. Results Expression of PR-A and ER-α was found to be lower in EC compared to nonmalignant tissue, as the stromal expression was dramatically reduced compared to epithelial cells. Expression ratios of both receptors were significantly high in superficial and deep portions of EC; in non-tumoral portion of EC were close to the ratios of nonmalignant endometrium. PR-B expression was low in epithelial glands of EC superficial and deep portions, and high in the extra-tumoral region. Elevated PR-B expression was found in stroma of EC, as well. Conclusions The ratio of ER-α and PR-A expression in the epithelial glands and the stroma of EC biopsies may serve as an additional parameter in the histological evaluation of EC tumor. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1155060506119016 PMID:24684970

  18. Cellular interactions uncouple beta-adrenergic receptors from adenylate cyclase.

    PubMed

    Ciment, G; de Vellis, J

    1978-11-17

    C6 glioma cells and B104 neuroblastoma cells both possess adenylate cyclase activity, but only C6 cells have beta-adrenergic receptors. However, when cocultured with B104 cells, C6 cells show a marked decrease in their ability to accumulate adenosine 3', 5'-monophosphate upon stimulation with beta receptor agonists. Since both beta receptors and cholera toxin-stimulated adenylate cyclase activities are present in C6/B104 cocultures, we conclude that the beta receptor/adenylate cyclase transduction mechanism in cocultured C6 cells is uncoupled.

  19. Ontogeny of cells containing estrogen receptor-like immunoreactivity in the Brazilian opossum brain.

    PubMed

    Fox, C A; Ross, L R; Jacobson, C D

    1991-11-19

    In this study, we have used the Brazilian short-tailed opossum (Monodelphis domestica) as a model to study the ontogeny of estrogen receptors in the mammalian brain. Monodelphis is a small, pouchless marsupial which breeds well under laboratory conditions and whose young are born in an immature sexually undifferentiated state. The Abbott H222 monoclonal rat estrogen receptor antibody (gift of Abbott Laboratories) was utilized in an indirect immunohistochemical procedure to detect estrogen receptors in developing opossum brains. Estrogen receptors were first expressed in the dorsomedial and ventromedial hypothalamus of the opossum 10 days after birth (10PN). Most regions that contained estrogen receptor-like immunoreactivity (ER LI) in the adult opossum contained ER LI at 15 PN. These areas include the lateral septum, medial preoptic area, bed nucleus of the stria terminalis, periventricular preoptic area and hypothalamus, amygdala, dorsomedial and ventromedial hypothalamic nuclei, arcuate nucleus, ventral premammillary nucleus, and the midbrain central grey. The number of cells that contain ER LI increased through 60PN in all regions that will contain ER LI in the adult opossum. These results indicate that estrogen receptors are present in early development of the Monodelphis brain and may mark the beginning of a critical period for sexual differentiation of the opossum brain.

  20. Phorbol ester induced phosphorylation of the estrogen receptor in intact MCF-7 human breast cancer cells

    SciTech Connect

    Knabbe, C.; Lippman, M.E.; Greene, G.L.; Dickson, R.B.

    1986-05-01

    Recent studies with a variety of cellular receptors have shown that phorbol ester induced phosphorylation modulates ligand binding and function. In this study the authors present direct evidence that the estrogen receptor in MCF-7 human breast cancer cells is a phosphoprotein whose phosphorylation state can be enhanced specifically by phorbol-12-myristate-13-acetate (PMA). Cells were cultured to 6h in the presence of (/sup 32/P)-orthophosphate. Whole cell extracts were immunoprecipitated with a monoclonal antibody (D58) against the estrogen receptor and subjected to SDS-polyacrylamide electrophoresis. Autoradiography showed a specific band in the region of 60-62 kDa which was significantly increased in preparations from PMA treated cells. Phospho-amino acid analysis demonstrated specific phosphorylation of serine and threonine residues. Cholera toxin or forskolin did not change the phosphorylation state of this protein. In a parallel binding analysis PMA led to a rapid decrease of estrogen binding sites. The estrogen induction of both progesterone receptors and growth in semisolid medium was blocked by PMA, whereas the estrogen induction of the 8kDa protein corresponding to the ps2 gene product and of the 52 kDa protein was not affected. In conclusion, phorbol esters can induce phosphorylation of the estrogen receptor. This process may be associated with the inactivation of certain receptor functions.

  1. Estrogen receptor alpha is required for mammary development and the induction of mammary hyperplasia and epigenetic alterations in the aromatase transgenic mice.

    PubMed

    Tekmal, Rajeshwar Rao; Liu, Ya-Guang; Nair, Hareesh B; Jones, Jeremy; Perla, Rao P; Lubahn, Dennis B; Korach, Kenneth S; Kirma, Nameer

    2005-05-01

    Aromatase transgenic mice exhibit hyperplastic and dysplastic changes, attesting to the importance of local estrogen in breast carcinogenesis. These mice also show increased levels of the estrogen receptor alpha and beta (ERalpha, ERbeta) suggesting that this receptor may play an important role in the initiation of estrogen-mediated mammary hyperplasia observed in these mice. To address the specific role of ERalpha in the mammary development and in the induction of estrogen-mediated hyperplasia in aromatase transgenic mice, we have generated MMTV-aromatase x ERalpha knockout cross (referred as aromatase/ERKO). Even though ERbeta is expressed in aromatase/ERKO mice, lack of ERalpha leads to impaired mammary growth in these mice. The data suggest that ERalpha plays an important role in the mammary gland development as well as in the induction of mammary hyperplasia in aromatase transgenic mice. Lack of ERalpha expression in the aromatase/ERKO mice resulted in a decrease in the expression of Cyclin D1, PCNA and TGFbeta relative to the aromatase parental strain. The studies involving aromatase/ERKO mice show that lack of ERalpha results in impaired mammary development even in the presence of continuous tissue estrogen, suggesting estrogen/ERalpha-mediated actions are critical for mammary development and carcinogenesis.

  2. LSD1 engages a corepressor complex for the activation of the estrogen receptor α by estrogen and cAMP

    PubMed Central

    Bennesch, Marcela A.; Segala, Gregory; Wider, Diana; Picard, Didier

    2016-01-01

    The estrogen receptor α (ERα) is a transcription factor that can be directly activated by estrogen or indirectly by other signaling pathways. We previously reported that activation of the unliganded ERα by cAMP is mediated by phosphorylation of the transcriptional coactivator CARM1 by protein kinase A (PKA), allowing CARM1 to bind ERα directly. This being insufficient by itself to activate ERα, we looked for additional factors and identified the histone H3 demethylase LSD1 as a substrate of PKA and an important mediator of this signaling crosstalk as well as of the response to estrogen. Surprisingly, ERα engages not only LSD1, but its partners of the CoREST corepressor complex and the molecular chaperone Hsp90. The recruitment of Hsp90 to promote ERα transcriptional activity runs against the steroid receptor paradigm and suggests that it might be involved as an assembly factor or scaffold. In a breast cancer cell line, which is resistant to the anti-estrogen tamoxifen because of constitutively activated PKA, some interactions are constitutive and drug combinations partially rescue tamoxifen sensitivity. In ERα-positive breast cancer patients, high expression of the genes encoding some of these factors correlates with poor prognosis. Thus, these mechanisms might contribute to ERα-driven breast cancer. PMID:27325688

  3. Laccase-mediated transformations of endocrine disrupting chemicals abolish binding affinities to estrogen receptors and their estrogenic activity in zebrafish.

    PubMed

    Torres-Duarte, Cristina; Viana, María Teresa; Vazquez-Duhalt, Rafael

    2012-10-01

    Endocrine disrupting chemicals (EDCs) are known to mainly affect aquatic organisms, producing negative effects in aquaculture. Transformation of the estrogenic compounds 17β-estradiol (E2), bisphenol-A (BPA), nonylphenol (NP), and triclosan (TCS) by laccase of Coriolopsis gallica was studied. Laccase is able to efficiently transform them into polymers. The estrogenic activity of the EDCs and their laccase transformation products was evaluated in vitro as their affinity for the human estrogen receptor alpha (hERα) and for the ligand binding domain of zebrafish (Danio rerio) estrogen receptor alpha (zfERαLBD). E2, BPA, NP, and TCS showed higher affinity for the zfERαLBD than for hERα. After laccase treatment, no affinity was found, except a marginal affinity of E2 products for the zfERαLBD. Endocrine disruption studies in vivo on zebrafish were performed using the induction of vitellogenin 1 as a biomarker (VTG1 mRNA levels). The use of enzymatic bioreactors, containing immobilized laccase, efficiently eliminates the endocrine activity of BPA and TCS, and significantly reduces the effects of E2. The potential use of enzymatic reactors to eliminate the endocrine activity of EDCs in supply water for aquaculture is discussed.

  4. Body Mass Index is Associated with Gene Methylation in Estrogen Receptor-Positive Breast Tumors

    PubMed Central

    Hair, Brionna Y.; Troester, Melissa A.; Edmiston, Sharon N.; Parrish, Eloise A.; Robinson, Whitney R.; Wu, Michael C.; Olshan, Andrew F.; Swift-Scanlan, Theresa; Conway, Kathleen

    2015-01-01

    Background Although obesity is associated with breast cancer incidence and prognosis, the underlying mechanisms are poorly understood. Identification of obesity-associated epigenetic changes in breast tissue may advance mechanistic understanding of breast cancer initiation and progression. The goal of this study, therefore, was to investigate associations between obesity and gene methylation in breast tumors. Methods Using the Illumina GoldenGate Cancer I Panel, we estimated the association between body mass index (BMI) and gene methylation in 345 breast tumor samples from Phase I of the Carolina Breast Cancer Study, a population based case-control study. Multivariable linear regression was used to identify sites that were differentially methylated by BMI. Stratification by tumor estrogen receptor status was also conducted. Results In the majority of the 935 probes analyzed (87%), the average beta value increased with obesity (BMI ≥ 30). Obesity was significantly associated with differential methylation (false discovery rate q-value < 0.05) in just 2 gene loci in breast tumor tissue overall and in 21 loci among estrogen receptor (ER)-positive tumors. Obesity was associated with methylation of genes that function in immune response, cell growth, and DNA repair. Conclusions Obesity is associated with altered methylation overall, and with hypermethylation among ER-positive tumors in particular, suggesting that obesity may influence the methylation of genes with known relevance to cancer. Some of these differences in methylation by obese status may influences levels of gene expression within breast cells. Impact If our results are validated, obesity-associated methylation sites could serve as targets for prevention and treatment research. PMID:25583948

  5. Receptors for leptin and estrogen in the subcommissural organ of rabbits are differentially modulated by fasting.

    PubMed

    Dall'Aglio, Cecilia; Ceccarelli, Piero; Pascucci, Luisa; Brecchia, Gabriele; Boiti, Cristiano

    2006-12-08

    In rabbits, the fasting-dependent reduction of LH secretion is likely mediated by leptin and estrogens via receptors in the brain. For the first time, using immunohistochemistry, the presence and regulation of receptors for leptin (Ob-R) and estradiol-17beta subtype alpha (ERalpha) were studied in the subcommissural organ (SCO) of rabbits, which were fed either ad libitum (control) or fasted for 48 h (treated) to verify whether this brain structure is a potential site of integration for metabolism and reproduction. In control rabbits, the cytoplasm of glial cells lining the SCO evidenced strong Ob-R immunoreactivity, whereas both ependymal and hypendymal cells of this glandular-like structure were negative. The Ob-R positive glial cells were identified as fibrous astrocytes using the phosphotungstic acid-hematoxylin histochemical (PTAH) and glial fibrillary acidic protein (GFAP) immunohistochemical techniques. ERalpha immunoreactive nuclei were detectable exclusively in the specialized cells forming the SCO, whereas surrounding astrocytes and neurons were negative. Compared to controls, in fasted rabbits, the staining of Ob-R immunoreaction was reduced in the cytoplasm of positive astrocytes, but greatly enhanced in plasma membranes, whereas the number of ERalpha immunoreactive SCO cells was increased (13.2+/-2.7 vs. 5.2+/-2.0, P<0.01). Ependymal cells lining the third ventricle were negative for both Ob-R and ERalpha. Our results indicate, although indirectly, that the SCO, together with the astrocytes in close contact with this structure, is a likely target for nutritional and gonadal signals carried by leptin and estrogens, suggesting that these specialized glial cells may regulate reproduction and metabolism through mechanisms still unknown.

  6. Estrogen Receptor Alpha G525L Knock-In Mice

    DTIC Science & Technology

    2007-03-01

    response to endogenous estrogens. These female estrogen non-responsive ERα knock-in (ENERKI) mice had immature and hypoplastic uterine and vaginal ...developing mice as well as in adult animals with genetically induced mammary cancers through PPT administration or withdrawal. 15. SUBJECT TERMS estrogen...is a crucial therapeutic target for hormone dependent breast cancers . More effective treatment and prevention strategies are likely to emerge from

  7. Alteration in Nuclear Factor-KappaB Pathway and Functionality of Estrogen via Receptors Promote Neuroinflammation in Frontal Cortex after 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine Treatment

    PubMed Central

    Mitra, Soham; Ghosh, Nabanita; Sinha, Priyobrata; Chakrabarti, Nilkanta; Bhattacharyya, Arindam

    2015-01-01

    The MPTP mediated neurodegeneration in substantia nigra has been well studied, but not the status of frontal cortex. The novelty of the present study is to explore the sex difference of frontal cortex during MPTP intoxication and to investigate the role of estrogen and its receptors in presence of glial cells in a time chase experiment; to identify which pathway of NF-kappaB exist to proceed the neuroinflammation; to investigate the estrogen binding with its nuclear or cytosolic receptors and whether any direct relation exists between estrogen receptor (ER) -beta and NF-kappaB molecules p65 and RelB. The progression of neurodegeneration occurred with the association of glial cells and functional (via its nuclear and cytosolic receptors) estrogen level. Both the canonical and/or non canonical pathways of NF-kappaB exist in frontal cortex of both the sexes after MPTP treatment. The homodimeric or heterodimeric form of ER-beta binds with NF-kappaB molecules p65 and RelB differently, but the canonical or non canonical pathways of NF-kappaB molecules could not be stopped or may be promoted. The changes in the molecular and cellular pattern in frontal cortex of both sexes during MPTP intoxication depends on the estrogen function via its nuclear or cytosolic estrogen receptors. PMID:26365888

  8. Immunohistochemical profiling of estrogen-related receptor gamma in rat brain and colocalization with estrogen receptor alpha in the preoptic area.

    PubMed

    Tanida, Takashi; Matsuda, Ken Ichi; Yamada, Shunji; Kawata, Mitsuhiro; Tanaka, Masaki

    2017-03-15

    Estrogen-related receptor (ERR) is a member of the nuclear receptor superfamily that has strong homology with estrogen receptor (ER) α. Despite the lack of endogenous ligands, ERR serves as transcription factors through their constitutively active structure with or without interaction with ERα. Among the three subtypes of ERR (α, β, and γ), ERRγ is highly expressed in brain, but the distribution of ERRγ is poorly characterized. Therefore, we investigated ERRγ immunoreactivity throughout the rostro-caudal axis in rat brain. Immunohistochemistry revealed localization of ERRγ protein in the cell nucleus, and a ubiquitous distribution of ERRγ in brain regions including the olfactory bulb, cerebrum, brain stem, and cerebellum. Selective intense immunoreactivity was observed in the reticular thalamic nucleus, zona incerta, circular nucleus, interpeduncular nucleus, pontine nucleus, and parasolitary nucleus. Most ERRγ-immunoreactive (ir) regions were also positive for ERα and/or ERβ, which suggests that ERRγ is involved in modulation of estrogen signaling in adult rat brain. Double immunofluorescence demonstrated colocalization of ERRγ with ERα within the anteroventral periventricular nucleus of the preoptic area (AVPV) and medial preoptic nucleus (MPO), which are major target sites for estrogen action. The results of this study suggest that ERRγ function in the brain is affected by estrogens through an interaction with ERα. The findings also provide basic information on brain region-specific ERRγ function.

  9. Estrogen-related receptor {alpha} modulates the expression of adipogenesis-related genes during adipocyte differentiation

    SciTech Connect

    Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Yagi, Ken; Okazaki, Yasushi; Inoue, Satoshi . E-mail: INOUE-GER@h.u-tokyo.ac.jp

    2007-07-06

    Estrogen-related receptor {alpha} (ERR{alpha}) is an orphan nuclear receptor that regulates cellular energy metabolism by modulating gene expression involved in fatty acid oxidation and mitochondrial biogenesis in brown adipose tissue. However, the physiological role of ERR{alpha} in adipogenesis and white adipose tissue development has not been well studied. Here, we show that ERR{alpha} and ERR{alpha}-related transcriptional coactivators, peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) coactivator-1{alpha} (PGC-1{alpha}) and PGC-1{beta}, can be up-regulated in 3T3-L1 preadipocytes at mRNA levels under the adipogenic differentiation condition including the inducer of cAMP, glucocorticoid, and insulin. Gene knockdown by ERR{alpha}-specific siRNA results in mRNA down-regulation of fatty acid binding protein 4, PPAR{gamma}, and PGC-1{alpha} in 3T3-L1 cells in the adipogenesis medium. ERR{alpha} and PGC-1{beta} mRNA expression can be also up-regulated in another preadipocyte lineage DFAT-D1 cells and a pluripotent mesenchymal cell line C3H10T1/2 under the differentiation condition. Furthermore, stable expression of ERR{alpha} in 3T3-L1 cells up-regulates adipogenic marker genes and promotes triglyceride accumulation during 3T3-L1 differentiation. These results suggest that ERR{alpha} may play a critical role in adipocyte differentiation by modulating the expression of various adipogenesis-related genes.

  10. Transformation of the rat uterine estrogen receptor after partial purification.

    PubMed

    Nielsen, S; Notides, A C

    1975-02-13

    Warming crude ratuterine cytosol after the addition of [3H] estradiol accelerates the association of the 4-S estrogen-binding protein with a second macromolecule, resulting in the formation of the 5-S estrogen-binding protein. To determine whether the 5-S estrogen-binding protein consists of two similar or dissimilar subunits, uterine cytosol was subjected to a number of fractionation procedures that separate macromolecules by solubility, molecular gel sieving, sedimentation rate, ionic charge, and heat lability. Following each of these methods, the fraction containing the 4-S estrogen-binding protein was incubated at 28 degrees C; each of the these 4-S estrogen-binding protein-containing fractions retained its capacity to completely transform to the 5-S estrogen-binding protein. In samples subjected to partial purification procedures, it was necessary that the buffer contain 40 mM Tris, 60 mM Tris, 60 mM KC1, 1-10 MM dithiothreitol, and 1 M urea at pH 7.4, in order to accomplish the 4-S to 5-S estrogen-binding protein transformation at 25 degrees C. Formation of the 5-S estrogen-binding protein requires association of the 4-Estrogen-binding protein with a molecule identical to or very similar to itself.

  11. Estrogen receptor and progesterone receptor synthesis and degradation in target cells

    SciTech Connect

    Nardulli, A.M.

    1987-01-01

    It was the intent of this study to determine the turnover of the estrogen receptor (ER) and progesterone receptors (PR) in rat uterine and human breast cancer cells, respectively, and to examine the effect of estrogen and progestin on PR levels. The rates of synthesis and degradation of ER were determined in rat uterine cells in vitro and in vivo. The affinity labeling antiestrogen, (/sup 3/H)tamoxifen aziridine, was used in pulse chase experiments to show that the 65,000 molecular weight ER has a half-life of 3-4h in primary cultures of rat uterine cells in vitro and in the intact rat uterus in vivo. Density shift analyses using dense (/sup 15/N, /sup 13/C, /sup 2/H) amino acid incorporation corroborate the rapid turnover of ER in rat uterine cell cultures. The regulation of PR by progestins in T47D human breast cancer cells was examined using density shift-dense amino acid incorporation. When T47D cells, which normally maintain high PR levels, are exposed to progestin (R5020), PR levels decline. Receptor half-life, which is 21h in control cells, is reduced to 6h when cells are exposed to 20 nM (/sup 3/H)R5020. In addition, PR synthesis rate declines exponentially following R5020 exposure. The reduction in receptor level is thus due to dramatic increases in PR degradation as well as marked decreases in PR synthesis.

  12. A unique downstream estrogen responsive unit mediates estrogen induction of proteinase inhibitor-9, a cellular inhibitor of IL-1beta- converting enzyme (caspase 1).

    PubMed

    Krieg, S A; Krieg, A J; Shapiro, D J

    2001-11-01

    Recently, proteinase inhibitor 9 (PI-9) was identified as the first endogenous inhibitor of caspase 1 (IL-1beta-converting enzyme). The regulation of PI-9 expression, therefore, has great importance in the control of inflammatory processes. We reported that PI-9 mRNA and protein are rapidly and directly induced by estrogen in human liver cells. Using transient transfections to assay PI-9 promoter truncations and mutations, we demonstrate that this strong estrogen induction is mediated by a unique downstream estrogen responsive unit (ERU) approximately 200 nucleotides downstream of the transcription start site. Using primers flanking the ERU in chromatin immunoprecipitation assays, we demonstrate estrogen-dependent binding of ER to the cellular PI-9 promoter. The ERU consists of an imperfect estrogen response element (ERE) palindrome immediately adjacent to a direct repeat containing two consensus ERE half-sites separated by 13 nucleotides (DR13). In transient transfections, all four of the ERE half-sites in the imperfect ERE and in the DR13 were important for estrogen inducibility. Transfected chicken ovalbumin upstream transcription factor I and II down-regulated estrogen-mediated expression from the ERU. EMSAs using purified recombinant human ERalpha demonstrate high-affinity binding of two ER complexes to the ERU. Further EMSAs showed that one ER dimer binds to an isolated DR13, supporting the view that one ER dimer binds to the imperfect ERE and one ER dimer binds to DR13. Deoxyribonuclease I footprinting showed that purified ER protected all four of the half-sites in the ERU. Our finding that a direct repeat can function with an imperfect ERE palindrome to confer estrogen inducibility on a native gene extends the repertoire of DNA sequences able to function as EREs.

  13. The role of allelic variation in estrogen receptor genes and major depression in the Nurses Health Study

    PubMed Central

    Keyes, K.; Agnew-Blais, J.; Roberts, A.; Hamilton, A.; De Vivo, I.; Ranu, H.; Koenen, K.

    2015-01-01

    Purpose The role of exogenous and endogenous sex hormones in the etiology of depression remains elusive, in part because sex hormone variation is often correlated with behaviors, life stage changes, and other factors that may influence depression. Estrogen receptor alpha (ESR1) and beta (ESR2) are known to regulate gene expression and estrogen response in areas of the brain associated with major depression and are unlikely to be correlated with exogenous factors that may influence depression. Methods We examined whether functional polymorphisms in these genes are associated with lifetime major depression and chronic major depression among a sample of women from the Nurses’ Health Study II (N=2,576). DSM-IV depressive disorder symptoms were assessed by structured interview in 2007. Genotyping was performed on DNA extracted from blood using Taq-man. Results Women with the AA alleles of ESR2 RS4986938 had the higher prevalence of lifetime major depression than women with other allele frequencies (36.7% for those with AA versus 28.5% with GA and 29.1% with GG, p=0.02) and chronic major depression (14.7% for those with AA versus 9.3% with GA and 9.1 % with GG, p=0.01). History of post-menopausal hormone (PMH) use modified the association of ESR1 polymorphism RS2234693 with any lifetime depression; specifically, those with the TT allele had the highest risk of lifetime depression among PMH users, and the lowest risk of depression among non-PMH users (p-value for interaction=0.02). Further, carriers of the AA alleles in ESR1 polymorphism RS9340799 had increased prevalence of lifetime major depression only among lifetime PMH-users (p=0.007). Conclusions Our findings support the hypothesis that estrogen receptor polymorphisms influence risk for major depression; the role of estrogen receptors and other sex steroid-related genetic factors may provide unique insights into etiology. PMID:26169989

  14. CTCF modulates Estrogen Receptor function through specific chromatin and nuclear matrix interactions

    PubMed Central

    Fiorito, Elisa; Sharma, Yogita; Gilfillan, Siv; Wang, Shixiong; Singh, Sachin Kumar; Satheesh, Somisetty V.; Katika, Madhumohan R.; Urbanucci, Alfonso; Thiede, Bernd; Mills, Ian G.; Hurtado, Antoni

    2016-01-01

    Enhancer regions and transcription start sites of estrogen-target regulated genes are connected by means of Estrogen Receptor long-range chromatin interactions. Yet, the complete molecular mechanisms controlling the transcriptional output of engaged enhancers and subsequent activation of coding genes remain elusive. Here, we report that CTCF binding to enhancer RNAs is enriched when breast cancer cells are stimulated with estrogen. CTCF binding to enhancer regions results in modulation of estrogen-induced gene transcription by preventing Estrogen Receptor chromatin binding and by hindering the formation of additional enhancer-promoter ER looping. Furthermore, the depletion of CTCF facilitates the expression of target genes associated with cell division and increases the rate of breast cancer cell proliferation. We have also uncovered a genomic network connecting loci enriched in cell cycle regulator genes to nuclear lamina that mediates the CTCF function. The nuclear lamina and chromatin interactions are regulated by estrogen-ER. We have observed that the chromatin loops formed when cells are treated with estrogen establish contacts with the nuclear lamina. Once there, the portion of CTCF associated with the nuclear lamina interacts with enhancer regions, limiting the formation of ER loops and the induction of genes present in the loop. Collectively, our results reveal an important, unanticipated interplay between CTCF and nuclear lamina to control the transcription of ER target genes, which has great implications in the rate of growth of breast cancer cells. PMID:27638884

  15. Importance of Estrogenic Signaling and Its Mediated Receptors in Prostate Cancer

    PubMed Central

    Lau, Kin-Mang; To, Ka-Fai

    2016-01-01

    Prostate cancer (PCa) treatment was first established by Huggins and Hodges in 1941, primarily described as androgen deprivation via interference of testicular androgen production. The disease remains incurable with relapse of hormone-refractory cancer after treatments. Epidemiological and clinical studies disclosed the importance of estrogens in PCa. Discovery of estrogen receptor ERβ prompted direct estrogenic actions, in conjunction with ERα, on PCa cells. Mechanistically, ERs upon ligand binding transactivate target genes at consensus genomic sites via interactions with various transcriptional co-regulators to mold estrogenic signaling. With animal models, Noble revealed estrogen dependencies of PCa, providing insight into potential uses of antiestrogens in the treatment. Subsequently, various clinical trials were conducted and molecular and functional consequences of antiestrogen treatment in PCa were delineated. Besides, estrogens can also trigger rapid non-genomic signaling responses initiated at the plasma membrane, at least partially via an orphan G-protein-coupled receptor GPR30. Activation of GPR30 significantly inhibited in vitro and in vivo PCa cell growth and the underlying mechanism was elucidated. Currently, molecular networks of estrogenic and antiestrogenic signaling via ERα, ERβ and GPR30 in PCa have not been fully deciphered. This crucial information could be beneficial to further developments of effective estrogen- and antiestrogen-based therapy for PCa patients. PMID:27589731

  16. Estrogen receptor agonists for attenuation of neuroinflammation and neurodegeneration

    PubMed Central

    Chakrabarti, Mrinmay; Haque, Azizul; Banik, Naren L.; Nagarkatti, Prakash; Nagarkatti, Mitzi; Ray, Swapan K.

    2014-01-01

    Recent results from laboratory investigations and clinical trials indicate important roles for estrogen receptor (ER) agonists in protecting the central nervous system (CNS) from noxious consequences of neuroinflammation and neurodegeneration. Neurodegenerative processes in several CNS disorders including spinal cord injury (SCI), multiple sclerosis (MS), Parkinson's disease (PD), and Alzheimer's disease (AD) are associated with activation of microglia and astrocytes, which drive the resident neuroinflammatory response. During neurodegenerative processes, activated microglia and astrocytes cause deleterious effects on surrounding neurons. The inhibitory activity of ER agonists on microglia activation might be a beneficial therapeutic option for delaying the onset or progression of neurodegenerative injuries and diseases. Recent studies suggest that ER agonists can provide neuroprotection by modulation of cell survival mechanisms, synaptic reorganization, regenerative responses to axonal injury, and neurogenesis process. The anti-inflammatory and neuroprotective actions of ER agonists are mediated mainly via two ERs known as ERα and ERβ. Although some studies have suggested that ER agonists may be deleterious to some neuronal populations, the potential clinical benefits of ER agonists for augmenting cognitive function may triumph over the associated side effects. Also, understanding the modulatory activities of ER agonists on inflammatory pathways will possibly lead to the development of selective anti-inflammatory molecules with neuroprotective roles in different CNS disorders such as SCI, MS, PD, and AD in humans. Future studies should be concentrated on finding the most plausible molecular pathways for enhancing protective functions of ER agonists in treating neuroinflammatory and neurodegenerative injuries and diseases in the CNS. PMID:25245209

  17. Estrogen receptors regulate innate immune cells and signaling pathways.

    PubMed

    Kovats, Susan

    2015-04-01

    Humans show strong sex differences in immunity to infection and autoimmunity, suggesting sex hormones modulate immune responses. Indeed, receptors for estrogens (ERs) regulate cells and pathways in the innate and adaptive immune system, as well as immune cell development. ERs are ligand-dependent transcription factors that mediate long-range chromatin interactions and form complexes at gene regulatory elements, thus promoting epigenetic changes and transcription. ERs also participate in membrane-initiated steroid signaling to generate rapid responses. Estradiol and ER activity show profound dose- and context-dependent effects on innate immune signaling pathways and myeloid cell development. While estradiol most often promotes the production of type I interferon, innate pathways leading to pro-inflammatory cytokine production may be enhanced or dampened by ER activity. Regulation of innate immune cells and signaling by ERs may contribute to the reported sex differences in innate immune pathways. Here we review the recent literature and highlight several molecular mechanisms by which ERs regulate the development or functional responses of innate immune cells.

  18. Histone Deacetylase Inhibitors Equipped with Estrogen Receptor Modulation Activity

    PubMed Central

    Gryder, Berkley E.; Rood, Michael K.; Johnson, Kenyetta A.; Patil, Vishal; Raftery, Eric D.; Yao, Li-Pan D.; Rice, Marcie; Azizi, Bahareh; Doyle, Donald F.; Oyelere, Adegboyega K.

    2013-01-01

    We described a set of novel histone deacetylase inhibitors (HDACi) equipped with either an antagonist or an agonist of the estrogen receptor (ER) to confer selective activity against breast cancers. These bifunctional compounds potently inhibit HDAC at nanomolar concentrations, and either agonize or antagonize ERα and ERβ. The ER antagonist activities of tamoxifen-HDACi conjugates (Tam-HDACi) are nearly identical to those of tamoxifen. Conversely, ethynyl-estradiol HDACi conjugates (EED-HDACi) have attenuated ER agonist activities relative to the parent ethynyl-estradiol. In silico docking analysis provides structural basis for the trends of ER agonism/antagonism and ER subtype selectivity. Excitingly, lead Tam-HDACi conjugates show anticancer activity that is selectively more potent against MCF-7 (ERα positive breast) compared to MDA-MB-231 (triple negative breast cancer), DU145 (prostate cancer) or Vero (non-cancerous cell line). This dual-targeting approach illustrates the utility of designing small molecules with an emphasis on cell-type selectivity, not merely improved potency, working towards a higher therapeutic index at the earliest stages of drug development. PMID:23786452

  19. Urethral dysfunction in female mice with estrogen receptor β deficiency.

    PubMed

    Chen, Yung-Hsiang; Chen, Chao-Jung; Yeh, Shuyuan; Lin, Yu-Ning; Wu, Yang-Chang; Hsieh, Wen-Tsong; Wu, Bor-Tsang; Ma, Wen-Lung; Chen, Wen-Chi; Chang, Chawnshang; Chen, Huey-Yi

    2014-01-01

    Estrogen has various regulatory functions in the growth, development, and differentiation of the female urogenital system. This study investigated the roles of ERβ in stress urinary incontinence (SUI). Wild-type (ERβ(+/+)) and knockout (ERβ(-/-)) female mice were generated (aged 6-8 weeks, n = 6) and urethral function and protein expression were measured. Leak point pressures (LPP) and maximum urethral closure pressure (MUCP) were assessed in mice under urethane anesthesia. After the measurements, the urethras were removed for proteomic analysis using label-free quantitative proteomics by nano-liquid chromatography-mass spectrometry (LC-MS/MS) analysis. The interaction between these proteins was further analysed using MetaCore. Lastly, Western blot was used to confirm the candidate proteins. Compared with the ERβ(+/+) group, the LPP and MUCP values of the ERβ(-/-) group were significantly decreased. Additionally, we identified 85 differentially expressed proteins in the urethra of ERβ(-/-) female mice; 57 proteins were up-regulated and 28 were down-regulated. The majority of the ERβ knockout-modified proteins were involved in cell-matrix adhesion, metabolism, immune response, signal transduction, nuclear receptor translational regelation, and muscle contraction and development. Western blot confirmed the up-regulation of myosin and collagen in urethra. By contrast, elastin was down-regulated in the ERβ(-/-) mice. This study is the first study to estimate protein expression changes in urethras from ERβ(-/-) female mice. These changes could be related to the molecular mechanism of ERβ in SUI.

  20. Estrogen receptor modulatory effects of germinated brown rice bioactives in the uterus of rats through the regulation of estrogen-induced genes

    PubMed Central

    Muhammad, Sani Ismaila; Maznah, Ismail; Mahmud, Rozi Bint; Saeed, Mohammed Ibrahim; Imam, Mustapha Umar; Ishaka, Aminu

    2013-01-01

    Purpose The expression of genes regulated by estrogen in the uterus was studied in ovariectomized (OVX) rats treated with germinated brown rice (GBR) bioactives, and compared to Remifemin or estrogen at different doses to identify the regulation of these genes in the uterus and their molecular mechanisms. Methods Rats were treated orally with GBR bioactives (phenolics), acylated steryl glucosides (ASG), γ-amino butyric acid (GABA), and γ-oryzanol (ORZ) at 100 and 200 mg/kg, Remifemin (REM) at 10 mg/kg and 20 mg/kg, or estrogen (EST) at 0.2 mg/kg. Ribonucleic acid (RNA) was extracted from the uterus, and messenger (m)RNA expression of selected genes encoding estrogen receptor-beta (ER-β), calcium-binding protein (CaBP9k), complement protein (C3), heat shock protein 70 kDa (HSP70), and interleukin (IL)-4 receptor were quantified. Similarly, serum steroid hormone concentration was monitored at 2, 4, and 8 weeks after treatments. ER-β antibody binding to the uterus sections was also studied using immunohistochemistry. Results The group treated with EST (0.2 mg/kg) upregulated ER-β, C3, and IL-4 receptor genes compared to other groups (P<0.001). GBR phenolics (200 mg/kg) treatment upregulated the ER-β gene almost to the level of the sham non-treated group. The CaBP9k gene showed upregulation in groups treated with ASG (200 mg/kg), EST (0.2 mg/kg), and ORZ (200 mg/kg) (P<0.05). Estrogen levels increased in groups treated with EST, ASG, and ORZ (200 mg/kg) compared to the OVX untreated group (P<0.05), and there was a slight non-significant decrease (P>0.05) in the progesterone levels in the OVX untreated group compared to the sham and other treated groups. There was a significant increase at 8 weeks in the level of FSH (P<0.05) in the treated groups compared to the OVX untreated group. There was no significant difference (P>0.05) in serum luteinizing hormone (LH) between the OVX untreated group and other groups. The sham and GBR phenolics treated group showed ER

  1. Definition of the molecular basis for estrogen receptor-related receptor-alpha-cofactor interactions.

    PubMed

    Gaillard, Stéphanie; Dwyer, Mary A; McDonnell, Donald P

    2007-01-01

    Estrogen receptor-related receptor-alpha (ERRalpha) is an orphan nuclear receptor that does not appear to require a classical small molecule ligand to facilitate its interaction with coactivators and/or hormone response elements within target genes. Instead, the apo-receptor is capable of interacting in a constitutive manner with coactivators that stimulate transcription by acting as protein ligands. We have screened combinatorial phage libraries for peptides that selectively interact with ERRalpha to probe the architecture of the ERRalpha-coactivator pocket. In this manner, we have uncovered a fundamental difference in the mechanism by which this receptor interacts with peroxisome proliferator-activated receptor-gamma coactivator-1alpha, as compared with members of the steroid receptor coactivator subfamily of coactivators. Our findings suggest that it may be possible to develop ERRalpha ligands that exhibit different pharmacological activities as a consequence of their ability to differentially regulate coactivator recruitment. In addition, these findings have implications beyond ERRalpha because they suggest that subtle alterations in the structure of the activation function-2 pocket within any nuclear receptor may enable differential recruitment of coactivators, an observation of notable pharmaceutical importance.

  2. G-protein Coupled Estrogen Receptor, Estrogen Receptor α, and Progesterone Receptor Immunohistochemistry in the Hypothalamus of Aging Female Rhesus Macaques Given Long-Term Estradiol Treatment

    PubMed Central

    NAUGLE, MICHELLE M.; NGUYEN, LONG T.; MERCERON, TYLER K.; FILARDO, EDWARD; JANSSEN, WILLIAM G.M.; MORRISON, JOHN H.; RAPP, PETER R.; GORE, ANDREA C.

    2014-01-01

    Steroid hormone receptors are widely and heterogeneously expressed in the brain, and are regulated by age and gonadal hormones. Our goal was to quantify effects of aging, long-term estradiol (E2) treatment, and their interactions, on expression of G protein-coupled estrogen receptor (GPER), estrogen receptor α (ERα) and progesterone receptor (PR) immunoreactivity in two hypothalamic regions, the arcuate (ARC) and the periventricular area (PERI) of rhesus monkeys as a model of menopause and hormone replacement. Ovariectomized (OVX) rhesus macaques were young (~11 years) or aged (~25 years), given oil (vehicle) or E2 every 3 weeks for 2 years. Immunohistochemistry and stereologic analysis of ERα, PR, and GPER was performed. More effects were detected for GPER than the other two receptors. Specifically, GPER cell density in the ARC and PERI, and the percent of GPER-immunoreactive cells in the PERI, were greater in aged than in young monkeys. In addition, we mapped the qualitative distribution of GPER in the monkey hypothalamus and nearby regions. For ERα, E2 treated monkeys tended to have higher cell density than vehicle monkeys in the ARC. The percent of PR density in the PERI tended to be higher in E2 than vehicle monkeys of both ages. This study shows that the aged hypothalamus maintains expression of hormone receptors with age, and that long-term cyclic E2 treatment has few effects on their expression, although GPER was affected more than ERα or PR. This result is surprising in light of evidence for E2 regulation of the receptors studied here, and differences may be due to the selected regions, long-term nature of E2 treatment, among other possibilities. PMID:24862737

  3. Evidence for the mechanism of action of the 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated decrease of nuclear estrogen receptor levels in wild-type and mutant mouse Hepa 1c1c7 cells.

    PubMed

    Zacharewski, T; Harris, M; Safe, S

    1991-06-15

    Treatment of wild-type Hepa 1c1c7 cells with 1 nM [3H]-17 beta-estradiol resulted in the rapid accumulation of the nuclear estrogen receptor complex whose levels were maximized within 1 hr. Cotreatment of the cells with 10 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and [3H]-17 beta-estradiol did not affect the nuclear estrogen receptor levels 1 hr after addition of the radioligand; however, pretreatment of the cells for 1, 6, 24 or 42 hr with 10 nM TCDD prior to the addition of the radiolabeled hormone caused a greater than 50% decrease in nuclear estrogen receptor levels (determined by velocity sedimentation analysis) 1 hr after the addition of [3H]-17 beta-estradiol. In parallel experiments in which 10 nM TCDD was added 6 hr prior to the radiolabeled hormone, TCDD caused a 63 and 74% decrease in immunodetectable cytosolic and nuclear estrogen receptor protein levels, respectively, in the wild-type Hepa 1c1c7 cells. The nuclear estrogen receptor was also detected in two Hepa 1c1c7 mutant (class 1 and class 2) cell lines which have been characterized previously as TCDD non-responsive due to either decreased aryl hydrocarbon (Ah) receptor levels or a defect in the accumulation of transcriptionally active nuclear Ah receptor complexes, respectively. Treatment of these mutant cell lines with TCDD and [3H]-17 beta-estradiol (as described above) caused only a minimum (class 1) or non-detectable (class 2) decrease in nuclear estrogen receptor binding activity or immunodetectable protein levels. These results, coupled with the structure-dependent differences in the activities of TCDD (a strong Ah receptor agonist) and 2,8-dichlordibenzo-p-dioxin (a weak Ah receptor agonist) in this assay system, support a role for the Ah receptor in the TCDD-mediated decrease of the nuclear estrogen receptor in mouse Hepa 1c1c7 cells. In addition, actinomycin D and cycloheximide both inhibited the TCDD-mediated decrease of nuclear estrogen receptor levels in the Hepa 1c1c7 wild

  4. Beta adrenergic receptor blockade of feline myocardium. Cardiac mechanics, energetics, and beta adrenoceptor regulation.

    PubMed Central

    Cooper, G; Kent, R L; McGonigle, P; Watanabe, A M

    1986-01-01

    Myocardial oxygen consumption is regulated by interrelated mechanical and inotropic conditions; there is a parallel increase in the aerobic metabolism and inotropic state during beta-adrenergic stimulation under fixed mechanical conditions. In contrast, there is some evidence that beta-blockade may reduce oxygen consumption through effects independent of its influence on mechanical conditions and contractile state, and that prolonged beta-blockade may sensitize the myocardium to beta-adrenergic stimulation. To clarify these two points, the present study examined the relationship of myocardial energetics to mechanics and inotropism during acute beta-blockade and after the withdrawal of long-term beta-blockade, whereupon the basis for any effect observed was sought by characterizing the number, affinity, and affinity states of the beta-receptors as well as the coupling of activated beta-receptors to cyclic AMP generation. Studies of right ventricular papillary muscles from control and chronically beta-blocked cats demonstrated contractile and energetic properties as well as dose-response behavior and inotropic specificity suggestive of an increase in myocardial sensitivity to beta-adrenoceptor stimulation in the latter group. Assays of cardiac beta-adrenoceptors from further groups of control and pretreated cats, both in cardiac tissue and in isolated cardiac muscle cells, failed to define a difference between the two groups either in terms of receptor number and affinity or in terms of the proportion of receptors in the high-affinity state. However, coupling of the activated beta-adrenoceptors to cyclic AMP generation was enhanced in cardiac muscle cells from chronically beta-blocked cats. These data demonstrate that beta-adrenoceptor blockade (a) produces parallel effects on inotropic state and oxygen consumption without an independent effect on either and (b) increases myocardial sensitivity to beta-adrenergic stimulation after beta-blockade withdrawal, not by "up

  5. Regulation of progesterone receptor messenger ribonucleic acid in the rat medial preoptic nucleus by estrogenic and antiestrogenic compounds: an in situ hybridization study.

    PubMed

    Shughrue, P J; Lane, M V; Merchenthaler, I

    1997-12-01

    Progesterone receptor (PR) messenger RNA (mRNA) is concentrated in neurons of the preoptic area and other regions of the rat hypothalamus where it is colocalized with the estrogen receptor and regulated by changes in the steroid hormonal milieu. To date, little is known about the regulation of PR mRNA by estrogens and whether antiestrogenic compounds are capable of modulating its expression. The present studies used in situ hybridization to ascertain the time course of PR mRNA regulation in the medial preoptic nucleus by 17beta-estradiol, determine the effective dose required to elicit a response, and compare the efficacy of 17beta-estradiol with a variety of estrogenic or antiestrogenic compounds. The first series of studies revealed that the treatment of ovariectomized rats with 17beta-estradiol resulted in an increase in PR expression within 2 h, after which it remained elevated until 10 h postinjection and then returned to baseline levels. When ovariectomized rats were injected with 25-1000 ng/kg of 17beta-estradiol and euthanized 6 h later, a dose-dependent increase in the level of PR mRNA was observed, with a maximal response at 1000 ng/kg and an EC50 of 93.5 ng/kg. Subsequent studies evaluated the efficacy of a variety of estrogenic and antiestrogenic compounds in the rat preoptic nucleus. 17Beta-estradiol, diethylstilbestrol, and 17alpha-estradiol all significantly increased the level of PR mRNA, although the degree of induction varied with each compound. The injection of tamoxifen, raloxifene, toremifene, droloxifene, clomiphene, GW 5638, or ICI 182,780 had no significant estrogenic effect on PR gene expression at the dose evaluated. In contrast, when tamoxifen or raloxifene, but not ICI 182,780, was administered in the antagonist mode, a significant dose-related decrease in the estradiol-induced level of PR mRNA was seen in the preoptic area. The results of these studies clearly demonstrate that PR mRNA expression in the rat preoptic area is rapidly

  6. TREATMENT WITH HORMONE THERAPY AND CALCITRIOL DID NOT AFFECT DEPRESSION IN ELDERLY POSTMENOPAUSAL WOMEN: NO INTERACTION WITH ESTROGEN AND VITAMIN D RECEPTOR GENOTYPE POLYMORPHISMS

    PubMed Central

    YALAMANCHILI, VINOD; GALLAGHER, J. CHRISTOPHER

    2011-01-01

    Objective To examine the effect of hormone therapy and calcitriol on depression in elderly postmenopausal women and also to determine whether the response was associated with polymorphisms of estrogen receptor-alpha and vitamin D receptor. Methods In a double-blinded placebo controlled prospective trial involving 489 postmenopausal elderly women, a secondary analysis of depression was done. Geriatric Depression Scale was used to screen for depression. We used binary logistic regression to examine the effect of treatment on depression and one-way ANOVA to find relationship between gene polymorphisms and depression. Results There was no effect of hormone therapy (OR 1.65; 95% CI 0.66–4.12; p = 0.277), calcitriol (OR 1.15; 95% CI 0.43–3.11; p = 0.772) or hormone therapy with calcitriol (OR 1.01; 95% CI 0.36–2.80; p = 0.979) on depression. Neither polymorphisms of estrogen receptor-alpha (XbaI-beta=0.093, CI −0.337–1.350, p = 0.239 and PvuII-beta=−0.064, CI −1.171-0.491, p = 0.421) nor vitamin D receptor (BsmI-beta=0.044, CI −2.546–3.030, p = 0.865 and TaqI-beta=−0.015, CI −2.900-2.738, p = 0.955) were associated with depression. Conclusion In elderly post-menopausal women there was no effect of hormone therapy and calcitriol either individually or in combination with depression. Estrogen receptor-alpha and vitamin D receptor polymorphisms are not associated with depression or the response to intervention in elderly postmenopausal women. Additional trials are required to confirm these findings. PMID:22205149

  7. Bisphenol A regulates the estrogen receptor alpha signaling in developing hippocampus of male rats through estrogen receptor.

    PubMed

    Xu, Xiao-Bin; He, Ye; Song, Chen; Ke, Xin; Fan, Shi-Jun; Peng, Wei-Jie; Tan, Ruei; Kawata, Mitsuhiro; Matsuda, Ken-Ichi; Pan, Bing-Xing; Kato, Nobumasa

    2014-12-01

    Bisphenol A (BPA), one of the most common environmental endocrine disruptors, has been recognized to have wide adverse effects on the brain development and behavior. These adversities are related to its ability to bind estrogen receptor (ER) with subsequent alteration of its expression in the target areas. However, very little is known about whether BPA exposure also affects ER phosphorylation and its translocation to nucleus during postnatal development, two critical steps for its function. Here, we found that during development from postnatal day 7 (P7) to P21, the alpha subtype of ER (ERα) in the hippocampus of male rats experienced remarkable alterations in terms of its expression, phosphorylation and translocation to nucleus. Exposure to low level of BPA had bidirectional, development-dependent effects on the expression of ERα mRNA and protein, but decreased ERα phosphorylation and impaired its translocation to nucleus throughout the period investigated. Treatment with low dose of ICI 182,780 (ICI), an ER antagonist to block the binding of ER with BPA, reversed the altered ERα following BPA exposure, highlighting critical involvement of ER. Moreover, ICI treatment rescued the hippocampus-dependent behavioral deficits in the adult rats experiencing early-life BPA exposure. Overall, our results indicate that BPA interferes with the ERα signaling in the developing hippocampus in an ER-dependent manner, which may underlie its adverse behavioral and cognitive outcomes in adult animals.

  8. Synthesis of Triphenylethylene Bisphenols as Aromatase Inhibitors that Also Modulate Estrogen Receptors

    PubMed Central

    Lv, Wei; Liu, Jinzhong; Skaar, Todd C.; O'Neill, Elizaveta; Yu, Ge; Flockhart, David A.; Cushman, Mark

    2016-01-01

    A series of triphenylethylene bisphenol analogues of the selective estrogen receptor modulator (SERM) tamoxifen were synthesized and evaluated for their abilities to inhibit aromatase, bind to estrogen receptor-α (ER-α) and estrogen receptor-β (ER-β), and antagonize the activity of β-estradiol in MCF-7 human breast cancer cells. The long-range goal has been to create dual aromatase inhibitor (AI)/selective estrogen receptor modulators (SERMs). The hypothesis is that in normal tissue the estrogenic SERM activity of a dual AI/SERM could attenuate the undesired effects stemming from global estrogen depletion caused by the AI activity of a dual AI/SERM, while in breast cancer tissue the antiestrogenic SERM activity of a dual AI/SERM could act synergistically with AI activity to enhance the antiproliferative effect. The potent aromatase inhibitory activities and high ER-α and ER-β binding affinities of several of the resulting analogues, together with the facts that they antagonize β-estradiol in a functional assay in MCF-7 human breast cancer cells and they have no E/Z isomers, support their further development in order to obtain dual AI/SERM agents for breast cancer treatment. PMID:26704594

  9. Molecular cloning and characterization of ligand- and species-specificity of amphibian estrogen receptors.

    PubMed

    Katsu, Yoshinao; Taniguchi, Ena; Urushitani, Hiroshi; Miyagawa, Shinichi; Takase, Minoru; Kubokawa, Kaoru; Tooi, Osamu; Oka, Tomohiro; Santo, Noriaki; Myburgh, Jan; Matsuno, Akira; Iguchi, Taisen

    2010-09-01

    Estrogens are essential for normal reproductive activity in both males and females as well as for ovarian differentiation during a critical developmental stage in most vertebrates. To understand the molecular mechanisms of estrogen action and to evaluate estrogen receptor ligand interactions in amphibians, we isolated cDNAs encoding the estrogen receptors (ERalpha and ERbeta) from the Japanese firebelly newt (Cynops pyrrhogaster), Tokyo salamander (Hynobius tokyoensis), axolotl (Ambystoma mexicanum), and Raucous toad (Bufo rangeri). Full-length amphibian ER cDNAs were obtained using 5' and 3' rapid amplification of cDNA ends. The predicted amino acid sequences of these amphibian ERs showed a high degree of amino acid sequence identity (over 70%) to each other. We analyzed the relationships of these amphibian ER sequences to other vertebrate ER sequences by constructing a phylogenetic tree. We verified that these were bona fide estrogen receptors using receptor dependent reporter gene assays. We analyzed the effects of natural estrogens, ethinylestradiol, and DDT and its metabolites on the transactivation of the four amphibian species listed above, and Xenopus tropicalis ERs and found that there were species-specific differences in the sensitivity of these ERs to hormones and environmental chemicals. These findings will expand our knowledge of endocrine-disrupting events in amphibians.

  10. Metabolism Regulation by Estrogens and Their Receptors in the Central Nervous System Before and After Menopause.

    PubMed

    Coyoy, A; Guerra-Araiza, C; Camacho-Arroyo, I

    2016-08-01

    Estrogens through their intracellular receptors regulate various aspects of glucose and lipid metabolism. The effects of estrogens in metabolism can be mediated by their receptors located in different areas of the brain such as the hypothalamus, which is involved in the control of food intake, energy expenditure, and body weight homeostasis. Alterations in the metabolic regulation by estrogens participate in the pathogenesis of the metabolic syndrome and cardiovascular diseases in women. The metabolic syndrome is an important disease around the world, consisting in a combination of characteristics including abdominal obesity, dyslipidemia, hypertension, and insulin resistance. It increases the risk of cardiovascular disease and type 2 diabetes. It has been suggested that there is an increase in the incidence of metabolic syndrome during menopause due to estrogens deficiency. Estrogens replacement improves insulin sensitivity and reduces the risk of diabetes in rats. In the brain, estrogens through the interaction with their receptors regulate the activity of neurons involved in energy homeostasis, including appetite and satiety. Thus, estradiol and their receptors in the hypothalamus play a key role in metabolic syndrome development during menopause.

  11. Expression and functional roles of G-protein-coupled estrogen receptor (GPER) in human eosinophils.

    PubMed

    Tamaki, Mami; Konno, Yasunori; Kobayashi, Yoshiki; Takeda, Masahide; Itoga, Masamichi; Moritoki, Yuki; Oyamada, Hajime; Kayaba, Hiroyuki; Chihara, Junichi; Ueki, Shigeharu

    2014-07-01

    Sexual dimorphism in asthma links the estrogen and allergic immune responses. The function of estrogen was classically believed to be mediated through its nuclear receptors, i.e., estrogen receptors (ERs). However, recent studies established the important roles of G-protein-coupled estrogen receptor (GPER/GPR30) as a novel membrane receptor for estrogen. To date, the role of GPER in allergic inflammation is poorly understood. The purpose of this study was to examine whether GPER might affect the functions of eosinophils, which play an important role in the pathogenesis of asthma. Here, we demonstrated that GPER was expressed in purified human peripheral blood eosinophils both at the mRNA and protein levels. Although GPER agonist G-1 did not induce eosinophil chemotaxis or chemokinesis, preincubation with G-1 enhanced eotaxin (CCL11)-directed eosinophil chemotaxis. G-1 inhibited eosinophil spontaneous apoptosis and caspase-3 activities. The anti-apoptotic effect was not affected by the cAMP-phospodiesterase inhibitor rolipram or phosphoinositide 3-kinase inhibitors. In contrast to resting eosinophils, G-1 induced apoptosis and increased caspase-3 activities when eosinophils were co-stimulated with IL-5. No effect of G-1 was observed on eosinophil degranulation in terms of release of eosinophil-derived neurotoxin (EDN). The current study indicates the functional capacities of GPER on human eosinophils and also provides the previously unrecognized mechanisms of interaction between estrogen and allergic inflammation.

  12. Estrogen effects on angiotensin receptors are modulated by pituitary in female rats

    SciTech Connect

    Douglas, J.G.

    1987-01-01

    The present studies were designed to test the hypothesis that changes in angiotensin II (ANG II) receptors might modulate the layered target tissue responsiveness accompanying estradiol administration. Estradiol was infused continuously in oophorectomized female rats. Aldosterone was also infused in control and experimental animals to avoid estrogen-induced changes in renin and ANG II. ANG II binding constants were determined in radioreceptor assays. Estradiol increased binding site concentration in adrenal glomerulosa by 76% and decreased binding sites of uterine myometrium and glomeruli by 45 and 24%, respectively. There was an accompanying increase in the affinity of ANG II binding to adrenal glomerulosa and uterine myometrium. Because estrogen is a potent stimulus of prolactin release from the pituitary of rodents, studies were also designed to test the hypothesis that prolactin may mediate some or all of the estrogen-induced effects observed. Hypophysectomy abolished estradiol stimulation of prolactin release and most ANG II receptor changes. Prolactin administration to pituitary intact rats was associated with a 50% increase in receptor density of adrenal glomerulosa simulating estradiol administration. However, the changes in glomeruli and uterine myometrium were opposite in that both tissues also increased receptor density, suggesting that prolactin was not the sole mediator of the estrogen-induced receptor changes. In conclusion, regulation of ANG II receptors in a number of diverse target tissues by estradiol is complex with contributions from estrogens and pituitary factors, which include but do not exclusively involve prolactin.

  13. Estrogen Receptor (ER)-α36 Is Involved in Estrogen- and Tamoxifen-Induced Neuroprotective Effects in Ischemic Stroke Models

    PubMed Central

    Fang, Chen; Ji, Xiaofei; Liang, Xiaofeng; Liu, Yang; Han, Chao; Huang, Liang; Zhang, Qiqi; Li, Hongyan; Zhang, Yejun; Liu, Jinqiu

    2015-01-01

    The neuroprotection by estrogen (E2) and tamoxifen is well documented in experimental stroke models; however, the exact mechanism is unclear. A membrane-based estrogen receptor, ER-α36, has been identified. Postmenopausal-levels of E2 act through ER-α36 to induce osteoclast apoptosis due to a prolonged activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-related kinase (ERK) signaling. We hypothesized that ER-α36 may play a role in the neuroprotective activities of estrogen and tamoxifen. Here, we studied ER-α36 expression in the brain, as well as its neuroprotective effects against oxygen and glucose deprivation (OGD) in PC12 cells. We found that ER-α36 was expressed in both rat and human brain. In addition, OGD-induced cell death was prevented by l nmol/L 17β-estradiol (E2β). E2β activates the MAPK/ERK signaling pathway in PC12 cells under basal and OGD conditions by interacting with ER-α36 and also induces ER-α36 expression. Low-dose of tamoxifen up-regulated ER-α36 expression and enhanced neuronal survival in an ovariectomized ischemic stroke model. Furthermore, low-dose of tamoxifen enhanced neuroprotective effects by modulating activates or suppress ER-α36. Our results thus demonstrated that ER-α36 is involved in neuroprotective activities mediated by both estrogen and tamoxifen. PMID:26484775

  14. Solubilization of the chromatin-bound estrogen receptor from chicken liver and fractionation on hydroxylapatite.

    PubMed

    Gschwendt, M

    1976-08-16

    1. High-affinity estrogen-binding sites can be solubilized from the liver chromatin of estrogenized chickens by treatment of the chromatin with 2 M KCL/5 M urea and fractionation on hydroxylapatite. Two estrogen-binding proteins are eluted from hydroxylapatite columns by 20mM phosphate (binding protein I) and 200mMphosphate (binding protein II), respectively. 2. The binding protein I is part of a non-histone protein fraction containing acid-soluble and insoluble proteins, whereas the binding protein II elutes together with high molecular weight nonhistone proteins containing acid insoluble proteins only. Both binding proteins exhibit the smae affinity for estradiol (Kd approximately 10(-9) M). 3. From chromatin of untreated chickens very small amounts of binding protein I (0.1 pmol/mg protein compared to 1.9 pmol/mg protein from estrogenized chickens) with the smae affinity for estradiol as that from estrogenized animals can be solubilized. Binding protein II is not detectable. 4. The "soluble nuclear estrogen receptor" extracted from crude liver nucleir of estrogenized chickens by 0.5 M KCL behaves on hydroxylapatite very similarly to salt/urea-dissociated chromatin with respect to the binding protein I. No binding protein II, however, can be demonstrated. 5. Chromatography of various preparations on Bio-Gel A-1.5 m indicates that the binding protein II is a residual chromatin fragment containing an unseparated binding protein-DNA complex, whereas the binding protein I represents the solubilized nucleic-acid-free chromosomal estrogen receptor. The "soluble nuclear receptor" and the binding protein I, however, are not identical with respect to their chromatographic behaviour on Bio-Gel A-1.5m, even though their estrogen binding entity remaining after trypsin treatment seems to be very similar.

  15. Estrogen regulates Snail and Slug in the down-regulation of E-cadherin and induces metastatic potential of ovarian cancer cells through estrogen receptor alpha.

    PubMed

    Park, Se-Hyung; Cheung, Lydia W T; Wong, Alice S T; Leung, Peter C K

    2008-09-01

    Tumorigenesis is a multistep process involving dysregulated cell growth and metastasis. Considerable evidence implicates a mitogenic action of estrogen in early ovarian carcinogenesis. In contrast, its influence in the metastatic cascade of ovarian tumor cells remains obscure. In the present study, we showed that 17beta-estradiol (E2) increased the metastatic potential of human epithelial ovarian cancer cell lines. E2 treatment led to clear morphological changes characteristic of epithelial-mesenchymal transition (EMT) and an enhanced cell migratory propensity. These morphological and functional alterations were associated with changes in the abundance of EMT-related genes. Upon E2 stimulation, expression and promoter activity of the epithelial marker E-cadherin were strikingly suppressed, whereas EMT-associated transcription factors, Snail and Slug, were significantly up-regulated. This up-regulation was attributed to the increase in gene transcription activated by E2. Depletion of endogenous Snail or Slug using small interfering RNA (siRNA) attenuated E2-mediated decrease in E-cadherin. In addition, E2-induced cell migration was also neutralized by the siRNAs, suggesting that both transcription factors are indispensable for the prometastatic actions of E2. More importantly, by using selective estrogen receptor (ER) agonists, forced expression, and siRNA approaches, we identified that E2 triggered the metastatic behaviors exclusively through an ERalpha-dependent pathway. We also showed that ERbeta had an opposing action on ERalpha because the presence of ERbeta completely inhibited the EMT and down-regulation of E-cadherin induced by ERalpha. Collectively, this study provides a compelling argument that estrogen can potentiate tumor progression by EMT induction and highlights the crucial role of ERalpha in ovarian tumorigenesis.

  16. Kaempferol inhibits cancer cell growth by antagonizing estrogen-related receptor α and γ activities.

    PubMed

    Wang, Haibin; Gao, Minghui; Wang, Junjian

    2013-11-01

    Kaempferol is a dietary flavonoid that can function as a selective estrogen receptor modulator (SERM). Estrogen-related receptors alpha and gamma (ERRα and ERRγ) are orphan nuclear receptors that play important roles in mitochondrial biogenesis and cancer development. We have shown that kaempferol can functionally antagonize the activities of ERRs based on both response element reporter systems and target gene analysis. Kaempferol modulation of mitochondrial function and suppression cancer cell growth has been confirmed. These findings suggest that kaempferol may exert their anti-cancer activities through antagonizing ERRs activities.

  17. The emerging role of estrogen receptor-β in human reproduction.

    PubMed

    Su, Emily J; Xin, Hong; Monsivais, Diana

    2012-01-01

    Knowledge surrounding estrogen and estrogen receptor biology continues to evolve, and the diversity of their actions and complexity of their mechanisms are becoming increasingly evident. Estrogen receptor (ER) regulation of reproduction is no exception. Although it is well established that estrogen and ERα play key roles in mediating several reproductive biological processes, such as myometrial and endometrial growth, increasing evidence suggests that ERβ is also an important factor. ERβ is a key mediator in folliculogenesis and may also play a role in stimulating ovulation and regulating aspects of luteinization. ERβ is also expressed in higher quantities than ERα in the human myometrium and cervix during pregnancy, and thus it may play a part in the initiation of labor and parturition. Finally, ERβ is the sole ER expressed within the endothelium of the endometrium and the fetoplacental vasculature, and studies suggest that its role may contribute to angiogenic and vasomotor changes that play a role in both implantation and regulation of fetoplacental blood flow.

  18. Identification of G protein-coupled estrogen receptor in human and pig spermatozoa.

    PubMed

    Rago, V; Giordano, F; Brunelli, E; Zito, D; Aquila, S; Carpino, A

    2014-06-01

    Estrogens are known to influence functional properties of mammalian spermatozoa inducing rapid responses through the classical estrogen receptors (ERα and ERβ). Recently, the G protein-coupled estrogen receptor (GPER) has been identified as mediator of fast non-genomic estrogen effects in different cells. This work investigated the expression of GPER in human and pig spermatozoa using immunofluorescence, Western blot analysis and RT-PCR. GPER was found to be confined to the mid-piece of human sperm cells, whereas it was detected in the acrosomal region, the equatorial segment and the mid-piece of pig spermatozoa. Furthermore, in the male gametes of both species, the immunoblots of sperm extracts revealed a band at ~42 kDa, consistent with the GPER molecular weight, and RT-PCR detected the GPER transcripts. This is the first report demonstrating the expression of GPER in human and pig mature sperm cells and evidencing its species-specific cellular localization.

  19. Urethral Dysfunction in Female Mice with Estrogen Receptor β Deficiency

    PubMed Central

    Chen, Yung-Hsiang; Chen, Chao-Jung; Yeh, Shuyuan; Lin, Yu-Ning; Wu, Yang-Chang; Hsieh, Wen-Tsong; Wu, Bor-Tsang; Ma, Wen-Lung; Chen, Wen-Chi; Chang, Chawnshang; Chen, Huey-Yi

    2014-01-01

    Estrogen has various regulatory functions in the growth, development, and differentiation of the female urogenital system. This study investigated the roles of ERβ in stress urinary incontinence (SUI). Wild-type (ERβ+/+) and knockout (ERβ−/−) female mice were generated (aged 6–8 weeks, n = 6) and urethral function and protein expression were measured. Leak point pressures (LPP) and maximum urethral closure pressure (MUCP) were assessed in mice under urethane anesthesia. After the measurements, the urethras were removed for proteomic analysis using label-free quantitative proteomics by nano-liquid chromatography–mass spectrometry (LC-MS/MS) analysis. The interaction between these proteins was further analysed using MetaCore. Lastly, Western blot was used to confirm the candidate proteins. Compared with the ERβ+/+ group, the LPP and MUCP values of the ERβ−/− group were significantly decreased. Additionally, we identified 85 differentially expressed proteins in the urethra of ERβ−/− female mice; 57 proteins were up-regulated and 28 were down-regulated. The majority of the ERβ knockout-modified proteins were involved in cell-matrix adhesion, metabolism, immune response, signal transduction, nuclear receptor translational regelation, and muscle contraction and development. Western blot confirmed the up-regulation of myosin and collagen in urethra. By contrast, elastin was down-regulated in the ERβ−/− mice. This study is the first study to estimate protein expression changes in urethras from ERβ−/− female mice. These changes could be related to the molecular mechanism of ERβ in SUI. PMID:25275480

  20. Estrogen receptor β in Alzheimer's disease: From mechanisms to therapeutics.

    PubMed

    Zhao, Liqin; Woody, Sarah K; Chhibber, Anindit

    2015-11-01

    Alzheimer's disease (AD) disproportionally affects women and men. The female susceptibility for AD has been largely associated with the loss of ovarian sex hormones during menopause. This review examines the current understanding of the role of estrogen receptor β (ERβ) in the regulation of neurological health and its implication in the development and intervention of AD. Since its discovery in 1996, research conducted over the last 15-20 years has documented a great deal of evidence indicating that ERβ plays a pivotal role in a broad spectrum of brain activities from development to aging. ERβ genetic polymorphisms have been associated with cognitive impairment and increased risk for AD predominantly in women. The role of ERβ in the intervention of AD has been demonstrated by the alteration of AD pathology in response to treatment with ERβ-selective modulators in transgenic models that display pronounced plaque and tangle histopathological presentations as well as learning and memory deficits. Future studies that explore the potential interactions between ERβ signaling and the genetic isoforms of human apolipoprotein E (APOE) in brain aging and development of AD-risk phenotype are critically needed. The current trend of lost-in-translation in AD drug development that has primarily been based on early-onset familial AD (FAD) models underscores the urgent need for novel models that recapitulate the etiology of late-onset sporadic AD (SAD), the most common form of AD representing more than 95% of the current human AD population. Combining the use of FAD-related models that generally have excellent face validity with SAD-related models that hold more reliable construct validity would together increase the predictive validity of preclinical findings for successful translation into humans.

  1. Structure, tissue distribution and estrogen regulation of splice variants of the sea bream estrogen receptor α gene.

    PubMed

    Pinto, P I S; Teodósio, R; Socorro, S; Power, D M; Canário, A V M

    2012-07-15

    Estrogen actions are mainly mediated by specific nuclear estrogen receptors (ERs), for which different genes and a diversity of transcript variants have been identified, mainly in mammals. In this study, we investigated the presence of ER splice variants in the teleost fish gilthead sea bream (Sparus auratus), by comparison with the genomic organization of the related species Takifugu rubripes. Two exon2-deleted ERα transcript variants were isolated from liver cDNA of estradiol-treated fish. The ΔE2 variant lacks ERα exon 2, generating a premature termination codon and a putative C-terminal truncated receptor, while the ΔE2,3* variant contains an in-frame deletion of exon 2 and part of exon 3 and codes for a putative ERα protein variant lacking most of the DNA-binding domain. Both variants were expressed at very low levels in several female and male sea bream tissues, and their expression was highly inducible in liver by estradiol-17β treatment with a strong positive correlation with the typical wild-type (wt) ERα response in this tissue. These findings identify novel estrogen responsive splice variants of fish ERα, and provide the basis for future studies to investigate possible modulation of wt-ER actions by splice variants.

  2. Sex and estrogen receptor expression influence opioid peptide levels in the mouse hippocampal mossy fiber pathway.

    PubMed

    Van Kempen, Tracey A; Kahlid, Sana; Gonzalez, Andreina D; Spencer-Segal, Joanna L; Tsuda, Mumeko C; Ogawa, Sonoko; McEwen, Bruce S; Waters, Elizabeth M; Milner, Teresa A

    2013-09-27

    The opioid peptides, dynorphin (DYN) and enkephalin (L-ENK) are contained in the hippocampal mossy fiber pathway where they modulate synaptic plasticity. In rats, the levels of DYN and L-ENK immunoreactivity (-ir) are increased when estrogen levels are elevated (Torres-Reveron et al., 2008, 2009). Here, we used quantitative immunocytochemistry to examine whether opioid levels are similarly regulated in wildtype (WT) mice over the estrous cycle, and how these compared to males. Moreover, using estrogen receptor (ER) alpha and beta knock-out mice (AERKO and BERKO, respectively), the present study examined the role of ERs in rapid, membrane-initiated (6 h), or slower, nucleus-initiated (48 h) estradiol effects on mossy fiber opioid levels. Unlike rats, the levels of DYN and L-ENK-ir did not change over the estrous cycle. However, compared to males, females had higher levels of DYN-ir in CA3a and L-ENK-ir in CA3b. In WT and BERKO ovariectomized (OVX) mice, neither DYN- nor L-ENK-ir changed following 6 or 48 h estradiol benzoate (EB) administration. However, DYN-ir significantly increased 48 h after EB in the dentate gyrus (DG) and CA3b of AERKO mice only. These findings suggest that cyclic hormone levels regulate neither DYN nor L-ENK levels in the mouse mossy fiber pathway as they do in the rat. This may be due to species-specific differences in the mossy fiber pathway. However, in the mouse, DYN levels are regulated by exogenous EB in the absence of ERα possibly via an ERβ-mediated pathway requiring new gene transcription.

  3. Pharmacodynamic imaging guides dosing of a selective estrogen receptor degrader

    PubMed Central

    Heidari, Pedram; Deng, Francis; Esfahani, Shadi A.; Leece, Alicia K.; Shoup, Timothy M.; Vasdev, Neil; Mahmood, Umar

    2015-01-01

    Purpose Estrogen receptor (ER) targeting is key in management of receptor-positive breast cancer (BrCa). Currently, there are no methods to optimize anti-ER therapy dosing. This study assesses the utility of 16α-18F-fluoroestradiol (18F-FES) PET for fulvestrant dose optimization in a preclinical ER+ BrCa model. Experimental Design In vitro, 18F-FES retention was compared to ERα protein expression (ELISA) and ESR1 mRNA transcription (qPCR) in MCF7 cells (ER+) after treatment with different fulvestrant doses. MCF7 xenografts were grown in ovariectomized nude mice and assigned to vehicle, low- (0.05mg), medium- (0.5mg) or high-dose (5mg) fulvestrant treatment groups (5–7 per group). Two and three days after fulvestrant treatment, PET/CT was performed using 18F-FES and 18F-FDG, respectively. ER expression was assessed by immunohistochemistry, ELISA, and qPCR on xenografts. Tumor proliferation was assessed using Ki-67 immunohistochemistry. Results In vitro, we observed a parallel graded reduction in 18F-FES uptake and ER expression with increased fulvestrant doses, despite enhancement of ER mRNA transcription. In xenografts, ER expression significantly decreased with increased fulvestrant dose, despite similar mRNA expression and Ki-67 staining among the treatment groups. We observed a significant dose-dependent reduction of 18F-FES PET mean standardized uptake value (SUVmean) with fulvestrant treatment, but no significant difference among the treatment groups in 18F-FDG PET SUVmean.. Conclusion We demonstrated that 18F-FES uptake mirrors the dose-dependent changes in functional ER expression with fulvestrant resulting in ER degradation and/or blockade; these precede changes in tumor metabolism and proliferation. Quantitative 18F-FES PET may be useful for tracking early efficacy of ER blockade/degradation and guiding ER-targeted therapy dosing in BrCa patients. PMID:25609068

  4. Progesterone receptor modulates estrogen receptor-α action in breast cancer

    PubMed Central

    Mohammed, Hisham; Russell, I. Alasdair; Stark, Rory; Rueda, Oscar M.; Hickey, Theresa E.; Tarulli, Gerard A.; Serandour, Aurelien A. A.; Birrell, Stephen N.; Bruna, Alejandra; Saadi, Amel; Menon, Suraj; Hadfield, James; Pugh, Michelle; Raj, Ganesh V.; Brown, Gordon D.; D’Santos, Clive; Robinson, Jessica L. L.; Silva, Grace; Launchbury, Rosalind; Perou, Charles M.; Stingl, John; Caldas, Carlos; Tilley, Wayne D.; Carroll, Jason S.

    2015-01-01

    Summary Progesterone receptor (PR) expression is employed as a biomarker of estrogen receptor-α (ERα) function and breast cancer prognosis. We now show that PR is not merely an ERα-induced gene target, but is also an ERα-associated protein that modulates its behaviour. In the presence of agonist ligands, PR associates with ERα to direct ERα chromatin binding events within breast cancer cells, resulting in a unique gene expression programme that is associated with good clinical outcome. Progesterone inhibited estrogen-mediated growth of ERα+ cell line xenografts and primary ERα+ breast tumour explants and had increased anti-proliferative effects when coupled with an ERα antagonist. Copy number loss of PgR is a common feature in ERα+ breast cancers, explaining lower PR levels in a subset of cases. Our findings indicate that PR functions as a molecular rheostat to control ERα chromatin binding and transcriptional activity, which has important implications for prognosis and therapeutic interventions. PMID:26153859

  5. Estrogen receptor alpha inhibits senescence-like phenotype and facilitates transformation induced by oncogenic ras in human mammary epithelial cells

    PubMed Central

    Liu, Zhao; Wang, Long; Yang, Junhua; Bandyopadhyay, Abhik; Kaklamani, Virginia; Wang, Shui; Sun, Lu-Zhe

    2016-01-01

    Exposure to estrogen has long been associated with an increased risk of developing breast cancer. However, how estrogen signaling promotes breast carcinogenesis remains elusive. Senescence is known as an important protective response to oncogenic events. We aimed to elucidate the role of estrogen receptor alpha (ERα) on senescence in transformed human mammary epithelial cells and breast cancer cells. Our results show that ectopic expression of oncoprotein H-ras-V12 in immortalized human mammary epithelial cells (HMEC) significantly inhibited the phosphorylation of the retinoblastoma protein (Rb) and increased the activity of the senescence-associated beta-galactosidase (SA-β-Gal). These senescence-like phenotypes were reversed by ectopic expression of ERα. Similar inhibition of the H-ras-V12-induced SA-β-Gal activity by ERα was also observed in the human mammary epithelial MCF-10A cells. Co-expression of ERα and H-ras-V12 resulted in HMEC anchorage-independent growth in vitro and tumor formation in vivo. Furthermore, inhibition of ERα expression induced senescence-like phenotypes in ERα positive human breast cancer cells such as increased activity of SA-β-Gal, decreased phosphorylation of RB, and loss of mitogenic activity. Thus, the suppression of cellular senescence induced by oncogenic signals may be a major mechanism by which ERα promotes breast carcinogenesis. PMID:27259243

  6. Gene expression profiles of estrogen receptor positive and estrogen receptor negative breast cancers are detectable in histologically normal breast epithelium

    PubMed Central

    Graham, Kelly; Ge, Xijin; de las Morenas, Antonio; Tripathi, Anusri; Rosenberg, Carol L.

    2010-01-01

    Purpose Previously, we found that gene expression in histologically normal breast epithelium (NlEpi) from women at high breast cancer risk can resemble gene expression in NlEpi from cancer-containing breasts. Therefore, we hypothesized that gene expression characteristic of a cancer subtype might be seen in NlEpi of breasts containing that subtype. Experimental Design We examined gene expression in 46 cases of microdissected NlEpi from untreated women undergoing breast cancer surgery. From 30 age-matched cases (15 estrogen receptor (ER)+, 15 ER-) we used Affymetryix U133A arrays. From 16 independent cases (9 ER+, 7 ER-), we validated selected genes using qPCR. We then compared gene expression between NlEpi and invasive breast cancer using 4 publicly available datasets. Results We identified 198 genes that are differentially expressed between NlEpi from breasts with ER+ (NlEpiER+) compared to ER- cancers (NlEpiER-). These include genes characteristic of ER+ and ER- cancers (e.g., ESR1, GATA3, and CX3CL1, FABP7). QPCR validated the microarray results in both the 30 original cases and the 16 independent cases. Gene expression in NlEpiER+ and NlEpiER- resembled gene expression in ER+ and ER- cancers, respectively: 25-53% of the genes or probes examined in 4 external datasets overlapped between NlEpi and the corresponding cancer subtype. Conclusions Gene expression differs in NlEpi of breasts containing ER+ compared to ER- breast cancers. These differences echo differences in ER+ and ER- invasive cancers. NlEpi gene expression may help elucidate subtype-specific risk signatures, identify early genomic events in cancer development and locate targets for prevention and therapy. PMID:21059815

  7. Estrogenic actions of norethisterone and its A-ring reduced metabolites. Induction of in vitro uterine sensitivity to serotonin.

    PubMed

    Oropeza, M V; Campos, M G; Lemus, A E; Garciá, G; Pérez-Palacios, G; Ponce-Monter, H

    1994-01-01

    The estrogen-like effects of norethisterone (NET) seem to be mediated by the interaction of 3 beta 5 alpha- and 3 alpha 5 alpha-tetrahydronorethisterone (3 beta 5 alpha- and 3 alpha 5 alpha-NET, respectively) with the estrogen receptor. Considering that the in vitro uterine contractile response to serotonin (5-HT) is specifically dependent on estrogen, the aim of the present study was to investigate whether NET and its A-ring reduced metabolites administered in vivo to ovariectomized rats induce uterine sensitivity to 5-HT in vitro. The administration of 3 beta NET in vivo, which is the NET metabolite with the highest affinity for the estrogen receptor, induced a maximal contractile response to serotonin similar to that of 17 beta-estradiol treatment. The other metabolites induced less uterine activity. According to the effective dose 50, the order of estrogenic potency was 17 beta-estradiol > 3 beta 5 alpha NET > 3 alpha 5 alpha NET > NET > 5 alpha NET. The estrogenic effect of 3 beta 5 alpha- and 3 alpha 5 alpha NET may be exerted through their interaction with the estrogen receptor, whereas NET and 5 alpha NET, which do not bind to the estrogen receptor and display a minor estrogenic activity, require prior bioconversion to 3 beta 5 alpha NET and perhaps to 3 alpha 5 alpha NET. The A-ring reduced metabolites of NET, mainly the 3 beta 5 alpha NET, may be exerting estrogenic responses and modulating uterine activity when administered in vivo.

  8. Structural analysis of beta-adrenergic and muscarinic cholinergic receptors

    SciTech Connect

    Kerlavage, A.R.; Fraser, C.M.; Venter, J.C.

    1987-05-01

    The authors have recently cloned the gene encoding the human brain beta-adrenergic receptor. Beta-adrenergic and muscarinic cholinergic receptors have also been cloned from other tissues. In order to correlate the primary structures of these receptors with their function, they have undertaken detailed mapping of their functionally important sites. Purified guinea pig lung beta receptor was radioiodinated and digested with trypsin. The resultant peptides were resolved by reverse phase HPLC into nine peaks containing /sup 125/I, corresponding exactly with the predicted number of tyrosine containing peptides in the beta receptor. Hamster lung beta receptor was labeled with (/sup 125/I)-iodocyanopindolol diazarine ((/sup 125/I)CYPD) and partially purified by SDS-PAGE. The (/sup 125/I)CYPD-labeled receptor was extracted from the gel, digested with either trypsin or CNBr and the digests were resolved by reverse phase HPLC. The tryptic digest contained one (/sup 125/I)CYPD-labeled peak and the CNBr digest contained two. Rat brain muscarinic receptor was specifically labeled with (/sup 3/H)-propylbenzilyl-choline mustard ((/sup 3/H)PrBCM) and partially purified by SDS-PABE. The (/sup 3/H)PrBCM-labeled receptor was extracted from the gel and digested with CNBr. The resultant HPLC profile revealed a single (/sup 3/H)PrBCM-labeled peak. These data yield information on the location of functional sites within the primary sequences of these receptors.

  9. Estrogen receptor-related receptor alpha mediates up-regulation of aromatase expression by prostaglandin E2 in prostate stromal cells.

    PubMed

    Miao, Lin; Shi, Jiandang; Wang, Chun-Yu; Zhu, Yan; Du, Xiaoling; Jiao, Hongli; Mo, Zengnan; Klocker, Helmut; Lee, Chung; Zhang, Ju

    2010-06-01

    Estrogen receptor-related receptor alpha (ERRalpha) is an orphan member of the nuclear receptor superfamily of transcription factors. ERRalpha is highly expressed in the prostate, especially in prostate stromal cells. However, little is known about the regulation and function of ERRalpha, which may contribute to the progression of prostatic diseases. We previously found that prostaglandin E2 (PGE2) up-regulated the expression of aromatase in prostate stromal cells. Here we show that PGE2 also up-regulates the expression of ERRalpha, which, as a transcription factor, further mediates the regulatory effects of PGE2 on the expression of aromatase. ERRalpha expression was up-regulated by PGE2 in prostate stromal cell line WPMY-1, which was mediated mainly through the protein kinase A signaling pathway by PGE2 receptor EP2. Suppression of ERRalpha activity by chlordane (an antagonist of ERRalpha) or small interfering RNA knockdown of ERRalpha blocked the increase of expression and promoter activity of aromatase induced by PGE2. Overexpression of ERRalpha significantly increased aromatase expression and promoter activity, which were further augmented by PGE2. Chromatin immunoprecipitation assay demonstrated that ERRalpha directly bound to the aromatase promoter in vivo, and PGE2 enhanced the recruitment of ERRalpha and promoted transcriptional regulatory effects on aromatase expression in WPMY-1. 17Beta-estradiol concentration in WPMY-1 medium was up-regulated by ERRalpha expression, and that was further increased by PGE2. Our results provided evidence that ERRalpha contributed to local estrogen production by up-regulating aromatase expression in response to PGE2 and provided further insights into the potential role of ERRalpha in estrogen-related prostatic diseases.

  10. Role of the Neddylation Enzyme Uba3, a New Estrogen Receptor Corepressor, in Breast Cancer

    DTIC Science & Technology

    2005-09-01

    Taylor CW, Akinaga S, Whitesell L 2001 Destabilization of steroid receptors by heat shock protein 90- binding drugs: a ligand- 510 independent approach...or ubiquitin- associated / protein receptor degradation pathways, may thus present an important therapeutic target for future drug intervention. For the... 18 :81-93 13. Fan M, Park A, Nephew KP. Interactions between estrogen receptor and the COOH terminus of the Hsp70-interacting protein (CHIP) (Mol

  11. Androgens act synergistically to enhance estrogen-induced upregulation of human tissue kallikreins 10, 11, and 14 in breast cancer cells via a membrane bound androgen receptor.

    PubMed

    Paliouras, Miltiadis; Diamandis, Eleftherios P

    2008-04-01

    The regulation of gene expression by steroid hormones plays an important role in the normal development and function of many organs, as well as in the pathogenesis of endocrine-related cancers, especially breast cancer. However, clinical data suggest that combined testosterone and estrogen treatments on post-menopausal women increase the risk of breast cancer. Experiments have shown that many, if not all kallikreins are under steroid hormone regulation in breast cancer cell lines. Their implication as prognostic and diagnostic markers has also been well-documented. Thus, we investigated the effect of combined hormone stimulation with androgens and 17beta-estradiol on the ductal caricinoma cell line BT474. This cell line has been shown to be sensitive to both, androgens (secreting PSA) and estrogens (secreting a number of kallikreins including KLK10, 11, and KLK14). We found that PSA expression was downregulated upon combined hormone stimulation, confirming reports that estrogen can antagonize and block the activity of the androgen receptor. Upon analysis of estrogen-sensitive kallikreins 10, 11, and 14, all showed to be synergistically enhanced in their expression three- to fourfold, upon joint hormone treatment versus individual hormone stimulation. The enhancement is dependent upon the action of androgens as treatment with the androgen receptor antagonist cyproterone actetate normalized the expression of KLK10, 11, and KLK14 to estrogen-stimulation levels. The synergistic effects between estrogens and androgens on estrogen-sensitive genes may have implications on the role of the kallikreins in associated risk of breast cancer and progression.

  12. Immunohistochemical analysis of estrogen receptors in prostate and clinical correlation in men with benign prostatic hyperplasia

    PubMed Central

    Gangkak, Goto; Mittal, Alka; Yadav, Sher Singh; Tomar, Vinay; Yadav, Ajay; Mehta, Jayanti

    2017-01-01

    Purpose Estrogens act through interaction with 2 receptor subtypes, ER alpha (ERα) and ER beta (ERβ), in human prostate. The aim of the present study was to semiquantitatively assess the differential expression of ER subtypes in human benign prostatic hyperplasia (BPH) by use of immunocytochemistry (IHC) methods and to explore their relationship with various measures of BPH. Materials and Methods A total of 45 patients with BPH undergoing transurethral resection of the prostate and 22 patients with bladder cancer with normal prostate undergoing surveillance cystoscopy were studied as cases and controls, respectively. Quantitative immunolabeling of ER subtypes was scored by use of a semiquantitative scale. Also, correlations were assessed between ER levels in prostate and various measures of BPH. Results Overall, we found strong immunostaining for ERα in stroma and for ERβ in epithelium, respectively. The IHC score for ERα differed significantly between BPH patients and controls in both stroma (p≤0.001) and epithelium (p=0.008), respectively. The ERβ IHC score was also significantly higher in the epithelium of BPH patients (p=0.01). Also, we found a significant correlation between prostatic ER levels and various clinical measures of BPH. Conclusions ERs may play an important role in the pathogenesis of BPH. PMID:28261681

  13. Two high-affinity ligand binding states of uterine estrogen receptor distinguished by modulation of hydrophobic environment

    SciTech Connect

    Hutchens, T.W.; Li, C.M.; Zamah, N.M.; Besch, P.K.

    1987-02-10

    The steroid binding function of soluble (cytosolic) estrogen receptors from calf uteri was evaluated under conditions known to modify the extent of hydrophobic interaction with receptor-associated proteins. Receptor preparations were equilibrated into 6 M urea buffers and control buffers by chromatography through small columns of Sephadex G-25 or by dialysis at 0.6 /sup 0/C. Equilibrium dissociation constants (K/sub d/) and binding capacities (n) of experimental and control receptor preparations were determined by 13-point Scatchard analyses using concentrations of 17..beta..-(/sup 3/H)estradiol from 0.05 to 10 nM. Nonspecific binding was determined at each concentration by parallel incubations with a 200-fold molar excess of the receptor-specific competitor diethylstilbestrol. The control receptor population was consistently found to be a single class of binding sites with a high affinity for estradiol which was unaffected by G-25 chromatography, by dialysis, by dilution, or by the presence of 0.4 M KCl. However, equilibration into 6 M urea induced a discrete (10-fold) reduction in receptor affinity to reveal a second, thermodynamically stable, high-affinity binding state. The presence of 0.4 M KCl did not significantly influence the discrete change in receptor affinity induced by urea. The effects of urea on both receptor affinity and binding capacity were reversible, suggesting a lack of covalent modification. These results demonstrate nonenzymatic means by which not only the binding capacity but also the affinity of receptor for estradiol can be reversibly controlled, suggesting that high concentrations of urea might be more effectively utilized during the physicochemical characterization and purification of steroid receptor proteins.

  14. The interaction site for tamoxifen aziridine with the bovine estrogen receptor

    SciTech Connect

    Ratajczak, T.; Wilkinson, S.P.; Brockway, M.J.; Haehnel, R.M.; Moritz, R.L.; Begg, G.S.; Simpson, R.J.

    1989-08-15

    Calf uterine estrogen receptor was covalently labeled with ({sup 3}H)tamoxifen aziridine during affinity chromatography purification. After carboxymethylation, affinity labeled receptor was digested with trypsin under limit conditions and the labeled peptides were fractionated by reversed-phase high performance liquid chromatography into one major and two minor components. Sequence analysis of the dominant labeled fragment indicated the facile cleavage of label during Edman degradation but identified two peptides, both derived from the extreme carboxyl terminus of the steroid-binding domain. The 17 residues of one peptide were fully conserved in all estrogen receptors. This fragment contained five nucleophilic amino acids and was considered as the more favored interaction site for tamoxifen aziridine. A corresponding region of the glucocorticoid receptor has recently been identified as one of three major contact sites for glucocorticoids. A comparison of amino acid physical characteristics in the hormone-binding domains of human estrogen and glucocorticoid receptors demonstrated an excellent structural correlation between the two regions and delineated elements in the estrogen receptor which may be directly involved in estradiol binding.

  15. Integrated Summary Report: Validation of Two Binding Assays Using Human Recombinant Estrogen Receptor Alpha (hrERa)

    EPA Science Inventory

    This Integrated Summary Report (ISR) summarizes, in a single document, the results from an international multi-laboratory validation study conducted for two in vitro estrogen receptor (ER) binding assays. These assays both use human recombinant estrogen receptor, alpha subtype (h...

  16. Glyceollin, a novel regulator of mTOR/p70S6 in estrogen receptor positive breast cancer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An estimated 70% of breast cancer tumors utilize estrogen receptor (ER) signaling to maintain tumorigenesis, and targeting of the estrogen receptor is a common method of treatment for these tumor types. However, ER-positive (+) breast cancers often acquire drug resistant or altered ER activity in r...

  17. Estradiol and Estrogen Receptor Agonists Oppose Oncogenic Actions of Leptin in HepG2 Cells

    PubMed Central

    Shen, Minqian; Shi, Haifei

    2016-01-01

    Obesity is a significant risk factor for certain cancers, including hepatocellular carcinoma (HCC). Leptin, a hormone secreted by white adipose tissue, precipitates HCC development. Epidemiology data show that men have a much higher incidence of HCC than women, suggesting that estrogens and its receptors may inhibit HCC development and progression. Whether estrogens antagonize oncogenic action of leptin is uncertain. To investigate potential inhibitory effects of estrogens on leptin-induced HCC development, HCC cell line HepG2 cells were treated with leptin in combination with 17 β-estradiol (E2), estrogen receptor-α (ER-α) selective agonist PPT, ER-β selective agonist DPN, or G protein-coupled ER (GPER) selective agonist G-1. Cell number, proliferation, and apoptosis were determined, and leptin- and estrogen-related intracellular signaling pathways were analyzed. HepG2 cells expressed a low level of ER-β mRNA, and leptin treatment increased ER-β expression. E2 suppressed leptin-induced HepG2 cell proliferation and promoted cell apoptosis in a dose-dependent manner. Additionally E2 reversed leptin-induced STAT3 and leptin-suppressed SOCS3, which was mainly achieved by activation of ER-β. E2 also enhanced ERK via activating ER-α and GPER and activated p38/MAPK via activating ER-β. To conclude, E2 and its receptors antagonize the oncogenic actions of leptin in HepG2 cells by inhibiting cell proliferation and stimulating cell apoptosis, which was associated with reversing leptin-induced changes in SOCS3/STAT3 and increasing p38/MAPK by activating ER-β, and increasing ERK by activating ER-α and GPER. Identifying roles of different estrogen receptors would provide comprehensive understanding of estrogenic mechanisms in HCC development and shed light on potential treatment for HCC patients. PMID:26982332

  18. Binding of amyloid beta peptide to beta2 adrenergic receptor induces PKA-dependent AMPA receptor hyperactivity.

    PubMed

    Wang, Dayong; Govindaiah, G; Liu, Ruijie; De Arcangelis, Vania; Cox, Charles L; Xiang, Yang K

    2010-09-01

    Progressive decrease in neuronal function is an established feature of Alzheimer's disease (AD). Previous studies have shown that amyloid beta (Abeta) peptide induces acute increase in spontaneous synaptic activity accompanied by neurotoxicity, and Abeta induces excitotoxic neuronal death by increasing calcium influx mediated by hyperactive alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors. An in vivo study has revealed subpopulations of hyperactive neurons near Abeta plaques in mutant amyloid precursor protein (APP)-transgenic animal model of Alzheimer's disease (AD) that can be normalized by an AMPA receptor antagonist. In the present study, we aim to determine whether soluble Abeta acutely induces hyperactivity of AMPA receptors by a mechanism involving beta(2) adrenergic receptor (beta(2)AR). We found that the soluble Abeta binds to beta(2)AR, and the extracellular N terminus of beta(2)AR is critical for the binding. The binding is required to induce G-protein/cAMP/protein kinase A (PKA) signaling, which controls PKA-dependent phosphorylation of GluR1 and beta(2)AR, and AMPA receptor-mediated excitatory postsynaptic currents (EPSCs). beta(2)AR and GluR1 also form a complex comprising postsynaptic density protein 95 (PSD95), PKA and its anchor AKAP150, and protein phosphotase 2A (PP2A). Both the third intracellular (i3) loop and C terminus of beta(2)AR are required for the beta(2)AR/AMPA receptor complex. Abeta acutely induces PKA phosphorylation of GluR1 in the complex without affecting the association between two receptors. The present study reveals that non-neurotransmitter Abeta has a binding capacity to beta(2)AR and induces PKA-dependent hyperactivity in AMPA receptors.

  19. Progestin, estrogen and androgen G-protein coupled receptors in fish gonads.

    PubMed

    Thomas, Peter; Dressing, Gwen; Pang, Yefei; Berg, Hakan; Tubbs, Christopher; Benninghoff, Abby; Doughty, Kelly

    2006-04-01

    The identities of the membrane receptors mediating the majority of rapid, cell surface-initiated, nongenomic (i.e. nonclassical) steroid actions described to date are unclear. Two novel 7-transmembrane spanning proteins, representing two distinct classes of steroid membrane receptors, membrane progestin receptor alpha (mPRalpha) and a membrane estrogen receptor (mER), GPR30, have recently been identified in several vertebrate species. Evidence that both receptors activate G-proteins and function as G-protein coupled receptors (GPCRs) is briefly reviewed. New data on progestin actions on fish gametes suggest a widespread involvement of mPRalpha in oocyte maturation and sperm hyperactivity in this vertebrate group. Information on the second messenger pathways activated upon estrogen binding to a membrane estrogen receptor in croaker gonads and preliminary evidence for the presence of a GPR30-like protein in fish gonads are discussed. Finally, initial characterization of the ligand binding, G-protein activation and molecular size of a membrane androgen receptor (mAR) in croaker ovaries suggests the presence of a third unique steroid receptor in fish gonads that also may function as a GPCR.

  20. Fulvestrant radiosensitizes human estrogen receptor-positive breast cancer cells.

    PubMed

    Wang, Jing; Yang, Qifeng; Haffty, Bruce G; Li, Xiaoyan; Moran, Meena S

    2013-02-08

    The optimal sequencing for hormonal therapy and radiation are yet to be determined. We utilized fulvestrant, which is showing promise as an alternative to other agents in the clinical setting of hormonal therapy, to assess the cellular effects of concomitant anti-estrogen therapy (fulvestrant) with radiation (F+RT). This study was conducted to assess the effects of fulvestrant alone vs. F+RT on hormone-receptor positive breast cancer to determine if any positive or negative combined effects exist. The effects of F+RT on human breast cancer cells were assessed using MCF-7 clonogenic and tetrazolium salt colorimetric (MTT) assays. The assays were irradiated with a dose of 0, 2, 4, 6 Gy ± fulvestrant. The effects of F+RT vs. single adjuvant treatment alone on cell-cycle distribution were assessed using flow cytometry; relative expression of repair proteins (Ku70, Ku80, DNA-PKcs, Rad51) was assessed using Western Blot analysis. Cell growth for radiation alone vs. F+RT was 0.885±0.013 vs. 0.622±0.029 @2 Gy, 0.599±0.045 vs. 0.475±0.054 @4 Gy, and 0.472±0.021 vs. 0.380±0.018 @6 Gy RT (p=0.003). While irradiation alone induced G2/M cell cycle arrest, the combination of F+RT induced cell redistribution in the G1 phase and produced a significant decrease in the proportion of cells in G2 phase arrest and in the S phase in breast cancer cells (p<0.01). Furthermore, levels of repair proteins DNA-PKcs and Rad51 were significantly decreased in the cells treated with F+RT compared with irradiation alone. F+RT leads to a decrease in the surviving fraction, increased cell cycle arrest, down regulating of nonhomologous repair protein DNA-PKcs and homologous recombination repair protein RAD51. Thus, our findings suggest that F+RT increases breast cancer cell radiosensitivity compared with radiation alone. These findings have salient implications for designing clinical trials using fulvestrant and radiation therapy.

  1. Fulvestrant radiosensitizes human estrogen receptor-positive breast cancer cells

    SciTech Connect

    Wang, Jing; Yang, Qifeng; Haffty, Bruce G.; Li, Xiaoyan; Moran, Meena S.

    2013-02-08

    Highlights: ► Fulvestrant radiosensitizes MCF-7 cells. ► Fulvestrant increases G1 arrest and decreases S phase in MCF-7 cells. ► Fulvestrant down-regulates DNA-PKcs and RAD51 in MCF-7 cells. -- Abstract: The optimal sequencing for hormonal therapy and radiation are yet to be determined. We utilized fulvestrant, which is showing promise as an alternative to other agents in the clinical setting of hormonal therapy, to assess the cellular effects of concomitant anti-estrogen therapy (fulvestrant) with radiation (F + RT). This study was conducted to assess the effects of fulvestrant alone vs. F + RT on hormone-receptor positive breast cancer to determine if any positive or negative combined effects exist. The effects of F + RT on human breast cancer cells were assessed using MCF-7 clonogenic and tetrazolium salt colorimetric (MTT) assays. The assays were irradiated with a dose of 0, 2, 4, 6 Gy ± fulvestrant. The effects of F + RT vs. single adjuvant treatment alone on cell-cycle distribution were assessed using flow cytometry; relative expression of repair proteins (Ku70, Ku80, DNA-PKcs, Rad51) was assessed using Western Blot analysis. Cell growth for radiation alone vs. F + RT was 0.885 ± 0.013 vs. 0.622 ± 0.029 @2 Gy, 0.599 ± 0.045 vs. 0.475 ± 0.054 @4 Gy, and 0.472 ± 0.021 vs. 0.380 ± 0.018 @6 Gy RT (p = 0.003). While irradiation alone induced G2/M cell cycle arrest, the combination of F + RT induced cell redistribution in the G1 phase and produced a significant decrease in the proportion of cells in G2 phase arrest and in the S phase in breast cancer cells (p < 0.01). Furthermore, levels of repair proteins DNA-PKcs and Rad51 were significantly decreased in the cells treated with F + RT compared with irradiation alone. F + RT leads to a decrease in the surviving fraction, increased cell cycle arrest, down regulating of nonhomologous repair protein DNA-PKcs and homologous recombination repair protein RAD51. Thus, our findings suggest that F + RT

  2. The role of estrogen receptor α in the regulation of bone and growth plate cartilage.

    PubMed

    Börjesson, A E; Lagerquist, M K; Windahl, S H; Ohlsson, C

    2013-11-01

    Estrogens are important endocrine regulators of skeletal growth and maintenance in both females and males. Studies have demonstrated that the estrogen receptor (ER)-α is the main mediator of these estrogenic effects in bone. Therefore, estrogen signaling via ERα is a target both for affecting longitudinal bone growth and bone remodeling. However, treatment with estradiol (E2) leads to an increased risk of side effects such as venous thromboembolism and breast cancer. Thus, an improved understanding of the signaling pathways of ERα will be essential in order to find better bone specific treatments with minimal adverse effects for different estrogen-related bone disorders. This review summarizes the recent data regarding the intracellular signaling mechanisms, in vivo, mediated by the ERα activation functions (AFs), AF-1 and AF-2, and the effect on bone, growth plate and other estrogen responsive tissues. In addition, we review the recent cell-specific ERα-deleted mouse models lacking ERα specifically in neuronal cells or growth plate cartilage. The newly characterized signaling pathways of estrogen, described in this review, provide a better understanding of the ERα signaling pathways, which may facilitate the design of new, bone-specific treatment strategies with minimal adverse effects.

  3. Tumor suppressor ING4 inhibits estrogen receptor activity in breast cancer cells

    PubMed Central

    Keenen, Madeline M; Kim, Suwon

    2016-01-01

    Resistance to antiestrogen therapy remains a significant problem in breast cancer. Low expression of inhibitor of growth 4 (ING4) in primary tumors has been correlated with increased rates of recurrence in estrogen receptor-positive (ER+) breast cancer patients, suggesting a role for ING4 in ER signaling. This study provides evidence that ING4 inhibits ER activity. ING4 overexpression increased the sensitivity of T47D and MCF7 ER+ breast cancer cells to hormone deprivation. ING4 attenuated maximal estrogen-dependent cell growth without affecting the dose–response of estrogen. These results indicated that ING4 functions as a noncompetitive inhibitor of estrogen signaling and may inhibit estrogen-independent ER activity. Supportive of this, treatment with fulvestrant but not tamoxifen rendered T47D cells sensitive to hormone deprivation as did ING4 overexpression. ING4 did not affect nuclear ERα protein expression, but repressed selective ER-target gene transcription. Taken together, these results demonstrated that ING4 inhibited estrogen-independent ER activity, suggesting that ING4-low breast tumors recur faster due to estrogen-independent ER activity that renders tamoxifen less effective. This study puts forth fulvestrant as a proposed therapy choice for patients with ING4-low ER+ breast tumors. PMID:27895513

  4. Functional analysis of retinoid Z receptor beta, a brain-specific nuclear orphan receptor.

    PubMed Central

    Greiner, E F; Kirfel, J; Greschik, H; Dörflinger, U; Becker, P; Mercep, A; Schüle, R

    1996-01-01

    The retinoid Z receptor beta (RZR beta), an orphan receptor, is a member of the retinoic acid receptor (RAR)/thyroid hormone receptor (TR) subfamily of nuclear receptors. RZR beta exhibits a highly restricted brain-specific expression pattern. So far, no natural RZR beta target gene has been identified and the physiological role of the receptor in transcriptional regulation remains to be elucidated. Electrophoretic mobility shift assays reveal binding of RZR beta to monomeric response elements containing the sequence AnnTAGGTCA, but RZR beta-mediated transactivation of reporter genes is only achieved with two property spaced binding sites. We present evidence that RZR beta can function as a cell-type-specific transactivator. In neuronal cells, GaI-RZR beta fusion proteins function as potent transcriptional activators, whereas no transactivation can be observed in nonneuronal cells. Mutational analyses demonstrate that the activation domain (AF-2) of RZR beta and RAR alpha are functionally interchangeable. However, in contrast to RAR and TR, the RZR beta AF-2 cannot function autonomously as a transactivation domain. Furthermore, our data define a novel repressor function for the C-terminal part of the putative ligand binding domain. We propose that the transcriptional activity of RZR beta is regulated by an interplay of different receptor domains with coactivators and corepressors. Images Fig. 5 PMID:8816759

  5. 17β-Estradiol Inhibits Wound Healing in Male Mice via Estrogen Receptor

    PubMed Central

    Gilliver, Stephen C.; Emmerson, Elaine; Campbell, Laura; Chambon, Pierre; Hardman, Matthew J.; Ashcroft, Gillian S.

    2010-01-01

    Although estrogens have long been known to accelerate healing in females, their roles in males remain to be established. To address this, we have investigated the influence of 17β-estradiol on acute wound repair in castrated male mice. We report that sustained exposure to estrogen markedly delays wound re-epithelialization. Our use of hairless mice revealed this response to be largely independent of hair follicle cycling, whereas other studies demonstrated that estrogen minimally influences wound inflammation in males. Additionally, we report reduced collagen accumulation and increased gelatinase activities in the wounds of estrogen-treated mice. Increased wound matrix metalloproteinase (MMP)-2 activity in these animals may i) contribute to their inability to heal skin wounds optimally and ii) stem, at least in part, from effects on the overall levels and spatial distribution of membrane-type 1-MMP and tissue inhibitor of MMP (TIMP)-3, which respectively facilitate and prevent MMP-2 activation. Using mice rendered null for either the α or β isoform of the estrogen receptor, we identified estrogen receptor-α as the likely effector of estrogen’s inhibitory effects on healing. PMID:20448060

  6. Serum estrogen receptor bioactivity and breast cancer risk among postmenopausal women.

    PubMed

    Lim, Vanessa W; Li, Jun; Gong, Yinhan; Jin, Aizhen; Yuan, Jian-Min; Yong, Eu Leong; Koh, Woon-Puay

    2014-04-01

    The estrogen levels of Asian women are different from those of Western women, and this could affect estrogen receptor (ER) bioactivity and breast cancer risk. We conducted a case-control study in 169 postmenopausal breast cancer cases and 426 matched controls nested within a population-based prospective cohort study, the Singapore Chinese Health Study, to evaluate the serum levels of estrogens and their receptor (ERα and ERβ)-mediated estrogenic activities in relation to breast cancer risk. Breast cancer cases had higher levels of estrogens and ER-mediated bioactivities in baseline serum than the controls. Compared with those in the lowest quartile, women in the highest quartile for estrone (E1) or ERα-mediated bioactivity had increased breast cancer risk. After additional adjustment for ERβ bioactivity, free estradiol, and E1 levels, serum ERα-mediated bioactivity remained associated with increased breast cancer risk. Compared with those in the lowest quartile, women in the highest quartile for ERα-mediated bioactivity had an odds ratio of 2.39 (95% CI=1.17-4.88; P for trend=0.016). Conversely, the positive association between E1 and cancer risk became null after adjustment for ERα-mediated bioactivity, suggesting that the effect of E1 could be mediated through ERα. Factor(s) contributing to increased ERα-mediated estrogenic bioactivity in serum and its role as a predictor for breast cancer risk need to be validated in future studies.

  7. Non-nuclear-initiated actions of the estrogen receptor protect cortical bone mass.

    PubMed

    Bartell, Shoshana M; Han, Li; Kim, Ha-neui; Kim, Sung Hoon; Katzenellenbogen, John A; Katzenellenbogen, Benita S; Chambliss, Ken L; Shaul, Philip W; Roberson, Paula K; Weinstein, Robert S; Jilka, Robert L; Almeida, Maria; Manolagas, Stavros C

    2013-04-01

    Extensive evidence has suggested that at least some of the effects of estrogens on bone are mediated via extranuclear estrogen receptor α signaling. However, definitive proof for this contention and the extent to which such effects may contribute to the overall protective effects of estrogens on bone maintenance have remained elusive. Here, we investigated the ability of a 17β-estradiol (E2) dendrimer conjugate (EDC), incapable of stimulating nuclear-initiated actions of estrogen receptor α, to prevent the effects of ovariectomy (OVX) on the murine skeleton. We report that EDC was as potent as an equimolar dose of E2 in preventing bone loss in the cortical compartment that represents 80% of the entire skeleton, but was ineffective on cancellous bone. In contrast, E2 was effective in both compartments. Consistent with its effect on cortical bone mass, EDC partially prevented the loss of both vertebral and femoral strength. In addition, EDC, as did E2, prevented the OVX-induced increase in osteoclastogenesis, osteoblastogenesis, and oxidative stress. Nonetheless, the OVX-induced decrease in uterine weight was unaltered by EDC but was restored by E2. These results demonstrate that the protection of cortical bone mass by estrogens is mediated, at least in part, via a mechanism that is distinct from the classic mechanism of estrogen action on reproductive organs.

  8. The Expanding Complexity of Estrogen Receptor Signaling in the Cardiovascular System.

    PubMed

    Menazza, Sara; Murphy, Elizabeth

    2016-03-18

    Estrogen has important effects on cardiovascular function including regulation of vascular function, blood pressure, endothelial relaxation, and the development of hypertrophy and cardioprotection. However, the mechanisms by which estrogen mediates these effects are still poorly understood. As detailed in this review, estrogen can regulate transcription by binding to 2 nuclear receptors, ERα and ERβ, which differentially regulate gene transcription. ERα and ERβ regulation of gene transcription is further modulated by tissue-specific coactivators and corepressors. Estrogen can bind to ERα and ERβ localized at the plasma membrane as well as G-protein-coupled estrogen receptor to initiate membrane delimited signaling, which enhances kinase signaling pathways that can have acute and long-term effects. The kinase signaling pathways can also mediate transcriptional changes and can synergize with the ER to regulate cell function. This review will summarize the beneficial effects of estrogen in protecting the cardiovascular system through ER-dependent mechanisms with an emphasis on the role of the recently described ER membrane signaling mechanisms.

  9. Cooperative binding of estrogen receptor to imperfect estrogen-responsive DNA elements correlates with their synergistic hormone-dependent enhancer activity.

    PubMed

    Martinez, E; Wahli, W

    1989-12-01

    The Xenopus vitellogenin (vit) gene B1 estrogen-inducible enhancer is formed by two closely adjacent 13 bp imperfect palindromic estrogen-responsive elements (EREs), i.e. ERE-2 and ERE-1, having one and two base substitutions respectively, when compared to the perfect palindromic consensus ERE (GGTCANNNTGACC). Gene transfer experiments indicate that these degenerated elements, on their own, have a low or no regulatory capacity at all, but in vivo act together synergistically to confer high receptor- and hormone-dependent transcription activation to the heterologous HSV thymidine kinase promoter. Thus, the DNA region upstream of the vitB1 gene comprising these two imperfect EREs separated by 7 bp, was called the vitB1 estrogen-responsive unit (vitB1 ERU). Using in vitro protein-DNA interaction techniques, we demonstrate that estrogen receptor dimers bind cooperatively to the imperfect EREs of the vitB1 ERU. Binding of a first receptor dimer to the more conserved ERE-2 increases approximately 4- to 8-fold the binding affinity of the receptor to the adjacent less conserved ERE-1. Thus, we suggest that the observed synergistic estrogen-dependent transcription activation conferred by the pair of hormone-responsive DNA elements of the vit B1 ERU is the result of cooperative binding of two estrogen receptor dimers to these two adjacent imperfect EREs.

  10. Regulation of Mitochondrial Respiratory Chain Biogenesis by Estrogens/Estrogen Receptors and Physiological, Pathological and Pharmacological Implications

    PubMed Central

    Chen, Jin-Qiang; Cammarata, Patrick R.; Baines, Christopher P.; Yager, James D.

    2009-01-01

    There has been increasing evidence pointing to the mitochondrial respiratory chain (MRC) as a novel and important target for the actions of 17β-estradiol(E2) and estrogen receptors (ER) in a number of cell types and tissues that have high demands for mitochondrial energy metabolism. This novel E2-mediated mitochondrial pathway involves the cooperation of both nuclear and mitochondrial ERα and ERβ and their co-activators on the coordinate regulation of both nuclear DNA- and mitochondrial DNA-encoded genes for MRC proteins. In this paper, we have: 1) comprehensively reviewed studies that reveal a novel role of estrogens and ERs in the regulation of MRC biogenesis; 2) discussed their physiological, pathological and pharmacological implications in the control of cell proliferation and apoptosis in relation to estrogen-mediated carcinogenesis, anticancer drug resistance in human breast cancer cells, neuro-protection for Alzheimer’s disease and Parkinson’s disease in brain, cardiovascular protection in human heart and their beneficial effects in lens physiology related to cataract in the eye; and 3) pointed out new research directions to address the key questions in this important and newly emerging area. We also suggest a novel conceptual approach that will contribute to innovative regimines for the prevention or treatment of a wide variety of medical complications based on E2/ER-mediated MRC biogenesis pathway. PMID:19559056

  11. Leptin receptor expression during the progression of endometrial carcinoma is correlated with estrogen and progesterone receptors

    PubMed Central

    Méndez-López, Luis Fernando; Zavala-Pompa, Angel; Cortés-Gutiérrez, Elva I.; Cerda-Flores, Ricardo M.

    2016-01-01

    Introduction The hormone leptin, which is produced in the adipose tissue, may influence tumorigenesis directly via its receptor (Ob-R). Thus, a role for Ob-R in endometrial carcinogenesis has been proposed. However, most studies neither included samples of the entire histological progression of endometrial carcinoma nor examined Ob-R jointly with the estrogen and progesterone receptors (ER and PR, respectively). Material and methods To determine the fluctuations of Ob-R, ER, and PR during the histological progression of endometrial carcinoma, we assessed their expression via immunohistochemistry (IHC) in six histological types of endometrium (proliferative, secretory, nonatypical and atypical hyperplasia, and endometrioid and nonendometrioid endometrial carcinoma), in which we performed histopathological and digital scoring for the quantification of receptors. Results We found that Ob-R expression was positively correlated with that of ER and PR (r = 1, p < 0.001; r = 0.943, p < 0.005, respectively), and there was a significant difference in Ob-R expression among proliferative normal endometrium, hyperplasias, and carcinomas, according to their relative digitally scored Ob-R expression (p < 0.001). In addition, we observed that Ob-R expression in the secretory endometrium was more similar to that of carcinomas than to its proliferative counterpart. Conclusions These results indicate that Ob-R expression fluctuates during endometrial carcinogenesis in correlation with ER and PR, suggesting that Ob-R expression in vivo is highly dependent on estrogen and progesterone activities in the endometrium and on its ER and PR status, as suggested previously by in vitro studies. PMID:28144276

  12. Food-associated estrogenic compounds induce estrogen receptor-mediated luciferase gene expression in transgenic male mice.

    PubMed

    Ter Veld, Marcel G R; Zawadzka, E; van den Berg, J H J; van der Saag, Paul T; Rietjens, Ivonne M C M; Murk, Albertinka J

    2008-07-30

    The present paper aims at clarifying to what extent seven food-associated compounds, shown before to be estrogenic in vitro, can induce estrogenic effects in male mice with an estrogen receptor (ER)-mediated luciferase (luc) reporter gene system. The luc induction was determined in different tissues 8h after dosing the ER-luc male mice intraperitoneally (IP) or 14h after oral dosing. Estradiol-propionate (EP) was used as a positive control at 0.3 and 1mg/kg bodyweight (bw), DMSO as solvent control. The food-associated estrogenic compounds tested at non-toxic doses were bisphenol A (BPA) and nonylphenol (NP) (both at 10 and 50mg/kgbw), dichlorodiphenyldichloroethylene (p,p'-DDE; at 5 and 25mg/kgbw), quercetin (at 1.66 and 16.6mg/kgbw), di-isoheptyl phthalate (DIHP), di-(2-ethylhexyl) phthalate (DEHP) and di-(2-ethylhexyl) adipate (DEHA) all at 30 and 100mg/kgbw. In general IP dosing resulted in higher luc inductions than oral dosing. EP induced luc activity in the liver in a statistically significant dose-related way with the highest induction of all compounds tested which was 20,000 times higher than the induction by the DMSO-control. NP, DDE, DEHA and DIHP did not induce luc activity in any of the tissues tested. BPA induced luc in the liver up to 420 times via both exposure routes. BPA, DEHP and quercetin induced luc activity in the liver after oral exposure. BPA (50mg/kgbw IP) also induced luc activity in the testis, kidneys and tibia. The current study reveals that biomarker-responses in ER-luc male mice occur after a single oral exposure to food-associated estrogenic model compounds at exposure levels 10 to 10(4) times higher than the established TDI's for some of these compounds. Given the facts that (i) the present study did not include chronic exposure and that (ii) simultaneous exposure to multiple estrogenic compounds may be a realistic exposure scenario, it remains to be seen whether this margin is sufficiently high.

  13. Selective Estrogen Receptor Modulators Suppress Hif1α Protein Accumulation in Mouse Osteoclasts

    PubMed Central

    Iwasaki, Ryotaro; Kobayashi, Tami; Watanabe, Ryuichi; Oike, Takatsugu; Toyama, Yoshiaki; Matsumoto, Morio; Nakamura, Masaya; Kawana, Hiromasa; Nakagawa, Taneaki; Miyamoto, Takeshi

    2016-01-01

    Anti-bone resorptive drugs such as bisphosphonates, the anti-RANKL antibody (denosumab), or selective estrogen receptor modulators (SERMs) have been developed to treat osteoporosis. Mechanisms underlying activity of bisphosphonates or denosumab in this context are understood, while it is less clear how SERMs like tamoxifen, raloxifene, or bazedoxifene inhibit bone resorption. Recently, accumulation of hypoxia inducible factor 1 alpha (Hif1α) in osteoclasts was shown to be suppressed by estrogen in normal cells. In addition, osteoclast activation and decreased bone mass seen in estrogen-deficient conditions was found to require Hif1α. Here, we used western blot analysis of cultured osteoclast precursor cells to show that tamoxifen, raloxifene, or bazedoxifene all suppress Hif1α protein accumulation. The effects of each SERM on osteoclast differentiation differed in vitro. Our results suggest that interventions such as the SERMs evaluated here could be useful to inhibit Hif1α and osteoclast activity under estrogen-deficient conditions. PMID:27802325

  14. Memo interacts with c-Src to control Estrogen Receptor alpha sub-cellular localization.

    PubMed

    Frei, Anna; MacDonald, Gwen; Lund, Ingrid; Gustafsson, Jan-Åke; Hynes, Nancy E; Nalvarte, Ivan

    2016-08-30

    Understanding the complex interaction between growth factor and steroid hormone signaling pathways in breast cancer is key to identifying suitable therapeutic strategies to avoid progression and therapy resistance. The interaction between these two pathways is of paramount importance for the development of endocrine resistance. Nevertheless, the molecular mechanisms behind their crosstalk are still largely obscure. We previously reported that Memo is a small redox-active protein that controls heregulin-mediated migration of breast cancer cells. Here we report that Memo sits at the intersection between heregulin and estrogen signaling, and that Memo controls Estrogen Receptor alpha (ERα) sub-cellular localization, phosphorylation, and function downstream of heregulin and estrogen in breast cancer cells. Memo facilitates ERα and c-Src interaction, ERα Y537 phosphorylation, and has the ability to control ERα extra-nuclear localization. Thus, we identify Memo as an important key mediator between the heregulin and estrogen signaling pathways, which affects both breast cancer cell migration and proliferation.

  15. Estrogen receptor-β in mitochondria: implications for mitochondrial bioenergetics and tumorigenesis.

    PubMed

    Liao, Tien-Ling; Tzeng, Chii-Ruey; Yu, Chao-Lan; Wang, Yi-Pei; Kao, Shu-Huei

    2015-09-01

    Estrogen enhances mitochondrial function by enhancing mitochondrial biogenesis and sustaining mitochondrial energy-transducing capacity. Shifts in mitochondrial bioenergetic pathways from oxidative phosphorylation to glycolysis have been hypothesized to be involved in estrogen-induced tumorigenesis. Studies have shown that mitochondria are an important target of estrogen. Estrogen receptor-β (ERβ) has been shown to localize to mitochondria in a ligand-dependent or -independent manner and can affect mitochondrial bioenergetics and anti-apoptotic signaling. However, the functional role of mitochondrial ERβ in tumorigenesis remains unclear. Clinical studies of ERβ-related tumorigenesis have shown that ERβ stimulates mitochondrial metabolism to meet the high energy demands of processes such as cell proliferation, cell survival, and transformation. Thus, in elucidating the precise role of mitochondrial ERβ in cell transformation and tumorigenesis, it will be particularly valuable to explore new approaches for the development of medical treatments targeting mitochondrial ERβ-mediated mitochondrial function and preventing apoptosis.

  16. Estrogen receptor-α is localized to neurofibrillary tangles in Alzheimer’s disease

    PubMed Central

    Wang, Chunyu; Zhang, Fan; Jiang, Sirui; Siedlak, Sandra L.; Shen, Lu; Perry, George; Wang, Xinglong; Tang, Beisha; Zhu, Xiongwei

    2016-01-01

    The female predominance for developing Alzheimer disease (AD) suggests the involvement of gender specific factor(s) such as a reduced estrogen-estrogen receptor signaling in the pathogenesis of AD. The potential role of ERα in AD pathogenesis has been explored by several groups with mixed results. We revisited this issue of expression and distribution of ERα in AD brain using a specific ERα antibody. Interestingly, we found that ERα co-localized with neurofibrillary pathology in AD brain and further demonstrated that ERα interacts with tau protein in vivo. Immunoprecipitaion experiments found increased ERα-tau interaction in the AD cases, which may account for ERα being sequestered in neuronal tau pathology. Indeed, tau overexpression in M17 cells leads to interruption of estrogen signaling. Our data support the idea that sequestration of ERα by tau pathology underlies the loss of estrogen neuroprotection during the course of AD. PMID:26837465

  17. Determination of the Role of Estrogen Receptors and Estrogen Regulated Genes in B Cell Autoreactivity

    DTIC Science & Technology

    2011-07-01

    Medical Research Manhasset, NY 11030 Systemic lupus erythematosus is an autoimmune disease that occurs preferentially in women. We have developed a...Introduction: There is abundant clinical data that estrogen can increase risk of developing systemic lupus erythematosus (SLE) and disease...crux of systemic lupus erythematosus (SLE). SLE is characterized by an array of antibodies against self-antigens (3,4). Anti–double-stranded (ds) DNA

  18. Determination of the Role of Estrogen Receptors and Estrogen Regulated Genes in B Cell Autoreactivity

    DTIC Science & Technology

    2010-07-01

    14. ABSTRACT Systemic lupus erythematosus (SLE) is an autoimmune disease that occurs preferentially in women. In murine models of SLE, it is... Systemic Lupus , Estrogen, BCR Signaling, B Cell Maturation, B Cell Selection 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF...therefore, be important to test ERα antagonists in murine studies of B cell development and in murine models of lupus . This approach to therapy might

  19. Determination of the Role of Estrogen Receptors and Estrogen Regulated Genes in B cell Autoreactivity. Addendum

    DTIC Science & Technology

    2012-07-01

    14. ABSTRACT Systemic lupus erythematosus is an autoimmune disease that occurs preferentially in women. We have developed a murine model...4 Introduction: There is abundant clinical data that estrogen can increase risk of developing systemic lupus erythematosus (SLE) and disease...Kawabata, D., Pinto-Rodriguez, D., Grimaldi, C. and Diamond B. Hormonal regulator of B cell function and systemic lupus erythematosus . Lupus 17:528

  20. Treatment of beta amyloid 1–42 (Aβ1–42)-induced basal forebrain cholinergic damage by a non-classical estrogen signaling activator in vivo

    PubMed Central

    Kwakowsky, Andrea; Potapov, Kyoko; Kim, SooHyun; Peppercorn, Katie; Tate, Warren P.; Ábrahám, István M.

    2016-01-01

    In Alzheimer’s disease (AD), there is a loss in cholinergic innervation targets of basal forebrain which has been implicated in substantial cognitive decline. Amyloid beta peptide (Aβ1–42) accumulates in AD that is highly toxic for basal forebrain cholinergic (BFC) neurons. Although the gonadal steroid estradiol is neuroprotective, the administration is associated with risk of off-target effects. Previous findings suggested that non-classical estradiol action on intracellular signaling pathways has ameliorative potential without estrogenic side effects. After Aβ1–42 injection into mouse basal forebrain, a single dose of 4-estren-3α, 17β-diol (estren), the non-classical estradiol pathway activator, restored loss of cholinergic cortical projections and also attenuated the Aβ1–42-induced learning deficits. Estren rapidly and directly phosphorylates c-AMP-response–element-binding-protein and extracellular-signal-regulated-kinase-1/2 in BFC neurons and restores the cholinergic fibers via estrogen receptor-α. These findings indicated that selective activation of non-classical intracellular estrogen signaling has a potential to treat the damage of cholinergic neurons in AD. PMID:26879842

  1. Estrogen-like activity of perfluoroalkyl acids in vivo and interaction with human and rainbow trout estrogen receptors in vitro.

    PubMed

    Benninghoff, Abby D; Bisson, William H; Koch, Daniel C; Ehresman, David J; Kolluri, Siva K; Williams, David E

    2011-03-01

    The objectives of this study were to determine the structural characteristics of perfluoroalkyl acids (PFAAs) that confer estrogen-like activity in vivo using juvenile rainbow trout (Oncorhynchus mykiss) as an animal model and to determine whether these chemicals interact directly with the estrogen receptor (ER) using in vitro and in silico species comparison approaches. Perfluorooctanoic (PFOA), perfluorononanoic (PFNA), perfluorodecanoic (PFDA), and perfluoroundecanoic (PFUnDA) acids were all potent inducers of the estrogen-responsive biomarker protein vitellogenin (Vtg) in vivo, although at fairly high dietary exposures. A structure-activity relationship for PFAAs was observed, where eight to ten fluorinated carbons and a carboxylic acid end group were optimal for maximal Vtg induction. These in vivo findings were corroborated by in vitro mechanistic assays for trout and human ER. All PFAAs tested weakly bound to trout liver ER with half maximal inhibitory concentration (IC(50)) values of 15.2-289 μM. Additionally, PFOA, PFNA, PFDA, PFUnDA, and perlfuorooctane sulfonate (PFOS) significantly enhanced human ERα-dependent transcriptional activation at concentrations ranging from 10-1000 nM. Finally, we employed an in silico computational model based upon the crystal structure for the human ERα ligand-binding domain complexed with E2 to structurally investigate binding of these putative ligands to human, mouse, and trout ERα. PFOA, PFNA, PFDA, and PFOS all efficiently docked with ERα from different species and formed a hydrogen bond at residue Arg394/398/407 (human/mouse/trout) in a manner similar to the environmental estrogens bisphenol A and nonylphenol. Overall, these data support the contention that several PFAAs are weak environmental xenoestrogens of potential concern.

  2. Estrogen-Like Activity of Perfluoroalkyl Acids In Vivo and Interaction with Human and Rainbow Trout Estrogen Receptors In Vitro

    PubMed Central

    Benninghoff, Abby D.; Bisson, William H.; Koch, Daniel C.; Ehresman, David J.; Kolluri, Siva K.; Williams, David E.

    2011-01-01

    The objectives of this study were to determine the structural characteristics of perfluoroalkyl acids (PFAAs) that confer estrogen-like activity in vivo using juvenile rainbow trout (Oncorhynchus mykiss) as an animal model and to determine whether these chemicals interact directly with the estrogen receptor (ER) using in vitro and in silico species comparison approaches. Perfluorooctanoic (PFOA), perfluorononanoic (PFNA), perfluorodecanoic (PFDA), and perfluoroundecanoic (PFUnDA) acids were all potent inducers of the estrogen-responsive biomarker protein vitellogenin (Vtg) in vivo, although at fairly high dietary exposures. A structure-activity relationship for PFAAs was observed, where eight to ten fluorinated carbons and a carboxylic acid end group were optimal for maximal Vtg induction. These in vivo findings were corroborated by in vitro mechanistic assays for trout and human ER. All PFAAs tested weakly bound to trout liver ER with half maximal inhibitory concentration (IC50) values of 15.2–289μM. Additionally, PFOA, PFNA, PFDA, PFUnDA, and perlfuorooctane sulfonate (PFOS) significantly enhanced human ERα-dependent transcriptional activation at concentrations ranging from 10–1000nM. Finally, we employed an in silico computational model based upon the crystal structure for the human ERα ligand-binding domain complexed with E2 to structurally investigate binding of these putative ligands to human, mouse, and trout ERα. PFOA, PFNA, PFDA, and PFOS all efficiently docked with ERα from different species and formed a hydrogen bond at residue Arg394/398/407 (human/mouse/trout) in a manner similar to the environmental estrogens bisphenol A and nonylphenol. Overall, these data support the contention that several PFAAs are weak environmental xenoestrogens of potential concern. PMID:21163906

  3. Selective Estrogen Receptor Modulators: Cannabinoid Receptor Inverse Agonists with Differential CB1 and CB2 Selectivity

    PubMed Central

    Franks, Lirit N.; Ford, Benjamin M.; Prather, Paul L.

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are used to treat estrogen receptor (ER)-positive breast cancer and osteoporosis. Interestingly, tamoxifen and newer classes of SERMs also exhibit cytotoxic effects in cancers devoid of ERs, indicating a non-estrogenic mechanism of action. Indicative of a potential ER-independent target, reports demonstrate that tamoxifen binds to cannabinoid receptors (CBRs) with affinity in the low μM range and acts as an inverse agonist. To identify cannabinoids with improved pharmacological properties relative to tamoxifen, and further investigate the use of different SERM scaffolds for future cannabinoid drug development, this study characterized the affinity and activity of SERMs in newer structural classes at CBRs. Fourteen SERMs from five structurally distinct classes were screened for binding to human CBRs. Compounds from four of five SERM classes examined bound to CBRs. Subsequent studies fully characterized CBR affinity and activity of one compound from each class. Ospemifine (a triphenylethylene) selectively bound to CB1Rs, while bazedoxifine (an indole) bound to CB2Rs with highest affinity. Nafoxidine (a tetrahydronaphthalene) and raloxifene (RAL; a benzothiaphene) bound to CB1 and CB2Rs non-selectively. All four compounds acted as inverse agonists at CB1 and CB2Rs, reducing basal G-protein activity with IC50 values in the nM to low μM range. Ospemifine, bazedoxifene and RAL also acted as inverse agonists to elevate basal intracellular cAMP levels in intact CHO-hCB2 cells. The four SERMs examined also acted as CB1 and CB2R antagonists in the cAMP assay, producing rightward shifts in the concentration-effect curve of the CBR agonist CP-55,940. In conclusion, newer classes of SERMs exhibit improved pharmacological characteristics (e.g., in CBR affinity and selectivity) relative to initial studies with tamoxifen, and thus suggest that different SERM scaffolds may be useful for development of safe and selective drugs acting

  4. From empirical to mechanism-based discovery of clinically useful Selective Estrogen Receptor Modulators (SERMs)

    PubMed Central

    Wardell, Suzanne E.; Nelson, Erik R.; McDonnell, Donald P.

    2014-01-01

    Our understanding of the molecular mechanisms underlying the pharmacological actions of estrogen receptor (ER) ligands has evolved considerably in recent years. Much of this knowledge has come from a detailed dissection of the mechanism(s) of action of the Selective Estrogen Receptor Modulators (SERMs) tamoxifen and raloxifene, drugs whose estrogen receptor (ER) agonist/antagonist properties are influenced by the cell context in which they operate. These studies have revealed that notwithstanding differences in drug pharmokinetics, the activity of an ER ligand is determined primarily by (a) the impact that a given ligand has on the receptor conformation and (b) the ability of structurally distinct ER-ligand complexes to interact with functionally distinct coregulators. Exploitation of the established relationships between ER structure and activity has led to the development of improved SERMs with more favorable therapeutic properties and of tissue-selective estrogen complexes, drugs in which a SERM and an ER agonist are combined to yield a blended activity that results in distinct clinical profiles. Remarkably, endogenous ligands that exhibit SERM activity have also been identified. One of these ligands, 27-hydroxycholesterol (27HC), has been shown to manifest ER-dependent pathological activities in the cardiovascular system, bone and mammary gland. Whereas the physiological activity of 27HC remains to be determined, its discovery highlights how cells have adopted mechanisms to allow the same receptor ligand complex to manifest different activities in different cells, and also how these processes can be exploited for new drug development. PMID:25084324

  5. A demonstration of the uncertainty in predicting the estrogenic activity of individual chemicals and mixtures from an in vitro estrogen receptor transcriptional activation assay (T47D-KBluc) to the in vivo uterotrophic assay using oral exposure

    EPA Science Inventory

    In vitro estrogen receptor assays are valuable screening tools for identifying environmental samples and chemicals that display estrogenic activity. However, in vitro potency cannot necessarily be extrapolated to estimates of in vivo potency because in vitro assays are currently...

  6. Estrogen Stimulation of Kiss1 Expression in the Medial Amygdala Involves Estrogen Receptor-α But Not Estrogen Receptor-β.

    PubMed

    Stephens, Shannon B Z; Chahal, Navdeep; Munaganuru, Nagambika; Parra, Ruby A; Kauffman, Alexander S

    2016-10-01

    The neuropeptide kisspeptin, encoded by Kiss1, regulates reproduction by stimulating GnRH secretion. Neurons synthesizing kisspeptin are predominantly located in the hypothalamic anteroventral periventricular (AVPV) and arcuate nuclei, but smaller kisspeptin neuronal populations also reside in extrahypothalamic brain regions, such as the medial amygdala (MeA). In adult rodents, estradiol (E2) increases Kiss1 expression in the MeA, as in the AVPV. However, unlike AVPV and arcuate nuclei kisspeptin neurons, little else is currently known about the development, regulation, and function of MeA Kiss1 neurons. We first assessed the developmental onset of MeA Kiss1 expression in males and found that MeA Kiss1 expression is absent at juvenile ages but significantly increases during the late pubertal period, around postnatal day 35, coincident with increases in circulating sex steroids. We next tested whether developmental MeA Kiss1 expression could be induced early by E2 exposure prior to puberty. We found that juvenile mice given short-term E2 had greatly increased MeA Kiss1 expression at postnatal day 18. Although MeA Kiss1 neurons are known to be E2 up-regulated, the specific estrogen receptor (ER) pathway(s) mediating this stimulation are unknown. Using adult ERα knockout and ERβ knockout mice, we next determined that ERα, but not ERβ, is required for maximal E2-induced MeA Kiss1 expression in both sexes. These results delineate both the developmental time course of MeA Kiss1 expression and the specific ER signaling pathway required for E2-induced up-regulation of Kiss1 in this extrahypothalamic brain region. These findings will help drive future studies ascertaining the potential functions of this understudied kisspeptin population.

  7. Mas receptor is involved in the estrogen-receptor induced nitric oxide-dependent vasorelaxation.

    PubMed

    Sobrino, Agua; Vallejo, Susana; Novella, Susana; Lázaro-Franco, Macarena; Mompeón, Ana; Bueno-Betí, Carlos; Walther, Thomas; Sánchez-Ferrer, Carlos; Peiró, Concepción; Hermenegildo, Carlos

    2017-04-01

    The Mas receptor is involved in the angiotensin (Ang)-(1-7) vasodilatory actions by increasing nitric oxide production (NO). We have previously demonstrated an increased production of Ang-(1-7) in human umbilical vein endothelial cells (HUVEC) exposed to estradiol (E2), suggesting a potential cross-talk between E2 and the Ang-(1-7)/Mas receptor axis. Here, we explored whether the vasoactive response and NO-related signalling exerted by E2 are influenced by Mas. HUVEC were exposed to 10nM E2 for 24h in the presence or absence of the selective Mas receptor antagonist A779, and the estrogen receptor (ER) antagonist ICI182780 (ICI). E2 increased Akt and endothelial nitric oxide synthase (eNOS) mRNA and protein expression, measured by RT-PCR and Western blot, respectively. Furthermore, E2 increased Akt activity (determined by the levels of phospho-Ser(473)) and eNOS activity (by the enhanced phosphorylation of Ser(1177), the activated form), resulting in increased NO production, which was measured by the fluorescence probe DAF-2-FM. These signalling events were dependent on ER and Mas receptor activation, since they were abolished in the presence of ICI or A779. In ex-vivo functional experiments performed with a small-vessel myograph in isolated mesenteric vessels from wild-type mice pre-contracted with noradrenaline, the relaxant response to physiological concentrations of E2 was blocked by ICI and A779, to the same extent to that obtained in the vessels isolated from Mas-deficient. In conclusion, E2 induces NO production and vasodilation through mechanisms that require Mas receptor activation.

  8. Gemini vitamin D analogues inhibit estrogen receptor-positive and estrogen receptor-negative mammary tumorigenesis without hypercalcemic toxicity.

    PubMed

    Lee, Hong Jin; Paul, Shiby; Atalla, Nadi; Thomas, Paul E; Lin, Xinjie; Yang, Ill; Buckley, Brian; Lu, Gang; Zheng, Xi; Lou, You-Rong; Conney, Allan H; Maehr, Hubert; Adorini, Luciano; Uskokovic, Milan; Suh, Nanjoo

    2008-11-01

    Numerous preclinical, epidemiologic, and clinical studies have suggested the benefits of vitamin D and its analogues for the prevention and treatment of cancer. However, the hypercalcemic effects have limited the use of 1alpha,25(OH)(2)D(3), the hormonally active form of vitamin D. To identify vitamin D analogues with better efficacy and low toxicity, we have tested >60 novel Gemini vitamin D analogues with a unique structure of two side chains for growth inhibition of breast cancer cells. Our initial studies found that some Gemini analogues are 5-15 times more active than 1alpha,25(OH)(2)D(3) in growth inhibition assay. In vivo experiments were designed to study the inhibitory effect of selected Gemini vitamin D analogues against mammary carcinogenesis by using (a) an N-methyl-N-nitrosourea-induced estrogen receptor (ER)-positive mammary tumor model and (b) an MCF10DCIS.com xenograft model of ER-negative mammary tumors. Among vitamin D analogues we tested, Gemini 0072 [1alpha,25-dihydroxy-20S-21(3-trideuteromethyl-3-hydroxy-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-19-nor-cholecalciferol] and Gemini 0097 [1alpha,25-dihydroxy-20R-21(3-trideuteromethyl-3-hydroxy-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-19-nor-cholecalciferol] administration inhibited by 60% the NMU-induced mammary tumor burden compared with the NMU-treated control group, but these compounds were devoid of hypercalcemia toxicity. In an ER-negative xenograft model, Gemini 0097 significantly suppressed tumor growth without hypercalcemia toxicity. We found that the inhibitory effect of Gemini 0097 was associated with an increased level of cyclin-dependent kinase inhibitor p21 and the insulin-like growth factor binding protein 3 in both ER-positive and ER-negative mammary tumors. Our results suggest that Gemini vitamin D analogues may be potent agents for the prevention and treatment of both ER-positive and ER-negative breast cancer without hypercalcemia toxicity.

  9. The deletion of the estrogen receptor α gene reduces susceptibility to estrogen-induced cholesterol cholelithiasis in female mice

    PubMed Central

    de Bari, Ornella; Wang, Helen H.; Portincasa, Piero; Liu, Min; Wang, David Q.-H.

    2015-01-01

    Compelling evidence has demonstrated that estrogen is a critical risk factor for gallstone formation and enhances cholesterol cholelithogenesis through the hepatic estrogen receptor α (ERα), but not ERβ. To study the lithogenic mechanisms of estrogen through ERα, we investigated whether the deletion of Erα protects against gallstone formation in ovariectomized (OVX) female mice fed a lithogenic diet and treated with 17β-estradiol (E2) at 0 or 6 μg/day for 56 days. Our results showed that the prevalence of gallstones was reduced from 100% in OVX ERα (+/+) mice to 30% in OVX ERα (−/−) mice in response to high doses of E2 and the lithogenic diet for 56 days. Hepatic cholesterol secretion was significantly diminished in OVX ERα (−/−) mice compared to OVX ERα (+/+) mice even fed the lithogenic diet and treated with E2 for 56 days. These alterations decreased bile lithogenicity by reducing cholesterol saturation index of gallbladder bile. Immunohistochemical studies revealed that ERα was expressed mainly in the gallbladder smooth muscle cells. High levels of E2 impaired gallbladder emptying function mostly through the ERα and cholecystokinin-1 receptor pathway, leading to gallbladder stasis in OVX ERα (+/+) mice. By contrast, gallbladder emptying function was greatly improved in OVX ERα (−/−) mice. This markedly retarded cholesterol crystallization and the growth and agglomeration of solid cholesterol crystals into microlithiasis and stones. In conclusion, the deletion of Erα reduces susceptibility to the formation of E2-induced gallstones by diminishing hepatic cholesterol secretion, desaturating gallbladder bile, and improving gallbladder contraction function in female mice. PMID:26232687

  10. Histone Demethylase JMJD2B Functions as a Co-Factor of Estrogen Receptor in Breast Cancer Proliferation and Mammary Gland Development

    PubMed Central

    Kawazu, Masahito; McQuire, Tracy; Goto, Kouichiro; Son, Dong-Ok; Wakeham, Andrew; Miyagishi, Makoto; Mak, Tak W.; Okada, Hitoshi

    2011-01-01

    Estrogen is a key regulator of normal function of female reproductive system and plays a pivotal role in the development and progression of breast cancer. Here, we demonstrate that JMJD2B (also known as KDM4B) constitutes a key component of the estrogen signaling pathway. JMJD2B is expressed in a high proportion of human breast tumors, and that expression levels significantly correlate with estrogen receptor (ER) positivity. In addition, 17-beta-estradiol (E2) induces JMJD2B expression in an ERα dependent manner. JMJD2B interacts with ERα and components of the SWI/SNF-B chromatin remodeling complex. JMJD2B is recruited to ERα target sites, demethylates H3K9me3 and facilitates transcription of ER responsive genes including MYB, MYC and CCND1. As a consequence, knockdown of JMJD2B severely impairs estrogen-induced cell proliferation and the tumor formation capacity of breast cancer cells. Furthermore, Jmjd2b-deletion in mammary epithelial cells exhibits delayed mammary gland development in female mice. Taken together, these findings suggest an essential role for JMJD2B in the estrogen signaling, and identify JMJD2B as a potential therapeutic target in breast cancer. PMID:21445275

  11. CITED2 modulates estrogen receptor transcriptional activity in breast cancer cells

    SciTech Connect

    Lau, Wen Min; Doucet, Michele; Huang, David; Weber, Kristy L.; Kominsky, Scott L.

    2013-07-26

    Highlights: •The effects of elevated CITED2 on ER function in breast cancer cells are examined. •CITED2 enhances cell growth in the absence of estrogen and presence of tamoxifen. •CITED2 functions as a transcriptional co-activator of ER in breast cancer cells. -- Abstract: Cbp/p300-interacting transactivator with Glu/Asp-rich carboxy-terminal domain 2 (CITED2) is a member of the CITED family of non-DNA binding transcriptional co-activators of the p300/CBP-mediated transcription complex. Previously, we identified CITED2 as being overexpressed in human breast tumors relative to normal mammary epithelium. Upon further investigation within the estrogen receptor (ER)-positive subset of these breast tumor samples, we found that CITED2 mRNA expression was elevated in those associated with poor survival. In light of this observation, we investigated the effect of elevated CITED2 levels on ER function. While ectopic overexpression of CITED2 in three ER-positive breast cancer cell lines (MCF-7, T47D, and CAMA-1) did not alter cell proliferation in complete media, growth was markedly enhanced in the absence of exogenous estrogen. Correspondingly, cells overexpressing CITED2 demonstrated reduced sensitivity to the growth inhibitory effects of the selective estrogen receptor modulator, 4-hydroxytamoxifen. Subsequent studies revealed that basal ER transcriptional activity was elevated in CITED2-overexpressing cells and was further increased upon the addition of estrogen. Similarly, basal and estrogen-induced expression of the ER-regulated genes trefoil factor 1 (TFF1) and progesterone receptor (PGR) was higher in cells overexpressing CITED2. Concordant with this observation, ChIP analysis revealed higher basal levels of CITED2 localized to the TFF-1 and PGR promoters in cells with ectopic overexpression of CITED2, and these levels were elevated further in response to estrogen stimulation. Taken together, these data indicate that CITED2 functions as a transcriptional co

  12. Neuroprotective effect of estrogen: role of nonsynaptic NR2B-containing NMDA receptors.

    PubMed

    Liu, Shui-bing; Zhao, Ming-gao

    2013-04-01

    Excessive activation of N-methyl-D-aspartate receptors (NMDARs) has been implicated in the pathophysiology of chronic neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and Huntington's disease. Some studies reported that NR2A and NR2B play different roles in the central nervous system (CNS). The NR2A subunit is primarily found in the synapses and is required for glutamate-mediated neuronal survival. On the other hand, the NR2B subunit is primarily found in the extrasynaptic sites and is required for glutamate-mediated neuronal death in both in vitro and in vivo experiments. Estrogen is a steroid hormone well known for its widespread effects such as neuroprotection in the brain. Classically, estrogen can bind to two kinds of nuclear receptors, namely, estrogen receptor α (ERα) and estrogen receptor β (ERβ), and produce physiological and neuroprotective effects. Aside from nuclear receptors, estrogen has one membrane receptor, which can either be G-protein-coupled receptor 30 (GPR30), Gq-mER, or ER-X. NMDA exposure clearly promotes NR2B subunit phosphorylation at Ser-1303 and causes neuronal cell death. GPR30 mediates rapid non-genomic effects to protect neurons against injury by inhibiting p-DAPK1 dephosphorylation, which inhibits NR2B subunit phosphorylation at Ser-1303. In addition, NMDA exposure and global ischemia activate the autophagy pathway and induce cell death, which are markedly blocked by the NR2B antagonist Ro 25-6981. Thus, NR2B signaling, autophagy induction and cell death may be closely related. Ro 25-6981 inhibits the dissociation of the NR2B-Beclin-1 signaling complex and delays autophagy in vivo, thus confirming the link between NR2B signaling and autophagy. In short, ERα, ERβ, and GPR30 are involved in the neuroprotection of estrogen in the CNS. Additional research must be conducted to reveal the mechanism of estrogen action fully and to identify better targets for the development of more effective drugs. This

  13. Truncating Prolactin Receptor Mutations Promote Tumor Growth in Murine Estrogen Receptor-Alpha Mammary Carcinomas.

    PubMed

    Griffith, Obi L; Chan, Szeman Ruby; Griffith, Malachi; Krysiak, Kilannin; Skidmore, Zachary L; Hundal, Jasreet; Allen, Julie A; Arthur, Cora D; Runci, Daniele; Bugatti, Mattia; Miceli, Alexander P; Schmidt, Heather; Trani, Lee; Kanchi, Krishna-Latha; Miller, Christopher A; Larson, David E; Fulton, Robert S; Vermi, William; Wilson, Richard K; Schreiber, Robert D; Mardis, Elaine R

    2016-09-27

    Estrogen receptor alpha-positive (ERα+) luminal tumors are the most frequent subtype of breast cancer. Stat1(-/-) mice develop mammary tumors that closely recapitulate the biological characteristics of this cancer subtype. To identify transforming events that contribute to tumorigenesis, we performed whole genome sequencing of Stat1(-/-) primary mammary tumors and matched normal tissues. This investigation identified somatic truncating mutations affecting the prolactin receptor (PRLR) in all tumor and no normal samples. Targeted sequencing confirmed the presence of these mutations in precancerous lesions, indicating that this is an early event in tumorigenesis. Functional evaluation of these heterozygous mutations in Stat1(-/-) mouse embryonic fibroblasts showed that co-expression of truncated and wild-type PRLR led to aberrant STAT3 and STAT5 activation downstream of the receptor, cellular transformation in vitro, and tumor formation in vivo. In conclusion, truncating mutations of PRLR promote tumor growth in a model of human ERα+ breast cancer and warrant further investigation.

  14. International Union of Basic and Clinical Pharmacology. XCVII. G Protein–Coupled Estrogen Receptor and Its Pharmacologic Modulators

    PubMed Central

    2015-01-01

    Estrogens are critical mediators of multiple and diverse physiologic effects throughout the body in both sexes, including the reproductive, cardiovascular, endocrine, nervous, and immune systems. As such, alterations in estrogen function play important roles in many diseases and pathophysiological conditions (including cancer), exemplified by the lower prevalence of many diseases in premenopausal women. Estrogens mediate their effects through multiple cellular receptors, including the nuclear receptor family (ERα and ERβ) and the G protein–coupled receptor (GPCR) family (GPR30/G protein–coupled estrogen receptor [GPER]). Although both receptor families can initiate rapid cell signaling and transcriptional regulation, the nuclear receptors are traditionally associated with regulating gene expression, whereas GPCRs are recognized as mediating rapid cellular signaling. Estrogen-activated pathways are not only the target of multiple therapeutic agents (e.g., tamoxifen, fulvestrant, raloxifene, and aromatase inhibitors) but are also affected by a plethora of phyto- and xeno-estrogens (e.g., genistein, coumestrol, bisphenol A, dichlorodiphenyltrichloroethane). Because of the existence of multiple estrogen receptors with overlapping ligand specificities, expression patterns, and signaling pathways, the roles of the individual receptors with respect to the diverse array of endogenous and exogenous ligands have been challenging to ascertain. The identification of GPER-selective ligands however has led to a much greater understanding of the roles of this receptor in normal physiology and disease as well as its interactions with the classic estrogen receptors ERα and ERβ and their signaling pathways. In this review, we describe the history and characterization of GPER over the past 15 years focusing on the pharmacology of steroidal and nonsteroidal compounds that have been employed to unravel the biology of this most recently recognized estrogen receptor. PMID

  15. Androgen and estrogen receptors are present in primary cultures of human synovial macrophages.

    PubMed

    Cutolo, M; Accardo, S; Villaggio, B; Barone, A; Sulli, A; Coviello, D A; Carabbio, C; Felli, L; Miceli, D; Farruggio, R; Carruba, G; Castagnetta, L

    1996-02-01

    Macrophages, as antigen-processing and -presenting cells to T lymphocytes, play a key role in the immune system and are suspected to be target cells of the sex hormone-related dimorphism in the immune response peculiar to rheumatoid arthritis (RA) pathology. In the present study, the use of specific monoclonal antibodies revealed immunostaining for androgen and estrogen receptors in primary cultures of macrophages obtained from synovial tissues of patients affected by RA and controls without RA disease. Soluble and nuclear type I (high affinity, low capacity) and type II (lower affinity, greater capacity) sites of androgen or estrogen binding were detected in primary cultures of RA macrophages using radioligand binding assay. Higher levels of type I and type II estrogen receptor compared to those of androgen receptor were found, particularly in the soluble fraction; however, contrary to what was observed in whole synovial tissues, higher steroid receptor concentrations were found in the soluble than in the nuclear fraction of RA synovial macrophages. Binding affinities and receptor contents of cultured synovial macrophages were comparable to those previously reported in other well established sex hormone-responsive cells and tissues. Further, specific messenger ribonucleic acids for sex hormone receptors, encoding for a sequence of the DNA-binding domain of the receptor proteins were revealed by RT-PCR.

  16. Effects of genistein and estrogen receptor subtype-specific agonists in ArKO mice following different administration routes.

    PubMed

    Bliedtner, Anja; Zierau, Oliver; Albrecht, Steffen; Liebhaber, Steffi; Vollmer, Günter

    2010-01-15

    We have scrutinized the effects of the phytoestrogen genistein and three synthetic estrogen receptor agonists, 17 alpha-ethynylestradiol (EE), propylpyrazole-triol (PPT) and diarylpropionitrile (DPN) in the completely estrogen-free background of aromatase knockout (ArKO) mice by means of two routes of substance administration: oral via diet (per os; po) or subcutaneous injection (sc) with the intention to evaluate the ArKO mice as sensitive model organism for uterotrophic assays. Additionally, we were aiming to qualitatively analyze effects resulting from oral administration path, in particular for PPT and DPN. Therefore, we analyzed the resulting uterine wet weights (UWW) and epithelial heights as physiological endpoints of function as well as the gonadotropin levels. Moreover, the gene expression profiles of estrogen receptors as well as important uterine and ovarian estrogen-response genes were investigated by real-time PCR. The uterus of ArKO mice responded very sensitive upon the substitution with EE (sc 5 microg/kg BW; po 50 microg/kg BW) in a proliferative manner. This was evaluated inter alia by increased UWW and by up-regulation of the expression of proliferation-associated and estrogen-response genes. It is important to note, that ER alpha and ER beta-agonist, PPT and DPN respectively (po 5mg/kg BW and sc 0.5mg/kg BW), have only been used for sc applications so far. Here, effects resulting from oral application were qualitatively described and evaluated for their applicability. The UWW and expression of proliferation-associated genes were increased following both po and sc treatment with PPT. In contrast, DPN did not exert an increase of the UWW, but a significant decrease of proliferation-associated gene and protein expression. Additionally, a substantial hypoplasia was detectable in the uterine cross-sections of DPN-treated mice. On the other hand, the phytoestrogen genistein (sc 10mg/kg BW; po 70 mg/kg BW) did not cause detectable uterotrophic

  17. Serum estrogen and tumor-positive estrogen receptor-alpha are strong prognostic classifiers of non-small-cell lung cancer survival in both men and women.

    PubMed

    Olivo-Marston, Susan E; Mechanic, Leah E; Mollerup, Steen; Bowman, Elise D; Remaley, Alan T; Forman, Michele R; Skaug, Vidar; Zheng, Yun-Ling; Haugen, Aage; Harris, Curtis C

    2010-10-01

    The role of tumor estrogen receptors (ERs) and serum estrogen in lung cancer is inconclusive. We investigated the hypothesis that ERs and functional single-nucleotide polymorphisms in the estrogen biosynthesis pathway are associated with poorer lung cancer survival. Lung cancer patients (n = 305) from a National Cancer Institute-Maryland (NCI-MD) case-case cohort in the Baltimore metropolitan area were used as a test cohort. To validate, 227 cases from the NCI-MD case-control cohort and 293 cases from a Norwegian lung cancer cohort were studied. Information on demographics, tobacco and reproductive histories was collected in an interviewer-administered questionnaire. Serum estrogen, progesterone, tumor messenger RNA expression of hormone receptors and germ line DNA polymorphisms were analyzed for associations with lung cancer survival. Patients in the highest tertile of serum estrogen had worse survival in all three cohorts (P combined < 0.001). Furthermore, the variant allele of estrogen receptor alpha (ER-α) polymorphism (rs2228480) was significantly associated with increased tumor ER-α levels and worse survival in all three cohorts [hazard ratio (HR) = 2.59, 95% confidence interval (CI): 1.20- 4.01; HR = 1.76, 95% CI: 1.08-2.87 and HR = 2.85, 95% CI: 1.31-4.36). Other polymorphisms associated with lower serum estrogen correlated with improved survival. Results were independent of gender and hormone replacement therapy. We report a significant association of increased serum estrogen with poorer survival among lung cancer male and female patients. Understanding the genetic control of estrogen biosynthesis and response in lung cancer could lead to improved prognosis and therapy.

  18. CLONING, EXPRESSION AND CHARACTERIZATION OF THE ANDROGEN RECEPTOR AND ISOLATION OF ESTROGEN RECEPTOR ALPHA FROM THE FATHEAD MINNOW (PIMEPHALES PROMELAS)

    EPA Science Inventory

    In vitro screening assays designed to identify hormone mimics or antagonists, including those recommended for use in the EPA's Tier 1 screening battery, typically use mammalian estrogen (ER) and androgen receptors (AR) such as rat or human. Although we know that the amino acid s...

  19. Identification and characterization of estrogen receptor-related receptor alpha and gamma in human glioma and astrocytoma cells.

    PubMed

    Gandhari, Mukesh K; Frazier, Chester R; Hartenstein, Julia S; Cloix, Jean-Francois; Bernier, Michel; Wainer, Irving W

    2010-02-05

    The purpose of this study was to examine expression and function of estrogen receptor-related receptors (ERRs) in human glioma and astrocytoma cell lines. These estrogen receptor-negative cell lines expressed ERRalpha and ERRgamma proteins to varying degree in a cell context dependent manner, with U87MG glioma cells expressing both orphan nuclear receptors. Cell proliferation assays were performed in the presence of ERR isoform-specific agonists and antagonists, and the calculated EC(50) and IC(50) values were consistent with previous reported values determined in other types of cancer cell lines. Induction of luciferase expression under the control of ERR isoform-specific promoters was also observed in these cells. These results indicate that ERRalpha and ERRgamma are differentially expressed in these tumor cell lines and likely contribute to agonist-dependent ERR transcriptional activity.

  20. Species comparisons in molecular and functional attributes of the androgen and estrogen receptor

    EPA Science Inventory

    While endocrine disrupting compounds (EDCs) have the potential to act via several mechanisms of action, one of the most widely studied is the ability of environmental chemicals to interact directly with either the estrogen (ER) or androgen receptor (AR). In vitro screening assay...

  1. Nature of the binding interaction for 50 structurally diverse chemicals with rat estrogen receptors

    EPA Science Inventory

    This study was conducted to characterize the estrogen receptor (ER)-binding affinities of 50 chemicals selected from among the high production volume chemicals under the U.S. EPA's (U.S. Environmental Protection Agency's) Toxic Substances Control Act inventory. The chemicals were...

  2. COMPARATIVE DOCKING STUDIES OF THE BINDING OF POLYCYCLIC AROMATIC HYDROCARBONS TO THE ESTROGEN RECEPTOR

    EPA Science Inventory

    The interactions of several PAHs, and some of their possible metabolites, with the ligand binding domain of the estrogen receptor have been examined using molecular docking and quantum mechanical methods. The geometries of the PAHs were optimized at the Hartree-Fock level and the...

  3. Tetrahydroisoquinoline Phenols: Selective Estrogen Receptor Downregulator Antagonists with Oral Bioavailability in Rat

    PubMed Central

    2015-01-01

    A series of tetrahydroisoquinoline phenols was modified to give an estrogen receptor downregulator-antagonist profile. Optimization around the core, alkyl side chain, and pendant aryl ring resulted in compounds with subnanomolar levels of potency. The phenol functionality was shown to be required to achieve highly potent compounds, but unusually this was compatible with obtaining high oral bioavailabilities in rat. PMID:26819673

  4. A subpopulation of estrogen receptors are modified by O-linked N-acetylglucosamine.

    PubMed

    Jiang, M S; Hart, G W

    1997-01-24

    Estrogen receptors (ER) are ligand-inducible transcription factors regulated by Ser(Thr)-O-phosphorylation. Many transcription factors and eukaryotic RNA polymerase II itself are also dynamically modified by Ser(Thr)-O-linked N-acetylglucosamine moieties (O-GlcNAc). Here we report that subpopulations of murine, bovine, and human estrogen receptors are modified by O-GlcNAc. O-GlcNAc moieties were detected on insect cell-expressed, mouse ER (mER) by probing with bovine milk galactosyltransferase, followed by stru