Fibroblasts maintained in 3 dimensions show a better differentiation state and higher sensitivity to estrogens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montani, Claudia; Steimberg, Nathalie; Boniotti, Jennifer

2014-11-01

Cell differentiation and response to hormonal signals were studied in a 3D environment on an in-house generated mouse fibroblast cell line expressing a reporter gene under the control of estrogen responsive sequences (EREs). 3D cell culture conditions were obtained in a Rotary Cell Culture System; (RCCS™), a microgravity based bioreactor that promotes the aggregation of cells into multicellular spheroids (MCS). In this bioreactor the cells maintained a better differentiated phenotype and more closely resembled in vivo tissue. The RCCS™ cultured fibroblasts showed higher expression of genes regulating cell assembly, differentiation and hormonal functions. Microarray analysis showed that genes related tomore » cell cycle, proliferation, cytoskeleton, migration, adhesion and motility were all down-regulated in 3D as compared to 2D conditions, as well as oncogene expression and inflammatory cytokines. Controlled remodeling of ECM, which is an essential aspect of cell organization, homeostasis and tissue was affected by the culture method as assessed by immunolocalization of β-tubulin. Markers of cell organization, homeostasis and tissue repair, metalloproteinase 2 (MMP2) and its physiological inhibitor (TIMP4) changed expression in association with the relative formation of cell aggregates. The fibroblasts cultured in the RCCS™ maintain a better responsiveness to estrogens, measured as expression of ERα and regulation of an ERE-dependent reporter and of the endogenous target genes CBP, Rarb, MMP1 and Dbp. Our data highlight the interest of this 3D culture model for its potential application in the field of cell response to hormonal signals and the pharmaco-toxicological analyses of chemicals and natural molecules endowed of estrogenic potential. - Highlights: • We here characterized the first cell line derived from an estrogen reporter mouse. • In the RCCS cells express an immortalized behavior but not a transformed phenotype. • The RCCS provides a system for maintaining cells in more physiological conditions. • RCCS-cultured fibroblasts showed higher hormonal sensitivity to estradiol. • This bioreactor is a novel 3D model to be applied to pharmacotoxicological studies.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bae, Sijeong; Kwon, Hwang; Yoon, Hyemin

The sine oculis homeobox 1 (SIX1) is a member of the Six gene family. SIX1 is involved in tissue development by regulating proliferation, apoptosis, and differentiation. However, function of SIX1 in the uterus remains unknown. Here, we found that Six1 expression is regulated along the estrous cycle in mouse uterus. Six1 expression was significantly increased at estrus stage and decreased at the rest of stages. SIX1 is detected in the luminal and glandular epithelium of uterine endometrium at the estrus stage. Estrogen injection increased Six1 expression in the ovariectomized mouse uterus, whereas progesterone had no effect on its expression. Estrogenmore » receptor antagonist inhibited estrogen-induced Six1 expression. Our findings imply that SIX1 may play a role as an important regulator to orchestrate the dynamic of uterine endometrium in response to estrogen level during the estrous cycle. These results will give us a better understanding of uterine biology. - Highlights: • Six1 expression is regulated during the estrous cycle in mouse uterus. • Six1 is highly expressed at the estrus stage of estrous cycle. • SIX1 is detected in luminal/glandular epithelium of the uterus at the estrus stage. • Estrogen stimulates Six1 expression in an estrogen receptor-dependent manner.« less

Sexual Dimorphism and Estrogen Action in Mouse Liver.

PubMed

Torre, Della; Lolli, Federica; Ciana, Paolo; Maggi, Adriana

2017-01-01

Recent studies have demonstrated that in mice, the estrogen receptor alpha (ERα) is expressed in the liver and has a direct effect on the regulation of the hepatic genes relevant for energy metabolism and drug metabolism. The sex-related differential expression of the hepatic ERα raises the questions as to whether this receptor is responsible for the sexual differences observed in the physiopathology of the liver.

Aging, estradiol and time of day differentially affect serotonin transporter binding in the central nervous system of female rats.

PubMed

Krajnak, Kristine; Rosewell, Katherine L; Duncan, Marilyn J; Wise, Phyllis M

2003-11-14

Estrogen-related changes in serotonergic neuronal transmission, including changes in the number of serotonin transporter (SERT) binding sites, have been cited as a possible cause for changes in mood, memory and sleep that occur during the menopausal transition. However, both aging and estradiol regulate SERT binding sites in the brain. The goal of this experiment was to determine how aging and estrogen interact to regulate SERT levels in the forebrain of young and reproductively senescent female Sprague-Dawley rats using [3H]paroxetine. The density of specific [3H]paroxetine binding in various brain regions was compared in young (2-4 months) and reproductively senescent (10-12 months) female rats at three times of day. In most brain regions examined, estrogen and aging independently increased the number of [3H]paroxetine binding sites. The only region that displayed a reduction in [3H]paroxetine binding with age was the suprachiasmatic nucleus (SCN). Time of day influenced [3H]paroxetine binding in the SCN and the paraventricular thalamus (PVT), two regions known to be involved in the regulation of circadian rhythms. Aging and/or estrogen also altered the pattern of binding in these regions. Thus, based on the results of this study, we conclude that aging and estrogen both act to regulate SERT binding sites in the forebrain of female rats, and that this regulation is region specific.

Estrogen promotes megakaryocyte polyploidization via estrogen receptor beta-mediated transcription of GATA1.

PubMed

Du, C; Xu, Y; Yang, K; Chen, S; Wang, X; Wang, S; Wang, C; Shen, M; Chen, F; Chen, M; Zeng, D; Li, F; Wang, T; Wang, F; Zhao, J; Ai, G; Cheng, T; Su, Y; Wang, J

2017-04-01

Estrogen is reported to be involved in thrombopoiesis and the disruption of its signaling may cause myeloproliferative disease, yet the underlying mechanisms remain largely unknown. GATA-binding factor 1 (GATA1) is a key regulator of megakaryocyte (MK) differentiation and its deficiency will lead to megakaryoblastic leukemia. Here we show that estrogen can dose-dependently promote MK polyploidization and maturation via activation of estrogen receptor beta (ERβ), accompanied by a significant upregulation of GATA1. Chromatin immunoprecipitation and a dual luciferase assay demonstrate that ERβ can directly bind the promoter region of GATA1 and activate its transcription. Steroid receptor coactivator 3 (SRC3) is involved in ERβ-mediated GATA1 transcription. The deficiency of ERβ or SRC3, similar to the inhibition of GATA1, leads to the impediment of estrogen-induced MK polyploidization and platelet production. Further investigations reveal that signal transducer and activator of transcription 1 signaling pathway downstream of GATA1 has a crucial role in estrogen-induced MK polyploidization, and ERβ-mediated GATA1 upregulation subsequently enhances nuclear factor erythroid-derived 2 expression, thereby promoting proplatelet formation and platelet release. Our study provides a deep insight into the molecular mechanisms of estrogen signaling in regulating thrombopoiesis and the pathogenesis of ER deficiency-related leukemia.

17β-estradiol regulates the differentiation of cementoblasts via Notch signaling cascade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liao, Jing; Zhou, Zeyuan; Huang, Li

Estrogen has been well recognized as a key factor in the homeostasis of bone and periodontal tissue, but the way it regulates the activities of cementoblasts, the cell population maintaining cementum has not been fully understood. In this study, we examined the expression of estrogen receptor in OCCM-30 cells and the effect of 17β-estradiol (E2) on the proliferation and differentiation of OCCM-30 cells. We found that both estrogen receptor α and β were expressed in OCCM-30 cells. E2 exerted no significant influence on the proliferation of OCCM-30 cells, but inhibited the transcription and translation of BSP and Runx2 in the early phase of osteogenicmore » induction except the BSP mRNA. Afterwards in the late phase of osteogenic induction, E2 enhanced the transcription and translation of BSP and Runx2 and promoted the calcium deposition. In addition, the expression level of Notch1, NICD and Hey1 mRNAs responded to exogenous E2 in a pattern similar to that of the osteoblastic markers. DAPT could attenuate the effect of E2 on the expression of osteoblastic markers. These findings indicated that E2 might regulate the differentiation of cementoblasts via Notch signaling. - Highlights: • 17β-estradiol showed no significant effect on the proliferation of cementoblasts. • 17β-estradiol promoted the osteoblastic differentiation of cementoblasts despite of an early transient inhibition. • Notch signaling was regulated by 17β-estradiol and was responsible for mediating the effect of E2 on cementoblasts. • Hey1 might display an opposite expression pattern to Notch signaling in certain circumstances.« less

Neuro-estrogens rapidly regulate sexual motivation but not performance

PubMed Central

Seredynski, Aurore L.; Balthazart, Jacques; Christophe, Virginie J.; Ball, Gregory F.; Cornil, Charlotte A.

2013-01-01

Estrogens exert pleiotropic effects on reproductive traits, which include differentiation and activation of reproductive behaviors and the control of the secretion of gonadotropins. Estrogens also profoundly affect non-reproductive traits such as cognition and neuroprotection. These effects are usually attributed to nuclear receptor binding and subsequent regulation of target gene transcription. Estrogens also affect neuronal activity and cell-signaling pathways via faster, membrane-initiated events. How these two types of actions that operate in distinct time scales interact in the control of complex behavioral responses is poorly understood. Here, we show that the central administration of estradiol rapidly increases the expression of sexual motivation, as assessed by several measures of sexual motivation produced in response to the visual presentation of a female but not sexual performance in male Japanese quail. This effect is mimicked by membrane-impermeable analogs of estradiol, indicating that it is initiated at the cell membrane. Conversely, blocking the action of estrogens or their synthesis by a single intracereboventricular injection of estrogen receptor antagonists or aromatase inhibitors respectively decreases sexual motivation within minutes without affecting performance. The same steroid has thus evolved complementary mechanisms to regulate different behavioral components (motivation vs. performance) in distinct temporal domains (long- vs. short-term) so that diverse reproductive activities can be properly coordinated to improve reproductive fitness. Given the pleiotropic effects exerted by estrogens, other responses controlled by these steroids might also depend on a slow genomic regulation of neuronal plasticity underlying behavioral activation and an acute control of motivation to engage in behavior. PMID:23283331

Extracellular matrix metalloproteinase inducer expression in the baboon endometrium: menstrual cycle and endometriosis

PubMed Central

Braundmeier, A G; Fazleabas, A T; Nowak, R A

2016-01-01

Extracellular matrix metalloproteinase inducer (EMMPRIN; BSG) regulates tissue remodeling through matrix metalloproteinases (MMPs). In human and non-human primates, endometrial remodeling is important for menstruation and the pathogenesis of endometriosis. We hypothesized that as in humans, BSG and MMPs are expressed in the endometrium of cycling baboons, and their expression is hormonally regulated by ovarian hormones, but endometriosis disrupts this regulation. BSG expression was evaluated in the baboon endometrium by q-PCR and immunohistochemistry. In the endometrium of control cycling animals, BSG mRNA levels were highest in late secretory stage tissue. BSG protein localized to glandular epithelial cells during the proliferative phase; whereas, secretory stage tissues expressed BSG in glandular and luminal epithelia with weak stromal staining. Several MMPs were differentially expressed throughout the menstrual cycle with the highest levels found during menstruation. In ovariectomized animals, BSG endometrial mRNA levels were highest with treatment of both estrogen and progesterone than that with only estrogen. Estrogen alone resulted in BSG protein localization primarily in the endometrial glandular epithelia, while estrogen and progesterone treatment displayed BSG protein localization in both the glandular and stromal cells. Exogenous hormone treatment resulted in differential expression patterns of all MMPs compared with the control cycling animals. In the eutopic endometrium of endometriotic animals, BSG mRNA levels and protein were elevated early but decreased later in disease progression. Endometriosis elevated the expression of all MMPs except MMP7 compared with the control animals. In baboons, BSG and MMP endometrial expression is regulated by both ovarian hormones, and their expression patterns are dysregulated in endometriotic animals. PMID:20841363

Estrogen-related receptor {alpha} modulates the expression of adipogenesis-related genes during adipocyte differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko

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 acidmore » 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.« less

AHCYL1 Is Mediated by Estrogen-Induced ERK1/2 MAPK Cell Signaling and MicroRNA Regulation to Effect Functional Aspects of the Avian Oviduct

PubMed Central

Ahn, Suzie E.; Lee, Sang In; Bazer, Fuller W.; Han, Jae Yong; Song, Gwonhwa

2012-01-01

S-adenosylhomocysteine hydrolase-like protein 1 (AHCYL1), also known as IP3 receptor-binding protein released with IP3 (IRBIT), regulates IP3-induced Ca2+ release into the cytoplasm of cells. AHCYL1 is a critical regulator of early developmental stages in zebrafish, but little is known about the function of AHCYL1 or hormonal regulation of expression of the AHCYL1 gene in avian species. Therefore, we investigated differential expression profiles of the AHCYL1 gene in various adult organs and in oviducts from estrogen-treated chickens. Chicken AHCYL1 encodes for a protein of 540 amino acids that is highly conserved and has considerable homology to mammalian AHCYL1 proteins (>94% identity). AHCYL1 mRNA was expressed abundantly in various organs of chickens. Further, the synthetic estrogen agonist induced AHCYL1 mRNA and protein predominantly in luminal and glandular epithelial cells of the chick oviduct. In addition, estrogen activated AHCYL1 through the ERK1/2 signal transduction cascade and that activated expression of AHCYL1 regulated genes affecting oviduct development in chicks as well as calcium release in epithelial cells of the oviduct. Also, microRNAs, miR-124a, miR-1669, miR-1710 and miR-1782 influenced AHCYL1 expression in vitro via its 3′-UTR which suggests that post-transcriptional events are involved in the regulation of AHCYL1 expression in the chick oviduct. In conclusion, these results indicate that AHCYL1 is a novel estrogen-stimulated gene expressed in epithelial cells of the chicken oviduct that likely affects growth, development and calcium metabolism of the mature oviduct of hens via an estrogen-mediated ERK1/2 MAPK cell signaling pathway. PMID:23145124

Estrogen-Induced Maldevelopment of the Penis Involves Down-Regulation of Myosin Heavy Chain 11 (MYH11) Expression, a Biomarker for Smooth Muscle Cell Differentiation1

PubMed Central

Okumu, L.A.; Bruinton, Sequoia; Braden, Tim D.; Simon, Liz; Goyal, Hari O.

2012-01-01

ABSTRACT Cavernous smooth muscle cells are essential components in penile erection. In this study, we investigated effects of estrogen exposure on biomarkers for smooth muscle cell differentiation in the penis. Neonatal rats received diethylstilbestrol (DES), with or without the estrogen receptor (ESR) antagonist ICI 182,780 (ICI) or the androgen receptor (AR) agonist dihydrotestosterone (DHT), from Postnatal Days 1 to 6. Tissues were collected at 7, 10, or 21 days of age. The smooth muscle cell biomarker MYH11 was studied in depth because microarray data showed it was significantly down-regulated, along with other biomarkers, in DES treatment. Quantitative real time-PCR and Western blot analyses showed 50%–80% reduction (P ≤ 0.05) in Myh11 expression in DES-treated rats compared to that in controls; and ICI and DHT coadministration mitigated the decrease. Temporally, from 7 to 21 days of age, Myh11 expression was onefold increased (P ≥ 0.05) in DES-treated rats versus threefold increased (P ≤ 0.001) in controls, implying the long-lasting inhibitory effect of DES on smooth muscle cell differentiation. Immunohistochemical localization of smooth muscle alpha actin, another biomarker for smooth muscle cell differentiation, showed fewer cavernous smooth muscle cells in DES-treated animals than in controls. Additionally, DES treatment significantly up-regulated Esr1 mRNA expression and suppressed the neonatal testosterone surge by 90%, which was mitigated by ICI coadministration but not by DHT coadministration. Collectively, results provided evidence that DES treatment in neonatal rats inhibited cavernous smooth muscle cell differentiation, as shown by down-regulation of MYH11 expression at the mRNA and protein levels and by reduced immunohistochemical staining of smooth muscle alpha actin. Both the ESR and the AR pathways probably mediate this effect. PMID:22976277

Differential neonatal imprinting and regulation by estrogen of estrogen receptor subtypes alpha and beta and of the truncated estrogen receptor product (TERP-1) mRNA expression in the male rat pituitary.

PubMed

Tena-Sempere, M; Barreiro, M L; González, L C; Pinilla, L; Aguilar, E

2001-11-01

Two distinct nuclear estrogen receptors (ERs) have been identified, the classical one, renamed ERalpha, and the more recently cloned ERbeta. In a variety of tissues, gene expression of both receptor subtypes results in the generation of multiple transcripts encoding the full-length as well as several alternately spliced isoforms. In the rat pituitary, a truncated, tissue-specific variant of ERalpha, called TERP-1, has been identified and found able to modulate ERalpha and ERbeta activity. So far, its pattern of expression and hormonal regulation have been mostly studied in females. The present study was designed to analyze the pattern of expression of TERP-1 mRNA in the male rat pituitary at different stages of postnatal development, and to evaluate the impact of neonatal imprinting and estrogen treatment upon TERP-1 expression in the male pituitary. Assessment of TERP-1 mRNA levels by semi-quantitative RT-PCR, using a variant-specific primer pair, revealed that TERP-1 is also expressed in the male rat pituitary. Relative mRNA expression levels changed markedly during postnatal development, with moderate expression of the TERP-1 transcript at birth, barely detectable levels during the infantile-prepubertal period, and maximal values in adulthood. Expression of TERP-1 was sensitive to neonatal estrogen exposure, which resulted in a significant, persistent increase in mRNA levels from the infantile period until puberty. This phenomenon was not mimicked by neonatal blockade of endogenous GnRH. In addition, estrogen was able to acutely up-regulate pituitary TERP-1 mRNA expression levels in prepubertal (30-day-old) and adult (75-day-old) males. Interestingly, neonatal imprinting as well as acute estrogen treatment resulted in opposite effects on TERP-1 and full-length ERalpha and ERbeta transcripts, the latter being decreased under both conditions. In conclusion, our data indicate that TERP-1 mRNA is expressed in a developmentally regulated manner in the male rat pituitary, and is affected by neonatal estrogen imprinting and acute estrogen treatment. Regulation of TERP-1 expression by neonatal or acute estrogen treatment may thus represent an additional tuning mechanism for estrogen actions in the male rat pituitary. Copyright 2001 S. Karger AG, Basel

GPER mediates the inhibitory actions of estrogen on adipogenesis in 3T3-L1 cells through perturbation of mitotic clonal expansion.

PubMed

Zhu, Pei; Yuen, Jacky M L; Sham, Kathy W Y; Cheng, Christopher H K

2013-11-01

G-protein-coupled estrogen receptor 1 (GPER) mediates non-genomic signaling of estrogenic events. Here we showed for the first time that Gper/GPER is expressed in Swiss 3T3 mouse embryo preadipocytes 3T3-L1, and that Gper/GPER is up-regulated during differentiation of the cells induced by monocyte differentiation-inducing (MDI) cocktail. Activation of GPER by the natural ligand 17β-estradiol (E2), and the specific agonist G1, was shown to inhibit lipid accumulation in 3T3-L1 cells, while such inhibition was reversed upon knockdown of GPER using specific siRNA. GPER was also found to mediate perturbation of mitotic clonal expansion (MCE) in these cells by inhibiting cell cycle arrest during MDI cocktail-induced differentiation. Persistent activation of cell cycle regulating factors cyclin-dependant kinase (CDK) 4, CDK6 and cyclin D1, and phosphorylation of retinoblastoma (Rb) protein at serine 795 was observed in the G1-treated cells. Taken together, our results indicate that E2-GPER signaling leads to an inhibition of adipogenesis in 3T3-L1 cells via perturbation of MCE. Copyright © 2013 Elsevier Inc. All rights reserved.

Conditional expression of constitutively active estrogen receptor {alpha} in chondrocytes impairs longitudinal bone growth in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ikeda, Kazuhiro; Tsukui, Tohru; Imazawa, Yukiko

2012-09-07

Highlights: Black-Right-Pointing-Pointer Conditional transgenic mice expressing constitutively active estrogen receptor {alpha} (caER{alpha}) in chondrocytes were developed. Black-Right-Pointing-Pointer Expression of caER{alpha} in chondrocytes impaired longitudinal bone growth in mice. Black-Right-Pointing-Pointer caER{alpha} affects chondrocyte proliferation and differentiation. Black-Right-Pointing-Pointer This mouse model is useful for understanding the physiological role of ER{alpha}in vivo. -- Abstract: Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caER{alpha}{sup ColII}, expressing constitutively activemore » mutant estrogen receptor (ER) {alpha} in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caER{alpha}{sup ColII} mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caER{alpha}{sup ColII} mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caER{alpha}{sup ColII} mice. These results suggest that ER{alpha} is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.« less

Androgens and estrogens in benign prostatic hyperplasia: past, present and future

PubMed Central

Nicholson, Tristan M.; Ricke, William A.

2011-01-01

Benign prostatic hyperplasia (BPH) and associated lower urinary tract symptoms (LUTS) are common clinical problems in urology. While the precise molecular etiology remains unclear, sex steroids have been implicated in the development and maintenance of BPH. Sufficient data exists linking androgens and androgen receptor pathways to BPH and use of androgen reducing compounds, such as 5α-reductase inhibitors which block the conversion of testosterone into dihydrotestosterone, are a component of the standard of care for men with LUTS attributed to an enlarged prostate. However, BPH is a multifactorial disease and not all men respond well to currently available treatments, suggesting factors other than androgens are involved. Testosterone, the primary circulating androgen in men, can also be metabolized via CYP19/aromatase into the potent estrogen, estradiol-17β. The prostate is an estrogen target tissue and estrogens directly and indirectly affect growth and differentiation of prostate. The precise role of endogenous and exogenous estrogens in directly affecting prostate growth and differentiation in the context of BPH is an understudied area. Estrogens and selective estrogen receptor modulators (SERMs) have been shown to promote or inhibit prostate proliferation signifying potential roles in BPH. Recent research has demonstrated that estrogen receptor signaling pathways may be important in the development and maintenance of BPH and LUTS; however, new models are needed to genetically dissect estrogen regulated molecular mechanisms involved in BPH. More work is needed to identify estrogens and associated signaling pathways in BPH in order to target BPH with dietary and therapeutic SERMs. PMID:21620560

17β-Estradiol regulates cyclin A1 and cyclin B1 gene expression in adult rat seminiferous tubules.

PubMed

Bois, Camille; Delalande, Christelle; Bouraïma-Lelong, Hélène; Durand, Philippe; Carreau, Serge

2012-04-01

Spermatogenesis, which is the fundamental mechanism allowing male gamete production, is controlled by several factors, and among them, estrogens are likely concerned. In order to enlighten the potential role of estrogen in rat spermatogenesis, seminiferous tubules (ST) from two groups of seminiferous epithelium stages (II-VIII and IX-I) were treated with either 17β-estradiol (E(2)) agonists or antagonists for estrogen receptors (ESRs). In this study, we show that cyclin A1 and cyclin B1 gene expression is controlled by E(2) at a concentration of 10(-9) M only in stages IX-I. This effect is mimicked by a treatment with the G-protein coupled estrogen receptor (GPER) agonist G1 and is abolished by treatment with the ESR antagonist ICI 182 780. Moreover, using letrozole, a drug that blocks estrogen synthesis, we demonstrate that these genes are under the control of E(2) within rat ST. Thus, germ cell differentiation may be regulated by E(2) which acts through ESRs and GPER, expressed in adult rat ST.

Distinct Effects of Estrogen on Mouse Maternal Behavior: The Contribution of Estrogen Synthesis in the Brain

PubMed Central

Murakami, Gen

2016-01-01

Estrogen surge following progesterone withdrawal at parturition plays an important role in initiating maternal behavior in various rodent species. Systemic estrogen treatment shortens the latency to onset of maternal behavior in nulliparous female rats that have not experienced parturition. In contrast, nulliparous laboratory mice show rapid onset of maternal behavior without estrogen treatment, and the role of estrogen still remains unclear. Here the effect of systemic estrogen treatment (for 2 h, 1 day, 3 days, and 7 days) after progesterone withdrawal was examined on maternal behavior of C57BL/6 mice. This estrogen regimen led to different effects on nursing, pup retrieval, and nest building behaviors. Latency to nursing was shortened by estrogen treatment within 2 h. Moreover, pup retrieval and nest building were decreased. mRNA expression was also investigated for estrogen receptor α (ERα) and for genes involved in regulating maternal behavior, specifically, the oxytocin receptor (OTR) and vasopressin receptor in the medial amygdala (MeA) and medial preoptic area (MPOA). Estrogen treatment led to decreased ERα mRNA in both regions. Although OTR mRNA was increased in the MeA, OTR and vasopressin receptor mRNA were reduced in the MPOA, showing region-dependent transcription regulation. To determine the mechanisms for the actions of estrogen treatment, the contribution of estrogen synthesis in the brain was examined. Blockade of estrogen synthesis in the brain by systemic letrozole treatment in ovariectomized mice interfered with pup retrieval and nest building but not nursing behavior, indicating different contributions of estrogen synthesis to maternal behavior. Furthermore, letrozole treatment led to an increase in ERα mRNA in the MeA but not in the MPOA, suggesting that involvement of estrogen synthesis is brain region dependent. Altogether, these results suggest that region-dependent estrogen synthesis leads to differential transcriptional activation due to exogenous estrogen treatment, and thereby results in different effects on maternal behavior. PMID:27007402

Signaling, physiological functions and clinical relevance of the G protein-coupled estrogen receptor GPER.

PubMed

Prossnitz, Eric R; Barton, Matthias

2009-09-01

GPR30, now named GPER1 (G protein-coupled estrogen receptor1) or GPER here, was first identified as an orphan 7-transmembrane G protein-coupled receptor by multiple laboratories using either homology cloning or differential expression and subsequently shown to be required for estrogen-mediated signaling in certain cancer cells. The actions of estrogen are extensive in the body and are thought to be mediated predominantly by classical nuclear estrogen receptors that act as transcription factors/regulators. Nevertheless, certain aspects of estrogen function remain incompatible with the generally accepted mechanisms of classical estrogen receptor action. Many recent studies have revealed that GPER contributes to some of the actions of estrogen, including rapid signaling events and rapid transcriptional activation. With the introduction of GPER-selective ligands and GPER knockout mice, the functions of GPER are becoming more clearly defined. In many cases, there appears to be a complex interplay between the two receptor systems, suggesting that estrogen-mediated physiological responses may be mediated by either receptor or a combination of both receptor types, with important medical implications.

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.

The effects of dexamethasone, ascorbic acid, and β-glycerophosphate on osteoblastic differentiation by regulating estrogen receptor and osteopontin expression.

PubMed

Park, Jun-Beom

2012-03-01

Ascorbic acid (AA), β-glycerophosphate (GP), and dexamethasone (DEX) are the compounds known to favor the expression of the osteoblastic phenotype in several bone cell systems. In this report, the combination effects of differentiation agents on osteoprecursor cells were evaluated. The effect on cell proliferation was determined by a cell viability test with morphologic analysis. Differentiation and mineralization were evaluated using an alkaline phosphatase activity test and alizarin red-S staining. Protein expressions related to bone formation, such as transforming growth factor-beta (TGF-β), estrogen receptor-alpha (ER-α), and osteopontin (OPN) were evaluated by using a Western blot analysis. AA and GP provided an inductive effect for differentiation of osteoprecusor cells, while short-term application of DEX seemed to lead to a dose-dependent increase of cellular differentiation. Long-term use of DEX seemed to reduce mineralization. These effects may seem to be regulated by the expression of ER-α, OPN, and TGF-β. Further studies related to this mechanism within the in vivo model may be necessary to ascertain greater detail. Copyright © 2012 Elsevier Inc. All rights reserved.

Expression and regulation of aromatase and 17 beta-hydroxysteroid dehydrogenase type 4 in human THP 1 leukemia cells.

PubMed

Jakob, F; Homann, D; Adamski, J

1995-12-01

Estradiol is active in proliferation and differentiation of sex-related tissues like ovary and breast. Glandular steroid metabolism was for a long time believed to dominate the estrogenic milieu around any cell of the organism. Recent reports verified the expression of estrogen receptors in "non-target" tissues as well as the extraglandular expression of steroid metabolizing enzymes. Extraglandular steroid metabolism proved to be important in the brain, skin and in stromal cells of hormone responsive tumors. Aromatase converts testosterone into estradiol and androstenedione into estrone, thereby activating estrogen precursors. The group of 17 beta-hydroxysteroid dehydrogenases catalyzes the oxidation and/or reduction of the forementioned compounds, e.g. estradiol/estrone, thereby either activating or inactivating estradiol. Aromatase is expressed and regulated in the human THP 1 myeloid leukemia cell line after vitamin D/GMCSF-propagated differentiation. Aromatase expression is stimulated by dexamethasone, phorbolesters and granulocyte/macrophage stimulating factor (GMCSF). Exons I.2 and I.4 are expressed in PMA-stimulated cells only, exon I.3 in both PMA- and dexamethasone-stimulated cells. Vitamin D-differentiated THP 1 cells produce a net excess of estradiol in culture supernatants, if testosterone is given as aromatase substrate. In contrast, the 17 beta-hydroxysteroid dehydrogenase type 4 (17 beta-HSD 4) is abundantly expressed in unstimulated THP 1 cells and is further stimulated by glucocorticoids (2-fold). The expression is unchanged after vitamin D/GMCSF-propagated differentiation. 17 beta-HSD 4 expression is not altered by phorbolester treatment in undifferentiated cells but is abolished after vitamin D-propagated differentiation along with downregulation of beta-actin. Protein kinase C activation therefore appears to dissociate the expression of aromatase and 17 beta-HSD 4 in this differentiation stage along the monocyte/phagocyte pathway of THP 1 myeloid cells. The expression of steroid metabolizing enzymes in myeloid cells is able to create a microenvironment which is uncoupled from dominating systemic estrogens. These findings may be relevant in the autocrine, paracrine or iuxtacrine cellular crosstalk of myeloid cells in their respective states of terminal differentiation, e.g. in bone metabolism and inflammation.

Cloning and expression of R-Spondin1 in different vertebrates suggests a conserved role in ovarian development.

PubMed

Smith, Craig A; Shoemaker, Christina M; Roeszler, Kelly N; Queen, Joanna; Crews, David; Sinclair, Andrew H

2008-07-24

R-Spondin1 (Rspo1) is a novel regulator of the Wnt/beta-catenin signalling pathway. Loss-of-function mutations in human RSPO1 cause testicular differentiation in 46, XX females, pointing to a role in ovarian development. Here we report the cloning and comparative expression analysis of R-SPONDIN1 orthologues in the mouse, chicken and red-eared slider turtle, three species with different sex-determining mechanisms. Evidence is presented that this gene is an ancient component of the vertebrate ovary-determining pathway. Gonadal RSPO1 gene expression is female up-regulated in the embryonic gonads in each species at the onset of sexual differentiation. In the mouse gonad, Rspo1 mRNA is expressed in the somatic cell lineage at the time of ovarian differentiation (E12.5-E15.5), with little expression in germ cells. However, the protein is localised in the cytoplasm and at the cell surface of both somatic (pre-follicular) and germ cells. In the chicken embryo, RSPO1 expression becomes elevated in females at the time of ovarian differentiation, coinciding with female-specific activation of the FOXL2 gene and estrogen synthesis. RSPO1 protein in chicken is localised in the outer cortical zone of the developing ovary, the site of primordial follicle formation and germ cell differentiation. Inhibition of estrogen synthesis with a specific aromatase inhibitor results in a decline in chicken RSPO1 expression, indicating that RSPO1 is influenced by estrogen. In the red-eared slider turtle, which exhibits temperature-dependent sex determination, up-regulation of RSPO1 occurs during the temperature-sensitive period, when gonadal development is responsive to temperature. Accordingly, RSPO1 expression is temperature-responsive, and is down-regulated in embryos shifted from female- to male-producing incubation temperatures. These results indicate that RSPO1 is up-regulated in the embryonic gonads of female vertebrates with different sex-determining mechanisms. In all instances, RSPO1 is expressed in the incipient ovary. These findings suggest that R-SPONDIN1 is an ancient, conserved part of the vertebrate ovary-determining pathway.

Cloning and expression of R-Spondin1 in different vertebrates suggests a conserved role in ovarian development

PubMed Central

Smith, Craig A; Shoemaker, Christina M; Roeszler, Kelly N; Queen, Joanna; Crews, David; Sinclair, Andrew H

2008-01-01

Background R-Spondin1 (Rspo1) is a novel regulator of the Wnt/β-catenin signalling pathway. Loss-of-function mutations in human RSPO1 cause testicular differentiation in 46, XX females, pointing to a role in ovarian development. Here we report the cloning and comparative expression analysis of R-SPONDIN1 orthologues in the mouse, chicken and red-eared slider turtle, three species with different sex-determining mechanisms. Evidence is presented that this gene is an ancient component of the vertebrate ovary-determining pathway. Results Gonadal RSPO1 gene expression is female up-regulated in the embryonic gonads in each species at the onset of sexual differentiation. In the mouse gonad, Rspo1 mRNA is expressed in the somatic cell lineage at the time of ovarian differentiation (E12.5–E15.5), with little expression in germ cells. However, the protein is localised in the cytoplasm and at the cell surface of both somatic (pre-follicular) and germ cells. In the chicken embryo, RSPO1 expression becomes elevated in females at the time of ovarian differentiation, coinciding with female-specific activation of the FOXL2 gene and estrogen synthesis. RSPO1 protein in chicken is localised in the outer cortical zone of the developing ovary, the site of primordial follicle formation and germ cell differentiation. Inhibition of estrogen synthesis with a specific aromatase inhibitor results in a decline in chicken RSPO1 expression, indicating that RSPO1 is influenced by estrogen. In the red-eared slider turtle, which exhibits temperature-dependent sex determination, up-regulation of RSPO1 occurs during the temperature-sensitive period, when gonadal development is responsive to temperature. Accordingly, RSPO1 expression is temperature-responsive, and is down-regulated in embryos shifted from female- to male-producing incubation temperatures. Conclusion These results indicate that RSPO1 is up-regulated in the embryonic gonads of female vertebrates with different sex-determining mechanisms. In all instances, RSPO1 is expressed in the incipient ovary. These findings suggest that R-SPONDIN1 is an ancient, conserved part of the vertebrate ovary-determining pathway. PMID:18651984

Regulation of estrogen receptor beta mRNA in the brain: opposite effects of 17beta-estradiol and the phytoestrogen, coumestrol.

PubMed

Patisaul, H B; Whitten, P L; Young, L J

1999-04-06

Estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta) are differentially distributed in the brain and likely mediate different estrogen-dependent processes. ERbeta is abundant in the bed nucleus of the stria terminalis, medial preoptic nucleus, paraventricular nucleus of the hypothalamus and the amygdala of the rat. In the paraventricular nucleus, which is devoid of ERalpha, ERbeta is colocalized with the neuropeptides, oxytocin and vasopressin, suggesting a potential functional role for ERbeta in the regulation of these peptides. We examined the regulation of ERbeta mRNA expression in the rat brain by 17beta-estradiol and the phytoestrogen, coumestrol. 17beta-Estradiol treatment decreased ERbeta mRNA in situ hybridization signal by 44.5% in the paraventricular nucleus of the hypothalamus (PVN), but had no effect in the bed nucleus of the stria terminalis (BnST) or the medial preoptic nucleus (MPA). In contrast, dietary exposure to coumestrol increased ERbeta mRNA signal by 47.5% in the PVN but had no effect in the BnST or the MPA. These data demonstrate that like ERalpha, ERbeta is down regulated by estrogen in a region specific manner in the rat brain. Furthermore, exposure to coumestrol may modulate ERbeta-dependent processes by acting as an anti-estrogen at ERbeta. This data contradicts results from cell transfection assays which suggest an estrogenic activity of coumestrol on ERbeta, indicating that the mode of action may be tissue specific, or that metabolism of dietary coumestrol may alter its effects. Because the highest concentrations of phytoestrogens are found in legumes, vegetables and grains, they are most prevalent in vegetarian and traditional Asian diets. Understanding the neuroendocrine effects of phytoestrogens is particularly important now that they are being marketed as a natural alternative to estrogen replacement therapy and sold in highly concentrated pills and powders. Copyright 1999 Elsevier Science B.V.

Estrogen modulates mesenchyme-epidermis interactions in the adult nipple

PubMed Central

Wu, Hsing-Jung; Oh, Ji Won; Spandau, Dan F.; Tholpady, Sunil; Diaz, Jesus; Schroeder, Laura J.; Offutt, Carlos D.; Glick, Adam B.; Plikus, Maksim V.; Koyama, Sachiko

2017-01-01

Maintenance of specialized epidermis requires signals from the underlying mesenchyme; however, the specific pathways involved remain to be identified. By recombining cells from the ventral skin of the K14-PTHrP transgenic mice [which overexpress parathyroid hormone-related protein (PTHrP) in their developing epidermis and mammary glands] with those from wild type, we show that transgenic stroma is sufficient to reprogram wild-type keratinocytes into nipple-like epidermis. To identify candidate nipple-specific signaling factors, we compared gene expression signatures of sorted Pdgfrα-positive ventral K14-PTHrP and wild-type fibroblasts, identifying differentially expressed transcripts that are involved in WNT, HGF, TGFβ, IGF, BMP, FGF and estrogen signaling. Considering that some of the growth factor pathways are targets for estrogen regulation, we examined the upstream role of this hormone in maintaining the nipple. Ablation of estrogen signaling through ovariectomy produced nipples with abnormally thin epidermis, and we identified TGFβ as a negatively regulated target of estrogen signaling. Estrogen treatment represses Tgfβ1 at the transcript and protein levels in K14-PTHrP fibroblasts in vitro, while ovariectomy increases Tgfb1 levels in K14-PTHrP ventral skin. Moreover, ectopic delivery of Tgfβ1 protein into nipple connective tissue reduced epidermal proliferation. Taken together, these results show that specialized nipple epidermis is maintained by estrogen-induced repression of TGFβ signaling in the local fibroblasts. PMID:28289136

Distinct Signaling Pathways Mediate Stimulation of Cell Cycle Progression and Prevention of Apoptotic Cell Death by Estrogen in Rat Pituitary Tumor PR1 Cells

PubMed Central

Caporali, Simona; Imai, Manami; Altucci, Lucia; Cancemi, Massimo; Caristi, Silvana; Cicatiello, Luigi; Matarese, Filomena; Penta, Roberta; Sarkar, Dipak K.; Bresciani, Francesco; Weisz, Alessandro

2003-01-01

Estrogens control cell growth and viability in target cells via an interplay of genomic and extragenomic pathways not yet elucidated. Here, we show evidence that cell proliferation and survival are differentially regulated by estrogen in rat pituitary tumor PR1 cells. Pico- to femtomolar concentrations of 17β-estradiol (E2) are sufficient to foster PR1 cell proliferation, whereas nanomolar concentrations of the same are needed to prevent cell death that occurs at a high rate in these cells in the absence of hormone. Activation of endogenous (PRL) or transfected estrogen-responsive genes occurs at the same, higher concentrations of E2 required to promote cell survival, whereas stimulation of cyclin D3 expression and DNA synthesis occur at lower E2 concentrations. Similarly, the pure antiestrogen ICI 182,780 inhibits estrogen response element-dependent trans-activation and cell death more effectively than cyclin-cdk activity, G1-S transition, or DNA synthesis rate. In antiestrogen-treated and/or estrogen-deprived cells, death is due predominantly to apoptosis. Estrogen-induced cell survival, but not E2-dependent cell cycle progression, can be prevented by an inhibitor of c-Src kinase or by blockade of the mitogen-activated protein kinase kinase/extracellular signal-regulated kinase signaling pathway. These data indicate the coexistence of two distinguishable estrogen signaling pathways in PR1 cells, characterized by different functions and sensitivity to hormones and antihormones. PMID:12960425

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

PubMed

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

2014-09-01

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. Published by Elsevier Ltd.

Role of Estrogens in the Regulation of Liver Lipid Metabolism.

PubMed

Palmisano, Brian T; Zhu, Lin; Stafford, John M

2017-01-01

Before menopause, women are protected from atherosclerotic heart disease associated with obesity relative to men. Sex hormones have been proposed as a mechanism that differentiates this risk. In this review, we discuss the literature around how the endogenous sex hormones and hormone treatment approaches after menopause regulate fatty acid, triglyceride, and cholesterol metabolism to influence cardiovascular risk.The important regulatory functions of estrogen signaling pathways with regard to lipid metabolism have been in part obscured by clinical trials with hormone treatment of women after menopause, due to different formulations, routes of delivery, and pairings with progestins. Oral hormone treatment with several estrogen preparations increases VLDL triglyceride production. Progestins oppose this effect by stimulating VLDL clearance in both humans and animals. Transdermal estradiol preparations do not increase VLDL production or serum triglycerides.Many aspects of sex differences in atherosclerotic heart disease risk are influenced by the distributed actions of estrogens in the muscle, adipose, and liver. In humans, 17β-estradiol (E2) is the predominant circulating estrogen and signals through estrogen receptor alpha (ERα), estrogen receptor beta (ERβ), and G-protein-coupled estrogen receptor (GPER). Over 1000 human liver genes display a sex bias in their expression, and the top biological pathways are in lipid metabolism and genes related to cardiovascular disease. Many of these genes display variation depending on estrus cycling in the mouse. Future directions will likely rely on targeting estrogens to specific tissues or specific aspects of the signaling pathways in order to recapitulate the protective physiology of premenopause therapeutically after menopause.

Differential role of the estrogen receptors ESR1 and ESR2 on the regulation of proteins involved with proliferation and differentiation of Sertoli cells from 15-day-old rats.

PubMed

Lucas, Thaís F G; Lazari, Maria Fatima M; Porto, Catarina S

2014-01-25

The aim of the present study was to investigate the role of each estrogen receptors on the regulation of proteins involved with proliferation and differentiation of Sertoli cells from 15-day-old rats. Activation of ESR1 by 17β-estradiol (E2) and ESR1-selective agonist PPT increased CCND1 expression, and this effect was dependent on NF-kB activation. E2 and the ESR2-selective agonist DPN, but not PPT, increased, in a PI3K and CREB-dependent manner, the expression of CDKN1B and the transcription factors GATA-1 and DMRT1. Analyzing the expression of ESR1 and ESR2 in different stages of development of Sertoli cells, we observed that the ESR1/ESR2 ratio decreased with age, and this ratio seems to be important to determine the end of cell proliferation and the start of cell differentiation. In Sertoli cells from 15-day-old rats, the ESR1/ESR2 ratio favors the effect of ESR1 and the activation of this receptor increased [Methyl-(3)H]thymidine incorporation. We propose that in Sertoli cells from 15-day-old rats E2 modulates Sertoli cell proliferation through ESR1/NF-kB-mediated increase of CCND1, and cell cycle exit and differentiation through ESR2/CREB-mediated increase of CDKN1B, GATA-1 and DMRT1. The present study reinforces the important role of estrogen for normal testis development. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Calmodulin-like protein 3 is an estrogen receptor alpha coregulator for gene expression and drug response in a SNP, estrogen, and SERM-dependent fashion.

PubMed

Qin, Sisi; Ingle, James N; Liu, Mohan; Yu, Jia; Wickerham, D Lawrence; Kubo, Michiaki; Weinshilboum, Richard M; Wang, Liewei

2017-08-18

We previously performed a case-control genome-wide association study in women treated with selective estrogen receptor modulators (SERMs) for breast cancer prevention and identified single nucleotide polymorphisms (SNPs) in ZNF423 as potential biomarkers for response to SERM therapy. The ZNF423rs9940645 SNP, which is approximately 200 bp away from the estrogen response elements, resulted in the SNP, estrogen, and SERM-dependent regulation of ZNF423 expression and, "downstream", that of BRCA1. Electrophoretic mobility shift assay-mass spectrometry was performed to identify proteins binding to the ZNF423 SNP and coordinating with estrogen receptor alpha (ERα). Clustered, regularly interspaced short palindromic repeats (CRISPR)/Cas9 genome editing was applied to generate ZR75-1 breast cancer cells with different ZNF423 SNP genotypes. Both cultured cells and mouse xenograft models with different ZNF423 SNP genotypes were used to study the cellular responses to SERMs and poly(ADP-ribose) polymerase (PARP) inhibitors. We identified calmodulin-like protein 3 (CALML3) as a key sensor of this SNP and a coregulator of ERα, which contributes to differential gene transcription regulation in an estrogen and SERM-dependent fashion. Furthermore, using CRISPR/Cas9-engineered ZR75-1 breast cancer cells with different ZNF423 SNP genotypes, striking differences in cellular responses to SERMs and PARP inhibitors, alone or in combination, were observed not only in cells but also in a mouse xenograft model. Our results have demonstrated the mechanism by which the ZNF423 rs9940645 SNP might regulate gene expression and drug response as well as its potential role in achieving more highly individualized breast cancer therapy.

Estrogen signaling selectively induces apoptosis of hematopoietic progenitors and myeloid neoplasms without harming steady-state hematopoiesis.

PubMed

Sánchez-Aguilera, Abel; Arranz, Lorena; Martín-Pérez, Daniel; García-García, Andrés; Stavropoulou, Vaia; Kubovcakova, Lucia; Isern, Joan; Martín-Salamanca, Sandra; Langa, Xavier; Skoda, Radek C; Schwaller, Jürg; Méndez-Ferrer, Simón

2014-12-04

Estrogens are potent regulators of mature hematopoietic cells; however, their effects on primitive and malignant hematopoietic cells remain unclear. Using genetic and pharmacological approaches, we observed differential expression and function of estrogen receptors (ERs) in hematopoietic stem cell (HSC) and progenitor subsets. ERα activation with the selective ER modulator (SERM) tamoxifen induced apoptosis in short-term HSCs and multipotent progenitors. In contrast, tamoxifen induced proliferation of quiescent long-term HSCs, altered the expression of self-renewal genes, and compromised hematopoietic reconstitution after myelotoxic stress, which was reversible. In mice, tamoxifen treatment blocked development of JAK2(V617F)-induced myeloproliferative neoplasm in vivo, induced apoptosis of human JAK2(V617F+) HSPCs in a xenograft model, and sensitized MLL-AF9(+) leukemias to chemotherapy. Apoptosis was selectively observed in mutant cells, and tamoxifen treatment only had a minor impact on steady-state hematopoiesis in disease-free animals. Together, these results uncover specific regulation of hematopoietic progenitors by estrogens and potential antileukemic properties of SERMs. Copyright © 2014 Elsevier Inc. All rights reserved.

Sex steroids and the GH axis: Implications for the management of hypopituitarism.

PubMed

Birzniece, Vita; Ho, Ken K Y

2017-02-01

Growth hormone (GH) regulates somatic growth, substrate metabolism and body composition. Sex hormones exert profound effect on the secretion and action of GH. Estrogens stimulate the secretion of GH, but inhibit the action of GH on the liver, an effect that occurs when administered orally. Estrogens suppress GH receptor signaling by stimulating the expression proteins that inhibit cytokine receptor signaling. This effect of estrogens is avoided when physiological doses of estrogens are administered via a non-oral route. Estrogen-like compounds, such as selective estrogen receptor modulators, possess dual properties of inhibiting the secretion as well as the action of GH. In contrast, androgens stimulate GH secretion, driving IGF-1 production. In the periphery, androgens enhance the action of GH. The differential effects of estrogens and androgens influence the dose of GH replacement in patients with hypopituitarism on concomitant treatment with sex steroids. Where possible, a non-oral route of estrogen replacement is recommended for optimizing cost-benefit of GH replacement in women with GH deficiency. Adequate androgen replacement in conjunction with GH replacement is required to achieve the full anabolic effect in men with hypopituitarism. Copyright © 2017 Elsevier Ltd. All rights reserved.

Selective Estrogen Receptor Modulator (SERM)-like Activities of Diarylheptanoid, a Phytoestrogen from Curcuma comosa, in Breast Cancer Cells, Pre-osteoblast Cells, and Rat Uterine Tissues.

PubMed

Thongon, Natthakan; Boonmuen, Nittaya; Suksen, Kanoknetr; Wichit, Patsorn; Chairoungdua, Arthit; Tuchinda, Patoomratana; Suksamrarn, Apichart; Winuthayanon, Wipawee; Piyachaturawat, Pawinee

2017-05-03

Diarylheptanoids from Curcuma comosa, of the Zingiberaceae family, exhibit diverse estrogenic activities. In this study we investigated the estrogenic activity of a major hydroxyl diarylheptanoid, 7-(3,4 -dihydroxyphenyl)-5-hydroxy-1-phenyl-(1E)-1-heptene (compound 092) isolated from C. comosa. The compound elicited different transcriptional activities of estrogen agonist at low concentrations (0.1-1 μM) and antagonist at high concentrations (10-50 μM) using luciferase reporter gene assay in HEK-293T cells. In human breast cancer (MCF-7) cells, compound 092 showed an anti-estrogenic activity by down-regulating ERα-signaling and suppressing estrogen-responsive genes, whereas it attenuated the uterotrophic effect of estrogen in immature ovariectomized rats. Of note, compound 092 promoted mouse pre-osteoblastic (MC3T3-E1) cell differentiation and the related bone markers, indicating its positive osteogenic effect. Our findings highlight a new, nonsteroidal, estrogen agonist/antagonist of catechol diarylheptanoid from C. comosa, which is scientific evidence supporting its potential as a dietary supplement to prevent bone loss with low risk of breast and uterine cancers in postmenopausal women.

Elsevier Trophoblast Research Award lecture: Molecular mechanisms underlying estrogen functions in trophoblastic cells--focus on leptin expression.

PubMed

Gambino, Y P; Maymó, J L; Pérez Pérez, A; Calvo, J C; Sánchez-Margalet, V; Varone, C L

2012-02-01

The steroid hormone 17β-estradiol is an estrogen that influences multiple aspects of placental function and fetal development in humans. During early pregnancy it plays a role in the regulation of blastocyst implantation, trophoblast differentiation and invasiveness, remodeling of uterine arteries, immunology and trophoblast production of hormones such as leptin. Estradiol exerts some effects through the action of classical estrogen receptors ERα and ERβ, which act as ligand-activated transcription factors and regulate gene expression. In addition, estradiol can elicit rapid responses from membrane-associated receptors, like activation of protein-kinase pathways. Thus, the cellular effects of estradiol will depend on the specific receptors expressed and the integration of their signaling events. Leptin, the 16,000MW protein product of the obese gene, was originally considered an adipocyte-derived signaling molecule for the central control of metabolism. However, pleiotropic effects of leptin have been identified in reproduction and pregnancy. The leptin gene is expressed in placenta, where leptin promotes proliferation and survival of trophoblastic cells. Expression of leptin in placenta is highly regulated by key pregnancy molecules as hCG and estradiol. The aim of this paper is to review the molecular mechanisms underlying estrogen functions in trophoblastic cells; focusing on mechanisms involved in estradiol regulation of placental leptin expression. Copyright © 2012 Elsevier Ltd. All rights reserved.

Differential expression of microRNAs in omental adipose tissue from gestational diabetes mellitus subjects reveals miR-222 as a regulator of ERα expression in estrogen-induced insulin resistance.

PubMed

Shi, Zhonghua; Zhao, Chun; Guo, Xirong; Ding, Hongjuan; Cui, Yugui; Shen, Rong; Liu, Jiayin

2014-05-01

Omental adipose tissue plays a central role in insulin resistance in gestational diabetes mellitus (GDM), and the molecular mechanisms leading to GDM remains vague. Evidence demonstrates that maternal hormones, such as estradiol, contribute to insulin resistance in GDM. In this study we determined the differential expression patterns of microRNAs (miRNAs) in omental adipose tissues from GDM patients and pregnant women with normal glucose tolerance using AFFX miRNA expression chips. MiR-222, 1 of 17 identified differentially expressed miRNAs, was found to be significantly up-regulated in GDM by quantitative real-time PCR (P < .01), and its expression was closely related with serum estradiol level (P < .05). Furthermore, miR-222 expression was significantly increased in 3T3-L1 adipocytes with a high concentration of 17β-estradiol stimulation (P < .01), whereas the expressions of estrogen receptor (ER)-α protein and insulin-sensitive membrane transporter glucose transporter 4 (GLUT4) protein (P < .01) were markedly reduced. In addition, ERα was shown to be a direct target of miR-222 in 3T3-L1 adipocytes by using the luciferase assay. Finally, antisense oligonucleotides of miR-222 transfection was used to silence miR-222 in 3T3-L1 adipocytes. The results showed that the expressions of ERα and GLUT4, the insulin-stimulated translocation of GLUT4 from the cytoplasm to the cell membrane and glucose uptake in mature adipocytes were dramatically increased (P < .01). In conclusion, miR-222 is a potential regulator of ERα expression in estrogen-induced insulin resistance in GDM and might be a candidate biomarker and therapeutic target for GDM.

Induction of UO-44 gene expression by tamoxifen in the rat uterus and ovary.

PubMed

Huynh, H; Ng, C Y; Lim, K B; Ong, C K; Ong, C S; Tran, E; Tuyen Nguyen, T T; Chan, T W

2001-07-01

A complementary DNA, uterine-ovarian-specific gene 44 (UO-44), has been isolated from tamoxifen-induced rat uterine complementary DNA library using differential display techniques. UO-44 transcripts are found to be abundant in the uterus and ovary. UO-44 gene expression in the uterus is strictly regulated by estrogens, tamoxifen, and GH, whereas the pure antiestrogen ICI 182780 is inhibitory. Treatment of ovariectomized rats and hypophysectomized rats with tamoxifen and GH, respectively, resulted in up-regulation of UO-44 expression in a dose-dependent manner. In situ hybridization revealed that UO-44 gene expression was restricted to the luminal and glandular epithelial cells of the uterus and to granulosa cells of medium-size ovarian follicles. Transfection studies showed that UO-44 was a membrane-associated protein. Because estrogens, tamoxifen, and GH are stimulators of uterine luminal epithelial cell growth in vivo, UO-44 protein may serve as a mediator of the effect of these compounds in inducing epithelial proliferation and differentiation in these tissues.

Estrogen/ERR-α signaling axis is associated with fiber-type conversion of upper airway muscles in patients with obstructive sleep apnea hypopnea syndrome.

PubMed

Chen, H H; Lu, J; Guan, Y F; Li, S J; Hu, T T; Xie, Z S; Wang, F; Peng, X H; Liu, X; Xu, X; Zhao, F P; Yu, B L; Li, X P

2016-06-02

Estrogen is related with the low morbidity associated with obstructive sleep apnea hypopnea syndrome (OSAS) in women, but the underlying mechanisms remain largely unknown. In this study, we examined the relationship between OSAS and estrogen related receptor-α (ERR-α). We found that the expression levels of ERR-α and Myh7 were both downregulated in palatopharyngeal tissues from OSAS patients. In addition, we report that ERR-α is dynamically expressed during differentiation of C2C12 myoblasts. Knockdown of ERR-α via instant siRNA resulted in reduced expression of Myh7, but not Myh4. Furthermore, differentiation of C2C12 cells under 3% chronic intermittent hypoxia, a model resembling human OSAS, was impaired and accompanied by a obvious reduction in Myh7 expression levels. Moreover, activation of ERR-α with 17β-estradiol (E2) increased the expression of Myh7, whereas pretreatment with the ERR-α antagonist XCT790 reversed the E2-induced slow fiber-type switch. A rat ovariectomy model also demonstrated the switch to fast fiber type. Collectively, our findings suggest that ERR-α is involved in estrogen-mediated OSAS by regulating Myhc-slow expression. The present study illustrates an important role of the estrogen/ERR-α axis in the pathogenesis of OSAS, and may represent an attractive therapeutic target, especially in postmenopausal women.

Coexposure to phytoestrogens and bisphenol a mimics estrogenic effects in an additive manner.

PubMed

Katchy, Anne; Pinto, Caroline; Jonsson, Philip; Nguyen-Vu, Trang; Pandelova, Marchela; Riu, Anne; Schramm, Karl-Werner; Samarov, Daniel; Gustafsson, Jan-Åke; Bondesson, Maria; Williams, Cecilia

2014-03-01

Endocrine-disrupting chemicals (EDC) are abundant in our environment. A number of EDCs, including bisphenol A (BPA) can bind to the estrogen receptors (ER), ERα and ERβ, and may contribute to estrogen-linked diseases such as breast cancer. Early exposure is of particular concern; many EDCs cross the placenta and infants have measurable levels of, eg, BPA. In addition, infants are frequently fed soy-based formula (SF) that contains phytoestrogens. Effects of combined exposure to xeno- and phytoestrogens are poorly studied. Here, we extensively compared to what extent BPA, genistein, and an extract of infant SF mimic estrogen-induced gene transcription and cell proliferation. We investigated ligand-specific effects on ER activation in HeLa-ERα and ERβ reporter cells; on proliferation, genome-wide gene regulation and non-ER-mediated effects in MCF7 breast cancer cells; and how coexposure influenced these effects. The biological relevance was explored using enrichment analyses of differentially regulated genes and clustering with clinical breast cancer profiles. We demonstrate that coexposure to BPA and genistein, or SF, results in increased functional and transcriptional estrogenic effects. Using statistical modeling, we determine that BPA and phytoestrogens act in an additive manner. The proliferative and transcriptional effects of the tested compounds mimic those of 17β-estradiol, and are abolished by cotreatment with an ER antagonist. Gene expression profiles induced by each compound clustered with poor prognosis breast cancer, indicating that exposure may adversely affect breast cancer prognosis. This study accentuates that coexposure to BPA and soy-based phytoestrogens results in additive estrogenic effects, and may contribute to estrogen-linked diseases, including breast cancer.

Bone Marrow Oxytocin Mediates the Anabolic Action of Estrogen on the Skeleton*

PubMed Central

Colaianni, Graziana; Sun, Li; Di Benedetto, Adriana; Tamma, Roberto; Zhu, Ling-Ling; Cao, Jay; Grano, Maria; Yuen, Tony; Colucci, Sylvia; Cuscito, Concetta; Mancini, Lucia; Li, Jianhua; Nishimori, Katsuhiko; Bab, Itai; Lee, Heon-Jin; Iqbal, Jameel; Young, W. Scott; Rosen, Clifford; Zallone, Alberta; Zaidi, Mone

2012-01-01

Estrogen uses two mechanisms to exert its effect on the skeleton: it inhibits bone resorption by osteoclasts and, at higher doses, can stimulate bone formation. Although the antiresorptive action of estrogen arises from the inhibition of the MAPK JNK, the mechanism of its effect on the osteoblast remains unclear. Here, we report that the anabolic action of estrogen in mice occurs, at least in part, through oxytocin (OT) produced by osteoblasts in bone marrow. We show that the absence of OT receptors (OTRs) in OTR−/− osteoblasts or attenuation of OTR expression in silenced cells inhibits estrogen-induced osteoblast differentiation, transcription factor up-regulation, and/or OT production in vitro. In vivo, OTR−/− mice, known to have a bone formation defect, fail to display increases in trabecular bone volume, cortical thickness, and bone formation in response to estrogen. Furthermore, osteoblast-specific Col2.3-Cre+/OTRfl/fl mice, but not TRAP-Cre+/OTRfl/fl mice, mimic the OTR−/− phenotype and also fail to respond to estrogen. These data attribute the phenotype of OTR deficiency to an osteoblastic rather than an osteoclastic defect. Physiologically, feed-forward OT release in bone marrow by a rising estrogen concentration may facilitate rapid skeletal recovery during the latter phases of lactation. PMID:22761429

Stress-related disorders, pituitary adenylate cyclase-activating peptide (PACAP)ergic system, and sex differences.

PubMed

Ramikie, Teniel S; Ressler, Kerry J

2016-12-01

Trauma-related disorders, such as posttraumatic stress disorder (PTSD) are remarkably common and debilitating, and are often characterized by dysregulated threat responses. Across numerous epidemiological studies, females have been found to have an approximately twofold increased risk for PTSD and other stress-related disorders. Understanding the biological mechanisms of this differential risk is of critical importance. Recent data suggest that the pituitary adenylate cyclase-activating polypeptide (PACAP) pathway is a critical regulator of the stress response across species. Moreover, increasing evidence suggests that this pathway is regulated by both stress and estrogen modulation and may provide an important window into understanding mechanisms of sex differences in the stress response. We have recently shown that PACAP and its receptor (PAC1R) are critical mediators of abnormal processes after psychological trauma. Notably, in heavily traumatized human subjects, there appears to be a robust sex-specific association of PACAP blood levels and PAC1R gene variants with fear physiology, PTSD diagnosis, and symptoms, specifically in females. The sex-specific association occurs within a single-nucleotide polymorphism (rs2267735) that resides in a putative estrogen response element involved in PAC1R gene regulation. Complementing these human data, the PAC1R messenger RNA is induced with fear conditioning or estrogen replacement in rodent models. These data suggest that perturbations in the PACAP-PAC1R pathway are regulated by estrogen and are involved in abnormal fear responses underlying PTSD.

Bisphenol A and estradiol impede myoblast differentiation through down-regulating Akt signaling pathway.

PubMed

Go, Ga-Yeon; Lee, Sang-Jin; Jo, Ayoung; Lee, Jae-Rin; Kang, Jong-Sun; Yang, Mihi; Bae, Gyu-Un

2018-04-20

Bisphenol A (BPA), one of the most widespread endocrine disrupting chemicals, is known as an artificial estrogen, which interacts with estrogen receptor (ER). In this study, we investigated the effects of BPA and estradiol on myoblast differentiation and the underlying signaling mechanism. Exposure to BPA (0.01-1 μM) in mouse myoblast C2C12 cells attenuated myogenic differentiation via the reduced expression of muscle-specific genes, such as myosin heavy chain (MHC), MyoD, and Myogenin, without the alteration of cell proliferation and viability. BPA-exposed C2C12 myoblasts also showed a reduction of Akt phosphorylation ((37-61) %, p < 0.001), a key event for myogenesis. Similarly to BPA, estradiol (0.01-1 μM) reduced the expression of muscle-specific proteins and the formation of multinucleated myotubes, and attenuated the muscle differentiation-specific phosphorylation of Akt ((42-59) %, p < 0.001). We conclude that BPA and estradiol suppress myogenic differentiation through the inhibition of Akt signaling. Copyright © 2018 Elsevier B.V. All rights reserved.

Detection of 17 β-Estradiol in Environmental Samples and for Health Care Using a Single-Use, Cost-Effective Biosensor Based on Differential Pulse Voltammetry (DPV).

PubMed

Dai, Yifan; Liu, Chung Chiun

2017-03-29

Environmental estrogen pollution and estrogen effects on the female reproductive system are well recognized scientifically. Among the estrogens, 17 β-estradiol is a priority in environmental estrogen pollution, and it is also a major contributor to estrogen which regulates the female reproductive system. 17 β-estradiol is carcinogenic and has a tumor promotion effect relating to breast cancer, lung cancer and others. It also affects psychological well-being such as depression, fatigue and others. Thus, a simple method of detecting 17 β-estradiol will be important for both environmental estrogen pollution and health care. This study demonstrates a single-use, cost-effective 17 β-estradiol biosensor system which can be used for both environmental and health care applications. The bio-recognition mechanism is based on the influence of the redox couple, K₃Fe(CN)₆/K₄Fe(CN)₆ by the interaction between 17 β-estradiol antigen and its α-receptor (ER-α; α-estrogen antibody). The transduction mechanism is an electrochemical analytical technique, differential pulse voltammetry (DPV). The levels of 17 β-estradiol antigen studied were between 2.25 pg/mL and 2250 pg/mL; Phosphate buffered saline (PBS), tap water from the Cleveland regional water district, and simulated urine were used as the test media covering the potential application areas for 17 β-estradiol detection. An interference study by testosterone, which has a similar chemical structure and molecular weight as those of 17 β-estradiol, was carried out, and this 17 β-estradiol biosensor showed excellent specificity without any interference by similar chemicals.

Differential Regulation of Aromatase Isoforms and Tissue Responses to Environmental Chemicals in Fish

EPA Science Inventory

As in mammals, aromatase plays a basic role in fish reproduction. Unlike most mammals, with only one form of aromatase, fish have two distinct forms. One isoform, P450aromA, predominates in ovaries. Ovarian aromatase activity controls circulating levels of estrogens and is critic...

A New Regulator of Osteoclastogenesis: Estrogen Response Element–Binding Protein in Bone

PubMed Central

Chen, Hong; Gilbert, Linda C; Lu, X; Liu, Zhaofan; You, Shaojin; Weitzmann, M Neale; Nanes, Mark S; Adams, John

2012-01-01

The heterogeneous nuclear ribonucleoprotein (hnRNP)–like estrogen response element–binding protein (ERE-BP) competes with estrogen receptor α (ERα) for occupancy of estrogen response elements (EREs). Here we report that ERE-BP potently stimulates osteoclastogenesis. ERE-BP mRNA and protein were found to be expressed ubiquitously in bone. Overexpression of ERE-BP in cultured osteoblasts stimulated expression of the receptor activator of NF-κB ligand (RANKL) and decreased osteoprotegerin (OPG). The effect of ERE-BP on RANKL was shown to be transcriptional in transient transfection assay and competed with via the ER. Constitutive expression of ERE-BP increased the sensitivity of cells toward 1,25-dihydroxyvitamin D3 stimulation of RANKL expression. In contrast, knockdown of ERE-BP in stromal ST-2 cells decreased basal RANKL promoter activity. Cocultures of ERE-BP lentivirus–transduced ST-2 cells with spleen monocytes induced formation of multinucleated osteoclasts (OCs) characterized by tartrate-resistant acid phosphatase, calcitonin receptors, and functional calcium resorption from bone slices. Although ERα competed with ERE-BP for an ERE in a dose-dependent manner, ERE-BP was an independent and potent regulator of RANKL and osteoclastogenesis. In preosteoclastic RAW cells, overexpression of ERE-BP increased RANK, upregulated NF-κB signaling, and enhanced differentiation toward a mature OC phenotype independent of RANKL. These results identify ERE-BP as a potent modulator of osteoclastogenesis. We hypothesize that ERE-BP may play a critical role in the regulation of bone homeostasis as a modulator of estrogen sensitivity as well as by direct action on the transcription of critical osteoclastogenic genes. PMID:21773989

Uterine Deletion of Gp130 or Stat3 Shows Implantation Failure with Increased Estrogenic Responses

PubMed Central

Sun, Xiaofei; Bartos, Amanda; Whitsett, Jeffrey A.

2013-01-01

Leukemia inhibitory factor (LIF), a downstream target of estrogen, is essential for implantation in mice. LIF function is thought to be mediated by its binding to LIF receptor (LIFR) and recruitment of coreceptor GP130 (glycoprotein 130), and this receptor complex then activates signal transducer and activator of transcription (STAT)1/3. However, the importance of LIFR and GP130 acting via STAT3 in implantation remains uncertain, because constitutive inactivation of Lifr, Gp130, or Stat3 shows embryonic lethality in mice. To address this issue, we generated mice with conditional deletion of uterine Gp130 or Stat3 and show that both GP130 and STAT3 are critical for uterine receptivity and implantation. Implantation failure in these deleted mice is associated with higher uterine estrogenic responses prior to the time of implantation. These heightened estrogenic responses are not due to changes in ovarian hormone levels or expression of their nuclear receptors. In the deleted mice, estrogen-responsive gene, Lactoferrin (Ltf), and Mucin 1 protein, were up-regulated in the uterus. In addition, progesterone-responsive genes, Hoxa10 and Indian hedgehog (Ihh), were markedly down-regulated in STAT3-inactivated uteri. These changes in uteri of deleted mice were reflected by the failure of differentiation of the luminal epithelium, which is essential for blastocyst attachment. PMID:23885093

Function and regulation of MTA1 and MTA3 in malignancies of the female reproductive system.

PubMed

Brüning, Ansgar; Blankenstein, Thomas; Jückstock, Julia; Mylonas, Ioannis

2014-12-01

The family of metastasis-associated (MTA) genes is a small group of transcriptional co-regulators which are involved in various physiological functions, ranging from lymphopoietic cell differentiation to the development and maintenance of epithelial cell adhesions. By recruiting histone-modifying enzymes to specific promoter sequences, MTA proteins can function both as transcriptional repressors and activators of a number of cancer-relevant proteins, including Snail, E-cadherin, signal transducer and activator of transcriptions (STATs), and the estrogen receptor. Their involvement in the epithelial-mesenchymal transition process and regulatory interactions with estrogen receptor activity has made MTA proteins highly interesting research candidates, especially in the field of hormone-sensitive breast cancer and malignancies of the female reproductive tract. This review focuses on the current knowledge about the function and regulation of MTA1 and MTA3 proteins in gynecological cancer, including ovarian, endometrial, and cervical tumors.

The estrogen-related receptors and the adipocyte.

PubMed

Carnesecchi, Julie; Vanacker, Jean-Marc

2013-08-01

The estrogen-related receptors (ERRα, β, and γ) are orphan members of the nuclear receptor superfamily. ERRα and γ are highly expressed in tissues displaying elevated energy demands and are involved in several aspects of energetic metabolism, which they regulate mostly in association with members of the PGC-1 coactivator family. These activities have mostly been documented in the liver, heart, or skeletal muscle. ERRα and γ are also highly expressed in adipocytes. Their precise roles in this cell type are less documented, although published data indicate that they contribute to cell differentiation as well as functionality. This review describes these activities.

Estrogens and development

DOE Office of Scientific and Technical Information (OSTI.GOV)

McLachlan, J.A.; Newbold, R.R.

1987-11-01

The normal development of the genital organs of mammals, including humans, is under hormonal control. A role for the female sex hormone estrogen in this process is still unclear. However, exposure of experimental animals or humans to the potent exogenous estrogen, diethylstilbestrol (DES), results in persistent differentiation effects. Since many chemicals in the environment are weakly estrogenic, the possibility of hormonally altered differentiation must be considered.

The effect of tamoxifen and raloxifene on estrogen metabolism and endometrial cancer risk.

PubMed

Williams-Brown, Marian Y; Salih, Sana M; Xu, Xia; Veenstra, Timothy D; Saeed, Muhammad; Theiler, Shaleen K; Diaz-Arrastia, Concepcion R; Salama, Salama A

2011-09-01

Selective estrogen receptor modulators (SERMs) demonstrate differential endometrial cancer (EC) risk. While tamoxifen (TAM) use increases the risk of endometrial hyperplasia and malignancy, raloxifene (RAL) has neutral effects on the uterus. How TAM increases the risk of EC and why TAM and RAL differentially modulate the risk for EC, however, remain elusive. Here, we tested the hypothesis that TAM increases the risk for EC, at least in part, by enhancing the local estrogen biosynthesis and directing estrogen metabolism towards the formation of genotoxic and hormonally active estrogen metabolites. In addition, the differential effects of TAM and RAL in EC risk are attributed to their differential effect on estrogen metabolism/metabolites. The endometrial cancer cell line (Ishikawa cells) and the nonmalignant immortalized human endometrial glandular cell line (EM1) were used for the study. The profile of estrogen/estrogen metabolites (EM), depurinating estrogen-DNA adducts, and the expression of estrogen-metabolizing enzymes in cells treated with 17β-estradiol (E2) alone or in combination with TAM or RAL were investigated using high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS(2)), ultraperformance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS), and Western blot analysis, respectively. TAM significantly increased the total EM and enhanced the formation of hormonally active and carcinogenic estrogen metabolites, 4-hydroxestrone (4-OHE1) and 16α-hydroxyestrone, with concomitant reduction in the formation of antiestrogenic and anticarcinogenic 2-hydroxyestradiol and 2-methoxyestradiol. Furthermore, TAM increased the formation of depurinating estrogen-DNA adducts 4-OHE1 [2]-1-N7Guanine and 4-OHE1 [2]-1-N3 Adenine. TAM-induced alteration in EM and depurinating DNA adduct formation is associated with altered expression of estrogen metabolizing enzymes CYP1A1, CYP1B1, COMT, NQO1, and SF-1 as revealed by Western blot analysis. In contrast to TAM, RAL has minimal effect on EM, estrogen-DNA adduct formation, or estrogen-metabolizing enzymes expression. These data show that TAM perturbs the balance of estrogen-metabolizing enzymes and alters the disposition of estrogen metabolites, which can explain, at least in part, the mechanism for TAM-induced EC. These results also implicate the differential effect of TAM and RAL on estrogen metabolism/metabolites as a potential mechanism for their disparate effects on the endometrium. Copyright © 2011 Elsevier Ltd. All rights reserved.

Progesterone receptor isoforms, agonists and antagonists differentially reprogram estrogen signaling

PubMed Central

Singhal, Hari; Greene, Marianne E.; Zarnke, Allison L.; Laine, Muriel; Al Abosy, Rose; Chang, Ya-Fang; Dembo, Anna G.; Schoenfelt, Kelly; Vadhi, Raga; Qiu, Xintao; Rao, Prakash; Santhamma, Bindu; Nair, Hareesh B.; Nickisch, Klaus J.; Long, Henry W.; Becker, Lev; Brown, Myles; Greene, Geoffrey L.

2018-01-01

Major roadblocks to developing effective progesterone receptor (PR)-targeted therapies in breast cancer include the lack of highly-specific PR modulators, a poor understanding of the pro- or anti-tumorigenic networks for PR isoforms and ligands, and an incomplete understanding of the cross talk between PR and estrogen receptor (ER) signaling. Through genomic analyses of xenografts treated with various clinically-relevant ER and PR-targeting drugs, we describe how the activation or inhibition of PR differentially reprograms estrogen signaling, resulting in the segregation of transcriptomes into separate PR agonist and antagonist-mediated groups. These findings address an ongoing controversy regarding the clinical utility of PR agonists and antagonists, alone or in combination with tamoxifen, for breast cancer management. Additionally, the two PR isoforms PRA and PRB, bind distinct but overlapping genomic sites and interact with different sets of co-regulators to differentially modulate estrogen signaling to be either pro- or anti-tumorigenic. Of the two isoforms, PRA inhibited gene expression and ER chromatin binding significantly more than PRB. Differential gene expression was observed in PRA and PRB-rich patient tumors and PRA-rich gene signatures had poorer survival outcomes. In support of antiprogestin responsiveness of PRA-rich tumors, gene signatures associated with PR antagonists, but not PR agonists, predicted better survival outcomes. The better patient survival associated with PR antagonists versus PR agonists treatments was further reflected in the higher in vivo anti-tumor activity of therapies that combine tamoxifen with PR antagonists and modulators. This study suggests that distinguishing common effects observed due to concomitant interaction of another receptor with its ligand (agonist or antagonist), from unique isoform and ligand-specific effects will inform the development of biomarkers for patient selection and translation of PR-targeted therapies to the clinic. PMID:29435103

Bone marrow adipocytes: a neglected target tissue for growth hormone.

PubMed

Gevers, Evelien F; Loveridge, Nigel; Robinson, Iain C A F

2002-10-01

Bone marrow (BM) contains numerous adipocytes. These share a common precursor with osteoblasts and chondrocytes, but their function is unknown. It is unclear what regulates the differentiation of these three different cell types, though their subsequent metabolic activity is under hormonal regulation. GH and estrogen stimulate bone growth and mineralization, by direct effects on chondrocytes and osteoblasts. GH also stimulates lipolysis in subcutaneous and visceral adipocytes. However, adipocytes in BM have largely been ignored as potential targets for GH or estrogen action. We have addressed this by measuring BM adipocyte number, perimeter and area as well as bone area and osteoblast activity in GH-deficient dwarf (dw/dw), normal, or ovariectomized (Ovx) rats, with or without GH, IGF-1, PTH, or estrogen treatment or high fat feeding. Marrow adipocyte numbers were increased 5-fold (P < 0.001) in dw/dw rats, and cell size was also increased by 20%. These values returned toward normal in dw/dw rats given GH but not when given IGF-1. Cancellous bone area and osteoblast number were significantly (P < 0.005) lower in dw/dw rats, though alkaline phosphatase (ALP) activity in individual osteoblasts was unchanged. GH treatment increased % osteoblast covered bone surface without affecting individual cell ALP activity. Ovariectomy in normal or dw/dw rats had no affect on marrow adipocyte number nor size, although estrogen treatment in ovariectomized (Ovx) normal rats did increase adipocyte number. Ovx decreased tibial cancellous bone area in normal rats (64%; P < 0.05) and decreased osteoblast ALP-activity (P < 0.01) but did not affect the percentage of osteoblast-covered bone surface. Estrogen replacement reversed these changes. While treatment with PTH by continuous sc infusion decreased cancellous bone (P < 0.05) and high fat feeding increased the size of BM adipocytes (P < 0.01), they did not affect BM adipocyte number. These results suggest that GH has a specific action on BM adipocytes that is not simply due to altered bone or fat metabolism. We conclude that the marrow adipocyte lineage is an important and specific target for GH action. The inverse relationship between adipocyte number and osteoblast covered bone surface, together with the well-known effects of GH on epiphysial chondrocytes leads us to propose that GH plays two important roles on cells of all three lineages. During differentiation, it regulates the numbers of each cell type that are maintained from the common precursor lineage. Subsequently it has cell-specific effects on the metabolic activities of the differentiated cells. In the case of marrow adipocytes, GH-dependent lipolysis could provide an important hormonally regulated local high energy source in bone.

ERβ regulates miR-21 expression and inhibits invasion and metastasis in cancer cells

NASA Astrophysics Data System (ADS)

Tian, Junmei; Tu, Zhenzhen; Chen, Wei R.; Gu, Yueqing

2012-03-01

In human, estrogens play important roles in many physiological processes, and is also found to be connected with numerous cancers. In these diseases, estrogen mediates its effects through the estrogen receptor (ER), which serves as the basis for many current clinical diagnosis. Two forms of the estrogen receptor have been identified, ERα and ERβ, and show different and specific functions. The two estrogen receptors belong to a family of ligand-regulated transcription factors. Estrogen via ERα stimulates proliferation in the breast, uterus, and developing prostate, while estrogen via ERβ inhibits proliferation and promotes differentiation in the prostate, mammary gland, colon, lung, and bone marrow stem cells. MicroRNAs (miRs) are small non-coding RNA molecules that occur naturally and downregulate protein expression by translational blockade of the target mRNA or by promoting mRNA decay. MiR-21 is one of the most studied miRNAs in cancers. MiR-21 is overexpressed in the most solid tumors, promoting progression and metastasis. The miR-21 gene is located on the chromosome 17, in the 10th intron of a protein-coding gene, TMEM49. While, the function of TMEM49 is currently unknown. Our experiment is designed to identity the relationship between miR-21 and ERβ in cancer progression. The human cancer cells were transfected with ERβ. Real-time PCR analysis showed that the expression level of miR-21 was significantly inhibited down by ERβ treatment. As MTT assay showed the tumor cell survival rate was also inhibited significantly. Go/Gl phase cell cycle arrest was founded and tumor cell apoptosis was induced in ERβ group.

Coexposure to Phytoestrogens and Bisphenol A Mimics Estrogenic Effects in an Additive Manner

PubMed Central

Katchy, Anne; Pinto, Caroline; Williams, Cecilia

2014-01-01

Endocrine-disrupting chemicals (EDC) are abundant in our environment. A number of EDCs, including bisphenol A (BPA) can bind to the estrogen receptors (ER), ERα and ERβ, and may contribute to estrogen-linked diseases such as breast cancer. Early exposure is of particular concern; many EDCs cross the placenta and infants have measurable levels of, eg, BPA. In addition, infants are frequently fed soy-based formula (SF) that contains phytoestrogens. Effects of combined exposure to xeno- and phytoestrogens are poorly studied. Here, we extensively compared to what extent BPA, genistein, and an extract of infant SF mimic estrogen-induced gene transcription and cell proliferation. We investigated ligand-specific effects on ER activation in HeLa-ERα and ERβ reporter cells; on proliferation, genome-wide gene regulation and non-ER–mediated effects in MCF7 breast cancer cells; and how coexposure influenced these effects. The biological relevance was explored using enrichment analyses of differentially regulated genes and clustering with clinical breast cancer profiles. We demonstrate that coexposure to BPA and genistein, or SF, results in increased functional and transcriptional estrogenic effects. Using statistical modeling, we determine that BPA and phytoestrogens act in an additive manner. The proliferative and transcriptional effects of the tested compounds mimic those of 17β-estradiol, and are abolished by cotreatment with an ER antagonist. Gene expression profiles induced by each compound clustered with poor prognosis breast cancer, indicating that exposure may adversely affect breast cancer prognosis. This study accentuates that coexposure to BPA and soy-based phytoestrogens results in additive estrogenic effects, and may contribute to estrogen-linked diseases, including breast cancer. PMID:24284790

RNA-Seq analysis of transcriptome responses in Atlantic cod (Gadus morhua) precision-cut liver slices exposed to benzo[a]pyrene and 17α-ethynylestradiol.

PubMed

Yadetie, Fekadu; Zhang, Xiaokang; Hanna, Eileen Marie; Aranguren-Abadía, Libe; Eide, Marta; Blaser, Nello; Brun, Morten; Jonassen, Inge; Goksøyr, Anders; Karlsen, Odd André

2018-06-07

Polycyclic aromatic hydrocarbons such as benzo[a]pyrene (BaP) that activate the aryl hydrocarbon receptor (Ahr) pathway, and endocrine disruptors acting through the estrogen receptor pathway are among environmental pollutants of major concern. In this work, we exposed Atlantic cod (Gadus morhua) precision-cut liver slices (PCLS) to BaP (10 nM and 1000 nM), ethynylestradiol (EE2) (10 nM and 1000 nM), and equimolar mixtures of BaP and EE2 (10 nM and 1000 nM) for 48 h, and performed RNA-Seq based transcriptome mapping followed by systematic bioinformatics analyses. Our gene expression analysis showed that several genes were differentially expressed in response to BaP and EE2 treatments in PCLS. Strong up-regulation of genes coding for the cytochrome P450 1a (Cyp1a) enzyme and the Ahr repressor (Ahrrb) was observed in BaP treated PCLS. EE2 treatment of liver slices strongly up-regulated genes coding for precursors of vitellogenin (Vtg) and eggshell zona pellucida (Zp) proteins. As expected, pathway enrichment and network analysis showed that the Ahr and estrogen receptor pathways are among the top affected by BaP and EE2 treatments, respectively. Interestingly, two genes coding for fibroblast growth factor 3 (Fgf3) and fibroblast growth factor 4 (Fgf4) were up-regulated by EE2 in this study. To our knowledge, the fgf3 and fgf4 genes have not previously been described in relation to estrogen signaling in fish liver, and these results suggest the modulation of the FGF signaling pathway by estrogens in fish. The signature expression profiles of top differentially expressed genes in response to the single compound (BaP or EE2) treatment were generally maintained in the expression responses to the equimolar binary mixtures. However, in the mixture-treated groups, BaP appeared to have anti-estrogenic effects as observed by lower number of differentially expressed putative EE2 responsive genes. Our in-depth quantitative analysis of changes in liver transcriptome in response to BaP and EE2, using PCLS tissue culture provides further mechanistic insights into effects of the compounds. Moreover, the analyses demonstrate the usefulness of PCLS in cod for omics experiments. Copyright © 2018 Elsevier B.V. All rights reserved.

Estrogenic modulation of inflammation-related genes in male rats following volume overload

PubMed Central

McLarty, Jennifer L.; Meléndez, Giselle C.; Levick, Scott P.; Bennett, Shanté; Sabo-Attwood, Tara; Brower, Gregory L.

2012-01-01

Our laboratory has previously reported significant increases of the proinflammatory cytokine TNF-α in male hearts secondary to sustained volume overload. These elevated levels of TNF-α are accompanied by left ventricular (LV) dilatation and cardiac dysfunction. In contrast, estrogen has been shown to protect against this adverse cardiac remodeling in both female and male rats. The purpose of this study was to determine whether estrogen has an effect on inflammation-related genes that contribute to this estrogen-mediated cardioprotection. Myocardial volume overload was induced by aortocaval fistula in 8 wk old male Sprague-Dawley rats (n = 30), and genes of interest were identified using an inflammatory PCR array in Sham, Fistula, and Fistula + Estrogen-treated (0.02 mg/kg per day beginning 2 wk prior to fistula) groups. A total of 55 inflammatory genes were modified (≥2-fold change) at 3 days postfistula. The number of inflammatory gene was reduced to 21 genes by estrogen treatment, whereas 13 genes were comparably modulated in both fistula groups. The most notable were TNF-α, which was downregulated by estrogen, and the TNF-α receptors, which were differentially regulated by estrogen. Specific genes related to arachidonic acid metabolism were downregulated by estrogen, including cyclooxygenase-1 and -2. Finally, gene expression for the β1-integrin cell adhesion subunit was significantly upregulated in the LV of estrogen-treated animals. Protein levels reflected the changes observed at the gene level. These data suggest that estrogen provides its cardioprotective effects, at least in part, via genomic modulation of numerous inflammation-related genes. PMID:22274565

Regulation of ERRα Gene Expression by Estrogen Receptor Agonists and Antagonists in SKBR3 Breast Cancer Cells: Differential Molecular Mechanisms Mediated by G Protein-Coupled Receptor GPR30/GPER-1

PubMed Central

Li, Yin; Birnbaumer, Lutz; Teng, Christina T.

2010-01-01

In selected tissues and cell lines, 17β-estradiol (E2) regulates the expression of estrogen-related receptor α (ERRα), a member of the orphan nuclear receptor family. This effect is thought to be mediated by the estrogen receptor α (ERα). However in the ERα- and ERβ-negative SKBR3 breast cancer cell line, physiological levels of E2 also stimulate ERRα expression. Here, we explored the molecular mechanism that mediates estrogen action in ER-negative breast cancer cells. We observed that E2, the ERα agonist, as well as the ERα antagonists ICI 182,780 and tamoxifen (TAM), a selective ER modulator, stimulate the transcriptional activity of the ERRα gene and increase the production of ERRα protein in SKBR3 cells. Moreover, the ERRα downstream target genes expression and cellular proliferation are also increased. We show further that the G protein-coupled receptor GPR30/GPER-1 (GPER-1) mediates these effects. The GPER-1 specific ligand G-1 mimics the actions of E2, ICI 182,780, and TAM on ERRα expression, and changing the levels of GPER-1 mRNA by overexpression or small interfering RNA knockdown affected the expression of ERRα accordingly. Utilizing inhibitors, we delineate a different downstream pathway for ER agonist and ER antagonist-triggered signaling through GPER-1. We also find differential histone acetylation and transcription factor recruitment at distinct nucleosomes of the ERRα promoter, depending on whether the cells are activated with E2 or with ER antagonists. These findings provide insight into the molecular mechanisms of GPER-1/ERRα-mediated signaling and may be relevant to what happens in breast cancer cells escaping inhibitory control by TAM. PMID:20211987

Melanocortin 4 receptor is not required for estrogenic regulations on energy homeostasis and reproduction.

PubMed

Xu, Pingwen; Zhu, Liangru; Saito, Kenji; Yang, Yongjie; Wang, Chunmei; He, Yanlin; Yan, Xiaofeng; Hyseni, Ilirjana; Tong, Qingchun; Xu, Yong

2017-05-01

Brain estrogen receptor-α (ERα) is essential for estrogenic regulation of energy homeostasis and reproduction. We previously showed that ERα expressed by pro-opiomelanocortin (POMC) neurons mediates estrogen's effects on food intake, body weight, negative regulation of hypothalamic-pituitary-gonadal axis (HPG axis) and fertility. We report here that global deletion of a key downstream receptor for POMC peptide, the melanocortin 4 receptor (MC4R), did not affect normal negative feedback regulation of estrogen on the HPG axis, estrous cyclicity and female fertility. Furthermore, loss of the MC4R did not influence estrogenic regulation on food intake and body weight. These results indicate that the MC4R is not required for estrogen's effects on metabolic and reproductive functions. Copyright © 2016 Elsevier Inc. All rights reserved.

Steroid signaling system responds differently to temperature and hormone manipulation in the red-eared slider turtle (Trachemys scripta elegans), a reptile with temperature-dependent sex determination.

PubMed

Ramsey, M; Crews, D

2007-01-01

Many reptiles, including the red-eared slider turtle (Trachemys scripta elegans), exhibit temperature-dependent sex determination (TSD). Temperature determines gonadal sex during the middle of embryogenesis, or the temperature-sensitive period (TSP), when gonadal sex is labile to both temperature and hormones--particularly estrogen. The biological actions of steroid hormones are mediated by their receptors as defined here as the classic transcriptional regulation of target genes. To elucidate estrogen action during sex determination, we examined estrogen receptor alpha (Esr1, hereafter referred to as ERalpha), estrogen receptor beta (Esr2, hereafter referred to as ERbeta), and androgen receptor (Ar, hereafter referred to as AR) expression in slider turtle gonads before, during and after the TSP, as well as following sex reversal via temperature or steroid hormone manipulation. ERalpha and AR levels spike at the female-producing temperature while ovarian sex is determined, but none of the receptors exhibited sexually dimorphic localization within the gonad prior to morphological differentiation. All three receptors respond differentially to sex-reversing treatments. When shifted to female-producing temperatures, embryos maintain ERalpha and AR expression while ERbeta is reduced. When shifted to male-producing temperatures, medullary expression of all three receptors is reduced. Feminization via estradiol (E(2)) treatment at a male-producing temperature profoundly changed the expression patterns for all three receptors. ERalpha and ERbeta redirected to the cortex in E(2)-created ovaries, while AR medullary expression was transiently reduced. Although warmer incubation temperature and estrogen result in the same endpoint (ovarian development), our results indicate different steroid signaling patterns between temperature- and estrogen-induced feminization. 2007 S. Karger AG, Basel

Estrogen receptor β (ERβ1) transactivation is differentially modulated by the transcriptional coregulator Tip60 in a cis-acting element-dependent manner.

PubMed

Lee, Ming-Tsung; Leung, Yuet-Kin; Chung, Irving; Tarapore, Pheruza; Ho, Shuk-Mei

2013-08-30

Estrogen receptor (ER) β1 and ERα have overlapping and distinct functions despite their common use of estradiol as the physiological ligand. These attributes are explained in part by their differential utilization of coregulators and ligands. Although Tip60 has been shown to interact with both receptors, its regulatory role in ERβ1 transactivation has not been defined. In this study, we found that Tip60 enhances transactivation of ERβ1 at the AP-1 site but suppresses its transcriptional activity at the estrogen-response element (ERE) site in an estradiol-independent manner. However, different estrogenic compounds can modify the Tip60 action. The corepressor activity of Tip60 at the ERE site is abolished by diarylpropionitrile, genistein, equol, and bisphenol A, whereas its coactivation at the AP-1 site is augmented by fulvestrant (ICI 182,780). GRIP1 is an important tethering mediator for ERs at the AP-1 site. We found that coexpression of GRIP1 synergizes the action of Tip60. Although Tip60 is a known acetyltransferase, it is unable to acetylate ERβ1, and its coregulatory functions are independent of its acetylation activity. In addition, we showed the co-occupancy of ERβ1 and Tip60 at ERE and AP-1 sites of ERβ1 target genes. Tip60 differentially regulates the endogenous expression of the target genes by modulating the binding of ERβ1 to the cis-regulatory regions. Thus, we have identified Tip60 as the first dual-function coregulator of ERβ1.

Estrogen Receptor β (ERβ1) Transactivation Is Differentially Modulated by the Transcriptional Coregulator Tip60 in a cis-Acting Element-dependent Manner*

PubMed Central

Lee, Ming-Tsung; Leung, Yuet-Kin; Chung, Irving; Tarapore, Pheruza; Ho, Shuk-Mei

2013-01-01

Estrogen receptor (ER) β1 and ERα have overlapping and distinct functions despite their common use of estradiol as the physiological ligand. These attributes are explained in part by their differential utilization of coregulators and ligands. Although Tip60 has been shown to interact with both receptors, its regulatory role in ERβ1 transactivation has not been defined. In this study, we found that Tip60 enhances transactivation of ERβ1 at the AP-1 site but suppresses its transcriptional activity at the estrogen-response element (ERE) site in an estradiol-independent manner. However, different estrogenic compounds can modify the Tip60 action. The corepressor activity of Tip60 at the ERE site is abolished by diarylpropionitrile, genistein, equol, and bisphenol A, whereas its coactivation at the AP-1 site is augmented by fulvestrant (ICI 182,780). GRIP1 is an important tethering mediator for ERs at the AP-1 site. We found that coexpression of GRIP1 synergizes the action of Tip60. Although Tip60 is a known acetyltransferase, it is unable to acetylate ERβ1, and its coregulatory functions are independent of its acetylation activity. In addition, we showed the co-occupancy of ERβ1 and Tip60 at ERE and AP-1 sites of ERβ1 target genes. Tip60 differentially regulates the endogenous expression of the target genes by modulating the binding of ERβ1 to the cis-regulatory regions. Thus, we have identified Tip60 as the first dual-function coregulator of ERβ1. PMID:23857583

Identification of key genes associated with the effect of estrogen on ovarian cancer using microarray analysis.

PubMed

Zhang, Shi-tao; Zuo, Chao; Li, Wan-nan; Fu, Xue-qi; Xing, Shu; Zhang, Xiao-ping

2016-02-01

To identify key genes related to the effect of estrogen on ovarian cancer. Microarray data (GSE22600) were downloaded from Gene Expression Omnibus. Eight estrogen and seven placebo treatment samples were obtained using a 2 × 2 factorial designs, which contained 2 cell lines (PEO4 and 2008) and 2 treatments (estrogen and placebo). Differentially expressed genes were identified by Bayesian methods, and the genes with P < 0.05 and |log2FC (fold change)| ≥0.5 were chosen as cut-off criterion. Differentially co-expressed genes (DCGs) and differentially regulated genes (DRGs) were, respectively, identified by DCe function and DRsort function in DCGL package. Topological structure analysis was performed on the important transcriptional factors (TFs) and genes in transcriptional regulatory network using tYNA. Functional enrichment analysis was, respectively, performed for DEGs and the important genes using Gene Ontology and KEGG databases. In total, 465 DEGs were identified. Functional enrichment analysis of DEGs indicated that ACVR2B, LTBP1, BMP7 and MYC involved in TGF-beta signaling pathway. The 2285 DCG pairs and 357 DRGs were identified. Topological structure analysis showed that 52 important TFs and 65 important genes were identified. Functional enrichment analysis of the important genes showed that TP53 and MLH1 participated in DNA damage response and the genes (ACVR2B, LTBP1, BMP7 and MYC) involved in TGF-beta signaling pathway. TP53, MLH1, ACVR2B, LTBP1 and BMP7 might participate in the pathogenesis of ovarian cancer.

Differential hydrogen/deuterium exchange mass spectrometry analysis of protein–ligand interactions

PubMed Central

Chalmers, Michael J; Busby, Scott A; Pascal, Bruce D; West, Graham M; Griffin, Patrick R

2011-01-01

Functional regulation of ligand-activated receptors is driven by alterations in the conformational dynamics of the protein upon ligand binding. Differential hydrogen/deuterium exchange (HDX) coupled with mass spectrometry has emerged as a rapid and sensitive approach for characterization of perturbations in conformational dynamics of proteins following ligand binding. While this technique is sensitive to detecting ligand interactions and alterations in receptor dynamics, it also can provide important mechanistic insights into ligand regulation. For example, HDX has been used to determine a novel mechanism of ligand activation of the nuclear receptor peroxisome proliferator activated receptor-γ, perform detailed analyses of binding modes of ligands within the ligand-binding pocket of two estrogen receptor isoforms, providing insight into selectivity, and helped classify different types of estrogen receptor-α ligands by correlating their pharmacology with the way they interact with the receptor based solely on hierarchical clustering of receptor HDX signatures. Beyond small-molecule–receptor interactions, this technique has also been applied to study protein–protein complexes, such as mapping antibody–antigen interactions. In this article, we summarize the current state of the differential HDX approaches and the future outlook. We summarize how HDX analysis of protein–ligand interactions has had an impact on biology and drug discovery. PMID:21329427

Melanocortin 4 receptor is not required for estrogenic regulations on energy homeostasis and reproduction

USDA-ARS?s Scientific Manuscript database

Brain estrogen receptor-a (ERa) is essential for estrogenic regulation of energy homeostasis and reproduction. We previously showed that ERa expressed by pro-opiomelanocortin (POMC) neurons mediates estrogen's effects on food intake, body weight, negative regulation of hypothalamic–pituitary–gonadal...

Roles of Estrogen Receptor-α and the Coactivator MED1 During Human Endometrial Decidualization

PubMed Central

Kaya Okur, Hatice S.; Das, Amrita; Taylor, Robert N.; Bagchi, Indrani C.

2016-01-01

The steroid hormones 17β-estradiol and progesterone are critical regulators of endometrial stromal cell differentiation, known as decidualization, which is a prerequisite for successful establishment of pregnancy. The present study using primary human endometrial stromal cells (HESCs) addressed the role of estrogen receptor-α (ESR1) in decidualization. Knockdown of ESR1 transcripts by RNA interference led to a marked reduction in decidualization of HESCs. Gene expression profiling at an early stage of decidualization indicated that ESR1 negatively regulates several cell cycle regulatory factors, thereby suppressing the proliferation of HESCs as these cells enter the differentiation program. ESR1 also controls the expression of WNT4, FOXO1, and progesterone receptor (PGR), well-known mediators of decidualization. Whereas ESR1 knockdown strongly inhibited the expression of FOXO1 and WNT4 transcripts within 24 hours of the initiation of decidualization, PGR expression remained unaffected at this early time point. Our study also revealed a major role of cAMP signaling in influencing the function of ESR1 during decidualization. Using a proteomic approach, we discovered that the cAMP-dependent protein kinase A (PKA) phosphorylates Mediator 1 (MED1), a subunit of the mediator coactivator complex, during HESC differentiation. Using immunoprecipitation, we demonstrated that PKA-phosphorylated MED1 interacts with ESR1. The PKA-dependent phosphorylation of MED1 was also correlated with its enhanced recruitment to estrogen-responsive elements in the WNT4 gene. Knockdown of MED1 transcripts impaired the expression of ESR1-induced WNT4 and FOXO1 transcripts and blocked decidualization. Based on these findings, we conclude that modulation of ESR1-MED1 interactions by cAMP signaling plays a critical role in human decidualization. PMID:26849466

Endometrial Cancer-Associated FGF18 Expression Is Reduced by Bazedoxifene in Human Endometrial Stromal Cells In Vitro and in Murine Endometrium

PubMed Central

Flannery, Clare A.; Fleming, Andrew G.; Choe, Gina H.; Naqvi, Hanyia; Zhang, Margaret; Sharma, Anu

2016-01-01

Endometrial cancer develops during exposure to estrogen unopposed by progesterone. Traditional formulations for menopausal hormone therapy include a progestin in women with a uterus. However, progestin exposure increases breast cancer risk in postmenopausal women. Alternatives to progestin include bazedoxifene (BZA), a selective estrogen receptor modulator, which prevents estrogen induced endometrial hyperplasia in clinical trials. Molecular mechanisms responsible for BZA's antiproliferative effect are not fully elucidated. We profiled endometrial adenocarcinoma, hyperplasia, and normal proliferative endometrium for differential expression in genes known to be regulated by estrogens or progesterone. Fibroblast growth factor (FGF)18, a paracrine growth factor promoting epithelial proliferation, was significantly increased in adenocarcinoma. Progesterone represses FGF18 by inducing heart and neural crest derivatives expressed transcript 2 (HAND2) in stromal cells. Notably, we confirmed lower HAND2 mRNA in adenocarcinoma, along with higher FGF tyrosine kinase receptor 2 and E74-like factor 5, collectively promoting FGF18 activity. We hypothesized BZA reduces epithelial proliferation by inhibiting FGF18 synthesis in stromal cells. To determine whether BZA regulates FGF18, we treated primary stromal cells with BZA or vehicle. In vitro, BZA reduced FGF18, but did not affect, HAND2. CD1 female mice received either BZA, conjugated estrogen (CE), or combined BZA/CE for 8 weeks. CE-treated mice had nearly 3-fold higher FGF18 expression. In contrast, BZA-treated mice, alone or with CE, had similar FGF18 as controls. Unexpectedly, BZA, alone or with CE, reduced HAND2 more than 80%, differing from progesterone regulation. Reduction of FGF18 is a potential mechanism by which BZA reduces endometrial proliferation and hyperplasia induced by estrogens. However, BZA works independently of HAND2, revealing a novel mechanism for progestin-free hormone therapy in postmenopausal women. PMID:27267714

Estrogens enhance myoblast differentiation in facioscapulohumeral muscular dystrophy by antagonizing DUX4 activity

PubMed Central

Teveroni, Emanuela; Sacconi, Sabrina; Calandra, Patrizia; Cascino, Isabella; Puma, Angela; Garibaldi, Matteo; Morosetti, Roberta; Ricci, Enzo; Trevisan, Carlo Pietro; Galluzzi, Giuliana; Pontecorvi, Alfredo; Deidda, Giancarlo

2017-01-01

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant neuromuscular disorder that is characterized by extreme variability in symptoms, with females being less severely affected than males and presenting a higher proportion of asymptomatic carriers. The sex-related factors involved in the disease are not known. Here, we have utilized myoblasts isolated from FSHD patients (FSHD myoblasts) to investigate the effect of estrogens on muscle properties. Our results demonstrated that estrogens counteract the differentiation impairment of FSHD myoblasts without affecting cell proliferation or survival. Estrogen effects are mediated by estrogen receptor β (ERβ), which reduces chromatin occupancy and transcriptional activity of double homeobox 4 (DUX4), a protein whose aberrant expression has been implicated in FSHD pathogenesis. During myoblast differentiation, we observed that the levels and activity of DUX4 increased progressively and were associated with its enhanced recruitment in the nucleus. ERβ interfered with this recruitment by relocalizing DUX4 in the cytoplasm. This work identifies estrogens as a potential disease modifier that underlie sex-related differences in FSHD by protecting against myoblast differentiation impairments in this disease. PMID:28263188

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 cognate elements.

The Distinct Effects of Estrogen and Hydrostatic Pressure on Mesenchymal Stem Cells Differentiation: Involvement of Estrogen Receptor Signaling.

PubMed

Zhao, Ying; Yi, Fei-Zhou; Zhao, Yin-Hua; Chen, Yong-Jin; Ma, Heng; Zhang, Min

2016-10-01

This study aimed to investigate the differential and synergistic effects of mechanical stimulation and estrogen on the proliferation and osteogenic or chondrogenic differentiation potential of bone marrow mesenchymal stem cells (BMSCs) and the roles of estrogen receptor (ER) in them. BMSCs were isolated and cultured using the whole bone marrow adherence method, and flow cytometry was used to identify the surface marker molecules of BMSCs. Cells were pre-treated with 1 nM 17β-estradiol or 1 nM of the estrogen receptor antagonist tamoxifen. Then, the cells were stimulated with hydrostatic pressure. Assessment included flow cytometry analysis of the cell cycle; immunofluorescent staining for F-actin; protein quantification for MAPK protein; and mRNA analysis for Col I, OCN, OPN and BSP after osteogenic induction and Sox-9, Aggrecan and Col-II after chondrogenic induction. Hydrostatic pressure (90 kPa/1 h) and 1 nM 17β-estradiol enhanced the cellular proliferation ability and the cytoskeleton activity but without synergistic biological effects. Estrogen activated ERKs and JNKs simultaneously and promoted the osteogenic differentiation, whereas the pressure just caused JNK-1/2 activation and promoted the chondrogenic differentiation of BMSCs. Estrogen had antagonism effect on chondrogenic promotion of hydrostatic pressure. Mechanobiological effects of hydrostatic pressure are closely associated with ERα activity. MAPK molecules and F-actin were likely to be important mediator molecules in the ER-mediated mechanotransduction of BMSCs.

Genistein and bisphenol A exposure cause estrogen receptor 1 to bind thousands of sites in a cell type-specific manner

PubMed Central

Gertz, Jason; Reddy, Timothy E.; Varley, Katherine E.; Garabedian, Michael J.; Myers, Richard M.

2012-01-01

Endogenous estrogens that are synthesized in the body impact gene regulation by activating estrogen receptors in diverse cell types. Exogenous compounds that have estrogenic properties can also be found circulating in the blood in both children and adults. The genome-wide impact of these environmental estrogens on gene regulation is unclear. To obtain an integrated view of gene regulation in response to environmental and endogenous estrogens on a genome-wide scale, we performed ChIP-seq to identify estrogen receptor 1 (ESR1; previously estrogen receptor α) binding sites, and RNA-seq in endometrial cancer cells exposed to bisphenol A (BPA; found in plastics), genistein (GEN; found in soybean), or 17β-estradiol (E2; an endogenous estrogen). GEN and BPA treatment induces thousands of ESR1 binding sites and >50 gene expression changes, representing a subset of E2-induced gene regulation changes. Genes affected by E2 were highly enriched for ribosome-associated proteins; however, GEN and BPA failed to regulate most ribosome-associated proteins and instead enriched for transporters of carboxylic acids. Treatment-dependent changes in gene expression were associated with treatment-dependent ESR1 binding sites, with the exception that many genes up-regulated by E2 harbored a BPA-induced ESR1 binding site but failed to show any expression change after BPA treatment. GEN and BPA exhibited a similar relationship to E2 in the breast cancer line T-47D, where cell type specificity played a much larger role than treatment specificity. Overall, both environmental estrogens clearly regulate gene expression through ESR1 on a genome-wide scale, although with lower potency resulting in less ESR1 binding sites and less gene expression changes compared to the endogenous estrogen, E2. PMID:23019147

Comparative effects of neonatal diethylstilbestrol on external genitalia development in adult males of two mouse strains with differential estrogen sensitivity

PubMed Central

Mahawong, Phitsanu; Sinclair, Adriane; Li, Yi; Schlomer, Bruce; Rodriguez, Esequiel; Ferretti, Max M.; Liu, Baomai; Baskin, Laurence S.; Cunha, Gerald R.

2014-01-01

The effect of neonatal exposure to diethylstilbestrol (DES), a potent synthetic estrogen, was examined to evaluate whether the CD-1 (estrogen insensitive, outbred) and C57 (estrogen sensitive, inbred) mouse strains differ in their response to estrogen disruption of male ExG differentiation. CD-1 and C57BL/6 litters were injected with sesame oil or DES (200 ng/g/5μl in sesame oil vehicle) every other day from birth to day 10. Animals were sacrificed at the following time points: birth, 5, 10 and 60 days postnatal. Neonatally DES-treated mice from both strains had many ExG abnormalities that included the following: (a) severe truncation of the prepuce and glans penis, (b) an abnormal urethral meatus, (c) ventral tethering of the penis, (d) reduced os penis length and glans width, (e) impaired differentiation of cartilage, (f) absence of urethral flaps, and (g) impaired differentiation of erectile bodies. Adverse effects of DES correlated with the expression of estrogen receptors within the affected tissues. While the effects of DES were similar in the more estrogen-sensitive C57BL/6 mice versus the less estrogen-sensitive CD-1 mice, the severity of DES effects was consistently greater in C57BL/6 mice. We suggest that many of the effects of DES, including the induction of hypospadias, are due to impaired growth and tissue fusion events during development. PMID:25449353

Gene expression profiles of estrogen receptors α and β in the fetal bovine hypothalamus and immunohistochemical characterization during development.

PubMed

Panin, M; Corain, L; Montelli, S; Cozzi, B; Peruffo, A

2015-02-01

Steroid hormones intervene in the structural and functional regulation of neuronal processes during development and thus determine brain differentiation. The effects of estrogens are mediated by two transcription factors, namely estrogen receptor α (ER-α) and estrogen receptor β (ER-β), that regulate the expression of target genes through their binding to specific DNA target sequences. We describe the mRNA expression of ER-α and ER-β in the hypothalamus of developing male and female bovines as revealed by quantitative real-time polymerase chain reaction, and the distribution of the two ERs in hypothalamic sections of all fetal stages as shown by immunohistochemistry. The expression profiles of the mRNAs of both ERs are mutually correlated throughout the gestation period, and their levels increase significantly in the last stages of gestation. No sexual differences in the mRNA expression of either ER-α or ER-β have been found in our fetal specimens. The use of specific antisera against ER-α and ER-β has allowed us to characterize and confirm the distribution of these receptors in the hypothalami of all fetal stages considered. Our results offer detailed information concerning the distribution of ER-α and ER-β in the developing bovine hypothalamus and provide additional insights into the processes involved in the hypothalamic development of a mammal with a long gestation and a highly gyrencephalic brain.

Differential tissue distribution, developmental programming, estrogen regulation and promoter characteristics of cyp19 genes in teleost fish.

PubMed

Callard, G V; Tchoudakova, A V; Kishida, M; Wood, E

2001-12-01

Teleost fish are characterized by exceptionally high levels of brain estrogen biosynthesis when compared to the brains of other vertebrates or to the ovaries of the same fish. Goldfish (Carassius auratus) and zebrafish (Danio rerio) have utility as complementary models for understanding the molecular basis and functional significance of exaggerated neural estrogen biosynthesis. Multiple cytochrome P450 aromatase (P450arom) cDNAs that derive from separate gene loci (cyp19a and cyp19b) are differentially expressed in brain (P450aromB>A) and ovary (P450aromA>B) and have a different developmental program (B>A) and response to estrogen upregulation (B only). As measured by increased P450aromB mRNA, a functional estrogen response system is first detected 24-48 h post-fertilization (hpf), consistent with the onset of estrogen receptor (ER) expression (alpha, beta, and gamma). The 5'-flanking region of the cyp19b gene has a TATA box, two estrogen response elements (EREs), an ERE half-site (ERE1/2), a nerve growth factor inducible-B protein (NGFI-B)/Nur77 responsive element (NBRE) binding site, and a sequence identical to the zebrafish GATA-2 gene neural specific enhancer. The cyp19a promoter region has TATA and CAAT boxes, a steroidogenic factor-1 (SF-1) binding site, and two aryl hydrocarbon receptor (AhR)/AhR nuclear translocator factor (ARNT) binding motifs. Both genes have multiple potential SRY/SOX binding sites (16 and 8 in cyp19b and cyp19a, respectively). Luciferase reporters have basal promoter activity in GH3 cells, but differences (a>b) are opposite to fish pituitary (b>a). When microinjected into fertilized zebrafish eggs, a cyp19b promoter-driven green fluorescent protein (GFP) reporter (but not cyp19a) is expressed in neurons of 30-48 hpf embryos, most prominently in retinal ganglion cells (RGCs) and their projections to optic tectum. Further studies are required to identify functionally relevant cis-elements and cellular factors, and to determine the regulatory role of estrogen in neurodevelopment.

Nuclear Receptor Co-Regulator Krüppel-like Factor 9 in Human Endometrial Stromal Cell Differentiation

USDA-ARS?s Scientific Manuscript database

The biological actions of ligand-bound estrogen (E) and progesterone (P) receptors are dependent on coregulator partner proteins. We have identified Krüppel-like Factor 9 (KLF9) as important for E and P actions in endometrial cells. Ablation of KLF9 in mice resulted in subfertility due partly to alt...

Dysregulation of Notch and ERα signaling in AhR−/− male mice

PubMed Central

Huang, Bo; Butler, Ryan; Miao, Yifei; Dai, Yubing; Wu, Wanfu; Su, Wen; Fujii-Kuriyama, Yoshiaki; Warner, Margaret; Gustafsson, Jan-Åke

2016-01-01

The aryl hydrocarbon receptor (AhR) is now recognized as an important physiological regulator in the immune and reproductive systems, and in the development of the liver and vascular system. AhR regulates cell cycle, cell proliferation, and differentiation through interacting with other signaling pathways, like estrogen receptor α (ERα), androgen receptor (AR), and Notch signaling. In the present study, we investigated Notch and estrogen signaling in AhR−/− mice. We found low fertility with degenerative changes in the testes, germ cell apoptosis, and a reduced number of early spermatids. There was no change in aromatase, AR, ERα, or ERβ expression in the testis and no detectable change in serum estrogen levels. However, expression of Notch receptors (Notch1 and Notch3) and their target Hairy and Enhancer of Split homolog 1 (HES1) was reduced. In addition, the testosterone level was slightly reduced in the serum. In the mammary fat pad, AhR appeared to regulate estrogen signaling because, in AhR−/− males, there was significant growth of the mammary ducts with high expression of ERα in the ductal epithelium. The enhanced mammary ductal growth appears to be related to overexpression of ERα accompanied by a high proliferation index, whereas the reduced fertility appears to be related defects in Notch signaling that leads to reduced expression of HES1 and, consequently, early maturation of spermatocytes and a depletion of primary spermatids. Previous reports have indicated that AhR pathway is associated with infertility in men. Our results provide a mechanistic explanation for this defect. PMID:27688768

THE OXYTOCIN-BONE AXIS

PubMed Central

Colaianni, G.; Tamma, R.; Di Benedetto, A.; Yuen, T.; Sun, L.; Zaidi, M.; Zallone, A.

2014-01-01

We recently demonstrated a direct action of oxytocin (OT) on skeletal homeostasis mainly mediated through stimulation of osteoblasts (OBs) formation and through the reciprocal modulation of osteoclast (OCs) formation and function. Thus, mice lacking the hormone or its receptor develop a low turnover osteoporosis that worsens with age in both sexes. The skeleton of OT and OT receptor (Oxtr) null mice display a pronounced decrease in vertebral and femoral trabecular volume. At cellular level OBs from OT−/− and Oxtr−/− mice exhibit lower mineralization activity and, at mRNA level, all master genes for osteoblast differentiation are down regulated. Moreover, OT has dual effects on OCs: it increases osteoclast formation both directly, by activating NF-kB and MAP kinase signaling, and indirectly, through the up-regulation of RANK-L synthesis by OBs. On the other hand, it inhibits bone resorption by triggering cytosolic Ca2+ release and nitric oxide synthesis in mature OCs. OT is locally produced by osteoblasts acting as paracrine-autocrine regulator of bone formation modulated by estrogens. The estrogen signal involved in this feed forward circuit is non genomic, since it requires an intact MAPK kinase signal transduction pathway, instead of the classical nuclear translocation of estrogen receptor. The ability of estrogen to increase bone mass in vivo is to an extent OTR-dependent. Thus Oxtr−/− mice injected 17β-estradiol did not show any effects on bone formation parameters, while the same treatment increases trabecular and cortical bone in wild type mice. An intact OT autocrine-paracrine circuit seems to be essential for optimal skeletal remodeling. PMID:24219627

STAR and AKR1B10 are down-regulated in high-grade endometrial cancer.

PubMed

Sinreih, Maša; Štupar, Saša; Čemažar, Luka; Verdenik, Ivan; Frković Grazio, Snježana; Smrkolj, Špela; Rižner, Tea Lanišnik

2017-07-01

Endometrial cancer is the most frequent gynecological malignancy in the developed world. The majority of cases are estrogen dependent, and are associated with diminished protective effects of progesterone. Endometrial cancer is also related to enhanced inflammation and decreased differentiation. In our previous studies, we examined the expression of genes involved in estrogen and progesterone actions in inflammation and tumor differentiation, in tissue samples from endometrial cancer and adjacent control endometrium. The aims of the current study were to examine correlations between gene expression and several demographic characteristics, and to evaluate changes in gene expression with regard to histopathological and clinical characteristics of 51 patients. We studied correlations and differences in expression of 38 genes involved in five pathophysiological processes: (i) estrogen-stimulated proliferation; (ii) estrogen-dependent carcinogenesis; (iii) diminished biosynthesis of progesterone: (iv) enhanced formation of progesterone metabolites; and (v) increased inflammation and decreased differentiation. Spearman correlation coefficient analysis shows that expression of PAQR7 correlates with age, expression of SRD5A1, AKR1B1 and AKR1B10 correlate with body mass, while expression of SRD5A1 and AKR1B10 correlate with body mass index. When patients with endometrial cancer were stratified based on menopausal status, histological grade, myometrial invasion, lymphovascular invasion, and FIGO stage, Mann-Whitney U tests revealed significantly decreased expression of STAR (4.4-fold; adjusted p=0.009) and AKR1B10 (9-fold; adjusted p=0.003) in high grade versus low grade tumors. Lower levels of STAR might lead to decreased de-novo steroid hormone synthesis and tumor differentiation, and lower levels of AKR1B10 to diminished elimination of toxic electrophilic carbonyl compounds in high-grade endometrial cancer. These data thus reveal the potential of STAR and AKR1B10 as prognostic biomarkers, which calls for further validation at the protein level. Copyright © 2017 Elsevier Ltd. All rights reserved.

GAS6 is an estrogen-inducible gene in mammary epithelial cells

PubMed Central

Mo, Rigen; Zhu, Yiwei Tony; Zhang, Zhongyi; Rao, Sambasiva M.; Zhu, Yi-Jun

2007-01-01

To identify estrogen responsive genes in mammary glands, microarray assays were performed. Twenty genes were found to be up-regulated while 16 genes were repressed in the 9h estrogen treated glands. The induction of GAS6, one of the genes up-regulated by estrogen, was confirmed by RNase protection assay. Furthermore, GAS6 was also demonstrated to be induced by estrogen in ER positive breast cancer cells. Analysis of GAS6 promoter revealed that GAS6 promoter was regulated by estrogen. An estrogen response element (ERE) was identified in the GAS6 promoter. Electrophoretic mobility shift assay revealed that ERα interacted with the ERE in the GAS6 promoter. Chromatin immunoprecipitation demonstrated that ERα was recruited to the GAS6 promoter upon estrogen stimulation. These results suggested that GAS6 is an estrogen target gene in mammary epithelial cells. PMID:17174935

The Oxysterol, 27-Hydroxycholesterol, Links Cholesterol Metabolism to Bone Homeostasis Through Its Actions on the Estrogen and Liver X Receptors

PubMed Central

Nelson, Erik R.; DuSell, Carolyn D.; Wang, Xiaojuan; Howe, Matthew K.; Evans, Glenda; Michalek, Ryan D.; Umetani, Michihisa; Rathmell, Jeffrey C.; Khosla, Sundeep; Gesty-Palmer, Diane

2011-01-01

Osteoporosis and age-related bone loss are important public health concerns. Therefore, there is a high level of interest in the development of medical interventions and lifestyle changes that reduce the incidence of osteoporosis and age-related bone loss. Decreased bone mineral density is associated with high cholesterol, and patients on statins have increased bone mineral densities, strongly implicating cholesterol as a negative regulator of bone homeostasis. In this study, using both molecular and pharmacological approaches, we have been able to demonstrate that the primary cholesterol metabolite, 27-hydroxycholesterol, through its actions on both estrogen receptors and liver X receptors, decreases osteoblast differentiation and enhances osteoclastogenesis, resulting in increased bone resorbtion in mice. Induction of the short heterodimer partner protein by estrogens in osteoblasts can attenuate the liver X receptor-mediated actions of 27-hydroxycholesterol in bone. These data establish a mechanistic link between cholesterol and bone quality, highlight an unexpected target of estrogens in osteoblasts, and define a signaling axis, the therapeutic exploitation of which is likely to yield novel antiosteoporotic drugs. PMID:21933863

Estrogen: A master regulator of bioenergetic systems in the brain and body

PubMed Central

Rettberg, Jamaica R; Yao, Jia; Brinton, Roberta Diaz

2014-01-01

Estrogen is a fundamental regulator of the metabolic system of the female brain and body. Within the brain, estrogen regulates glucose transport, aerobic glycolysis, and mitochondrial function to generate ATP. In the body, estrogen protects against adiposity, insulin resistance, and type II diabetes, and regulates energy intake and expenditure. During menopause, decline in circulating estrogen is coincident with decline in brain bioenergetics and shift towards a metabolically compromised phenotype. Compensatory bioenergetic adaptations, or lack thereof, to estrogen loss could determine risk of late-onset Alzheimer’s disease. Estrogen coordinates brain and body metabolism, such that peripheral metabolic state can indicate bioenergetic status of the brain. By generating biomarker profiles that encompass peripheral metabolic changes occurring with menopause, individual risk profiles for decreased brain bioenergetics and cognitive decline can be created. Biomarker profiles could identify women at risk while also serving as indicators of efficacy of hormone therapy or other preventative interventions. PMID:23994581

Absence of ERRα in Female Mice Confers Resistance to Bone Loss Induced by Age or Estrogen-Deficiency

PubMed Central

Rabier, Bénédicte; Monfoulet, Laurent; Dine, Julien; Macari, Claire; Espallergues, Julie; Horard, Béatrice; Giguère, Vincent; Cohen-Solal, Martine; Chassande, Olivier; Vanacker, Jean-Marc

2009-01-01

Background ERRα is an orphan member of the nuclear hormone receptor superfamily, which acts as a transcription factor and is involved in various metabolic processes. ERRα is also highly expressed in ossification zones during mouse development as well as in human bones and cell lines. Previous data have shown that this receptor up-modulates the expression of osteopontin, which acts as an inhibitor of bone mineralization and whose absence results in resistance to ovariectomy-induced bone loss. Altogether this suggests that ERRα may negatively regulate bone mass and could impact on bone fragility that occurs in the absence of estrogens. Methods/Principal Findings In this report, we have determined the in vivo effect of ERRα on bone, using knock-out mice. Relative to wild type animals, female ERRαKO bones do not age and are resistant to bone loss induced by estrogen-withdrawal. Strikingly male ERRαKO mice are indistinguishable from their wild type counterparts, both at the unchallenged or gonadectomized state. Using primary cell cultures originating from ERRαKO bone marrow, we also show that ERRα acts as an inhibitor of osteoblast differentiation. Conclusion/Significance Down-regulating ERRα could thus be beneficial against osteoporosis. PMID:19936213

The G-Protein-Coupled Estrogen Receptor (GPER/GPR30) in Ovarian Granulosa Cell Tumors

PubMed Central

Heublein, Sabine; Mayr, Doris; Friese, Klaus; Jarrin-Franco, Maria Cristina; Lenhard, Miriam; Mayerhofer, Artur; Jeschke, Udo

2014-01-01

Ovarian granulosa cell tumors (GCTs) are thought to arise from cells of the ovarian follicle and comprise a rare entity of ovarian masses. We recently identified the G-protein-coupled estrogen receptor (GPER/GPR30) to be present in granulosa cells, to be regulated by gonadotropins in epithelial ovarian cancer and to be differentially expressed throughout folliculogenesis. Thus, supposing a possible role of GPER in GCTs, this study aimed to analyze GPER in GCTs. GPER immunoreactivity in GCTs (n = 26; n (primary diagnosis) = 15, n (recurrence) = 11) was studied and correlated with the main clinicopathological variables. Positive GPER staining was identified in 53.8% (14/26) of GCTs and there was no significant relation of GPER with tumor size or lymph node status. Those cases presenting with strong GPER intensity at primary diagnosis showed a significant reduced overall survival (p = 0.002). Due to the fact that GPER is regulated by estrogens, as well as gonadotropins, GPER may also be affected by endocrine therapies applied to GCT patients. Moreover, with our data supposing GPER to be associated with GCT prognosis, GPER might be considered as a possible confounder when assessing the efficacy of hormone-based therapeutic approaches in GCTs. PMID:25167139

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yu; Department of Obstetrics and Gynaecology, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4; Cheng, Jung-Chien

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.more » 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.« less

GPER mediates differential effects of estrogen on colon cancer cell proliferation and migration under normoxic and hypoxic conditions

PubMed Central

Bustos, Viviana; Nolan, Áine M.; Nijhuis, Anke; Harvey, Harry; Parker, Alexandra; Poulsom, Richard; McBryan, Jean; Thomas, Warren; Silver, Andrew; Harvey, Brian J.

2017-01-01

The estrogen receptor ERβ is the predominant ER subtype expressed in normal well-differentiated colonic epithelium. However, ERβ expression is lost under the hypoxic microenvironment as colorectal cancer (CRC) malignancy progresses. This raises questions about the role of signalling through other estrogen receptors such as ERα or G-protein coupled estrogen receptor (GPER, GPR30) by the estrogen 17β-estradiol (E2) under hypoxic conditions after ERβ is lost in CRC progression. We tested the hypothesis that E2 or hypoxia can act via GPER to contribute to the altered phenotype of CRC cells. GPER expression was found to be up-regulated by hypoxia and E2 in a panel of CRC cell lines. The E2-modulated gene, Ataxia telangiectasia mutated (ATM), was repressed in hypoxia via GPER signalling. E2 treatment enhanced hypoxia-induced expression of HIF1-α and VEGFA, but repressed HIF1-α and VEGFA expression under normoxic conditions. The expression and repression of VEGFA by E2 were mediated by a GPER-dependent mechanism. E2 treatment potentiated hypoxia-induced CRC cell migration and proliferation, whereas in normoxia, cell migration and proliferation were suppressed by E2 treatment. The effects of E2 on these cellular responses in normoxia and hypoxia were mediated by GPER. In a cohort of 566 CRC patient tumor samples, GPER expression significantly associated with poor survival in CRC Stages 3-4 females but not in the stage-matched male population. Our findings support a potentially pro-tumorigenic role for E2 in ERβ-negative CRC under hypoxic conditions transduced via GPER and suggest a novel route of therapeutic intervention through GPER antagonism. PMID:29137421

GPER mediates differential effects of estrogen on colon cancer cell proliferation and migration under normoxic and hypoxic conditions.

PubMed

Bustos, Viviana; Nolan, Áine M; Nijhuis, Anke; Harvey, Harry; Parker, Alexandra; Poulsom, Richard; McBryan, Jean; Thomas, Warren; Silver, Andrew; Harvey, Brian J

2017-10-13

The estrogen receptor ERβ is the predominant ER subtype expressed in normal well-differentiated colonic epithelium. However, ERβ expression is lost under the hypoxic microenvironment as colorectal cancer (CRC) malignancy progresses. This raises questions about the role of signalling through other estrogen receptors such as ERα or G-protein coupled estrogen receptor (GPER, GPR30) by the estrogen 17β-estradiol (E2) under hypoxic conditions after ERβ is lost in CRC progression. We tested the hypothesis that E2 or hypoxia can act via GPER to contribute to the altered phenotype of CRC cells. GPER expression was found to be up-regulated by hypoxia and E2 in a panel of CRC cell lines. The E2-modulated gene, Ataxia telangiectasia mutated ( ATM ), was repressed in hypoxia via GPER signalling. E2 treatment enhanced hypoxia-induced expression of HIF1-α and VEGFA, but repressed HIF1-α and VEGFA expression under normoxic conditions. The expression and repression of VEGFA by E2 were mediated by a GPER-dependent mechanism. E2 treatment potentiated hypoxia-induced CRC cell migration and proliferation, whereas in normoxia, cell migration and proliferation were suppressed by E2 treatment. The effects of E2 on these cellular responses in normoxia and hypoxia were mediated by GPER. In a cohort of 566 CRC patient tumor samples, GPER expression significantly associated with poor survival in CRC Stages 3-4 females but not in the stage-matched male population. Our findings support a potentially pro-tumorigenic role for E2 in ERβ-negative CRC under hypoxic conditions transduced via GPER and suggest a novel route of therapeutic intervention through GPER antagonism.

Establishment of estrogen receptor 1 (ESR1)-knockout medaka: ESR1 is dispensable for sexual development and reproduction in medaka, Oryzias latipes.

PubMed

Tohyama, Saki; Ogino, Yukiko; Lange, Anke; Myosho, Taijun; Kobayashi, Tohru; Hirano, Yu; Yamada, Gen; Sato, Tomomi; Tatarazako, Norihisa; Tyler, Charles R; Iguchi, Taisen; Miyagawa, Shinichi

2017-08-01

Estrogens play fundamental roles in regulating reproductive activities and they act through estrogen receptor (ESR) in all vertebrates. Most vertebrates have two ESR subtypes (ESR1 and ESR2), whereas teleost fish have at least three (Esr1, Esr2a and Esr2b). Intricate functionalization has been suggested among the Esr subtypes, but to date, distinct roles of Esr have been characterized in only a limited number of species. Study of loss-of-function in animal models is a powerful tool for application to understanding vertebrate reproductive biology. In the current study, we established esr1 knockout (KO) medaka using a TALEN approach and examined the effects of Esr1 ablation. Unexpectedly, esr1 KO medaka did not show any significant defects in their gonadal development or in their sexual characteristics. Neither male or female esr1 KO medaka exhibited any significant changes in sexual differentiation or reproductive activity compared with wild type controls. Interestingly, however, estrogen-induced vitellogenin gene expression, an estrogen-responsive biomarker in fish, was limited in the liver of esr1 KO males. Our findings, in contrast to mammals, indicate that Esr1 is dispensable for normal development and reproduction in medaka. We thus provide an evidence for estrogen receptor functionalization between mammals and fish. Our findings will also benefit interpretation of studies into the toxicological effects of estrogenic chemicals in fish. © 2017 Japanese Society of Developmental Biologists.

Differential expression of largemouth bass (Micropterus salmoides) estrogen receptor isotypes alpha, beta, and gamma by estradiol.

PubMed

Sabo-Attwood, Tara; Kroll, Kevin J; Denslow, Nancy D

2004-04-15

The expression levels of three estrogen receptor (ER) isotypes alpha, beta, and gamma were quantified in female largemouth bass (Micropterus salmoides) (LMB) liver, ovary, brain, and pituitary tissues. ER alpha and beta expression predominated in the liver, while ERs beta and gamma predominated in the other tissues. Temporally in females, ER alpha was highly up-regulated, ER gamma was slightly up-regulated, and ER beta levels remained unchanged in the liver when plasma 17-beta estradiol (E2) and vitellogenin (Vtg) levels were elevated in the spring. In ovarian tissue from these same fish, all three ERs were maximally expressed in the fall, during early oocyte development and prior to peak plasma E2 levels. When males were injected with E2, ER alpha was highly inducible, ER gamma was moderately up-regulated, and ER beta levels were not affected. None of the ER isotypes were induced by E2 in gonadal tissues. These results combined suggest that the ERs themselves are not regulated in the same manner by E2, and furthermore, do not contribute equally to the transcriptional regulation of genes involved in fish reproduction such as Vtg.

Estrogenic encounters: How interactions between aromatase and the environment modulate aggression

PubMed Central

Trainor, Brian C.; Kyomen, Helen H.; Marler, Catherine A.

2007-01-01

Initial investigations into the mechanistic basis of aggression focused on the role of testosterone (T) and a variety of studies on non-human animals found that elevated T levels promote aggression. However, many correlational studies have not detected a significant association between aggression and peripheral T levels. One reason for this inconsistency may be due to differential metabolism of T within the brain, in particular, the conversion of T to estrogen by aromatase. Thus, differences in aromatase enzyme activity, estrogen receptor expression, and related cofactors may have important effects on how steroids affect aggressive behavior. Hormone manipulation studies conducted in a wide variety of species indicate that estrogens modulate aggression. There is also growing evidence that social experience has important effects on the production of estrogen within the brain, and some cases can not be explained by androgenic regulation of aromatase. Such changes in central aromatase activity may play an important role in determining how social experiences affect the probability of whether an individual engages in aggressive behavior. Although studies have been conducted in many taxa, there has been relatively little integration between literatures examining aggression in different species. In this review, we compare and contrast studies examining aggression in birds, mammals, and humans. By taking an integrative approach to our review, we consider mechanisms that could explain species differences in how estrogen modulates aggression. PMID:16376420

Gonadal expression of Sf1 and aromatase during sex determination in the red-eared slider turtle (Trachemys scripta), a reptile with temperature-dependent sex determination.

PubMed

Ramsey, Mary; Shoemaker, Christina; Crews, David

2007-12-01

Many egg-laying reptiles have temperature-dependent sex determination (TSD), where the offspring sex is determined by incubation temperature during a temperature-sensitive period (TSP) in the middle third of development. The underlying mechanism transducing a temperature cue into an ovary or testis is unknown, but it is known that steroid hormones play an important role. During the TSP, exogenous application of estrogen can override a temperature cue and produce females, while blocking the activity of aromatase (Cyp19a1), the enzyme that converts testosterone to estradiol, produces males from a female-biased temperature. The production of estrogen is a key step in ovarian differentiation for many vertebrates, including TSD reptiles, and temperature-based differences in aromatase expression during the TSP may be a critical step in ovarian determination. Steroidogenic factor-1 (Sf1) is a key gene in vertebrate sex determination and regulates many steroidogenic enzymes, including aromatase. We find that Sf1 and aromatase are differentially expressed during sex determination in the red-eared slider turtle, Trachemys scripta elegans. Sf1 is expressed at higher levels during testis development while aromatase expression increases during ovary determination. We also assayed Sf1 and aromatase response to sex-reversing treatments via temperature or the modulation of estrogen availability. Sf1 expression was redirected to low-level female-specific patterns with feminizing temperature shift or exogenous estradiol application and redirected to more intense male-specific patterns with male-producing temperature shift or inhibition of aromatase activity. Conversely, aromatase expression was redirected to more intense female-specific patterns with female-producing treatment and redirected toward diffuse low-level male-specific patterns with masculinizing sex reversal. Our data do not lend support to a role for Sf1 in the regulation of aromatase expression during slider turtle sex determination, but do support a critical role for estrogen in ovarian development.

Isoliquiritigenin exhibits anti-proliferative properties in the pituitary independent of estrogen receptor function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weis, Karen E.; Raetzman, Lori T., E-mail: raetzma

The plant flavonoid isoliquiritigenin (ISL) is a botanical estrogen widely taken as an herbal supplement to ease the symptoms of menopause. ISL has been also shown to have anti-tumor properties in a number of cancer cell backgrounds. However, the effects of ISL on normal cells are less well known and virtually unstudied in the context of the pituitary gland. We have established a pituitary explant culture model to screen chemical agents for gene expression changes within the pituitary gland during a period of active proliferation and differentiation. Using this whole-organ culture system we found ISL to be weakly estrogenic basedmore » on its ability to induce Cckar mRNA expression, an estrogen receptor (ER) mediated gene. Using a range of ISL from 200 nM to 200 μM, we discovered that ISL promoted cell proliferation at a low concentration, yet potently inhibited proliferation at the highest concentration. ICI 182,780 failed to antagonize ISL's repression of pituitary cell proliferation, indicating the effect is independent of ER signaling. Coincident with a decrease in proliferating cells, we observed down-regulation of transcript for cyclin D2 and E2 and a strong induction of mRNA and protein for the cyclin dependent kinase inhibitor Cdkn1a (p21). Importantly, high dose ISL did not alter the balance of progenitor vs. differentiated cell types within the pituitary explants and they seemed otherwise healthy; however, TUNEL staining revealed an increase in apoptotic cell death in ISL treated cultures. Our results merit further examination of ISL as an anti-tumor agent in the pituitary gland. - Highlights: • Isoliquiritigenin possesses weak estrogenic activity based on induction of Cckar. • ISL can be anti-proliferative in pituitary explants without altering cell lineages. • Anti-proliferative behavior of ISL is not estrogen receptor mediated. • ISL induces p21 expression leading to cell cycle arrest and apoptosis.« less

Differential effects of progesterone and genital stimulation on sequential inhibition of estrous behavior and progesterone receptor expression in the rat brain.

PubMed

Gómez-Camarillo, Madaí A; Beyer, Carlos; Lucio, Rosa Angélica; García-Juárez, Marcos; González-Arenas, Aliesha; Camacho-Arroyo, Ignacio; Komisaruk, Barry R; González-Flores, Oscar

2011-05-30

The effect of genital stimulation, either by vaginocervical stimulation (VCS) using a calibrated vaginal probe combined with manual flank stimulation (FS), or by mounts performed by the male, on the hypothalamus and preoptic area concentration of the progesterone receptors A (PR-A) and B (PR-B) was assessed in ovariectomized (ovx) estrogen-primed rats. VCS/FS or stimulation provided by male mounts, even without intromission, significantly decreased PR-B concentration in the hypoythalamus. Down regulation of PR produced by genital stimulation was quantitatively similar to that elicited by progesterone (P) administration. Bilateral or unilateral transection of the pelvic or the pudendal nerves prevented down regulation elicited by VCS/FS. Repeated VCS/FS elicited lordosis behavior in most ovx estrogen primed rats, but the lordosis intensity was lower than that observed in response to P. P administered to ovx estrogen primed rats, induced sequential inhibition, i.e., failure to display estrous behavior in response to a second P injection (24h after the initial P injection). VCS/FS failed to elicit sequential inhibition, since rats responded with normal estrous behavior to the second injection of P. This suggests that down regulation by VCS, by contrast with P, failed to inhibit the subpopulation of PR involved in the facilitation of estrous behavior by P. Copyright © 2011 Elsevier Inc. All rights reserved.

Bisphenol-A induces expression of HOXC6, an estrogen-regulated homeobox-containing gene associated with breast cancer.

PubMed

Hussain, Imran; Bhan, Arunoday; Ansari, Khairul I; Deb, Paromita; Bobzean, Samara A M; Perrotti, Linda I; Mandal, Subhrangsu S

2015-06-01

HOXC6 is a homeobox-containing gene associated with mammary gland development and is overexpressed in variety of cancers including breast and prostate cancers. Here, we have examined the expression of HOXC6 in breast cancer tissue, investigated its transcriptional regulation via estradiol (E2) and bisphenol-A (BPA, an estrogenic endocrine disruptor) in vitro and in vivo. We observed that HOXC6 is differentially over-expressed in breast cancer tissue. E2 induces HOXC6 expression in cultured breast cancer cells and in mammary glands of Sprague Dawley rats. HOXC6 expression is also induced upon exposure to BPA both in vitro and in vivo. Estrogen-receptor-alpha (ERα) and ER-coregulators such as MLL-histone methylases are bound to the HOXC6 promoter upon exposure to E2 or BPA and that resulted in increased histone H3K4-trimethylation, histone acetylation, and recruitment of RNA polymerase II at the HOXC6 promoter. HOXC6 overexpression induces expression of tumor growth factors and facilitates growth 3D-colony formation, indicating its potential roles in tumor growth. Our studies demonstrate that HOXC6, which is a critical player in mammary gland development, is upregulated in multiple cases of breast cancer, and is transcriptionally regulated by E2 and BPA, in vitro and in vivo. Published by Elsevier B.V.

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…

Human uterine and placental arteries exhibit tissue-specific acute responses to 17β-estradiol and estrogen-receptor-specific agonists.

PubMed

Corcoran, Jemma J; Nicholson, Christopher; Sweeney, Michèle; Charnock, Jayne C; Robson, Stephen C; Westwood, Melissa; Taggart, Michael J

2014-05-01

The discrete regulation of vascular tone in the human uterine and placental circulations is a key determinant of appropriate uteroplacental blood perfusion and pregnancy success. Humoral factors such as estrogen, which increases in the placenta and maternal circulation throughout human pregnancy, may regulate these vascular beds as studies of animal arteries have shown that 17β-estradiol, or agonists of estrogen receptors (ER), can exert acute vasodilatory actions. The aim of this study was to compare how acute exposure to ER-specific agonists, and 17β-estradiol, altered human placental and uterine arterial tone in vitro. Uterine and placental arteries were isolated from biopsies obtained from women with uncomplicated pregnancy delivering a singleton infant at term. Vessels were mounted on a wire myograph, exposed to the thromboxane receptor agonist U46619 (10(-6) M), and then incubated with incremental doses (5 min, 0.03-30 µM) of either 17β-estradiol or agonists specific for the ERs ERα (PPT), ERβ (DPN) or the G-protein-coupled estrogen receptor GPER-1 (G1). ERα and ERβ mRNA expression was assessed. 17β-estradiol, PPT and DPN each relaxed myometrial arteries (P < 0.05) in a manner that was partly endothelium-dependent. In contrast, 17β-estradiol or DPN relaxed placental arteries (maximum relaxation to 42 ± 1.1 or 47.6 ± 6.53% of preconstriction, respectively) to a lesser extent than myometrial arteries (to 0.03 ± 0.03 or 8.0 ± 1.0%) and in an endothelial-independent manner whereas PPT was without effect. G1 exposure did not inhibit the constriction of myometrial nor placenta arteries. mRNA expression of ERα and ERβ was greater in myometrial arteries than placental arteries. ER-specific agonists, and 17β-estradiol, differentially modulate the tone of uterine versus placental arteries highlighting that estrogen may regulate human uteroplacental blood flow in a tissue-specific manner.

17β-Estradiol and ICI182,780 Differentially Regulate STAT5 Isoforms in Female Mammary Epithelium, With Distinct Outcomes

PubMed Central

Jallow, Fatou; Brockman, Jennifer L; Helzer, Kyle T; Rugowski, Debra E; Goffin, Vincent; Alarid, Elaine T; Schuler, Linda A

2018-01-01

Abstract Prolactin (PRL) and estrogen cooperate in lobuloalveolar development of the mammary gland and jointly regulate gene expression in breast cancer cells in vitro. Canonical PRL signaling activates STAT5A/B, homologous proteins that have different target genes and functions. Although STAT5A/B are important for physiological mammary function and tumor pathophysiology, little is known about regulation of their expression, particularly of STAT5B, and the consequences for hormone action. In this study, we examined the effect of two estrogenic ligands, 17β-estradiol (E2) and the clinical antiestrogen, ICI182,780 (ICI, fulvestrant) on expression of STAT5 isoforms and resulting crosstalk with PRL in normal and tumor murine mammary epithelial cell lines. In all cell lines, E2 and ICI significantly increased protein and corresponding nascent and mature transcripts for STAT5A and STAT5B, respectively. Transcriptional regulation of STAT5A and STAT5B by E2 and ICI, respectively, is associated with recruitment of estrogen receptor alpha and increased H3K27Ac at a common intronic enhancer 10 kb downstream of the Stat5a transcription start site. Further, E2 and ICI induced different transcripts associated with differentiation and tumor behavior. In tumor cells, E2 also significantly increased proliferation, invasion, and stem cell-like activity, whereas ICI had no effect. To evaluate the role of STAT5B in these responses, we reduced STAT5B expression using short hairpin (sh) RNA. shSTAT5B blocked ICI-induced transcripts associated with metastasis and the epithelial mesenchymal transition in both cell types. shSTAT5B also blocked E2-induced invasion of tumor epithelium without altering E2-induced transcripts. Together, these studies indicate that STAT5B mediates a subset of protumorigenic responses to both E2 and ICI, underscoring the need to understand regulation of its expression and suggesting exploration as a possible therapeutic target in breast cancer. PMID:29594259

Estrogen: a master regulator of bioenergetic systems in the brain and body.

PubMed

Rettberg, Jamaica R; Yao, Jia; Brinton, Roberta Diaz

2014-01-01

Estrogen is a fundamental regulator of the metabolic system of the female brain and body. Within the brain, estrogen regulates glucose transport, aerobic glycolysis, and mitochondrial function to generate ATP. In the body, estrogen protects against adiposity, insulin resistance, and type II diabetes, and regulates energy intake and expenditure. During menopause, decline in circulating estrogen is coincident with decline in brain bioenergetics and shift towards a metabolically compromised phenotype. Compensatory bioenergetic adaptations, or lack thereof, to estrogen loss could determine risk of late-onset Alzheimer's disease. Estrogen coordinates brain and body metabolism, such that peripheral metabolic state can indicate bioenergetic status of the brain. By generating biomarker profiles that encompass peripheral metabolic changes occurring with menopause, individual risk profiles for decreased brain bioenergetics and cognitive decline can be created. Biomarker profiles could identify women at risk while also serving as indicators of efficacy of hormone therapy or other preventative interventions. Copyright © 2013 Elsevier Inc. All rights reserved.

Octylphenol (OP) alters the expression of members of the amyloid protein family in the hypothalamus of the snapping turtle, Chelydra serpentina serpentina.

PubMed Central

Trudeau, Vance L; Chiu, Suzanne; Kennedy, Sean W; Brooks, Ronald J

2002-01-01

The gonadal estrogen estradiol-17beta (E(2)) is important for developing and regulating hypothalamic function and many aspects of reproduction in vertebrates. Pollutants such as octylphenol (OP) that mimic the actions of estrogens are therefore candidate endocrine-disrupting chemicals. We used a differential display strategy (RNA-arbitrarily primed polymerase chain reaction) to isolate partial cDNA sequences of neurotransmitter, developmental, and disease-related genes that may be regulated by OP or E(2) in the snapping turtle Chelydra serpentina serpentina hypothalamus. Hatchling and year-old male snapping turtles were exposed to a 10 ng/mL nominal concentration of waterborne OP or E(2) for 17 days. One transcript [421 base pairs (bp)] regulated by OP and E(2) was 93% identical to human APLP-2. APLP-2 and the amyloid precursor protein (APP) regulate neuronal differentiation and are also implicated in the genesis of Alzheimer disease in humans. Northern blot analysis determined that the turtle hypothalamus contains a single APLP-2 transcript of 3.75 kb in length. Exposure to OP upregulated hypothalamic APLP-2 mRNA levels 2-fold (p < 0.05) in month-old and yearling turtles. E(2) did not affect APLP-2 mRNA levels in hatchlings but stimulated a 2-fold increase (p < 0.05) in APLP-2 mRNA levels in yearling males. The protein beta-amyloid, a selectively processed peptide derived from APP, is also involved in neuronal differentiation, and accumulation of this neurotoxic peptide causes neuronal degeneration in the brains of patients with Alzheimer disease. Therefore, we also sought to determine the effects of estrogens on the expression of beta-amyloid. Using homology cloning based on known sequences, we isolated a cDNA fragment (474 bp) from turtle brain with 88% identity to human APP. Northern blot analysis determined that a single 3.5-kb transcript was expressed in the turtle hypothalamus. Waterborne OP also increased the expression of hypothalamic APP after 35 days of exposure. Our results indicate that low levels of OP are bioactive and can alter the expression of APLP-2 and APP. Because members of the APP gene family are involved in neuronal development, we hypothesize that OP exposure may disrupt hypothalamic development in young turtles. PMID:11882478

Octylphenol (OP) alters the expression of members of the amyloid protein family in the hypothalamus of the snapping turtle, Chelydra serpentina serpentina.

PubMed

Trudeau, Vance L; Chiu, Suzanne; Kennedy, Sean W; Brooks, Ronald J

2002-03-01

The gonadal estrogen estradiol-17beta (E(2)) is important for developing and regulating hypothalamic function and many aspects of reproduction in vertebrates. Pollutants such as octylphenol (OP) that mimic the actions of estrogens are therefore candidate endocrine-disrupting chemicals. We used a differential display strategy (RNA-arbitrarily primed polymerase chain reaction) to isolate partial cDNA sequences of neurotransmitter, developmental, and disease-related genes that may be regulated by OP or E(2) in the snapping turtle Chelydra serpentina serpentina hypothalamus. Hatchling and year-old male snapping turtles were exposed to a 10 ng/mL nominal concentration of waterborne OP or E(2) for 17 days. One transcript [421 base pairs (bp)] regulated by OP and E(2) was 93% identical to human APLP-2. APLP-2 and the amyloid precursor protein (APP) regulate neuronal differentiation and are also implicated in the genesis of Alzheimer disease in humans. Northern blot analysis determined that the turtle hypothalamus contains a single APLP-2 transcript of 3.75 kb in length. Exposure to OP upregulated hypothalamic APLP-2 mRNA levels 2-fold (p < 0.05) in month-old and yearling turtles. E(2) did not affect APLP-2 mRNA levels in hatchlings but stimulated a 2-fold increase (p < 0.05) in APLP-2 mRNA levels in yearling males. The protein beta-amyloid, a selectively processed peptide derived from APP, is also involved in neuronal differentiation, and accumulation of this neurotoxic peptide causes neuronal degeneration in the brains of patients with Alzheimer disease. Therefore, we also sought to determine the effects of estrogens on the expression of beta-amyloid. Using homology cloning based on known sequences, we isolated a cDNA fragment (474 bp) from turtle brain with 88% identity to human APP. Northern blot analysis determined that a single 3.5-kb transcript was expressed in the turtle hypothalamus. Waterborne OP also increased the expression of hypothalamic APP after 35 days of exposure. Our results indicate that low levels of OP are bioactive and can alter the expression of APLP-2 and APP. Because members of the APP gene family are involved in neuronal development, we hypothesize that OP exposure may disrupt hypothalamic development in young turtles.

Estrogens regulate the expression of NHERF1 in normal colon during the reproductive cycle of Wistar rats.

PubMed

Cuello-Carrión, F Darío; Troncoso, Mariana; Guiñazu, Elina; Valdez, Susana R; Fanelli, Mariel A; Ciocca, Daniel R; Kreimann, Erica L

2010-12-01

In breast cancer cell lines, the Na(+)/H(+) exchanger regulator factor 1 (NHERF1) gene is regulated at the transcriptional level by estrogens, the protein expression levels correlate with the presence of estrogen receptors and the effect is blocked by anti-estrogens. However, there is limited information regarding the regulation of NHERF1 by estrogens in normal colon tissue. The NHERF1 protein has an important role in the maintenance of the intestine ultrastructure. NHERF1-deficient mice showed defects in the intestinal microvilli as well as molecular alterations in brush border membrane proteins. Here, we have studied the expression of NHERF1 in normal rat colon and uterus during the reproductive cycle of Wistar rats. We found that NHERF1 expression in rat colon during the estral cycle is modified by estrogen levels: higher expression of NHERF1 was observed during the proestrous and estrous stages and lower expression in diestrous 1 when estrogen levels decreased. In uterus, NHERF1 was expressed in the apical region of the luminal epithelium and glands in all stages of the estral cycle, and in both colon and uterus, the expression was independent of the proliferation status. Our results show that NHERF1 expression is regulated by estrogens in colon during the rat estral cycle.

Fluorescence anisotropy microplate assay to investigate the interaction of full-length steroid receptor coactivator-1a with steroid receptors

PubMed Central

Zhang, Chen; Nordeen, Steven K.; Shapiro, David J.

2013-01-01

Estrogens, acting via estrogen receptor (ER) play key roles in growth, differentiation and gene regulation in the reproductive, central nervous and skeletal systems. ER-mediated gene transcription contributes to the development and spread of breast, uterine, and liver cancer. Steroid receptor coactivator-1a (SRC1a) belongs to the P160 family of coactivators, which is the best known of the many coactivators implicated in ER-mediated transactivation. Binding of full-length P160 coactivators to steroid receptors has been difficult to investigate in vitro. This chapter details how to investigate the interaction of SRC1a with ER using the fluorescence anisotropy/polarization microplate assay (FAMA). PMID:23436375

Differential regulation of HIF-1α and HIF-2α in neuroblastoma: Estrogen-related receptor alpha (ERRα) regulates HIF2A transcription and correlates to poor outcome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamidian, Arash; Stedingk, Kristoffer von; Munksgaard Thorén, Matilda

2015-06-05

Hypoxia-inducible factors (HIFs) are differentially regulated in tumor cells. While the current paradigm supports post-translational regulation of the HIF-α subunits, we recently showed that hypoxic HIF-2α is also transcriptionally regulated via insulin-like growth factor (IGF)-II in the childhood tumor neuroblastoma. Here, we demonstrate that transcriptional regulation of HIF-2α seems to be restricted to neural cell-derived tumors, while HIF-1α is canonically regulated at the post-translational level uniformly across different tumor forms. Enhanced expression of HIF2A mRNA at hypoxia is due to de novo transcription rather than increased mRNA stability, and chemical stabilization of the HIF-α proteins at oxygen-rich conditions unexpectedly leadsmore » to increased HIF2A transcription. The enhanced HIF2A levels do not seem to be dependent on active HIF-1. Using a transcriptome array approach, we identified members of the Peroxisome proliferator-activated receptor gamma coactivator (PGC)/Estrogen-related receptor (ERR) complex families as potential regulators of HIF2A. Knockdown or inhibition of one of the members, ERRα, leads to decreased expression of HIF2A, and high expression of the ERRα gene ESRRA correlates with poor overall and progression-free survival in a clinical neuroblastoma material consisting of 88 tumors. Thus, targeting of ERRα and pathways regulating transcriptional HIF-2α are promising therapeutic avenues in neuroblastoma. - Highlights: • Transcriptional control of HIF-2α is restricted to neural cell-derived tumors. • Enhanced transcription of HIF2A is not due to increased mRNA stability. • Chemical stabilization of the HIF-α subunits leads to increased HIF2A transcription. • ERRα regulates HIF2A mRNA expression in neuroblastoma. • High expression of ESRRA correlates to poor outcome in neuroblastoma.« less

Effects of phytoestrogens and environmental estrogens on osteoblastic differentiation in MC3T3-E1 cells.

PubMed

Kanno, Sanae; Hirano, Seishiro; Kayama, Fujio

2004-03-01

Phytoestrogens and environmental estrogens, which have in part some structural similarity to 17beta-estradiol, are reported to act as agonists/antagonists of estrogen in animals and humans. Estrogen is known to play an important role in maintaining bone mass, since the concentration of serum estrogen decreases after menopause and the estrogen deficiency results in bone loss. In this study, we report the effects of phytoestrogens (genistein, daidzein, and coumestrol) and environmental estrogens (bisphenol A (BPA), p-n-nonylphenol (NP) and bis(2-ethylhexyl)phthalate (DEHP)) on osteoblast differentiation using MC3T3-E1 cells, a mouse calvaria osteoblast-like cell line. Coumestrol (10(-10) to 10(-6)M) slightly enhanced cell proliferation, while neither the other phytoestrogens (daidzein, genistein) nor environmental estrogens increased cell proliferation. Alkaline phosphatase (ALP) activity and cellular calcium (Ca) and phosphorus (P) contents were increased by phytoestrogens and BPA; however, neither NP nor DEHP affected those osteoblastic indicators. The effects of estrogenic potency, using the cell proliferation of MCF-7 cells, an estrogen receptor (ER)-positive human breast cancer cell line, indicate that coumestrol has the highest estrogenic potency among those phytoestrogens and environmental estrogens. The estrogenic potency of NP and DEHP were lower than the others. In conclusion, phytoestrogens, such as coumestrol, genistein and daidzein, and BPA increased ALP activity and enhanced bone mineralization in MC3T3-E1 cells, suggesting that not only phytoestrogen but also BPA, an environmental estrogen, is implicated in bone metabolism.

Impact of Estrogens and Estrogen Receptor Alpha (ESR1) in Brain Lipid Metabolism.

PubMed

Morselli, Eugenia; de Souza Santos, Roberta; Gao, Su; Ávalos, Yenniffer; Criollo, Alfredo; Palmer, Biff F; Clegg, Deborah J

2018-03-06

Estrogens and their receptors play key roles in regulating body weight, energy expenditure, and metabolic homeostasis. It is known that lack of estrogens promotes increased food intake and induces the expansion of adipose tissues, for which much is known. An area of estrogenic research that has received less attention is the role of estrogens and their receptors in influencing intermediary lipid metabolism in organs such as the brain. In this review, we highlight the actions of estrogens and their receptors in regulating their impact on modulating fatty acid content, utilization, and oxidation through their direct impact on intracellular signaling cascades within the central nervous system.

Repression of osteoblast maturation by ERRα accounts for bone loss induced by estrogen deficiency.

PubMed

Gallet, Marlène; Saïdi, Soraya; Haÿ, Eric; Photsavang, Johann; Marty, Caroline; Sailland, Juliette; Carnesecchi, Julie; Tribollet, Violaine; Barenton, Bruno; Forcet, Christelle; Birling, Marie-Christine; Sorg, Tania; Chassande, Olivier; Cohen-Solal, Martine; Vanacker, Jean-Marc

2013-01-01

ERRα is an orphan member of the nuclear receptor family, the complete inactivation of which confers resistance to bone loss induced by ageing and estrogen withdrawal to female mice in correlation with increased bone formation in vivo. Furthermore ERRα negatively regulates the commitment of mesenchymal cells to the osteoblast lineage ex vivo as well as later steps of osteoblast maturation. We searched to determine whether the activities of ERRα on osteoblast maturation are responsible for one or both types of in vivo induced bone loss. To this end we have generated conditional knock out mice in which the receptor is normally present during early osteoblast differentiation but inactivated upon osteoblast maturation. Bone ageing in these animals was similar to that observed for control animals. In contrast conditional ERRαKO mice were completely resistant to bone loss induced by ovariectomy. We conclude that the late (maturation), but not early (commitment), negative effects of ERRα on the osteoblast lineage contribute to the reduced bone mineral density observed upon estrogen deficiency.

Estrogen Actions in the Brain and the Basis for Differential Action in Men and Women: A Case for Sex-Specific Medicines

PubMed Central

McArthur, Simon

2010-01-01

The classic view of estrogen actions in the brain was confined to regulation of ovulation and reproductive behavior in the female of all mamamalian species studied, including humans. Burgeoning evidence now documents profound effects of estrogens on learning, memory, and mood as well as neurodevelopmental and neurodegenerative processes. Most data derive from studies in females, but there is mounting recognition that estrogens play important roles in the male brain, where they can be generated from circulating testosterone by local aromatase enzymes or synthesized de novo by neurons and glia. Estrogen-based therapy therefore holds considerable promise for brain disorders that affect both men and women. However, as investigations are beginning to consider the role of estrogens in the male brain more carefully, it emerges that they have different, even opposite, effects as well as similar effects in male and female brains. This review focuses on these differences, including sex dimorphisms in the ability of estradiol to influence synaptic plasticity, neurotransmission, neurodegeneration, and cognition, which, we argue, are due in a large part to sex differences in the organization of the underlying circuitry. There are notable sex differences in the incidence and manifestations of virtually all central nervous system disorders, including neurodegenerative disease (Parkinson's and Alzheimer's), drug abuse, anxiety, and depression. Understanding the cellular and molecular basis of sex differences in brain physiology and responses to estrogen and estrogen mimics is, therefore, vitally important for understanding the nature and origins of sex-specific pathological conditions and for designing novel hormone-based therapeutic agents that will have optimal effectiveness in men or women. PMID:20392807

GPER Signaling in Spermatogenesis and Testicular Tumors.

PubMed

Chimento, Adele; Sirianni, Rosa; Casaburi, Ivan; Pezzi, Vincenzo

2014-01-01

Estrogens play important roles in the regulation of testis development and spermatogenesis. Moreover, several evidences suggest that estrogen signaling can be involved in testicular tumorigenesis. The physiological effects of estrogen are mediated by the classical nuclear estrogen receptors ESR1 and 2, which regulate both genomic and rapid signaling events. In the recent years, a member of the seven-transmembrane G protein-coupled receptor family, GPR30 (GPER), has been identified to promote estrogen action in target cells including testicular cells. Ours and other studies reported that GPER is expressed in normal germ cells (spermatogonia, spermatocytes, spermatids), somatic cells (Sertoli and Leydig cells), and it is also involved in mediating estrogen action during spermatogenesis and testis development. In addition, GPER seems to be involved in modulating estrogen-dependent testicular cancer cell growth. However, in this context, the effects of GPER stimulation on cell survival and proliferation appear to be cell type specific. This review summarizes the current knowledge on the functions regulated by estrogens and mediated by GPER in normal and tumor testicular cells.

GPER Signaling in Spermatogenesis and Testicular Tumors

PubMed Central

Chimento, Adele; Sirianni, Rosa; Casaburi, Ivan; Pezzi, Vincenzo

2014-01-01

Estrogens play important roles in the regulation of testis development and spermatogenesis. Moreover, several evidences suggest that estrogen signaling can be involved in testicular tumorigenesis. The physiological effects of estrogen are mediated by the classical nuclear estrogen receptors ESR1 and 2, which regulate both genomic and rapid signaling events. In the recent years, a member of the seven-transmembrane G protein-coupled receptor family, GPR30 (GPER), has been identified to promote estrogen action in target cells including testicular cells. Ours and other studies reported that GPER is expressed in normal germ cells (spermatogonia, spermatocytes, spermatids), somatic cells (Sertoli and Leydig cells), and it is also involved in mediating estrogen action during spermatogenesis and testis development. In addition, GPER seems to be involved in modulating estrogen-dependent testicular cancer cell growth. However, in this context, the effects of GPER stimulation on cell survival and proliferation appear to be cell type specific. This review summarizes the current knowledge on the functions regulated by estrogens and mediated by GPER in normal and tumor testicular cells. PMID:24639669

A Rapid, Extensive, and Transient Transcriptional Response to Estrogen Signaling in Breast Cancer Cells

PubMed Central

Hah, Nasun; Danko, Charles G.; Core, Leighton; Waterfall, Joshua J.; Siepel, Adam; Lis, John T.; Kraus, W. Lee

2011-01-01

Summary We report the immediate effects of estrogen signaling on the transcriptome of breast cancer cells using Global Run-On and sequencing (GRO-seq). The data were analyzed using a new bioinformatic approach that allowed us to identify transcripts directly from the GRO-seq data. We found that estrogen signaling directly regulates a strikingly large fraction of the transcriptome in a rapid, robust, and unexpectedly transient manner. In addition to protein coding genes, estrogen regulates the distribution and activity of all three RNA polymerases, and virtually every class of non-coding RNA that has been described to date. We also identified a large number of previously undetected estrogen-regulated intergenic transcripts, many of which are found proximal to estrogen receptor binding sites. Collectively, our results provide the most comprehensive measurement of the primary and immediate estrogen effects to date and a resource for understanding rapid signal-dependent transcription in other systems. PMID:21549415

Calmodulin Lobes Facilitate Dimerization and Activation of Estrogen Receptor-α*

PubMed Central

Li, Zhigang; Zhang, Yonghong; Hedman, Andrew C.; Ames, James B.

2017-01-01

Estrogen receptor α (ER-α) is a nuclear hormone receptor that controls selected genes, thereby regulating proliferation and differentiation of target tissues, such as breast. Gene expression controlled by ER-α is modulated by Ca2+ via calmodulin (CaM). Here we present the NMR structure of Ca2+-CaM bound to two molecules of ER-α (residues 287–305). The two lobes of CaM bind to the same site on two separate ER-α molecules (residues 292, 296, 299, 302, and 303), which explains why CaM binds two molecules of ER-α in a 1:2 complex and stabilizes ER-α dimerization. Exposed glutamate residues in CaM (Glu-11, Glu-14, Glu-84, and Glu-87) form salt bridges with key lysine residues in ER-α (Lys-299, Lys-302, and Lys-303), which is likely to prevent ubiquitination at these sites and inhibit degradation of ER-α. Transfection of cells with full-length CaM slightly increased the ability of estrogen to enhance transcriptional activation by ER-α of endogenous estrogen-responsive genes. By contrast, expression of either the N- or C-lobe of CaM abrogated estrogen-stimulated transcription of the estrogen responsive genes pS2 and progesterone receptor. These data suggest that CaM-induced dimerization of ER-α is required for estrogen-stimulated transcriptional activation by the receptor. In light of the critical role of ER-α in breast carcinoma, our data suggest that small molecules that selectively disrupt the interaction of ER-α with CaM may be useful in the therapy of breast carcinoma. PMID:28174300

Hpm of Estrogen Model on the Dynamics of Breast Cancer

NASA Astrophysics Data System (ADS)

Govindarajan, A.; Balamuralitharan, S.; Sundaresan, T.

2018-04-01

We enhance a deterministic mathematical model involving universal dynamics on breast cancer with immune response. This is population model so includes Normal cells class, Tumor cells, Immune cells and Estrogen. The eects regarding Estrogen are below incorporated in the model. The effects show to that amount the arrival of greater Estrogen increases the danger over growing breast cancer. Furthermore, approximate solution regarding nonlinear differential equations is arrived by Homotopy Perturbation Method (HPM). Hes HPM is good and correct technique after solve nonlinear differential equation directly. Approximate solution learnt with the support of that method is suitable same as like the actual results in accordance with this models.

Increased TET1 Expression in Inflammatory Microenvironment of Hyperinsulinemia Enhances the Response of Endometrial Cancer to Estrogen by Epigenetic Modulation of GPER

PubMed Central

Lv, Qiao-Ying; Xie, Bing-Ying; Yang, Bing-Yi; Ning, Cheng-Cheng; Shan, Wei-Wei; Gu, Chao; Luo, Xue-Zhen; Chen, Xiao-Jun; Zhang, Zhen-Bo; Feng, You-Ji

2017-01-01

Background: Insulin resistance (IR) has been well studied in the initiation and development of endometrial endometrioid carcinoma (EEC). As yet, it has been largely neglected for estrogen sensitivity in local endometrium in hyperinsulinemia-induced systemic microenvironment. The aim of this study was to investigate the role of insulin in regulating estrogen sensitivity and explore the potential mechanisms in insulin-driven inflammatory microenvironment. Methods: We first investigated the effect of insulin on estradiol-driven endometrial cancer cells proliferation in vitro to address the roles of insulin in modulating estrogen sensitivity. Then GPER, ERα and TET1 in EEC samples with or without insulin resistance were screened by immunohistochemistry to confirm whether insulin resistance regulates estrogen receptors. Further mechanism analysis was carried out to address whether TET1 was mediated epigenetic modulation of GPER in insulin-induced microenvironment. Results: Insulin enhanced estradiol-driven endometrial cancer cells proliferation by up-regulating G-protein-coupled estrogen receptor (GPER) expression, but not ERα or ERβ. Immunohistochemistry of EEC tissues showed that GPER expression was greatly increased in endometrial tissues from EEC subjects with insulin resistance and was positively correlated with Ten-eleven-translocation 1 (TET1) expression. Mechanistically, insulin up-regulates TET1 expression, and the latter, an important DNA hydroxymethylase, could up-regulate GPER expression through epigenetic modulation. Conclusion: This study identified TET1 as the upstream regulator of GPER expression and provides a possible mechanism that insulin-induced positive regulation of estrogen sensitivity in endometrial cancer cells. Increasing expression of GPER through TET1-mediated epigenetic modulation may emerge as the main regulator to enhance the response of endometrial cancer to estrogen in insulin-driven inflammatory microenvironment. PMID:28382153

Increased TET1 Expression in Inflammatory Microenvironment of Hyperinsulinemia Enhances the Response of Endometrial Cancer to Estrogen by Epigenetic Modulation of GPER.

PubMed

Lv, Qiao-Ying; Xie, Bing-Ying; Yang, Bing-Yi; Ning, Cheng-Cheng; Shan, Wei-Wei; Gu, Chao; Luo, Xue-Zhen; Chen, Xiao-Jun; Zhang, Zhen-Bo; Feng, You-Ji

2017-01-01

Background: Insulin resistance (IR) has been well studied in the initiation and development of endometrial endometrioid carcinoma (EEC). As yet, it has been largely neglected for estrogen sensitivity in local endometrium in hyperinsulinemia-induced systemic microenvironment. The aim of this study was to investigate the role of insulin in regulating estrogen sensitivity and explore the potential mechanisms in insulin-driven inflammatory microenvironment. Methods: We first investigated the effect of insulin on estradiol-driven endometrial cancer cells proliferation in vitro to address the roles of insulin in modulating estrogen sensitivity. Then GPER, ERα and TET1 in EEC samples with or without insulin resistance were screened by immunohistochemistry to confirm whether insulin resistance regulates estrogen receptors. Further mechanism analysis was carried out to address whether TET1 was mediated epigenetic modulation of GPER in insulin-induced microenvironment. Results: Insulin enhanced estradiol-driven endometrial cancer cells proliferation by up-regulating G-protein-coupled estrogen receptor (GPER) expression, but not ERα or ERβ. Immunohistochemistry of EEC tissues showed that GPER expression was greatly increased in endometrial tissues from EEC subjects with insulin resistance and was positively correlated with Ten-eleven-translocation 1 (TET1) expression. Mechanistically, insulin up-regulates TET1 expression, and the latter, an important DNA hydroxymethylase, could up-regulate GPER expression through epigenetic modulation. Conclusion: This study identified TET1 as the upstream regulator of GPER expression and provides a possible mechanism that insulin-induced positive regulation of estrogen sensitivity in endometrial cancer cells. Increasing expression of GPER through TET1-mediated epigenetic modulation may emerge as the main regulator to enhance the response of endometrial cancer to estrogen in insulin-driven inflammatory microenvironment.

Estrogen alters gonadal soma-derived factor (Gsdf)/Foxl2 expression levels in the testes associated with testis-ova differentiation in adult medaka, Oryzias latipes.

PubMed

Kobayashi, Tohru; Chiba, Ayaka; Sato, Tadashi; Myosho, Taijun; Yamamoto, Jun; Okamura, Tetsuro; Onishi, Yuta; Sakaizumi, Mitsuru; Hamaguchi, Satoshi; Iguchi, Taisen; Horie, Yoshifumi

2017-10-01

Testis-ova differentiation in sexually mature male medaka (Oryzias latipes) is easily induced by estrogenic chemicals, indicating that spermatogonia persist in sexual bipotentiality, even in mature testes in medaka. By contrast, the effects of estrogen on testicular somatic cells associated with testis-ova differentiation in medaka remain unclear. In this study, we focused on the dynamics of sex-related genes (Gsdf, Dmrt1, and Foxl2) expressed in Sertoli cells in the mature testes of adult medaka during estrogen-induced testis-ova differentiation. When mature male medaka were exposed to estradiol benzoate (EB; 800ng/L), testis-ova first appeared after EB treatment for 14days (observed as the first oocytes of the leptotene-zygotene stage). However, the testis remained structurally unchanged, even after EB treatment for 28days. Although Foxl2 is a female-specific sex gene, EB treatment for 7days induced Foxl2/FOXL2 expression in all Sertoli cell-enclosed spermatogonia before testis-ova first appeared; however, Foxl2 was not detected in somatic cells in control testes. Conversely, Sertoli-cell-specific Gsdf mRNA expression levels significantly decreased after EB treatment for 14days, and no changes were observed in DMRT1 localization following EB treatment, whereas Dmrt1 mRNA levels increased significantly. Furthermore, after EB exposure, FOXl2 and DMRT1 were co-localized in Sertoli cells during testis-ova differentiation, although FOXL2 localization was undetectable in Sertoli-cell-enclosed apoptotic testis-ova, whereas DMRT1 remained localized in Sertoli cells. These results indicated for the first time that based on the expression of female-specific sex genes, feminization of Sertoli cells precedes testis-ova differentiation induced by estrogen in mature testes in medaka; however, complete feminization of Sertoli cells was not induced in this study. Additionally, it is suggested strongly that Foxl2 and Gsdf expression constitute potential molecular markers for evaluating the effects of estrogenic chemicals on testicular somatic cells associated with estrogen-induced testis-ova differentiation in mature male medaka. Copyright © 2017 Elsevier B.V. All rights reserved.

ICI 182,780-regulated gene expression in DU145 prostate cancer cells is mediated by estrogen receptor-beta/NFkappaB crosstalk.

PubMed

Leung, Yuet-Kin; Gao, Ying; Lau, Kin-Mang; Zhang, Xiang; Ho, Shuk-Mei

2006-04-01

Estrogen receptor (ER)-beta is the predominant ER subtype in prostate cancer (PCa). We previously demonstrated that ICI 182,780 (ICI), but not estrogens, exerted dose-dependent growth inhibition on DU145 PCa cells by an ER-beta-mediated pathway. Transcriptional profiling detected a greater than three-fold upregulation of seven genes after a 12-hour exposure to 1 microM ICI. Semiquantitative reverse transcriptase polymerase chain reaction confirmed the upregulation of four genes by ICI: interleukin-12alpha chain, interleukin-8, embryonic growth/differentiation factor, and RYK tyrosine kinase. Treatment with an ER-beta antisense oligonucleotide reduced cellular ER-beta mRNA and induced loss of expression of these genes. Sequence analysis revealed the presence of consensus NFkappaB sites, but not estrogen-responsive elements, in promoters of all four genes. Reporter assay and chromatin immunoprecipitation experiments demonstrated that ICI-induced gene expression could be mediated by crosstalk between ER-beta and the NFkappaB signaling pathway, denoting a novel mechanism of ER-beta-mediated ICI action. Therefore, combined therapies targeting ER-beta and NFkappaB signaling may be synergistic as treatment for PCa.

ICI 182,780-Regulated Gene Expression in DU145 Prostate Cancer Cells Is Mediated by Estrogen Receptor-β/NFκB Crosstalk1

PubMed Central

Leung, Yuet-Kin; Gao, Ying; Lau, Kin-Mang; Zhang, Xiang; Ho, Shuk-Mei

2006-01-01

Abstract Estrogen receptor (ER)-β is the predominant ER subtype in prostate cancer (PCa). We previously demonstrated that ICI 182,780 (ICI), but not estrogens, exerted dose-dependent growth inhibition on DU145 PCa cells by an ER-β-mediated pathway. Transcriptional profiling detected a greater than three-fold upregulation of seven genes after a 12-hour exposure to 1 µM ICI. Semi-quantitative reverse transcriptase polymerase chain reaction confirmed the upregulation of four genes by ICI: interleukin-12α chain, interleukin-8, embryonic growth/differentiation factor, and RYK tyrosine kinase. Treatment with an ER-β antisense oligonucleotide reduced cellular ER-β mRNA and induced loss of expression of these genes. Sequence analysis revealed the presence of consensus NFκB sites, but not estrogen-responsive elements, in promoters of all four genes. Reporter assay and chromatin immunoprecipitation experiments demonstrated that ICI-induced gene expression could be mediated by crosstalk between ER-α and the NFκB signaling pathway, denoting a novel mechanism of ER-β-mediated ICI action. Therefore, combined therapies targeting ER-β and NFκB signaling may be synergistic as treatment for PCa. PMID:16756716

Lycium chinense Improves Post-Menopausal Obesity via Regulation of PPAR-γ and Estrogen Receptor-α/β Expressions.

PubMed

Kim, Mi Hye; Kim, Eun-Jung; Choi, You Yeon; Hong, Jongki; Yang, Woong Mo

2017-01-01

The fruit of Lycium chinense Miller (Solanaceae) is used as a functional food and a medicinal herb for treating many specific health concerns. Weight gain induced by estrogen deficiency is a problem for post-menopausal women around the globe. The present study investigates the effects of aqueous extract of L. chinense (LC) on post-menopausal obesity. Female C57BL/6 mice were ovariectomized and fed on high-fat diet (HFD) for 12 weeks to induce post-menopausal obesity. LC extract (1[Formula: see text]mg/kg and 10[Formula: see text]mg/kg) was orally administrated for 6 weeks with continuous HFD feeding. Ovarian adipose tissues and uterus were weighed. Serum triglyceride, cholesterol, LDL-cholesterol and fasting glucose levels were analyzed. The expressions of adipocyte-specific factors and estrogen receptors (ERs) were investigated. Additionally, lipid accumulation was confirmed in differentiated 3T3-L1 adipocytes. Increased body weight due to post-menopausal obesity was ameliorated about 14.7% and 17.76% by treatment of 1[Formula: see text]mg/kg and 10[Formula: see text]mg/kg LC, respectively. LC treatment reduced both of serum lipid and fasting blood glucose levels. Adipocyte hypertrophy and fatty liver were ameliorated in LC-treated groups. In LC-treated adipocyte cells, lipid accumulation was significantly inhibited. The expression of perilipin in adipose tissues was decreased by LC. In addition, expression of PPAR-[Formula: see text] protein was down-regulated in adipose tissues and differentiated adipocytes, while GLUT4 expression was increased in adipose tissues by LC treatment. Moreover, LC treatment up-regulated the expressions of ER-[Formula: see text]/[Formula: see text] accompanied with increased uterine weight. These results showed the ameliorative effects of LC on overweight after menopause. Post-menopausal obesity may be improved by LC treatment.

Vaginal Gene Expression During Treatment With Aromatase Inhibitors.

PubMed

Kallak, Theodora Kunovac; Baumgart, Juliane; Nilsson, Kerstin; Åkerud, Helena; Poromaa, Inger Sundström; Stavreus-Evers, Anneli

2015-12-01

Aromatase inhibitor (AI) treatment suppresses estrogen biosynthesis and causes genitourinary symptoms of menopause such as vaginal symptoms, ultimately affecting the quality of life for many postmenopausal women with breast cancer. Thus, the aim of this study was to examine vaginal gene expression in women during treatment with AIs compared with estrogen-treated women. The secondary aim was to study the presence and localization of vaginal aromatase. Vaginal biopsies were collected from postmenopausal women treated with AIs and from age-matched control women treated with vaginal estrogen therapy. Differential gene expression was studied with the Affymetrix Gene Chip Gene 1.0 ST Array (Affymetrix Inc, Santa Clara, CA) system, Ingenuity pathway analysis, quantitative real-time polymerase chain reaction, and immunohistochemistry. The expression of 279 genes differed between the 2 groups; AI-treated women had low expression of genes involved in cell differentiation, proliferation, and cell adhesion. Some differentially expressed genes were found to interact indirectly with the estrogen receptor alpha. In addition, aromatase protein staining was evident in the basal and the intermediate vaginal epithelium layers, and also in stromal cells with a slightly stronger staining intensity found in AI-treated women. In this study, we demonstrated that genes involved in cell differentiation, proliferation, and cell adhesion are differentially expressed in AI-treated women. The expression of vaginal aromatase suggests that this could be the result of local and systemic inhibition of aromatase. Our results emphasize the role of estrogen for vaginal cell differentiation and proliferation and future drug candidates should be aimed at improving cell differentiation and proliferation. Copyright © 2015 Elsevier Inc. All rights reserved.

Aroclor1254 interferes with estrogen receptor-mediated neuroprotection against beta-amyloid toxicity in cholinergic SN56 cells.

PubMed

Bang, Yeojin; Lim, Juhee; Kim, Sa Suk; Jeong, Hyung Min; Jung, Ki-Kyung; Kang, Il-Hyun; Lee, Kwang-Youl; Choi, Hyun Jin

2011-10-01

Because estrogen plays important neurotrophic and neuroprotective roles in the brain by activating estrogen receptors (ERs), disruption of normal estrogen signaling can leave neurons vulnerable to a variety of insults, including β-amyloid peptide (Aβ). Aroclor1254 (A1254) belongs to the endocrine-disrupting chemical (EDC) polychlorinated biphenyls and has anti-estrogenic properties. In the present study, we evaluated the effect of A1254 on the protective activity of estrogen against Aβ toxicity in differentiated cholinergic SN56 cells. Aged Aβ25-35 causes apoptotic cell death in differentiated SN56 cells, and the cytotoxic evidences are effectively rescued by estrogen. We found that A1254 abolishes the neuroprotective activity of estrogen against Aβ toxicity, and attenuates the suppressive effect of estrogen on Aβ-induced tau phosphorylation and JNK activation. The effects of A1254 on the neuroprotective effects of estrogen in Aβ toxicity are very similar to the effects of the estrogen receptor antagonist ICI182,780. Thus, exposure to EDCs that have anti-estrogenic activity might interfere with normal estrogen-activated neuroprotective signaling events and leave neurons more vulnerable to dangerous stimuli. Our present results provide new understanding of the mechanisms contributing to the harmful effects of EDCs on the function and viability of neurons, and the possible relevance of EDCs in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease. Copyright © 2011 Elsevier B.V. All rights reserved.

FIELD APPLICATION OF A SHEEPSHEAD MINNOW ESTROGEN-RESPONSIVE CDNA MACROARRAY

EPA Science Inventory

Preliminary experiments with the sheepshead minnow (Cyprinodon variegatus) have revealed at least 30 genes which are up-regulated by estrogen treatments. Identical patterns of gene up-regulation have been observed for the native ligand estradiol and the pharmaceutical estrogens e...

The Role of Hypothalamic Estrogen Receptors in Metabolic Regulation

PubMed Central

Frank, Aaron; Brown, Lynda M.; Clegg, Deborah J.

2014-01-01

Estrogens regulate key features of metabolism, including food intake, body weight, energy expenditure, insulin sensitivity, leptin sensitivity, and body fat distribution. There are two ”classical“ estrogen receptors (ERs): estrogen receptor alpha (ERS1) and estrogen receptor beta (ERS2). Human and murine data indicate ERS1 contributes to metabolic regulation more so than ESR2. For example, there are human inactivating mutations of ERS1 which recapitulate aspects of the metabolic syndrome in both men and women. Much of our understanding of the metabolic roles of ERS1 was initially uncovered in estrogen receptor α-null mice (ERS1−/−); these mice display aspects of the metabolic syndrome, including increased body weight, increased visceral fat deposition and dysregulated glucose intolerance. Recent data further implicate ERS1 in specific tissues and neuronal populations as being critical for regulating food intake, energy expenditure, body fat distribution and adipose tissue function. This review will focus predominantly on the role of hypothalamic ERs and their critical role in regulating all aspects of energy homeostasis and metabolism. PMID:24882636

The role of hypothalamic estrogen receptors in metabolic regulation.

PubMed

Frank, Aaron; Brown, Lynda M; Clegg, Deborah J

2014-10-01

Estrogens regulate key features of metabolism, including food intake, body weight, energy expenditure, insulin sensitivity, leptin sensitivity, and body fat distribution. There are two 'classical' estrogen receptors (ERs): estrogen receptor alpha (ERS1) and estrogen receptor beta (ERS2). Human and murine data indicate ERS1 contributes to metabolic regulation more so than ESR2. For example, there are human inactivating mutations of ERS1 which recapitulate aspects of the metabolic syndrome in both men and women. Much of our understanding of the metabolic roles of ERS1 was initially uncovered in estrogen receptor α-null mice (ERS1(-/-)); these mice display aspects of the metabolic syndrome, including increased body weight, increased visceral fat deposition and dysregulated glucose intolerance. Recent data further implicate ERS1 in specific tissues and neuronal populations as being critical for regulating food intake, energy expenditure, body fat distribution and adipose tissue function. This review will focus predominantly on the role of hypothalamic ERs and their critical role in regulating all aspects of energy homeostasis and metabolism. Copyright © 2014 Elsevier Inc. All rights reserved.

Research Resource: Aorta- and Liver-Specific ERα-Binding Patterns and Gene Regulation by Estrogen

PubMed Central

Gordon, Francesca K.; Vallaster, Caroline S.; Westerling, Thomas; Iyer, Lakshmanan K.; Brown, Myles

2014-01-01

Estrogen has vascular protective effects in premenopausal women and in women younger than 60 years who are receiving hormone replacement therapy. However, estrogen also increases the risks of breast and uterine cancers and of venous thromboses linked to up-regulation of coagulation factors in the liver. In mouse models, the vasculoprotective effects of estrogen are mediated by the estrogen receptor α (ERα) transcription factor. Here, through next-generation sequencing approaches, we show that almost all of the genes regulated by 17β-estradiol (E2) differ between mouse aorta and mouse liver, ex vivo, and that this difference is associated with a distinct genomewide distribution of ERα on chromatin. Bioinformatic analysis of E2-regulated promoters and ERα binding site sequences identify several transcription factors that may determine the tissue specificity of ERα binding and E2-regulated genes, including the enrichment of NF-κB, AML1, and AP1 sites in the promoters of E2 down-regulated inflammatory genes in aorta but not liver. The possible vascular-specific functions of these factors suggest ways in which the protective effects of estrogen could be promoted in the vasculature without incurring negative effects in other tissues. PMID:24992180

Assessment of the potential activity of major dietary compounds as selective estrogen receptor modulators in two distinct cell models for proliferation and differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lecomte, Sylvain; Lelong, Marie; Bourgine, Gaëlle

Estrogen receptors (ERs) α and β are distributed in most tissues of women and men. ERs are bound by estradiol (E2), a natural hormone, and mediate the pleiotropic and tissue-specific effects of E2, such as proliferation of breast epithelial cells or protection and differentiation of neuronal cells. Numerous environmental molecules, called endocrine disrupting compounds, also interact with ERs. Phytoestrogens belong to this large family and are considered potent therapeutic molecules that act through their selective estrogen receptor modulator (SERM) activity. Using breast cancer cell lines as a model of estrogen-dependent proliferation and a stably ER-expressing PC12 cell line as amore » model of neuronal differentiating cells, we studied the SERM activity of major dietary compounds, such as apigenin, liquiritigenin, daidzein, genistein, coumestrol, resveratrol and zearalenone. The ability of these compounds to induce ER-transactivation and breast cancer cell proliferation and enhance Nerve Growth Factor (NGF) -induced neuritogenesis was assessed. Surprisingly, although all compounds were able to activate the ER through an estrogen responsive element reporter gene, they showed differential activity toward proliferation or differentiation. Apigenin and resveratrol showed a partial or no proliferative effect on breast cancer cells but fully contributed to the neuritogenesis effect of NGF. However, daidzein and zearalenone showed full effects on cellular proliferation but did not induce cellular differentiation. In summary, our results suggest that the therapeutic potential of phytoestrogens can diverge depending on the molecule and the phenotype considered. Hence, apigenin and resveratrol might be used in the development of therapeutics for breast cancer and brain diseases. - Highlights: • SERM activity of dietary compounds on proliferation and differentiation is studied. • All the dietary compounds tested transactivate estrogen receptors. • Apigenin and resveratrol could be good candidates for future therapeutics. • Daidzein and zearalenone are to be avoided to maintain human health.« less

Regulation of Estrogen Receptor α Expression in the Hypothalamus by Sex Steroids: Implication in the Regulation of Energy Homeostasis.

PubMed

Liu, Xian; Shi, Haifei

2015-01-01

Sex differences exist in the complex regulation of energy homeostasis that utilizes central and peripheral systems. It is widely accepted that sex steroids, especially estrogens, are important physiological and pathological components in this sex-specific regulation. Estrogens exert their biological functions via estrogen receptors (ERs). ERα, a classic nuclear receptor, contributes to metabolic regulation and sexual behavior more than other ER subtypes. Physiological and molecular studies have identified multiple ERα-rich nuclei in the hypothalamus of the central nervous system (CNS) as sites of actions that mediate effects of estrogens. Much of our understanding of ERα regulation has been obtained using transgenic models such as ERα global or nuclei-specific knockout mice. A fundamental question concerning how ERα is regulated in wild-type animals, including humans, in response to alterations in steroid hormone levels, due to experimental manipulation (i.e., castration and hormone replacement) or physiological stages (i.e., puberty, pregnancy, and menopause), lacks consistent answers. This review discusses how different sex hormones affect ERα expression in the hypothalamus. This information will contribute to the knowledge of estrogen action in the CNS, further our understanding of discrepancies in correlation of altered sex hormone levels with metabolic disturbances when comparing both sexes, and improve health issues in postmenopausal women.

Integrative Analysis Reveals Regulatory Programs in Endometriosis

PubMed Central

Yang, Huan; Kang, Kai; Cheng, Chao; Mamillapalli, Ramanaiah; Taylor, Hugh S.

2015-01-01

Endometriosis is a common gynecological disease found in approximately 10% of reproductive-age women. Gene expression analysis has been performed to explore alterations in gene expression associated with endometriosis; however, the underlying transcription factors (TFs) governing such expression changes have not been investigated in a systematic way. In this study, we propose a method to integrate gene expression with TF binding data and protein–protein interactions to construct an integrated regulatory network (IRN) for endometriosis. The IRN has shown that the most regulated gene in endometriosis is RUNX1, which is targeted by 14 of 26 TFs also involved in endometriosis. Using 2 published cohorts, GSE7305 (Hover, n = 20) and GSE7307 (Roth, n = 36) from the Gene Expression Omnibus database, we identified a network of TFs, which bind to target genes that are differentially expressed in endometriosis. Enrichment analysis based on the hypergeometric distribution allowed us to predict the TFs involved in endometriosis (n = 40). This included known TFs such as androgen receptor (AR) and critical factors in the pathology of endometriosis, estrogen receptor α, and estrogen receptor β. We also identified several new ones from which we selected FOXA2 and TFAP2C, and their regulation was confirmed by quantitative real-time polymerase chain reaction and immunohistochemistry (IHC). Further, our analysis revealed that the function of AR and p53 in endometriosis is regulated by posttranscriptional changes and not by differential gene expression. Our integrative analysis provides new insights into the regulatory programs involved in endometriosis. PMID:26134036

Modulation of HIV replication in monocyte derived macrophages (MDM) by steroid hormones.

PubMed

Devadas, Krishnakumar; Biswas, Santanu; Ragupathy, Viswanath; Lee, Sherwin; Dayton, Andrew; Hewlett, Indira

2018-01-01

Significant sex specific differences in the progression of HIV/AIDS have been reported. Several studies have implicated steroid hormones in regulating host factor expression and modulating HIV transmission and replication. However, the exact mechanism exerted by steroid hormones estrogen and progesterone in the regulation of HIV-1 replication is still unclear. Results from the current study indicated a dose dependent down regulation of HIV-1 replication in monocyte derived macrophages pre-treated with high concentrations of estrogen or progesterone. To elucidate the molecular mechanisms associated with the down regulation of HIV-1 replication by estrogen and progesterone we used PCR arrays to analyze the expression profile of host genes involved in antiviral responses. Several chemokines, cytokines, transcription factors, interferon stimulated genes and genes involved in type-1 interferon signaling were down regulated in cells infected with HIV-1 pre-treated with high concentrations of estrogen or progesterone compared to untreated HIV-1 infected cells or HIV-1 infected cells treated with low concentrations of estrogen or progesterone. The down regulation of CXCL9, CXCL10 and CXCL11 chemokines and IL-1β, IL-6 cytokines in response to high concentrations of estrogen and progesterone pre-treatment in HIV-1 infected cells was confirmed at the protein level by quantitating chemokine and cytokine concentrations in the culture supernatant. These results demonstrate that a potent anti-inflammatory response is mediated by pre-treatment with high concentrations of estrogen and progesterone. Thus, our study suggests a strong correlation between the down-modulation of anti-viral and pro-inflammatory responses mediated by estrogen and progesterone pre-treatment and the down regulation of HIV-1 replication. These findings may be relevant to clinical observations of sex specific differences in patient populations and point to the need for further investigation.

Differential effects of Glycyrrhiza species on genotoxic estrogen metabolism: licochalcone A downregulates P450 1B1 whereas isoliquiritigenin stimulates

PubMed Central

Dunlap, Tareisha L.; Wang, Shuai; Simmler, Charlotte; Chen, Shao-Nong; Pauli, Guido F.; Dietz, Birgit M.; Bolton, Judy L.

2015-01-01

Estrogen chemical carcinogenesis involves 4-hydroxylation of estrone/estradiol (E1/E2) by P450 1B1, generating catechol and quinone genotoxic metabolites that cause DNA mutations and initiate/promote breast cancer. Inflammation enhances this effect by up-regulating P450 1B1. The present study tested the three authenticated medicinal species of licorice, [Glycyrrhiza glabra (GG), G. uralensis (GU), and G. inflata (GI)], used by women as dietary supplements, for their anti-inflammatory activities and their ability to modulate estrogen metabolism. The pure compounds, liquiritigenin (LigF), its chalcone isomer isoliquiritigenin (LigC), and the GI specific licochalcone A (LicA) were also tested. The licorice extracts and compounds were evaluated for anti-inflammatory activity by measuring inhibition of iNOS activity in macrophage cells: GI > GG > GU and LigC ≅ LicA > LigF. The Michael acceptor chalcone LicA, is likely responsible for the anti-inflammatory activity of GI. A sensitive LC-MS/MS assay was employed to quantify estrogen metabolism by measuring 2-MeOE1 as non-toxic and 4-MeOE1 as genotoxic biomarkers in the non-tumorigenic human mammary epithelial cell line, MCF-10A. GG, GU, and LigC increased 4-MeOE1, whereas GI and LicA inhibited 2- and 4-MeOE1 levels. GG, GU (5 μg/mL), and LigC (1 μM) also enhanced P450 1B1 expression and activities, which was further increased by inflammatory cytokines (TNF-α and IFN-γ). LicA (1 μM, 10 μM) decreased cytokine- and TCDD-induced, P450 1B1 gene expression and TCDD-induced xenobiotic response element luciferase reporter (IC50=12.3 μM), suggesting an antagonistic effect on the aryl hydrocarbon receptor, which regulates P450 1B1. Similarly, GI (5 μg/mL) reduced cytokine- and TCDD-induced P450 1B1 gene expression. Collectively, these data suggest that of the three licorice species that are used in botanical supplements, GI represents the most promising chemopreventive licorice extract for women’s health. Additionally, the differential effects of the Glycyrrhiza species on estrogen metabolism emphasize the importance of standardization of botanical supplements to species-specific bioactive compounds. PMID:26134484

Post-translational regulation of endothelial nitric oxide synthase (eNOS) by estrogens in the rat vagina.

PubMed

Musicki, Biljana; Liu, Tongyun; Strong, Travis D; Lagoda, Gwen A; Bivalacqua, Trinity J; Burnett, Arthur L

2010-05-01

Estrogens control vaginal blood flow during female sexual arousal mostly through nitric oxide (NO). Although vascular effects of estrogens are attributed to an increase in endothelial NO production, the mechanisms of endothelial NO synthase (eNOS) regulation by estrogens in the vagina are largely unknown. Our hypothesis was that estrogens regulate eNOS post-translationally in the vagina, providing a mechanism to affect NO bioavailability without changes in eNOS protein expression. We measured eNOS phosphorylation and eNOS interaction with caveolin-1 and heat shock protein 90 (HSP90) in the distal and proximal vagina of female rats at diestrus, 7 days after ovariectomy and 2 days after replacement of ovariectomized rats with estradiol-17beta (15 microg). Molecular mechanisms of eNOS regulation by estrogen in the rat vagina. We localized phospho-eNOS (Ser-1177) immunohistochemically to the endothelium lining blood vessels and vaginal sinusoids. Estrogen withdrawal decreased phosphorylation of eNOS on its positive regulatory site (Ser-1177) and increased eNOS binding to its negative regulator caveolin-1 (without affecting eNOS/HSP90 interaction), and they were both normalized by estradiol replacement. Protein expressions of phosphorylated Akt (protein kinase B) and extracellular signal-regulated protein kinase 1/2 (ERK1/2) were not affected by estrogen status, suggesting that the effect of estrogens on eNOS (Ser-1177) phosphorylation was not mediated by activated AKT or ERK1/2. eNOS phosphorylation on its negative regulatory site (Ser-114) was increased in the vagina by estrogen withdrawal and normalized by estradiol replacement, implying that the maintenance of low phosphorylation of eNOS on this site by estradiol may limit eNOS interaction with caveolin-1 and preserve the enzyme's activity. Total eNOS, inducible NOS, caveolin-1, and HSP90 protein expressions were not affected by ovariectomy or estradiol replacement in the distal or proximal vagina. These results define novel estrogen signaling mechanisms in the vagina which involve eNOS phosphorylation and eNOS-caveolin-1 interaction.

Post-translational Regulation of Endothelial Nitric Oxide Synthase (eNOS) by Estrogens in the Rat Vagina

PubMed Central

Musicki, Biljana; Liu, Tongyun; Strong, Travis D.; Lagoda, Gwen A.; Bivalacqua, Trinity J.; Burnett, Arthur L.

2010-01-01

Introduction Estrogens control vaginal blood flow during female sexual arousal mostly through nitric oxide (NO). Although vascular effects of estrogens are attributed to an increase in endothelial NO production, the mechanisms of endothelial NO synthase (eNOS) regulation by estrogens in the vagina are largely unknown. Aims Our hypothesis was that estrogens regulate eNOS post-translationally in the vagina, providing a mechanism to affect NO bioavailability without changes in eNOS protein expression. Methods We measured eNOS phosphorylation and eNOS interaction with caveolin-1 and heat shock protein 90 (HSP90) in the distal and proximal vagina of female rats at diestrus, 7 days after ovariectomy and 2 days after replacement of ovariectomized rats with estradiol-17β (15 μg). Main Outcome Measures Molecular mechanisms of eNOS regulation by estrogen in the rat vagina. Results We localized phospho-eNOS (Ser-1177) immunohistochemically to the endothelium lining blood vessels and vaginal sinusoids. Estrogen withdrawal decreased phosphorylation of eNOS on its positive regulatory site (Ser-1177) and increased eNOS binding to its negative regulator caveolin-1 (without affecting eNOS/HSP90 interaction), and they were both normalized by estradiol replacement. Protein expressions of phosphorylated Akt (protein kinase B) and extracellular signal-regulated protein kinase 1/2 (ERK1/2) were not affected by estrogen status, suggesting that the effect of estrogens on eNOS (Ser-1177) phosphorylation was not mediated by activated AKT or ERK1/2. eNOS phosphorylation on its negative regulatory site (Ser-114) was increased in the vagina by estrogen withdrawal and normalized by estradiol replacement, implying that the maintenance of low phosphorylation of eNOS on this site by estradiol may limit eNOS interaction with caveolin-1 and preserve the enzyme's activity. Total eNOS, inducible NOS, caveolin-1, and HSP90 protein expressions were not affected by ovariectomy or estradiol replacement in the distal or proximal vagina. Conclusions These results define novel estrogen signaling mechanisms in the vagina which involve eNOS phosphorylation and eNOS-caveolin-1 interaction. PMID:20233295

A GATA-2/estrogen receptor chimera functions as a ligand-dependent negative regulator of self-renewal

PubMed Central

Heyworth, Clare; Gale, Karin; Dexter, Michael; May, Gillian; Enver, Tariq

1999-01-01

The transcription factor GATA-2 is expressed in hematopoietic stem and progenitor cells and is functionally implicated in their survival and proliferation. We have used estrogen and tamoxifen-inducible forms of GATA-2 to modulate the levels of GATA-2 in the IL-3-dependent multipotential hematopoietic progenitor cell model FDCP mix. Ligand-dependent induction of exogenous GATA-2 activity did not rescue cells deprived of IL-3 from apoptosis. However, induction of GATA-2 activity in cells cultured in IL-3 blocked factor-dependent self-renewal but not factor-dependent survival: Cells undergo cell cycle arrest and cease proliferating but do not apoptose. This was accompanied by differentiation down the monocytic and granulocytic pathways. Differentiation occurred in the presence of IL-3 and did not require addition of exogenous differentiation growth factors such as G-CSF or GM-CSF normally required to induce granulomonocytic differentiation of FDCP-mix cells. Conversely, EPO-dependent erythroid differentiation was inhibited by GATA-2 activation. These biological effects were obtained with levels of exogenous GATA-2 representing less than twofold increases over endogenous GATA-2 levels and were not observed in cells overexpressing GATA-1/ER. Similar effects on proliferation and differentiation were also observed in primary progenitor cells, freshly isolated from murine bone marrow and transduced with a GATA-2/ER-containing retrovirus. Taken together, these data suggest that threshold activities of GATA-2 in hematopoietic progenitor cells are a critical determinant in influencing self-renewal versus differentiation outcomes. PMID:10421636

Environmental Estrogens Differentially Engage the Histone Methyltransferase EZH2 to Increase Risk of Uterine Tumorigenesis

PubMed Central

Greathouse, K. Leigh; Bredfeldt, Tiffany; Everitt, Jeffrey I.; Lin, Kevin; Berry, Tia; Kannan, Kurunthachalam; Mittelstadt, Megan L.; Ho, Shuk-mei; Walker, Cheryl L.

2013-01-01

Environmental exposures during sensitive windows of development can reprogram normal physiological responses and alter disease susceptibility later in life in a process known as developmental reprogramming. For example, exposure to the xenoestrogen diethylstilbestrol (DES) during reproductive tract development can reprogram estrogen-responsive gene expression in the myometrium, resulting in hyper-responsiveness to hormone in the adult uterus and promotion of hormone-dependent uterine leiomyoma. We show here that the environmental estrogens genistein (GEN), a soy phytoestrogen, and the plasticizer bisphenol A (BPA), differ in their pattern of developmental reprogramming and promotion of tumorigenesis (leiomyomas) in the uterus. While both GEN and BPA induce genomic estrogen receptor (ER) signaling in the developing uterus, only GEN induced PI3K/AKT non-genomic ER signaling to the histone methyltransferase Enhancer of Zeste homolog 2 (EZH2). As a result, this “pre-genomic” signaling phosphorylates and represses EZH2, and reduces levels of H3K27 repressive mark in chromatin. Furthermore, only GEN caused estrogen-responsive genes in the adult myometrium to become hyper-responsive to hormone; estrogen-responsive genes were repressed in BPA exposed uteri. Importantly, this pattern of EZH2 engagement to decrease versus increase H3K27 methylation correlated with the effect of these xenoestrogens on tumorigenesis. Developmental reprogramming by GEN promoted development of uterine leiomyomas, increasing tumor incidence and multiplicity, while BPA did not. These data demonstrate that environmental estrogens have distinct non-genomic effects in the developing uterus that determines their ability to engage the epigenetic regulator EZH2, decrease levels of the repressive epigenetic histone H3K27 methyl mark in chromatin during developmental reprogramming, and promote uterine tumorigenesis. PMID:22504913

Estrogenic activity of natural and synthetic estrogens in human breast cancer cells in culture.

PubMed Central

Zava, D T; Blen, M; Duwe, G

1997-01-01

We investigated the estrogenic activity of various environmental pollutants (xenobiotics), in particular the xenoestrogen o,p-DDT, and compared their effects with those of endogenous estrogens, phytoestrogens, and mycoestrogens on estrogen receptor binding capacity, induction of estrogen end products, and activation of cell proliferation in estrogen-sensitive human breast cancer cells in monolayer culture. We also quantified the levels of phytoestrogens in extracts of some common foods, herbs, and spices and in human saliva following consumption of a high phytoestrogen food source (soy milk) to compare phytoestrogen abundance and bioavailability relative to the reported xenoestrogen burden in humans. Results show that natural endogenous estrogens, phytoestrogens, mycoestrogens, and xenoestrogens bind estrogen receptor (ER) in intact cells, but demonstrate marked differences in their ability to induce end products of estrogen action and to regulate cell proliferation. All of the different classes of estrogens stimulated cell proliferation at concentrations that half-saturated ER, but only some classes were able to induce estrogen-regulated end products. Genistein, a common phytoestrogen found in soy foods, differed from the xenoestrogen DDT in its effects on cell proliferation and ability to induce estrogen-regulated end products. Moreover, we found that many of the foods, herbs, and spices commonly consumed by humans contain significant amounts of phytoestrogens, and consumption of soy milk, a phytoestrogen-rich food, markedly increases the levels of phytoestrogens in saliva. In conclusion, our in vitro results predict that a diet high in phytoestrogens would significantly reduce the binding of weak xenoestrogens to ER in target tissues in vivo. PMID:9168008

Cancer genes induced by malathion and parathion in the presence of estrogen in breast cells.

PubMed

Calaf, G M; Roy, D

2008-02-01

The identification of genes involved in the process of neoplastic transformation is essential for analyzing the progression of breast cancer when induced by endogenous and exogenous agents, among which are the estrogens and the organophosphorous pesticides, respectively. It is important to consider the impact of such substances when they are present in combination. In vitro experimental models are needed in order to understand breast carcinogenesis. The aim of this work was to examine the effect of 17beta estradiol (estrogen) combined with either malathion or parathion on the transformation of human breast epithelial cells in vitro. Results showed that estrogen combined with either malathion or parathion altered cell proliferation and induced cell transformation as well as exhibited significant invasive capabilities as compared to the control MCF-10F cell line. Several genes were up-regulated by the effect of all of the treatments, such as the cyclins, cyclin D1 and cyclin-dependent kinase 4, IGFBP3 and IGFBP5, and keratin 18. The c-Ha-ras oncogene was up-regulated by the effect of malathion alone and with the combination of estrogen and either malathion or parathion. The DVL1 gene was up-regulated only with malathion alone and the combination of parathion with estrogen. Expression of the HSP 27, MCM2 and TP53 inducible protein 3 genes was up-regulated with malathion alone and with the combination of estrogen and either malathion or parathion while TP53 (Li-Fraumeni syndrome) was up-regulated by estrogen alone and malathion alone. Thus, we suggest that pesticides and estrogens affect human breast cells inducing molecular changes indicative of transformation.

Nuclear receptor co-regulator Kruppel-like factor 9 and prohibitin 2 expression in estrogen-induced epithelial cell proliferation in the mouse uterus

USDA-ARS?s Scientific Manuscript database

Estrogen, acting through its cognate receptor estrogen receptor-' (ESR1), is a critical regulator of uterine endometrial epithelial proliferation. Although the dynamic communication between endometrial stromal (ST) and epithelial cells is considered to be an important component in this process, key ...

Arctigenin functions as a selective agonist of estrogen receptor β to restrict mTORC1 activation and consequent Th17 differentiation.

PubMed

Wu, Xin; Tong, Bei; Yang, Yan; Luo, Jinque; Yuan, Xusheng; Wei, Zhifeng; Yue, Mengfan; Xia, Yufeng; Dai, Yue

2016-12-20

Arctigenin was previously proven to inhibit Th17 cell differentiation and thereby attenuate colitis in mice by down-regulating the activation of mechanistic target of rapamycin complex 1 (mTORC1). The present study was performed to address its underlying mechanism in view of estrogen receptor (ER). The specific antagonist PHTPP or siRNA of ERβ largely diminished the inhibitory effect of arctigenin on the mTORC1 activation in T cell lines and primary CD4+ T cells under Th17-polarization condition, suggesting that arctigenin functioned in an ERβ-dependent manner. Moreover, arctigenin was recognized to be an agonist of ERβ, which could bind to ERβ with a moderate affinity, promote dissociation of ERβ/HSP90 complex and nuclear translocation and phosphorylation of ERβ, and increase the transcription activity. Following activation of ERβ, arctigenin inhibited the activity of mTORC1 by disruption of ERβ-raptor-mTOR complex assembly. Deficiency of ERβ markedly abolished arctigenin-mediated inhibition of Th17 cell differentiation. In colitis mice, the activation of ERβ, inhibition of mTORC1 activation and Th17 response by arctigenin were abolished by PHTPP treatment. In conclusion, ERβ might be the target protein of arctigenin responsible for inhibition of mTORC1 activation and resultant prevention of Th17 cell differentiation and colitis development.

Arctigenin functions as a selective agonist of estrogen receptor β to restrict mTORC1 activation and consequent Th17 differentiation

PubMed Central

Wu, Xin; Tong, Bei; Yang, Yan; Luo, Jinque; Yuan, Xusheng; Wei, Zhifeng; Yue, Mengfan; Xia, Yufeng; Dai, Yue

2016-01-01

Arctigenin was previously proven to inhibit Th17 cell differentiation and thereby attenuate colitis in mice by down-regulating the activation of mechanistic target of rapamycin complex 1 (mTORC1). The present study was performed to address its underlying mechanism in view of estrogen receptor (ER). The specific antagonist PHTPP or siRNA of ERβ largely diminished the inhibitory effect of arctigenin on the mTORC1 activation in T cell lines and primary CD4+ T cells under Th17-polarization condition, suggesting that arctigenin functioned in an ERβ-dependent manner. Moreover, arctigenin was recognized to be an agonist of ERβ, which could bind to ERβ with a moderate affinity, promote dissociation of ERβ/HSP90 complex and nuclear translocation and phosphorylation of ERβ, and increase the transcription activity. Following activation of ERβ, arctigenin inhibited the activity of mTORC1 by disruption of ERβ-raptor-mTOR complex assembly. Deficiency of ERβ markedly abolished arctigenin-mediated inhibition of Th17 cell differentiation. In colitis mice, the activation of ERβ, inhibition of mTORC1 activation and Th17 response by arctigenin were abolished by PHTPP treatment. In conclusion, ERβ might be the target protein of arctigenin responsible for inhibition of mTORC1 activation and resultant prevention of Th17 cell differentiation and colitis development. PMID:27863380

Environmental signaling: from environmental estrogens to endocrine-disrupting chemicals and beyond.

PubMed

McLachlan, J A

2016-07-01

The landmark report (Herbst et al. 1971) linking prenatal treatment with a synthetic estrogen, diethylstilbestrol (DES), to cancer at puberty in women whose mothers took the drug while pregnant ushered in an era of research on delayed effects of such exposures on functional outcomes in offspring. An animal model developed in our laboratory at the National Institute of Environmental Health Sciences confirmed that DES was the carcinogen and exposure to DES caused, as well, functional alterations in the reproductive, endocrine, and immune systems of male and female mice treated in utero. DES was also being used in agriculture and we discovered, at the first meeting on Estrogens in the Environment in 1979 (Estrogens in the Environment, 1980), that many environmental contaminants were also estrogenic. Many laboratories sought to discern the basis for estrogenicity in environmental chemicals and to discover other hormonally active xenobiotics. Our laboratory elucidated how DES and other estrogenic compounds worked by altering differentiation through epigenetic gene imprinting, helping explain the transgenerational effects found in mice and humans. At the Wingspread Conference on the Human-Wildlife Connection in 1991 (Advances in Modern Environmental Toxicology, 1992), we learned that environmental disruption of the endocrine system occurred in many species and phyla, and the term endocrine disruption was introduced. Further findings of transgenerational effects of environmental agents that mimicked or blocked various reproductive hormones and the ubiquity of environmental signals, such as bisphenol A increased concern for human and ecological health. Scientists began to look at other endocrine system aspects, such as cardiovascular and immune function, and other nuclear receptors, with important observations regarding obesity and metabolism. Laboratories, such as ours, are now using stem cells to try to understand the mechanisms by which various environmental signals alter cell differentiation. Since 2010, research has shown that trauma and other behavioral inputs can function as 'environmental signals,' can be encoded in gene regulation networks in a variety of cells and organs, and can be passed on to subsequent generations. So now we come full circle: environmental chemicals mimic hormones or other metabolic signaling molecules and now behavioral experience can be transduced into chemical signals that also modify gene expression. © 2016 American Society of Andrology and European Academy of Andrology.

Minireview: The Year in Review of Estrogen Regulation of Metabolism

PubMed Central

2012-01-01

Gonadal steroids are critical regulators of physiology, yet we approach physiology and science with the simplest perspective/model, the male one. Female models of whole animal physiology are complex to study and, therefore, are often not used in research. Estrogens are one of the sex hormones that we know are important for both men and women. Estrogens regulate key features of metabolism such as food intake, body weight, glucose homeostasis/insulin sensitivity, body fat distribution, lipolysis/lipogenesis, inflammation, locomotor activity, energy expenditure, reproduction, and cognition. Furthermore, estrogens have multiple sites of action including some unexpected ones, which was demonstrated elegantly through a series of papers this year. PMID:23051593

Sex-Based Differences in Skeletal Muscle Kinetics and Fiber-Type Composition

PubMed Central

Haizlip, K. M.; Harrison, B. C.

2015-01-01

Previous studies have identified over 3,000 genes that are differentially expressed in male and female skeletal muscle. Here, we review the sex-based differences in skeletal muscle fiber composition, myosin heavy chain expression, contractile function, and the regulation of these physiological differences by thyroid hormone, estrogen, and testosterone. The findings presented lay the basis for the continued work needed to fully understand the skeletal muscle differences between males and females. PMID:25559153

Estrogen and the Dietary Phytoestrogen Resveratrol as Regulators of the Rho GTPase Rac in Breast Cancer Metastasis

DTIC Science & Technology

2011-09-01

cancer patient, express breast differentiation-specific proteins , and secrete milk lipids [45]. Therefore, the simplest conclusion is that MDA-MB-435...chromosomes; expresses milk proteins and lipids; and when transfected with the nm23 metastasis suppressor gene, MDA-MB-435 cells show the morphologic... proteins and secrete milk lipids [44]. Since the patient had no evidence of melanoma but was diagnosed with only a breast carcinoma; and, since

ESR1 single nucleotide polymorphisms predict breast cancer susceptibility in the central European Caucasian population.

PubMed

Lipphardt, Mark F; Deryal, Mustafa; Ong, Mei Fang; Schmidt, Werner; Mahlknecht, Ulrich

2013-01-01

Estrogen and progesterone hormones are key regulators of a wide variety of biological processes. In addition to their influence on reproduction, cell differentiation and apoptosis, they affect inflammatory response, cell metabolism and most importantly, they regulate physiological breast tissue proliferation and differentiation as well as the development and progression of breast cancer. In order to assess whether genetic variants in the steroid hormone receptor gene ESR1 (estrogen receptor alpha) had an effect on sporadic breast cancer susceptibility, we assessed 7 ESR1 single nucleotide polymorphisms (SNPs) for associations with breast cancer susceptibility and clinical parameters in 221 breast cancer patients and 221 controls, respectively. We identified ESR1 intron SNP +2464 C/T (rs3020314) and ESR1 intron SNP -4576 A/C (rs1514348) to correlate with breast cancer susceptibility and progesterone receptor expression status. Patients genotyped CT for ESR1 intron SNP +2464 (rs3020314) (p ≤ 0.045) or genotyped AC for ESR1 intron SNP -4576 (rs1514348) (p ≤ 0.000026) were identified to carry a significant risk as to the development of breast cancer in the Central European Caucasian population (both together: p ≤ 0.000488). Our study could confirm previous associations and revealed new associations of SNP rs1514348 with susceptibility to breast cancer and clinical outcome, which might be used as new additional SNP markers.

Repression of Osteoblast Maturation by ERRα Accounts for Bone Loss Induced by Estrogen Deficiency

PubMed Central

Gallet, Marlène; Saïdi, Soraya; Haÿ, Eric; Photsavang, Johann; Marty, Caroline; Sailland, Juliette; Carnesecchi, Julie; Tribollet, Violaine; Barenton, Bruno; Forcet, Christelle; Birling, Marie-Christine; Sorg, Tania; Chassande, Olivier; Cohen-Solal, Martine; Vanacker, Jean-Marc

2013-01-01

ERRα is an orphan member of the nuclear receptor family, the complete inactivation of which confers resistance to bone loss induced by ageing and estrogen withdrawal to female mice in correlation with increased bone formation in vivo. Furthermore ERRα negatively regulates the commitment of mesenchymal cells to the osteoblast lineage ex vivo as well as later steps of osteoblast maturation. We searched to determine whether the activities of ERRα on osteoblast maturation are responsible for one or both types of in vivo induced bone loss. To this end we have generated conditional knock out mice in which the receptor is normally present during early osteoblast differentiation but inactivated upon osteoblast maturation. Bone ageing in these animals was similar to that observed for control animals. In contrast conditional ERRαKO mice were completely resistant to bone loss induced by ovariectomy. We conclude that the late (maturation), but not early (commitment), negative effects of ERRα on the osteoblast lineage contribute to the reduced bone mineral density observed upon estrogen deficiency. PMID:23359549

Estrogen and phenol red free medium for osteoblast culture: study of the mineralization ability.

PubMed

de Faria, A N; Zancanela, D C; Ramos, A P; Torqueti, M R; Ciancaglini, P

2016-08-01

To design an estrogen and phenol red free medium for cell culture and check its effectiveness and safety on osteoblast growth it is necessary to maintain the estrogen receptors free for tests. For this purpose, we tested some modifications of the traditional culture media: estrogen depleted fetal bovine serum; estrogen charcoal stripped fetal bovine serum and phenol red free α-MEM. The aim of this work is to examine the effects of its depletion in the proliferation, differentiation, and toxicity of mesenchymal stromal cells differentiated into osteoblasts to obtain an effective interference free culture medium for in vitro studies, focused on non-previously studied estrogen receptors. We performed viability tests using the following techniques: MTT, alkaline phosphatase specific activity, formation of mineralized matrix by Alizarin technique and analysis of SEM/EDX of mineralized nodules. The results showed that the culture media with estrogen free α-MEM + phenol red free α-MEM did not impact viability, alkaline phosphatase activity and mineralization of the osteoblasts culture compared to control. In addition, its nodules possess Ca/P ratio similar to hydroxyapatite nodules on the 14th and 21st day. In conclusion, the modified culture medium with phenol red free α-MEM with estrogen depleted fetal bovine serum can be safely used in experiments where the estrogen receptors need to be free.

Determination of the Role of Estrogen Receptors and Estrogen Regulated Genes in B Cell Autoreactivity

DTIC Science & Technology

2008-07-01

signaling strength was a consequence of enhanced expression of CD22 , an inhibitory regulator of the BCR. We now know this conjecture is incorrect as...estrogen causes an upregulation of CD22 in ERα-/- and ERβ-/- mice (Fig 4a) but there is no associated estrogen-induced reduction of BCR signalling... CD22 expression (Fig 4b). We believe the discrepancy between the analysis of genetically manipulated mice given estradiol and wildtype mice given

Morphological Analysis of the Axonal Projections of EGFP-Labeled Esr1-Expressing Neurons in Transgenic Female Medaka.

PubMed

Zempo, Buntaro; Karigo, Tomomi; Kanda, Shinji; Akazome, Yasuhisa; Oka, Yoshitaka

2018-02-01

Some hypothalamic neurons expressing estrogen receptor α (Esr1) are thought to transmit a gonadal estrogen feedback signal to gonadotropin-releasing hormone 1 (GnRH1) neurons, which is the final common pathway for feedback regulation of reproductive functions. Moreover, estrogen-sensitive neurons are suggested to control sexual behaviors in coordination with reproduction. In mammals, hypothalamic estrogen-sensitive neurons release the peptide kisspeptin and regulate GnRH1 neurons. However, a growing body of evidence in nonmammalian species casts doubt on the regulation of GnRH1 neurons by kisspeptin neurons. As a step toward understanding how estrogen regulates neuronal circuits for reproduction and sex behavior in vertebrates in general, we generated a transgenic (Tg) medaka that expresses enhanced green fluorescent protein (EGFP) specifically in esr1-expressing neurons (esr1 neurons) and analyzed their axonal projections. We found that esr1 neurons in the preoptic area (POA) project to the gnrh1 neurons. We also demonstrated by transcriptome and histological analyses that these esr1 neurons are glutamatergic or γ-aminobutyric acidergic (GABAergic) but not kisspeptinergic. We therefore suggest that glutamatergic and GABAergic esr1 neurons in the POA regulate gnrh1 neurons. This hypothesis is consistent with previous studies in mice that found that glutamatergic and GABAergic transmission is critical for estrogen-dependent changes in GnRH1 neuron firing. Thus, we propose that this neuronal circuit may provide an evolutionarily conserved mechanism for regulation of reproduction. In addition, we showed that telencephalic esr1 neurons project to medulla, which may control sexual behavior. Moreover, we found that some POA-esr1 neurons coexpress progesterone receptors. These neurons may form the neuronal circuits that regulate reproduction and sex behavior in response to the serum estrogen/progesterone. Copyright © 2018 Endocrine Society.

Dynamics of hepatic and intestinal cholesterol and bile acid pathways: The impact of the animal model of estrogen deficiency and exercise training

PubMed Central

Lavoie, Jean-Marc

2016-01-01

Plasma cholesterol level is determined by a complex dynamics that involves transport lipoproteins which levels are tightly dependent on how the liver and the intestine regulate cholesterol and biliary acid metabolism. Regulation of cholesterol and biliary acids by the liver and the intestine is in turn coupled to a large array of enzymes and transporters that largely influence the inflow and the outflow of cholesterol and biliary acids through these organs. The activity of the key regulators of cholesterol and biliary acids may be influenced by several external factors such as pharmacological drugs and the nutritional status. In recent years, more information has been gathered about the impact of estrogens on regulation of cholesterol in the body. Exposure to high levels of estrogens has been reported to promote cholesterol gallstone formation and women are twice as likely as men to develop cholesterol gallstones. The impact of estrogen withdrawal, such as experienced by menopausal women, is therefore of importance and more information on how the absence of estrogens influence cholesterol regulation is started to come out, especially through the use of animal models. An interesting alternative to metabolic deterioration due to estrogen deficiency is exercise training. The present review is intended to summarize the present information that links key regulators of cholesterol and biliary acid pathways in liver and intestine to the absence of estrogens in an animal model and to discuss the potential role of exercise training as an alternative. PMID:27621762

Extent of Vascular Remodeling Is Dependent on the Balance Between Estrogen Receptor α and G-Protein-Coupled Estrogen Receptor.

PubMed

Gros, Robert; Hussain, Yasin; Chorazyczewski, Jozef; Pickering, J Geoffrey; Ding, Qingming; Feldman, Ross D

2016-11-01

Estrogens are important regulators of cardiovascular function. Some of estrogen's cardiovascular effects are mediated by a G-protein-coupled receptor mechanism, namely, G-protein-coupled estrogen receptor (GPER). Estradiol-mediated regulation of vascular cell programmed cell death reflects the balance of the opposing actions of GPER versus estrogen receptor α (ERα). However, the significance of these opposing actions on the regulation of vascular smooth muscle cell proliferation or migration in vitro is unclear, and the significance in vivo is unknown. To determine the effects of GPER activation in vitro, we studied rat aortic vascular smooth muscle cells maintained in primary culture. GPER was reintroduced using adenoviral gene transfer. Both estradiol and G1, a GPER agonist, inhibited both proliferation and cell migration effects that were blocked by the GPER antagonist, G15. To determine the importance of the GPER-ERα balance in regulating vascular remodeling in a rat model of carotid ligation, we studied the effects of upregulation of GPER expression versus downregulation of ERα. Reintroduction of GPER significantly attenuated the extent of medial hypertrophy and attenuated the extent of CD45 labeling. Downregulation of ERα expression comparably attenuated the extent of medial hypertrophy and inflammation after carotid ligation. These studies demonstrate that the balance between GPER and ERα regulates vascular remodeling. Receptor-specific modulation of estrogen's effects may be an important new approach in modifying vascular remodeling in both acute settings like vascular injury and perhaps in longer term regulation like in hypertension. © 2016 American Heart Association, Inc.

Estrogen receptors in neuropeptide Y neurons: at the crossroads of feeding and reproduction.

PubMed

Acosta-Martinez, Maricedes; Horton, Teresa; Levine, Jon E

2007-03-01

Hypothalamic neuropeptide Y (NPY) neurons function as physiological integrators in at least two different neuroendocrine systems - one governing feeding and the other controlling reproduction. Estrogen might modulate both systems by regulating NPY gene expression; it might reduce food intake by suppressing NPY expression, and evoke reproductive hormone surges by stimulating it. How can estrogen exert opposing effects in an ostensibly homogeneous NPY neuronal population? Recent work with immortalized NPY-producing cells suggests that the ratio of estrogen receptor alpha:estrogen receptor beta can determine the direction and temporal pattern of transcriptional responses to estrogen. Because this ratio might itself be physiologically regulated, these findings provide one explanation for multiple neuropeptidergic responses to a single steroid hormone.

Differential ability of formononetin to stimulate proliferation of endothelial cells and breast cancer cells via a feedback loop involving MicroRNA-375, RASD1, and ERα.

PubMed

Chen, Jian; Zhang, Xing; Wang, Yong; Ye, Yu; Huang, Zhaoquan

2018-05-02

For postmenopausal cardiovascular disease, long-term estrogen therapy may increase the risk of breast cancer. To reduce this risk, estrogen may be replaced with the phytoestrogen formononetin, but how formononetin acts on vascular endothelial cells (ECs) and breast cancer cells is unclear. Here, we show that low concentrations of formononetin induced proliferation and inhibited apoptosis more strongly in cultured human umbilical vein endothelial cells (HUVECs) than in breast cancer cells expressing estrogen receptor α (ERα) (MCF-7, BT474) or not (MDA-MB-231), and that this differential stimulation was associated with miR-375 up-regulation in HUVECs. For the first time, we demonstrate the presence of a feedback loop involving miR-375, ras dexamethasone-induced 1 (RASD1), and ERα in normal HUVECs, and we show that formononetin stimulated this feedback loop in HUVECs but not in MCF-7 or BT474 cells. In all three cell lines, formononetin increased Akt phosphorylation and Bcl-2 expression. Inhibiting miR-375 blocked these changes and increased proliferation in HUVECs, but not in MCF-7 or BT474 cells. In ovariectomized rats, formononetin increased uterine weight and caused similar changes in levels of miR-375, RASD1, ERα, and Bcl-2 in aortic ECs as in cultured HUVECs. In mice bearing MCF-7 xenografts, tumor growth was stimulated by 17β-estradiol but not by formononetin. These results suggest selective action of formononetin in ECs (proliferation stimulation and apoptosis inhibition) relative to breast cancer cells, possibly via a feedback loop involving miR-375, RASD1, and ERα. This differential effect may explain why formononetin may not increase the risk of postmenopausal breast cancer. © 2018 Wiley Periodicals, Inc.

Two novel GPER agonists induce gene expression changes and growth effects in cancer cells.

PubMed

Lappano, R; Rosano, C; Santolla, M F; Pupo, M; De Francesco, E M; De Marco, P; Ponassi, M; Spallarossa, A; Ranise, A; Maggiolini, M

2012-06-01

Although the action of estrogens has been traditionally explained by the binding to and transactivation of the nuclear estrogen receptor (ER)α and ERβ, recently the G protein-coupled receptor GPR30/GPER has been involved in the rapid estrogen signaling. We investigated the ability of two original molecules, which were named GPER-L1 and GPERL2, to bind to and activate the GPER transduction pathway in cancer cells. Competition assays, docking simulations, transfection experiments, real-time PCR, immunoblotting, gene silencing technology and growth assays were performed to ascertain the selective action of GPER-L1 and GPER-L2 in activating the GPER-mediated signaling. Both compounds, which did not show any ability to bind to and activate the classical ERs, were able to bind to GPER and to trigger the rapid activation of the GPER/EGFR/ERK transduction pathway which led to the up-regulation of GPER-target genes. Notably, GPER-L1 and GPER-L2 induced the proliferation of SkBr3 breast and Ishikawa endometrial cancer cells at nM concentrations through GPER, hence providing further evidence on their capability to elicit relevant biological responses mediated by GPER. The identification and characterization of these novel compounds as selective GPER agonists represent a valuable tool to further dissect the pharmacology of this novel estrogen receptor and to better differentiate the specific functions elicited by each estrogen receptor subtype in cancer cells.

Sequential changes in the expression of Wnt- and Notch-related genes in the vagina and uterus of ovariectomized mice after estrogen exposure.

PubMed

Nakamura, Takeshi; Miyagawa, Shinichi; Katsu, Yoshinao; Sato, Tomomi; Iguchi, Taisen; Ohta, Yasuhiko

2012-01-01

Estrogen regulates morphological changes in reproductive organs, such as the vagina and uterus, during the estrous cycles in mice. Estrogen depletion by ovariectomy in adults results in atrophy accompanied by apoptosis in vaginal and uterine cells, while estrogen treatment following ovariectomy elicits cell proliferation in both organs. Sequential changes in mRNA expression of wingless-related MMTV integration site (Wnt) and Notch signaling genes were analyzed in the vagina and uterus of ovariectomized adult mice after a single injection of 17β-estradiol to provide understanding over the molecular basis of differences in response to estrogen in these organs. We found estrogen-dependent up-regulation of Wnt4, Wnt5a and p21 and down-regulation of Wnt11, hairy/enhancer-of-split related with YRPW motif-1 (Hey1) and delta-like 4 (Dll4) in the vagina, and up-regulation of Wnt4, Wnt5a, Hey1, Heyl, Dll1, p21 and p53 and down-regulation of Wnt11, Hey2 and Dll4 in the uterus. The expression of Wnt4, Hey1, Hey2, Heyl, Dll1 and p53 showed different patterns after the estrogen injection. Expression patterns for Wnt5a, Wnt11, Dll4 and p21 in the vagina and uterus were similar, suggesting that these genes are involved in the proliferation of cells in both those organs in mice.

Mechanism of estrogen activation of c-myc oncogene expression.

PubMed

Dubik, D; Shiu, R P

1992-08-01

The estrogen receptor complex is a known trans-acting factor that regulates transcription of specific genes through an interaction with a specific estrogen-responsive cis-acting element (ERE). In previous studies we have shown that in estrogen-responsive human breast cancer cells estrogen rapidly activates c-myc expression. This activated expression occurs through enhanced transcription and does not require the synthesis of new protein intermediates; therefore, an ERE is present in the human c-myc gene regulatory region. To localize the ERE, constructs containing varying lengths of the c-myc 5'-flanking region ranging from -2327 to +25 (relative to the P1 promoter) placed adjacent to the chloramphenicol acetyl transferase reporter gene (CAT) were prepared. They were used in transient transfection studies in MCF-7 and HeLa cells co-transfected with an estrogen receptor expression vector. These studies reveal that all constructs containing the P2 promoter region exhibited estrogen-regulated CAT expression and that a 116-bp region upstream and encompassing the P2 TATA box is necessary for this activity. Analysis of this 116-bp region failed to identify a cis-acting element with sequences resembling the consensus ERE; however, co-transfection studies with mutant estrogen receptor expression vectors showed that the DNA-binding domain of the receptor is essential for estrogen-regulated CAT gene expression. We have also observed that anti-estrogen receptor complexes can weakly trans-activate from this 116-bp region but fail to do so from the ERE-containing ApoVLDLII-CAT construct. To explain these results we propose a new mechanism of estrogen trans-activation in the c-myc gene promoter.

Expression and regulation of estrogen-converting enzymes in ectopic human endometrial tissue.

PubMed

Fechner, Sabine; Husen, Bettina; Thole, Hubert; Schmidt, Markus; Gashaw, Isabella; Kimmig, Rainer; Winterhager, Elke; Grümmer, Ruth

2007-10-01

To investigate the regulation of estrogen-converting enzymes in human ectopic endometrial tissue. Animal study. Academic medical center. Sixty female nude mice with implanted human endometrial tissue. Twenty-two premenopausal women undergoing endometrial biopsy or hysterectomy. Human endometrial tissue was implanted into the peritoneal cavity of nude mice, and the effect of therapeutic drugs on transcription of steroid receptors and estrogen-converting enzymes was analyzed. Transcript levels of steroid hormone receptors, 17beta-hydroxysteroid dehydrogenase type 1 and 2, aromatase, and steroid sulfatase as well as proliferation rate were analyzed in the human ectopic endometrial tissue. Steroid receptors and estrogen-converting enzymes were expressed in the ectopic human endometrial fragments. Application of medroxyprogesterone acetate, dydrogesterone, danazol, and the aromatase inhibitor finrozole significantly inhibited aromatase transcription. In addition, danazol caused a significant decrease in transcription of steroid sulfatase, and finrozole, of 17beta-hydroxysteroid dehydrogenase type 1 in parallel to a decrease in proliferation rate in the ectopic human endometrial tissue. Pharmacological regulation of transcription of estrogen-converting enzymes in human endometrium cultured in nude mice may help to develop new therapeutic concepts based on local regulation of estrogen metabolism in endometriosis.

Actions of placental and fetal adrenal steroid hormones in primate pregnancy.

PubMed

Pepe, G J; Albrecht, E D

1995-10-01

It is clear that steroid hormones of placental and fetal adrenal origin have critically important roles in regulating key physiological events essential to the maintenance of pregnancy and development of the fetus for extrauterine life. Thus, progesterone has suppressive actions on lymphocyte proliferation and activity and on the immune system to prevent rejection of the developing fetus and placenta (see Fig. 9). Progesterone also suppresses the calcium-calmodulin-MLCK system and thus activity of uterine smooth muscle, thereby promoting myometrial quiescence to ensure the maintenance of pregnancy. Estrogen enhances uteroplacental blood flow and possibly placental neovascularization to provide optimal gas exchange and the nutrients required for the rapidly developing fetus and placenta. In turn, estrogen has specific stimulatory effects on the receptor-mediated uptake of LDL by, and P-450scc activity within, syncytiotrophoblasts, thus promoting the biosynthesis of progesterone. Moreover, there is an estrogen-dependent developmental regulation of expression of the LDL receptor and NAD-dependent 11 beta-HSD in the placenta, processes reflecting functional/biochemical differentiation of the trophoblast cells with advancing gestation. The increase in 11 beta-HSD causes a change in transplacental corticosteroid metabolism, which results in activation of the HPAA in the fetus. As a result of this cascade of events, there is an increase in expression of pituitary POMC/ACTH and key enzymes, e.g. 3 beta-HSD and P-450 17 alpha-hydroxylase, important for de novo cortisol formation by, and consequently maturation of, the fetal adrenal gland. In turn, cortisol has well defined actions on surfactant biosynthesis and consequently fetal lung maturation, as well as effects on placental CRH/POMC release, which may be important to the initiation of labor. At midgestation, estrogen also selectively feeds back on the fetal adrenal to suppress DHA and maintain physiologically normal levels of estrogen. Preparation of the breast for lactation and nourishment of the newborn appears to involve a multifactorial system of regulation that includes estrogen. It is apparent, therefore, that autocrine/paracrine, as well as endocrine, systems of regulation are operative within the fetoplacental unit during primate pregnancy. A major goal of this review has been to illustrate the critically close functional communication existing between the developing placenta and fetus in the biosynthesis and the actions of steroid hormones during primate pregnancy. The functional interaction of the human fetal adrenal and placenta with respect to the biosynthesis of estrogen was demonstrated many years ago. However, the recent studies presented in this review show that the endocrine interaction between the fetus and placenta is more extensive, involving complex physiological regulatory mechanisms. Thus, as illustrated in Fig. 9, estrogen, acting via its receptor within the placenta and other reproductive tissues, orchestrates the dynamic interchange between the placenta and fetus responsible for the developmental regulation of the biosynthesis of the various steroid and peptide hormones and their receptors necessary for the maintenance of pregnancy and development of a live newborn. It would appear, therefore, that the immediate and long range challenges in this area of reproductive endocrinology are to employ in vitro molecular and in vivo experimental approaches simultaneously to elucidate the nature of these complex interactions and define the cellular and molecular mechanisms underlying these important regulatory events.

Melatonin affects the dynamic steady-state equilibrium of estrogen sulfates in human umbilical vein endothelial cells by regulating the balance between estrogen sulfatase and sulfotransferase.

PubMed

González, Alicia; Martínez-Campa, Carlos; Alonso-González, Carolina; Cos, Samuel

2015-12-01

Melatonin is known to reduce the growth of endocrine-responsive breast cancers by interacting with estrogen signaling pathways. Estrogens play an important role in breast cancer, but also in various types of tissues, including vascular tissue. Estrogen sulfatase (STS) converts inactive estrogen sulfates into active estrogens, whereas estrogen sulfotransferase (EST) sulfonates estrogens to estrogen sulfates. Therefore, STS and EST are considered to be involved in the regulation of local estrogen levels in hormone‑dependent tumors and in non-pathologic tissues, such as those of the vascular system. Estrogens have a major impact on the vasculature, influencing vascular function, the expression of adhesion proteins, angiogenesis and the inflammatory state. In this study, we investigated the status of STS and EST in human umbilical vein endothelial cells (HUVECs) and the modulatory effects of melatonin. Both STS and EST were highly expressed in the HUVECs. The enzymatic activity correlated with the expression levels in these cells. Our findings also demonstrated that melatonin, at physiological concentrations, modulated the synthesis and transformation of biologically active estrogens in HUVECs through the inhibition of STS activity and expression, and the stimulation of EST activity and expression. Since melatonin decreased the STS levels and increased the EST levels, it modified the dynamic steady‑state equilibrium of estrogen sulfates by increasing the inactive estrogen levels and decreasing the active estrogen levels. Therefore, melatonin may modulate the known different biological actions of estrogens in endothelial cells, as well as in estrogen-dependent tumors and non-pathologic tissues.

Characterization of Gonadal Transcriptomes from Nile Tilapia (Oreochromis niloticus) Reveals Differentially Expressed Genes

PubMed Central

Sun, Yunlv; Yang, Shijie; Li, Minghui; Zeng, Sheng; Huang, Baofeng; Wang, Deshou

2013-01-01

Four pairs of XX and XY gonads from Nile tilapia were sequenced at four developmental stages, 5, 30, 90, and 180 days after hatching (dah) using Illumina HiseqTM technology. This produced 28 Gb sequences, which were mapped to 21,334 genes. Of these, 259 genes were found to be specifically expressed in XY gonads, and 69 were found to be specific to XX gonads. Totally, 187 XX- and 1,358 XY-enhanced genes were identified, and 2,978 genes were found to be co-expressed in XX and XY gonads. Almost all steroidogenic enzymes, including cyp19a1a, were up-regulated in XX gonads at 5 dah; but in XY gonads these enzymes, including cyp11b2, were significantly up-regulated at 90 dah, indicating that, at a time critical to sex determination, the XX fish produced estrogen and the XY fish did not produce androgens. The most pronounced expression of steroidogenic enzyme genes was observed at 30 and 90 dah for XX and XY gonads, corresponding to the initiation of germ cell meiosis in the female and male gonads, respectively. Both estrogen and androgen receptors were found to be expressed in XX gonads, but only estrogen receptors were expressed in XY gonads at 5 dah. This could explain why exogenous steroid treatment induced XX and XY sex reversal. The XX-enhanced expression of cyp19a1a and cyp19a1b at all stages suggests an important role for estrogen in female sex determination and maintenance of phenotypic sex. This work is the largest collection of gonadal transcriptome data in tilapia and lays the foundation for future studies into the molecular mechanisms of sex determination and maintenance of phenotypic sex in non-model teleosts. PMID:23658843

Differential expression of caveolin-1 in human myometrial and uterine leiomyoma smooth muscle.

PubMed

Zhou, Yu; Ren, Yuanyuan; Cui, Lihua; Li, Zongjin; Zhu, Yingjun; Lin, Wanjun; Wang, Yuebing

2014-11-01

Uterine leiomyomas, the most common neoplasms of the female genital tract, are benign tumors of the uterus arising from the smooth muscle cells (SMCs) of the myometrium with an involvement of estrogen. Caveolin-1 (Cav-1), a major protein component in caveolae membrane lipid rafts, is down-regulated in several estrogen-related cancer cells, and overexpression of Cav-1 inhibits proliferation of cancer cells and vascular SMCs as well. Therefore, we hypothesize that Cav-1 is down-regulated in human uterine leiomyoma. Western blot using tissues from clinical patients showed that Cav-1 expression was significantly lower or undetectable in uterine leiomyoma compared with their matched myometrium (P < .001). This finding was confirmed by immunohistochemistry and confocal microscopy. The cav-1 mRNA level in uterine leiomyomas was also significantly lower as detected by reverse transcription-quantitative polymerase chain reaction analysis (P = .001). To further study the underlying mechanism, we performed primary cell culture, and found that the expression of Cav-1 remained low in cultured leiomyoma SMCs (P = .009). Serum withdrawal did not change Cav-1 expression in leiomyoma SMCs, but increased expression in myometrial SMCs (P = .006). 17-β estradiol inhibited the expression of Cav-1 protein (P = .047) and mRNA (P = .007) in leiomyoma SMCs, whereas it stimulated expression in myometrial SMCs (P = .043). 17-β estradiol, although activating the mitogen-activated protein kinase pathway in both SMCs, did not stimulate their proliferation. We conclude that human uterine leiomyomas in vitro express low levels of Cav-1, which may result from estrogen inhibition. This effect of estrogen may contribute to the pathogenesis of uterine leiomyoma. Further studies in vivo are needed to verify these results. Copyright © 2014 Elsevier Inc. All rights reserved.

Gene expression fingerprints of largemouth bass (Micropterus salmoides) exposed to pulp and paper mill effluents.

PubMed

Denslow, Nancy D; Kocerha, Jannet; Sepúlveda, Maria S; Gross, Timothy; Holm, Stewart E

2004-08-18

Effluents from pulp and paper mills that historically have used elemental chlorine in the bleaching process have been implicated in inhibiting reproduction in fish. Compounds with estrogenic and androgenic binding affinities have been found in these effluents, suggesting that the impairment of reproduction is through an endocrine-related mode of action. To date, a great deal of attention has been paid to phytoestrogens and resin acids that are present in mill process streams as a result of pulping trees. Estrogen and estrogen mimics interact directly with the estrogen receptor and have near immediate effects on gene transcription by turning on the expression of a unique set of genes. Using differential display (DD) RT-PCR, we examined changes in gene expression induced by exposure to paper mill effluents. Largemouth bass were exposed to 0, 10, 20, 40, and 80% paper mill effluent concentrations in large flow-through tanks for varied periods of time including 7, 28 or 56 days. Plasma hormone levels in males and females and plasma vitellogenin (Vtg) in females decreased with dose and time. Measurements of changes in gene expression using DD RT-PCR suggest that the gene expression patterns of male fish do not change much with exposure, except for the induction of a few genes including CYP 1A, a protein that is induced through the action of the Ah receptor in response to dioxin and similar polyaromatic hydrocarbons. However, in the case of females, exposure to these effluents resulted in an up-regulation of CYP 1A that was accompanied by a generalized down-regulation of genes normally expressed during the reproductive season. These antiestrogenic changes are in agreement with previous studies in bass exposed to these effluents, and could result in decreased reproductive success in affected populations.

Analysis of a cis-Acting Element Involved in Regulation by Estrogen of Human Angiotensinogen Gene Expression.

PubMed

Zhao, Yan-Yan; Sun, Kai-Lai; Ashok, Kumar

1998-01-01

The work was aimed to identify the estrogen responsive element in the human angiotensinogen gene. The nucleotide sequence between the transcription initiation site and TATA box in angiotensinogen gene promoter was found to be strongly homologous with the consensus estrogen responsive element. This sequence was confirmed as the estrogen responsive element (HAG ERE) by electrophoretic mobility shift assay. The recombinant expression vectors were constructed in which chloramphenicol acetyltransferase (CAT) reporter gene was driven by angiotensinogen core promoter with HAG ERE of by TK core promoter with multiplied HAG ERE, and were used in cotransfection with the human estrogen receptor expression vector into HepG(2) cells; CAT assays showed an increase of the CAT activity on 17beta-estradiol treatment in those transfectants. These results suggest that the human angiotensinogen gene is transcriptionally up-regulated by estrogen through the estrogen responsive element near TATA box of the promoter.

Aberrant estrogen regulation of PEMT results in choline deficiency-associated liver dysfunction.

PubMed

Resseguie, Mary E; da Costa, Kerry-Ann; Galanko, Joseph A; Patel, Mukund; Davis, Ian J; Zeisel, Steven H

2011-01-14

When dietary choline is restricted, most men and postmenopausal women develop multiorgan dysfunction marked by hepatic steatosis (choline deficiency syndrome (CDS)). However, a significant subset of premenopausal women is protected from CDS. Because hepatic PEMT (phosphatidylethanolamine N-methyltransferase) catalyzes de novo biosynthesis of choline and this gene is under estrogenic control, we hypothesized that there are SNPs in PEMT that disrupt the hormonal regulation of PEMT and thereby put women at risk for CDS. In this study, we performed transcript-specific gene expression analysis, which revealed that estrogen regulates PEMT in an isoform-specific fashion. Locus-wide SNP analysis identified a risk-associated haplotype that was selectively associated with loss of hormonal activation. Chromatin immunoprecipitation, analyzed by locus-wide microarray studies, comprehensively identified regions of estrogen receptor binding in PEMT. The polymorphism (rs12325817) most highly linked with the development of CDS (p < 0.00006) was located within 1 kb of the critical estrogen response element. The risk allele failed to bind either the estrogen receptor or the pioneer factor FOXA1. These data demonstrate that allele-specific ablation of estrogen receptor-DNA interaction in the PEMT locus prevents hormone-inducible PEMT expression, conferring risk of CDS in women.

Neonatal estrogenic exposure suppresses PTEN-related endometrial carcinogenesis in recombinant mice.

PubMed

Begum, Monjura; Tashiro, Hironori; Katabuchi, Hidetaka; Suzuki, Akira; Kurman, Robert J; Okamura, Hitoshi

2006-03-01

Human endometrial carcinomas, as well as complex atypical hyperplasias (CAH), are estrogen related and frequently have mutations in the PTEN gene. However, the mutual contribution of estrogen and PTEN mutations to endometrial carcinogenesis in vivo is unknown. To address this issue, we investigated whether neonatal estrogenic treatments augment the incidence of CAH and carcinomas in murine PTEN (mPTEN) heterozygous (+/-) mutant mice, an animal model for endometrial carcinoma. Low doses of diethylstilbestrol (1 ng/g/day), genistein (50 microg/g/day) in phytoestrogens, estriol (E(3)) (4 microg/g/day), and vehicle (ethanol and corn oil) were administered subcutaneously daily to neonatal pups from the 1st to 5th day after birth. At 52 weeks of age, the morphological changes in the endometrium, and uterine expression of Hoxa 10 and Hoxa 11, were evaluated. These Hoxa genes are abdominal B-type homeobox genes, which normally regulate differentiation of the Müllerian duct. The incidence of CAH and adenocarcinomas of the endometrium was significantly decreased by the neonatal estrogenic treatments in the mPTEN+/- mice. Coincidentally, all treatments significantly decreased the stromal cell density, and CAH and adenocarcinomas rarely developed in the epithelium adjacent to the affected endometrial stroma. Moreover, the uterine expression of Hoxa 10 in mice with neonatal genistein and E(3) treatments, and that of Hoxa 11 in mice with all treatments, was significantly lower when compared with vehicle alone. Taken together, neonatal estrogenic exposure induced stromal atrophy and/or hyalinization accompanied by repressed expression of Hoxa 10 and Hoxa 11, and exerted an inhibitory effect on PTEN-related tumorigenesis. These findings provide new insight into the interaction between endometrial epithelium and stroma in endometrial carcinogenesis in vivo.

Expression and localization of aromatase P450AROM, estrogen receptor-α, and estrogen receptor-β in the developing fetal bovine frontal cortex.

PubMed

Peruffo, A; Giacomello, M; Montelli, S; Corain, L; Cozzi, B

2011-06-01

The enzyme aromatase (P450(AROM)) converts testosterone (T) into 17-β estradiol (E(2)) and is crucial for the control of development of the central nervous system during ontogenesis. The effects of E(2) in various brain areas are mediated by the estrogen receptor alpha (ER-α) and the estrogen receptor beta (ER-β). During fetal development, steroids are responsible for the sexual differentiation of the hypothalamus. Estrogens are also able to exert effects in other brain areas of the fetus including the frontal cortex, where they act through estrogen receptors (ERs) modulating cognitive function and affective behaviors. In this study we have determined the expression profiles of P450(AROM) and ERs in the fetal bovine frontal cortex by quantitative Real-Time PCR (qRT-PCR) throughout the prenatal development. The data show that the patterns of expression of both ERs are strongly correlated during pregnancy and increase in the last stage of gestation. On the contrary, the expression of P450(AROM) has no correlation with ERs expression and is not developmentally regulated. Moreover, we performed immunochemical studies showing that fetal neurons express P450(AROM) and the ERs. P450(AROM) is localized in the cytoplasm and only seldom present in the fine extensions of the cells; ER-α is detected predominantly in the soma whereas ER-β is only present in the nucleus of a few cells. This study provides new data on the development of the frontal cortex in a long gestation mammal with a large convoluted brain. Copyright © 2011 Elsevier Inc. All rights reserved.

Quantitative RT-PCR analysis of estrogen receptor gene expression in laser microdissected prostate cancer tissue.

PubMed

Walton, Thomas J; Li, Geng; McCulloch, Thomas A; Seth, Rashmi; Powe, Desmond G; Bishop, Michael C; Rees, Robert C

2009-06-01

Real-time quantitative RT-PCR analysis of laser microdissected tissue is considered the most accurate technique for determining tissue gene expression. The discovery of estrogen receptor beta (ERbeta) has focussed renewed interest on the role of estrogen receptors in prostate cancer, yet few studies have utilized the technique to analyze estrogen receptor gene expression in prostate cancer. Fresh tissue was obtained from 11 radical prostatectomy specimens and from 6 patients with benign prostate hyperplasia. Pure populations of benign and malignant prostate epithelium were laser microdissected, followed by RNA isolation and electrophoresis. Quantitative RT-PCR was performed using primers for androgen receptor (AR), estrogen receptor beta (ERbeta), estrogen receptor alpha (ERalpha), progesterone receptor (PGR) and prostate specific antigen (PSA), with normalization to two housekeeping genes. Differences in gene expression were analyzed using the Mann-Whitney U-test. Correlation coefficients were analyzed using Spearman's test. Significant positive correlations were seen when AR and AR-dependent PSA, and ERalpha and ERalpha-dependent PGR were compared, indicating a representative population of RNA transcripts. ERbeta gene expression was significantly over-expressed in the cancer group compared with benign controls (P < 0.01). In contrast, PGR expression was significantly down-regulated in the cancer group (P < 0.05). There were no significant differences in AR, ERalpha or PSA expression between the groups. This study represents the first to show an upregulation of ERbeta gene expression in laser microdissected prostate cancer specimens. In concert with recent studies the findings suggest differential production of ERbeta splice variants, which may play important roles in the genesis of prostate cancer. (c) 2009 Wiley-Liss, Inc.

Modulation of pain by estrogens.

PubMed

Craft, Rebecca M

2007-11-01

It has become increasingly apparent that women suffer a disproportionate amount of pain during their lifetime compared to men. Over the past 15 years, a growing number of studies have suggested a variety of causes for this sex difference, from cellular to psychosocial levels of analysis. From a biological perspective, sexual differentiation of pain appears to occur similarly to sexual differentiation of other phenomena: it results in large part from organizational and activational effects of gonadal steroid hormones. The focus of this review is the activational effects of a single group of ovarian hormones, the estrogens, on pain in humans and animals. The effects of estrogens (estradiol being the most commonly examined) on experimentally induced acute pain vs. clinical pain are summarized. For clinical pain, the review is limited to a few syndromes for which there is considerable evidence for estrogenic involvement: migraine, temporomandibular disorder (TMD) and arthritis. Because estrogens can modulate the function of the nervous, immune, skeletal, and cardiovascular systems, estrogenic modulation of pain is an exceedingly complex, multi-faceted phenomenon, with estrogens producing both pro- and antinociceptive effects that depend on the extent to which each of these systems of the body is involved in a particular type of pain. Forging a more complete understanding of the myriad ways that estrogens can ameliorate vs. facilitate pain will enable us to better prevent and treat pain in both women and men.

HRT and SERMs: the good, the bad...and the lovely?

PubMed

Sandberg, Kathryn

2002-10-01

Recent studies have provided strong evidence that the biological activity of selective estrogen-receptor modulators (SERMs) depends on the conformation of the SERM-receptor complex, the estrogen-receptor-signaling mechanism, and the tissue co-regulator composition. In addition to these new observations, other studies convincingly demonstrate that estrogen has cardioprotective properties, favorably regulating genes that are crucial to vascular physiology. These novel findings could thus be key to generating SERMs that solve the risks currently associated with hormone replacement therapy. In addition, further development could result in SERMs that possess not only anti-estrogenic actions in the breast and uterus, but also estrogenic protective actions in bone and the cardiovascular system.

Estradiol Membrane-Initiated Signaling in the Brain Mediates Reproduction.

PubMed

Micevych, Paul E; Mermelstein, Paul G; Sinchak, Kevin

2017-11-01

Over the past few years our understanding of estrogen signaling in the brain has expanded rapidly. Estrogens are synthesized in the periphery and in the brain, acting on multiple receptors to regulate gene transcription, neural function, and behavior. Various estrogen-sensitive signaling pathways often operate in concert within the same cell, increasing the complexity of the system. In females, estrogen concentrations fluctuate over the estrous/menstrual cycle, dynamically modulating estrogen receptor (ER) expression, activity, and trafficking. These dynamic changes influence multiple behaviors but are particularly important for reproduction. Using the female rodent model, we review our current understanding of estradiol signaling in the regulation of sexual receptivity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Postmenopausal estrogen and progestin effects on the serum proteome

PubMed Central

2009-01-01

Background Women's Health Initiative randomized trials of postmenopausal hormone therapy reported intervention effects on several clinical outcomes, with some important differences between estrogen alone and estrogen plus progestin. The biologic mechanisms underlying these effects, and these differences, have yet to be fully elucidated. Methods Baseline serum samples were compared with samples drawn 1 year later for 50 women assigned to active hormone therapy in both the estrogen-plus-progestin and estrogen-alone randomized trials, by applying an in-depth proteomic discovery platform to serum pools from 10 women per pool. Results In total, 378 proteins were quantified in two or more of the 10 pooled serum comparisons, by using strict identification criteria. Of these, 169 (44.7%) showed evidence (nominal P < 0.05) of change in concentration between baseline and 1 year for one or both of estrogen-plus-progestin and estrogen-alone groups. Quantitative changes were highly correlated between the two hormone-therapy preparations. A total of 98 proteins had false discovery rates < 0.05 for change with estrogen plus progestin, compared with 94 for estrogen alone. Of these, 84 had false discovery rates <0.05 for both preparations. The observed changes included multiple proteins relevant to coagulation, inflammation, immune response, metabolism, cell adhesion, growth factors, and osteogenesis. Evidence of differential changes also was noted between the hormone preparations, with the strongest evidence in growth factor and inflammation pathways. Conclusions Serum proteomic analyses yielded a large number of proteins similarly affected by estrogen plus progestin and by estrogen alone and identified some proteins and pathways that appear to be differentially affected between the two hormone preparations; this may explain their distinct clinical effects. PMID:20034393

Estrogen-dependent regulation of sodium/hydrogen exchanger-3 (NHE3) expression via estrogen receptor β in proximal colon of pregnant mice.

PubMed

Choijookhuu, Narantsog; Sato, Yoko; Nishino, Tomoya; Endo, Daisuke; Hishikawa, Yoshitaka; Koji, Takehiko

2012-05-01

Although constipation is very common during pregnancy, the exact mechanism is unknown. We hypothesized that the involvement of estrogen receptor (ER) in the regulation of electrolyte transporter in the colon leads to constipation. In this study, the intestines of normal female ICR mouse and pregnant mice were examined for the expression of ERα and ERβ by immunohistochemistry and in situ hybridization. ERβ, but not ERα, was expressed in surface epithelial cells of the proximal, but not distal, colon on pregnancy days 10, 15, and 18, but not day 5, and the number of ERβ-positive cells increased significantly during pregnancy. Expression of NHE3, the gene that harbors estrogen response element, examined by immunohistochemistry and western blotting, was localized in the surface epithelial cells of the proximal colon and increased in parallel with ERβ expression. In ovariectomized mice, NHE3 expression was only marginal and was up-regulated after treatment with 17β-estradiol (E(2)), but not E(2) + ICI 182,780 (estrogen receptor antagonist). Moreover, knock-down of ERβ expression by electroporetically transfected siRNA resulted in a significant reduction of NHE3 expression. These results indicate that ERβ regulates the expression of NHE3 in the proximal colon of pregnant mice through estrogen action, suggesting the involvement of increased sodium absorption by up-regulated NHE3 in constipation during pregnancy.

Prenatal exposure of mice to diethylstilbestrol disrupts T-cell differentiation by regulating Fas/Fas ligand expression through estrogen receptor element and nuclear factor-κB motifs.

PubMed

Singh, Narendra P; Singh, Udai P; Nagarkatti, Prakash S; Nagarkatti, Mitzi

2012-11-01

Prenatal exposure to diethylstilbestrol (DES) is known to cause altered immune functions and increased susceptibility to autoimmune disease in humans. In the current study, we investigated the effect of prenatal exposure to DES on thymocyte differentiation involving apoptotic pathways. Prenatal DES exposure caused thymic atrophy, apoptosis, and up-regulation of Fas and Fas ligand (FasL) expression in thymocytes. To examine the mechanism underlying DES-mediated regulation of Fas and FasL, we performed luciferase assays using T cells transfected with luciferase reporter constructs containing full-length Fas or FasL promoters. There was significant luciferase induction in the presence of Fas or FasL promoters after DES exposure. Further analysis demonstrated the presence of several cis-regulatory motifs on both Fas and FasL promoters. When DES-induced transcription factors were analyzed, estrogen receptor element (ERE), nuclear factor κB (NF-κB), nuclear factor of activated T cells (NF-AT), and activator protein-1 motifs on the Fas promoter, as well as ERE, NF-κB, and NF-AT motifs on the FasL promoter, showed binding affinity with the transcription factors. Electrophoretic mobility-shift assays were performed to verify the binding affinity of cis-regulatory motifs of Fas or FasL promoters with transcription factors. There was shift in mobility of probes (ERE or NF-κB2) of both Fas and FasL in the presence of nuclear proteins from DES-treated cells, and the shift was specific to DES because these probes failed to shift their mobility in the presence of nuclear proteins from vehicle-treated cells. Together, the current study demonstrates that prenatal exposure to DES triggers significant alterations in apoptotic molecules expressed on thymocytes, which may affect T-cell differentiation and cause long-term effects on the immune functions.

Prenatal Exposure of Mice to Diethylstilbestrol Disrupts T-Cell Differentiation by Regulating Fas/Fas Ligand Expression through Estrogen Receptor Element and Nuclear Factor-κB Motifs

PubMed Central

Singh, Narendra P.; Singh, Udai P.; Nagarkatti, Prakash S.

2012-01-01

Prenatal exposure to diethylstilbestrol (DES) is known to cause altered immune functions and increased susceptibility to autoimmune disease in humans. In the current study, we investigated the effect of prenatal exposure to DES on thymocyte differentiation involving apoptotic pathways. Prenatal DES exposure caused thymic atrophy, apoptosis, and up-regulation of Fas and Fas ligand (FasL) expression in thymocytes. To examine the mechanism underlying DES-mediated regulation of Fas and FasL, we performed luciferase assays using T cells transfected with luciferase reporter constructs containing full-length Fas or FasL promoters. There was significant luciferase induction in the presence of Fas or FasL promoters after DES exposure. Further analysis demonstrated the presence of several cis-regulatory motifs on both Fas and FasL promoters. When DES-induced transcription factors were analyzed, estrogen receptor element (ERE), nuclear factor κB (NF-κB), nuclear factor of activated T cells (NF-AT), and activator protein-1 motifs on the Fas promoter, as well as ERE, NF-κB, and NF-AT motifs on the FasL promoter, showed binding affinity with the transcription factors. Electrophoretic mobility-shift assays were performed to verify the binding affinity of cis-regulatory motifs of Fas or FasL promoters with transcription factors. There was shift in mobility of probes (ERE or NF-κB2) of both Fas and FasL in the presence of nuclear proteins from DES-treated cells, and the shift was specific to DES because these probes failed to shift their mobility in the presence of nuclear proteins from vehicle-treated cells. Together, the current study demonstrates that prenatal exposure to DES triggers significant alterations in apoptotic molecules expressed on thymocytes, which may affect T-cell differentiation and cause long-term effects on the immune functions. PMID:22888145

17β-estradiol regulates the RNA-binding protein Nova1, which then regulates the alternative splicing of estrogen receptor β in the aging female rat brain.

PubMed

Shults, Cody L; Dingwall, Caitlin B; Kim, Chun K; Pinceti, Elena; Rao, Yathindar S; Pak, Toni R

2018-01-01

Alternative RNA splicing results in the translation of diverse protein products arising from a common nucleotide sequence. These alternative protein products are often functional and can have widely divergent actions from the canonical protein. Studies in humans and other vertebrate animals have demonstrated that alternative splicing events increase with advanced age, sometimes resulting in pathological consequences. Menopause represents a critical transition for women, where the beneficial effects of estrogens are no longer evident; therefore, factors underlying increased pathological conditions in women are confounded by the dual factors of aging and declining estrogens. Estrogen receptors (ERs) are subject to alternative splicing, the spliced variants increase following menopause, and they fail to efficiently activate estrogen-dependent signaling pathways. However, the factors that regulate the alternative splicing of ERs remain unknown. We demonstrate novel evidence supporting a potential biological feedback loop where 17β-estradiol regulates the RNA-binding protein Nova1, which, in turn, regulates the alternative splicing of ERβ. These data increase our understanding of ER alternative splicing and could have potential implications for women taking hormone replacement therapy after menopause. Copyright © 2017 Elsevier Inc. All rights reserved.

PI3K in the ventromedial hypothalamic nucleus mediates estrogenic actions on energy expenditure in female mice

USDA-ARS?s Scientific Manuscript database

Estrogens act in the ventromedial hypothalamic nucleus (VMH) to regulate body weight homeostasis. However, the molecular mechanisms underlying these estrogenic effects are unknown. We show that activation of estrogen receptor-a (ERa) stimulates neural firing of VMH neurons expressing ERa, and these ...

Osthole Stimulates Osteoblast Differentiation and Bone Formation by Activation of β-Catenin–BMP Signaling

PubMed Central

Tang, De-Zhi; Hou, Wei; Zhou, Quan; Zhang, Minjie; Holz, Jonathan; Sheu, Tzong-Jen; Li, Tian-Fang; Cheng, Shao-Dan; Shi, Qi; Harris, Stephen E; Chen, Di; Wang, Yong-Jun

2010-01-01

Osteoporosis is defined as reduced bone mineral density with a high risk of fragile fracture. Current available treatment regimens include antiresorptive drugs such as estrogen receptor analogues and bisphosphates and anabolic agents such as parathyroid hormone (PTH). However, neither option is completely satisfactory because of adverse effects. It is thus highly desirable to identify novel anabolic agents to improve future osteoporosis treatment. Osthole, a coumarin-like derivative extracted from Chinese herbs, has been shown to stimulate osteoblast proliferation and differentiation, but its effect on bone formation in vivo and underlying mechanism remain unknown. In this study, we found that local injection of Osthole significantly increased new bone formation on the surface of mouse calvaria. Ovariectomy caused evident bone loss in rats, whereas Osthole largely prevented such loss, as shown by improved bone microarchitecture, histomorphometric parameters, and biomechanical properties. In vitro studies demonstrated that Osthole activated Wnt/β-catenin signaling, increased Bmp2 expression, and stimulated osteoblast differentiation. Targeted deletion of the β-catenin and Bmp2 genes abolished the stimulatory effect of Osthole on osteoblast differentiation. Since deletion of the Bmp2 gene did not affect Osthole-induced β-catenin expression and the deletion of the β-catenin gene inhibited Osthole-regulated Bmp2 expression in osteoblasts, we propose that Osthole acts through β-catenin–BMP signaling to promote osteoblast differentiation. Our findings demonstrate that Osthole could be a potential anabolic agent to stimulate bone formation and prevent estrogen deficiency–induced bone loss. © 2010 American Society for Bone and Mineral Research. PMID:20200936

Icaritin induces MC3T3-E1 subclone14 cell differentiation through estrogen receptor-mediated ERK1/2 and p38 signaling activation.

PubMed

Wu, Zhidi; Ou, Ling; Wang, Chaopeng; Yang, Li; Wang, Panpan; Liu, Hengrui; Xiong, Yingquan; Sun, Kehuan; Zhang, Ronghua; Zhu, Xiaofeng

2017-10-01

Icaritin (ICT), a hydrolytic product of icariin from the genus Epimedium, has many indicated pharmacological and biological activities. Several studies have shown that ICT has potential osteoprotective effects, including stimulation of osteoblast differentiation and inhibition of osteoclast differentiation. However, the molecular mechanism for this anabolic action of ICT remains largely unknown. Here, we found that ICT could enhance MC3T3-E1 subclone 14 preosteoblastic cell differentiation associated with increased mRNA levels and protein expression of the differentiation markers alkaline phosphatase (ALP), type 1 collagen (COL1), osteocalcin (OC), osteoponin (OPN) and runt-related transcription factor 2 (RUNX2), and improved mineralization, confirmed by bone nodule formation and collagen synthesis. To characterize the underlying mechanisms, we examined the effect of ICT on estrogen receptor (ER) and mitogen-activated protein kinase (MAPK) signaling. ICT treatment induced p38 kinase and extracellular signal-regulated kinase 1/2 (ERK1/2) activation, but it demonstrated at the same time point no effect on activation of c-Jun N-terminal kinase (JNK). ER antagonist ICI182780, p38 antagonist SB203580 and ERK1/2 antagonist PD98059 markedly inhibited the ICT-induced the mRNA expression of ALP, COL1, OC and OPN. ICI182780 attenuated the ICT-induced phosphorylation of p38 and ERK1/2. These observations indicate a potential mechanism of osteogenic effects of ICT involving the ERK1/2 and p38 pathway activation through the ER. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Metabolic Impact Of Sex Hormones On Obesity

PubMed Central

Brown, Lynda M.; Gent, Lana; Davis, Kathryn; Clegg, Deborah J.

2010-01-01

Obesity and its associated health disorders and costs are increasing. Men and postmenopausal women have greater risk of developing complications of obesity than younger women. Within the brain, the hypothalamus is an important regulator of energy homeostasis. Two of its sub-areas, the ventrolateral portion of the ventral medial nucleus (VL VMN) and the arcuate (ARC) respond to hormones and other signals to control energy intake and expenditure. When large lesions are made in the hypothalamus which includes both the VL VMN and the ARC, animals eat more, have reduced energy expenditure, and become obese. The ARC and the VL VMN, in addition to other regions in the hypothalamus, have been demonstrated to contain estrogen receptors. There are two estrogen receptors, estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). We and others have previously demonstrated that activation of ERα by estrogens reduces food intake and increases body weight. This review focuses on the relative contribution of activation of ERα by estrogens in the ARC and the VL VMN in the regulation of food intake and body weight. Additionally, estrogen receptors have been found in many peripheral tissues including adipose tissue. Estrogens are thought to have direct effects on adipose tissue and estrogens may provide anti-inflammatory properties both in the periphery and the in the central nervous system (CNS) which may protect women from diseases associated with inflammation. Understanding the mechanisms by which estrogens regulate body weight and inflammation will assist in determining potential therapeutic agents for menopausal women to decrease the propensity of diseases associated with obesity. PMID:20441773

Baicalin, a Flavone, Induces the Differentiation of Cultured Osteoblasts

PubMed Central

Guo, Ava J. Y.; Choi, Roy C. Y.; Cheung, Anna W. H.; Chen, Vicky P.; Xu, Sherry L.; Dong, Tina T. X.; Chen, Ji J.; Tsim, Karl W. K.

2011-01-01

Flavonoids, a group of natural compounds found in a variety of vegetables and herbal medicines, have been intensively reported on regarding their estrogen-like activities and particularly their ability to affect bone metabolism. Here, different subclasses of flavonoids were screened for their osteogenic properties by measuring alkaline phosphatase activity in cultured rat osteoblasts. The flavone baicalin derived mainly from the roots of Scutellaria baicalensis showed the strongest induction of alkaline phosphatase activity. In cultured osteoblasts, application of baicalin increased significantly the osteoblastic mineralization and the levels of mRNAs encoding the bone differentiation markers, including osteonectin, osteocalcin, and collagen type 1α1. Interestingly, the osteogenic effect of baicalin was not mediated by its estrogenic activity. In contrast, baicalin promoted osteoblastic differentiation via the activation of the Wnt/β-catenin signaling pathway; the activation resulted in the phosphorylation of glycogen synthase kinase 3β and, subsequently, induced the nuclear accumulation of the β-catenin, leading to the transcription activation of Wnt-targeted genes for osteogenesis. The baicalin-induced osteogenic effects were fully abolished by DKK-1, a blocker of Wnt/β-catenin receptor. Moreover, baicalin also enhanced the mRNA expression of osteoprotegerin, which could regulate indirectly the activation of osteoclasts. Taken together, our results suggested that baicalin could act via Wnt/β-catenin signaling to promote osteoblastic differentiation. The osteogenic flavonoids could be very useful in finding potential drugs, or food supplements, for treating post-menopausal osteoporosis. PMID:21652696

miRNA as a New Regulatory Mechanism of Estrogen Vascular Action.

PubMed

Pérez-Cremades, Daniel; Mompeón, Ana; Vidal-Gómez, Xavier; Hermenegildo, Carlos; Novella, Susana

2018-02-06

The beneficial effects of estrogen on the cardiovascular system have been reported extensively. In fact, the incidence of cardiovascular diseases in women is lower than in age-matched men during their fertile stage of life, a benefit that disappears after menopause. These sex-related differences point to sexual hormones, mainly estrogen, as possible cardiovascular protective factors. The regulation of vascular function by estrogen is mainly related to the maintenance of normal endothelial function and is mediated by both direct and indirect gene transcription through the activity of specific estrogen receptors. Some of these mechanisms are known, but many remain to be elucidated. In recent years, microRNAs have been established as non-coding RNAs that regulate the expression of a high percentage of protein-coding genes in mammals and are related to the correct function of human physiology. Moreover, within the cardiovascular system, miRNAs have been related to physiological and pathological conditions. In this review, we address what is known about the role of estrogen-regulated miRNAs and their emerging involvement in vascular biology.

The antiestrogen ICI 182,780 decreases the expression of estrogen receptor-alpha but has no effect on estrogen receptor-beta and androgen receptor in rat efferent ductules

PubMed Central

Oliveira, Cleida A; Nie, Rong; Carnes, Kay; Franca, Luiz R; Prins, Gail S; Saunders, Philippa TK; Hess, Rex A

2003-01-01

Background The antiestrogen ICI 182,780 has been used successfully as an alternative experimental model for the study of estrogen action in the rodent adult male reproductive tract. Although ICI 182,780 causes severe alterations in testicular and efferent ductule morphology and function, the effects on the expression of estrogen and androgen receptors in the male have not been shown. Methods In the present study, adult male rats were treated with ICI 182,780 for 7 to 150 days, to evaluate the time-response effects of the treatment on the pattern of ERα, ERβ and AR protein expression in the efferent ductules. The receptors were localized using immunohistochemistry. Results ERα, ERβ and AR have distinct cellular distribution in the testis and efferent ductules. Staining for ERα is nearly opposite of that for ERβ, as ERα shows an increase in staining intensity from proximal to distal efferent ductules, whereas ERβ shows the reverse. Androgen receptor follows that of ERα. ICI 182,780 caused a gradual but dramatic decrease in ERα expression in the testis and efferent ductules, but no change in ERβ and AR expression. Conclusions The differential response of ERα and ERβ proteins to ICI 182,780 indicates that these receptors are regulated by different mechanisms in the male reproductive tract. PMID:14613549

The ERa-PI3K cascade in proopiomelanocortin progenitor neurons regulates feeding and glucose balance in female mice

USDA-ARS?s Scientific Manuscript database

Estrogens act upon estrogen receptor (ER)a to inhibit feeding and improve glucose homeostasis in female animals. However, the intracellular signals that mediate these estrogenic actions remain unknown. Here, we report that anorexigenic effects of estrogens are blunted in female mice that lack ERa sp...

MEASUREMENT OF ESTROGEN-INDUCED VITELLOGENIN AND VITELLINE ENVELOPE PROTEIN MRNA IN SHEEPSHEAD MINNOW (CYPRINODON VARIEGATUS) USING QUANTITATIVE REAL-TIME PCR TECHNOLOGY

EPA Science Inventory

Many environmentally persistent chemicals found in both European and U.S. waterways can act as estrogens by binding to estrogen receptors and modifying the expression of genes regulated by endogenous estrogens. Synthesis of female-specific proteins (Vitellogenin [VTG], vitelline ...

The role of estrogens for male bone health.

PubMed

Ohlsson, Claes; Vandenput, Liesbeth

2009-06-01

Sex steroids are important for the growth and maintenance of both the female and the male skeleton. However, the relative contribution of androgens versus estrogens in the regulation of the male skeleton is unclear. Experiments using mice with inactivated sex steroid receptors demonstrated that both activation of the estrogen receptor (ER)alpha and activation of the androgen receptor result in a stimulatory effect on both the cortical and trabecular bone mass in males. ERbeta is of no importance for the skeleton in male mice while it modulates the ERalpha-action on bone in female mice. Previous in vitro studies suggest that the membrane G protein-coupled receptor GPR30 also might be a functional ER. Our in vivo analyses of GPR30-inactivated mice revealed no function of GPR30 for estrogen-mediated effects on bone mass but it is required for normal regulation of the growth plate and estrogen-mediated insulin-secretion. Recent clinical evidence suggests that a threshold exists for estrogen effects on bone in men: rates of bone loss and fracture risk seem to be the highest in men with estradiol levels below this threshold. Taken together, even though these findings do not exclude an important role for testosterone in male skeletal homeostasis, it is now well-established that estrogens are important regulators of bone health in men.

“Rapid Estrogen Signaling in the Brain: Implications for the Fine-Tuning of Neuronal Circuitry”

PubMed Central

Srivastava, Deepak P.; Waters, Elizabeth M.; Mermelstein, Paul G.; Kramár, Enikö A.; Shors, Tracey J.; Liu, Feng

2011-01-01

Rapid actions of estrogens were first described over 40 years ago. However, the importance of rapid estrogen-mediated actions in the central nervous system (CNS) has only now becoming apparent. Several lines of evidence demonstrate that rapid estrogen-mediated signaling elicits potent effects on molecular and cellular events, resulting in the fine-tuning of neuronal circuitry. At an ultrastructural level, the details of estrogen receptor localization and how these are regulated by the circulating hormone and age, are now becoming evident. Furthermore, the mechanisms that allow membrane-associated estrogen receptors to couple with intracellular signaling pathways are also now being revealed. Elucidation of complex actions of rapid estrogen-mediated signaling on synaptic proteins, connectivity and synaptic function in pyramidal neurons has demonstrated that this neurosteroid engage specific mechanisms in different areas of the brain. The regulation of synaptic properties most likely underlies the ‘fine-tuning’ of neuronal circuitry. This in turn may influence how learned behaviors are encoded by different circuitry in male and female subjects. Importantly, as estrogens have been suggested as potential treatments of a number of disorders of the CNS, advancements in our understanding of rapid estrogen signaling in the brain will serve to aid in the development of potential novel estrogen-based treatments. PMID:22072656

Estrogen Regulates Bone Turnover by Targeting RANKL Expression in Bone Lining Cells.

PubMed

Streicher, Carmen; Heyny, Alexandra; Andrukhova, Olena; Haigl, Barbara; Slavic, Svetlana; Schüler, Christiane; Kollmann, Karoline; Kantner, Ingrid; Sexl, Veronika; Kleiter, Miriam; Hofbauer, Lorenz C; Kostenuik, Paul J; Erben, Reinhold G

2017-07-25

Estrogen is critical for skeletal homeostasis and regulates bone remodeling, in part, by modulating the expression of receptor activator of NF-κB ligand (RANKL), an essential cytokine for bone resorption by osteoclasts. RANKL can be produced by a variety of hematopoietic (e.g. T and B-cell) and mesenchymal (osteoblast lineage, chondrocyte) cell types. The cellular mechanisms by which estrogen acts on bone are still a matter of controversy. By using murine reconstitution models that allow for selective deletion of estrogen receptor-alpha (ERα) or selective inhibition of RANKL in hematopoietic vs. mesenchymal cells, in conjunction with in situ expression profiling in bone cells, we identified bone lining cells as important gatekeepers of estrogen-controlled bone resorption. Our data indicate that the increase in bone resorption observed in states of estrogen deficiency in mice is mainly caused by lack of ERα-mediated suppression of RANKL expression in bone lining cells.

A calixpyrrole derivative acts as an antagonist to GPER, a G-protein coupled receptor: mechanisms and models

PubMed Central

Lappano, Rosamaria; Rosano, Camillo; Pisano, Assunta; Santolla, Maria Francesca; De Francesco, Ernestina Marianna; De Marco, Paola; Dolce, Vincenza; Ponassi, Marco; Felli, Lamberto; Cafeo, Grazia; Kohnke, Franz Heinrich; Abonante, Sergio; Maggiolini, Marcello

2015-01-01

ABSTRACT Estrogens regulate numerous pathophysiological processes, mainly by binding to and activating estrogen receptor (ER)α and ERβ. Increasing amounts of evidence have recently demonstrated that G-protein coupled receptor 30 (GPR30; also known as GPER) is also involved in diverse biological responses to estrogens both in normal and cancer cells. The classical ER and GPER share several features, including the ability to bind to identical compounds; nevertheless, some ligands exhibit opposed activity through these receptors. It is worth noting that, owing to the availability of selective agonists and antagonists of GPER for research, certain differential roles elicited by GPER compared with ER have been identified. Here, we provide evidence on the molecular mechanisms through which a calixpyrrole derivative acts as a GPER antagonist in different model systems, such as breast tumor cells and cancer-associated fibroblasts (CAFs) obtained from breast cancer patients. Our data might open new perspectives toward the development of a further class of selective GPER ligands in order to better dissect the role exerted by this receptor in different pathophysiological conditions. Moreover, calixpyrrole derivatives could be considered in future anticancer strategies targeting GPER in cancer cells. PMID:26183213

Distinct Hypothalamic Neurons Mediate Estrogenic Effects on Energy Homeostasis and Reproduction

PubMed Central

Xu, Yong; Nedungadi, Thekkethil P.; Zhu, Liangru; Sobhani, Nasim; Irani, Boman G.; Davis, Kathryn E.; Zhang, Xiaorui; Zou, Fang; Gent, Lana M.; Hahner, Lisa D.; Khan, Sohaib A.; Elias, Carol F.; Elmquist, Joel K.; Clegg, Deborah J.

2011-01-01

Summary Estrogens regulate body weight and reproduction primarily through actions on estrogen receptor-α (ERα). However, ERα-expressing cells mediating these effects are not identified. We demonstrate that brain-specific deletion of ERα in female mice causes abdominal obesity stemming from both hyperphagia and hypometabolism. Hypometabolism and abdominal obesity, but not hyperphagia, are recapitulated in female mice lacking ERα in hypothalamic steroidogenic factor-1 (SF1) neurons. In contrast, deletion of ERα in hypothalamic pro-opiomelanocortin (POMC) neurons leads to hyperphagia, without directly influencing energy expenditure or fat distribution. Further, simultaneous deletion of ERα from both SF1 and POMC neurons causes hypometabolism, hyperphagia and increased visceral adiposity. Additionally, female mice lacking ERα in SF1 neurons develop anovulation and infertility, while POMC-specific deletion of ERα inhibits negative feedback regulation of estrogens and impairs fertility in females. These results indicate that estrogens act on distinct hypothalamic ERα neurons to regulate different aspects of energy homeostasis and reproduction. PMID:21982706

MiR-133 is Involved in Estrogen Deficiency-Induced Osteoporosis through Modulating Osteogenic Differentiation of Mesenchymal Stem Cells.

PubMed

Lv, Hao; Sun, Yujie; Zhang, Yuchen

2015-05-27

MiR-133 expression is dysregulated in postmenopausal osteoporosis. However, its role in postmenopausal osteoporosis is still not well understood. In the current study, we explore how estrogen deficiency affects miR-133 expression and how miR-133 is involved in osteogenic differentiation of mesenchymal stem cells (MSCs). qRT-PCR analysis was performed to assess miR-133 expression in MSCs isolated from bone marrow of an ovariectomized (OVX) animal model and postmenopausal osteoporosis patients (PMOP) and their corresponding controls. The binding between miR-133 and predicted target SLC39A1 was verified using dual luciferase assay and Western blot analysis. The effect of miR-133 and SLC39A1 on osteogenic differentiation of MSCs was assessed through measuring alkaline phosphatase (ALP), mineralization nodules, and osteoblast-specific genes Runx2 and Osterix expression. miR-133 expression is significantly enhanced as a result of estrogen deficiency. Its overexpression is negatively correlated to osteogenic differentiation of hMSCs. SLC39A1 showed an inverse expression trend to miR-133 during the differentiation. miR-133 can directly target 3'UTR of SLC39A1 and thereby modulate its expression in hMSCs. The miR-133-SLC39A1 axis might play an important role in osteogenic differentiation of hMSCs. SLC39A1 can promote ALP activity and formation of mineralization nodules. In addition, SLC39A1 expression level is also positively correlated with RUNX2 and Osterix. Estrogen deficiency is associated with miR-133 overexpression. MiR-133 can induce postmenopausal osteoporosis by weakening osteogenic differentiation of hMSCs, at least partly through repressing SLC39A1 expression.

MiR-133 is Involved in Estrogen Deficiency-Induced Osteoporosis through Modulating Osteogenic Differentiation of Mesenchymal Stem Cells

PubMed Central

Lv, Hao; Sun, Yujie; Zhang, Yuchen

2015-01-01

Background MiR-133 expression is dysregulated in postmenopausal osteoporosis. However, its role in postmenopausal osteoporosis is still not well understood. In the current study, we explore how estrogen deficiency affects miR-133 expression and how miR-133 is involved in osteogenic differentiation of mesenchymal stem cells (MSCs). Material/Methods qRT-PCR analysis was performed to assess miR-133 expression in MSCs isolated from bone marrow of an ovariectomized (OVX) animal model and postmenopausal osteoporosis patients (PMOP) and their corresponding controls. The binding between miR-133 and predicted target SLC39A1 was verified using dual luciferase assay and Western blot analysis. The effect of miR-133 and SLC39A1 on osteogenic differentiation of MSCs was assessed through measuring alkaline phosphatase (ALP), mineralization nodules, and osteoblast-specific genes Runx2 and Osterix expression. Results miR-133 expression is significantly enhanced as a result of estrogen deficiency. Its overexpression is negatively correlated to osteogenic differentiation of hMSCs. SLC39A1 showed an inverse expression trend to miR-133 during the differentiation. miR-133 can directly target 3′UTR of SLC39A1 and thereby modulate its expression in hMSCs. The miR-133-SLC39A1 axis might play an important role in osteogenic differentiation of hMSCs. SLC39A1 can promote ALP activity and formation of mineralization nodules. In addition, SLC39A1 expression level is also positively correlated with RUNX2 and Osterix. Conclusions Estrogen deficiency is associated with miR-133 overexpression. MiR-133 can induce postmenopausal osteoporosis by weakening osteogenic differentiation of hMSCs, at least partly through repressing SLC39A1 expression. PMID:26013661

Estrogenic Activity of Hyperforin in MCF-7 Human Breast Cancer Cells Transfected with Estrogen Receptor.

PubMed

Kwon, Joseph; Oh, Kyung Seo; Cho, Se-Young; Bang, Mi Ae; Kim, Hwan Seon; Vaidya, Bipin; Kim, Duwoon

2016-11-01

Hyperforin, a major active compound of St. John's wort extract, affects estrogenic activity. In this study, the compound evoked estrogen response element-dependent luciferase activity and cell proliferation in MCF-7 cells. Hyperforin-induced cell proliferation was significantly inhibited by the estrogen receptor antagonist ICI 182,780. These results suggested that hyperforin had estrogenic and cell proliferation activities, which were stimulated via the estrogen receptor. Compared to 17 β -estradiol, hyperforin showed significantly lower estrogenic activity and cell proliferation. The mechanism underlying the estrogenic activity of hyperforin was unknown, therefore, in this study, for the first time, the expression and post-translational modification of proteins were determined and compared among control, 17 β -estradiol-treated, and hyperforin-treated cells using proteomic techniques. A total of 453 proteins were identified, of which 282 proteins were significantly modulated in hyperforin-treated cells compared to 17 β -estradiol-treated cells. Ingenuity pathway analysis also demonstrated that hyperforin treatment induced less cell proliferation than 17 β -estradiol by downregulating estrogen receptor 1. Protein network analysis showed that cell proliferation was regulated mainly by cyclin D1 and extracellular signal-regulated kinases. In conclusion, although, hyperforin exhibited lower estrogenic activity than 17 β -estradiol, the compound induced lower levels of cancer cell proliferation in vitro . Georg Thieme Verlag KG Stuttgart · New York.

Presence of estrogen receptors in human myeloid monocytic cells (THP-1 cell line).

PubMed

Cutolo, M; Villaggio, B; Bisso, A; Sulli, A; Coviello, D; Dayer, J M

2001-01-01

To test THP-1 cells for the presence of estrogen receptors (ER) since studies have demonstrated in vivo and in vitro, the influence of estrogens on cells involved in immune response (i.e. macrophages), and since it has been demonstrated that human myeloid monocytic THP-1 cells acquire phenotypic and functional macrophage-like features after incubation with several cytokines or pharmacological agents. Stimulation of THP-1 cells with phorbol myristate acetate (PMA) to prompt their differentiation into macrophage-like cells and evaluation of the possible induction of ER. The expression of ER was analyzed by immunocytochemical assay, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot analysis. After stimulation by PMA, the human myeloid monocytic THP-1 cells showed the presence of ER, together with markers of monocytic cell differentiation such as CD68, CD54 and HLA-DR. Estrogen effects may be exerted directly through ER on monocytes/macrophages. PMA-treated THP-1 cells may constitute a useful in vitro model to determine the effects of estrogens on macrophage-like cells and their implications in the inflammatory and immune processes.

Sex hormone-binding globulin b expression in the rainbow trout ovary prior to sex differentiation.

PubMed

Pérez, Claudio; Araneda, Cristian; Estay, Francisco; Díaz, Nelson F; Vizziano-Cantonnet, Denise

2018-04-01

Salmonids have two sex hormone-binding globulin (Shbg) paralogs. Shbga is mainly expressed in the liver, while Shbgb is secreted by the granulosa cells of the rainbow trout ovary. Coexpression of shbgb and the gonadal aromatase cyp19a1a mRNAs been observed in granulosa cells, suggesting a physiological coordination between Shbgb expression and estrogen synthesis. As estrogens are essential for female sex determination in the fish ovary, we propose that Shbgb participates in early ovarian differentiation, either by binding with estrogen or through another mechanism that remains to be discovered. To elucidate this potential role, monosex populations of female trout were studied during the molecular ovarian differentiation period (28-56 dpf). shbgb mRNA expression was measured using qPCR and compared with expression of genes for other ovarian markers (cyp19a1a, foxl2, follistatin, and estrogen receptors). shbgb transcript expression was detected during the final stages of embryonic development (21-26 dpf) and during molecular ovarian differentiation (32-52 dpf) after hatching (which occurred at 31 dpf). In situ hybridization localized shbgb transcription to the undifferentiated ovary at 42 dpf, and shbgb and cyp19a1a mRNA showed similar expression patterns. These results suggest that Shbgb is involved in early ovarian differentiation, supporting an important role for the salmonid shbgb gene in sex determination. Copyright © 2017 Elsevier Inc. All rights reserved.

Unique roles of estrogen-dependent Pten control in epithelial cell homeostasis of mouse vagina.

PubMed

Miyagawa, S; Sato, M; Sudo, T; Yamada, G; Iguchi, T

2015-02-19

Numerous studies support a role of phosphatase and tensin homolog deleted from chromosome 10 (Pten) as a tumor suppressor gene that controls epithelial cell homeostasis to prevent tumor formation. Mouse vaginal epithelium cyclically exhibits cell proliferation and differentiation in response to estrogen and provides a unique model for analyzing homeostasis of stratified squamous epithelia. We analyzed vaginal epithelium-specific Pten conditional knockout (CKO) mice to provide new insights into Pten/phosphoinositide-3-kinase (PI3K)/Akt function. The vaginal epithelium of ovariectomized (OVX) mice (control) was composed of 1-2 layers of cuboidal cells, whereas OVX CKO mice exhibited epithelial hyperplasia in the suprabasal cells with increased cell mass and mucin production. This is possibly due to misactivation of mammalian target of rapamycin and mitogen-activated protein kinase. Intriguingly, estrogen administration to OVX Pten CKO mice induced stratification and keratinized differentiation in the vaginal epithelium, as in estrogen-treated controls. We found that Pten is exclusively expressed in the suprabasal cells in the absence of estrogens, whereas estrogen administration induced Pten expression in the basal cells. This suggests that Pten acts to prevent excessive cell proliferation as in the case of other squamous tissues. Thus, Pten exhibits a dual role on the control of vaginal homeostasis, depending on whether estrogens are present or absent. Our results provide new insights into how Pten functions in tissue homeostasis.

Dissolved organic matter and estrogen interactions regulate estrogen removal in the aqueous environment: A review.

PubMed

Ma, Li; Yates, Scott R

2018-06-03

This review summarizes the characterization and quantification of interactions between dissolved organic matter (DOM) and estrogens as well as the effects of DOM on aquatic estrogen removal. DOM interacts with estrogens via binding or sorption mechanisms like π-π interaction and hydrogen bonding. The binding affinity is evaluated in terms of organic-carbon-normalized sorption coefficient (Log K OC ) which varies with types and composition of DOM. DOM has been suggested to be a more efficient sorbent compared with other matrices, such as suspended particulate matter, sediment and soil; likely associated with its large surface area and concentrated carbon content. As a photosensitizer, DOM enhanced estrogen photodegradation when the concentration of DOM was below a threshold value, and when above, the acceleration effect was not observed. DOM played a dual role in affecting biodegradation of estrogens depending on the recalcitrance of the DOM and the nutrition status of the degraders. DOM also acted as an electron shuttle (redox mediator) mediating the degradation of estrogens. DOM hindered enzyme-catalyzed removal of estrogens while enhanced their transformation during the simultaneous photo-enzymatic process. Membrane rejection of estrogens was pronounced for hydrophobic DOM with high aromaticity and phenolic moiety content. Elimination of estrogens via photolysis, biodegradation, enzymolysis and membrane rejection in the presence of DOM is initiated by sorption, accentuating the role of DOM as a mediator in regulating aquatic estrogen removal. Published by Elsevier B.V.

Progesterone Action in Endometrial Cancer, Endometriosis, Uterine Fibroids, and Breast Cancer

PubMed Central

Kim, J. Julie; Kurita, Takeshi

2013-01-01

Progesterone receptor (PR) mediates the actions of the ovarian steroid progesterone, which together with estradiol regulates gonadotropin secretion, prepares the endometrium for implantation, maintains pregnancy, and differentiates breast tissue. Separation of estrogen and progesterone actions in hormone-responsive tissues remains a challenge. Pathologies of the uterus and breast, including endometrial cancer, endometriosis, uterine fibroids, and breast cancer, are highly associated with estrogen, considered to be the mitogenic factor. Emerging evidence supports distinct roles of progesterone and its influence on the pathogenesis of these diseases. Progesterone antagonizes estrogen-driven growth in the endometrium, and insufficient progesterone action strikingly increases the risk of endometrial cancer. In endometriosis, eutopic and ectopic tissues do not respond sufficiently to progesterone and are considered to be progesterone-resistant, which contributes to proliferation and survival. In uterine fibroids, progesterone promotes growth by increasing proliferation, cellular hypertrophy, and deposition of extracellular matrix. In normal mammary tissue and breast cancer, progesterone is pro-proliferative and carcinogenic. A key difference between these tissues that could explain the diverse effects of progesterone is the paracrine interactions of PR-expressing stroma and epithelium. Normal endometrium is a mucosa containing large quantities of distinct stromal cells with abundant PR, which influences epithelial cell proliferation and differentiation and protects against carcinogenic transformation. In contrast, the primary target cells of progesterone in the breast and fibroids are the mammary epithelial cells and the leiomyoma cells, which lack specifically organized stromal components with significant PR expression. This review provides a unifying perspective for the diverse effects of progesterone across human tissues and diseases. PMID:23303565

G protein-coupled receptor 30 regulates trophoblast invasion and its deficiency is associated with preeclampsia.

PubMed

Tong, Chao; Feng, Xiang; Chen, Jun; Qi, Xingchen; Zhou, Liyuan; Shi, Shuming; Kc, Kamana; Stanley, Joanna L; Baker, Philip N; Zhang, Hua

2016-04-01

Preeclampsia is known to be associated with reduced circulating levels of estrogen. The effects of estrogen in preeclampsia are normally mediated by the classical estrogen receptors. Intriguingly, a novel estrogen receptor, G protein-coupled receptor 30 (GPR30), has been recently found to play an important role in several estrogenic effects. However, the mechanisms by which GPR30 may mediate the development of preeclampsia remain unknown. We observed that the expression of GPR30 in placental trophoblast cells is lower in preeclamptic placentas compared with normotensive controls. We then investigated the role of GPR30 in trophoblast cell invasion by utilizing placental explants and the immortalized human trophoblast cell line (HTR8/SVneo). The selective GPR30 agonist G1 and a general estrogen receptors agonist 17-β-estradiol (E2) both improved trophoblast cells invasion by upregulating MMP9 expression and the PI3K-Akt signaling pathway. This effect was abolished by a selective GPR30 inhibitor G15, implying that GPR30 may be involved in regulating trophoblast invasion, and that down-regulation of this receptor may result in the development of preeclampsia. The present study suggests that GPR30 is a critical regulator of trophoblast cell invasion, and as such may be a potential therapeutic interventional target for preeclampsia and other pregnancy complications resulting from impaired trophoblast invasion.

Modulated Expression of Genes Encoding Estrogen Metabolizing Enzymes by G1-Phase Cyclin-Dependent Kinases 6 and 4 in Human Breast Cancer Cells

PubMed Central

Jia, Yi; Domenico, Joanne; Swasey, Christina; Wang, Meiqin; Gelfand, Erwin W.; Lucas, Joseph J.

2014-01-01

G1-phase cell cycle defects, such as alterations in cyclin D1 or cyclin-dependent kinase (cdk) levels, are seen in most tumors. For example, increased cyclin D1 and decreased cdk6 levels are seen in many human breast tumors. Overexpression of cdk6 in breast tumor cells in culture has been shown to suppress proliferation, unlike the growth stimulating effects of its close homolog, cdk4. In addition to directly affecting proliferation, alterations in cdk6 or cdk4 levels in breast tumor cells also differentially influence levels of numerous steroid metabolic enzymes (SMEs), including those involved in estrogen metabolism. Overexpression of cdk6 in tumor cell lines having low cdk6 resulted in decreased levels of mRNAs encoding aldo-keto reductase (AKR)1C1, AKR1C2 and AKR1C3, which are hydroxysteroid dehydrogenases (HSDs) involved in steroid hormone metabolism. In contrast, increasing cdk4 dramatically increased these transcript levels, especially those encoding AKR1C3, an enzyme that converts estrone to 17β-estradiol, a change that could result in a pro-estrogenic state favoring tumor growth. Effects on other estrogen metabolizing enzymes, including cytochrome P450 (CYP) 19 aromatase, 17β-HSD2, and CYP1B1 transcripts, were also observed. Interactions of cdk6 and cdk4, but not cyclin D1, with the promoter region of a cdk-regulated gene, 17β-HSD2, were detected. The results uncover a previously unsuspected link between the cell cycle and hormone metabolism and differential roles for cdk6 and cdk4 in a novel mechanism for pre-receptor control of steroid hormone action, with important implications for the origin and treatment of steroid hormone-dependent cancers. PMID:24848372

4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol}, 1 a novel resveratrol analog, differentially regulates estrogen receptors α and β in breast cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronghe, Amruta; Chatterjee, Anwesha

Breast cancer is a public health concern worldwide. Prolonged exposure to estrogens has been implicated in the development of breast neoplasms. Epidemiologic and experimental evidence suggest a chemopreventive role of phytoestrogens in breast cancers. Resveratrol, a naturally occurring phytoestrogen, has been shown to have potent anti-cancer properties. However, poor efficacy and bioavailability have prevented the use of resveratrol in clinics. In order to address these problems, we have synthesized a combinatorial library of azaresveratrol analogs and tested them for their ability to inhibit the proliferation of breast cancer cells. We have recently shown that 4-(E)-{(p-tolylimino)-methylbenzene-1,2-diol} (TIMBD), has better anti-cancer propertiesmore » than resveratrol and any other resveratrol analog we have synthesized so far. The objective of this study was to investigate the regulation of estrogen receptors (ERs) α and β by TIMBD in breast cancer cell lines. We demonstrate that TIMBD significantly induces the mRNA and protein expression levels of ERβ and inhibits that of ERα. TIMBD inhibits mRNA and protein expression levels of oncogene c-Myc, and cell cycle protein cyclin D1, which are important regulators of cellular proliferation. TIMBD significantly induces protein expression levels of tumor suppressor genes p53 and p21 in MCF-7 cells. TIMBD inhibits c-Myc in an ERβ-dependent fashion in MCF-10 A and ERβ1-transfected MDA-MB-231 cells, suggesting regulation of ERs as an important upstream mechanism of this analog. ERβ plays a partial role in inhibition of proliferation by TIMBD while ERα overexpression does not significantly affect TIMBD's inhibition. - Highlights: • Resveratrol analog TIMBD inhibits growth of breast cancer cells. • TIMBD induces protein expression levels of ERβ and inhibits that of ERα. • TIMBD inhibits c-Myc and cyclin D1, and induces p53 and p21. • TIMBD suppresses c-Myc in an ER-dependent fashion.« less

The human oxytocin gene promoter is regulated by estrogens.

PubMed

Richard, S; Zingg, H H

1990-04-15

Gonadal steroids affect brain function primarily by altering the expression of specific genes, yet the specific mechanisms by which neuronal target genes undergo such regulation are unknown. Recent evidence suggests that the expression of the neuropeptide gene for oxytocin (OT) is modulated by estrogens. We therefore examined the possibility that this regulation occurred via a direct interaction of the estrogen-receptor complex with cis-acting elements flanking the OT gene. DNA-mediated gene transfer experiments were performed using Neuro-2a neuroblastoma cells and chimeric plasmids containing portions of the human OT gene 5'-glanking region linked to the chloramphenicol acetyltransferase gene. We identified a 19-base pair region located at -164 to -146 upstream of the transcription start site which is capable of conferring estrogen responsiveness to the homologous as well as to a heterologous promoter. The hormonal response is strictly dependent on the presence of intracellular estrogen receptors, since estrogen induced stimulation occurred only in Neuro-2a cells co-transfected with an expression vector for the human estrogen receptor. The identified region contains a novel imperfect palindrome (GGTGACCTTGACC) with sequence similarity to other estrogen response elements (EREs). To define cis-acting elements that function in synergism with the ERE, sequences 3' to the ERE were deleted, including the CCAAT box, two additional motifs corresponding to the right half of the ERE palindrome (TGACC), as well as a CTGCTAA heptamer similar to the "elegans box" found in Caenorhabditis elegans. Interestingly, optimal function of the identified ERE was fully independent of these elements and only required a short promoter region (-49 to +36). Our studies define a molecular mechanism by which estrogens can directly modulate OT gene expression. However, only a subset of OT neurons are capable of binding estrogens, therefore, direct action of estrogens on the OT gene may be restricted to a subpopulation of OT neurons.

Defective bone formation and anabolic response to exogenous estrogen in mice with targeted disruption of endothelial nitric oxide synthase.

PubMed

Armour, K E; Armour, K J; Gallagher, M E; Gödecke, A; Helfrich, M H; Reid, D M; Ralston, S H

2001-02-01

Nitric oxide (NO) is a pleiotropic signaling molecule that is produced by bone cells constitutively and in response to diverse stimuli such as proinflammatory cytokines, mechanical strain, and sex hormones. Endothelial nitric oxide synthase (eNOS) is the predominant NOS isoform expressed in bone, but its physiological role in regulating bone metabolism remains unclear. Here we studied various aspects of bone metabolism in female mice with targeted disruption of the eNOS gene. Mice with eNOS deficiency (eNOS KO) had reduced bone mineral density, and cortical thinning when compared with WT controls and histomorphometric analysis of bone revealed profound abnormalities of bone formation, with reduced osteoblast numbers, surfaces and mineral apposition rate. Studies in vitro showed that osteoblasts derived from eNOS KO mice had reduced rates of growth when compared with WT and were less well differentiated as reflected by lower levels of alkaline phosphatase activity. Mice with eNOS deficiency lost bone normally following ovariectomy but exhibited a significantly blunted anabolic response to high dose exogenous estrogen. We conclude that the eNOS pathway plays an essential role in regulating bone mass and bone turnover by modulating osteoblast function.

Developmental Exposure to Estrogen Alters Differentiation and Epigenetic Programming in a Human Fetal Prostate Xenograft Model

PubMed Central

Saffarini, Camelia M.; McDonnell-Clark, Elizabeth V.; Amin, Ali; Huse, Susan M.; Boekelheide, Kim

2015-01-01

Prostate cancer is the most frequent non-cutaneous malignancy in men. There is strong evidence in rodents that neonatal estrogen exposure plays a role in the development of this disease. However, there is little information regarding the effects of estrogen in human fetal prostate tissue. This study explored early life estrogen exposure, with and without a secondary estrogen and testosterone treatment in a human fetal prostate xenograft model. Histopathological lesions, proliferation, and serum hormone levels were evaluated at 7, 30, 90, and 200-day time-points after xenografting. The expression of 40 key genes involved in prostatic glandular and stromal growth, cell-cycle progression, apoptosis, hormone receptors and tumor suppressors was evaluated using a custom PCR array. Epigenome-wide analysis of DNA methylation was performed on whole tissue, and laser capture-microdissection (LCM) isolated epithelial and stromal compartments of 200-day prostate xenografts. Combined initial plus secondary estrogenic exposures had the most severe tissue changes as revealed by the presence of hyperplastic glands at day 200. Gene expression changes corresponded with the cellular events in the KEGG prostate cancer pathway, indicating that initial plus secondary exposure to estrogen altered the PI3K-Akt signaling pathway, ultimately resulting in apoptosis inhibition and an increase in cell cycle progression. DNA methylation revealed that differentially methylated CpG sites significantly predominate in the stromal compartment as a result of estrogen-treatment, thereby providing new targets for future investigation. By using human fetal prostate tissue and eliminating the need for species extrapolation, this study provides novel insights into the gene expression and epigenetic effects related to prostate carcinogenesis following early life estrogen exposure. PMID:25799167

Diosgenin promotes oligodendrocyte progenitor cell differentiation through estrogen receptor-mediated ERK1/2 activation to accelerate remyelination.

PubMed

Xiao, Lin; Guo, Dazhi; Hu, Chun; Shen, Weiran; Shan, Lei; Li, Cui; Liu, Xiuyun; Yang, Wenjing; Zhang, Weidong; He, Cheng

2012-07-01

Differentiation of oligodendrocyte progenitor cells (OPCs) into mature oligodendrocytes is a prerequisite for remyelination after demyelination, and impairment of this process is suggested to be a major reason for remyelination failure. Diosgenin, a plant-derived steroid, has been implicated for therapeutic use in many diseases, but little is known about its effect on the central nervous system. In this study, using a purified rat OPC culture model, we show that diosgenin significantly and specifically promotes OPC differentiation without affecting the viability, proliferation, or migration of OPC. Interestingly, the effect of diosgenin can be blocked by estrogen receptor (ER) antagonist ICI 182780 but not by glucocorticoid and progesterone receptor antagonist RU38486, nor by mineralocorticoid receptor antagonist spirolactone. Moreover, it is revealed that both ER-alpha and ER-beta are expressed in OPC, and diosgenin can activate the extracellular signal-regulated kinase 1/2 (ERK1/2) in OPC via ER. The pro-differentiation effect of diosgenin can also be obstructed by the ERK inhibitor PD98059. Furthermore, in the cuprizone-induced demyelination model, it is demonstrated that diosgenin administration significantly accelerates/enhances remyelination as detected by Luxol fast blue stain, MBP immunohistochemistry and real time RT-PCR. Diosgenin also increases the number of mature oligodendrocytes in the corpus callosum while it does not affect the number of OPCs. Taking together, our results suggest that diosgenin promotes the differentiation of OPC into mature oligodendrocyte through an ER-mediated ERK1/2 activation pathway to accelerate remyelination, which implicates a novel therapeutic usage of this steroidal natural product in demyelinating diseases such as multiple sclerosis (MS). Copyright © 2012 Wiley Periodicals, Inc.

Ecto-nucleoside triphosphate diphosphohydrolase 3 in the ventral and lateral hypothalamic area of female rats: morphological characterization and functional implications

PubMed Central

Kiss, David S; Zsarnovszky, Attila; Horvath, Krisztina; Gyorffy, Andrea; Bartha, Tibor; Hazai, Diana; Sotonyi, Peter; Somogyi, Virag; Frenyo, Laszlo V; Diano, Sabrina

2009-01-01

Background Based on its distribution in the brain, ecto-nucleoside triphosphate diphosphohydrolase 3 (NTPDase3) may play a role in the hypothalamic regulation of homeostatic systems, including feeding, sleep-wake behavior and reproduction. To further characterize the morphological attributes of NTPDase3-immunoreactive (IR) hypothalamic structures in the rat brain, here we investigated: 1.) The cellular and subcellular localization of NTPDase3; 2.) The effects of 17β-estradiol on the expression level of hypothalamic NTPDase3; and 3.) The effects of NTPDase inhibition in hypothalamic synaptosomal preparations. Methods Combined light- and electron microscopic analyses were carried out to characterize the cellular and subcellular localization of NTPDase3-immunoreactivity. The effects of estrogen on hypothalamic NTPDase3 expression was studied by western blot technique. Finally, the effects of NTPDase inhibition on mitochondrial respiration were investigated using a Clark-type oxygen electrode. Results Combined light- and electron microscopic analysis of immunostained hypothalamic slices revealed that NTPDase3-IR is linked to ribosomes and mitochondria, is predominantly present in excitatory axon terminals and in distinct segments of the perikaryal plasma membrane. Immunohistochemical labeling of NTPDase3 and glutamic acid decarboxylase (GAD) indicated that γ-amino-butyric-acid- (GABA) ergic hypothalamic neurons do not express NTPDase3, further suggesting that in the hypothalamus, NTPDase3 is predominantly present in excitatory neurons. We also investigated whether estrogen influences the expression level of NTPDase3 in the ventrobasal and lateral hypothalamus. A single subcutaneous injection of estrogen differentially increased NTPDase3 expression in the medial and lateral parts of the hypothalamus, indicating that this enzyme likely plays region-specific roles in estrogen-dependent hypothalamic regulatory mechanisms. Determination of mitochondrial respiration rates with and without the inhibition of NTPDases confirmed the presence of NTPDases, including NTPDase3 in neuronal mitochondria and showed that blockade of mitochondrial NTPDase functions decreases state 3 mitochondrial respiration rate and total mitochondrial respiratory capacity. Conclusion Altogether, these results suggest the possibility that NTPDases, among them NTPDase3, may play an estrogen-dependent modulatory role in the regulation of intracellular availability of ATP needed for excitatory neuronal functions including neurotransmission. PMID:19383175

Merlin, the product of NF2 gene, is associated with aromatase expression and estrogen formation in human liver tissues and liver cancer cells.

PubMed

Cocciadiferro, Letizia; Miceli, Vitale; Granata, Orazia M; Carruba, Giuseppe

2017-09-01

The product of neurofibromatosis type 2 (NF2) gene, also known as Merlin/neurofibromin 2, homeostatically regulates liver stem cells by controlling abundance and signaling of epidermal growth factor receptor (EGFR), with a mechanism independent of the Hippo pathway. We have reported that locally elevated estrogen formation, driven by abnormally high expression and function of aromatase, may be implicated in development and progression of human hepatocellular carcinoma (HCC) through activation of a rapid signaling pathway mediated by amphiregulin (AREG) and EGFR. We have recently presented a model by which the aromatase-estrogen-amphiregulin-EGFR axis is activated in response to tissue injury and/or inflammatory disease, with its alteration eventually leading to development of major human tumors (liver, breast, prostate) and other chronic diseases (diabetes, obesity, Alzheimer's and heart disease). In this study, we investigated NF2 expression in liver cancer cells and tissues in relation to aromatase expression/function, estrogen receptor (ER) status and amphiregulin. Our data indicate that NF2 expression is associated with aromatase and AREG expression, being elevated in HCC tissues and HepG2 cells, intermediate in cirrhotic tissues and Huh7 cells, and lower in nontumoral liver and HA22T cells. In addition, NF2 expression is inversely related to wild type hERα66 and proportional to the expression of the membrane-associated hERα36 splice variant, as measured by exon-specific RT-PCR analysis, both in vivo and in vitro. Furthermore, incubation with estradiol induced a significant decrease of NF2 expression in both HA22T and Huh7 cells (over 54% and 22%, respectively), while no change could be observed in HepG2 cells, this effect being inversely related to aromatase expression and activity in HCC cell lines. Based on the above combined evidence, we hypothesize that NF2 behaves as a protein sensing tissue damage and aromatase-driven local estrogen formation, eventually leading to regulation of stem cells differentiation and tissue repair. Copyright © 2016 Elsevier Ltd. All rights reserved.

G Protein-Coupled Estrogen Receptor in Energy Homeostasis and Obesity Pathogenesis

PubMed Central

Shi, Haifei; Dharshan Senthil Kumar, Shiva Priya; Liu, Xian

2013-01-01

Obesity and its related metabolic diseases have reached a pandemic level worldwide. There are sex differences in the prevalence of obesity and its related metabolic diseases, with men being more vulnerable than women; however, the prevalence of these disorders increases dramatically in women after menopause, suggesting that sex steroid hormone estrogens play key protective roles against development of obesity and metabolic diseases. Estrogens are important regulators of several aspects of metabolism, including body weight and body fat, caloric intake and energy expenditure, and glucose and lipid metabolism in both males and females. Estrogens act in complex ways on their nuclear estrogen receptors (ERs) ERα and ERβ and transmembrane ERs such as G protein-coupled estrogen receptor. Genetic tools, such as different lines of knockout mouse models, and pharmacological agents, such as selective agonists and antagonists, are available to study function and signaling mechanisms of ERs. We provide an overview of the evidence for the physiological and cellular actions of ERs in estrogen-dependent processes in the context of energy homeostasis and body fat regulation and discuss its pathology that leads to obesity and related metabolic states. PMID:23317786

Efficacy of Histone Deacetylase and Estrogen Receptor Inhibition in Breast Cancer Cells Due to Concerted down Regulation of Akt

PubMed Central

Thomas, Scott; Thurn, K. Ted; Raha, Paromita; Chen, Stephanie; Munster, Pamela N.

2013-01-01

Hormonal therapy resistance remains a considerable barrier in the treatment of breast cancer. Activation of the Akt-PI3K-mTOR pathway plays an important role in hormonal therapy resistance. Our recent preclinical and clinical studies showed that the addition of a histone deacetylase inhibitor re-sensitized hormonal therapy resistant breast cancer to tamoxifen. As histone deacetylases are key regulators of Akt, we evaluated the effect of combined treatment with the histone deacetylase inhibitor PCI-24781 and tamoxifen on Akt in breast cancer cells. We demonstrate that while both histone deacetylase and estrogen receptor inhibition down regulate AKT mRNA and protein, their concerted effort results in down regulation of AKT activity with induction of cell death. Histone deacetylase inhibition exerts its effect on AKT mRNA through an estrogen receptor-dependent mechanism, primarily down regulating the most abundant isoform AKT1. Although siRNA depletion of AKT modestly induces cell death, when combined with an anti-estrogen, cytotoxicity is significantly enhanced. Thus, histone deacetylase regulation of AKT mRNA is a key mediator of this therapeutic combination and may represent a novel biomarker for predicting response to this regimen. PMID:23874830

Revisiting the timing hypothesis: Biomarkers that define the therapeutic window of estrogen for stroke

PubMed Central

Sohrabji, Farida; Selvamani, Amutha; Balden, Robyn

2012-01-01

Significantly extended life expectancy coupled with contemporary sedentary lifestyles and poor nutrition have created a global epidemic of cardiovascular disease and stroke. For women, this issue is complicated by the discrepant outcomes of hormone therapy (HT) for stroke incidence and severity as well as the therapeutic complications for stroke associated with advancing age. Here we propose that the impact of estrogen therapy cannot be considered in isolation, but should include age-related changes in endocrine, immune, and nucleic acid mediators that collaborate with estrogen to produce neuroprotective effects commonly seen in younger, healthier demographics. Due to their role as modulators of ischemic cell death, the post-stroke inflammatory response, and neuronal survival and regeneration, this review proposes that Insulin-like Growth Factor (IGF)-1, Vitamin D, and discrete members of the family of non-coding RNA peptides called microRNAs (miRNAs) may be crucial biochemical markers that help determine the neuroprotective “window” of HT. Specifically, IGF-1 confers neuroprotection in concert with, and independently of, estrogen and failure of the insulin/IGF-1 axis is associated with metabolic disturbances that increase the risk for stroke. Vitamin D and miRNAs regulate and complement IGF-1 mediated function and neuroprotective efficacy via modulation of IGF-1 availability and neural stem cell and immune cell proliferation, differentiaton and secretions. Together, age-related decline of these factors differentially affects stroke risk, severity, and outcome, and may provide a novel therapeutic adjunct to traditional HT practices. PMID:22728278

The temporal expression of estrogen receptor alpha-36 and runx2 in human bone marrow derived stromal cells during osteogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Francis, W.R., E-mail: w.francis@swansea.ac.uk; Owens, S.E.; Wilde, C.

2014-10-24

Highlights: • ERα36 is the predominant ERα isoform involved in bone regulation in human BMSC. • ERα36 mRNA is significantly upregulated during the process of osteogenesis. • The pattern of ERα36 and runx2 mRNA expression is similar during osteogenesis. • ERα36 appears to be co-localised with runx2 during osteogenesis. - Abstract: During bone maintenance in vivo, estrogen signals through estrogen receptor (ER)-α. The objectives of this study were to investigate the temporal expression of ERα36 and ascertain its functional relevance during osteogenesis in human bone marrow derived stromal cells (BMSC). This was assessed in relation to runt-related transcription factor-2 (runx2),more » a main modulatory protein involved in bone formation. ERα36 and runx2 subcellular localisation was assessed using immunocytochemistry, and their mRNA expression levels by real time PCR throughout the process of osteogenesis. The osteogenically induced BMSCs demonstrated a rise in ERα36 mRNA during proliferation followed by a decline in expression at day 10, which represents a change in dynamics within the culture between the proliferative stage and the differentiative stage. The mRNA expression profile of runx2 mirrored that of ERα36 and showed a degree subcellular co-localisation with ERα36. This study suggests that ERα36 is involved in the process of osteogenesis in BMSCs, which has implications in estrogen deficient environments.« less

Sex steroids regulate skin pigmentation through nonclassical membrane-bound receptors.

PubMed

Natale, Christopher A; Duperret, Elizabeth K; Zhang, Junqian; Sadeghi, Rochelle; Dahal, Ankit; O'Brien, Kevin Tyler; Cookson, Rosa; Winkler, Jeffrey D; Ridky, Todd W

2016-04-26

The association between pregnancy and altered cutaneous pigmentation has been documented for over two millennia, suggesting that sex hormones play a role in regulating epidermal melanocyte (MC) homeostasis. Here we show that physiologic estrogen (17β-estradiol) and progesterone reciprocally regulate melanin synthesis. This is intriguing given that we also show that normal primary human MCs lack classical estrogen or progesterone receptors (ER or PR). Utilizing both genetic and pharmacologic approaches, we establish that sex steroid effects on human pigment synthesis are mediated by the membrane-bound, steroid hormone receptors G protein-coupled estrogen receptor (GPER), and progestin and adipoQ receptor 7 (PAQR7). Activity of these receptors was activated or inhibited by synthetic estrogen or progesterone analogs that do not bind to ER or PR. As safe and effective treatment options for skin pigmentation disorders are limited, these specific GPER and PAQR7 ligands may represent a novel class of therapeutics.

Blockage of progestin physiology disrupts ovarian differentiation in XX Nile tilapia (Oreochromis niloticus)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Linyan; Luo, Feng; Fang, Xuelian

Previous studies indicated that maturation inducing hormone, 17α, 20β-Dihydroxy-4-pregnen-3-one (DHP), probably through nuclear progestin receptor (Pgr), might be involved in spermatogenesis and oogenesis in fish. To further elucidate DHP actions in teleostean ovarian differentiation, we analyzed the expression of pgr in the ovary of Nile tilapia (Oreochromis niloticus), and performed RU486 (a synthetic Pgr antagonist) treatment in XX fish from 5 days after hatching (dah) to 120dah. Tilapia Pgr was abundantly expressed in the follicular cells surrounding oocytes at 30 and 90dah. Continuous RU486 treatment led to the blockage of oogenesis and masculinization of somatic cells in XX fish. Terminationmore » of RU486 treatment and maintenance in normal condition resulted in testicular differentiation, and estrogen compensation in RU486-treated XX fish successfully restored oogenesis. In RU486-treated XX fish, transcript levels of female dominant genes were significantly reduced, while male-biased genes were evidently augmented. Meanwhile, both germ cell mitotic and meiotic markers were substantially reduced. Consistently, estrogen production levels were significantly declined in RU486-treated XX fish. Taken together, our data further proved that DHP, possibly through Pgr, might be essential in the ovarian differentiation and estrogen production in fish. - Highlights: • DHP plays a critical role in early stage oogenesis of XX tilapia. • Blockage of DHP actions by RU486 treatment led to masculinization and/or sex reversal in XX tilapia. • Both DHP and estrogen are indispensable for ovarian differentiation.« less

Transcription of CYP19A1 is directly regulated by SF-1 in the theca cells of ovary follicles in chicken.

PubMed

Wang, Jing; Gong, Yanzhang

2017-06-01

Many studies have suggested the important role of estrogen in ovarian differentiation and development of vertebrates including chicken. Cytochrome P450 aromatase, encoded by CYP19A1, is a key enzyme in estrogen synthesis, but the mechanism of CYP19A1 regulation in chicken remains unknown. Here, we found that CYP19A1 was only expressed in the theca cell layers of chicken ovary follicles. Steroidogenic factor 1 (SF-1, also named as nuclear receptor subfamily 5 group A member 1, NR5A1), a potential regulators, was expressed in both the theca cell layers and granulosa cell layers. Forkheadbox L2 (FOXL2), another potential regulator, was only expressed in the granulosa cell layers. Using luciferase assays in vitro, we found that SF-1 could activate the promoter of CYP19A1 by binding to the nuclear receptor half-site (5'-TCAAGGTCA-3') from -280 to -271 base pairs. FOXL2 did not activate the promoter of chicken CYP19A1 gene in either 293T or DF-1 cells. Overexpression of SF-1 in DF-1 cells upregulated aromatase expression, but FOXL2 could not. Taken together, our results indicated that SF-1 activates CYP19A1 mRNA expression via a conserved binding site in chicken ovary, but FOXL2 may not affect the expression of CYP19A1. Copyright © 2017 Elsevier Inc. All rights reserved.

Dynamic variation in forebrain estradiol levels during song learning

PubMed Central

Chao, Andrew; Paon, Ashley; Remage-Healey, Luke

2014-01-01

Estrogens shape brain circuits during development, and the capacity to synthesize estrogens locally has consequences for both sexual differentiation and the acute modulation of circuits during early learning. A recently-optimized method to detect and quantify fluctuations in brain estrogens in vivo provides a direct means to explore how brain estrogen production contributes to both differentiation and neuromodulation during development. Here, we use this method to test the hypothesis that neuroestrogens are sexually-differentiated as well as dynamically responsive to song tutoring (via passive video/audio playback) during the period of song learning in juvenile zebra finches. Our results show that baseline neuroestradiol levels in the caudal forebrain do not differ between males and females during an early critical masculinization window. Instead, we observe a prominent difference between males and females in baseline neuroestradiol that emerges during the subadult stage as animals approach sexual maturity. Second, we observe that fluctuating neuroestradiol levels during periods of passive song tutoring exhibit a markedly different profile in juveniles as compared to adults. Specifically, neuroestrogens in the caudal forebrain are elevated following (rather than during) tutor song exposure in both juvenile males and females, suggesting an important role for the early consolidation of tutor song memories. These results further reveal a circadian influence on the fluctuations in local neuroestrogens during sensory/cognitive tasks. Taken together, these findings uncover several unexpected features of brain estrogen synthesis in juvenile animals that may have implications for secondary masculinization as well as the consolidation of recent sensory experiences. PMID:25205304

Epidermal growth factor induces G protein-coupled receptor 30 expression in estrogen receptor-negative breast cancer cells.

PubMed

Albanito, Lidia; Sisci, Diego; Aquila, Saveria; Brunelli, Elvira; Vivacqua, Adele; Madeo, Antonio; Lappano, Rosamaria; Pandey, Deo Prakash; Picard, Didier; Mauro, Loredana; Andò, Sebastiano; Maggiolini, Marcello

2008-08-01

Different cellular receptors mediate the biological effects induced by estrogens. In addition to the classical nuclear estrogen receptors (ERs)-alpha and -beta, estrogen also signals through the seven-transmembrane G-protein-coupled receptor (GPR)-30. Using as a model system SkBr3 and BT20 breast cancer cells lacking the classical ER, the regulation of GPR30 expression by 17beta-estradiol, the selective GPR30 ligand G-1, IGF-I, and epidermal growth factor (EGF) was evaluated. Transient transfections with an expression plasmid encoding a short 5'-flanking sequence of the GPR30 gene revealed that an activator protein-1 site located within this region is required for the activating potential exhibited only by EGF. Accordingly, EGF up-regulated GPR30 protein levels, which accumulated predominantly in the intracellular compartment. The stimulatory role elicited by EGF on GPR30 expression was triggered through rapid ERK phosphorylation and c-fos induction, which was strongly recruited to the activator protein-1 site found in the short 5'-flanking sequence of the GPR30 gene. Of note, EGF activating the EGF receptor-MAPK transduction pathway stimulated a regulatory loop that subsequently engaged estrogen through GPR30 to boost the proliferation of SkBr3 and BT20 breast tumor cells. The up-regulation of GPR30 by ligand-activated EGF receptor-MAPK signaling provides new insight into the well-known estrogen and EGF cross talk, which, as largely reported, contributes to breast cancer progression. On the basis of our results, the action of EGF may include the up-regulation of GPR30 in facilitating a stimulatory role of estrogen, even in ER-negative breast tumor cells.

EFFECTS OF INCUBATION TEMPERATURE AND ESTROGEN EXPOSURE ON AROMATASE ACTIVITY IN THE BRAIN AND GONADS OF EMBRYONIC ALLIGATORS

EPA Science Inventory

During embryogenesis, incubation temperature and the hormonal environment influence gonadal differentiation of some reptiles, including all crocodilians. Current evidence suggests that aromatase, the enzyme that converts androgens to estrogens, has a role in sexual differentiatio...

Estrogen receptor-a in medial amygdala neurons regulates body weight

USDA-ARS?s Scientific Manuscript database

Estrogen receptor–a (ERa) activity in the brain prevents obesity in both males and females. However, the ERa-expressing neural populations that regulate body weight remain to be fully elucidated. Here we showed that single-minded–1 (SIM1) neurons in the medial amygdala (MeA) express abundant levels ...

Vitamin D Proliferates Vaginal Epithelium through RhoA Expression in Postmenopausal Atrophic Vagina tissue

PubMed Central

Lee, Arum; Lee, Man Ryul; Lee, Hae-Hyeog; Kim, Yeon-Suk; Kim, Jun-Mo; Enkhbold, Temuulee; Kim, Tae-Hee

2017-01-01

Postmenopausal atrophic vagina (PAV) is the thinning of the walls of the vagina and decreased lugae of the vagina. PAV is caused by decreased estrogen levels in postmenopausal women. However, the harmful effects of hormone replacement therapy (HRT) have resulted in considerable caution in its use. Various estrogen agonist treatment options are available. Vitamin D is influences the regulation of differentiation and proliferation of various cells, especially tissues lining stratified squamous epithelium, such as the vaginal epithelium. In this study, we hypothesized that vitamin D could provide an alternative and a safe treatment option for PAV by promoting the proliferation and differentiation of the vaginal epithelium. Thirty six patients were enrolled in this case-control study. Vitamin D associated proteins in a vitamin D and sex hormone treated vaginal epithelial cell line as well as normal and PAV tissues were measured. To confirm of cell-to-cell junction protein expression, cell line and tissue studies included RT-PCR, immunohistochemistry staining, and immunoblot analyses. The expression of cell-to-cell junction proteins was higher in women with symptoms of atrophic vagina tissue compared to women without the symptoms. Vitamin D stimulated the proliferation of the vaginal epithelium by activating p-RhoA and Erzin through the vitamin D receptor (VDR). The results suggest that vitamin D positively regulates cell-to-cell junction by increasing the VDR/p-RhoA/p-Ezrin pathway. This is the first study to verify the relationship of the expression of RhoA and Ezrin proteins in vaginal tissue of PAV. PMID:28843271

Vitamin D Proliferates Vaginal Epithelium through RhoA Expression in Postmenopausal Atrophic Vagina tissue.

PubMed

Lee, Arum; Lee, Man Ryul; Lee, Hae-Hyeog; Kim, Yeon-Suk; Kim, Jun-Mo; Enkhbold, Temuulee; Kim, Tae-Hee

2017-09-30

Postmenopausal atrophic vagina (PAV) is the thinning of the walls of the vagina and decreased lugae of the vagina. PAV is caused by decreased estrogen levels in postmenopausal women. However, the harmful effects of hormone replacement therapy (HRT) have resulted in considerable caution in its use. Various estrogen agonist treatment options are available. Vitamin D is influences the regulation of differentiation and proliferation of various cells, especially tissues lining stratified squamous epithelium, such as the vaginal epithelium. In this study, we hypothesized that vitamin D could provide an alternative and a safe treatment option for PAV by promoting the proliferation and differentiation of the vaginal epithelium. Thirty six patients were enrolled in this case-control study. Vitamin D associated proteins in a vitamin D and sex hormone treated vaginal epithelial cell line as well as normal and PAV tissues were measured. To confirm of cell-to-cell junction protein expression, cell line and tissue studies included RT-PCR, immunohistochemistry staining, and immunoblot analyses. The expression of cell-to-cell junction proteins was higher in women with symptoms of atrophic vagina tissue compared to women without the symptoms. Vitamin D stimulated the proliferation of the vaginal epithelium by activating p-RhoA and Erzin through the vitamin D receptor (VDR). The results suggest that vitamin D positively regulates cell-to-cell junction by increasing the VDR/p-RhoA/p-Ezrin pathway. This is the first study to verify the relationship of the expression of RhoA and Ezrin proteins in vaginal tissue of PAV.

A retinoic acid response element that overlaps an estrogen response element mediates multihormonal sensitivity in transcriptional activation of the lactoferrin gene.

PubMed

Lee, M O; Liu, Y; Zhang, X K

1995-08-01

The lactoferrin gene is highly expressed in many different tissues, and its expression is controlled by different regulators. In this report, we have defined a retinoic acid response element (RARE) in the 5'-flanking region of the lactoferrin gene promoter. The lactoferrin-RARE is composed of two AGGTCA-like motifs arranged as a direct repeat with 1-bp spacing (DR-1). A gel retardation assay demonstrated that it bound strongly with retinoid X receptor (RXR) homodimers and RXR-retinoic acid receptor (RAR) heterodimers as well as chicken ovalbumin upstream promoter transcription factor (COUP-TF) orphan receptor. In CV-1 cells, the lactoferrin-RARE linked with a heterologous thymidine kinase promoter was strongly activated by RXR homodimers in response to 9-cis-retinoic acid (9-cis-RA) but not to all-trans-RA. When the COUP-TF orphan receptor was cotransfected, the 9-cis-RA-induced RXR homodimer activity was strongly repressed. A unique feature of the lactoferrin-RARE is that it has an AGGTCA-like motif in common with an estrogen-responsive element (ERE). The composite RARE/ERE contributes to the functional interaction between retinoid receptors and the estrogen receptor (ER) and their ligands. In CV-1 cells, cotransfection of the retinoid and estrogen receptors led to mutual inhibition of the other's activity, while an RA-dependent inhibition of ER activity was observed in breast cancer cells. Furthermore, the lactoferrin-RARE/ERE showed differential transactivation activity in different cell types. RAs could activate the lactoferrin-RARE/ERE in human leukemia HL-60 cells and U937 cells but not in human breast cancer cells. By gel retardation analyses, we demonstrated that strong binding of the endogenous COUP-TF in breast cancer cells to the composite element contributed to diminished RA response in these cells. Thus, the lactoferrin-RARE/ERE functions as a signaling switch module that mediates multihormonal responsiveness in the regulation of lactoferrin gene expression.

Gene expression fingerprints of largemouth bass (Micropterus salmoides) exposed to pulp and paper mill effluents

USGS Publications Warehouse

Denslow, N.D.; Kocerha, J.; Sepulveda, M.S.; Gross, Timothy; Holm, S.E.

2004-01-01

Effluents from pulp and paper mills that historically have used elemental chlorine in the bleaching process have been implicated in inhibiting reproduction in fish. Compounds with estrogenic and androgenic binding affinities have been found in these effluents, suggesting that the impairment of reproduction is through an endocrine-related mode of action. To date, a great deal of attention has been paid to phytoestrogens and resin acids that are present in mill process streams as a result of pulping trees. Estrogen and estrogen mimics interact directly with the estrogen receptor and have near immediate effects on gene transcription by turning on the expression of a unique set of genes. Using differential display (DD) RT-PCR, we examined changes in gene expression induced by exposure to paper mill effluents. Largemouth bass were exposed to 0, 10, 20, 40, and 80% paper mill effluent concentrations in large flow-through tanks for varied periods of time including 7, 28 or 56 days. Plasma hormone levels in males and females and plasma vitellogenin (Vtg) in females decreased with dose and time. Measurements of changes in gene expression using DD RT-PCR suggest that the gene expression patterns of male fish do not change much with exposure, except for the induction of a few genes including CYP 1A, a protein that is induced through the action of the Ah receptor in response to dioxin and similar polyaromatic hydrocarbons. However, in the case of females, exposure to these effluents resulted in an up-regulation of CYP 1A that was accompanied by a generalized down-regulation of genes normally expressed during the reproductive season. These antiestrogenic changes are in agreement with previous studies in bass exposed to these effluents, and could result in decreased reproductive success in affected populations. ?? 2004 Elsevier B.V. All rights reserved.

Synergism between a half-site and an imperfect estrogen-responsive element, and cooperation with COUP-TFI are required for estrogen receptor (ER) to achieve a maximal estrogen-stimulation of rainbow trout ER gene.

PubMed

Petit, F G; Métivier, R; Valotaire, Y; Pakdel, F

1999-01-01

In all oviparous, liver represents one of the main E2-target tissues where estrogen receptor (ER) constitutes the key mediator of estrogen action. The rainbow trout estrogen receptor (rtER) gene expression is markedly up-regulated by estrogens and the sequences responsible for this autoregulation have been located in a 0.2 kb upstream transcription start site within - 40/- 248 enhancer region. Absence of interference with steroid hormone receptors and tissue-specific factors and a conserved basal transcriptional machinery between yeast and higher eukaryotes, make yeast a simple assay system that will enable determination of important cis-acting regulatory sequences within rtER gene promoter and identification of transcription factors implicated in the regulation of this gene. Deletion analysis allowed to show a synergistic effect between an imperfect estrogen-responsive element (ERE) and a consensus half-ERE to achieve a high hormone-dependent transcriptional activation of the rtER gene promoter in the presence of stably expressed rtER. As in mammalian cells, here we observed a positive regulation of the rtER gene promoter by the chicken ovalbumin upstream promoter-transcription factor I (COUP-TFI) through enhancing autoregulation. Using a point mutation COUP-TFI mutant unable to bind DNA demonstrates that enhancement of rtER gene autoregulation requires the interaction of COUP-TFI to the DNA. Moreover, this enhancement of transcriptional activation by COUP-TFI requires specifically the AF-1 transactivation function of ER and can be observed in the presence of E2 or 4-hydroxytamoxifen but not ICI 164384. Thus, this paper describes the reconstitution of a hormone-responsive transcription unit in yeast in which the regulation of rtER gene promoter could be enhanced by the participation of cis-elements and/or trans-acting factors, such as ER itself or COUP-TF.

Alkylphenol Xenoestrogens with Varying Carbon Chain Lengths Differentially and Potently Activate Signaling and Functional Responses in GH3/B6/F10 Somatomammotropes

PubMed Central

Kochukov, Mikhail Y.; Jeng, Yow-Jiun; Watson, Cheryl S.

2009-01-01

Background Alkylphenols varying in their side-chain lengths [ethyl-, propyl-, octyl-, and nonylphenol (EP, PP, OP, and NP, respectively)] and bisphenol A (BPA) represent a large group of structurally related xenoestrogens that have endocrine-disruptive effects. Their rapid nongenomic effects that depend on structure for cell signaling and resulting functions are unknown. Objectives We compared nongenomic estrogenic activities of alkylphenols with BPA and 17β-estradiol (E2) in membrane estrogen receptor-α–enriched GH3/B6/F10 pituitary tumor cells. These actions included calcium (Ca) signaling, prolactin (PRL) release, extracellular-regulated kinase (ERK) phosphorylation, and cell proliferation. Methods We imaged Ca using fura-2, measured PRL release via radioimmunoassay, detected ERK phosphorylation by fixed cell immunoassay, and estimated cell number using the crystal violet assay. Results All compounds caused increases in Ca oscillation frequency and intracellular Ca volume at 100 fM to 1 nM concentrations, although long-chain alkylphenols were most effective. All estrogens caused rapid PRL release at concentrations as low as 1 fM to 10 pM; the potency of EP, PP, and NP exceeded that of E2. All compounds at 1 nM produced similar increases in ERK phosphorylation, causing rapid peaks at 2.5–5 min, followed by inactivation and additional 60-min peaks (except for BPA). Dose–response patterns of ERK activation at 5 min were similar for E2, BPA, and PP, whereas EP caused larger effects. Only E2 and NP increased cell number. Some rapid estrogenic responses showed correlations with the hydrophobicity of estrogenic molecules; the more hydrophobic OP and NP were superior at Ca and cell proliferation responses, whereas the less hydrophobic EP and PP were better at ERK activations. Conclusions Alkylphenols are potent estrogens in evoking these nongenomic responses contributing to complex functions; their hydrophobicity can largely predict these behaviors. PMID:19479013

Global identification of genes regulated by estrogen signaling and demethylation in MCF-7 breast cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Putnik, Milica, E-mail: milica.putnik@ki.se; Zhao, Chunyan, E-mail: chunyan.zhao@ki.se; Gustafsson, Jan-Ake, E-mail: jan-ake.gustafsson@ki.se

Highlights: Black-Right-Pointing-Pointer Estrogen signaling and demethylation can both control gene expression in breast cancers. Black-Right-Pointing-Pointer Cross-talk between these mechanisms is investigated in human MCF-7 breast cancer cells. Black-Right-Pointing-Pointer 137 genes are influenced by both 17{beta}-estradiol and demethylating agent 5-aza-2 Prime -deoxycytidine. Black-Right-Pointing-Pointer A set of genes is identified as targets of both estrogen signaling and demethylation. Black-Right-Pointing-Pointer There is no direct molecular interplay of mediators of estrogen and epigenetic signaling. -- Abstract: Estrogen signaling and epigenetic modifications, in particular DNA methylation, are involved in regulation of gene expression in breast cancers. Here we investigated a potential regulatory cross-talk between thesemore » two pathways by identifying their common target genes and exploring underlying molecular mechanisms in human MCF-7 breast cancer cells. Gene expression profiling revealed that the expression of approximately 140 genes was influenced by both 17{beta}-estradiol (E2) and a demethylating agent 5-aza-2 Prime -deoxycytidine (DAC). Gene ontology (GO) analysis suggests that these genes are involved in intracellular signaling cascades, regulation of cell proliferation and apoptosis. Based on previously reported association with breast cancer, estrogen signaling and/or DNA methylation, CpG island prediction and GO analysis, we selected six genes (BTG3, FHL2, PMAIP1, BTG2, CDKN1A and TGFB2) for further analysis. Tamoxifen reverses the effect of E2 on the expression of all selected genes, suggesting that they are direct targets of estrogen receptor. Furthermore, DAC treatment reactivates the expression of all selected genes in a dose-dependent manner. Promoter CpG island methylation status analysis revealed that only the promoters of BTG3 and FHL2 genes are methylated, with DAC inducing demethylation, suggesting DNA methylation directs repression of these genes in MCF-7 cells. In a further analysis of the potential interplay between estrogen signaling and DNA methylation, E2 treatment showed no effect on the methylation status of these promoters. Additionally, we show that the ER{alpha} recruitment occurs at the FHL2 promoter in an E2- and DAC-independent fashion. In conclusion, we identified a set of genes regulated by both estrogen signaling and DNA methylation. However, our data does not support a direct molecular interplay of mediators of estrogen and epigenetic signaling at promoters of regulated genes.« less

Estrogen enhances mismatch repair by induction of MLH1 expression via estrogen receptor-β

PubMed Central

Lu, Jun-Yu; Jin, Peng; Gao, Wei; Wang, De-Zhi; Sheng, Jian-Qiu

2017-01-01

Epidemiological data demonstrated that hormone replace treatment has protective effect against colorectal cancer (CRC). Our previous studies showed that this effect may be associated with DNA mismatch repair. This study aims to investigate the mechanism of estrogen induction of MLH1, and whether colorectal tumor proliferation can be inhibited through induction of MLH1 by estrogen signal pathway. Human CRC cell lines were used to examine the regulation of MLH1 expression by over-expression and depletion of estrogen receptor-α (ERα) and estrogen receptor-β (ERβ), under the treatment with 17β-estradiol or β-Estradiol 6-(O-carboxy-methyl)oxime:BSA, followed by a real-time Q-PCR and Western blotting analysis. Luciferase reporter and chromatin immunoprecipitation assays were used to identify the estrogen response elements in the proximal promoter of MLH1 gene. Then, the influence of estrogen-induced MLH1 on CRC tumor growth were determined in vitro and in vivo. We found that mismatch repair ability and microsatellite stability of cells were enhanced by estrogen via induction of MLH1 expression, which was mediated by ERβ, through a transcriptional activation process. Furthermore, we identified that ERβ exerted an inhibitory effect on CRC tumor proliferation in vitro and in vivo, combined with 5-FU, through up-regulation of MLH1 expression. Finally, we concluded that estrogen enhances mismatch repair ability and tumor inhibition effect in vitro and in vivo, via induction of MLH1 expression mediated by ERβ. PMID:28404976

Estrogen enhances mismatch repair by induction of MLH1 expression via estrogen receptor-β.

PubMed

Lu, Jun-Yu; Jin, Peng; Gao, Wei; Wang, De-Zhi; Sheng, Jian-Qiu

2017-06-13

Epidemiological data demonstrated that hormone replace treatment has protective effect against colorectal cancer (CRC). Our previous studies showed that this effect may be associated with DNA mismatch repair. This study aims to investigate the mechanism of estrogen induction of MLH1, and whether colorectal tumor proliferation can be inhibited through induction of MLH1 by estrogen signal pathway. Human CRC cell lines were used to examine the regulation of MLH1 expression by over-expression and depletion of estrogen receptor-α (ERα) and estrogen receptor-β (ERβ), under the treatment with 17β-estradiol or β-Estradiol 6-(O-carboxy-methyl)oxime:BSA, followed by a real-time Q-PCR and Western blotting analysis. Luciferase reporter and chromatin immunoprecipitation assays were used to identify the estrogen response elements in the proximal promoter of MLH1 gene. Then, the influence of estrogen-induced MLH1 on CRC tumor growth were determined in vitro and in vivo. We found that mismatch repair ability and microsatellite stability of cells were enhanced by estrogen via induction of MLH1 expression, which was mediated by ERβ, through a transcriptional activation process. Furthermore, we identified that ERβ exerted an inhibitory effect on CRC tumor proliferation in vitro and in vivo, combined with 5-FU, through up-regulation of MLH1 expression. Finally, we concluded that estrogen enhances mismatch repair ability and tumor inhibition effect in vitro and in vivo, via induction of MLH1 expression mediated by ERβ.

Estrogenic involvement in social learning, social recognition and pathogen avoidance.

PubMed

Choleris, Elena; Clipperton-Allen, Amy E; Phan, Anna; Valsecchi, Paola; Kavaliers, Martin

2012-04-01

Sociality comes with specific cognitive skills that allow the proper processing of information about others (social recognition), as well as of information originating from others (social learning). Because sociality and social interactions can also facilitate the spread of infection among individuals the ability to recognize and avoid pathogen threat is also essential. We review here various studies primarily from the rodent literature supporting estrogenic involvement in the regulation of social recognition, social learning (socially acquired food preferences and mate choice copying) and the recognition and avoidance of infected and potentially infected individuals. We consider both genomic and rapid estrogenic effects involving estrogen receptors α and β, and G-protein coupled estrogen receptor 1, along with their interactions with neuropeptide systems in the processing of social stimuli and the regulation and expression of these various socially relevant behaviors. Copyright © 2012 Elsevier Inc. All rights reserved.

G protein-coupled receptor 30 expression is up-regulated by EGF and TGF alpha in estrogen receptor alpha-positive cancer cells.

PubMed

Vivacqua, Adele; Lappano, Rosamaria; De Marco, Paola; Sisci, Diego; Aquila, Saveria; De Amicis, Francesca; Fuqua, Suzanne A W; Andò, Sebastiano; Maggiolini, Marcello

2009-11-01

In the present study, we evaluated the regulation of G protein-coupled receptor (GPR)30 expression in estrogen receptor (ER)-positive endometrial, ovarian, and estrogen-sensitive, as well as tamoxifen-resistant breast cancer cells. We demonstrate that epidermal growth factor (EGF) and TGF alpha transactivate the GPR30 promoter and accordingly up-regulate GPR30 mRNA and protein levels only in endometrial and tamoxifen-resistant breast cancer cells. These effects exerted by EGF and TGF alpha were dependent on EGF receptor (EGFR) expression and activation and involved phosphorylation of the Tyr(1045) and Tyr(1173) EGFR sites. Using gene-silencing experiments and specific pharmacological inhibitors, we have ascertained that EGF and TGF alpha induce GPR30 expression through the EGFR/ERK transduction pathway, and the recruitment of c-fos to the activator protein-1 site located within GPR30 promoter sequence. Interestingly, we show that functional cross talk of GPR30 with both activated EGFR and ER alpha relies on a physical interaction among these receptors, further extending the potential of estrogen to trigger a complex stimulatory signaling network in hormone-sensitive tumors. Given that EGFR/HER2 overexpression is associated with tamoxifen resistance, our data may suggest that ligand-activated EGFR could contribute to the failure of tamoxifen therapy also by up-regulating GPR30, which in turn could facilitates the action of estrogen. In addition, important for resistance is the ability of tamoxifen to bind to and activate GPR30, the expression of which is up-regulated by EGFR activation. Our results emphasize the need for new endocrine agents able to block widespread actions of estrogen without exerting any stimulatory activity on transduction pathways shared by the steroid and growth factor-signaling networks.

Adipose Estrogen and Increased Breast Cancer Risk in Obesity: Regulation by Leptin and Insulin

DTIC Science & Technology

2007-09-07

enzyme aromatase which catalyses the biosynthesis of estrogen from androgen and also 17-beta- hydroxysteroid dehydrogenase (17- beta HSD) important for...biosynthesis of estrogen from androgen and also 17-β- hydroxysteroid dehydrogenase (17-βHSD) important for the conversion of estrone to estradiol. In

Soy Glyceollins Regulate Transcript Abundance in the Female Mouse Brain

USDA-ARS?s Scientific Manuscript database

Glyceollins (Gly), produced by soy plants in response to stress, have anti-estrogenic activity in breast and ovarian cancer cell lines in vitro and in vivo. In addition to known anti-estrogenic effects, Gly exhibits mechanisms of action not involving estrogen receptor (ER) signaling. To date, effect...

Genistein versus ICI 182, 780: an ally or enemy in metastatic progression of prostate cancer.

PubMed

Nakamura, Hisae; Wang, Yuwei; Xue, Hui; Romanish, Mark T; Mager, Dixie L; Helgason, Cheryl D; Wang, Yuzhuo

2013-12-01

Androgen signalling through the androgen receptor (AR) plays a critical role in prostate cancer (PCa) initiation and progression. Estrogen in synergy with androgen is essential for cell growth of the normal and malignant prostate. However, the exact role that estrogen and the estrogen receptor play in prostate carcinogenesis remains unclear. We have previously demonstrated the metastasis-promoting effect of an estrogen receptor beta (ERβ) agonist (genistein) in a patient-derived PCa xenograft model mimicking localized and metastatic disease. To test the hypothesis that the tumor-promoting activity of genistein was due to its estrogenic properties, we treated the xenograft-bearing mice with genistein and an anti-estrogen compound (ICI 182, 780) and compared the differential gene expression using microarrays. Using a second xenograft model which was derived from another patient, we showed that genistein promoted disease progression in vivo and ICI 182, 780 inhibited metastatic spread. The microarray analysis revealed that the metallothionein (MT) gene family was differentially expressed in tumors treated by these compounds. Using qRT-PCR, the differences in expression levels were validated in the metastatic and non-metastatic LTL313 PCa xenograft tumor lines, both of which were originally derived from the same PCa patient. Together our data provide evidence that genistein stimulates and ICI 182, 780 inhibits metastatic progression, suggesting that these effects may be mediated by ERβ signalling. © 2013 Wiley Periodicals, Inc.

Induction of osteoblast differentiation by selective activation of kinase-mediated actions of the estrogen receptor.

PubMed

Kousteni, Stavroula; Almeida, Maria; Han, Li; Bellido, Teresita; Jilka, Robert L; Manolagas, Stavros C

2007-02-01

Estrogens control gene transcription by cis or trans interactions of the estrogen receptor (ER) with target DNA or via the activation of cytoplasmic kinases. We report that selective activation of kinase-mediated actions of the ER with 4-estren-3alpha,17beta-diol (estren) or an estradiol-dendrimer conjugate, each a synthetic compound that stimulates kinase-mediated ER actions 1,000 to 10,000 times more potently than direct DNA interactions, induced osteoblastic differentiation in established cell lines of uncommitted osteoblast precursors and primary cultures of osteoblast progenitors by stimulating Wnt and BMP-2 signaling in a kinase-dependent manner. In sharp contrast, 17beta-estradiol (E(2)) suppressed BMP-2-induced osteoblast progenitor commitment and differentiation. Consistent with the in vitro findings, estren, but not E(2), stimulated Wnt/beta-catenin-mediated transcription in T-cell factor-lacZ transgenic mice. Moreover, E(2) stimulated BMP signaling in mice in which ERalpha lacks DNA binding activity and classical estrogen response element-mediated transcription (ERalpha(NERKI/-)) but not in wild-type controls. This evidence reveals for the first time the existence of a large signalosome in which inputs from the ER, kinases, bone morphogenetic proteins, and Wnt signaling converge to induce differentiation of osteoblast precursors. ER can either induce it or repress it, depending on whether the activating ligand (and presumably the resulting conformation of the receptor protein) precludes or accommodates ERE-mediated transcription.

Estrogen regulation of gene expression in the teleost fish immune system.

PubMed

Burgos-Aceves, Mario Alberto; Cohen, Amit; Smith, Yoav; Faggio, Caterina

2016-11-01

Elucidating the mechanisms of estrogens-induced immunomodulation in teleost fish is of great importance due to the observed worldwide continuing decrease in pristine environments. However, little is know about the immunotoxicological consequences of exposure to these chemicals in fish, or of the mechanisms through which these effects are mediated. In this review, we summarize the results showing estrogens (natural or synthetic) acting through estrogen receptors and regulating specific target genes, also through microRNAs (miRNAs), leading to modulation of the immune functioning. The identification and characterization of miRNAs will provide new opportunities for functional genome research on teleost immune system and can also be useful when screening for novel molecule biomarkers for environmental pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

A calixpyrrole derivative acts as an antagonist to GPER, a G-protein coupled receptor: mechanisms and models.

PubMed

Lappano, Rosamaria; Rosano, Camillo; Pisano, Assunta; Santolla, Maria Francesca; De Francesco, Ernestina Marianna; De Marco, Paola; Dolce, Vincenza; Ponassi, Marco; Felli, Lamberto; Cafeo, Grazia; Kohnke, Franz Heinrich; Abonante, Sergio; Maggiolini, Marcello

2015-10-01

Estrogens regulate numerous pathophysiological processes, mainly by binding to and activating estrogen receptor (ER)α and ERβ. Increasing amounts of evidence have recently demonstrated that G-protein coupled receptor 30 (GPR30; also known as GPER) is also involved in diverse biological responses to estrogens both in normal and cancer cells. The classical ER and GPER share several features, including the ability to bind to identical compounds; nevertheless, some ligands exhibit opposed activity through these receptors. It is worth noting that, owing to the availability of selective agonists and antagonists of GPER for research, certain differential roles elicited by GPER compared with ER have been identified. Here, we provide evidence on the molecular mechanisms through which a calixpyrrole derivative acts as a GPER antagonist in different model systems, such as breast tumor cells and cancer-associated fibroblasts (CAFs) obtained from breast cancer patients. Our data might open new perspectives toward the development of a further class of selective GPER ligands in order to better dissect the role exerted by this receptor in different pathophysiological conditions. Moreover, calixpyrrole derivatives could be considered in future anticancer strategies targeting GPER in cancer cells. © 2015. Published by The Company of Biologists Ltd.

Environmental sex determination mechanisms in reptiles.

PubMed

Merchant-Larios, H; Díaz-Hernández, V

2013-01-01

Temperature-dependent sex determination (TSD) was first discovered in reptiles. Since then, a great diversity of sex-determining responses to temperature has been reported. Higher temperatures can produce either males or females, and the temperature ranges and lengths of exposure that influence TSD are remarkably variable among species. In addition, transitory gene regulatory networks leading to gonadal TSD have evolved. Although most genes involved in gonadal development are conserved in vertebrates, including TSD species, temporal and spatial gene expression patterns vary among species. Despite variation in TSD pattern and gene expression heterochrony, the structural framework, the medullary cords, and cortex of the bipotential gonad have been strongly conserved. Aromatase (CYP19), which regulates gonadal estrogen levels, is proposed to be the main target of a putative thermosensitive factor for TSD. However, manipulation of estrogen levels rarely mimics the precise timing of temperature effects on expression of gonadal genes, as occurs with TSD. Estrogen levels may influence sex determination or gonad differentiation depending on the species. Furthermore, the process leading to sex determination under the influence of temperature poses problems that are not encountered by species with genetic sex determination. Yolk steroids of maternal origin and steroids produced by the embryonic nervous system should also be considered as sources of hormones that may play a role in TSD. Copyright © 2012 S. Karger AG, Basel.

G protein-coupled estrogen receptor (GPER) expression in normal and abnormal endometrium.

PubMed

Plante, Beth J; Lessey, Bruce A; Taylor, Robert N; Wang, Wei; Bagchi, Milan K; Yuan, Lingwen; Scotchie, Jessica; Fritz, Marc A; Young, Steven L

2012-07-01

Rapid estrogen effects are mediated by membrane receptors, and evidence suggests a role for both a membrane-associated form of estrogen receptor alpha (ESR1; ERα) and G-protein coupled receptor 30 (GPER; GPR30). Considering estrogen's importance in endometrial physiology and endometriosis pathophysiology, we hypothesized that GPER could be involved in both cyclic changes in endometrial estrogen action and that aberrant expression might be seen in the eutopic endometrium of women with endometriosis. Using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemical analysis of normal endometrium, endometrial samples demonstrated cycle-regulated expression of GPER, with maximal expression in the proliferative phase. Eutopic and ectopic endometrium from women with endometriosis overexpressed GPER as compared to eutopic endometrium of normal participants. Ishikawa cells, an adenocarcinoma cell line, expressed GPER, with increased expression upon treatment with estrogen or an ESR1 agonist, but not with a GPER-specific agonist. Decreased expression was seen in Ishikawa cells stably transfected with progesterone receptor A. Together, these data suggest that normal endometrial GPER expression is cyclic and regulated by nuclear estrogen and progesterone receptors, while expression is dysregulated in endometriosis.

Differential gene expression patterns in developing sexually dimorphic rat brain regions exposed to antiandrogenic, estrogenic, or complex endocrine disruptor mixtures: glutamatergic synapses as target.

PubMed

Lichtensteiger, Walter; Bassetti-Gaille, Catherine; Faass, Oliver; Axelstad, Marta; Boberg, Julie; Christiansen, Sofie; Rehrauer, Hubert; Georgijevic, Jelena Kühn; Hass, Ulla; Kortenkamp, Andreas; Schlumpf, Margret

2015-04-01

The study addressed the question whether gene expression patterns induced by different mixtures of endocrine disrupting chemicals (EDCs) administered in a higher dose range, corresponding to 450×, 200×, and 100× high-end human exposure levels, could be characterized in developing brain with respect to endocrine activity of mixture components, and which developmental processes were preferentially targeted. Three EDC mixtures, A-Mix (anti-androgenic mixture) with 8 antiandrogenic chemicals (di-n-butylphthalate, diethylhexylphthalate, vinclozolin, prochloraz, procymidone, linuron, epoxiconazole, and DDE), E-Mix (estrogenic mixture) with 4 estrogenic chemicals (bisphenol A, 4-methylbenzylidene camphor, 2-ethylhexyl 4-methoxycinnamate, and butylparaben), a complex mixture, AEP-Mix, containing the components of A-Mix and E-Mix plus paracetamol, and paracetamol alone, were administered by oral gavage to rat dams from gestation day 7 until weaning. General developmental endpoints were not affected by EDC mixtures or paracetamol. Gene expression was analyzed on postnatal day 6, during sexual brain differentiation, by exon microarray in medial preoptic area in the high-dose group, and by real-time RT-PCR in medial preoptic area and ventromedial hypothalamus in all dose groups. Expression patterns were mixture, sex, and region specific. Effects of the analgesic drug paracetamol, which exhibits antiandrogenic activity in peripheral systems, differed from those of A-Mix. All mixtures had a strong, mixture-specific impact on genes encoding for components of excitatory glutamatergic synapses and genes controlling migration and pathfinding of glutamatergic and GABAergic neurons, as well as genes linked with increased risk of autism spectrum disorders. Because development of glutamatergic synapses is regulated by sex steroids also in hippocampus, this may represent a general target of ECD mixtures.

Estrogen-dependent downregulation of hairy and enhancer of split homolog-1 gene expression in breast cancer cells is mediated via a 3' distal element.

PubMed

Müller, Patrick; Merrell, Kenneth W; Crofts, Justin D; Rönnlund, Caroline; Lin, Chin-Yo; Gustafsson, Jan-Ake; Ström, Anders

2009-03-01

Regulation of hairy and enhancer of split homologue-1 (HES-1) by estradiol and all-trans retinoic acid affects proliferation of human breast cancer cells. Here, we identify and characterize cis-regulatory elements involved in HES-1 regulation. In the distal 5' promoter of the HES-1 gene, we found a retinoic acid response element and in the distal 3' region, an estrogen receptor alpha(ER)alpha binding site. The ERalpha binding site, composed of an estrogen response element (ERE) and an ERE half-site, is important for both ERalpha binding and transcriptional regulation. Chromatin immunoprecipitation assays revealed that ERalpha is recruited to the ERE and associates with the HES-1 promoter. We also show recruitment of nuclear receptor co-regulators to the ERE in response to estradiol, followed by a decrease in histone acetylation and RNA polymerase II docking in the HES-1 promoter region. Our findings are consistent with a novel type of repressive estrogen response element in the distal 3' region of the HES-1 gene.

Luminal lncRNAs Regulation by ERα-Controlled Enhancers in a Ligand-Independent Manner in Breast Cancer Cells

PubMed Central

Miano, Valentina; Rosti, Valentina; Manitta, Eleonora; Elhasnaoui, Jamal; Basile, Giulia

2018-01-01

Estrogen receptor-α (ERα) is a ligand-inducible protein which mediates estrogenic hormones signaling and defines the luminal BC phenotype. Recently, we demonstrated that even in absence of ligands ERα (apoERα) binds chromatin sites where it regulates transcription of several protein-coding and lncRNA genes. Noteworthy, apoERα-regulated lncRNAs marginally overlap estrogen-induced transcripts, thus representing a new signature of luminal BC genes. By the analysis of H3K27ac enrichment in hormone-deprived MCF-7 cells, we defined a set of Super Enhancers (SEs) occupied by apoERα, including one mapped in proximity of the DSCAM-AS1 lncRNA gene. This represents a paradigm of apoERα activity since its expression is largely unaffected by estrogenic treatment, despite the fact that E2 increases ERα binding on DSCAM-AS1 promoter. We validated the enrichment of apoERα, p300, GATA3, FoxM1 and CTCF at both DSCAM-AS1 TSS and at its associated SE by ChIP-qPCR. Furthermore, by analyzing MCF-7 ChIA-PET data and by 3C assays, we confirmed long range chromatin interaction between the SE and the DSCAM-AS1 TSS. Interestingly, CTCF and p300 binding showed an enrichment in hormone-depleted medium and in the presence of ERα, elucidating the dynamics of the estrogen-independent regulation of DSCAM-AS1 expression. The analysis of this lncRNA provides a paradigm of transcriptional regulation of a luminal specific apoERα regulated lncRNA. PMID:29462945

Identification of an estrogen response element in the 3'-flanking region of the murine c-fos protooncogene.

PubMed

Hyder, S M; Stancel, G M; Nawaz, Z; McDonnell, D P; Loose-Mitchell, D S

1992-09-05

We have used transient transfection assays with reporter plasmids expressing chloramphenicol acetyltransferase, linked to regions of mouse c-fos, to identify a specific estrogen response element (ERE) in this protooncogene. This element is located in the untranslated 3'-flanking region of the c-fos gene, 5 kilobases (kb) downstream from the c-fos promoter and 1.5 kb downstream of the poly(A) signal. This element confers estrogen responsiveness to chloramphenicol acetyltransferase reporters linked to both the herpes simplex virus thymidine kinase promoter and the homologous c-fos promoter. Deletion analysis localized the response element to a 200-base pair fragment which contains the element GGTCACCACAGCC that resembles the consensus ERE sequence GGTCACAGTGACC originally identified in Xenopus vitellogenin A2 gene. A synthetic 36-base pair oligodeoxynucleotide containing this c-fos sequence conferred estrogen inducibility to the thymidine kinase promoter. The corresponding sequence also induced reporter activity when present in the c-fos gene fragment 3 kb from the thymidine kinase promoter. Gel-shift experiments demonstrated that synthetic oligonucleotides containing either the consensus ERE or the c-fos element bind human estrogen receptor obtained from a yeast expression system. However, the mobility of the shifted band is faster for the fos-ERE-complex than the consensus ERE complex suggesting that the three-dimensional structure of the protein-DNA complexes is different or that other factors are differentially involved in the two reactions. When the 5'-GGTCA sequence present in the c-fos ERE is mutated to 5'-TTTCA, transcriptional activation and receptor binding activities are both lost. Mutation of the CAGCC-3' element corresponding to the second half-site of the c-fos sequence also led to the loss of receptor binding activity, suggesting that both half-sites of this element are involved in this function. The estrogen induction mediated by either the c-fos or the consensus ERE was blunted by the antiestrogen tamoxifen. Based on these studies, we believe the 3'-fos ERE sequence we have identified may be a major cis-acting element involved in the physiological regulation of the gene by estrogens in vivo.

Microsomal receptor for steroid hormones: functional implications for nuclear activity.

PubMed

Muldoon, T G; Watson, G H; Evans, A C; Steinsapir, J

1988-01-01

Target tissues for steroid hormones are responsive by virtue of and to the extent of their content of functional intracellular receptors. Recent years have seen a shift in considerations of the cellular dynamics and distribution of these receptors, with current views favoring predominant intranuclear localization in the intact cell. This paper summarizes our analyses of the microsomal estrogen and androgen binding capability of rat uterine and ventral prostate tissue, respectively; these studies have revealed a set of high affinity sites that may act as a conduit for estrogen traversing the cell en route to the nucleus. These sites have many properties in common with cytosolic receptors, with the salient difference of a failure to activate to a more avid DNA-binding form under conditions which permit such activation of cytosolic receptors. The microsomal estrogen-binding proteins also have appreciable affinity for progesterone, another distinction from other known cellular estrogen receptor species. Various experimental approaches were employed to demonstrate that the microsomal receptors were not simply cytosol contaminants; the most convincing evidence is the recent successful separation of the cytosolic and microsomal forms by differential ammonium sulfate precipitation. Discrete subfractionation of subcellular components on successive sucrose gradients, with simultaneous assessments of binding capability and marker enzyme concentrations, indicates that the major portion of the binding is localized within the vesicles of the endoplasmic reticulum free of significant plasma membrane contamination. The microsomal receptors are readily solubilized by extraction with high- or low-salt-containing buffers or with steroid. The residual microsomes following such extraction have the characteristics of saturable acceptor sites for cytosolic estrogen-receptor complexes. The extent to which these sites will accept the cytosolic complexes is equal to the concentration of microsomal binding sites extracted. These observations suggest three possible roles for the microsomal receptor-like proteins: (a) modulation of estrogen access to nuclear binding sites; (b) formation of functional complexes which diffuse to other extranuclear sites to alter non-genomic cellular processes; (c) regulation of nuclear concentration of estrogen-receptor complexes by virtue of producing microsomal acceptor sites for uptake of free or loosely associated nuclear complexes, previously thought to exist in the cytoplasm.

Effects of bisphenol A (BPA) on brain-specific expression of cyp19a1b gene in swim-up fry of Labeo rohita.

PubMed

Gupta, Shreyasi; Guha, Payel; Majumder, Suravi; Pal, Puja; Sen, Koushik; Chowdhury, Piyali; Chakraborty, Arindam; Panigrahi, Ashis Kumar; Mukherjee, Dilip

2018-07-01

Estrogen regulates numerous developmental and physiological processes and effects are mediated mainly by estrogenic receptors (ERs), which function as ligand-regulated transcription factor. ERs can be activated by many different types endocrine disrupting chemicals (EDCs) and interfere with behaviour and reproductive potential of living organism. Estrogenic regulation of membrane associated G protein-coupled estrogen receptor, GPER activity has also been reported. Bisphenol A (BPA), a ubiquitous endocrine disruptor is present in many household products, has been linked to many adverse effect on sexual development and reproductive potential of wild life species. The present work is aimed to elucidate how an environmentally pervasive chemical BPA affects in vivo expression of a known estrogen target gene, cyp19a1b in the brain, and a known estrogenic biomarker, vitellogenin (Vg) in the whole body homogenate of 30 days post fertilization (dpf) swim-up fry of Labeo rohita. We confirm that, like estrogen, the xenoestrogen BPA exposure for 5-15 days induces strong overexpression of cyp19a1b, but not cyp19a1a mRNA in the brain and increase concentration of vitellogenin in swim-up fry. BPA also induces strong overexpression of aromatase B protein and aromatase activity in brain. Experiments using selective modulators of classical ERs and GPER argue that this induction is largely through nuclear ERs, not through GPER. Thus, BPA has the potential to elevate the levels of aromatase and thereby, levels of endogenous estrogen in developing brain. These results indicate that L. rohita swim-up fry can be used to detect environmental endocrine disruptors either using cyp19a1b gene expression or vitellogenin induction. Copyright © 2018 Elsevier Inc. All rights reserved.

Gene expression profiling in Ishikawa cells: A fingerprint for estrogen active compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boehme, Kathleen; Simon, Stephanie; Mueller, Stefan O.

2009-04-01

Several anthropogenous and naturally occurring substances, referred to as estrogen active compounds (EACs), are able to interfere with hormone and in particular estrogen receptor signaling. EACs can either cause adverse health effects in humans and wildlife populations or have beneficial effects on estrogen-dependent diseases. The aim of this study was to examine global gene expression profiles in estrogen receptor (ER)-proficient Ishikawa plus and ER-deficient Ishikawa minus endometrial cancer cells treated with selected well-known EACs (Diethylstilbestrol, Genistein, Zearalenone, Resveratrol, Bisphenol A and o,p'-DDT). We also investigated the effect of the pure antiestrogen ICI 182,780 (ICI) on the expression patterns caused bymore » these compounds. Transcript levels were quantified 24 h after compound treatment using Illumina BeadChip Arrays. We identified 87 genes with similar expression changes in response to all EAC treatments in Ishikawa plus. ICI lowered the magnitude or reversed the expression of these genes, indicating ER dependent regulation. Apart from estrogenic gene regulation, Bisphenol A, o,p'-DDT, Zearalenone, Genistein and Resveratrol displayed similarities to ICI in their expression patterns, suggesting mixed estrogenic/antiestrogenic properties. In particular, the predominant antiestrogenic expression response of Resveratrol could be clearly distinguished from the other test compounds, indicating a distinct mechanism of action. Divergent gene expression patterns of the phytoestrogens, as well as weaker estrogenic gene expression regulation determined for the anthropogenous chemicals Bisphenol A and o,p'-DDT, warrants a careful assessment of potential detrimental and/or beneficial effects of EACs. The characteristic expression fingerprints and the identified subset of putative marker genes can be used for screening chemicals with an unknown mode of action and for predicting their potential to exert endocrine disrupting effects.« less

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...

THE USE OF GENE ARRAYS TO DETERMINE TEMPORAL GENE INDUCTION IN SHEEPSHEAD MINNOWS EXPOSED TO E2

EPA Science Inventory

Gene arrays provide a means to study differential gene expression in fish exposed to environmental estrogens by providing a "snapshot" of the genes expressed at a given time. Such array data may also uncover previously unknown biochemical pathways affected by estrogenic compounds...

Differential effects of estrogen and progestin on apolipoprotein B100 and B48 kinetics in postmenopausal women

USDA-ARS?s Scientific Manuscript database

The distinct effects of the estrogen and progestin components of hormonal therapy on the metabolism of apolipoprotein (apo) B-containing lipoproteins have not been studied. We enrolled eight healthy postmenopausal women in a placebo-controlled, randomized, double-blind, crossover study. Each subject...

Single Chain Antibodies as Estrogen Receptor Repressors in Breast Cancer

DTIC Science & Technology

2000-06-01

differential display we identified proteinase inhibitor-9 as an mRNA upregulated by estrogen in a human hepatoblastoma cell line (HepG2) stably transfected...antiestrogen ICI 182,780 was a pure antag- human hepatoblastoma cell line (3), contained ER (4), this cell onist. Western blot analysis showed that

Early-life estrogen exposure and uterine pathogenesis: ?A model for gene-environment interactions

EPA Science Inventory

Aberrant cellular differentiation early in life can contribute to increased cancer risk later in life. In a classic model of this effect, female mice exposed on postnatal day (PND) 1-5 to the synthetic estrogen diethylstilbestrol (DES) have a high incidence of uterine carcinoma. ...

Identification of the G protein-coupled estrogen receptor (GPER) in human prostate: expression site of the estrogen receptor in the benign and neoplastic gland.

PubMed

Rago, V; Romeo, F; Giordano, F; Ferraro, A; Carpino, A

2016-01-01

Estrogens are involved in growth, differentiation and pathogenesis of human prostate through the mediation of the classical estrogen receptors ERα and ERβ. The G protein-coupled estrogen receptor (GPER) is a 'novel' mediator of estrogen signaling which has been recently recognized in some human reproductive tissues, but its expression in the prostate gland is still unknown. Here, we investigated GPER in benign (from 5 patients) and neoplastic prostatic tissues (from 50 patients) by immunohistochemical analysis and Western blotting. Normal areas of benign prostates revealed a strong GPER immunoreactivity in the basal epithelial cells while luminal epithelial cells were unreactive and stromal cells were weakly immunostained. GPER was also immunolocalized in adenocarcinoma samples but the immunoreactivity of tumoral areas decreased from Gleason pattern 2 to Gleason pattern 4. Furthermore, a strong GPER immunostaining was also revealed in cells of pre-neoplastic lesions (high-grade prostatic intra-epithelial neoplasia). Western blot analysis of benign and tumor protein extracts showed the presence of a ~42 kDa band, consistent with the GPER molecular weight. An increase in both pAkt and p cAMP-response-binding protein (pCREB) levels was also observed in poorly differentiated PCa samples. Finally, this work identified GPER in the epithelial basal cells of benign human prostate, with a different localization with respect to the classical estrogen receptors. Furthermore, the expression of GPER in prostatic adenocarcinoma cells was also observed but with a modulation of the immunoreactivity according to tumor cell arrangements. © 2015 American Society of Andrology and European Academy of Andrology.

Glyceollin, a novel regulator of mTOR/p70S6 in estrogen receptor positive breast cancer

USDA-ARS?s Scientific Manuscript database

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...

GPR30: a novel therapeutic target in estrogen-related disease.

PubMed

Prossnitz, Eric R; Sklar, Larry A; Oprea, Tudor I; Arterburn, Jeffrey B

2008-03-01

Estrogen is a crucial hormone in human physiology that regulates a multitude of biological processes. It is also an important target in many diseases such as cancer and skeletal, neurological and immunological conditions. The actions of estrogen have traditionally been ascribed to one of two closely related classical nuclear hormone receptors, ERalpha and ERbeta, which are best characterized for regulating gene expression. Recent studies have revealed the contribution of a novel estrogen receptor GPR30, which belongs to the family of seven-transmembrane G-protein-coupled receptors, to many of the rapid biological responses to estrogen. Many drugs, such as tamoxifen and fulvestrant, which seem to selectively inhibit the activities of the classical estrogen receptors, are in widespread clinical use. However, recent results indicate that these same drugs activate multiple cellular-signaling pathways via GPR30. Unraveling the pharmacological profiles and specificities of ERalpha, ERbeta and GPR30 will be vital for understanding not only the physiological roles of each receptor but also for the development of the next generation of receptor-specific drugs.

EF24 prevents rotenone-induced estrogenic status alteration in breast cancer.

PubMed

Roy, Debarshi; Kabiraj, Parijat; Pal, Rituraj

2014-04-01

Protein disulfide isomerase (PDI), an important endoplasmic reticulum-resident oxidoreductase chaperone can bind to estrogens as well as intact with its receptor proteins [i.e. estrogen receptors (ER) α and β]. It has been postulated that PDI also acts as an intracellular 17β-estradiol (E2)-binding protein that transports and accumulates E2 in live cells. Drop in E2 level promotes dissociation of E2 from PDI and released in cytosol; the released E2 can augment estrogen receptor-mediated transcriptional activity and mitogenic action in cultured cells by modulating the ERβ/ERα ratio. In this study, we observed rotenone-induced damage to PDI leads to significant increase in ERβ/ERα ratio by down-regulating ERα and up-regulating ERβ. We demonstrated that nitrosative stress induced disruption of the cellular estrogenic status can be prevented through diphenyl difluoroketone (EF24, curcumin analog) intervention by protecting PDI from reactive oxygen species (ROS)-induced damage. Together, our study suggests that both PDI and EF24 can play a vital role in maintaining cellular estrogenic homeostasis. © 2013 International Federation for Cell Biology.

[Simulated uterus microenvironment induced human placental mesenchymal stem cells differentiation to uterus smooth muscle cells in vitro].

PubMed

Li, Chang-dong; Zhang, Wei-yuan; Yuan, Chun-li; Han, Li-ying

2008-12-09

To develop a new method to promote the differentiation of mesenchymal stem cells derived from human placenta (pMSC) to uterus smooth muscle cells (uSMC) in simulated uterus microenvironment. MSCs were isolated from human placenta, cultivated, and analyzed for their phenotype by flow cytometry. The multipotential differentiation of the pMSC was examined by chondrogenic, adipogenic, and osteogenetic induction. uSMC were isolated from uteri resected during operation and co-cultivated with the pMSC in a Transwell chamber simulating Two, 4, and 8 days later RT-PCR and Western blotting were used to detect the mRNA and protein expression of alpha-actin, calmodulin, and myosin heavy chains (MHC), the markers of smooth muscle differentiation at the early, middle, and late stages. On day 8 RT-PCR was used to detect the expression of estrogen receptor in these 2 groups of cells, then estrogen was used to stimulate these cells and the protein kinase C (PKC) activity was examined. The pMSC could be induced into adipocytes, osteocytes, and chondrocytes respectively. After co-culture with uSMC, the morphology of the pMSC changed closely into that of the uSMC, and MHC was expressed in the pMSC. Estrogen receptor was positive in both groups of cells. The PKC activity increased, especially in the cell membrane, after stimulation of estrogen. The postpartum human placenta can be used as an important and novel source of multipotent stem cells for tissue engineering and genetic engineering. Placental MSC have the potential to differentiate into smooth muscle cells under the simulated uterus microenvironment in vitro.

Treatment with selective estrogen receptor modulators regulates myelin specific T-cells and suppresses experimental autoimmune encephalomyelitis.

PubMed

Bebo, Bruce F; Dehghani, Babak; Foster, Scott; Kurniawan, Astrid; Lopez, Francisco J; Sherman, Larry S

2009-05-01

Steroidal estrogens can regulate inflammatory immune responses and may be involved in the suppression of multiple sclerosis (MS) during pregnancy. However, the risks and side effects associated with steroidal estrogens may limit their usefulness for long-term MS therapy. Selective estrogen receptor modulators (SERMs) could provide an alternative therapeutic strategy, because they behave as estrogen agonists in some tissues, but are either inert or behave like estrogen antagonists in other tissues. In this study, we investigated the ability of two commercially available SERMs (tamoxifen and raloxifene) to regulate myelin specific immunity and experimental autoimmune encephalomyelitis (EAE) in mice. Both tamoxifen and raloxifene suppressed myelin antigen specific T-cell proliferation. However, tamoxifen was more effective in this regard. Tamoxifen treatment reduced the induction of major histocompatibility complex II by lipopolysaccharide stimulated dendritic cells and decreased their ability to activate myelin specific T-cells. At lower doses, tamoxifen was found to increase the levels of Th2 transcription factors and induce a Th2 bias in cultures of myelin-specific splenocytes. EAE symptoms and the degree of demyelination were less severe in mice treated with tamoxifen than in control mice. These findings support the notion that tamoxifen or related SERMs are potential agents that could be used in the treatment of inflammatory autoimmune disorders that affect the central nervous system.

GPER negatively regulates TNFα-induced IL-6 production in human breast cancer cells via NF-κB pathway.

PubMed

Okamoto, Mariko; Mizukami, Yoichi

2016-05-31

Estrogen is known to have anti-inflammatory effects, that are thought to be mediated by the classical estrogen receptors (ERs), ERα and ERβ. G protein coupled estrogen receptor1 (GPER) is a novel membrane-type estrogen receptor that can mediate non-genomic estrogenic responses. Although there have been several reports asserting that the participation of GPER in anti-inflammatory effects is induced by estrogen, the role of GPER remains poorly understood. In this study, we investigated the involvement of GPER in the regulation of a representative inflammatory cytokine, IL-6. We first examined the expression of IL-6 mRNA by TNFα stimulation in the transfection of GPER-expression plasmid into HeLa cells. Exogenous GPER significantly inhibited TNFα-induced IL-6 expression, and blocked NF-κB promoter activity inducing the expression of IL-6 in a dose-dependent manner. The promoter activity was restored almost to control level by transfection with the C-terminal deletion mutant of GPER. Similar results have been observed in endogenous GPER using SKBR3 cells which do not express the classical ERs. The data have been validated by treatment of GPER with siRNA. These findings indicate that GPER negatively regulates TNFα-induced IL-6 expression, probably through inhibition of NF-κB promoter activity by a signal(s) derived from the C-terminal region of GPER.

Extracellular matrix integrity: a possible mechanism for differential clinical effects among selective estrogen receptor modulators and estrogens?

PubMed

Cox, David A; Helvering, Leah M

2006-03-09

Recent gene microarray studies have illustrated heterogeneity in gene expression changes not only between estrogens and selective estrogen receptor modulators (SERMs), but also across different SERM molecules. In ovariectomized rats, this phenomenon was observed with respect to a number of genes involved in collagen turnover and extracellular matrix (ECM) integrity in the uterus and vaginal tissues. Preliminary mechanistic data suggest that these effects on ECM integrity may have relevance in the context of the effect of estrogens and some SERMs to increase the risk of pelvic organ prolapse and the incidence of urinary incontinence in postmenopausal women. Given the pivotal role of ECM integrity and collagen turnover in other tissues and disease states, these processes may provide a fruitful target for future research into the mechanisms for the heterogeneous pharmacology of estrogens and SERMs across different cell types and target tissues.

Cellular and molecular effects of developmental exposure to diethylstilbestrol: implications for other environmental estrogens.

PubMed Central

Newbold, R

1995-01-01

Concerns have been raised regarding the role of environmental and dietary estrogens as possible contributors to an increased incidence of various abnormalities in estrogen-target tissues of both sexes. These abnormalities include breast cancer, endometriosis, fibroids, and uterine adenocarcinoma in females, as well as alterations in sex differentiation, decreased sperm concentrations, benign prostatic hyperplasia, prostatic cancer, testicular cancer, and reproductive problems in males. Whether these concerns are valid remains to be determined; however, studies with the potent synthetic estrogen diethylstilbestrol (DES) suggest that exogenous estrogen exposure during critical stages of development can result in permanent cellular and molecular alterations in the exposed organism. These alterations manifest themselves in the female and male as structural, functional, or long-term pathological changes including neoplasia. Although DES has potent estrogenic activity, it may be used as a model compound to study the effects of weaker environmental estrogens, many of which may fit into the category of endocrine disruptors. PMID:8593881

Virtual and biomolecular screening converge on a selective agonist for GPR30.

PubMed

Bologa, Cristian G; Revankar, Chetana M; Young, Susan M; Edwards, Bruce S; Arterburn, Jeffrey B; Kiselyov, Alexander S; Parker, Matthew A; Tkachenko, Sergey E; Savchuck, Nikolay P; Sklar, Larry A; Oprea, Tudor I; Prossnitz, Eric R

2006-04-01

Estrogen is a hormone critical in the development, normal physiology and pathophysiology of numerous human tissues. The effects of estrogen have traditionally been solely ascribed to estrogen receptor alpha (ERalpha) and more recently ERbeta, members of the soluble, nuclear ligand-activated family of transcription factors. We have recently shown that the seven-transmembrane G protein-coupled receptor GPR30 binds estrogen with high affinity and resides in the endoplasmic reticulum, where it activates multiple intracellular signaling pathways. To differentiate between the functions of ERalpha or ERbeta and GPR30, we used a combination of virtual and biomolecular screening to isolate compounds that selectively bind to GPR30. Here we describe the identification of the first GPR30-specific agonist, G-1 (1), capable of activating GPR30 in a complex environment of classical and new estrogen receptors. The development of compounds specific to estrogen receptor family members provides the opportunity to increase our understanding of these receptors and their contribution to estrogen biology.

Estrogens in Male Physiology.

PubMed

Cooke, Paul S; Nanjappa, Manjunatha K; Ko, CheMyong; Prins, Gail S; Hess, Rex A

2017-07-01

Estrogens have historically been associated with female reproduction, but work over the last two decades established that estrogens and their main nuclear receptors (ESR1 and ESR2) and G protein-coupled estrogen receptor (GPER) also regulate male reproductive and nonreproductive organs. 17β-Estradiol (E2) is measureable in blood of men and males of other species, but in rete testis fluids, E2 reaches concentrations normally found only in females and in some species nanomolar concentrations of estrone sulfate are found in semen. Aromatase, which converts androgens to estrogens, is expressed in Leydig cells, seminiferous epithelium, and other male organs. Early studies showed E2 binding in numerous male tissues, and ESR1 and ESR2 each show unique distributions and actions in males. Exogenous estrogen treatment produced male reproductive pathologies in laboratory animals and men, especially during development, and studies with transgenic mice with compromised estrogen signaling demonstrated an E2 role in normal male physiology. Efferent ductules and epididymal functions are dependent on estrogen signaling through ESR1, whose loss impaired ion transport and water reabsorption, resulting in abnormal sperm. Loss of ESR1 or aromatase also produces effects on nonreproductive targets such as brain, adipose, skeletal muscle, bone, cardiovascular, and immune tissues. Expression of GPER is extensive in male tracts, suggesting a possible role for E2 signaling through this receptor in male reproduction. Recent evidence also indicates that membrane ESR1 has critical roles in male reproduction. Thus estrogens are important physiological regulators in males, and future studies may reveal additional roles for estrogen signaling in various target tissues. Copyright © 2017 the American Physiological Society.

Genome-wide activity of unliganded estrogen receptor-α in breast cancer cells

PubMed Central

Caizzi, Livia; Ferrero, Giulio; Cutrupi, Santina; Cordero, Francesca; Ballaré, Cecilia; Miano, Valentina; Reineri, Stefania; Ricci, Laura; Friard, Olivier; Testori, Alessandro; Corà, Davide; Caselle, Michele; Di Croce, Luciano; De Bortoli, Michele

2014-01-01

Estrogen receptor-α (ERα) has central role in hormone-dependent breast cancer and its ligand-induced functions have been extensively characterized. However, evidence exists that ERα has functions that are independent of ligands. In the present work, we investigated the binding of ERα to chromatin in the absence of ligands and its functions on gene regulation. We demonstrated that in MCF7 breast cancer cells unliganded ERα binds to more than 4,000 chromatin sites. Unexpectedly, although almost entirely comprised in the larger group of estrogen-induced binding sites, we found that unliganded-ERα binding is specifically linked to genes with developmental functions, compared with estrogen-induced binding. Moreover, we found that siRNA-mediated down-regulation of ERα in absence of estrogen is accompanied by changes in the expression levels of hundreds of coding and noncoding RNAs. Down-regulated mRNAs showed enrichment in genes related to epithelial cell growth and development. Stable ERα down-regulation using shRNA, which caused cell growth arrest, was accompanied by increased H3K27me3 at ERα binding sites. Finally, we found that FOXA1 and AP2γ binding to several sites is decreased upon ERα silencing, suggesting that unliganded ERα participates, together with other factors, in the maintenance of the luminal-specific cistrome in breast cancer cells. PMID:24639548

Letrozole induced low estrogen levels affected the expressions of duodenal and renal calcium-processing gene in laying hens.

PubMed

Li, Qiao; Zhao, Xingkai; Wang, Shujie; Zhou, Zhenlei

2018-01-01

Estrogen regulates the calcium homeostasis in hens, but the mechanisms involved are still unclear fully. In this study, we investigated whether letrozole (LZ) induced low estrogen levels affected the calcium absorption and transport in layers. In the duodenum, we observed a significant decrease of mRNA expressions of Calbindin-28k (CaBP-28k) and plasma membrane Ca 2+ -ATPase (PMCA 1b) while CaBP-28k protein expression was declined in birds with LZ treatment, and the mRNA levels of duodenal transient receptor potential vanilloid 6 (TRPV6) and Na + /Ca 2+ exchanger 1 (NCX1) were not affected. Interestingly, we observed the different changes in the kidney. The renal mRNA expressions of TRPV6 and NCX1 were unregulated while the PMCA1b was down-regulated in low estrogen layers, however, the CaBP-28k gene and protein expressions were no changed in the kidney. Furthermore, it showed that the duodenal estradiol receptor 2 (ESR2) transcripts rather than parathyroid hormone 1 receptor (PTH1R) and calcitonin receptor (CALCR) played key roles to down-regulate calcium transport in LZ-treated birds. In conclusion, CaBP-28k, PMCA 1b and ESR2 genes in the duodenum may be primary targets for estrogen regulation in order to control calcium homeostasis in hens. Copyright © 2017 Elsevier Inc. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Hee-Jung; Division of Applied Medicine, School of Korean Medicine, Pusan National University, Yangsan-city, Gyeongsangnam-do; Chung, Tae-Wook

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 expressedmore » 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 these results, we propose that estrogen regulates the expression of B4GALT1 through the direct binding of ER-{alpha} to ERE and that the expressed B4GALT1 plays a crucial role in the proliferation of MCF-7 cells through its activity as a membrane receptor.« less

Estrogen receptor α is required for oviductal transport of embryos

PubMed Central

Li, Shuai; O’Neill, Sofia R. S.; Zhang, Yong; Holtzman, Michael J.; Takemaru, Ken-Ichi; Korach, Kenneth S.; Winuthayanon, Wipawee

2017-01-01

Newly fertilized embryos spend the first few days within the oviduct and are transported to the uterus, where they implant onto the uterine wall. An implantation of the embryo before reaching the uterus could result in ectopic pregnancy and lead to maternal death. Estrogen is necessary for embryo transport in mammals; however, the mechanism involved in estrogen-mediated cellular function within the oviduct remains unclear. In this study, we show in mouse models that ciliary length and beat frequency of the oviductal epithelial cells are regulated through estrogen receptor α (ESR1) but not estrogen receptor β (ESR2). Gene profiling indicated that transcripts in the WNT/β-catenin (WNT/CTNNB1) signaling pathway were regulated by estrogen in mouse oviduct, and inhibition of this pathway in a whole oviduct culture system resulted in a decreased embryo transport distance. However, selective ablation of CTNNB1 from the oviductal ciliated cells did not affect embryo transport, possibly because of a compensatory mechanism via intact CTNNB1 in the adjacent secretory cells. In summary, we demonstrated that disruption of estrogen signaling in oviductal epithelial cells alters ciliary function and impairs embryo transport. Therefore, our findings may provide a better understanding of etiology of the ectopic pregnancy that is associated with alteration of estrogen signals.—Li, S., O’Neill, S. R. S., Zhang, Y., Holtzman, M. J., Takemaru, K.-I., Korach, K. S., Winuthayanon, W. Estrogen receptor α is required for oviductal transport of embryos. PMID:28082352

GPER Mediates Non-Genomic Effects of Estrogen.

PubMed

Pupo, Marco; Maggiolini, Marcello; Musti, Anna Maria

2016-01-01

Estrogens are important modulators of a broad spectrum of physiological functions in humans. However, despite their beneficial actions, a number of lines of evidence correlate the sustained exposure to exogenous estrogen with increased risk of the onset of various cancers. Mainly these steroid hormones induce their effects by binding and activating estrogen receptors (ERα and ERβ). These receptors belong to the family of ligand-regulated transcription factors, and upon activation they regulate the expression of different target genes by binding directly to specific DNA sequences. On the other hand, in recent years it has become clear that the G protein-coupled estrogen receptor 30 (GPR30/GPER) is able to mediate non-genomic action of estrogens in different cell contexts. In particular, GPER has been shown to specifically bind estrogens, and in turn to functionally cross-react with diverse cell signaling systems such as the epidermal growth factor receptor (EGFR) pathway, the Notch signaling pathway and the mitogen-activated protein kinases (MAPK) pathway. In this chapter we will present some of the different experimental techniques currently used to demonstrate the functional role of GPER in mediating non-genomic actions of estrogens, such as the dual luciferase assay, assessment of the involvement of GPER in the stimulation of cell migration in breast cancer cell lines and in cancer-associated fibroblasts, and chromatin immunoprecipitation assay. Overall, the experimental procedures described herein represent key instruments for assessing the biological role of GPER in mediating non-genomic signals of estrogen.

Sex steroids regulate skin pigmentation through nonclassical membrane-bound receptors

PubMed Central

Natale, Christopher A; Duperret, Elizabeth K; Zhang, Junqian; Sadeghi, Rochelle; Dahal, Ankit; O'Brien, Kevin Tyler; Cookson, Rosa; Winkler, Jeffrey D; Ridky, Todd W

2016-01-01

The association between pregnancy and altered cutaneous pigmentation has been documented for over two millennia, suggesting that sex hormones play a role in regulating epidermal melanocyte (MC) homeostasis. Here we show that physiologic estrogen (17β-estradiol) and progesterone reciprocally regulate melanin synthesis. This is intriguing given that we also show that normal primary human MCs lack classical estrogen or progesterone receptors (ER or PR). Utilizing both genetic and pharmacologic approaches, we establish that sex steroid effects on human pigment synthesis are mediated by the membrane-bound, steroid hormone receptors G protein-coupled estrogen receptor (GPER), and progestin and adipoQ receptor 7 (PAQR7). Activity of these receptors was activated or inhibited by synthetic estrogen or progesterone analogs that do not bind to ER or PR. As safe and effective treatment options for skin pigmentation disorders are limited, these specific GPER and PAQR7 ligands may represent a novel class of therapeutics. DOI: http://dx.doi.org/10.7554/eLife.15104.001 PMID:27115344

Microarray analysis on gene regulation by estrogen, progesterone and tamoxifen in human endometrial stromal cells.

PubMed

Ren, Chun-E; Zhu, Xueqiong; Li, Jinping; Lyle, Christian; Dowdy, Sean; Podratz, Karl C; Byck, David; Chen, Hai-Bin; Jiang, Shi-Wen

2015-03-13

Epithelial stromal cells represent a major cellular component of human uterine endometrium that is subject to tight hormonal regulation. Through cell-cell contacts and/or paracrine mechanisms, stromal cells play a significant role in the malignant transformation of epithelial cells. We isolated stromal cells from normal human endometrium and investigated the morphological and transcriptional changes induced by estrogen, progesterone and tamoxifen. We demonstrated that stromal cells express appreciable levels of estrogen and progesterone receptors and undergo different morphological changes upon hormonal stimulation. Microarray analysis indicated that both estrogen and progesterone induced dramatic alterations in a variety of genes associated with cell structure, transcription, cell cycle, and signaling. However, divergent patterns of changes, and in some genes opposite effects, were observed for the two hormones. A large number of genes are identified as novel targets for hormonal regulation. These hormone-responsive genes may be involved in normal uterine function and the development of endometrial malignancies.

Female Mice Lacking Estrogen Receptor-α in Hypothalamic Proopiomelanocortin (POMC) Neurons Display Enhanced Estrogenic Response on Cortical Bone Mass.

PubMed

Farman, H H; Windahl, S H; Westberg, L; Isaksson, H; Egecioglu, E; Schele, E; Ryberg, H; Jansson, J O; Tuukkanen, J; Koskela, A; Xie, S K; Hahner, L; Zehr, J; Clegg, D J; Lagerquist, M K; Ohlsson, C

2016-08-01

Estrogens are important regulators of bone mass and their effects are mainly mediated via estrogen receptor (ER)α. Central ERα exerts an inhibitory role on bone mass. ERα is highly expressed in the arcuate (ARC) and the ventromedial (VMN) nuclei in the hypothalamus. To test whether ERα in proopiomelanocortin (POMC) neurons, located in ARC, is involved in the regulation of bone mass, we used mice lacking ERα expression specifically in POMC neurons (POMC-ERα(-/-)). Female POMC-ERα(-/-) and control mice were ovariectomized (OVX) and treated with vehicle or estradiol (0.5 μg/d) for 6 weeks. As expected, estradiol treatment increased the cortical bone thickness in femur, the cortical bone mechanical strength in tibia and the trabecular bone volume fraction in both femur and vertebrae in OVX control mice. Importantly, the estrogenic responses were substantially increased in OVX POMC-ERα(-/-) mice compared with the estrogenic responses in OVX control mice for cortical bone thickness (+126 ± 34%, P < .01) and mechanical strength (+193 ± 38%, P < .01). To test whether ERα in VMN is involved in the regulation of bone mass, ERα was silenced using an adeno-associated viral vector. Silencing of ERα in hypothalamic VMN resulted in unchanged bone mass. In conclusion, mice lacking ERα in POMC neurons display enhanced estrogenic response on cortical bone mass and mechanical strength. We propose that the balance between inhibitory effects of central ERα activity in hypothalamic POMC neurons in ARC and stimulatory peripheral ERα-mediated effects in bone determines cortical bone mass in female mice.

Insights into Rapid Modulation of Neuroplasticity by Brain Estrogens

PubMed Central

Woolfrey, Kevin M.; Penzes, Peter

2013-01-01

Converging evidence from cellular, electrophysiological, anatomic, and behavioral studies suggests that the remodeling of synapse structure and function is a critical component of cognition. This modulation of neuroplasticity can be achieved through the actions of numerous extracellular signals. Moreover, it is thought that it is the integration of different extracellular signals regulation of neuroplasticity that greatly influences cognitive function. One group of signals that exerts powerful effects on multiple neurologic processes is estrogens. Classically, estrogens have been described to exert their effects over a period of hours to days. However, there is now increasing evidence that estrogens can rapidly influence multiple behaviors, including those that require forebrain neural circuitry. Moreover, these effects are found in both sexes. Critically, it is now emerging that the modulation of cognition by rapid estrogenic signaling is achieved by activation of specific signaling cascades and regulation of synapse structure and function, cumulating in the rewiring of neural circuits. The importance of understanding the rapid effects of estrogens on forebrain function and circuitry is further emphasized as investigations continue to consider the potential of estrogenic-based therapies for neuropathologies. This review focuses on how estrogens can rapidly influence cognition and the emerging mechanisms that underlie these effects. We discuss the potential sources and the biosynthesis of estrogens within the brain and the consequences of rapid estrogenic-signaling on the remodeling of neural circuits. Furthermore, we argue that estrogens act via distinct signaling pathways to modulate synapse structure and function in a manner that may vary with cell type, developmental stage, and sex. Finally, we present a model in which the coordination of rapid estrogenic-signaling and activity-dependent stimuli can result in long-lasting changes in neural circuits, contributing to cognition, with potential relevance for the development of novel estrogenic-based therapies for neurodevelopmental or neurodegenerative disorders. PMID:24076546

Estrogen biology: new insights into GPER function and clinical opportunities.

PubMed

Prossnitz, Eric R; Barton, Matthias

2014-05-25

Estrogens play an important role in the regulation of normal physiology, aging and many disease states. Although the nuclear estrogen receptors have classically been described to function as ligand-activated transcription factors mediating genomic effects in hormonally regulated tissues, more recent studies reveal that estrogens also mediate rapid signaling events traditionally associated with G protein-coupled receptors. The G protein-coupled estrogen receptor GPER (formerly GPR30) has now become recognized as a major mediator of estrogen's rapid cellular effects throughout the body. With the discovery of selective synthetic ligands for GPER, both agonists and antagonists, as well as the use of GPER knockout mice, significant advances have been made in our understanding of GPER function at the cellular, tissue and organismal levels. In many instances, the protective/beneficial effects of estrogen are mimicked by selective GPER agonism and are absent or reduced in GPER knockout mice, suggesting an essential or at least parallel role for GPER in the actions of estrogen. In this review, we will discuss recent advances and our current understanding of the role of GPER and the activity of clinically used drugs, such as SERMs and SERDs, in physiology and disease. We will also highlight novel opportunities for clinical development towards GPER-targeted therapeutics, for molecular imaging, as well as for theranostic approaches and personalized medicine. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Female Mice Avoid Male Odor from the Same Strain via the Vomeronasal System in an Estrogen-Dependent Manner.

PubMed

Yano, Saori; Sakamoto, Kentaro Q; Habara, Yoshiaki

2015-11-01

Inbreeding avoidance is essential to providing offspring with genetic diversity. Females' mate choice is more crucial than males' for successful reproduction because of the high cost of producing gametes and limited chances to mate. However, the mechanism of female inbreeding avoidance is still unclear. To elucidate the mechanism underlying inbreeding avoidance by females, we conducted Y-maze behavioral assays using BALB/c and C57BL/6 female mice. In both strains, the avoidance of male urine from the same strain was lower in the low estrogen phase than in the high estrogen phase. The estrous cycle-dependent avoidance was completely prevented by vomeronasal organ (VNO) removal. To assess the regulation of the vomeronasal system by estrogen, the neural excitability was evaluated by immunohistochemistry of the immediate early gene products. Although estrogen did not affect neural excitability in the VNO, estrogen enhanced the neural excitability of the mitral cell layer in the AOB induced by urine from the cognate males. These results suggest that female mice avoid odor from genetically similar males in an estrogen-dependent manner via the vomeronasal system and the excitability of the mitral cells in the AOB is presumed to be regulated by estrogen. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Stromal-epithelial interaction mediates steroidal regulation of metalloproteinase expression in human endometrium.

PubMed Central

Osteen, K G; Rodgers, W H; Gaire, M; Hargrove, J T; Gorstein, F; Matrisian, L M

1994-01-01

The hallmark of the menstrual cycle is extensive steroid-dependent tissue turnover. Estrogen mediates endometrial cell growth and structural remodeling, whereas progesterone suppresses estrogen-dependent proliferation and promotes cellular differentiation. In nonfertile cycles, tissue degradation and menstruation occur as a consequence of steroidal deprivation as the ovarian corpus luteum fails. Stromal-epithelial interactions are recognized as a necessary component in mediating steroid-induced endometrial turnover. Specific mRNAs for metalloproteinases of the stromelysin family are expressed during endometrial growth and menstrual breakdown but are absent in the progestin-dominated secretory phase. This expression pattern suggests involvement of stromelysins in remodeling the extracellular matrix of the endometrium during tissue growth and breakdown and implicates progesterone in the suppression of these enzymes. We examined the regulation of endometrial stromelysins in explant cultures and found no acute effect of estradiol on their expression, whereas progesterone was a potent inhibitor of stromelysin expression. Progesterone also suppressed stromelysin expression in cultures of isolated stromal cells, but epithelial cells were progesterone insensitive. Coculture of recombined stromal and epithelial cells restored steroidal suppression of the epithelial-specific metalloproteinase. Our data confirm that progesterone inhibits endometrial stromelysins and further demonstrate the necessity for a stromal-derived factor(s) as a mediator of steroid suppression of an epithelial metalloproteinase. Images PMID:7937850

Aromatase expression is linked to estrogenic sensitivity of periurethral muscles in female rabbits.

PubMed

de los Ángeles Carrasco-Ruiz, María; García-Villamar, Verónica; López-García, Kenia; Sánchez-García, Octavio; Pacheco, Pablo; Cuevas, Estela; Martínez-Gómez, Margarita; Castelán, Francisco

2015-06-01

Beyond its role in the conversion of androgens to estrogens, the expression of aromatase could influence on the estrogenic signalling in targeted tissues. Considering the well-defined biochemical and physiological differences between the pubococcygeus (Pcm) and bulbospongiosus (Bsm) muscles in female rabbits, it is presently hypothesized that the aromatase expression is differentially linked to the estrogen sensitivity of each muscle. To this end, serum estradiol levels and the aromatase expression, presence of ERα and ERβ and morphometry were evaluated in the Pcm and Bsm of female rabbits allocated in control, ovariectomized (OVX) and OVX treated with estradiol benzoate (OVX + EB) groups. Aromatase expression was high in the Pcm. Independently to serum estradiol, ovariectomy increased aromatase expression in the Pcm while decreased it in the Bsm. The EB treatment avoided the effect of ovariectomy only in the Pcm. The number of immunoreactive nuclei anti-ERα and anti-ERβ was high in the Pcm of OVX and OVX + EB rabbits, while those in the Bsm remained unchanged. The number of peripheral nuclei per fibre and the cross-sectional area-to-myonucleus ratio were modified only in the Pcm. Our findings support aromatase expression in the Pcm, and Bsm of rabbits is differentially linked to estrogenic sensitivity of each muscle. Copyright © 2015 John Wiley & Sons, Ltd.

3D-QSAR Study of Steroidal and Azaheterocyclic Human Aromatase Inhibitors using Quantitative Profile of Protein-Ligand Interactions

EPA Science Inventory

Aromatase is a member of the cytochrome P450 superfamily responsible for a key step in the biosynthesis of estrogens. As estrogens are involved in the control of important reproduction-related processes, including sexual differentiation and maturation, aromatase is a potential ta...

Differential response of two somatolactin genes to zinc or estrogen in pituitary of Cyprinus carpio.

PubMed

Valenzuela, G E; Perez, A; Navarro, M; Romero, A; Figueroa, J; Kausel, G

2015-05-01

Environmental changes affect gene expression that we addressed in the pituitary, a central regulatory organ at the interface between the central nervous system and the endocrine system. With the aim to reveal effects of changes in the aquatic environment on the expression of hypothalamo-hypophyseal factors, we characterized somatolactin (SL) in Cyprinus carpio. SL, a fish specific pituitary hormone belonging to the prolactin (PRL) superfamily, is involved in background adaptation, osmoregulation, reproduction and fatty acid metabolism. Two sl genes, α and β, were discovered in carp and transcripts of both were detected in pituitaries. Clearly, expression of slα and slβ was modulated significantly in pituitary of male adult carp in response to treatment with ZnCl2 (Zn), but only slβ responded to 17β-estrogen (E2), relative to control carp as shown by RT-qPCR analyses. Furthermore, the amount of mRNA of related factors was assessed revealing variable effects on prl, growth hormone (gh), and factors involved in sl regulation: the pituitary transcription factor pit1 and hypothalamic pituitary adenylase cyclase activating peptide (pacap). In parallel, the physiological response of the experimental animals to Zn or E2 was confirmed by showing a significant increase of metallothionein (mt) or vitellogenin (vg) gene expression in liver, classical sentinels for exposure to heavy metal or estrogens. These data suggest that the sl genes seem to be involved in the response to Zn, as well as to estrogen, and could contribute to evaluate biological relevant changes in the aquatic environment. Copyright © 2014 Elsevier Inc. All rights reserved.

Antiestrogenic activity of flavnoid phytochemicals mediated via c-Jun N-terminal protein kinase pathway. Cell-type specific regulation of estrogen receptor alpha

USDA-ARS?s Scientific Manuscript database

Flavonoid phytochemicals act as both agonists and antagonists of the human estrogen receptors (ERs). While a number of these compounds act by directly binding to the ER, certain phytochemicals, such as the flavonoid compounds chalcone and flavone, elicit antagonistic effects on estrogen signaling in...

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…

17β-Estradiol and Agonism of G-protein-Coupled Estrogen Receptor Enhance Hippocampal Memory via Different Cell-Signaling Mechanisms

PubMed Central

Kim, Jaekyoon; Szinte, Julia S.; Boulware, Marissa I.

2016-01-01

The ability of 17β-estradiol (E2) to enhance hippocampal object recognition and spatial memory depends on rapid activation of extracellular signal-regulated kinase (ERK) in the dorsal hippocampus (DH). Although this activation can be mediated by the intracellular estrogen receptors ERα and ERβ, little is known about the role that the membrane estrogen receptor GPER plays in regulating ERK or E2-mediated memory formation. In this study, post-training DH infusion of the GPER agonist G-1 enhanced object recognition and spatial memory in ovariectomized female mice, whereas the GPER antagonist G-15 impaired memory, suggesting that GPER activation, like E2, promotes hippocampal memory formation. However, unlike E2, G-1 did not increase ERK phosphorylation, but instead significantly increased phosphorylation of c-Jun N-terminal kinase (JNK) in the DH. Moreover, DH infusion of the JNK inhibitor SP600125 prevented G-1 from enhancing object recognition and spatial memory, but the ERK inhibitor U0126 did not. These data suggest that GPER enhances memory via different cell-signaling mechanisms than E2. This conclusion was supported by data showing that the ability of E2 to facilitate memory and activate ERK signaling was not blocked by G-15 or SP600125, which demonstrates that the memory-enhancing effects of E2 are not dependent on JNK or GPER activation in the DH. Together, these data indicate that GPER regulates memory independently from ERα and ERβ by activating JNK signaling, rather than ERK signaling. Thus, the findings suggest that GPER in the DH may not function as an estrogen receptor to regulate object recognition and spatial memory. SIGNIFICANCE STATEMENT Although 17β-estradiol has long been known to regulate memory function, the molecular mechanisms underlying estrogenic memory modulation remain largely unknown. Here, we examined whether the putative membrane estrogen receptor GPER acts like the classical estrogen receptors, ERα and ERβ, to facilitate hippocampal memory in female mice. Although GPER activation did enhance object recognition and spatial memory, it did so by activating different cell-signaling mechanisms from ERα, ERβ, or 17β-estradiol. These data indicate that 17β-estradiol and GPER independently regulate hippocampal memory, and suggest that hippocampal GPER may not function as an estrogen receptor in the dorsal hippocampus. These findings are significant because they provide novel insights about the molecular mechanisms through which 17β-estradiol modulates hippocampal memory. PMID:26985039

17β-Estradiol and Agonism of G-protein-Coupled Estrogen Receptor Enhance Hippocampal Memory via Different Cell-Signaling Mechanisms.

PubMed

Kim, Jaekyoon; Szinte, Julia S; Boulware, Marissa I; Frick, Karyn M

2016-03-16

The ability of 17β-estradiol (E2) to enhance hippocampal object recognition and spatial memory depends on rapid activation of extracellular signal-regulated kinase (ERK) in the dorsal hippocampus (DH). Although this activation can be mediated by the intracellular estrogen receptors ERα and ERβ, little is known about the role that the membrane estrogen receptor GPER plays in regulating ERK or E2-mediated memory formation. In this study, post-training DH infusion of the GPER agonist G-1 enhanced object recognition and spatial memory in ovariectomized female mice, whereas the GPER antagonist G-15 impaired memory, suggesting that GPER activation, like E2, promotes hippocampal memory formation. However, unlike E2, G-1 did not increase ERK phosphorylation, but instead significantly increased phosphorylation of c-Jun N-terminal kinase (JNK) in the DH. Moreover, DH infusion of the JNK inhibitor SP600125 prevented G-1 from enhancing object recognition and spatial memory, but the ERK inhibitor U0126 did not. These data suggest that GPER enhances memory via different cell-signaling mechanisms than E2. This conclusion was supported by data showing that the ability of E2 to facilitate memory and activate ERK signaling was not blocked by G-15 or SP600125, which demonstrates that the memory-enhancing effects of E2 are not dependent on JNK or GPER activation in the DH. Together, these data indicate that GPER regulates memory independently from ERα and ERβ by activating JNK signaling, rather than ERK signaling. Thus, the findings suggest that GPER in the DH may not function as an estrogen receptor to regulate object recognition and spatial memory. Although 17β-estradiol has long been known to regulate memory function, the molecular mechanisms underlying estrogenic memory modulation remain largely unknown. Here, we examined whether the putative membrane estrogen receptor GPER acts like the classical estrogen receptors, ERα and ERβ, to facilitate hippocampal memory in female mice. Although GPER activation did enhance object recognition and spatial memory, it did so by activating different cell-signaling mechanisms from ERα, ERβ, or 17β-estradiol. These data indicate that 17β-estradiol and GPER independently regulate hippocampal memory, and suggest that hippocampal GPER may not function as an estrogen receptor in the dorsal hippocampus. These findings are significant because they provide novel insights about the molecular mechanisms through which 17β-estradiol modulates hippocampal memory. Copyright © 2016 the authors 0270-6474/16/363309-13$15.00/0.

Estrogen receptor α dependent regulation of estrogen related receptor β and its role in cell cycle in breast cancer.

PubMed

Madhu Krishna, B; Chaudhary, Sanjib; Mishra, Dipti Ranjan; Naik, Sanoj K; Suklabaidya, S; Adhya, A K; Mishra, Sandip K

2018-05-30

Breast cancer (BC) is highly heterogeneous with ~ 60-70% of estrogen receptor positive BC patient's response to anti-hormone therapy. Estrogen receptors (ERs) play an important role in breast cancer progression and treatment. Estrogen related receptors (ERRs) are a group of nuclear receptors which belong to orphan nuclear receptors, which have sequence homology with ERs and share target genes. Here, we investigated the possible role and clinicopathological importance of ERRβ in breast cancer. Estrogen related receptor β (ERRβ) expression was examined using tissue microarray slides (TMA) of Breast Carcinoma patients with adjacent normal by immunohistochemistry and in breast cancer cell lines. In order to investigate whether ERRβ is a direct target of ERα, we investigated the expression of ERRβ in short hairpin ribonucleic acid knockdown of ERα breast cancer cells by western blot, qRT-PCR and RT-PCR. We further confirmed the binding of ERα by electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP), Re-ChIP and luciferase assays. Fluorescence-activated cell sorting analysis (FACS) was performed to elucidate the role of ERRβ in cell cycle regulation. A Kaplan-Meier Survival analysis of GEO dataset was performed to correlate the expression of ERRβ with survival in breast cancer patients. Tissue microarray (TMA) analysis showed that ERRβ is significantly down-regulated in breast carcinoma tissue samples compared to adjacent normal. ER + ve breast tumors and cell lines showed a significant expression of ERRβ compared to ER-ve tumors and cell lines. Estrogen treatment significantly induced the expression of ERRβ and it was ERα dependent. Mechanistic analyses indicate that ERα directly targets ERRβ through estrogen response element and ERRβ also mediates cell cycle regulation through p18, p21 cip and cyclin D1 in breast cancer cells. Our results also showed the up-regulation of ERRβ promoter activity in ectopically co-expressed ERα and ERRβ breast cancer cell lines. Fluorescence-activated cell sorting analysis (FACS) showed increased G0/G1 phase cell population in ERRβ overexpressed MCF7 cells. Furthermore, ERRβ expression was inversely correlated with overall survival in breast cancer. Collectively our results suggest cell cycle and tumor suppressor role of ERRβ in breast cancer cells which provide a potential avenue to target ERRβ signaling pathway in breast cancer. Our results indicate that ERRβ is a negative regulator of cell cycle and a possible tumor suppressor in breast cancer. ERRβ could be therapeutic target for the treatment of breast cancer.

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

PubMed Central

Davis, Kathryn E.; D. Neinast, Michael; Sun, Kai; M. Skiles, William; D. Bills, Jessica; A. Zehr, Jordan; Zeve, Daniel; D. Hahner, Lisa; W. Cox, Derek; M. Gent, Lana; Xu, Yong; V. Wang, Zhao; A. Khan, Sohaib; Clegg, Deborah J.

2013-01-01

Our data demonstrate that estrogens, estrogen receptor-α (ERα), and estrogen receptor-β (ERβ) regulate adipose tissue distribution, inflammation, fibrosis, and glucose homeostasis, by determining that αERKO mice have increased adipose tissue inflammation and fibrosis prior to obesity onset. Selective deletion of adipose tissue ERα in adult mice using a novel viral vector technology recapitulated the findings in the total body ERα null mice. Generation of a novel mouse model, lacking ERα specifically from adipocytes (AdipoERα), demonstrated increased markers of fibrosis and inflammation, especially in the males. Additionally, we found that the beneficial effects of estrogens on adipose tissue require adipocyte ERα. Lastly, we determined the role of ERβ in regulating inflammation and fibrosis, by breeding the AdipoERα into the βERKO background and found that in the absence of adipocyte ERα, ERβ has a protective role. These data suggest that adipose tissue and adipocyte ERα protects against adiposity, inflammation, and fibrosis in both males and females. PMID:24049737

Estrogen Enhances Malignant Phenotypes in Human Salivary Adenoid Cystic Carcinoma Cells.

PubMed

Sumida, Tomoki; Ishikawa, Akiko; Kamata, Y U; Nakano, Hiroyuki; Yamada, Tomohiro; Mori, Yoshihide

2016-06-01

Adenoid cystic carcinoma (SGC) is a common type of salivary gland cancer (SGC). Surgery is the first treatment choice because chemoradiotherapy is usually not effective. Therefore, new treatment modalities are urgently needed. In this study, it was investigated whether the estrogen axis could be a treatment target or not. Adenoid cystic carcinoma (ACC) ACCM cells, were used. The specific cell line lacks estrogen receptor (ER). ER was introduced in ACCM cells, and the effect of 17β-estradiol (E2) was investigated on cell proliferation, cell-cycle distribution, and cell motility. E2 induced cell proliferation, and the S-phase fraction increased in a dose-dependent manner. Cell motility was also up-regulated compared to control cells. The estrogen/ER system up-regulated malignant phenotypes in ER-positive ACC, and hormone therapy may have a potential as effective treatment for this malignancy. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Estrogen Biology: New Insights into GPER Function and Clinical Opportunities

PubMed Central

Prossnitz, Eric R.; Barton, Matthias

2014-01-01

Estrogens play an important role in the regulation of normal physiology, aging and many disease states. Although the nuclear estrogen receptors have classically been described to function as ligand-activated transcription factors mediating genomic effects in hormonally regulated tissues, more recent studies reveal that estrogens also mediate rapid signaling events traditionally associated with G protein-coupled receptors. The G protein-coupled estrogen receptor GPER (formerly GPR30) has now become recognized as a major mediator of estrogen’s rapid cellular effects throughout the body. With the discovery of selective synthetic ligands for GPER, both agonists and antagonists, as well as the use of GPER knockout mice, significant advances have been made in our understanding of GPER function at the cellular, tissue and organismal levels. In many instances, the protective/beneficial effects of estrogen are mimicked by selective GPER agonism and are absent or reduced in GPER knockout mice, suggesting an essential or at least parallel role for GPER in the actions of estrogen. In this review, we will discuss recent advances and our current understanding of the role of GPER and certain drugs such as SERMs and SERDs in physiology and disease. We will also highlight novel opportunities for clinical development towards GPER-targeted therapeutics, for molecular imaging, as well as for theranostic approaches and personalized medicine. PMID:24530924

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

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 intracerebroventricular injections of specific agonists and antagonists following blockade of brain aromatase, we show here that brain-derived estrogens acutely facilitate male sexual motivation through the activation of estrogen receptor β interacting with the metabotropic glutamate receptor 1a. This behavioral effect occurring within minutes provides a mechanistic explanation of how an estrogen receptor not intrinsically coupled to intracellular effectors can signal from the membrane to govern behavior in a very rapid fashion. It suggests that different subtypes of estrogen receptors could regulate the motivation versus performance aspects of behavior. PMID:26400941

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 intracerebroventricular injections of specific agonists and antagonists following blockade of brain aromatase, we show here that brain-derived estrogens acutely facilitate male sexual motivation through the activation of estrogen receptor β interacting with the metabotropic glutamate receptor 1a. This behavioral effect occurring within minutes provides a mechanistic explanation of how an estrogen receptor not intrinsically coupled to intracellular effectors can signal from the membrane to govern behavior in a very rapid fashion. It suggests that different subtypes of estrogen receptors could regulate the motivation versus performance aspects of behavior. Copyright © 2015 the authors 0270-6474/15/3313110-14$15.00/0.

Estrogen-related receptor-α (ERRα) deficiency in skeletal muscle impairs regeneration in response to injury

PubMed Central

LaBarge, Samuel; McDonald, Marisa; Smith-Powell, Leslie; Auwerx, Johan; Huss, Janice M.

2014-01-01

The estrogen-related receptor-α (ERRα) regulates mitochondrial biogenesis and glucose and fatty acid oxidation during differentiation in skeletal myocytes. However, whether ERRα controls metabolic remodeling during skeletal muscle regeneration in vivo is unknown. We characterized the time course of skeletal muscle regeneration in wild-type (M-ERRαWT) and muscle-specific ERRα−/− (M-ERRα−/−) mice after injury by intramuscular cardiotoxin injection. M-ERRα−/− mice exhibited impaired regeneration characterized by smaller myofibers with increased centrally localized nuclei and reduced mitochondrial density and cytochrome oxidase and citrate synthase activities relative to M-ERRαWT. Transcript levels of mitochondrial transcription factor A, nuclear respiratory factor-2a, and peroxisome proliferator-activated receptor (PPAR)-γ coactivator (PGC)-1β, were downregulated in the M-ERRα−/− muscles at the onset of myogenesis. Furthermore, coincident with delayed myofiber recovery, we observed reduced muscle ATP content (−45% vs. M-ERRαWT) and enhanced AMP-activated protein kinase (AMPK) activation in M-ERRα−/− muscle. We subsequently demonstrated that pharmacologic postinjury AMPK activation was sufficient to delay muscle regeneration in WT mice. AMPK activation induced ERRα transcript expression in M-ERRαWT muscle and in C2C12 myotubes through induction of the Esrra promoter, indicating that ERRα may control gene regulation downstream of the AMPK pathway. Collectively, these results suggest that ERRα deficiency during muscle regeneration impairs recovery of mitochondrial energetic capacity and perturbs AMPK activity, resulting in delayed myofiber repair.—LaBarge, S., McDonald, M., Smith-Powell, L., Auwerx, J., Huss, J. M. Estrogen-related receptor-α (ERRα) deficiency in skeletal muscle impairs regeneration in response to injury. PMID:24277576

Molecular Cloning, Characterization, and Expression Analysis of an Estrogen Receptor-Related Receptor Homologue in the Cricket, Teleogryllus emma

PubMed Central

He, Hui; Xi, Gengsi; Lu, Xiao

2010-01-01

The estrogen receptor-related receptors (ERRs) are a group of nuclear receptors that were originally identified on the basis of sequence similarity to 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 function and regulation of ERRs in invertebrates are not well understood. A homologue of human ERR was isolated from the cricket Teleogryllus emma (Ohmachi and Matsumura) (Orthoptera: Gryllidae). The full-length cDNA of T. emma ERR, termed TeERR, has 1618 base pair (bp) and contains a 5′?-untranslated region of 140 bp and a 3′?-untranslated region of 272 bp. The open reading frame of TeERR encodes a deduced 401 amino acid peptide with a predicted molecular mass of 45.75 kilodaltons. The results of sequence alignments indicate that the TeERR protein shares an overall identity of 65%–82% with other known ERR homologues, and is most closely related to that of Nasonia vitripennis (Hymenoptera: Pteromalidae) and Apis mellifera (Apidae). Real-time quantitative reverse transcription-polymerase chain reaction was performed to compare the TeERR mRNA expression level at the whole body and gonad during T. emma development. The data revealed that TeERR mRNA is differentially expressed during T. emma development, with the highest expression level in embryos and the lowest in the body of late-instar larvae. The levels of TeERR transcripts also varied throughout gonad development; interestingly testicles had higher higher expression levels than ovaries at every development stage. These results suggest that TeERR has potential significance in the regulation of development in T. emma, due to its expression during different developmental periods. PMID:21265615

Windows of susceptibility and consequences of early life exposures to 17β–estradiol on medaka (Oryzias latipes) reproductive success

USGS Publications Warehouse

Lee Pow, Crystal S. D.; Tilahun, Kedamawit; Creech, Kari; Law, J. Mac; Cope, W. Gregory; Kwak, Thomas J.; Rice, James A.; Aday, D. Derek; Kullman, Seth W.

2017-01-01

Estrogens and estrogen mimics are commonly found in surface waters and are associated with deleterious effects in fish populations. Impaired fertility and fecundity in fish following chronic exposures to estrogens and estrogen mimics during critical windows in development are well documented. However, information regarding differential reproductive effects of exposure within defined developmental stages remains sparse. In this study, reproductive capacity was assessed in Japanese medaka (Oryzias latipes) after exposure to two concentrations of 17β–estradiol (E2β; 2 ng/L and 50 ng/L) during four distinct stages of development: gonad development, gonad differentiation, development of secondary sex characteristics (SSC) and gametogenesis. Exposure to E2β did not adversely impact survival, hatch success, growth, or genotypic ratios. In contrast, exposure to 50 ng/L E2β during SSC development altered phenotypic ratios and SSC. Exposure to both E2β treatments reduced reproductive capacity (fertility, fecundity) by 7.3–57.4% in adult medaka breeding pairs, with hindrance of SSC development resulting in the largest disruption in breeding capacity (51.6–57.4% decrease) in the high concentration. This study documents differential effects among four critical stages of development and provides insight into factors (window of exposure, exposure concentration and duration of exposure period) contributing to reproductive disruption in fish.

Estradiol-induced gene expression in largemouth bass (Micropterus salmoides)

USGS Publications Warehouse

Bowman, C.J.; Kroll, K.J.; Gross, T.G.; Denslow, N.D.

2002-01-01

Vitellogenin (Vtg) and estrogen receptor (ER) gene expression levels were measured in largemouth bass to evaluate the activation of the ER-mediated pathway by estradiol (E2). Single injections of E2 ranging from 0.0005 to 5 mg/kg up-regulated plasma Vtg in a dose-dependent manner. Vtg and ER mRNAs were measured using partial cDNA sequences corresponding to the C-terminal domain for Vtg and the ligand-binding domain of ER?? sequences. After acute E2-exposures (2 mg/kg), Vtg and ER mRNAs and plasma Vtg levels peaked after 2 days. The rate of ER mRNA accumulation peaked 36-42 h earlier than Vtg mRNA. The expression window for ER defines the primary response to E2 in largemouth bass and that for Vtg a delayed primary response. The specific effect of E2 on other estrogen-regulated genes was tested during these same time windows using differential display RT-PCR. Specific up-regulated genes that are expressed in the same time window as Vtg were ERp72 (a membrane-bound disulfide isomerase) and a gene with homology to an expressed gene identified in zebrafish. Genes that were expressed in a pattern that mimics the ER include the gene for zona radiata protein ZP2, and a gene with homology to an expressed gene found in winter flounder. One gene for fibrinogen ?? was down-regulated and an unidentified gene was transiently up-regulated after 12 h of exposure and returned to basal levels by 48 h. Taken together these studies indicate that the acute molecular response to E2 involves a complex network of responses over time. ?? 2002 Elsevier Science Ireland Ltd. All rights reserved.

Estrogen anti-inflammatory activity on human monocytes is mediated through cross-talk between estrogen receptor ERα36 and GPR30/GPER1.

PubMed

Pelekanou, Vasiliki; Kampa, Marilena; Kiagiadaki, Foteini; Deli, Alexandra; Theodoropoulos, Panayiotis; Agrogiannis, George; Patsouris, Efstratios; Tsapis, Andreas; Castanas, Elias; Notas, George

2016-02-01

Estrogens are known modulators of monocyte/macrophage functions; however, the underlying mechanism has not been clearly defined. Recently, a number of estrogen receptor molecules and splice variants were identified that exert different and sometimes opposing actions. We assessed the expression of estrogen receptors and explored their role in mediating estrogenic anti-inflammatory effects on human primary monocytes. We report that the only estrogen receptors expressed are estrogen receptor-α 36-kDa splice variant and G-protein coupled receptor 30/G-protein estrogen receptor 1, in a sex-independent manner. 17-β-Estradiol inhibits the LPS-induced IL-6 inflammatory response, resulting in inhibition of NF-κB transcriptional activity. This is achieved via a direct physical interaction of ligand-activated estrogen receptor-α 36-kDa splice variant with the p65 component of NF-κB in the nucleus. G-protein coupled receptor 30/G-protein estrogen receptor 1, which also physically interacts with estrogen receptor-α 36-kDa splice variant, acts a coregulator in this process, because its inhibition blocks the effect of estrogens on IL-6 expression. However, its activation does not mimic the effect of estrogens, on neither IL-6 nor NF-κB activity. Finally, we show that the estrogen receptor profile observed in monocytes is not modified during their differentiation to macrophages or dendritic cells in vitro and is shared in vivo by macrophages present in atherosclerotic plaques. These results position estrogen receptor-α 36-kDa splice variant and G-protein coupled receptor 30 as important players and potential therapeutic targets in monocyte/macrophage-dependent inflammatory processes. © Society for Leukocyte Biology.

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:26023144

Rapid effects of estrogens on short-term memory: Possible mechanisms.

PubMed

Paletta, Pietro; Sheppard, Paul A S; Matta, Richard; Ervin, Kelsy S J; Choleris, Elena

2018-06-01

Estrogens affect learning and memory through rapid and delayed mechanisms. Here we review studies on rapid effects on short-term memory. Estradiol rapidly improves social and object recognition memory, spatial memory, and social learning when administered systemically. The dorsal hippocampus mediates estrogen rapid facilitation of object, social and spatial short-term memory. The medial amygdala mediates rapid facilitation of social recognition. The three estrogen receptors, α (ERα), β (ERβ) and the G-protein coupled estrogen receptor (GPER) appear to play different roles depending on the task and brain region. Both ERα and GPER agonists rapidly facilitate short-term social and object recognition and spatial memory when administered systemically or into the dorsal hippocampus and facilitate social recognition in the medial amygdala. Conversely, only GPER can facilitate social learning after systemic treatment and an ERβ agonist only rapidly improved short-term spatial memory when given systemically or into the hippocampus, but also facilitates social recognition in the medial amygdala. Investigations into the mechanisms behind estrogens' rapid effects on short term memory showed an involvement of the extracellular signal-regulated kinase (ERK) and the phosphoinositide 3-kinase (PI3K) kinase pathways. Recent evidence also showed that estrogens interact with the neuropeptide oxytocin in rapidly facilitating social recognition. Estrogens can increase the production and/or release of oxytocin and other neurotransmitters, such as dopamine and acetylcholine. Therefore, it is possible that estrogens' rapid effects on short-term memory may occur through the regulation of various neurotransmitters, although more research is need on these interactions as well as the mechanisms of estrogens' actions on short-term memory. Copyright © 2018 Elsevier Inc. All rights reserved.

International Union of Basic and Clinical Pharmacology. XCVII. G Protein-Coupled Estrogen Receptor and Its Pharmacologic Modulators.

PubMed

Prossnitz, Eric R; Arterburn, Jeffrey B

2015-07-01

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. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Insights into significant pathways and gene interaction networks underlying breast cancer cell line MCF-7 treated with 17β-estradiol (E2).

PubMed

Huan, Jinliang; Wang, Lishan; Xing, Li; Qin, Xianju; Feng, Lingbin; Pan, Xiaofeng; Zhu, Ling

2014-01-01

Estrogens are known to regulate the proliferation of breast cancer cells and to alter their cytoarchitectural and phenotypic properties, but the gene networks and pathways by which estrogenic hormones regulate these events are only partially understood. We used global gene expression profiling by Affymetrix GeneChip microarray analysis, with KEGG pathway enrichment, PPI network construction, module analysis and text mining methods to identify patterns and time courses of genes that are either stimulated or inhibited by estradiol (E2) in estrogen receptor (ER)-positive MCF-7 human breast cancer cells. Of the genes queried on the Affymetrix Human Genome U133 plus 2.0 microarray, we identified 628 (12h), 852 (24h) and 880 (48 h) differentially expressed genes (DEGs) that showed a robust pattern of regulation by E2. From pathway enrichment analysis, we found out the changes of metabolic pathways of E2 treated samples at each time point. At 12h time point, the changes of metabolic pathways were mainly focused on pathways in cancer, focal adhesion, and chemokine signaling pathway. At 24h time point, the changes were mainly enriched in neuroactive ligand-receptor interaction, cytokine-cytokine receptor interaction and calcium signaling pathway. At 48 h time point, the significant pathways were pathways in cancer, regulation of actin cytoskeleton, cell adhesion molecules (CAMs), axon guidance and ErbB signaling pathway. Of interest, our PPI network analysis and module analysis found that E2 treatment induced enhancement of PRSS23 at the three time points and PRSS23 was in the central position of each module. Text mining results showed that the important genes of DEGs have relationship with signal pathways, such as ERbB pathway (AREG), Wnt pathway (NDP), MAPK pathway (NTRK3, TH), IP3 pathway (TRA@) and some transcript factors (TCF4, MAF). Our studies highlight the diverse gene networks and metabolic and cell regulatory pathways through which E2 operates to achieve its widespread effects on breast cancer cells. © 2013 Elsevier B.V. All rights reserved.

Epigenetic regulation of estrogen-dependent memory

PubMed Central

Fortress, Ashley M.; Frick, Karyn M.

2014-01-01

Hippocampal memory formation is highly regulated by post-translational histone modifications and DNA methylation. Accordingly, these epigenetic processes play a major role in the effects of modulatory factors, such as sex steroid hormones, on hippocampal memory. Our laboratory recently demonstrated that the ability of the potent estrogen 17β-estradiol (E2) to enhance hippocampal-dependent novel object recognition memory in ovariectomized female mice requires ERK-dependent histone H3 acetylation and DNA methylation in the dorsal hippocampus. Although these data provide valuable insight into the chromatin modifications that mediate the memory-enhancing effects of E2, epigenetic regulation of gene expression is enormously complex. Therefore, more research is needed to fully understand how E2 and other hormones employ epigenetic alterations to shape behavior. This review discusses the epigenetic alterations shown thus far to regulate hippocampal memory, briefly reviews the effects of E2 on hippocampal function, and describes in detail our work on epigenetic regulation of estrogenic memory enhancement. PMID:24878494

Various Regulatory Modes for Circadian Rhythmicity and Sexual Dimorphism in the Non-Neuronal Cardiac Cholinergic System.

PubMed

Oikawa, Shino; Kai, Yuko; Mano, Asuka; Ohata, Hisayuki; Nemoto, Takahiro; Kakinuma, Yoshihiko

2017-08-01

Cardiomyocytes possess a non-neuronal cardiac cholinergic system (NNCCS) regulated by a positive feedback system; however, its other regulatory mechanisms remain to be elucidated, which include the epigenetic control or regulation by the female sex steroid, estrogen. Here, the NNCCS was shown to possess a circadian rhythm; its activity was upregulated in the light-off phase via histone acetyltransferase (HAT) activity and downregulated in the light-on phase. Disrupting the circadian rhythm altered the physiological choline acetyltransferase (ChAT) expression pattern. The NNCCS circadian rhythm may be regulated by miR-345, independently of HAT, causing decreased cardiac ChAT expression. Murine cardiac ChAT expression and ACh contents were increased more in female hearts than in male hearts. This upregulation was downregulated by treatment with the estrogen receptor antagonist tamoxifen, and in contrast, estrogen reciprocally regulated cardiac miR-345 expression. These results suggest that the NNCCS is regulated by the circadian rhythm and is affected by sexual dimorphism.

Epigenetic regulation of estrogen-dependent memory.

PubMed

Fortress, Ashley M; Frick, Karyn M

2014-10-01

Hippocampal memory formation is highly regulated by post-translational histone modifications and DNA methylation. Accordingly, these epigenetic processes play a major role in the effects of modulatory factors, such as sex steroid hormones, on hippocampal memory. Our laboratory recently demonstrated that the ability of the potent estrogen 17β-estradiol (E2) to enhance hippocampal-dependent novel object recognition memory in ovariectomized female mice requires ERK-dependent histone H3 acetylation and DNA methylation in the dorsal hippocampus. Although these data provide valuable insight into the chromatin modifications that mediate the memory-enhancing effects of E2, epigenetic regulation of gene expression is enormously complex. Therefore, more research is needed to fully understand how E2 and other hormones employ epigenetic alterations to shape behavior. This review discusses the epigenetic alterations shown thus far to regulate hippocampal memory, briefly reviews the effects of E2 on hippocampal function, and describes in detail our work on epigenetic regulation of estrogenic memory enhancement. Copyright © 2014 Elsevier Inc. All rights reserved.

Identifying a Mechanism for Crosstalk Between the Estrogen and Glucocorticoid Receptors | Center for Cancer Research

Cancer.gov

Estrogen has long been known to play important roles in the development and progression of breast cancer. Its receptor (ER), a member of the steroid receptor family, binds to estrogen response elements (EREs) in DNA and regulates gene transcription. More recently, another steroid receptor family member, the glucocorticoid receptor (GR), has been implicated in breast cancer

G Protein-Coupled Estrogen Receptor (GPER) Expression in Normal and Abnormal Endometrium

PubMed Central

Lessey, Bruce A.; Taylor, Robert N.; Wang, Wei; Bagchi, Milan K.; Yuan, Lingwen; Scotchie, Jessica; Fritz, Marc A.; Young, Steven L.

2012-01-01

Rapid estrogen effects are mediated by membrane receptors, and evidence suggests a role for both a membrane-associated form of estrogen receptor alpha (ESR1; ERα) and G-protein coupled receptor 30 (GPER; GPR30). Considering estrogen’s importance in endometrial physiology and endometriosis pathophysiology, we hypothesized that GPER could be involved in both cyclic changes in endometrial estrogen action and that aberrant expression might be seen in the eutopic endometrium of women with endometriosis. Using real-time reverse transcriptase–polymerase chain reaction (RT-PCR) and immunohistochemical analysis of normal endometrium, endometrial samples demonstrated cycle-regulated expression of GPER, with maximal expression in the proliferative phase. Eutopic and ectopic endometrium from women with endometriosis overexpressed GPER as compared to eutopic endometrium of normal participants. Ishikawa cells, an adenocarcinoma cell line, expressed GPER, with increased expression upon treatment with estrogen or an ESR1 agonist, but not with a GPER-specific agonist. Decreased expression was seen in Ishikawa cells stably transfected with progesterone receptor A. Together, these data suggest that normal endometrial GPER expression is cyclic and regulated by nuclear estrogen and progesterone receptors, while expression is dysregulated in endometriosis. PMID:22378861

Characterization of an estrogen-responsive element implicated in regulation of the rainbow trout estrogen receptor gene.

PubMed

Le Dréan, Y; Lazennec, G; Kern, L; Saligaut, D; Pakdel, F; Valotaire, Y

1995-08-01

We previously reported that the expression of the rainbow trout estrogen receptor (rtER) gene is markedly increased by estradiol (E2). In this paper, we have used transient transfection assays with reporter plasmids expressing chloramphenicol acetyl transferase (CAT), linked to 5' flanking regions of the rtER gene promoter, to identify cis-elements responsible for E2 inducibility. Deletion analysis localized an estrogen-responsive element (ERE), at position +242, with one mutation on the first base compared with the consensus sequence. This element confers estrogen responsiveness to CAT reporter linked to both the herpes simplex virus thymidine kinase promoter and the homologous rtER promoter. Moreover, using a 0.2 kb fragment of the rtER promoter encompassing the ERE and the rtER DNA binding domain obtained from a bacterial expression system, DNase I footprinting experiments demonstrated a specific protection covering 20 bp (+240/+260) containing the ERE sequence. Based on these studies, we believe that this ERE sequence, identified in the rtER gene promoter, may be a major cis-acting element involved in the regulation of the gene by estrogen.

Estrogen regulates histone deacetylases to prevent cardiac hypertrophy

PubMed Central

Pedram, Ali; Razandi, Mahnaz; Narayanan, Ramesh; Dalton, James T.; McKinsey, Timothy A.; Levin, Ellis R.

2013-01-01

The development and progression of cardiac hypertrophy often leads to heart failure and death, and important modulators of hypertrophy include the histone deacetylase proteins (HDACs). Estrogen inhibits cardiac hypertrophy and progression in animal models and humans. We therefore investigated the influence of 17-β-estradiol on the production, localization, and functions of prohypertrophic (class I) and antihypertrophic (class II) HDACs in cultured neonatal rat cardiomyocytes. 17-β-Estradiol or estrogen receptor β agonists dipropylnitrile and β-LGND2 comparably suppressed angiotensin II–induced HDAC2 (class I) production, HDAC-activating phosphorylation, and the resulting prohypertrophic mRNA expression. In contrast, estrogenic compounds derepressed the opposite effects of angiotensin II on the same parameters for HDAC4 and 5 (class II), resulting in retention of these deacetylases in the nucleus to inhibit hypertrophic gene expression. Key aspects were confirmed in vivo from the hearts of wild-type but not estrogen receptor β (ERβ) gene–deleted mice administered angiotensin II and estrogenic compounds. Our results identify a novel dual regulation of cardiomyocyte HDACs, shown here for the antihypertrophic sex steroid acting at ERβ. This mechanism potentially supports using ERβ agonists as HDAC modulators to treat cardiac disease. PMID:24152730

Epigenetic activation of the prostaglandin receptor EP4 promotes resistance to endocrine therapy for breast cancer

PubMed Central

Hiken, Jeffrey F.; McDonald, James I.; Decker, Keith F.; Sanchez, Cesar; Hoog, Jeremy; VanderKraats, Nathan D.; Jung, Kyle L.; Akinhanmi, Margaret; Rois, Lisa E.; Ellis, Matthew J.; Edwards, John R.

2016-01-01

Approximately 75% of breast cancers express estrogen receptor α (ERα) and depend on estrogen signals for continued growth. Aromatase inhibitors (AIs) prevent estrogen production and inhibit estrogen receptor signaling, resulting in decreased cancer recurrence and mortality. Advanced tumors treated with AIs almost always develop resistance to these drugs via the up-regulation of alternative growth signals. The mechanisms that drive this resistance—especially epigenetic events that alter gene expression—are however not well understood. Genome-wide DNA methylation and expression analysis of cell line models of acquired aromatase inhibitor resistance indicated that prostaglandin E2 receptor 4 (PTGER4) is up-regulated after demethylation in resistant cells. Knockdown and inhibitor studies demonstrate that PTGER4 is essential for estrogen independent growth. Our exploratory analysis of downstream signaling indicates that PTGER4 likely promotes AI resistance via ligand independent activation of the ERα-cofactor CARM1. We believe that we have discovered a novel epigenetic mechanism for altering cell signaling and acquiring endocrine therapy resistance. Our findings indicate that PTGER4 is a potential drug target in AI resistant cancers. Additionally, the epigenetic component of PTGER4 regulation suggests that further study of PTGER4 may yield valuable insights into how DNA methylation-targeted diagnoses and treatments can improve AI resistant breast cancer treatment. PMID:27869171

Comparison of metabolic ratios of urinary estrogens between benign and malignant thyroid tumors in postmenopausal women

PubMed Central

2013-01-01

Background Estrogen metabolism may be associated with the pathophysiological development of papillary thyroid carcinoma (PTC). Methods To evaluate the differential estrogen metabolism between benign and malignant PTCs, estrogen profiling by gas chromatography–mass spectrometry was applied to urine samples from postmenopausal patients with 9 benign tumors and 18 malignant stage I and III/IV PTCs. Results The urinary concentration of 2-methoxyestradiol was significantly lower in the stage I malignant patients (3.5-fold; P < 0.025) than in the benign group. The metabolic ratios of 16α-OH-estrone/estrone and estriol/estradiol, which are responsible for 16α-hydroxylase activity, were increased more than 2.5-fold in the advanced-stage malignant PTC (P < 0.02 each). The more than 6.2-fold decrease in the urinary 2-/16α-hydroxylase ratio in stage III/IV malignant PTC was consistent with the ratio in postmenopausal patients with endocrine gland cancers. In addition, reductive 17β-hydroxysteroid dehydrogenase (17β-HSD; estradiol/estrone or estriol/16α-OH-estrone) was present at significantly higher levels in subjects with stage III/IV malignant PTCs than in benign subjects (>3.5-fold difference; P < 0.002). In particular, the estriol/16α-OH-estrone ratio differentiated between the benign and early-stage malignant patients (P < 0.01). Conclusions Increased 16α-hydroxylation and/or a decreased 2-/16α-ratio, as well increased reductive 17β-HSD, with regard to estrogen metabolism could provide potential biomarkers. The devised profiles could be useful for differentiating malignant thyroid carcinomas from benign adenomas in postmenopausal women. PMID:24156385

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-β reactivity at the glandular epithelium, while the group treated with EST showed immunoreactivity at the glandular, luminal, and stromal epithelium. Conclusion GBR phenolics moderately regulate the expression of ER-β, HSP70, and IL-4 receptor genes, and gave a positive immunoreaction to ER-β antigen in the uterus. ASG regulates the expression of CaBP9k and IL-4 receptor genes, and ORZ regulates the expression of the CaBP9k gene, while GABA at 100 mg/kg regulates the expression of the HSP70 gene. GBR and its bioactives might have an effect on estrogen-regulated genes in the uterus of rats. PMID:24324328

Regulation of sexual odor preference by sex steroids in the posterodorsal medial amygdala in female rats.

PubMed

Fujiwara, Masaya; Nitta, Asano; Chiba, Atsuhiko

2016-06-01

Our previous study in male rats demonstrated that bilateral administration of flutamide, an androgen receptor (AR) antagonist, into the posterodorsal medial amygdala (MePD) increased the time sniffing male odors to as high as that sniffing estrous odors, eliminating the preference for estrous odors over male odors. This made us speculate that under blockade of AR in the MePD, testosterone-derived estrogen acting on the same brain region arouses interest in male odors which is otherwise suppressed by concomitant action of androgen. In cyclic female rats, endogenous androgen has been thought to be involved in inhibitory regulation of estrogen-activated sexual behavior. Thus, in the present study, we investigated the possibility that in female rats the arousal of interest in male odors is also normally regulated by both estrogen and androgen acting on the MePD, as predicted by our previous study in male rats. Implantation of either the estrogen receptor blocker tamoxifen (TX) or a non-aromatizable androgen 5α-dihydrotestosterone (DHT) into the MePD of ovariectomized, estrogen-primed female rats eliminated preference for male odors over estrous odors by significantly decreasing the time sniffing male odors to as low as that sniffing estrous odors. The subsequent odor discrimination tests confirmed that the DHT and TX administration did not impair the ability to discriminate between male and estrous odors. These results suggest that in estrous female rats estrogen action in the MePD plays critical roles in the expression of the preference for male odors while androgen action in the same brain region interferes with the estrogen action. Copyright © 2016 Elsevier Inc. All rights reserved.

GPER is involved in the regulation of the estrogen-metabolizing CYP1B1 enzyme in breast cancer

PubMed Central

Cirillo, Francesca; Pellegrino, Michele; Malivindi, Rocco; Rago, Vittoria; Avino, Silvia; Muto, Luigina; Dolce, Vincenza; Vivacqua, Adele; Rigiracciolo, Damiano Cosimo; De Marco, Paola; Sebastiani, Anna; Abonante, Sergio; Nakajima, Miki; Lappano, Rosamaria; Maggiolini, Marcello

2017-01-01

The cytochrome P450 1B1 (CYP1B1) is a heme-thiolate monooxygenase involved in both estrogen biosynthesis and metabolism. For instance, CYP1B1 catalyzes the hydroxylation of E2 leading to the production of 4-hydroxyestradiol that may act as a potent carcinogenic agent. In addition, CYP1B1 is overexpressed in different tumors including breast cancer. In this scenario, it is worth mentioning that CYP1B1 expression is triggered by estrogens through the estrogen receptor (ER)α in breast cancer cells. In the present study, we evaluated whether the G protein estrogen receptor namely GPER may provide an alternate route toward the expression and function of CYP1B1 in ER-negative breast cancer cells, in main players of the tumor microenvironment as cancer associated fibroblasts (CAFs) that were obtained from breast cancer patients, in CAFs derived from a cutaneous metastasis of an invasive mammary ductal carcinoma and in breast tumor xenografts. Our results show that GPER along with the EGFR/ERK/c-Fos transduction pathway can lead to CYP1B1 regulation through the involvement of a half-ERE sequence located within the CYP1B1 promoter region. As a biological counterpart, we found that both GPER and CYP1B1 mediate growth effects in vitro and in vivo. Altogether, our data suggest that estrogens in ER-negative cell contexts may engage the alternate GPER signaling toward CYP1B1 regulation. Estrogen-CYP1B1 landscape via GPER should be taken into account in setting novel pharmacological approaches targeting breast cancer development. PMID:29290975

GPER is involved in the regulation of the estrogen-metabolizing CYP1B1 enzyme in breast cancer.

PubMed

Cirillo, Francesca; Pellegrino, Michele; Malivindi, Rocco; Rago, Vittoria; Avino, Silvia; Muto, Luigina; Dolce, Vincenza; Vivacqua, Adele; Rigiracciolo, Damiano Cosimo; De Marco, Paola; Sebastiani, Anna; Abonante, Sergio; Nakajima, Miki; Lappano, Rosamaria; Maggiolini, Marcello

2017-12-05

The cytochrome P450 1B1 (CYP1B1) is a heme-thiolate monooxygenase involved in both estrogen biosynthesis and metabolism. For instance, CYP1B1 catalyzes the hydroxylation of E2 leading to the production of 4-hydroxyestradiol that may act as a potent carcinogenic agent. In addition, CYP1B1 is overexpressed in different tumors including breast cancer. In this scenario, it is worth mentioning that CYP1B1 expression is triggered by estrogens through the estrogen receptor (ER)α in breast cancer cells. In the present study, we evaluated whether the G protein estrogen receptor namely GPER may provide an alternate route toward the expression and function of CYP1B1 in ER-negative breast cancer cells, in main players of the tumor microenvironment as cancer associated fibroblasts (CAFs) that were obtained from breast cancer patients, in CAFs derived from a cutaneous metastasis of an invasive mammary ductal carcinoma and in breast tumor xenografts. Our results show that GPER along with the EGFR/ERK/c-Fos transduction pathway can lead to CYP1B1 regulation through the involvement of a half-ERE sequence located within the CYP1B1 promoter region. As a biological counterpart, we found that both GPER and CYP1B1 mediate growth effects in vitro and in vivo . Altogether, our data suggest that estrogens in ER-negative cell contexts may engage the alternate GPER signaling toward CYP1B1 regulation. Estrogen-CYP1B1 landscape via GPER should be taken into account in setting novel pharmacological approaches targeting breast cancer development.

Estrogen levels regulate the subcellular distribution of phosphorylated Akt in hippocampal CA1 dendrites.

PubMed

Znamensky, Vladimir; Akama, Keith T; McEwen, Bruce S; Milner, Teresa A

2003-03-15

In addition to genomic pathways, estrogens may regulate gene expression by activating specific signal transduction pathways, such as that involving phosphatidylinositol 3-kinase (PI3-K) and the subsequent phosphorylation of Akt (protein kinase B). The Akt pathway regulates various cellular events, including the initiation of protein synthesis. Our previous studies showed that synaptogenesis in hippocampal CA1 pyramidal cell dendritic spines is highest when brain estrogen levels are highest. To address the role of Akt in this process, the subcellular distribution of phosphorylated Akt immunoreactivity (pAkt-I) in the hippocampus of female rats across the estrous cycle and male rats was analyzed by light microscopy (LM) and electron microscopy (EM). By LM, the density of pAkt-I in stratum radiatum of CA1 was significantly higher in proestrus rats (or in estrogen-supplemented ovariectomized females) compared with diestrus, estrus, or male rats. By EM, pAkt-I was found throughout the shafts and in select spines of stratum radiatum dendrites. Quantitative ultrastructural analysis identifying pAkt-I with immunogold particles revealed that proestrus rats compared with diestrus, estrus, and male rats contained significantly higher pAkt-I associated with (1) dendritic spines (both cytoplasm and plasmalemma), (2) spine apparati located within 0.1 microm of dendritic spine bases, (3) endoplasmic reticula and polyribosomes in the cytoplasm of dendritic shafts, and (4) the plasmalemma of dendritic shafts. These findings suggest that estrogens may regulate spine formation in CA1 pyramidal neurons via Akt-mediated signaling events.

Estrogenic gper signaling regulates mir144 expression in cancer cells and cancer-associated fibroblasts (cafs).

PubMed

Vivacqua, Adele; De Marco, Paola; Santolla, Maria Francesca; Cirillo, Francesca; Pellegrino, Michele; Panno, Maria Luisa; Abonante, Sergio; Maggiolini, Marcello

2015-06-30

MicroRNAs (miRNAs) are small non coding RNA molecules that play a crucial role in several pathophysiological conditions, including cancer. The stimulation of hormone-sensitive tumors by estrogens are mediated by estrogen receptor (ER)α and G protein estrogen receptor (GPER). Previous studies have reported that ERα regulates miRNA expression, while this ability of GPER remains to be elucidated. Here, we demonstrate that in SkBr3 breast cancer and HepG2 hepatocarcinoma cells, 17β-estradiol (E2) and the selective GPER ligand G-1 induce miR144 expression through GPER and the involvement of the PI3K/ERK1/2/Elk1 transduction pathway. Moreover, we show that E2 and G-1 down-regulate through miR144 the onco-suppressor Runx1 and increase cell cycle progression. The capability of E2 and G-1 in triggering the induction of miR144 and the down-regulation of Runx1 was also confirmed in cancer-associated fibroblasts (CAFs) that are main components of the tumor microenvironment driving cancer progression. Further confirming these results, Runx1 protein levels were found decreased in tumor xenografts upon G-1 treatment. On the basis of our findings miR144 and Runx1 may be included among the oncotargets of GPER action. Moreover, the present data provide new insights regarding the ability of estrogens to trigger the GPER/miR144/Runx1 transduction pathway toward the stimulation of cancer progression.

pS2 and PAI-1 in ovarian cancer: correlation to pathohistological parameters.

PubMed

Speiser, P; Mayerhofer, K; Kucera, E; Roch, G; Mittelböck, M; Gitsch, G; Zeillinger, R

1997-01-01

The estrogen regulated pS2 protein and the Plasminogen Activator Inhibitor type 1 (PAI-1) have been reported as important tumor parameters both in breast and in ovarian cancer. We analysed the cytosolic concentrations of pS2 in 111 ovarian carcinoma and the cytosolic concentrations of PAI-1 in 104 ovarian cancers by RIA and ELISA. Using a cut-off level of 2 ng/mg protein we found 27% pS2+ tumors. We observed 42% PAI-1+ tumors using a out-off level of 1 ng/mg. We found a statistically significant decline in the pS2 status corresponding with an increase in the PAI-1 status from well to poor differentiation grade. The highest levels of pS2 and the lowest levels of PAI-1 were measured in borderline carcinoma. Significantly higher concentrations of pS2 were measured in mucinous over serous carcinoma. We found no significant correlation between PAI-1 and histologic subtypes, or between pS2 or PAI-1 and estrogen receptor status, progesterone receptor status, age and tumor stage. To conclude, we found pS2 and PAI-1 concentrations to be correlated with the grade of differentiation. A correlation between protein status and histologic subtypes could be observed for pS2 but not for PAI-1.

Municipal wastewater affects adipose deposition in male mice and increases 3T3-L1 cell differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biasiotto, Giorgio; Zanella, Isabella; Department of Molecular and Translational Medicine, University of Brescia, Brescia

Trace concentration of EDs (endocrine disrupting compounds) in water bodies caused by wastewater treatment plant effluents is a recognized problem for the health of aquatic organisms and their potential to affect human health. In this paper we show that continuous exposure of male mice from early development to the adult life (140 days) to unrestricted drinking of wastewater collected from a municipal sewage treatment plant, is associated with an increased adipose deposition and weight gain during adulthood because of altered body homeostasis. In parallel, bisphenol A (BPA) at the administration dose of 5 μg/kg/body weight, shows an increasing effect onmore » total body weight and fat mass. In vitro, a solid phase extract (SPE) of the wastewater (eTW), caused stimulation of 3T3-L1 adipocyte differentiation at dilutions of 0.4 and 1 % in the final culture medium which contained a concentration of BPA of 40 nM and 90 nM respectively. Pure BPA also promoted adipocytes differentiation at the concentration of 50 and 80 μM. BPA effect in 3T3-L1 cells was associated to the specific activation of the estrogen receptor alpha (ERα) in undifferentiated cells and the estrogen receptor beta (ERβ) in differentiated cells. BPA also activated the Peroxisome Proliferator Activated Receptor gamma (PPARγ) upregulating a minimal 3XPPARE luciferase reporter and the PPARγ-target promoter of the aP2 gene in adipose cells, while it was not effective in preadipocytes. The pure estrogen receptor agonist diethylstilbestrol (DES) played an opposite action to that of BPA inhibiting PPARγ activity in adipocytes, preventing cell differentiation, activating ERα in preadipocytes and inhibiting ERα and ERβ regulation in adipocytes. The results of this work show that the drinking of chemically-contaminated wastewater promotes fat deposition in male mice and that EDs present in sewage are likely responsible for this effect through a nuclear receptor-mediated mechanism. - Highlights: • Sewage watewaters (TW) sampled from a Municipal Treatment Sewage Plant are biologically active in mice and in vitro. • In male mice TW promotes an increase in adipose mass deposition following exposure from foetal to adult life. A similar effect is produced by BPA. • The expression of key genes of the adipose metabolism is increased in epidydimal fat both by TW and BPA. • An extract from the TW which concentrated the contained chemicals by a factor of 1000, is able to stimulate 3T3-L1 adipocyte differentiation. • The major chemicals contained in the TW, bisphenol A and nonylphenol, are able to promote adipocyte differentiation at the low environmentally relevant doses as are found in the TW.« less

Blockage of progestin physiology disrupts ovarian differentiation in XX Nile tilapia (Oreochromis niloticus).

PubMed

Zhou, Linyan; Luo, Feng; Fang, Xuelian; Charkraborty, Tapas; Wu, Limin; Wei, Jing; Wang, Deshou

2016-04-22

Previous studies indicated that maturation inducing hormone, 17α, 20β-Dihydroxy-4-pregnen-3-one (DHP), probably through nuclear progestin receptor (Pgr), might be involved in spermatogenesis and oogenesis in fish. To further elucidate DHP actions in teleostean ovarian differentiation, we analyzed the expression of pgr in the ovary of Nile tilapia (Oreochromis niloticus), and performed RU486 (a synthetic Pgr antagonist) treatment in XX fish from 5 days after hatching (dah) to 120 dah. Tilapia Pgr was abundantly expressed in the follicular cells surrounding oocytes at 30 and 90 dah. Continuous RU486 treatment led to the blockage of oogenesis and masculinization of somatic cells in XX fish. Termination of RU486 treatment and maintenance in normal condition resulted in testicular differentiation, and estrogen compensation in RU486-treated XX fish successfully restored oogenesis. In RU486-treated XX fish, transcript levels of female dominant genes were significantly reduced, while male-biased genes were evidently augmented. Meanwhile, both germ cell mitotic and meiotic markers were substantially reduced. Consistently, estrogen production levels were significantly declined in RU486-treated XX fish. Taken together, our data further proved that DHP, possibly through Pgr, might be essential in the ovarian differentiation and estrogen production in fish. Copyright © 2016 Elsevier Inc. All rights reserved.

Involvements of Estrogen Receptor, Proliferating Cell Nuclear Antigen and p53 in Endometrial Adenocarcinoma Development in Donryu Rats

PubMed Central

Yoshida, Midori; Katsuda, Shin-ichi; Maekawa, Akihiko

2012-01-01

Involvements of estrogen receptor (ER)α, proliferating cell nuclear antigen (PCNA) and p53 in the uterine carcinogenesis process in Donryu rats, a high yield strain of the uterine cancer were investigated immunohistochemically. ERα was expressed in atypical endometrial hyperplasia, accepted as a precancerous lesion of the uterine tumors, as well as well- and in moderately-differentiated endometrial adenocarcinomas, and the intensities of expression were similar to those in the luminal epithelial cells of the atrophic uterus at 15 months of age. The expression, however, was negative in the tumor cells of poorly differentiated type. Good growth of implanted grafts of the poorly-differentiated adenocarcinomas in both sexes with or without gonadectomy supported the estrogen independency of tumor progression to malignancy. PCNA labeling indices were increased with tumor development from atypical hyperplasia to adenocarcinoma. The tumor cells in poorly-differentiated adenocarcinomas were positive for p53 positive but negative for p21 expression, suggesting accumulation of mutated p53. These results indicate that the consistent ERα expression is involved in initiation and promotion steps of uterine carcinogenesis, but not progression. In addition, PCNA is related to tumor development and the expression of mutated p53 might be a late event during endometrial carcinogenesis. PMID:23345926

Gender, sex hormones and pulmonary hypertension

PubMed Central

Austin, Eric D.; Lahm, Tim; West, James; Tofovic, Stevan P.; Johansen, Anne Katrine; MacLean, Margaret R.; Alzoubi, Abdallah; Oka, Masahiko

2013-01-01

Most subtypes of pulmonary arterial hypertension (PAH) are characterized by a greater susceptibility to disease among females, although females with PAH appear to live longer after diagnosis. While this “estrogen paradoxȍ of enhanced female survival despite increased female susceptibility remains a mystery, recent progress has begun to shed light upon the interplay of sex hormones, the pathogenesis of pulmonary hypertension, and the right ventricular response to stress. For example, emerging data in humans and experimental models suggest that estrogens or differential sex hormone metabolism may modify disease risk among susceptible subjects, and that estrogens may interact with additional local factors such as serotonin to enhance the potentially damaging chronic effects of estrogens on the pulmonary vasculature. Regardless, it remains unclear why not all estrogenic compounds behave equally, nor why estrogens appear to be protective in certain settings but detrimental in others. The contribution of androgens and other compounds, such as dehydroepiandrosterone, to pathogenesis and possibly treatment must be considered as well. In this review, we will discuss the recent understandings on how estrogens, estrogen metabolism, dehydroepiandrosterone, and additional susceptibility factors may all contribute to the pathogenesis or potentially to the treatment of pulmonary hypertension, by evaluating current human, cell-based, and experimental model data. PMID:24015330

Hormonal Contraception, Body Water Balance and Thermoregulation

DTIC Science & Technology

1997-10-01

Schreiber, and M. D. Lindheimer. Effect of ovarian sex steroids on osmoregulation and vasopressin secretion in the rat. Am. J. Physiol. 250 (Endocrinol...two widely used oral contraceptive preparations differ significantly in their estrogenicity. Estrogens have potent effects on the regulation of body...water balance (1, 4), so these two forms of oral contraceptive pills may differ in their effects on water regulation, and hence on physical performance

In vitro toxicological effects of estrogenic mycotoxins on human placental cells: Structure activity relationships

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prouillac, Caroline, E-mail: c.prouillac@vetagro-sup.fr; Koraichi, Farah; Videmann, Bernadette

2012-03-15

Zearalenone (ZEN) is a non-steroid estrogen mycotoxin produced by numerous strains of Fusarium which commonly contaminate cereals. After oral administration, ZEN is reduced via intestinal and hepatic metabolism to α- and β-zearalenol (αZEL and βZEL). These reduced metabolites possess estrogenic properties, αZEL showing the highest affinity for ERs. ZEN and reduced metabolites cause hormonal effects in animals, such as abnormalities in the development of the reproductive tract and mammary gland in female offspring, suggesting a fetal exposure to these contaminants. In our previous work, we have suggested the potential impact of ZEN on placental cells considering this organ as amore » potential target of xenobiotics. In this work, we first compared the in vitro effects of αZEL and βΖΕL on cell differentiation to their parental molecule on human trophoblast (BeWo cells). Secondly, we investigated their molecular mechanisms of action by investigating the expression of main differentiation biomarkers and the implication of nuclear receptor by docking prediction. Conversely to ZEN, reduced metabolites did not induce trophoblast differentiation. They also induced significant changes in ABC transporter expression by potential interaction with nuclear receptors (LXR, PXR, PR) that could modify the transport function of placental cells. Finally, the mechanism of ZEN differentiation induction seemed not to involve nuclear receptor commonly involved in the differentiation process (PPARγ). Our results demonstrated that in spite of structure similarities between ZEN, αZEL and βZEL, toxicological effects and toxicity mechanisms were significantly different for the three molecules. -- Highlights: ► ZEN and metabolites have differential effect on trophoblast differentiation. ► ZEN and metabolites have differential effect on ABC transporter expression. ► ZEN and metabolites effects involved nuclear receptors interaction.« less

A sensitive amplified sensor based on improved carbon paste electrode with 1-methyl-3-octylimidazolium tetrafluoroborate and ZnO/CNTs nanocomposite for differential pulse voltammetric analysis of raloxifene

NASA Astrophysics Data System (ADS)

Cheraghi, Somaye; Taher, Mohammad Ali; Karimi-Maleh, Hassan

2017-10-01

In this work, we suggested a carbon paste electrode improved with 1-methyl-3-octylimidazolium tetrafluoroborate (1-M-3-OITFB) and ZnO/CNTs nanocomposite (1-M-3-OITFB/ZnO/CNTs/CPE) for electrochemical determination of raloxifene (RXF) as a non-steroidal selective estrogen receptor regulator. The cyclic and differential pulse voltammetric methods were apply for investigation of RXF electrochemical response at a surface of 1-M-3-OITFB/ZnO/CNTs/CPE. Under the best experimental conditions, the 1-M-3-OITFB/ZnO/CNTs/CPE showed a wide linear dynamic range of 0.08 - 400.0 μM. We detected a detection limit of 0.04 μM for RXF analysis using differential pulse voltammetric method (DPV). The 1-M-3-OITFB/ZnO/CNTs/CPE showed high performance ability to RXF analysis in trace amounts on pharmaceutical and clinical preparations.

RARRES3 suppresses breast cancer lung metastasis by regulating adhesion and differentiation

PubMed Central

Morales, Mònica; Arenas, Enrique J; Urosevic, Jelena; Guiu, Marc; Fernández, Esther; Planet, Evarist; Fenwick, Robert Bryn; Fernández-Ruiz, Sonia; Salvatella, Xavier; Reverter, David; Carracedo, Arkaitz; Massagué, Joan; Gomis, Roger R

2014-01-01

In estrogen receptor-negative breast cancer patients, metastatic relapse usually occurs in the lung and is responsible for the fatal outcome of the disease. Thus, a better understanding of the biology of metastasis is needed. In particular, biomarkers to identify patients that are at risk of lung metastasis could open the avenue for new therapeutic opportunities. Here we characterize the biological activity of RARRES3, a new metastasis suppressor gene whose reduced expression in the primary breast tumors identifies a subgroup of patients more likely to develop lung metastasis. We show that RARRES3 downregulation engages metastasis-initiating capabilities by facilitating adhesion of the tumor cells to the lung parenchyma. In addition, impaired tumor cell differentiation due to the loss of RARRES3 phospholipase A1/A2 activity also contributes to lung metastasis. Our results establish RARRES3 downregulation as a potential biomarker to identify patients at high risk of lung metastasis who might benefit from a differentiation treatment in the adjuvant programme. PMID:24867881

GPR30 mediates anorectic estrogen-induced STAT3 signaling in the hypothalamus.

PubMed

Kwon, Obin; Kang, Eun Seok; Kim, Insook; Shin, Sora; Kim, Mijung; Kwon, Somin; Oh, So Ra; Ahn, Young Soo; Kim, Chul Hoon

2014-11-01

Estrogen plays an important role in the control of energy balance in the hypothalamus. Leptin-independent STAT3 activation (i.e., tyrosine(705)-phosphorylation of STAT3, pSTAT3) in the hypothalamus is hypothesized as the primary mechanism of the estrogen-induced anorexic response. However, the type of estrogen receptor that mediates this regulation is unknown. We investigated the role of the G protein-coupled receptor 30 (GPR30) in estradiol (E2)-induced STAT3 activation in the hypothalamus. Regulation of STAT3 activation by E2, G-1, a specific agonist of GPR30 and G-15, a specific antagonist of GPR30 was analyzed in vitro and in vivo. Effect of GPR30 activation on eating behavior was analyzed in vivo. E2 stimulated pSTAT3 in cells expressing GPR30, but not expressing estrogen receptor ERα and ERβ. G-1 induced pSTAT3, and G-15 inhibited E2-induced pSTAT3 in primary cultures of hypothalamic neurons. A cerebroventricular injection of G-1 increased pSTAT3 in the arcuate nucleus of mice, which was associated with a decrease in food intake and body weight gain. These results suggest that GPR30 is the estrogen receptor that mediates the anorectic effect of estrogen through the STAT3 pathway in the hypothalamus. Copyright © 2014 Elsevier Inc. All rights reserved.

Development of a Novel Tissue Specific Aromatase Activity Regulation Therapeutic Method

DTIC Science & Technology

2009-09-01

Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Estrogen is essential for normal growth and development of the female ...the ovaries and other tissues of the body using an enzyme called aromatase. Once women have reached menopause, the ovaries no longer produce estrogen...Introduction Estrogen is essential for normal growth and development of the female reproductive system, including breast tissue, and lifetime

Developmental exposure to low-dose estrogenic endocrine disruptors alters sex differences in exploration and emotional responses in mice.

PubMed

Gioiosa, Laura; Fissore, Elena; Ghirardelli, Giorgia; Parmigiani, Stefano; Palanza, Paola

2007-09-01

Estrogenic endocrine disruptors (EEDs) are naturally occurring or man-made compounds present in the environment that are able to bind to estrogen receptors and interfere with normal cellular development in target organs and tissues. There is mounting evidence that EEDs can interfere with the processes of sexual differentiation of brain and behavior in different animal models. We investigated the effects of maternal exposure to EEDs, at concentrations within the range of human exposure and not patently teratogenic, on behavioral responses of male and female house mice (Mus musculus domesticus) before and after puberty. Pregnant dams were trained to spontaneously drink daily doses of corn oil with or without the estrogenic plastic derivative, bisphenol A (BPA 10 microg/kg), or the estrogenic insecticide methoxychlor (MXC 20 microg/kg) from gestation day 11 to postpartum day 8. Their male and female offspring were examined at different ages to examine several components of explorative and emotional behaviors in 3 experimental paradigms: a novelty test before puberty and, as adults, a free-exploratory open-field test and the elevated plus maze test. The main results are sex differences in control mice on a number of behavioral responses at both ages and in all experimental paradigms, while perinatal exposure to BPA or MXC decreased or eliminated such sex differences. The present findings are evidence of long-term consequences of developmental exposure to BPA and MXC on neurobehavioral development and suggest a differential effect of low-dose exposure to these estrogenic chemicals in males and females.

Differential and directional estrogenic signaling pathways induced by enterolignans and their precursors

PubMed Central

Zhu, Yun; Kawaguchi, Kayoko; Kiyama, Ryoiti

2017-01-01

Mammalian lignans or enterolignans are metabolites of plant lignans, an important category of phytochemicals. Although they are known to be associated with estrogenic activity, cell signaling pathways leading to specific cell functions, and especially the differences among lignans, have not been explored. We examined the estrogenic activity of enterolignans and their precursor plant lignans and cell signaling pathways for some cell functions, cell cycle and chemokine secretion. We used DNA microarray-based gene expression profiling in human breast cancer MCF-7 cells to examine the similarities, as well as the differences, among enterolignans, enterolactone and enterodiol, and their precursors, matairesinol, pinoresinol and sesamin. The profiles showed moderate to high levels of correlation (R values: 0.44 to 0.81) with that of estrogen (17β-estradiol or E2). Significant correlations were observed among lignans (R values: 0.77 to 0.97), and the correlations were higher for cell functions related to enzymes, signaling, proliferation and transport. All the enterolignans/precursors examined showed activation of the Erk1/2 and PI3K/Akt pathways, indicating the involvement of rapid signaling through the non-genomic estrogen signaling pathway. However, when their effects on specific cell functions, cell cycle progression and chemokine (MCP-1) secretion were examined, positive effects were observed only for enterolactone, suggesting that signals are given in certain directions at a position closer to cell functions. We hypothesized that, while estrogen signaling is initiated by the enterolignans/precursors examined, their signals are differentially and directionally modulated later in the pathways, resulting in the differences at the cell function level. PMID:28152041

Differential prooxidative effects of the green tea polyphenol, (-)-epigallocatechin-3-gallate, in normal and oral cancer cells are related to differences in sirtuin 3 signaling.

PubMed

Tao, Ling; Park, Jong-Yung; Lambert, Joshua D

2015-02-01

We have previously reported that the green tea catechin, (-)-epigallocatechin-3-gallate (EGCG), can induce oxidative stress in oral cancer cells but exerts antioxidant effects in normal cells. Here, we report that these differential prooxidative effects are associated with sirtuin 3 (SIRT3), an important mitochondrial redox modulator. EGCG rapidly induced mitochondria-localized reactive oxygen species in human oral squamous carcinoma cells (SCC-25, SCC-9) and premalignant leukoplakia cells (MSK-Leuk1), but not in normal human gingival fibroblast cells (HGF-1). EGCG suppressed SIRT3 mRNA and protein expression, as well as, SIRT3 activity in SCC-25 cells, whereas it increased SIRT3 activity in HGF-1 cells. EGCG selectively decreased the nuclear localization of the estrogen-related receptor α (ERRα), the transcription factor regulating SIRT3 expression, in SCC-25 cells. This indicates that EGCG may regulate SIRT3 transcription in oral cancer cells via ERRα. EGCG also differentially modulated the mRNA expressions of SIRT3-associated downstream targets including glutathione peroxidase 1 and superoxide dismutase 2 in normal and oral cancer cells. SIRT3 represents a novel potential target through which EGCG exerts differential prooxidant effects in cancer and normal cells. Our results provide new biomarkers to be further explored in animal studies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Selective estrogen receptor modulators differentially alter the immune response of gilthead seabream juveniles.

PubMed

Rodenas, M C; Cabas, I; García-Alcázar, A; Meseguer, J; Mulero, V; García-Ayala, A

2016-05-01

17α-ethynylestradiol (EE2), a synthetic estrogen used in oral contraceptives and hormone replacement therapy, tamoxifen (Tmx), a selective estrogen-receptor modulator used in hormone replacement therapy, and G1, a G protein-coupled estrogen receptor (GPER) selective agonist, differentially increased the hepatic vitellogenin (vtg) gene expression and altered the immune response in adult gilthead seabream (Sparus aurata L.) males. However, no information exists on the effects of these compounds on the immune response of juveniles. This study aims, for the first time, to investigate the effects of the dietary intake of EE2, Tmx or G1 on the immune response of gilthead seabream juveniles and the capacity of the immune system of the specimens to recover its functionality after ceasing exposures (recovery period). The specimens were immunized with hemocyanin in the presence of aluminium adjuvant 1 (group A) or 120 (group B) days after the treatments ceased (dpt). The results indicate that EE2 and Tmx, but not G1, differentially promoted a transient alteration in hepatic vtg gene expression. Although all three compounds did not affect the production of reactive oxygen intermediates, they inhibited the induction of interleukin-1β (il1b) gene expression after priming. Interestingly, although Tmx increased the percentage of IgM-positive cells in both head kidney and spleen during the recovery period, the antibody response of vaccinated fish varied depending on the compound used and when the immunization was administered. Taken together, our results suggest that these compounds differentially alter the capacity of fish to respond to infection during ontogeny and, more interestingly, that the adaptive immune response remained altered to an extent that depends on the compound. Copyright © 2016 Elsevier Ltd. All rights reserved.

E2-mediated cathepsin D (CTSD) activation involves looping of distal enhancer elements.

PubMed

Bretschneider, Nancy; Kangaspeska, Sara; Seifert, Martin; Reid, George; Gannon, Frank; Denger, Stefanie

2008-08-01

Estrogen receptor alpha (ERalpha) is a ligand dependent transcription factor that regulates the expression of target genes through interacting with cis-acting estrogen response elements (EREs). However, only a minority of ERalpha binding sites are located within the proximal promoter regions of responsive genes. Here we report the characterization of an ERE located 9kbp upstream of the TSS of the cathepsin D gene (CTSD) that up-regulates CTSD expression upon estrogen stimulation in MCF-7 cells. Using ChIP, we show recruitment of ERalpha and phosphorylated PolII at the CTSD distal enhancer region. Moreover, we determine the kinetics of transient CpG methylation on the promoter region of CTSD and for the first time, at a distal enhancer element. We show that ERalpha is crucial for long-distance regulation of CTSD expression involving a looping mechanism.

Identification of differentially expressed genes in human breast cancer cells induced by 4-hydroxyltamoxifen and elucidation of their pathophysiological relevance and mechanisms

PubMed Central

Fang, Qi; Yao, Shuang; Luo, Guanghua; Zhang, Xiaoying

2018-01-01

While tamoxifen (TAM) is used for treating estrogen receptor (ER)a-positive breast cancer patients, its anti-breast cancer mechanisms are not completely elucidated. This study aimed to examine effects of 4-hydroxyltamoxifen (4-OH-TAM) on ER-positive (ER+) breast cancer MCF-7 cell growth and gene expression profiles. MCF-7 cell growth was inhibited by 4-OH-TAM dose-dependently with IC50 of 29 μM. 332 genes were up-regulated while 320 genes were down-regulated. The mRNA levels of up-regulated genes including STAT1, STAT2, EIF2AK2, TGM2, DDX58, PARP9, SASH1, RBL2 and USP18 as well as down-regulated genes including CCDN1, S100A9, S100A8, ANXA1 and PGR were confirmed by quantitative real-time PCR (qRT-PCR). In human breast tumor tissues, mRNA levels of EIF2Ak2, USP18, DDX58, RBL2, STAT2, PGR, S1000A9, and CCND1 were significantly higher in ER+- than in ER--breast cancer tissues. The mRNA levels of EIF2AK2, TGM2, USP18, DDX58, PARP9, STAT2, STAT1, PGR and CCND1 were all significantly higher in ER+-tumor tissues than in their corresponding tumor-adjacent tissues. These genes, except PGR and CCND1 which were down-regulated, were also up-regulated in ER+ MCF-7 cells by 4-OH-TAM. Total 14 genes mentioned above are involved in regulation of cell proliferation, apoptosis, cell cycles, and estrogen and interferon signal pathways. Bioinformatics analysis also revealed other novel and important regulatory factors that are associated with these genes and involved in the mentioned functional processes. This study has paved a foundation for elucidating TAM anti-breast cancer mechanisms in E2/ER-dependent and independent pathways. PMID:29416786

Identification of differentially expressed genes in human breast cancer cells induced by 4-hydroxyltamoxifen and elucidation of their pathophysiological relevance and mechanisms.

PubMed

Fang, Qi; Yao, Shuang; Luo, Guanghua; Zhang, Xiaoying

2018-01-05

While tamoxifen (TAM) is used for treating estrogen receptor (ER)a-positive breast cancer patients, its anti-breast cancer mechanisms are not completely elucidated. This study aimed to examine effects of 4-hydroxyltamoxifen (4-OH-TAM) on ER-positive (ER + ) breast cancer MCF-7 cell growth and gene expression profiles. MCF-7 cell growth was inhibited by 4-OH-TAM dose-dependently with IC 50 of 29 μM. 332 genes were up-regulated while 320 genes were down-regulated. The mRNA levels of up-regulated genes including STAT1, STAT2, EIF2AK2, TGM2, DDX58, PARP9, SASH1, RBL2 and USP18 as well as down-regulated genes including CCDN1, S100A9, S100A8, ANXA1 and PGR were confirmed by quantitative real-time PCR (qRT-PCR). In human breast tumor tissues, mRNA levels of EIF2Ak2, USP18, DDX58, RBL2, STAT2, PGR, S1000A9, and CCND1 were significantly higher in ER + - than in ER - -breast cancer tissues. The mRNA levels of EIF2AK2, TGM2, USP18, DDX58, PARP9, STAT2, STAT1, PGR and CCND1 were all significantly higher in ER + -tumor tissues than in their corresponding tumor-adjacent tissues. These genes, except PGR and CCND1 which were down-regulated, were also up-regulated in ER + MCF-7 cells by 4-OH-TAM. Total 14 genes mentioned above are involved in regulation of cell proliferation, apoptosis, cell cycles, and estrogen and interferon signal pathways. Bioinformatics analysis also revealed other novel and important regulatory factors that are associated with these genes and involved in the mentioned functional processes. This study has paved a foundation for elucidating TAM anti-breast cancer mechanisms in E2/ER-dependent and independent pathways.

Estrogen receptor-alpha promotes alternative macrophage activation during cutaneous repair.

PubMed

Campbell, Laura; Emmerson, Elaine; Williams, Helen; Saville, Charis R; Krust, Andrée; Chambon, Pierre; Mace, Kimberly A; Hardman, Matthew J

2014-09-01

Efficient local monocyte/macrophage recruitment is critical for tissue repair. Recruited macrophages are polarized toward classical (proinflammatory) or alternative (prohealing) activation in response to cytokines, with tight temporal regulation crucial for efficient wound repair. Estrogen acts as a potent anti-inflammatory regulator of cutaneous healing. However, an understanding of estrogen/estrogen receptor (ER) contribution to macrophage polarization and subsequent local effects on wound healing is lacking. Here we identify, to our knowledge previously unreported, a role whereby estrogen receptor α (ERα) signaling preferentially polarizes macrophages from a range of sources to an alternative phenotype. Cell-specific ER ablation studies confirm an in vivo role for inflammatory cell ERα, but not ERβ, in poor healing associated with an altered cytokine profile and fewer alternatively activated macrophages. Furthermore, we reveal intrinsic changes in ERα-deficient macrophages, which are unable to respond to alternative activation signals in vitro. Collectively, our data reveal that inflammatory cell-expressed ERα promotes alternative macrophage polarization, which is beneficial for timely healing. Given the diverse physiological roles of ERs, these findings will likely be of relevance to many pathologies involving excessive inflammation.

Histone H2A.Z is essential for estrogen receptor signaling

PubMed Central

Gévry, Nicolas; Hardy, Sara; Jacques, Pierre-Étienne; Laflamme, Liette; Svotelis, Amy; Robert, François; Gaudreau, Luc

2009-01-01

Incorporation of H2A.Z into the chromatin of inactive promoters has been shown to poise genes for their expression. Here we provide strong evidence that H2A.Z is incorporated into the promoter regions of estrogen receptor (ERα) target genes only upon gene induction, and that, in a cyclic pattern. Moreover, members of the human H2A.Z-depositing complex, p400, also follow the same gene recruitment kinetics as H2A.Z. Importantly, cellular depletion of H2A.Z or p400 leads to a severe defect in estrogen signaling, including loss of estrogen-specific cell proliferation. We find that incorporation of H2A.Z within TFF1 promoter chromatin allows nucleosomes to adopt preferential positions along the DNA translational axis. Finally, we provide evidence that H2A.Z is essential to allow estrogen-responsive enhancer function. Taken together, our results provide strong mechanistic insight into how H2A.Z regulates ERα-mediated gene expression and provide a novel link between H2A.Z–p400 and ERα-dependent gene regulation and enhancer function. PMID:19515975

The choroid plexus harbors a circadian oscillator modulated by estrogens.

PubMed

Quintela, Telma; Albuquerque, Tânia; Lundkvist, Gabriella; Carmine Belin, Andrea; Talhada, Daniela; Gonçalves, Isabel; Carro, Eva; Santos, Cecília R A

2018-02-01

The suprachiasmatic nucleus (SCN) of the hypothalamus is considered the master circadian oscillator in mammals. However, extra-SCN structures in the brain also display daily rhythms. Recently, we have demonstrated that the choroid plexus (CP) expresses core clock genes that are subjected to circadian regulation in a sex-dependent manner. By using CP explants cultured from female knock-in mice carrying the Period-luciferase transgene, we show that CP exhibits endogenous circadian rhythms of PERIOD2::LUCIFERASE expression. Furthermore, we demonstrate that estrogen declines following ovariectomy modulates the daily rhythm expression of Bmal1, Per1 and Per2 in female rat CP, corroborating data obtained in experiments where rat CP epithelial cell (CPEC) cultures were incubated with 17β-estradiol (E2). The molecular mechanism underlying these effects was also investigated, and we provide evidence that the estrogen receptor (ER) mediates the response of clock genes to E2. In conclusion, our study proves that the CP harbors a circadian oscillator that is modulated by estrogens and demonstrates that E2 regulation occurs through an estrogen-receptor-dependent mechanism.

THE ROLE OF ANDROGENS AND ESTROGENS IN THE DEVELOPMENT OF BRAIN AND PERIPHERAL NERVOUS SYSTEM: APPROACHES TO DEVELOPING ANIMAL MODELS FOR SEXUALLY DIMORPHIC BEHAVIORS

EPA Science Inventory

This presentation provides an overview of research on the effects of hormonally active chemicals on sexual differentiation of the brain including (a) research on the role of androgens and estrogens in the development of the brain and peripheral nervous system, (b) approaches to d...

Reproductive effects in birds exposed to pesticides and industrial chemicals.

PubMed Central

Fry, D M

1995-01-01

Environmental contamination by agricultural chemicals and industrial waste disposal results in adverse effects on reproduction of exposed birds. The diversity of pollutants results in physiological effects at several levels, including direct effects on breeding adults as well as developmental effects on embryos. The effects on embryos include mortality or reduced hatchability, failure of chicks to thrive (wasting syndrome), and teratological effects producing skeletal abnormalities and impaired differentiation of the reproductive and nervous systems through mechanisms of hormonal mimicking of estrogens. The range of chemical effects on adult birds covers acute mortality, sublethal stress, reduced fertility, suppression of egg formation, eggshell thinning, and impaired incubation and chick rearing behaviors. The types of pollutants shown to cause reproductive effects include organochlorine pesticides and industrial pollutants, organophosphate pesticides, petroleum hydrocarbons, heavy metals, and in a fewer number of reports, herbicides, and fungicides. o,p'-DDT, polychlorinated biphenyls (PCBs), and mixtures of organochlorines have been identified as environmental estrogens affecting populations of gulls breeding in polluted "hot spots" in southern California, the Great Lakes, and Puget Sound. Estrogenic organochlorines represent an important class of toxicants to birds because differentiation of the avian reproductive system is estrogen dependent. PMID:8593865

Progesterone action in breast, uterine, and ovarian cancers

PubMed Central

Diep, Caroline H.; Daniel, Andrea R.; Mauro, Laura J.; Knutson, Todd P.; Lange, Carol A.

2015-01-01

Progesterone and progesterone receptors (PR) are essential for the development and cyclical regulation of hormone-responsive tissues including the breast and reproductive tract. Altered functions of PR isoforms contribute to the pathogenesis of tumors that arise in these tissues. In the breast, progesterone acts in concert with estrogen to promote proliferative and pro-survival gene programs. In sharp contrast, progesterone inhibits estrogen-driven growth in the uterus and protects the ovary from neoplastic transformation. Progesterone-dependent actions and associated biology in diverse tissues and tumors are mediated by two progesterone receptor isoforms, PR-A and PR-B. These isoforms are subject to altered transcriptional activity or expression levels, differential cross-talk with growth factor signaling pathways, and distinct post-translational modifications and cofactor binding partners. Herein, we summarize and discuss the recent literature focused on progesterone and PR isoform-specific actions in breast, uterine, and ovarian cancers. Understanding the complexity of context-dependent PR actions in these tissues is critical to developing new models that will allow us to advance our knowledge base with the goal of revealing novel and efficacious therapeutic regimens for these hormone-responsive diseases. PMID:25587053

Estrogenic Endocrine Disrupting Chemicals Influencing NRF1 Regulated Gene Networks in the Development of Complex Human Brain Diseases.

PubMed

Preciados, Mark; Yoo, Changwon; Roy, Deodutta

2016-12-13

During the development of an individual from a single cell to prenatal stages to adolescence to adulthood and through the complete life span, humans are exposed to countless environmental and stochastic factors, including estrogenic endocrine disrupting chemicals. Brain cells and neural circuits are likely to be influenced by estrogenic endocrine disruptors (EEDs) because they strongly dependent on estrogens. In this review, we discuss both environmental, epidemiological, and experimental evidence on brain health with exposure to oral contraceptives, hormonal therapy, and EEDs such as bisphenol-A (BPA), polychlorinated biphenyls (PCBs), phthalates, and metalloestrogens, such as, arsenic, cadmium, and manganese. Also we discuss the brain health effects associated from exposure to EEDs including the promotion of neurodegeneration, protection against neurodegeneration, and involvement in various neurological deficits; changes in rearing behavior, locomotion, anxiety, learning difficulties, memory issues, and neuronal abnormalities. The effects of EEDs on the brain are varied during the entire life span and far-reaching with many different mechanisms. To understand endocrine disrupting chemicals mechanisms, we use bioinformatics, molecular, and epidemiologic approaches. Through those approaches, we learn how the effects of EEDs on the brain go beyond known mechanism to disrupt the circulatory and neural estrogen function and estrogen-mediated signaling. Effects on EEDs-modified estrogen and nuclear respiratory factor 1 (NRF1) signaling genes with exposure to natural estrogen, pharmacological estrogen-ethinyl estradiol, PCBs, phthalates, BPA, and metalloestrogens are presented here. Bioinformatics analysis of gene-EEDs interactions and brain disease associations identified hundreds of genes that were altered by exposure to estrogen, phthalate, PCBs, BPA or metalloestrogens. Many genes modified by EEDs are common targets of both 17 β-estradiol (E2) and NRF1. Some of these genes are involved with brain diseases, such as Alzheimer's Disease (AD), Parkinson's Disease, Huntington's Disease, Amyotrophic Lateral Sclerosis, Autism Spectrum Disorder, and Brain Neoplasms. For example, the search of enriched pathways showed that top ten E2 interacting genes in AD- APOE , APP , ATP5A1 , CALM1 , CASP3 , GSK3B , IL1B , MAPT , PSEN2 and TNF- underlie the enrichment of the Kyoto Encyclopedia of Genes and Genomes (KEGG) AD pathway. With AD, the six E2-responsive genes are NRF1 target genes: APBB2 , DPYSL2 , EIF2S1 , ENO1 , MAPT , and PAXIP1 . These genes are also responsive to the following EEDs: ethinyl estradiol ( APBB2 , DPYSL2 , EIF2S1 , ENO1 , MAPT , and PAXIP1 ), BPA ( APBB2 , EIF2S1 , ENO1 , MAPT , and PAXIP1 ), dibutyl phthalate (DPYSL2, EIF2S1, and ENO1), diethylhexyl phthalate ( DPYSL2 and MAPT ). To validate findings from Comparative Toxicogenomics Database (CTD) curated data, we used Bayesian network (BN) analysis on microarray data of AD patients. We observed that both gender and NRF1 were associated with AD. The female NRF1 gene network is completely different from male human AD patients. AD-associated NRF1 target genes- APLP1 , APP , GRIN1 , GRIN2B , MAPT , PSEN2 , PEN2 , and IDE -are also regulated by E2. NRF1 regulates targets genes with diverse functions, including cell growth, apoptosis/autophagy, mitochondrial biogenesis, genomic instability, neurogenesis, neuroplasticity, synaptogenesis, and senescence. By activating or repressing the genes involved in cell proliferation, growth suppression, DNA damage/repair, apoptosis/autophagy, angiogenesis, estrogen signaling, neurogenesis, synaptogenesis, and senescence, and inducing a wide range of DNA damage, genomic instability and DNA methylation and transcriptional repression, NRF1 may act as a major regulator of EEDs-induced brain health deficits. In summary, estrogenic endocrine disrupting chemicals-modified genes in brain health deficits are part of both estrogen and NRF1 signaling pathways. Our findings suggest that in addition to estrogen signaling, EEDs influencing NRF1 regulated communities of genes across genomic and epigenomic multiple networks may contribute in the development of complex chronic human brain health disorders.

Estrogens of multiple classes and their role in mental health disease mechanisms.

PubMed

Watson, Cheryl S; Alyea, Rebecca A; Cunningham, Kathryn A; Jeng, Yow-Jiun

2010-08-09

Gender and sex hormones can influence a variety of mental health states, including mood, cognitive development and function, and vulnerability to neurodegenerative diseases and brain damage. Functions of neuronal cells may be altered by estrogens depending upon the availability of different physiological estrogenic ligands; these ligands and their effects vary with life stages, the genetic or postgenetic regulation of receptor levels in specific tissues, or the intercession of competing nonphysiological ligands (either intentional or unintentional, beneficial to health or not). Here we review evidence for how different estrogens (physiological and environmental/dietary), acting via different estrogen receptor subtypes residing in alternative subcellular locations, influence brain functions and behavior. We also discuss the families of receptors and transporters for monoamine neurotransmitters and how they may interact with the estrogenic signaling pathways.

Estrogenic modulation of auditory processing: a vertebrate comparison

PubMed Central

Caras, Melissa L.

2013-01-01

Sex-steroid hormones are well-known regulators of vocal motor behavior in several organisms. A large body of evidence now indicates that these same hormones modulate processing at multiple levels of the ascending auditory pathway. The goal of this review is to provide a comparative analysis of the role of estrogens in vertebrate auditory function. Four major conclusions can be drawn from the literature: First, estrogens may influence the development of the mammalian auditory system. Second, estrogenic signaling protects the mammalian auditory system from noise- and age-related damage. Third, estrogens optimize auditory processing during periods of reproductive readiness in multiple vertebrate lineages. Finally, brain-derived estrogens can act locally to enhance auditory response properties in at least one avian species. This comparative examination may lead to a better appreciation of the role of estrogens in the processing of natural vocalizations and may provide useful insights toward alleviating auditory dysfunctions emanating from hormonal imbalances. PMID:23911849

Regulation of the intronic promoter of rat estrogen receptor alpha gene, responsible for truncated estrogen receptor product-1 expression.

PubMed

Schausi, Diane; Tiffoche, Christophe; Thieulant, Marie-Lise

2003-07-01

We have characterized the intronic promoter of the rat estrogen receptor (ER) alpha gene, responsible for the lactotrope-specific truncated ER product (TERP)-1 isoform expression. Transcriptional regulation was investigated by transient transfections using 5'-deletion constructs. TERP promoter constructs were highly active in MMQ cells, a pure lactotrope cell line, whereas a low basal activity was detected in alphaT3-1 gonadotrope cells or in COS-7 monkey kidney cells. Serial deletion analysis revealed that 1) a minimal -693-bp region encompassing the TATA box is sufficient to allow lactotrope-specific expression; 2) the promoter contains strong positive cis-acting elements both in the distal and proximal regions, and 3) the region spanning the -1698/-1194 region includes repressor elements. Transient transfection studies, EMSAs, and gel shifts demonstrated that estrogen activates the TERP promoter via an estrogen-responsive element (ERE1) located within the proximal region. Mutation of ERE1 site completely abolishes the estradiol-dependent transcription, indicating that ERE1 site is sufficient to confer estrogen responsiveness to TERP promoter. In addition, ERalpha action was synergized by transfection of the pituitary-specific factor Pit-1. EMSAs showed that a single Pit-1 DNA binding element in the vicinity of the TATA box is sufficient to confer response by the TERP promoter. In conclusion, we demonstrated, for the first time, that TERP promoter regulation involves ERE and Pit-1 cis-elements and corresponding trans-acting factors, which could play a role in the physiological changes that occur in TERP-1 transcription in lactotrope cells.

Regulation of expression of hyperalgesic priming by estrogen receptor alpha in the rat

PubMed Central

Ferrari, Luiz F.; Araldi, Dionéia; Levine, Jon D.

2017-01-01

Hyperalgesic priming, a sexually dimorphic model of transition to chronic pain, is expressed as prolongation of prostaglandin E2 (PGE2)-induced hyperalgesia by the activation of an additional pathway including an autocrine mechanism at the plasma membrane. The autocrine mechanism involves the transport of cAMP to the extracellular space, and its conversion to AMP and adenosine, by ecto-5′phosphodiesterase and ecto-5′nucleotidase, respectively. The end product, adenosine, activates A1 receptors, producing delayed onset prolongation of PGE2 hyperalgesia. We tested the hypothesis that the previously reported, estrogen-dependent, sexual dimorphism observed in the induction of priming is present in the mechanisms involved in its expression, as a regulatory effect on ecto-5′nucleotidase by estrogen receptor alpha (EsRα), in female rats. In the primed paw AMP hyperalgesia was dependent on conversion to adenosine, being prevented by ecto-5′nucleotidase inhibitor AMPCP and A1 receptor antagonist DPCPX. To investigate an interaction between EsRα and ecto-5′nucleotidase, we treated primed female rats with ODN antisense or mismatch against EsRα mRNA. While in rats treated with antisense AMP-induced hyperalgesia was abolished, the A1 receptor agonist N6-cyclopentiladenosine (CPA) still produced hyperalgesia. Thus, EsRα interacts with this autocrine pathway at the level of ecto-5′nucleotidase. These results demonstrate a sexually dimorphic mechanism for the expression of priming. Perspective This study presents evidence of an estrogen-dependent mechanism of expression of chronic pain in females, supporting the suggestion that differential targets must be considered when establishing protocols for the treatment of painful conditions in males and females. PMID:28089711

Prostate enlargement in mice due to fetal exposure to low doses of estradiol or diethylstilbestrol and opposite effects at high doses

PubMed Central

Saal, Frederick S. vom; Timms, Barry G.; Montano, Monica M.; Palanza, Paola; Thayer, Kristina A.; Nagel, Susan C.; Dhar, Minati D.; Ganjam, V. K.; Parmigiani, Stefano; Welshons, Wade V.

1997-01-01

On the basis of results of studies using high doses of estrogens, exposure to estrogen during fetal life is known to inhibit prostate development. However, it is recognized in endocrinology that low concentrations of a hormone can stimulate a tissue, while high concentrations can have the opposite effect. We report here that a 50% increase in free-serum estradiol in male mouse fetuses (released by a maternal Silastic estradiol implant) induced a 40% increase in the number of developing prostatic glands during fetal life; subsequently, in adulthood, the number of prostatic androgen receptors per cell was permanently increased by 2-fold, and the prostate was enlarged by 30% (due to hyperplasia) relative to untreated males. However, as the free serum estradiol concentration in male fetuses was increased from 2- to 8-fold, adult prostate weight decreased relative to males exposed to the 50% increase in estradiol. As a model for fetal exposure to man-made estrogens, pregnant mice were fed diethylstilbestrol (DES) from gestation days 11 to 17. Relative to controls, DES doses of 0.02, 0.2, and 2.0 ng per g of body weight per day increased adult prostate weight, whereas a 200-ng-per-g dose decreased adult prostate weight in male offspring. Our findings suggest that a small increase in estrogen may modulate the action of androgen in regulating prostate differentiation, resulting in a permanent increase in prostatic androgen receptors and prostate size. For both estradiol and DES, prostate weight first increased then decreased with dose, resulting in an inverted-U dose-response relationship. PMID:9050904

Inhibin/activin-betaC and -betaE subunits in the Ishikawa human endometrial adenocarcinoma cell line.

PubMed

Kimmich, Tanja; Brüning, Ansgar; Käufl, Stephanie D; Makovitzky, Josef; Kuhn, Christina; Jeschke, Udo; Friese, Klaus; Mylonas, Ioannis

2010-08-01

Inhibins and activins are important regulators of the female reproductive system. Recently, two novel inhibin subunits, named betaC and betaE, have been identified and shown to be expressed in several human tissues. However, only limited data on the expression of these novel inhibin subunits in normal human endometrial tissue and endometrial adenocarcinoma cell lines exist. Samples of proliferative and secretory human endometrium were obtained from five premenopausal, non-pregnant patients undergoing gynecological surgery for benign diseases. Normal endometrial tissue and Ishikawa endometrial adenocarcinoma cell lines were analyzed by immunohistochemistry, immunofluorescence and RT-PCR. Expression of the inhibin betaC and betaE subunits could be demonstrated at the protein level by means of immunohistochemical evaluation and at the transcriptional level by establishing a betaC- and betaE-specific RT-PCR analysis in normal human endometrial tissue and the parental Ishikawa cell line. Interestingly, in a highly de-differentiated subclone of the Ishikawa cell line lacking estrogen receptor expression, the expression of the inhibin-betaC subunit appeared strongly reduced. Here, we show for the first time that the novel inhibin/activin-betaC and -betaE subunits are expressed in normal human endometrium and the estrogen receptor positive human endometrial carcinoma cell line Ishikawa using RT-PCR and immunohistochemical detection methods. Interestingly, the Ishikawa minus cell line (lacking estrogen receptor expression) demonstrated no to minimal expression of the betaC subunit as observed with immunofluorescence and RT-PCR, suggesting a possible hormone- dependency of this subunit in human endometrial cancer cells. Moreover, because the Ishikawa cell line minus is thought to be a more malignant endometrial cell line than its estrogen receptor positive counterpart, inhibin-betaC subunit might be substantially involved in the pathogenesis and malignant transformation in human endometrium.

Control of follicle-stimulating hormone by estradiol and the inhibins: critical role of estradiol at the hypothalamus during the luteal-follicular transition.

PubMed

Welt, Corrine K; Pagan, Yanira L; Smith, Patricia C; Rado, Kimberly B; Hall, Janet E

2003-04-01

To test the hypothesis that estradiol, inhibin A, and inhibin B contribute differentially to FSH negative feedback in specific phases of the menstrual cycle, daily blood samples were obtained across a control cycle and after selective estrogen blockade with tamoxifen. To examine the site of estradiol-negative feedback in control and tamoxifen treatment cycles, early follicular phase GnRH (free alpha-subunit) pulse frequency was assessed in normal women, and FSH levels were examined in GnRH-deficient women in whom hypothalamic output was fixed with GnRH administration. FSH was higher in the early follicular phase in the presence of estrogen receptor blockade (15.7 +/- 3.1 vs. 13.2 +/- 1.9 IU/liter; P < 0.05) but was not increased in the late follicular phase. In the luteal phase, FSH was elevated (10.1 +/- 0.7 vs. 7.3 +/- 0.6 IU/liter; P < 0.01). In normal women, free alpha-subunit pulse frequency increased (7.3 +/- 0.4 vs. 4.8 +/- 0.4 pulses per 8 h; P < 0.003), but in GnRH-deficient women, there was no FSH increase (11.1 +/- 1.6 vs. 12.5 +/- 3.6 IU/liter) in the early follicular phase in the presence of estrogen blockade. In conclusion, estradiol exerts a greater role over inhibin in FSH-negative feedback regulation during the luteal phase and the luteal-follicular transition. In contrast, inhibin A and/or B plays a more critical role as the follicular phase progresses. In addition, these studies support a primary if not exclusive hypothalamic site of estrogen-negative feedback in the early follicular phase.

Proteomic changes during adult stage in pre-optic, hypothalamus, hippocampus and pituitary regions of female rat brain following neonatal exposure to estradiol-17β.

PubMed

Govindaraj, Vijayakumar; Shridharan, Radhika Nagamangalam; Rao, Addicam Jagannadha

2018-05-16

Although neonatal exposure to estrogen or estrogenic compounds results in irreversible changes in the brain function and reproductive abnormalities during adulthood but the underlying mechanisms are still largely unknown. The present study has attempted to compare the protein profiles of sexually dimorphic brain regions of adult female rats which were exposed to estradiol- 17β during neonatal period. The total proteins extracted from pre-optic area (POA), hypothalamus, hippocampus and pituitary of control and neonatally E2 treated female rats was subjected to 2D-SDS-PAGE and differentially expressed proteins were identified by MALDI TOF/TOF-MS. Our results revealed that a total of 21 protein spots which were identified as differentially expressed in all the four regions analyzed; the differential expression was further validated by RT-PCR and western blotting. The differentially expressed proteins such as 14-3-3 zeta/delta (POA), LMNA (hippocampus), Axin2 (hypothalamus), Syntaxin-7 (hippocampus), prolactin and somatotropin (pituitary) which have very important functions in the process of neuronal differentiation, migration, axon outgrowth, formation of dendritic spine density and synaptic plasticity and memory have not been previously reported in association with neonatal estrogen exposure. The affected brain functions are very important for the establishment of sex specific brain morphology and behavior. Our results suggest that the differentially expressed proteins may play an important role in irreversible changes in the brain function as well as reproductive abnormalities observed in the female rats during adulthood. Copyright © 2018 Elsevier Inc. All rights reserved.

HER4 selectively coregulates estrogen stimulated genes associated with breast tumor cell proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Wen; Jones, Frank E., E-mail: fjones3@tulane.edu

2014-01-10

Highlights: •HER4/4ICD is an obligate coactivator for 37% of estrogen regulated genes. •HER4/4ICD coactivated genes selectively regulate estrogen stimulated proliferation. •Estrogen stimulated tumor cell migration occurs independent of HER4/4ICD. •Disrupting HER4/4ICD and ER coactivated gene expression may suppress breast cancer. -- Abstract: The EGFR-family member HER4 undergoes regulated intramembrane proteolysis (RIP) to generate an intracellular domain (4ICD) that functions as a transcriptional coactivator. Accordingly, 4ICD coactivates the estrogen receptor (ER) and associates with ER at target gene promoters in breast tumor cells. However, the extent of 4ICD coactivation of ER and the functional significance of the 4ICD/ER transcriptional complex ismore » unclear. To identify 4ICD coactivated genes we performed a microarray gene expression analysis of β-estradiol treated cells comparing control MCF-7 breast cancer cells to MCF-7 cells where HER4 expression was stably suppressed using a shRNA. In the MCF-7 cell line, β-estradiol significantly stimulated or repressed by 2-fold or more 726 or 53 genes, respectively. Significantly, HER4/4ICD was an obligate coactivator for 277 or 38% of the β-estradiol stimulated genes. Ingenuity Pathway Analysis of β-estradiol regulated genes identified significant associations with multiple cellular functions regulating cellular growth and proliferation, cell cycle progression, cancer metastasis, decreased hypoplasia, tumor cell migration, apoptotic resistance of tumor cells, and increased transcription. Genes coactivated by 4ICD displayed functional specificity by only significantly contributing to cellular growth and proliferation, cell cycle progression, and decreased hypoplasia. In direct concordance with these in situ results we show that HER4 knockdown in MCF-7 cells results in a loss of estrogen stimulated tumor cell proliferation and cell cycle progression, whereas, estrogen stimulated tumor cell migration was unaffected by loss of HER4 expression. In summary, we demonstrate for the first time that a cell surface receptor functions as an obligate ER coactivator with functional specificity associated with breast tumor cell proliferation and cell cycle progression. Nearly 90% of ER positive tumors coexpress HER4, therefore we predict that the majority of breast cancer patients would benefit from a strategy to therapeutic disengage ER/4ICD coregulated tumor cell proliferation.« less

Electrochemical estrogen screen method based on the electrochemical behavior of MCF-7 cells.

PubMed

Li, Jinlian; Song, Jia; Bi, Sheng; Zhou, Shi; Cui, Jiwen; Liu, Jiguang; Wu, Dongmei

2016-08-05

It was an urgent task to develop quick, cheap and accurate estrogen screen method for evaluating the estrogen effect of the booming chemicals. In this study, the voltammetric behavior between the estrogen-free and normal fragmented MCF-7 cell suspensions were compared, and the electrochemical signal (about 0.68V attributed by xanthine and guanine) of the estrogen-free fragmented MCF-7 cell suspension was obviously lower than that of the normal one. The electrochemistry detection of ex-secretion purines showed that the ability of ex-secretion purines of cells sharp decreased due to the removing of endogenous estrogen. The results indicated that the electrochemical signal of MCF-7 cells was related to the level of intracellular estrogen. When the level of intracellular estrogen was down-regulated, the concentrations of the xanthine and hypoxanthine decreased, which led to the electrochemical signal of MCF-7 cells fall. Based on the electrochemical signal, the electrochemical estrogen screen method was established. The estrogen effect of estradiol, nonylphenol and bisphenol A was evaluated with the electrochemical method, and the result was accordant with that of MTT assay. The electrochemical estrogen screen method was simple, quickly, cheap, objective, and it exploits a new way for the evaluation of estrogenic effects of chemicals. Copyright © 2016. Published by Elsevier B.V.

Modulation of hepatocyte growth factor gene expression by estrogen in mouse ovary.

PubMed

Liu, Y; Lin, L; Zarnegar, R

1994-09-01

Hepatocyte growth factor (HGF) is expressed in a variety of tissues and cell types under normal conditions and in response to various stimuli such as tissue injury. In the present study, we demonstrate that the transcription of the HGF gene is stimulated by estrogen in mouse ovary. A single injection of 17 beta-estradiol results in a dramatic and transient elevation of the levels of mouse HGF mRNA. Sequence analysis has found that two putative estrogen responsive elements (ERE) reside at -872 in the 5'-flanking region and at +511 in the first intron, respectively, of the mouse HGF gene. To test whether these ERE elements are responsible for estrogen induction of HGF gene expression, chimeric plasmids containing variable regions of the 5'-flanking sequence of HGF gene and the coding region for chloramphenicol acetyltransferase (CAT) gene were transiently transfected into both human endometrial carcinoma RL 95-2 cells and mouse fibroblast NIH 3T3 cells to assess hormone responsiveness. Transfection results indicate that the ERE elements of the mouse HGF gene can confer estrogen action to either homologous or heterologous promoters. Nuclear protein extracts either from RL95-2 cells transfected with the estrogen receptor expression vector or from mouse liver bound in vitro to ERE elements specifically, as shown by band shift assay. Therefore, our results demonstrate that the HGF gene is transcriptionally regulated by estrogen in mouse ovary; and such regulation is mediated via a direct interaction of the estrogen receptor complex with cis-acting ERE elements identified in the mouse HGF gene.

Determination of the Role of Estrogen Receptors and Estrogen Regulated Genes in B Cell Autoreactivity

DTIC Science & Technology

2011-07-01

Betty Diamond – DOD FINAL REPORT 9 Figure 3: (A) expression of estrogen receptors ERalpha( Esr1 ) and ERbeta (Esr2) in splenic B cells and (B...Urinary 16 OH-Estradiol metabolite in BALB/c and C57BL6 mice. Esr1 0 0.05 0.1 0.15 0.2 Transit. Mature Transit. Mature Transit. Mature Transit. mature P E2

The G protein-coupled estrogen receptor GPER in health and disease

PubMed Central

Prossnitz, Eric R.; Barton, Matthias

2012-01-01

Estrogens mediate profound effects throughout the body, and regulate physiological and pathological processes in both women and men. The decreased incidence of many diseases in premenopausal women is attributed to the presence of 17β-estradiol, the predominant and most potent endogenous estrogen. In addition to endogenous estrogens, however, several manmade and plant-derived molecules also exhibit estrogenic activity. Traditionally, the actions of 17β-estradiol are ascribed to two nuclear estrogen receptors (ERs), ERα and ERβ, which function as ligand-activated transcription factors. However, 17β-estradiol also mediates rapid signaling events via pathways that involve transmembrane ERs, such as G-protein-coupled ER 1, (GPER, formerly known as GPR30). In the past 10 years, GPER has been implicated in both rapid signaling and transcriptional regulation. With the discovery of GPER-selective ligands that can selectively modulate GPER function in cell experiments and preclinical studies, and the use of GPER-knockout mice, many more potential roles for GPER are currently being elucidated. This Review highlights the physiological roles of GPER in the reproductive, nervous, endocrine, immune and cardiovascular systems, as well as its pathological roles in a diverse array of disorders including cancer. GPER is emerging as a novel therapeutic target and prognostic indicator for these diseases. PMID:21844907

The G-protein-coupled estrogen receptor GPER in health and disease.

PubMed

Prossnitz, Eric R; Barton, Matthias

2011-08-16

Estrogens mediate profound effects throughout the body and regulate physiological and pathological processes in both women and men. The low prevalence of many diseases in premenopausal women is attributed to the presence of 17β-estradiol, the predominant and most potent endogenous estrogen. In addition to endogenous estrogens, several man-made and plant-derived molecules, such as bisphenol A and genistein, also exhibit estrogenic activity. Traditionally, the actions of 17β-estradiol are ascribed to two nuclear estrogen receptors (ERs), ERα and ERβ, which function as ligand-activated transcription factors. However, 17β-estradiol also mediates rapid signaling events via pathways that involve transmembrane ERs, such as G-protein-coupled ER 1 (GPER; formerly known as GPR30). In the past 10 years, GPER has been implicated in both rapid signaling and transcriptional regulation. With the discovery of GPER-selective ligands that can selectively modulate GPER function in vitro and in preclinical studies and with the use of Gper knockout mice, many more potential roles for GPER are being elucidated. This Review highlights the physiological roles of GPER in the reproductive, nervous, endocrine, immune and cardiovascular systems, as well as its pathological roles in a diverse array of disorders including cancer, for which GPER is emerging as a novel therapeutic target and prognostic indicator.

[Changes in molecular forms of sex hormone binding globulin during menstrual cycle and menopause].

PubMed

Fonseca, M E; Masón, M; Ochoa, R; Hernández-V, M; Zárate, A

1996-11-01

Sex hormone binding globulin (SHBG) is a glycoprotein that transports mainly androgens and estrogens regulating the amount of free and bound hormone which in turn plays a role in the metabolic balance. It is also known that estrogens increase the hepatic production of SHBG which circulates in various molecular forms containing different amounts of sialic acid as the main component of carbohydrates. In the present work we studied physiological variations of molecular forms of SHBG during the normal menstrual cycle and the menopause. During the follicular phase the form 54 KD was the predominant variant, in the periovulatory period was isomers 90 KD, and during the luteal phase corresponded to both 54 and 90 KD. In the menopause dimeric form of 90 KD corresponded to the major proportion and was present a higher molecular forms of 115-135 KD. Following estrogen therapy the chromatographic profile changed as to that observed during the menstrual cycle. Important changes in the proportion of sialic acid were observed in each of the phases of menstrual cycle and following estrogen replacement. And increase in the amount of sialic acid corresponded to higher estrogen concentrations. It is concluded that SHBG concentrations varies during the menstrual cycle according the estrogen levels which in addition regulates the proportion of molecular forms and sialic acid containt.

Participation of Water in the Binding of Estrogen Receptor with Estrogen Responsive Element in vitro.

PubMed

Zhu, Guo-Zhang; Tang, Guo-Qing; Ruan, Kang-Cheng; Gong, Yue-Ting; Zhang, Yong-Lian

1998-01-01

Many reports have showed that bound water was involved in the interaction between/among the macromolecules. However, it has not been reported whether bound water is also involved in the binding of trans-factors and cis-elements in the regulation of the eukaryotic gene trans-cription or not. Preliminary studies have been made on the effect of bound water on the binding of estrogen receptor with estrogen responsive element in vitro. In the gel retardation assay using the cytosol extract of rat uterus as the supplier of estrogen receptor and 32 bp oligonucleotide containing a concensus vitellogenin A(2) ERE as the probe, various cosolvents, such as glycerol, sucrose, N-dimethylformamide and dimethylsulfoxide, were added respectively to the reaction mixture in varying concentrations to regulate the osmotic pressure. The results indicated that the binding of ER-ERE was enhanced with the increase in the final concentration of these individual cosolvents. On the other hand, when the reaction was carried out under an increasing hydrostatic pressure, the ER-ERE binding was decreased sharply. After decompression the binding of ER-ERE was gradually restored to the normal level with the lapse of time. These results suggested that bound water was directly involved in the binding of ER-ERE and may play an important role in the regulation of the eukaryotic gene transcription.

Estrogen upregulates MICA/B expression in human non-small cell lung cancer through the regulation of ADAM17.

PubMed

Ren, Jing; Nie, Yunzhong; Lv, Mingming; Shen, Sunan; Tang, Ruijing; Xu, Yujun; Hou, Yayi; Zhao, Shuli; Wang, Tingting

2015-11-01

Estrogen is involved in promoting lung cancer cell division and metastasis. MICA and MICB function as ligands for NKG2D, an important immunoreceptor expressed on natural killer (NK) cells. However, whether estrogen regulates MICA/B expression and affects tumor immune escape remains unknown. In this study, we measured the mRNA levels of MICA, MICB and ADAM17in non-small cell lung cancer (NSCLC) cell lines treated with estrogen. Surface expression of MICA/B on LTEP-a2 and A549 was detected using flow cytometry. We demonstrate that both mRNA and secretory protein levels of MICA/B in lung adenocarcinoma cell lines were upregulated by estradiol. Estradiol enhanced the expression of ADAM17, which was associated with the secretion of MICA/B. This secretion of MICA/B downregulated the NKG2D receptor on the surface of NK92 cells and impaired the cytotoxic activity of NK cells. Estradiol enhanced the expression of ADAM17, which was associated with the secretion of MICA/B. Furthermore, a significant correlation between the concentration of estradiol and the expression of MICA was found in tumor tissues of NSCLC patients. Therefore, we conclude that estrogen can regulate the expression and secretion of MICA/B through ADAM17, which helps lung cancer cells escape NKG2D-mediated immune surveillance.

Systems Biology of Metabolic Regulation by Estrogen Receptor Signaling in Breast Cancer.

PubMed

Zhao, Yiru Chen; Madak Erdogan, Zeynep

2016-03-17

With the advent of the -omics approaches our understanding of the chronic diseases like cancer and metabolic syndrome has improved. However, effective mining of the information in the large-scale datasets that are obtained from gene expression microarrays, deep sequencing experiments or metabolic profiling is essential to uncover and then effectively target the critical regulators of diseased cell phenotypes. Estrogen Receptor α (ERα) is one of the master transcription factors regulating the gene programs that are important for estrogen responsive breast cancers. In order to understand to role of ERα signaling in breast cancer metabolism we utilized transcriptomic, cistromic and metabolomic data from MCF-7 cells treated with estradiol. In this report we described generation of samples for RNA-Seq, ChIP-Seq and metabolomics experiments and the integrative computational analysis of the obtained data. This approach is useful in delineating novel molecular mechanisms and gene regulatory circuits that are regulated by a particular transcription factor which impacts metabolism of normal or diseased cells.

Uterine responses to feeding soy protein isolate and treatment with 17β-estradiol differ in ovariectomized female rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronis, Martin J., E-mail: mronis@lsuhsc.edu; Gomez-Acevedo, Horacio; Blackburn, Michael L.

There are concerns regarding reproductive toxicity from consumption of soy foods, including an increased risk of endometriosis and endometrial cancer, as a result of phytoestrogen consumption. In this study, female rats were fed AIN-93G diets made with casein (CAS) or soy protein isolate (SPI) from postnatal day (PND) 30, ovariectomized on PND 50 and infused with 5 μg/kg/d 17β-estradiol (E2) or vehicle. E2 increased uterine wet weight (P < 0.05). RNAseq analysis revealed that E2 significantly altered expression of 1991 uterine genes (P < 0.05). SPI feeding had no effect on uterine weight and altered expression of far fewer genesmore » than E2 at 152 genes (P < 0.05). Overlap between E2 and SPI genes was limited to 67 genes. Functional annotation analysis indicated significant differences in uterine biological processes affected by E2 and SPI and little evidence for recruitment of estrogen receptor (ER)α to the promoters of ER-responsive genes after SPI feeding. The major E2 up-regulated uterine pathways were carcinogenesis and extracellular matrix organization, whereas SPI feeding up-regulated uterine peroxisome proliferator activated receptor (PPAR) signaling and fatty acid metabolism. The combination of E2 and SPI resulted in significant regulation of 504 fewer genes relative to E2 alone. The ability of E2 to induce uterine proliferation in response to the carcinogen dimethybenz(a)anthracene (DMBA) as measured by expression of PCNA and Ki67 mRNA was suppressed by feeding SPI (P < 0.05). These data suggest that SPI is a selective estrogen receptor modulator (SERM) interacting with a small sub-set of E2-regulated genes and is anti-estrogenic in the presence of endogenous estrogens. - Highlights: • Concerns exist regarding risk of uterine cancer from consumption of soy products. • These concerns are related to potential estrogenicity. • Estradiol and soy protein isolate effects on uterine gene expression were compared. • Soy acts as a selective estrogen receptor modulator not a weak estrogen. • Soy feeding blocked uterine proliferation after treatment with estradiol and DMBA.« less

Combinations of physiologic estrogens with xenoestrogens alter calcium and kinase responses, prolactin release, and membrane estrogen receptor trafficking in rat pituitary cells

PubMed Central

2010-01-01

Background Xenoestrogens such as alkylphenols and the structurally related plastic byproduct bisphenol A have recently been shown to act potently via nongenomic signaling pathways and the membrane version of estrogen receptor-α. Though the responses to these compounds are typically measured individually, they usually contaminate organisms that already have endogenous estrogens present. Therefore, we used quantitative medium-throughput screening assays to measure the effects of physiologic estrogens in combination with these xenoestrogens. Methods We studied the effects of low concentrations of endogenous estrogens (estradiol, estriol, and estrone) at 10 pM (representing pre-development levels), and 1 nM (representing higher cycle-dependent and pregnancy levels) in combinations with the same levels of xenoestrogens in GH3/B6/F10 pituitary cells. These levels of xenoestrogens represent extremely low contamination levels. We monitored calcium entry into cells using Fura-2 fluorescence imaging of single cells. Prolactin release was measured by radio-immunoassay. Extracellular-regulated kinase (1 and 2) phospho-activations and the levels of three estrogen receptors in the cell membrane (ERα, ERβ, and GPER) were measured using a quantitative plate immunoassay of fixed cells either permeabilized or nonpermeabilized (respectively). Results All xenoestrogens caused responses at these concentrations, and had disruptive effects on the actions of physiologic estrogens. Xenoestrogens reduced the % of cells that responded to estradiol via calcium channel opening. They also inhibited the activation (phosphorylation) of extracellular-regulated kinases at some concentrations. They either inhibited or enhanced rapid prolactin release, depending upon concentration. These latter two dose-responses were nonmonotonic, a characteristic of nongenomic estrogenic responses. Conclusions Responses mediated by endogenous estrogens representing different life stages are vulnerable to very low concentrations of these structurally related xenoestrogens. Because of their non-classical dose-responses, they must be studied in detail to pinpoint effective concentrations and the directions of response changes. PMID:20950447

Loss of ERβ expression as a common step in estrogen-dependent tumor progression

PubMed Central

Bardin, Allison; Boulle, Nathalie; Lazennec, Gwendal; Vignon, Françoise; Pujol, Pascal

2004-01-01

The characterization of estrogen receptor beta (ERβ) brought new insight into the mechanisms underlying estrogen signaling. Estrogen induction of cell proliferation is a crucial step in carcinogenesis of gynecologic target tissues and the mitogenic effects of estrogen in these tissues (e.g. breast, endometrium and ovary) are well documented both in vitro and in vivo. There is also an emerging body of evidence that colon and prostate cancer growth is influenced by estrogens. In all of these tissues, most studies have shown decreased ERβ expression in cancer as compared to benign tumors or normal tissues, whereas ERα expression persists. The loss of ERβ expression in cancer cells could reflect tumor cell dedifferentiation but may also represent a critical stage in estrogen-dependent tumor progression. Modulation of the expression of ERα target genes by ERβ, or ERβ specific gene induction could indicate that ERβ has a differential effect on proliferation as compared to ERα. ERβ may exert a protective effect and thus constitute a new target for hormone therapy, e.g. via ligand specific activation. The potential distinct roles of ERα and ERβ expression in carcinogenesis, as suggested by experimental and clinical data, are discussed in this review. PMID:15369453

17Beta-estradiol protects against oxidative stress-induced cell death through the glutathione/glutaredoxin-dependent redox regulation of Akt in myocardiac H9c2 cells.

PubMed

Urata, Yoshishige; Ihara, Yoshito; Murata, Hiroaki; Goto, Shinji; Koji, Takehiko; Yodoi, Junji; Inoue, Satoshi; Kondo, Takahito

2006-05-12

The GSH/glutaredoxin (GRX) system is involved in the redox regulation of certain enzyme activities, and this system protects cells from H2O2-induced apoptosis by regulating the redox state of Akt (Murata, H., Ihara, Y., Nakamura, H., Yodoi, J., Sumikawa, K., and Kondo, T. (2003) J. Biol. Chem. 278, 50226-50233). Estrogens, such as 17beta-estradiol (E2), play an important role in development, growth, and differentiation and appear to have protective effects on oxidative stress mediated by estrogen receptor alpha (ERalpha). However, the role of the ERbeta-mediated pathway in this cytoprotection and the involvement of E2 in the redox regulation are not well understood. In the present study, we demonstrated that E2 protected cardiac H9c2 cells, expressing ERbeta from H2O2-induced apoptosis concomitant with an increase in the activity of Akt. E2 induced the expression of glutaredoxin (GRX) as well as gamma-glutamylcysteine synthetase, a rate-limiting enzyme for the synthesis of GSH. Inhibitors for both gamma-glutamylcysteine synthetase and GRX and ICI182,780, a specific inhibitor of ERs, abolished the protective effect of E2 on cell survival as well as the activity of Akt, suggesting that ERbeta is involved in the cytoprotection and redox regulation by E2. Transcription of the GRX gene was enhanced by E2. The promoter activity of GRX was up-regulated by an ERbeta-dependent element. These results suggest that the GRX/GSH system is involved in the cytoprotective and genomic effects of E2 on the redox state of Akt, a pathway that is mediated, at least in part, by ERbeta. This mechanism may also play an antiapoptotic role in cancer cells during carcinogenesis or chemotherapy.

Determination of the Role of Estrogen Receptors and Estrogen Regulated Genes in B cell Autoreactivity. Addendum

DTIC Science & Technology

2012-07-01

Betty Diamond – DOD FINAL REPORT 9 Figure 3: (A) expression of estrogen receptors ERalpha( Esr1 ) and ERbeta (Esr2) in splenic B cells and (B)Urinary...16 OH-Estradiol metabolite in BALB/c and C57BL6 mice. Esr1 0 0.05 0.1 0.15 0.2 Transit. Mature Transit. Mature Transit. Mature Transit. mature P E2 P

Expression and subcellular localization of estrogen receptors α and β in human fetal brown adipose tissue.

PubMed

Velickovic, Ksenija; Cvoro, Aleksandra; Srdic, Biljana; Stokic, Edita; Markelic, Milica; Golic, Igor; Otasevic, Vesna; Stancic, Ana; Jankovic, Aleksandra; Vucetic, Milica; Buzadzic, Biljana; Korac, Bato; Korac, Aleksandra

2014-01-01

Brown adipose tissue (BAT) has the unique ability of generating heat due to the expression of mitochondrial uncoupling protein 1 (UCP1). A recent discovery regarding functional BAT in adult humans has increased interest in the molecular pathways of BAT development and functionality. An important role for estrogen in white adipose tissue was shown, but the possible role of estrogen in human fetal BAT (fBAT) is unclear. The objective of this study was to determine whether human fBAT expresses estrogen receptor α (ERα) and ERβ. In addition, we examined their localization as well as their correlation with crucial proteins involved in BAT differentiation, proliferation, mitochondriogenesis and thermogenesis including peroxisome proliferator-activated receptor γ (PPARγ), proliferating cell nuclear antigen (PCNA), PPARγ-coactivator-1α (PGC-1α), and UCP1. The fBAT was obtained from 4 human male fetuses aged 15, 17, 20, and 23 weeks gestation. ERα and ERβ expression was assessed using Western blotting, immunohistochemistry, and immunocytochemistry. Possible correlations with PPARγ, PCNA, PGC-1α, and UCP1 were examined by double immunofluorescence. Both ERα and ERβ were expressed in human fBAT, with ERα being dominant. Unlike ERβ, which was present only in mature brown adipocytes, we detected ERα in mature adipocytes, preadipocytes, mesenchymal and endothelial cells. In addition, double immunofluorescence supported the notion that differentiation in fBAT probably involves ERα. Immunocytochemical analysis revealed mitochondrial localization of both receptors. The expression of both ERα and ERβ in human fBAT suggests a role for estrogen in its development, primarily via ERα. In addition, our results indicate that fBAT mitochondria could be targeted by estrogens and pointed out the possible role of both ERs in mitochondriogenesis.

Steroid hormone receptors: long- and short-term integrators of the internal milieu and the external environment.

PubMed

Blaustein, J D

2012-07-01

Many of the influences of estrogens and progestins on the brain and behavior are mediated by estrogen receptors and progestin receptors, acting as transcriptional regulators. The homologous and heterologous regulation of the concentrations of these receptors by cognate hormones is well established. However, although they were discovered and characterized based on their binding to cognate hormone and their role in transcriptional regulation, steroid hormone receptors have a more complex role and serve many more functions than originally suspected. First, besides being regulated by steroid hormones, the intracellular concentrations of brain steroid hormone receptors are regulated by neurotransmitters, a pathway by which stimuli from the environment, including from conspecific animals, can modulate the concentration of particular steroid hormone receptors in subsets of cells. Further, besides being activated by cognate steroid hormones, the receptors can be activated by a variety of neurotransmitters and phosphorylation pathways, providing a route through which environmental stimulation can activate steroid-receptor-dependent functions in specific cells. In addition, the transcription factor, estrogen receptor-α, produced from the estrogen receptor-α gene, can be modified to be targeted to membranes, where it can signal via kinase pathways. Finally, developmental experiences, such as particular stressors during the pubertal period, can permanently remodel the brain's response to ovarian hormones, most likely by long-term changes in regulation of the receptors mediating those responses. In addition to their function in responding to cognate ligand, it is now more appropriate to think of steroid hormone receptors as integrators of a wide variety of signaling pathways. © Georg Thieme Verlag KG Stuttgart · New York.

Age differentially influences estrogen receptor-alpha (ERalpha) and estrogen receptor-beta (ERbeta) gene expression in specific regions of the rat brain.

PubMed

Wilson, Melinda E; Rosewell, Katherine L; Kashon, Michael L; Shughrue, Paul J; Merchenthaler, Istvan; Wise, Phyllis M

2002-03-31

Estradiol's ability to influence neurochemical events that are critical to female reproductive cyclicity and behavior decreases with age. We tested the hypothesis that decreases in estrogen receptor-alpha (ERalpha) and/or ERbeta mRNA explain the brain's declining responsiveness to estradiol. We assessed ERalpha and ERbeta mRNA levels in intact and ovariectomized estradiol-treated rats. ERbeta mRNA was detected in several brain regions and decreased by middle-age in the cerebral cortex and supraoptic nucleus of estradiol-treated rats. ERbeta mRNA levels exhibited a diurnal rhythm in the suprachiasmatic nucleus of young and middle-aged rats and this rhythm was blunted in old rats. We examined ERalpha mRNA in the periventricular preoptic, medial preoptic, ventromedial and arcuate nuclei, and it was decreased only in the periventricular preoptic nucleus of the old rats. In summary, the expression of ERalpha and ERbeta mRNAs is differentially modulated in the aging brain and changes are region specific.

A neuroendocrine predisposition for homosexuality in men.

PubMed

Dörner, G; Rohde, W; Stahl, F; Krell, L; Masius, W G

1975-01-01

In male rats, androgen deficiency during a critical hypothalamic organizational period was shown to give rise to a predominantly female-differentiated brain, homosexual behavior, and demonstration of a positive estrogen feedback effect. A positive estrogen feedback effect was also induced in intact homosexual men in contrast to intact heterosexual and bisexual men. Thus in 21 homosexual men an intravenous injection of 20 mg Presomen (Premarin) produced a significant decrease of serum LH levels followed by an increase above initial LH values. In 20 heterosexual and in five bisexual men, by contrast, intravenous estrogen administration, while producing a significant decrease of the serum LH level, was not followed by an increase above the initial LH values. Using a radioimmunoassay, plasma testosterone levels and 24-hr urinary excretions of unconjugated testosterone of adult homosexual men were found to be in the normal range as observed in heterosexual men. This finding suggests that homosexual men possess a predominantly female-differentiated brain which may be activated to homosexual behavior by normal or approximately normal androgen levels in adulthood.

Estrogen Receptor-Related Receptor α Mediates Up-Regulation of Aromatase Expression by Prostaglandin E2 in Prostate Stromal Cells

PubMed Central

Miao, Lin; Shi, Jiandang; Wang, Chun-Yu; Zhu, Yan; Du, Xiaoling; Jiao, Hongli; Mo, Zengnan; Klocker, Helmut; Lee, Chung; Zhang, Ju

2010-01-01

Estrogen receptor-related receptor α (ERRα) is an orphan member of the nuclear receptor superfamily of transcription factors. ERRα is highly expressed in the prostate, especially in prostate stromal cells. However, little is known about the regulation and function of ERRα, 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 ERRα, which, as a transcription factor, further mediates the regulatory effects of PGE2 on the expression of aromatase. ERRα 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 ERRα activity by chlordane (an antagonist of ERRα) or small interfering RNA knockdown of ERRα blocked the increase of expression and promoter activity of aromatase induced by PGE2. Overexpression of ERRα significantly increased aromatase expression and promoter activity, which were further augmented by PGE2. Chromatin immunoprecipitation assay demonstrated that ERRα directly bound to the aromatase promoter in vivo, and PGE2 enhanced the recruitment of ERRα and promoted transcriptional regulatory effects on aromatase expression in WPMY-1. 17β-Estradiol concentration in WPMY-1 medium was up-regulated by ERRα expression, and that was further increased by PGE2. Our results provided evidence that ERRα contributed to local estrogen production by up-regulating aromatase expression in response to PGE2 and provided further insights into the potential role of ERRα in estrogen-related prostatic diseases. PMID:20351196

Inhibition of lactation.

PubMed

Llewellyn-Jones, D

1975-01-01

The mechanism and hormonal regulation of lactation is explained and illustrated with a schematic representation. Circulating estrogen above a critical amount seems to be the inhibitory factor controlling lactation during pregnancy. Once delivery occurs, the level of estrogen falls, that of prolactin rises, and lactation begins. Nonsuckling can be used to inhibit lactation. Estrogens can also be used to inhibit lactation more quickly and with less pain. The reported association between estrogens and puerperal thromboembolism cannot be considered conclusive due to defects in the reporting studies. There is no reason not to use estrogens in lactation inhibition except for women over 35 who experienced a surgical delivery. Alternative therapy is available for these women. The recently-developed drug, brom-ergocryptine, may replace other methods of lactation inhibition.

BMI-1 Mediates Estrogen-Deficiency-Induced Bone Loss by Inhibiting Reactive Oxygen Species Accumulation and T Cell Activation.

PubMed

Li, Jinbo; Wang, Qian; Yang, Renlei; Zhang, Jiaqi; Li, Xing; Zhou, Xichao; Miao, Dengshun

2017-05-01

Previous studies have shown that estrogen regulates bone homeostasis through regulatory effects on oxidative stress. However, it is unclear how estrogen deficiency triggers reactive oxygen species (ROS) accumulation. Recent studies provide evidence that the B lymphoma Mo-MLV insertion region 1 (BMI-1) plays a critical role in protection against oxidative stress and that this gene is directly regulated by estrogen via estrogen receptor (ER) at the transcriptional level. In this study, ovariectomized mice were given drinking water with/without antioxidant N-acetyl-cysteine (NAC, 1 mg/mL) supplementation, and compared with each other and with sham mice. Results showed that ovariectomy resulted in bone loss with increased osteoclast surface, increased ROS levels, T cell activation, and increased TNF and RANKL levels in serum and in CD4 T cells; NAC supplementation largely prevented these alterations. BMI-1 expression levels were dramatically downregulated in CD4 T cells from ovariectomized mice. We supplemented drinking water to BMI-1-deficient mice with/without NAC and compared them with each other and with wild-type (WT) mice. We found that BMI-1 deficiency mimicked alterations observed in ovariectomy whereas NAC supplementation reversed all alterations induced by BMI-1 deficiency. Because T cells are critical in mediating ovariectomy-induced bone loss, we further assessed whether BMI-1 overexpression in lymphocytes can protect against estrogen deficiency-induced osteoclastogenesis and bone loss by inhibiting oxidative stress, T cell activation, and RANKL production. When WT and Eμ-BMI-1 transgenic mice with BMI-1 specifically overexpressed in lymphocytes were ovariectomized and compared with each other and with WT sham mice, we found that BMI-1 overexpression in lymphocytes clearly reversed all alterations induced by ovariectomy. Results from this study indicate that estrogen deficiency downregulates BMI-1 and subsequently increases ROS, T cell activation, and RANKL production in T cells, thus enhancing osteoclastogenesis and accelerating bone loss. This study clarifies a novel mechanism regulating estrogen deficiency-induced bone loss. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and Mineral Research.

Regulation of Baboon Fetal Ovarian Development by Placental Estrogen: Onset of Puberty Is Delayed in Offspring Deprived of Estrogen In Utero1

PubMed Central

Pepe, Gerald J.; Lynch, Terrie J.; Albrecht, Eugene D.

2013-01-01

ABSTRACT Using the baboon as a model for studies of human reproductive biology, we previously showed that placental estrogen regulates fetal ovarian follicle development. In this study, offspring of baboons untreated or treated in utero with the aromatase inhibitor letrozole (estradiol reduced >95%) or letrozole and estradiol were reared to adulthood to determine whether estrogen programming of the fetal ovary impacted puberty and reproduction in adulthood. All offspring exhibited normal growth and blood pressure/chemistries. Puberty onset in untreated baboons (43.2 ± 1.4 mo) was delayed (P < 0.01) in animals of letrozole-treated mothers (49.0 ± 1.2 mo) and normal in offspring of mothers treated with letrozole and estradiol (42.7 ± 0.8 mo). During the first 2 yr postmenarche, menstrual cycles in estrogen-suppressed animals (43.2 ± 1.3 days) were longer (P < 0.05) than in untreated baboons (38.3 ± 0.5 days) or those treated with letrozole and estrogen (39.6 ± 0.8 days). Moreover, in estrogen-suppressed offspring, serum levels of estradiol were lower and follicle-stimulating hormone greater (P < 0.05) in the follicular and luteal phases, and the elevation in luteal-phase progesterone extended (P < 0.02). Thus, puberty onset was delayed and menstrual cycles prolonged and associated with altered serum hormone levels in baboon offspring that developed in an intrauterine environment in which estradiol levels were suppressed. Because puberty and follicle development, as shown previously, were normal in baboons treated in utero with letrozole and estradiol, we propose that fetal ovarian development and timely onset of puberty in the primate is programmed by fetal exposure to placental estrogen. PMID:24132960

Regulation of baboon fetal ovarian development by placental estrogen: onset of puberty is delayed in offspring deprived of estrogen in utero.

PubMed

Pepe, Gerald J; Lynch, Terrie J; Albrecht, Eugene D

2013-12-01

Using the baboon as a model for studies of human reproductive biology, we previously showed that placental estrogen regulates fetal ovarian follicle development. In this study, offspring of baboons untreated or treated in utero with the aromatase inhibitor letrozole (estradiol reduced >95%) or letrozole and estradiol were reared to adulthood to determine whether estrogen programming of the fetal ovary impacted puberty and reproduction in adulthood. All offspring exhibited normal growth and blood pressure/chemistries. Puberty onset in untreated baboons (43.2 ± 1.4 mo) was delayed (P < 0.01) in animals of letrozole-treated mothers (49.0 ± 1.2 mo) and normal in offspring of mothers treated with letrozole and estradiol (42.7 ± 0.8 mo). During the first 2 yr postmenarche, menstrual cycles in estrogen-suppressed animals (43.2 ± 1.3 days) were longer (P < 0.05) than in untreated baboons (38.3 ± 0.5 days) or those treated with letrozole and estrogen (39.6 ± 0.8 days). Moreover, in estrogen-suppressed offspring, serum levels of estradiol were lower and follicle-stimulating hormone greater (P < 0.05) in the follicular and luteal phases, and the elevation in luteal-phase progesterone extended (P < 0.02). Thus, puberty onset was delayed and menstrual cycles prolonged and associated with altered serum hormone levels in baboon offspring that developed in an intrauterine environment in which estradiol levels were suppressed. Because puberty and follicle development, as shown previously, were normal in baboons treated in utero with letrozole and estradiol, we propose that fetal ovarian development and timely onset of puberty in the primate is programmed by fetal exposure to placental estrogen.

Estrogen receptor signaling in prostate cancer: Implications for carcinogenesis and tumor progression.

PubMed

Bonkhoff, Helmut

2018-01-01

The androgen receptor (AR) is the classical target for prostate cancer prevention and treatment, but more recently estrogens and their receptors have also been implicated in prostate cancer development and tumor progression. Recent experimental and clinical data were reviewed to elucidate pathogenetic mechanisms how estrogens and their receptors may affect prostate carcinogenesis and tumor progression. The estrogen receptor beta (ERβ) is the most prevalent ER in the human prostate, while the estrogen receptor alpha (ERα) is restricted to basal cells of the prostatic epithelium and stromal cells. In high grade prostatic intraepithelial neoplasia (HGPIN), the ERα is up-regulated and most likely mediates carcinogenic effects of estradiol as demonstrated in animal models. The partial loss of the ERβ in HGPIN indicates that the ERβ acts as a tumor suppressor. The tumor promoting function of the TMPRSS2-ERG fusion, a major driver of prostate carcinogenesis, is triggered by the ERα and repressed by the ERβ. The ERβ is generally retained in hormone naïve and metastatic prostate cancer, but is partially lost in castration resistant disease. The progressive emergence of the ERα and ERα-regulated genes (eg, progesterone receptor (PR), PS2, TMPRSS2-ERG fusion, and NEAT1) during prostate cancer progression and hormone refractory disease suggests that these tumors can bypass the AR by using estrogens and progestins for their growth. In addition, nongenomic estrogen signaling pathways mediated by orphan receptors (eg, GPR30 and ERRα) has also been implicated in prostate cancer progression. Increasing evidences demonstrate that local estrogen signaling mechanisms are required for prostate carcinogenesis and tumor progression. Despite the recent progress in this research topic, the translation of the current information into potential therapeutic applications remains highly challenging and clearly warrants further investigation. © 2017 Wiley Periodicals, Inc.

Caudal fourth ventricular administration of the AMPK activator 5-aminoimidazole-4-carboxamide-riboside regulates glucose and counterregulatory hormone profiles, dorsal vagal complex metabolosensory neuron function, and hypothalamic Fos expression.

PubMed

Ibrahim, Baher A; Tamrakar, Pratistha; Gujar, Amit D; Cherian, Ajeesh Koshy; Briski, Karen P

2013-09-01

This study investigated the hypothesis that estrogen controls hindbrain AMP-activated protein kinase (AMPK) activity and regulation of blood glucose, counterregulatory hormone secretion, and hypothalamic nerve cell transcriptional status. Dorsal vagal complex A2 noradrenergic neurons were laser microdissected from estradiol benzoate (E)- or oil (O)-implanted ovariectomized female rats after caudal fourth ventricular (CV4) delivery of the AMPK activator 5-aminoimidazole-4-carboxamide-riboside (AICAR), for Western blot analysis. E advanced AICAR-induced increases in A2 phospho-AMPK (pAMPK) expression and in blood glucose levels and was required for augmentation of Fos, estrogen receptor-α (ERα), monocarboxylate transporter-2, and glucose transporter-3 protein in A2 neurons and enhancement of corticosterone secretion by this treatment paradigm. CV4 AICAR also resulted in site-specific modifications in Fos immunolabeling of hypothalamic metabolic structures, including the paraventricular, ventromedial, and arcuate nuclei. The current studies demonstrate that estrogen regulates AMPK activation in caudal hindbrain A2 noradrenergic neurons during pharmacological replication of energy shortage in this area of the brain, and that this sensor is involved in neural regulation of glucostasis, in part, through control of corticosterone secretion. The data provide unique evidence that A2 neurons express both ERα and -β proteins and that AMPK upregulates cellular sensitivity to ERα-mediated signaling during simulated energy insufficiency. The results also imply that estrogen promotes glucose and lactate uptake by these cells under those conditions. Evidence for correlation between hindbrain AMPK and hypothalamic nerve cell genomic activation provides novel proof for functional connectivity between this hindbrain sensor and higher order metabolic brain loci while demonstrating a modulatory role for estrogen in this interaction. Copyright © 2013 Wiley Periodicals, Inc.

Acyl-coenzyme A oxidases 1 and 3 in brown trout (Salmo trutta f. fario): Can peroxisomal fatty acid β-oxidation be regulated by estrogen signaling?

PubMed

Madureira, Tânia Vieira; Castro, L Filipe C; Rocha, Eduardo

2016-02-01

Acyl-coenzyme A oxidases 1 (Acox1) and 3 (Acox3) are key enzymes in the regulation of lipid homeostasis. Endogenous and exogenous factors can disrupt their normal expression/activity. This study presents for the first time the isolation and characterization of Acox1 and Acox3 in brown trout (Salmo trutta f. fario). Additionally, as previous data point to the existence of a cross-talk between two nuclear receptors, namely peroxisome proliferator-activated receptors and estrogen receptors, it was here evaluated after in vitro exposures of trout hepatocytes the interference caused by ethynylestradiol in the mRNA levels of an inducible (by peroxisome proliferators) and a non-inducible oxidase. The isolated Acox1 and Acox3 show high levels of sequence conservation compared to those of other teleosts. Additionally, it was found that Acox1 has two alternative splicing isoforms, corresponding to 3I and 3II isoforms of exon 3 splicing variants. Both isoforms display tissue specificity, with Acox1-3II presenting a more ubiquitous expression in comparison with Acox1-3I. Acox3 was expressed in almost all brown trout tissues. According to real-time PCR data, the highest estrogenic stimulus was able to cause a down-regulation of Acox1 and an up-regulation of Acox3. So, for Acox1 we found a negative association between an estrogenic input and a directly activated PPARα target gene. In conclusion, changes in hormonal estrogenic stimulus may impact the mobilization of hepatic lipids to the gonads, with ultimate consequences in reproduction. Further studies using in vivo assays will be fundamental to clarify these issues.

Obesity, Insulin Resistance and Diabetes: Sex Differences and Role of Estrogen Receptors

PubMed Central

Meyer, Matthias R.; Clegg, Deborah J.; Prossnitz, Eric R.; Barton, Matthias

2010-01-01

Obesity increases the risk of coronary artery disease through insulin resistance, diabetes, arterial hypertension, and dyslipidemia. The prevalence of obesity has increased worldwide and is particularly high among middle-aged women and men. After menopause, women are at an increased risk to develop visceral obesity due to the loss of endogenous ovarian hormone production. Effects of estrogens are classically mediated by the two nuclear estrogen receptors (ERs) α and β. In addition, more recent research has shown that the intracellular transmembrane G protein-coupled estrogen receptor, GPER, originally designated as GPR30, also mediates some of the actions attributed to estrogens. Estrogen and its receptors are important regulators of body weight and insulin sensitivity not only in women, but also in men as demonstrated by ER mutations in rodents and humans. This article reviews the role of sex hormones and estrogen receptors in the context of obesity, insulin sensitivity and diabetes as well as the related clinical issues in females and males. PMID:21281456

Role of estrogens in anterior pituitary gland remodeling during the estrous cycle.

PubMed

Zárate, S; Zaldivar, V; Jaita, G; Magri, L; Radl, D; Pisera, D; Seilicovich, A

2010-01-01

In this review, we analyze the action of estrogens leading to the remodeling of the anterior pituitary gland, especially during the estrous cycle. Proliferation and death of anterior pituitary cells and especially lactotropes is regulated by estrogens, which act by sensitizing these cells to both mitotic and apoptotic stimuli such as TNF-alpha, FasL and dopamine. During the estrous cycle, the changing pattern of gonadal steroids is thought to modulate both cell proliferation and death in the anterior pituitary gland, estrogens being key players in cell turnover. The mechanisms involved in estrogen-modulated cell renewal in the anterior pituitary gland during the estrous cycle could include an increase in the expression of proapoptotic cytokines as well as the increase in the Bax/Bcl-2 ratio at proestrus, when estrogen levels are highest and a peak of apoptosis, in particular of lactotropes, is evident in this gland. Estrogens exert rapid antimitogenic and proapoptotic actions in the anterior pituitary through membrane-associated estrogen receptors, a mechanism that might also be involved in remodeling of this gland during the estrous cycle. Copyright (c) 2010 S. Karger AG, Basel.

Early onset of puberty and early ovarian failure in CYP7B1 knockout mice.

PubMed

Omoto, Yoko; Lathe, Richard; Warner, Margaret; Gustafsson, Jan-Ake

2005-02-22

CYP7B1 is the enzyme responsible for hydroxylation and termination of the estrogenic actions of the androgen metabolite, 5alpha-androstane-3beta, 17beta-diol (3betaAdiol). 3betaAdiol is estrogenic in ERalpha or ERbeta positive cells only if they do not express CYP7B1. In this study we show that female CYP7B1(-/-) mice experience early onset of growth of the uterus and mammary glands and commence estrus cycles 2 days earlier than their wild-type littermates. Adult mammary glands and uteri appear to be under continuous estrogenic stimulation. We conclude that, by cell-specific regulation of the estrogenicity of 3betaAdiol, CYP7B1 performs two major tasks: (i) it allows 3betaAdiol to have growth inhibitory effects through ERbeta and (ii) it permits estradiol-specific activation of estrogen receptors by protection of certain cells from the estrogenic effects of 3betaAdiol. When CYP7B1 is inactivated, 3betaAdiol activates estrogen receptors indiscriminately, and the overall effect is prolonged and inappropriate exposure to estrogen.

ERβ induces the differentiation of cultured osteoblasts by both Wnt/β-catenin signaling pathway and estrogen signaling pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin, Xinhua; Wang, Xiaoyuan; Hu, Xiongke

Although 17β-estradial (E2) is known to stimulate bone formation, the underlying mechanisms are not fully understood. Recent studies have implicated the Wnt/β-catenin pathway as a major signaling cascade in bone biology. The interactions between Wnt/β-catenin signaling pathway and estrogen signaling pathways have been reported in many tissues. In this study, E2 significantly increased the expression of β-catenin by inducing phosphorylations of GSK3β at serine 9. ERβ siRNAs were transfected into MC3T3-E1 cells and revealed that ERβ involved E2-induced osteoblasts proliferation and differentiation via Wnt/β-catenin signaling. The osteoblast differentiation genes (BGP, ALP and OPN) and proliferation related gene (cyclin D1) expressionmore » were significantly induced by E2-mediated ERβ. Furthermore immunofluorescence and immunoprecipitation analysis demonstrated that E2 induced the accumulation of β-catenin protein in the nucleus which leads to interaction with T-cell-specific transcription factor/lymphoid enhancer binding factor (TCF/LEF) transcription factors. Taken together, these findings suggest that E2 promotes osteoblastic proliferation and differentiation by inducing proliferation-related and differentiation-related gene expression via ERβ/GSK-3β-dependent Wnt/β-catenin signaling pathway. Our findings provide novel insights into the mechanisms of action of E2 in osteoblastogenesis. - Highlights: • 17β-estradial (E2) promotes GSK3-β phosphorylation. • E2 activates the Wnt/β-catenin signaling pathway. • The Wnt/β-catenin signaling pathway interacts with estrogen signaling pathways. • E2-mediated ER induced osteoblast differentiation and proliferation related genes expression.« less

PCBs as environmental estrogens: Turtle sex determination as a biomarker of environmental contamination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergeron, J.M.; Crews, D.; McLachlan, J.A.

1994-09-01

Polychlorinated biphenyls (PCBs) are widespread, low-level environmental pollutants associated with adverse health effects such as immune suppression and teratogenicity. There is increasing evidence that some PCB compounds are capable of disrupting reproductive and endocrine function in fish, birds, and mammals, including humans, particularly during development. Research on the mechanism through which these compounds act to alter reproductive function indicates estrogenic activity, whereby the compounds may be altering sexual differentiation. Here we demonstrate the estrogenic effect of some PCBs by reversing gonadal sex in a reptile species that exhibits temperature-dependent sex determination. 17 refs., 1 fig., 1 tab.

Identifying a Mechanism for Crosstalk Between the Estrogen and Glucocorticoid Receptors | Center for Cancer Research

Cancer.gov

Estrogen has long been known to play important roles in the development and progression of breast cancer. Its receptor (ER), a member of the steroid receptor family, binds to estrogen response elements (EREs) in DNA and regulates gene transcription. More recently, another steroid receptor family member, the glucocorticoid receptor (GR), has been implicated in breast cancer progression, and ER/GR status is an important predictor of breast cancer outcome.

Long non-coding RNA MIAT is estrogen-responsive and promotes estrogen-induced proliferation in ER-positive breast cancer cells.

PubMed

Li, Yuehua; Jiang, Baohong; Wu, Xiaoping; Huang, Qin; Chen, Wenqi; Zhu, Hongbo; Qu, Xiaofei; Xie, Liming; Ma, Xin; Huang, Guo

2018-05-21

Estrogen drives the development and progression of estrogen receptor (ER)-positive breast cancer. However, the detailed mechanism underlying ER-driven carcinogenesis remains unclear despite extensive studies. Previously reports indicated higher expression of long non-coding RNA (lncRNA) myocardial infarction associated transcript (MIAT) in ER-positive breast cancer tissues than in ER-negative tissues. However, the functional relevance of MIAT in ER-positive breast cancer tumorigenesis was poorly understood. Here, we investigated the role of lncRNA MIAT in ER-positive breast cancer cells. MIAT was over-expressed in ER-positive breast cancer tissues and ER-positive breast cancer cell line MCF-7. Activating estrogen signaling by diethylstilbestrol (DES) led to a dose- and time-dependent up-regulation of MIAT in MCF-7 cells that was dependent on ERα, as evidenced by ERα silencing and pharmacological inhibition using ER antagonist ICI 182780. Silencing MIAT decreased DES-induced MCF-7 cell proliferation while overexpressing MIAT increased MCF-7 cell proliferation. Further mechanistic study identified that MIAT was critical for G1 to S phase cell cycle transition. Taken together, these results suggest that lncRNA MIAT is an estrogen-inducible lncRNA and a key regulator in ER-positive breast cancer cell growth. MIAT could serve as a potential biomarker and promising therapeutic target for ER-positive breast cancer. Copyright © 2018. Published by Elsevier Inc.

Different effects of bisphenol-A on memory behavior and synaptic modification in intact and estrogen-deprived female mice.

PubMed

Xu, Xiaohong; Gu, Ting; Shen, Qiaoqiao

2015-03-01

Bisphenol-A (BPA) has the capability of interfering with the effects of estrogens on modulating brain function. The purpose of this study was to investigate the effects of BPA on memory and synaptic modification in the hippocampus of female mice under different levels of cycling estrogen. BPA exposure (40, 400 μg/kg/day) for 8 weeks did not affect spatial memory and passive avoidance task of gonadally intact mice but improved ovariectomy (Ovx)-induced memory impairment, whereas co-exposure of BPA with estradiol benzoate (EB) diminished the rescue effect of EB on memory behavior of Ovx mice. The results of morphometric measurement showed that BPA positively modified the synaptic interface structure and increased the synaptic density of CA1 pyramidal cell in the hippocampus of Ovx females, but inhibited the enhancement of EB on synaptic modification and synaptogenesis of Ovx mice. Furthermore, BPA up-regulated synaptic proteins synapsin I and PSD-95 and NMDA receptor NR2B but inhibited EB-induced increase in PSD-95 and NR2B in the hippocampus of Ovx mice. These results suggest that BPA interfered with normal hormonal regulation in synaptic plasticity and memory of female mice as a potent estrogen mimetic and as a disruptor of estrogen under various concentrations of cycling estrogen. © 2014 International Society for Neurochemistry.

Estradiol Is a Critical Mediator of Macrophage-Nerve Cross Talk in Peritoneal Endometriosis

PubMed Central

Greaves, Erin; Temp, Julia; Esnal-Zufiurre, Arantza; Mechsner, Sylvia; Horne, Andrew W.; Saunders, Philippa T.K.

2016-01-01

Endometriosis occurs in approximately 10% of women and is associated with persistent pelvic pain. It is defined by the presence of endometrial tissue (lesions) outside the uterus, most commonly on the peritoneum. Peripheral neuroinflammation, a process characterized by the infiltration of nerve fibers and macrophages into lesions, plays a pivotal role in endometriosis-associated pain. Our objective was to determine the role of estradiol (E2) in regulating the interaction between macrophages and nerves in peritoneal endometriosis. By using human tissues and a mouse model of endometriosis, we demonstrate that macrophages in lesions recovered from women and mice are immunopositive for estrogen receptor β, with up to 20% being estrogen receptor α positive. In mice, treatment with E2 increased the number of macrophages in lesions as well as concentrations of mRNAs encoded by Csf1, Nt3, and the tyrosine kinase neurotrophin receptor, TrkB. By using in vitro models, we determined that the treatment of rat dorsal root ganglia neurons with E2 increased mRNA concentrations of the chemokine C-C motif ligand 2 that stimulated migration of colony-stimulating factor 1–differentiated macrophages. Conversely, incubation of colony-stimulating factor 1 macrophages with E2 increased concentrations of brain-derived neurotrophic factor and neurotrophin 3, which stimulated neurite outgrowth from ganglia explants. In summary, we demonstrate a key role for E2 in stimulating macrophage-nerve interactions, providing novel evidence that endometriosis is an estrogen-dependent neuroinflammatory disorder. PMID:26073038

Estrogen, Angiogenesis, Immunity and Cell Metabolism: Solving the Puzzle.

PubMed

Trenti, Annalisa; Tedesco, Serena; Boscaro, Carlotta; Trevisi, Lucia; Bolego, Chiara; Cignarella, Andrea

2018-03-15

Estrogen plays an important role in the regulation of cardiovascular physiology and the immune system by inducing direct effects on multiple cell types including immune and vascular cells. Sex steroid hormones are implicated in cardiovascular protection, including endothelial healing in case of arterial injury and collateral vessel formation in ischemic tissue. Estrogen can exert potent modulation effects at all levels of the innate and adaptive immune systems. Their action is mediated by interaction with classical estrogen receptors (ERs), ERα and ERβ, as well as the more recently identified G-protein coupled receptor 30/G-protein estrogen receptor 1 (GPER1), via both genomic and non-genomic mechanisms. Emerging data from the literature suggest that estrogen deficiency in menopause is associated with an increased potential for an unresolved inflammatory status. In this review, we provide an overview through the puzzle pieces of how 17β-estradiol can influence the cardiovascular and immune systems.

Long-term effects of early life exposure to environmental estrogens on ovarian function: Role of epigenetics

PubMed Central

Cruz, Gonzalo; Foster, Warren; Paredes, Alfonso; Yi, Kun Don; Uzumcu, Mehmet

2014-01-01

Estrogens play an important role in development and function of the brain and reproductive tract. Accordingly, it is thought that developmental exposure to environmental estrogens can disrupt neural and reproductive tract development potentially resulting in long-term alterations in neurobehavior and reproductive function. Many chemicals have been shown to have estrogenic activity whereas others affect estrogen production and turnover resulting in disruption of estrogen signaling pathways. However, these mechanisms and the concentrations required to induce these effects cannot account for the myriad adverse effects of environmental toxicants on estrogen sensitive target tissues. Hence, alternative mechanisms are thought to underlie the adverse effects documented in experimental animal models and thus could be important to human health. In this review, the epigenetic regulation of gene expression is explored as a potential target of environmental toxicants including estrogenic chemicals. We suggest that toxicant-induced changes in epigenetic signatures are important mechanisms underlying disruption of ovarian follicular development. In addition, we discuss how exposure to environmental estrogens during early life can alter gene expression through effects on epigenetic control potentially leading to permanent changes in ovarian physiology. PMID:25040227

Estrogen Receptors Modulation of Anxiety-Like Behavior.

PubMed

Borrow, A P; Handa, R J

2017-01-01

Estrogens exert profound effects on the expression of anxiety in humans and rodents; however, the directionality of these effects varies considerably within both clinical and preclinical literature. It is believed that discrepancies regarding the nature of estrogens' effects on anxiety are attributable to the differential effects of specific estrogen receptor (ER) subtypes. In this chapter we will discuss the relative impact on anxiety and anxiety-like behavior of each of the three main ERs: ERα, which has a generally anxiogenic effect, ERβ, which has a generally anxiolytic effect, and the G-protein-coupled ER known as GPR30, which has been found to both increase and decrease anxiety-like behavior. In addition, we will describe the known mechanisms by which these receptor subtypes exert their influence on emotional responses, focusing on the hypothalamic-pituitary-adrenal axis and the oxytocinergic and serotonergic systems. The impact of estrogens on the expression of anxiety is likely the result of their combined effects on all of these neurobiological systems. © 2017 Elsevier Inc. All rights reserved.

Estradiol and progesterone regulate the expression of insulin-like growth factor-I receptor and insulin-like growth factor binding protein-2 in the hypothalamus of adult female rats.

PubMed

Cardona-Gómez, G P; Chowen, J A; Garcia-Segura, L M

2000-06-05

Gonadal hormones interact with insulin-like growthfactor-I (IGF-I) to regulate synaptic plasticity during the estrous cycle in the rat mediobasal hypothalamus. It has been proposed that tanycytes, specialized glial cells lining the ventral region of the third ventricle, may regulate the availability of IGF-I to hypothalamic neurons. IGF-I levels in tanycytes fluctuate during the estrous cycle. Furthermore, estrogen administration to ovariectomized rats increases IGF-I levels in tanycytes, while progesterone, injected simultaneously with estrogen, blocks the estrogen-induced increase of IGF-I levels in tanycytes. To test whether hormonal regulation of IGF-I receptor (IGF-IR) and IGF binding protein-2 (IGFBP-2) may be involved in the accumulation of IGF-I in tanycytes, we assessed the effect of ovarian hormones on the levels of these molecules in the mediobasal hypothalamus of adult female rats. Ovariectomized animals were treated with either oil, estrogen, progesterone, or estrogen and progesterone simultaneously and then killed 6 or 24 h later. Some neurons, some astrocytes, and many tanycytes in the mediobasal hypothalamus were found by confocal microscopy to be immunoreactive for IGF-IR. IGFBP-2 immunoreactivity was restricted almost exclusively to tanycytes and ependymal cells and was colocalized with IGF-IR immunoreactivity in tanycytes. By electron microscope immunocytochemistry using colloidal gold labeling, IGF-IR and IGFBP-2 immunoreactivities were observed in the microvilli of tanycytes in the lumen of the third ventricle. IGF-IR and IGFBP-2 immunoreactive levels on the apical surface of tanycytes were significantly decreased by the administration of progesterone, either alone or in the presence of estradiol. IGF-IR levels in the mediobasal hypothalamus, measured by Western blotting, were not significantly affected by the separate administration of estradiol or progesterone to ovariectomized rats. However, the simultaneous administration of both hormones resulted in a marked decrease in IGF-IR protein levels. Estradiol administration to ovariectomized rats increased IGFBP-2 immunoreactive levels in the hypothalamus. While progesterone did not significantly affect IGFBP-2 expression, the simultaneous injection of estradiol and progesterone resulted in a marked decrease in IGFBP-2 protein levels. The effect of estradiol on IGFBP-2 was observed both in protein and mRNA levels, suggesting a transcriptional regulation. However, the simultaneous administration of progesterone and estradiol had different effects on IGF-IR protein and IGF-IR mRNA levels, as well as on IGFBP-2 protein and IGFBP-2 mRNA levels, suggesting a postranscriptional action. These findings indicate that estradiol and progesterone regulate the expression of IGF-IR and IGFBP-2 in the mediobasal hypothalamus of adult female rats. Regulation of the hypothalamic IGF-I system by ovarian hormones may be physiologically relevant for neuroendocrine regulation and for synaptic plasticity during the estrous cycle. These results do not support the hypothesis that estrogen-induced accumulation of IGF-I by tanycytes is mediated by the hormonal regulation of IGF-IR. However, estrogen-induced up-regulation of IGFBP-2 and progesterone-induced down-regulation of IGF-IR and IGFBP-2 levels in the apical plasma membrane of tanycytes may be involved in the fluctuation of IGF-I levels in the mediobasal hypothalamus during the estrous cycle. Copyright 2000 John Wiley & Sons, Inc.

The safety of 17a-methyltestosterone administered in feed to larval Nile tilapia

USDA-ARS?s Scientific Manuscript database

Techniques developed to control sexual differentiation in fishes have typically involved androgen or estrogen (i.e., steroid) treatment, which directs sexual differentiation toward males or females. Treatment regimens have included immersion of larval fish in water containing a steroid, incorporati...

Estradiol targets T cell signaling pathways in human systemic lupus.

PubMed

Walters, Emily; Rider, Virginia; Abdou, Nabih I; Greenwell, Cindy; Svojanovsky, Stan; Smith, Peter; Kimler, Bruce F

2009-12-01

The major risk factor for developing systemic lupus erythematosus (SLE) is being female. The present study utilized gene profiles of activated T cells from females with SLE and healthy controls to identify signaling pathways uniquely regulated by estradiol that could contribute to SLE pathogenesis. Selected downstream pathway genes (+/- estradiol) were measured by real time polymerase chain amplification. Estradiol uniquely upregulated six pathways in SLE T cells that control T cell function including interferon-alpha signaling. Measurement of interferon-alpha pathway target gene expression revealed significant differences (p= 0.043) in DRIP150 (+/- estradiol) in SLE T cell samples while IFIT1 expression was bimodal and correlated moderately (r= 0.55) with disease activity. The results indicate that estradiol alters signaling pathways in activated SLE T cells that control T cell function. Differential expression of transcriptional coactivators could influence estrogen-dependent gene regulation in T cell signaling and contribute to SLE onset and disease pathogenesis.

Expression of the estrogen receptors and steroidogenic enzymes involved in estradiol formation in the monkey vagina.

PubMed

Bertin, Jonathan; Ouellet, Johanne; Dury, Alain Yves; Pelletier, Georges; Labrie, Fernand

2014-11-01

Estrogens are well recognized to have beneficial effects on vulvovaginal atrophy because of menopause. The distribution of estrogen receptors and enzymes responsible for estradiol (E2) formation within the vagina may provide insight into how dehydroepiandrosterone, a precursor of both estrogens and androgens, improves vulvovaginal atrophy. The purpose of the study was to determine where the steroidogenic enzymes responsible for E2 formation as well as estrogen receptors are localized in vaginal specimens collected from cynomolgus monkeys (Macaca fascicularis), the closest model to the human. HSD3B1, HSD17B1, HSD17B5, HSD17B12, aromatase (CYP19A1), estrogen receptor (ER)-α, and ER-β were measured or localized by quantitative real-time polymerase chain reaction, immunohistochemistry, and immunofluorescence. Estrogens were quantified by liquid chromatography/tandem mass spectrometry. All steroidogenic enzymes and estrogen receptors are localized mainly in the superficial layer of the stratified squamous epithelium, blood vessel walls, and muscle fibers of the vagina. Immunolabeling of HSD17B5 and HSD17B12 shows that these enzymes are uniformly distributed from the basal membrane to the superficial keratinized cells, whereas HSD3B1 and aromatase are particularly localized in the outer (external) portion of the epithelial layer. ER-α and ER-β are also distributed within the vaginal epithelium, with expression especially elevated at the basal membrane level. The enzymes responsible for E2 formation as well as ERs are expressed mainly in the superficial layer of the stratified epithelium as well as the muscle layer of the vagina. The present data provide morphologic and biochemical support for the role of local dehydroepiandrosterone transformation into estrogens in regulating epithelial cell maturation, pH, fluid secretion, smooth muscle activity, and blood flow regulation in the primate vagina. Copyright © 2014 Elsevier Inc. All rights reserved.

Estrogen Receptor (ER) Subtype Selectivity Identifies 8-Prenylapigenin as an ERβ Agonist from Glycyrrhiza inflata and Highlights the Importance of Chemical and Biological Authentication.

PubMed

Hajirahimkhan, Atieh; Mbachu, Obinna; Simmler, Charlotte; Ellis, Sarah G; Dong, Huali; Nikolic, Dejan; Lankin, David C; van Breemen, Richard B; Chen, Shao-Nong; Pauli, Guido F; Dietz, Birgit M; Bolton, Judy L

2018-04-27

Postmenopausal women are increasingly using botanicals for menopausal symptom relief due to the increased breast cancer risk associated with traditional estrogen therapy. The deleterious effects of estrogens are associated with estrogen receptor (ER)α-dependent proliferation, while ERβ activation could enhance safety by opposing ERα effects. Three medicinal licorice species, Glycyrrhiza glabra ( G. glabra), G. uralensis, and G. inflata, were studied for their differential estrogenic efficacy. The data showed higher estrogenic potency for G. inflata in an alkaline phosphatase induction assay in Ishikawa cells (ERα) and an estrogen responsive element (ERE)-luciferase assay in MDA-MB-231/β41 breast cancer cells (ERβ). Bioassay-guided fractionation of G. inflata led to the isolation of 8-prenylapigenin (3). Surprisingly, a commercial batch of 3 was devoid of estrogenic activity. Quality control by MS and qNMR revealed an incorrect compound, 4'- O-methylbroussochalcone B (10), illustrating the importance of both structural and purity verification prior to any biological investigations. Authentic and pure 3 displayed 14-fold preferential ERβ agonist activity. Quantitative analyses revealed that 3 was 33 times more concentrated in G. inflata compared to the other medicinal licorice extracts. These data suggest that standardization of G. inflata to 3 might enhance the safety and efficacy of G. inflata supplements used for postmenopausal women's health.

The Conundrum of Estrogen Receptor Oscillatory Activity in the Search for an Appropriate Hormone Replacement Therapy

PubMed Central

Della Torre, Sara; Biserni, Andrea; Rando, Gianpaolo; Monteleone, Giuseppina; Ciana, Paolo; Komm, Barry

2011-01-01

By the use of in vivo imaging, we investigated the dynamics of estrogen receptor (ER) activity in intact, ovariectomized, and hormone-replaced estrogen response element-luciferase reporter mice. The study revealed the existence of a long-paced, noncircadian oscillation of ER transcriptional activity. Among the ER-expressing organs, this oscillation was asynchronous and its amplitude and period were tissue dependent. Ovariectomy affected the amplitude but did not suppress ER oscillations, suggesting the presence of tissue endogenous oscillators. Long-term administration of raloxifene, bazedoxifene, combined estrogens alone or with basedoxifene to ovariectomized estrogen response element-luciferase mice showed that each treatment induced a distinct spatiotemporal profile of ER activity, demonstrating that the phasing of ER activity among tissues may be regulated by the chemical nature and the concentration of circulating estrogen. This points to the possibility of a hierarchical organization of the tissue-specific pacemakers. Conceivably, the rhythm of ER transcriptional activity translates locally into the activation of specific gene networks enabling ER to significantly change its physiological activity according to circulating estrogens. In reproductive and nonreproductive organs this hierarchical regulation may provide ER with the signaling plasticity necessary to drive the complex metabolic changes occurring at each female reproductive status. We propose that the tissue-specific oscillatory activity here described is an important component of ER signaling necessary for the full hormone action including the beneficial effects reported for nonreproductive organs. Thus, this mechanism needs to be taken in due consideration to develop novel, more efficacious, and safer hormone replacement therapies. PMID:21505049

[The function of ERα in male reproductive system].

PubMed

Dong, Yu-Hang; Wei, Jin-Hua; Li, Zhen

2014-12-01

Estrogen receptors (ERs), including two sub-types ERα and ERβ, belong to the steroid hormone superfamily of nuclear receptors. ERα distributes in the male reproductive system and plays a crucial role in the regulation of male reproduction through estrogen-dependent and -independent ways. In this article, we mainly reviewed the molecular structure, mode of action and location of ERα in the male reproductive system, and explored the mechanism of ERα in regulating the male reproductive system by analyzing different animal models of disrupted ERα.

GPER mediated estradiol reduces miR-148a to promote HLA-G expression in breast cancer.

PubMed

Tao, Sifeng; He, Haifei; Chen, Qiang; Yue, Wenjie

2014-08-15

Breast cancer is the most common malignant diseases in women. miR-148a plays an important role in regulation of cancer cell proliferation and cancer invasion and down-regulation of miR-148a has been reported in both estrogen receptor (ER) positive and triple-negative (TN) breast cancer. However, the regulation mechanism of miR-148a is unclear. The role of estrogen signaling, a signaling pathway is important in development and progression of breast cancer. Therefore, we speculated that E2 may regulate miR-148a through G-protein-coupled estrogen receptor-1 (GPER). To test our hypothesis, we checked the effects of E2 on miR-148a expression in ER positive breast cancer cell MCF-7 and TN cancer cell MDA-MB-231. Then we used GPER inhibitor G15 to investigate whether GPER is involved in regulation of E2 on miR-148a. Furthermore, we analyzed whether E2 affects the expression of HLA-G, which is a miR-148a target gene through GPER. The results showed that E2 induces the level of miR-148a in MCF-7 and MDA-MB-231 cells, GPER mediates the E2-induced increase in miR-148a expression in MCF-7 and MDA-MB-231 cells and E2-GPER regulates the expression of HLA-G by miR-148a. In conclusion, our findings offer important new insights into the ability of estrogenic GPER signaling to trigger HLA-G expression through inhibiting miR-148a that supports immune evasion in breast cancer. Copyright © 2014 Elsevier Inc. All rights reserved.

Estrogenic Endocrine Disrupting Chemicals Influencing NRF1 Regulated Gene Networks in the Development of Complex Human Brain Diseases

PubMed Central

Preciados, Mark; Yoo, Changwon; Roy, Deodutta

2016-01-01

During the development of an individual from a single cell to prenatal stages to adolescence to adulthood and through the complete life span, humans are exposed to countless environmental and stochastic factors, including estrogenic endocrine disrupting chemicals. Brain cells and neural circuits are likely to be influenced by estrogenic endocrine disruptors (EEDs) because they strongly dependent on estrogens. In this review, we discuss both environmental, epidemiological, and experimental evidence on brain health with exposure to oral contraceptives, hormonal therapy, and EEDs such as bisphenol-A (BPA), polychlorinated biphenyls (PCBs), phthalates, and metalloestrogens, such as, arsenic, cadmium, and manganese. Also we discuss the brain health effects associated from exposure to EEDs including the promotion of neurodegeneration, protection against neurodegeneration, and involvement in various neurological deficits; changes in rearing behavior, locomotion, anxiety, learning difficulties, memory issues, and neuronal abnormalities. The effects of EEDs on the brain are varied during the entire life span and far-reaching with many different mechanisms. To understand endocrine disrupting chemicals mechanisms, we use bioinformatics, molecular, and epidemiologic approaches. Through those approaches, we learn how the effects of EEDs on the brain go beyond known mechanism to disrupt the circulatory and neural estrogen function and estrogen-mediated signaling. Effects on EEDs-modified estrogen and nuclear respiratory factor 1 (NRF1) signaling genes with exposure to natural estrogen, pharmacological estrogen-ethinyl estradiol, PCBs, phthalates, BPA, and metalloestrogens are presented here. Bioinformatics analysis of gene-EEDs interactions and brain disease associations identified hundreds of genes that were altered by exposure to estrogen, phthalate, PCBs, BPA or metalloestrogens. Many genes modified by EEDs are common targets of both 17 β-estradiol (E2) and NRF1. Some of these genes are involved with brain diseases, such as Alzheimer’s Disease (AD), Parkinson’s Disease, Huntington’s Disease, Amyotrophic Lateral Sclerosis, Autism Spectrum Disorder, and Brain Neoplasms. For example, the search of enriched pathways showed that top ten E2 interacting genes in AD—APOE, APP, ATP5A1, CALM1, CASP3, GSK3B, IL1B, MAPT, PSEN2 and TNF—underlie the enrichment of the Kyoto Encyclopedia of Genes and Genomes (KEGG) AD pathway. With AD, the six E2-responsive genes are NRF1 target genes: APBB2, DPYSL2, EIF2S1, ENO1, MAPT, and PAXIP1. These genes are also responsive to the following EEDs: ethinyl estradiol (APBB2, DPYSL2, EIF2S1, ENO1, MAPT, and PAXIP1), BPA (APBB2, EIF2S1, ENO1, MAPT, and PAXIP1), dibutyl phthalate (DPYSL2, EIF2S1, and ENO1), diethylhexyl phthalate (DPYSL2 and MAPT). To validate findings from Comparative Toxicogenomics Database (CTD) curated data, we used Bayesian network (BN) analysis on microarray data of AD patients. We observed that both gender and NRF1 were associated with AD. The female NRF1 gene network is completely different from male human AD patients. AD-associated NRF1 target genes—APLP1, APP, GRIN1, GRIN2B, MAPT, PSEN2, PEN2, and IDE—are also regulated by E2. NRF1 regulates targets genes with diverse functions, including cell growth, apoptosis/autophagy, mitochondrial biogenesis, genomic instability, neurogenesis, neuroplasticity, synaptogenesis, and senescence. By activating or repressing the genes involved in cell proliferation, growth suppression, DNA damage/repair, apoptosis/autophagy, angiogenesis, estrogen signaling, neurogenesis, synaptogenesis, and senescence, and inducing a wide range of DNA damage, genomic instability and DNA methylation and transcriptional repression, NRF1 may act as a major regulator of EEDs-induced brain health deficits. In summary, estrogenic endocrine disrupting chemicals-modified genes in brain health deficits are part of both estrogen and NRF1 signaling pathways. Our findings suggest that in addition to estrogen signaling, EEDs influencing NRF1 regulated communities of genes across genomic and epigenomic multiple networks may contribute in the development of complex chronic human brain health disorders. PMID:27983596

Mucin gene expression is not regulated by estrogen and/or progesterone in the ocular surface epithelia of mice.

PubMed

Lange, Christine; Fernandez, Jolene; Shim, David; Spurr-Michaud, Sandra; Tisdale, Ann; Gipson, Ilene K

2003-07-01

Dry eye syndrome is prevalent in post-menopausal women, and post-menopausal women secrete less mucus in their reproductive tracts. Using a mouse model, the purpose of this study was to determine if estrogen and/or progesterone regulates Muc4 and Muc5AC gene expression in the ocular surface epithelia, as the hormones do in reproductive tract epithelia. Adult C57BL/6 mice were ovariectomized, and 19 days later, pellets containing estrogen, progesterone, or a combination were inserted subcutaneously. Ocular surface and reproductive tract tissues were harvested following seven days of hormone treatment. A control group consisted of ovariectomized mice that received no hormone treatment. Real-time reverse transcription-polymerase chain reaction was used to determine the tissue expression levels of mucin mRNA of each treatment group relative to the control. Muc4 mRNA expression levels were determined for the reproductive tract, and both Muc4 and Muc5AC expression levels were determined for the ocular surface epithelia. Muc4 and Muc5AC gene expression in ocular surface and Muc4 in reproductive tract epithelia was demonstrated by In Situ hybridization, and Muc4 and Muc5AC protein was demonstrated in the epithelia of animals in the experimental groups. The mRNA expression levels of Muc4 and Muc5AC and the immunofluorescence localization pattern in the ocular surface epithelia were not significantly different in any hormone treatment group when compared to the control ovariectomized group. By comparison, mice that were administered estrogen had a significant increase of Muc4 mRNA in the reproductive tract epithelia, progesterone given in combination with estrogen antagonized the upregulatory effects of estrogen in the reproductive tract, and the amount of Muc4 mRNA in the reproductive tract of progesterone-treated animals was not different from ovariectomized controls. Immunofluorescence localization of Muc4 in the reproductive tract epithelia of the experimental groups correlated to message levels, with lack of Muc4 protein detected in the control and progesterone groups. In comparison to reproductive tract epithelia, Muc4 and Muc5AC are not hormonally regulated by estrogen or progesterone in the ocular surface epithelia of mice. These data demonstrate that regulation of epithelial mucin genes is tissue specific.

Estrogen Receptor Alpha (ESR1)-Dependent Regulation of the Mouse Oviductal Transcriptome.

PubMed

Cerny, Katheryn L; Ribeiro, Rosanne A C; Jeoung, Myoungkun; Ko, CheMyong; Bridges, Phillip J

2016-01-01

Estrogen receptor-α (ESR1) is an important transcriptional regulator in the mammalian oviduct, however ESR1-dependent regulation of the transcriptome of this organ is not well defined, especially at the genomic level. The objective of this study was therefore to investigate estradiol- and ESR1-dependent regulation of the transcriptome of the oviduct using transgenic mice, both with (ESR1KO) and without (wild-type, WT) a global deletion of ESR1. Oviducts were collected from ESR1KO and WT littermates at 23 days of age, or ESR1KO and WT mice were treated with 5 IU PMSG to stimulate follicular development and the production of ovarian estradiol, and the oviducts collected 48 h later. RNA extracted from whole oviducts was hybridized to Affymetrix Genechip Mouse Genome 430-2.0 arrays (n = 3 arrays per genotype and treatment) or reverse transcribed to cDNA for analysis of the expression of selected mRNAs by real-time PCR. Following microarray analysis, a statistical two-way ANOVA and pairwise comparison (LSD test) revealed 2428 differentially expressed transcripts (DEG's, P < 0.01). Genotype affected the expression of 2215 genes, treatment (PMSG) affected the expression of 465 genes, and genotype x treatment affected the expression of 438 genes. With the goal of determining estradiol/ESR1-regulated function, gene ontology (GO) and bioinformatic pathway analyses were performed on DEG's in the oviducts of PMSG-treated ESR1KO versus PMSG-treated WT mice. Significantly enriched GO molecular function categories included binding and catalytic activity. Significantly enriched GO cellular component categories indicated the extracellular region. Significantly enriched GO biological process categories involved a single organism, modulation of a measurable attribute and developmental processes. Bioinformatic analysis revealed ESR1-regulation of the immune response within the oviduct as the primary canonical pathway. In summary, a transcriptomal profile of estradiol- and ESR1-regulated gene expression and related bioinformatic analysis is presented to increase our understanding of how estradiol/ESR1 affects function of the oviduct, and to identify genes that may be proven as important regulators of fertility in the future.

Mangiferin positively regulates osteoblast differentiation and suppresses osteoclast differentiation

PubMed Central

Sekiguchi, Yuusuke; Mano, Hiroshi; Nakatani, Sachie; Shimizu, Jun; Kataoka, Aya; Ogura, Kana; Kimira, Yoshifumi; Ebata, Midori; Wada, Masahiro

2017-01-01

Mangiferin is a polyphenolic compound present in Salacia reticulata. It has been reported to reduce bone destruction and inhibit osteoclastic differentiation. This study aimed to determine whether mangiferin directly affects osteoblast and osteoclast proliferation and differentiation, and gene expression in MC3T3-E1 osteoblastic cells and osteoclast-like cells derived from primary mouse bone marrow macrophage cells. Mangiferin induced significantly greater WST-1 activity, indicating increased cell proliferation. Mangiferin induced significantly increased alkaline phosphatase staining, indicating greater cell differentiation. Reverse transcription-polymerase chain reaction (RT-PCR) demonstrated that mangiferin significantly increased the mRNA level of runt-related transcription factor 2 (RunX2), but did not affect RunX1 mRNA expression. Mangiferin significantly reduced the formation of tartrate-resistant acid phosphatase-positive multinuclear cells. RT-PCR demonstrated that mangiferin significantly increased the mRNA level of estrogen receptor β (ERβ), but did not affect the expression of other osteoclast-associated genes. Mangiferin may inhibit osteoclastic bone resorption by suppressing differentiation of osteoclasts and promoting expression of ERβ mRNA in mouse bone marrow macrophage cells. It also has potential to promote osteoblastic bone formation by promoting cell proliferation and inducing cell differentiation in preosteoblast MC3T3-E1 cells via RunX2. Mangiferin may therefore be useful in improving bone disease outcomes. PMID:28627701

Mangiferin positively regulates osteoblast differentiation and suppresses osteoclast differentiation.

PubMed

Sekiguchi, Yuusuke; Mano, Hiroshi; Nakatani, Sachie; Shimizu, Jun; Kataoka, Aya; Ogura, Kana; Kimira, Yoshifumi; Ebata, Midori; Wada, Masahiro

2017-08-01

Mangiferin is a polyphenolic compound present in Salacia reticulata. It has been reported to reduce bone destruction and inhibit osteoclastic differentiation. This study aimed to determine whether mangiferin directly affects osteoblast and osteoclast proliferation and differentiation, and gene expression in MC3T3‑E1 osteoblastic cells and osteoclast‑like cells derived from primary mouse bone marrow macrophage cells. Mangiferin induced significantly greater WST‑1 activity, indicating increased cell proliferation. Mangiferin induced significantly increased alkaline phosphatase staining, indicating greater cell differentiation. Reverse transcription‑polymerase chain reaction (RT‑PCR) demonstrated that mangiferin significantly increased the mRNA level of runt‑related transcription factor 2 (RunX2), but did not affect RunX1 mRNA expression. Mangiferin significantly reduced the formation of tartrate‑resistant acid phosphatase‑positive multinuclear cells. RT‑PCR demonstrated that mangiferin significantly increased the mRNA level of estrogen receptor β (ERβ), but did not affect the expression of other osteoclast‑associated genes. Mangiferin may inhibit osteoclastic bone resorption by suppressing differentiation of osteoclasts and promoting expression of ERβ mRNA in mouse bone marrow macrophage cells. It also has potential to promote osteoblastic bone formation by promoting cell proliferation and inducing cell differentiation in preosteoblast MC3T3‑E1 cells via RunX2. Mangiferin may therefore be useful in improving bone disease outcomes.

Estrogen receptor alpha phosphorylation and its functional impact in human breast cancer.

PubMed

Anbalagan, Muralidharan; Rowan, Brian G

2015-12-15

Estrogen receptor α (ERα) is a member of the nuclear receptor superfamily of transcription factors that regulates cell proliferation, differentiation and homeostasis in various tissues. Sustained exposure to estrogen/estradiol (E2) increases the risk of breast, endometrial and ovarian cancers. ERα function is also regulated by phosphorylation through various kinase signaling pathways that will impact various ERα functions including chromatin interaction, coregulator recruitment and gene expression, as well impact breast tumor growth/morphology and breast cancer patient response to endocrine therapy. However, many of the previously characterized ERα phosphorylation sites do not fully explain the impact of receptor phosphorylation on ERα function. This review discusses work from our laboratory toward understanding a role of ERα site-specific phosphorylation in ERα function and breast cancer. The key findings discussed in this review are: (1) the effect of site specific ERα phosphorylation on temporal recruitment of ERα and unique coactivator complexes to specific genes; (2) the impact of stable disruption of ERα S118 and S167 phosphorylation in breast cancer cells on eliciting unique gene expression profiles that culminate in significant effects on breast cancer growth/morphology/migration/invasion; (3) the Src kinase signaling pathway that impacts ERα phosphorylation to alter ERα function; and (4) circadian disruption by light exposure at night leading to elevated ERK1/2 and Src kinase and phosphorylation of ERα, concomitant with tamoxifen resistance in breast tumor models. Results from these studies demonstrate that even changes to single ERα phosphorylation sites can have a profound impact on ERα function in breast cancer. Future work will extend beyond single site phosphorylation analysis toward identification of specific patterns/profiles of ERα phosphorylation under different physiological/pharmacological conditions to understand how common phosphorylation profiles in breast cancer program specific physiological endpoints such as growth, apoptosis, migration/invasion, and endocrine therapy response. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Cdx2 Polymorphism Affects the Activities of Vitamin D Receptor in Human Breast Cancer Cell Lines and Human Breast Carcinomas

PubMed Central

Di Benedetto, Anna; Korita, Etleva; Goeman, Frauke; Sacconi, Andrea; Biagioni, Francesca; Blandino, Giovanni; Strano, Sabrina; Muti, Paola; Mottolese, Marcella; Falvo, Elisabetta

2015-01-01

Vitamin D plays a role in cancer development and acts through the vitamin D receptor (VDR). It regulates the action of hormone responsive genes and is involved in cell cycle regulation, differentiation and apoptosis. VDR is a critical component of the vitamin D pathway and different common single nucleotide polymorphisms have been identified. Cdx2 VDR polymorphism can play an important role in breast cancer, modulating the activity of VDR. The objective of this study is to assess the relationship between the Cdx2 VDR polymorphism and the activities of VDR in human breast cancer cell lines and carcinomas breast patients. Cdx2 VDR polymorphism and antiproliferative effects of vitamin D treatment were investigated in a panel of estrogen receptor-positive (MCF7 and T-47D) and estrogen receptor-negative (MDA-MB-231, SUM 159PT, SK-BR-3, BT549, MDA-MB-468, HCC1143, BT20 and HCC1954) human breast cancer cell lines. Furthermore, the potential relationship among Cdx2 VDR polymorphism and a number of biomarkers used in clinical management of breast cancer was assessed in an ad hoc set of breast cancer cases. Vitamin D treatment efficacy was found to be strongly dependent on the Cdx2 VDR status in ER-negative breast cancer cell lines tested. In our series of breast cancer cases, the results indicated that patients with variant homozygote AA were associated with bio-pathological characteristics typical of more aggressive tumours, such as ER negative, HER2 positive and G3. Our results may suggest a potential effect of Cdx2 VDR polymorphism on the efficacy of vitamin D treatment in aggressive breast cancer cells (estrogen receptor negative). These results suggest that Cdx2 polymorphism may be a potential biomarker for vitamin D treatment in breast cancer, independently of the VDR receptor expression. PMID:25849303

Visualizing estrogen receptor-a-expressing neurons using a new ERa-ZsGreen reporter mouse line

USDA-ARS?s Scientific Manuscript database

A variety of biological functions of estrogens, including regulation of energy metabolism, are mediated by neurons expressingestrogen receptor-a (ERa) in the brain. However, complex intracellular processes in these ERa-expressing neurons are difficult to unravel, due to the lack of strategy to visua...

The use of a whole animal biophotonic model as a screen for the angiogenic potential of estrogenic compounds

USDA-ARS?s Scientific Manuscript database

Vascular endothelial growth factor (VEGF) is essential for normal vascular growth and development during wound repair. VEGF is estrogen responsive and capable of regulating its own receptor, vascular endothelial growth factor receptor-2 (VEGFR-2). Several agricultural pesticides (e.g., methoxychlor)...

WNT4 is a key regulator of normal postnatal uterine development and progesterone signaling during embryo implantation and decidualization in the mouse

PubMed Central

Franco, Heather L.; Dai, Daisy; Lee, Kevin Y.; Rubel, Cory A.; Roop, Dennis; Boerboom, Derek; Jeong, Jae-Wook; Lydon, John P.; Bagchi, Indrani C.; Bagchi, Milan K.; DeMayo, Francesco J.

2011-01-01

WNT4, a member of the Wnt family of ligands, is critical for the development of the female reproductive tract. Analysis of Wnt4 expression in the adult uterus during pregnancy indicates that it may play a role in the regulation of endometrial stromal cell proliferation, survival, and differentiation, which is required to support the developing embryo. To investigate the role of Wnt4 in adult uterine physiology, conditional ablation of Wnt4 using the PRcre mouse model was accomplished. Ablation of Wnt4 rendered female mice subfertile due to a defect in embryo implantation and subsequent defects in endometrial stromal cell survival, differentiation, and responsiveness to progesterone signaling. In addition to altered stromal cell function, the uteri of PRcre/+Wnt4f/f (Wnt4d/d) mice displayed altered epithelial differentiation characterized by a reduction in the number of uterine glands and the emergence of a p63-positive basal cell layer beneath the columnar luminal epithelial cells. The altered epithelial cell phenotype was further escalated by chronic estrogen treatment, which caused squamous cell metaplasia of the uterine epithelium in the Wnt4d/d mice. Thus, WNT4 is a critical regulator not only of proper postnatal uterine development, but also embryo implantation and decidualization.—Franco, H. L., Dai, D., Lee, K. Y., Rubel, C. S., Roop, D., Boerboom, D., Jeong, J.-W., Lydon, J.-P., Bagchi, I. C., Bagchi, M. K., DeMayo, F. J. WNT4 is a key regulator of normal postnatal uterine development and progesterone signaling during embryo implantation and decidualization in the mouse. PMID:21163860

Combinations of Physiologic Estrogens with Xenoestrogens Alter ERK Phosphorylation Profiles in Rat Pituitary Cells

PubMed Central

Jeng, Yow-Jiun; Watson, Cheryl S.

2011-01-01

Background Estrogens are potent nongenomic phospho-activators of extracellular-signal–regulated kinases (ERKs). A major concern about the toxicity of xenoestrogens (XEs) is potential alteration of responses to physiologic estrogens when XEs are present simultaneously. Objectives We examined estrogen-induced ERK activation, comparing the abilities of structurally related XEs (alkylphenols and bisphenol A) to alter ERK responses induced by physiologic concentrations (1 nM) of estradiol (E2), estrone (E1), and estriol (E3). Methods We quantified hormone/mimetic-induced ERK phosphorylations in the GH3/B6/F10 rat pituitary cell line using a plate immunoassay, comparing effects with those on cell proliferation and by estrogen receptor subtype-selective ligands. Results Alone, these structurally related XEs activate ERKs in an oscillating temporal pattern similar (but not identical) to that with physiologic estrogens. The potency of all estrogens was similar (active between femtomolar and nanomolar concentrations). XEs potently disrupted physiologic estrogen signaling at low, environmentally relevant concentrations. Generally, XEs potentiated (at the lowest, subpicomolar concentrations) and attenuated (at the highest, picomolar to 100 nM concentrations) the actions of the physiologic estrogens. Some XEs showed pronounced nonmonotonic responses/inhibitions. The phosphorylated ERK and proliferative responses to receptor-selective ligands were only partially correlated. Conclusions XEs are both imperfect potent estrogens and endocrine disruptors; the more efficacious an XE, the more it disrupts actions of physiologic estrogens. This ability to disrupt physiologic estrogen signaling suggests that XEs may disturb normal functioning at life stages where actions of particular estrogens are important (e.g., development, reproductive cycling, pregnancy, menopause). PMID:20870566

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

Role of cocaine- and amphetamine-regulated transcript in estradiol-mediated neuroprotection

NASA Astrophysics Data System (ADS)

Xu, Yun; Zhang, Wenri; Klaus, Judith; Young, Jennifer; Koerner, Ines; Sheldahl, Laird C.; Hurn, Patricia D.; Martínez-Murillo, Francisco; Alkayed, Nabil J.

2006-09-01

Estrogen reduces brain injury after experimental cerebral ischemia in part through a genomic mechanism of action. Using DNA microarrays, we analyzed the genomic response of the brain to estradiol, and we identified a transcript, cocaine- and amphetamine-regulated transcript (CART), that is highly induced in the cerebral cortex by estradiol under ischemic conditions. Using in vitro and in vivo models of neural injury, we confirmed and characterized CART mRNA and protein up-regulation by estradiol in surviving neurons, and we demonstrated that i.v. administration of a rat CART peptide is protective against ischemic brain injury in vivo. We further demonstrated binding of cAMP response element (CRE)-binding protein to a CART promoter CRE site in ischemic brain and rapid activation by CART of ERK in primary cultured cortical neurons. The findings suggest that CART is an important player in estrogen-mediated neuroprotection and a potential therapeutic agent for stroke and other neurodegenerative diseases. ischemia | stroke | estrogen

A concise review of testosterone and bone health

PubMed Central

Mohamad, Nur-Vaizura; Soelaiman, Ima-Nirwana; Chin, Kok-Yong

2016-01-01

Osteoporosis is a condition causing significant morbidity and mortality in the elderly population worldwide. Age-related testosterone deficiency is the most important factor of bone loss in elderly men. Androgen can influence bone health by binding to androgen receptors directly or to estrogen receptors (ERs) indirectly via aromatization to estrogen. This review summarized the direct and indirect effects of androgens on bone derived from in vitro, in vivo, and human studies. Cellular studies showed that androgen stimulated the proliferation of preosteoblasts and differentiation of osteoblasts. The converted estrogen suppressed osteoclast formation and resorption activity by blocking the receptor activator of nuclear factor k-B ligand pathway. In animal studies, activation of androgen and ERα, but not ERβ, was shown to be important in acquisition and maintenance of bone mass. Human epidemiological studies demonstrated a significant relationship between estrogen and testosterone in bone mineral density and fracture risk, but the relative significance between the two remained debatable. Human experimental studies showed that estrogen was needed in suppressing bone resorption, but both androgen and estrogen were indispensable for bone formation. As a conclusion, maintaining optimal level of androgen is essential in preventing osteoporosis and its complications in elderly men. PMID:27703340

Shikonin, an ingredient of Lithospermum erythrorhizon, down-regulates the expression of steroid sulfatase genes in breast cancer cells.

PubMed

Zhang, Yi; Qian, Rui-Qin; Li, Ping-Ping

2009-10-18

Steroid sulfatase (STS) has an important role in regulating the biosynthesis of estrogen within breast tumors. We aimed to investigate whether shikonin, an ingredient of Lithospermum erythrorhizon, could modulate STS expression in breast cancer cells. By MTT assay, shikonin inhibited the cell proliferation of breast cancer cells MCF-7 and SK-BR-3. Moreover, by semi-quantitative/quantitative reverse transcription polymerase chain reaction and dual-luciferase reporter based bioluminescent measurements, the mRNA and enzymatic activity levels of STS were decreased after shikonin treatment. Concluding, shikonin could act as a selective estrogen enzyme modulator by down-regulating the STS expression.

Low doses of bisphenol A promote human seminoma cell proliferation by activating PKA and PKG via a membrane G-protein-coupled estrogen receptor.

PubMed

Bouskine, Adil; Nebout, Marielle; Brücker-Davis, Françoise; Benahmed, Mohamed; Fenichel, Patrick

2009-07-01

Fetal exposure to environmental estrogens may contribute to hypofertility and/or to testicular germ cell cancer. However, many of these xenoestrogens have only a weak affinity for the classical estrogen receptors (ERs,) which is 1,000-fold less potent than the affinity of 17beta-estradiol (E(2)). Thus, several mechanisms have been suggested to explain how they could affect male germ cell proliferation at low environmental relevant concentrations. In this study we aimed to explore the possible promoting effect of bisphenol A (BPA) on human testicular seminoma cells. BPA is a well-recognized estrogenic endocrine disruptor used as a monomer to manufacture poly carbonate plastic and released from resin-lined food or beverage cans or from dental sealants. BPA at very low concentrations (10(-9) to 10(-12) M) similar to those found in human fluids stimulated JKT-1 cell proliferation in vitro. BPA activated both cAMP-dependent protein kinase and cGMP-dependent protein kinase pathways and triggered a rapid (15 min) phosphorylation of the transcription factor cAMP response-element-binding protein (CREB) and the cell cycle regulator retinoblastoma protein (Rb). This nongenomic activation did not involve classical ERs because it could not be reversed by ICI 182780 (an ER antagonist) or reproduced either by E(2) or by diethylstilbestrol (a potent synthetic estrogen), which instead triggered a suppressive effect. This activation was reproduced only by E(2) coupled to bovine serum albumin (BSA), which is unable to enter the cell. As with E(2)-BSA, BPA promoted JKT-1 cell proliferation through a G-protein-coupled nonclassical membrane ER (GPCR) involving a Galpha(s) and a Galpha(i)/Galpha(q) subunit, as shown by the reversible effect observed by the corresponding inhibitors NF449 and pertussis toxin. This GPCR-mediated nongenomic action represents--in addition to the classical ER-mediated effect--a new basis for evaluating xenoestrogens such as BPA that, at low doses and with a high affinity for this GPCR, could interfere with the developmental programming of fetal germ cell proliferation and/or differentiation when they cross the placenta.

Early onset of puberty and early ovarian failure in CYP7B1 knockout mice

PubMed Central

Omoto, Yoko; Lathe, Richard; Warner, Margaret; Gustafsson, Jan-Åke

2005-01-01

CYP7B1 is the enzyme responsible for hydroxylation and termination of the estrogenic actions of the androgen metabolite, 5α-androstane-3β, 17β-diol (3βAdiol). 3βAdiol is estrogenic in ERα or ERβ positive cells only if they do not express CYP7B1. In this study we show that female CYP7B1–/– mice experience early onset of growth of the uterus and mammary glands and commence estrus cycles 2 days earlier than their wild-type littermates. Adult mammary glands and uteri appear to be under continuous estrogenic stimulation. We conclude that, by cell-specific regulation of the estrogenicity of 3βAdiol, CYP7B1 performs two major tasks: (i) it allows 3βAdiol to have growth inhibitory effects through ERβ and (ii) it permits estradiol-specific activation of estrogen receptors by protection of certain cells from the estrogenic effects of 3βAdiol. When CYP7B1 is inactivated, 3βAdiol activates estrogen receptors indiscriminately, and the overall effect is prolonged and inappropriate exposure to estrogen. PMID:15710898

Atropisomers of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) exhibit stereoselective effects on activation of nuclear receptors in vitro.

PubMed

Pěnčíková, Kateřina; Brenerová, Petra; Svržková, Lucie; Hrubá, Eva; Pálková, Lenka; Vondráček, Jan; Lehmler, Hans-Joachim; Machala, Miroslav

2017-11-09

PCB 136 is an environmentally relevant chiral PCB congener, which has been found in vivo to be present in form of rotational isomers (atropisomers). Its atropselective biotransformation or neurotoxic effects linked with sensitization of ryanodine receptor suggest that it might interact also with other intracellular receptors in a stereospecific manner. However, possible atropselective effects of PCB 136 on nuclear receptor transactivation remain unknown. Therefore, in this study, atropselective effects of PCB 136 on nuclear receptors controlling endocrine signaling and/or expression of xenobiotic and steroid hormone catabolism were investigated. PCB136 atropisomers were found to exert differential effects on estrogen receptor (ER) activation; (+)-PCB 136 was estrogenic, while (-)-PCB 136 was antiestrogenic. In contrast, inhibition of androgen receptor (AR) activity was not stereospecific. Both PCB136 stereoisomers induced the constitutive androgen receptor (CAR)-dependent gene expression; however, no significant stereospecificity of PCB 136 atropisomers was observed. PCB136 was a partial inducer of the pregnane X receptor (PXR)-dependent gene expression. Here, (-)-PCB 136 was a significantly more potent inducer of PXR activity than (+)-PCB 136. Taken together, the present results indicate that at least two nuclear receptors participating in endocrine regulation or metabolism, ER and PXR, could be regulated in an atropselective manner by chiral PCB 136. The enantioselective enrichment of PCB atropisomers in animal and human tissues may thus have significant consequences for endocrine-disrupting effects of chiral ortho-substituted PCB congeners.

Effects of low dose treatment of tributyltin on the regulation of estrogen receptor functions in MCF-7 cells.

PubMed

Sharan, Shruti; Nikhil, Kumar; Roy, Partha

2013-06-01

Endocrine disrupting chemicals are the natural/synthetic compounds which mimic or inhibit the actions of endogenous hormones. Organotin compounds, such as tributyltin (TBT) are typical environmental contaminants and suspected endocrine-disrupting chemical. The present study evaluates the estrogenic potential of this compound in vitro in ER (+) breast adenocarcinoma, MCF-7 cell line. Our data showed that tributyltin chloride (TBTCl) had agonistic activities for estrogen receptor-α (ER-α). Its estrogenic potential was checked using cell proliferation assay, aromatase assay, transactivation assay, and protein expression analysis. Low dose treatment of TBTCl had a proliferative effect on MCF-7 cells and resulted in up-regulation of aromatase enzyme activity and enhanced estradiol production in MCF-7 cells. Immunofluorescence staining showed translocation of ER-α from cytoplasm to nucleus and increased expression of ER-α, 3β-HSD and aromatase on treatment with increasing doses of TBTCl. Further, to decipher the probable signaling pathways involved in its action, the MCF-7 cells were transfected with different pathway dependent luciferase reporter plasmids (CRE, SRE, NF-κB and AP1). A significant increase in CRE and SRE and decrease in NF-κB regulated pathway were observed (p<0.05). Our results thus showed that the activation of SRE by TBTCl may be due to ligand dependent ER-α activation of the MAPK pathway and increased phosphorylation of ERK. In summary, the present data suggests that low dose of tributyltin genomically and non-genomically augmented estrogen dependent signaling by targeting various pathways. Copyright © 2013 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, Yohan; Chung, Kwang Chul, E-mail: kchung@yonsei.ac.kr

Highlights: Black-Right-Pointing-Pointer ZNF131 directly interacts with ER{alpha}. Black-Right-Pointing-Pointer The binding affinity of ZNF131 to ER{alpha} increases upon E2 stimulation. Black-Right-Pointing-Pointer ZNF131 inhibits ER{alpha}-mediated trans-activation by suppressing its homo-dimerization. Black-Right-Pointing-Pointer ZNF131 inhibits ER{alpha}-dimerization and E2-induced breast cancer cell proliferation. Black-Right-Pointing-Pointer ZNF131 inhibits estrogen signaling by acting as an ER{alpha}-co-repressor. -- Abstract: Steroid hormone estrogen elicits various physiological functions, many of which are mediated through two structurally and functionally distinct estrogen receptors, ER{alpha} and ER{beta}. The functional role of zinc finger protein 131 (ZNF131) is poorly understood, but it is assumed to possess transcriptional regulation activity due to the presence of amore » DNA binding motif. A few recent reports, including ours, revealed that ZNF131 acts as a negative regulator of ER{alpha} and that SUMO modification potentiates the negative effect of ZNF131 on estrogen signaling. However, its molecular mechanism for ER{alpha} inhibition has not been elucidated in detail. Here, we demonstrate that ZNF131 directly interacts with ER{alpha}, which consequently inhibits ER{alpha}-mediated trans-activation by suppressing its homo-dimerization. Moreover, we show that the C-terminal region of ZNF131 containing the SUMOylation site is necessary for its inhibition of estrogen signaling. Taken together, these data suggest that ZNF131 inhibits estrogen signaling by acting as an ER{alpha}-co-repressor.« less

Estrogen protection against EAE modulates the microbiota and mucosal-associated regulatory cells.

PubMed

Benedek, Gil; Zhang, Jun; Nguyen, Ha; Kent, Gail; Seifert, Hilary A; Davin, Sean; Stauffer, Patrick; Vandenbark, Arthur A; Karstens, Lisa; Asquith, Mark; Offner, Halina

2017-09-15

Sex hormones promote immunoregulatory effects on multiple sclerosis. In the current study we evaluated the composition of the gut microbiota and the mucosal-associated regulatory cells in estrogen or sham treated female mice before and after autoimmune encephalomyelitis (EAE) induction. Treatment with pregnancy levels of estrogen induces changes in the composition and diversity of gut microbiota. Additionally, estrogen prevents EAE-associated changes in the gut microbiota and might promote the enrichment of bacteria that are associated with immune regulation. Our results point to a possible cross-talk between the sex hormones and the gut microbiota, which could promote neuroprotection. Copyright © 2017 Elsevier B.V. All rights reserved.

The ERα-PI3K Cascade in Proopiomelanocortin Progenitor Neurons Regulates Feeding and Glucose Balance in Female Mice

PubMed Central

Zhu, Liangru; Xu, Pingwen; Cao, Xuehong; Yang, Yongjie; Hinton, Antentor Othrell; Xia, Yan; Saito, Kenji; Yan, Xiaofeng; Zou, Fang; Ding, Hongfang; Wang, Chunmei; Yan, Chunling; Saha, Pradip; Khan, Sohaib A.; Zhao, Jean; Fukuda, Makoto; Tong, Qingchun; Clegg, Deborah J.; Chan, Lawrence

2015-01-01

Estrogens act upon estrogen receptor (ER)α to inhibit feeding and improve glucose homeostasis in female animals. However, the intracellular signals that mediate these estrogenic actions remain unknown. Here, we report that anorexigenic effects of estrogens are blunted in female mice that lack ERα specifically in proopiomelanocortin (POMC) progenitor neurons. These mutant mice also develop insulin resistance and are insensitive to the glucose-regulatory effects of estrogens. Moreover, we showed that propyl pyrazole triol (an ERα agonist) stimulates the phosphatidyl inositol 3-kinase (PI3K) pathway specifically in POMC progenitor neurons, and that blockade of PI3K attenuates propyl pyrazole triol-induced activation of POMC neurons. Finally, we show that effects of estrogens to inhibit food intake and to improve insulin sensitivity are significantly attenuated in female mice with PI3K genetically inhibited in POMC progenitor neurons. Together, our results indicate that an ERα-PI3K cascade in POMC progenitor neurons mediates estrogenic actions to suppress food intake and improve insulin sensitivity. PMID:26375425

Hormonal regulation of serum Lp (a) levels. Opposite effects after estrogen treatment and orchidectomy in males with prostatic carcinoma.

PubMed Central

Henriksson, P; Angelin, B; Berglund, L

1992-01-01

Serum concentrations of lipoprotein (a) [Lp (a)] were determined in two groups of elderly males suffering from prostatic carcinoma, who were randomized to treatment with estrogen (n = 15) or orchidectomy (n = 16). Estrogen was given as oral ethinylestradiol, 150 micrograms daily, combined with intramuscular polyestradiol phosphate, 80 mg/mo. The baseline levels were similar in both groups, but 6 mo after initiation of therapy, serum Lp (a) levels were decreased approximately 50% in the estrogen-treated group (P less than 0.001) in contrast to a 20% increase (P less than 0.01) in the orchidectomized group. Concomitantly, LDL cholesterol decreased by 30% and HDL cholesterol increased by almost 60% in the estrogen-treated patients. There was no relationship between the change in LDL cholesterol and Lp (a) reduction. In conclusion, Lp (a) levels in males were found to drastically decrease upon estrogen treatment and to increase after orchidectomy, suggesting that sex hormones, and particularly estrogens, exert a regulatory role on the serum Lp (a) level in man. Images PMID:1532586

The ERα-PI3K Cascade in Proopiomelanocortin Progenitor Neurons Regulates Feeding and Glucose Balance in Female Mice.

PubMed

Zhu, Liangru; Xu, Pingwen; Cao, Xuehong; Yang, Yongjie; Hinton, Antentor Othrell; Xia, Yan; Saito, Kenji; Yan, Xiaofeng; Zou, Fang; Ding, Hongfang; Wang, Chunmei; Yan, Chunling; Saha, Pradip; Khan, Sohaib A; Zhao, Jean; Fukuda, Makoto; Tong, Qingchun; Clegg, Deborah J; Chan, Lawrence; Xu, Yong

2015-12-01

Estrogens act upon estrogen receptor (ER)α to inhibit feeding and improve glucose homeostasis in female animals. However, the intracellular signals that mediate these estrogenic actions remain unknown. Here, we report that anorexigenic effects of estrogens are blunted in female mice that lack ERα specifically in proopiomelanocortin (POMC) progenitor neurons. These mutant mice also develop insulin resistance and are insensitive to the glucose-regulatory effects of estrogens. Moreover, we showed that propyl pyrazole triol (an ERα agonist) stimulates the phosphatidyl inositol 3-kinase (PI3K) pathway specifically in POMC progenitor neurons, and that blockade of PI3K attenuates propyl pyrazole triol-induced activation of POMC neurons. Finally, we show that effects of estrogens to inhibit food intake and to improve insulin sensitivity are significantly attenuated in female mice with PI3K genetically inhibited in POMC progenitor neurons. Together, our results indicate that an ERα-PI3K cascade in POMC progenitor neurons mediates estrogenic actions to suppress food intake and improve insulin sensitivity.

Estrogen Signaling in Metabolic Inflammation

PubMed Central

Monteiro, Rosário; Teixeira, Diana; Calhau, Conceição

2014-01-01

There is extensive evidence supporting the interference of inflammatory activation with metabolism. Obesity, mainly visceral obesity, is associated with a low-grade inflammatory state, triggered by metabolic surplus where specialized metabolic cells such as adipocytes activate cellular stress initiating and sustaining the inflammatory program. The increasing prevalence of obesity, resulting in increased cardiometabolic risk and precipitating illness such as cardiovascular disease, type 2 diabetes, fatty liver, cirrhosis, and certain types of cancer, constitutes a good example of this association. The metabolic actions of estrogens have been studied extensively and there is also accumulating evidence that estrogens influence immune processes. However, the connection between these two fields of estrogen actions has been underacknowledged since little attention has been drawn towards the possible action of estrogens on the modulation of metabolism through their anti-inflammatory properties. In the present paper, we summarize knowledge on the modification inflammatory processes by estrogens with impact on metabolism and highlight major research questions on the field. Understanding the regulation of metabolic inflammation by estrogens may provide the basis for the development of therapeutic strategies to the management of metabolic dysfunctions. PMID:25400333

Ovarian steroids, stem cells and uterine leiomyoma: therapeutic implications

PubMed Central

Moravek, Molly B.; Yin, Ping; Ono, Masanori; Coon V, John S.; Dyson, Matthew T.; Navarro, Antonia; Marsh, Erica E.; Chakravarti, Debabrata; Kim, J. Julie; Wei, Jian-Jun; Bulun, Serdar E.

2015-01-01

BACKGROUND Uterine leiomyoma is the most common benign tumor in women and is thought to arise from the clonal expansion of a single myometrial smooth muscle cell transformed by a cellular insult. Leiomyomas cause a variety of symptoms, including abnormal uterine bleeding, pelvic pain, bladder or bowel dysfunction, and recurrent pregnancy loss, and are the most common indication for hysterectomy in the USA. A slow rate of cell proliferation, combined with the production of copious amounts of extracellular matrix, accounts for tumor expansion. A common salient feature of leiomyomas is their responsiveness to steroid hormones, thus providing an opportunity for intervention. METHODS A comprehensive search of PUBMED was conducted to identify peer-reviewed literature published since 1980 pertinent to the roles of steroid hormones and somatic stem cells in leiomyoma, including literature on therapeutics that target steroid hormone action in leiomyoma. Reviewed articles were restricted to English language only. Studies in both animals and humans were reviewed for the manuscript. RESULTS Estrogen stimulates the growth of leiomyomas, which are exposed to this hormone not only through ovarian steroidogenesis, but also through local conversion of androgens by aromatase within the tumors themselves. The primary action of estrogen, together with its receptor estrogen receptor α (ERα), is likely mediated via induction of progesterone receptor (PR) expression, thereby allowing leiomyoma responsiveness to progesterone. Progesterone has been shown to stimulate the growth of leiomyoma through a set of key genes that regulate both apoptosis and proliferation. Given these findings, aromatase inhibitors and antiprogestins have been developed for the treatment of leiomyoma, but neither treatment results in complete regression of leiomyoma, and tumors recur after treatment is stopped. Recently, distinct cell populations were discovered in leiomyomas; a small population showed stem-progenitor cell properties, and was found to be essential for ovarian steroid-dependent growth of leiomyomas. Interestingly, these stem-progenitor cells were deficient in ERα and PR and instead relied on the strikingly higher levels of these receptors in surrounding differentiated cells to mediate estrogen and progesterone action via paracrine signaling. CONCLUSIONS It has been well established that estrogen and progesterone are involved in the proliferation and maintenance of uterine leiomyoma, and the majority of medical treatments currently available for leiomyoma work by inhibiting steroid hormone production or action. A pitfall of these therapeutics is that they decrease leiomyoma size, but do not completely eradicate them, and tumors tend to regrow once treatment is stopped. The recent discovery of stem cells and their paracrine interactions with more differentiated cell populations within leiomyoma has the potential to provide the missing link between developing therapeutics that temper leiomyoma growth and those that eradicate them. PMID:25205766

Differences in Regional Brain Metabolism Associated with Specific Formulations of Hormone Therapy in Postmenopausal Women at Risk for AD

PubMed Central

Silverman, Daniel H.S.; Geist, Cheri L.; Kenna, Heather A; Williams, Katherine; Wroolie, Tonita; Powers, Bevin; Brooks, John; Rasgon, Natalie L

2010-01-01

Summary Differential cerebral metabolic effects of various hormone therapy formulations, and their associations with cognitive status, remain to be established. The principal aim of the current study wasto assess relationships between regional cerebral metabolism and estrogen-based hormone therapies. Postmenopausal women (n=53) at elevated risk for Alzheimer’s disease (AD) were on estrogen-containing hormone therapy for at least one year prior to enrollment in a prospective, randomized clinical trial. Subjects underwent an FDG-PET scan, along with neuropsychological, medical, and demographic assessments at time of enrollment, to be repeated one year following randomization to hormone therapy continuation versus discontinuation, and results from analyses of the baseline assessments are reported here. Across all subjects, years of endogenous estrogen exposure correlated most closely with metabolism in right superior frontal gyrus (p<0.0005). Women taking 17β-estradiol (E) performed 3 standard deviations higher in verbal memory than women taking conjugated equine estrogen (CEE), and their verbal memory performance positively correlated with metabolism in Wernicke’s (p=0.003) and auditory association (p=0.002) areas. Women taking progesterone-plus-estrogen had lower metabolism than women taking unopposed estrogen within the mesial and inferior lateral temporal regions (p<0.0005) and the inferior frontal cortex, contralateral to Broca’s area (p<0.0005). In conclusion, particular areas of relatively preserved metabolism were seen in women with more years of endogenous estrogen exposure, as well as in women taking estradiol-based formulations or estrogen therapies unopposed by progesterone, together suggesting regionally specific neuroprotective estrogenic effects. PMID:20810219

Differences in regional brain metabolism associated with specific formulations of hormone therapy in postmenopausal women at risk for AD.

PubMed

Silverman, Daniel H S; Geist, Cheri L; Kenna, Heather A; Williams, Katherine; Wroolie, Tonita; Powers, Bevin; Brooks, John; Rasgon, Natalie L

2011-05-01

Differential cerebral metabolic effects of various hormone therapy formulations, and their associations with cognitive status, remain to be established. The principal aim of the current study was to assess relationships between regional cerebral metabolism and estrogen-based hormone therapies. Postmenopausal women (n=53) at elevated risk for Alzheimer's disease (AD) were on estrogen-containing hormone therapy for at least one year prior to enrollment in a prospective, randomized clinical trial. Subjects underwent an FDG-PET scan, along with neuropsychological, medical, and demographic assessments at time of enrollment, to be repeated one year following randomization to hormone therapy continuation versus discontinuation, and results from analyses of the baseline assessments are reported here. Across all subjects, years of endogenous estrogen exposure correlated most closely with metabolism in right superior frontal gyrus (p<0.0005). Women taking 17β-estradiol (E) performed three standard deviations higher in verbal memory than women taking conjugated equine estrogen (CEE), and their verbal memory performance positively correlated with metabolism in Wernicke's (p=0.003) and auditory association (p=0.002) areas. Women taking progesterone-plus-estrogen had lower metabolism than women taking unopposed estrogen within the mesial and inferior lateral temporal regions (p<0.0005) and the inferior frontal cortex, contralateral to Broca's area (p<0.0005). In conclusion, particular areas of relatively preserved metabolism were seen in women with more years of endogenous estrogen exposure, as well as in women taking estradiol-based formulations or estrogen therapies unopposed by progesterone, together suggesting regionally specific neuroprotective estrogenic effects. Copyright © 2010 Elsevier Ltd. All rights reserved.

The Effect of Estradiol-17(beta), Goitrogen (T3), and Flutamide on Gene Expression in Medaka, Oryzias latipes

DOE Office of Scientific and Technical Information (OSTI.GOV)

E.Haut, J

Concern has been generated over the discovery of endocrine disrupting chemicals in rivers near sewage outflows. The presence of endocrine disrupting chemicals such as estradiol-17{beta} has been associated with a reduction of reproductive success in fish and an increase in the female phenotype and gonadal intersex in fish downstream of sewage treatment facilities. Such effects are believed to result from a disruption in the normal estrogenic pathways since estrogen plays a vital role in reproduction, sexual differentiation, the developments of secondary sex characteristics, and ovulation. Most studies have focused on the effect of a single endocrine disruptor on a singlemore » gene which does not provide for the interaction between genes. Microarray technology has made it possible to put an entire genome on a single chip so that researchers can get a clearer picture of the interaction of genes expressed in a cell and changes of said interactions when those cells are exposed to various conditions. Medaka males were exposed to known endocrine disruptors, estradial-17{beta} and goitrogen, and medaka females were exposed to flutamide. All treatments were then compared to controls. Total RNA was extracted from the livers of both treated and untreated males and hybridized to a microarray chip designed to have EST sequences specific to medaka. ESTs were identified through two-channel microarray analysis and compared to GenBank using blastn searches to identify up regulated genes. Choriogenins H and L, zona radiata, and vitellogenin, previously shown to be estrogen-induced in male fish were identified. Heat shock proteins (hsp70, hsp90, and hsp8) were also induced by estradiol-17{beta}, as was choriogenin Hminor. Exposure to goitrogen (T3) resulted in the induced expression of glutathione S-transferase and a GABA receptor protein in male medaka. Treatment with flutamide, an antiandrogen, caused the up regulation of choriogenin L, choriogenin Hminor, and zona radiata-2 in female medaka. Further study of the genes identified in this study may serve as possible biomarkers to signal the effects caused by the presence of endocrine disruptors and provide a screening mechanism for the presence of estrogens in the environment. Microarray technology may provide a means to screen multiple biomarkers simultaneously and provide a more rapid and accurate tool for assessing endocrine disruption due to environmental pollutants.« less

Exploring Androgen-Regulated Pathways in Teleost Fish Using Transcriptomics and Proteomics

PubMed Central

Martyniuk, Christopher J.; Denslow, Nancy D.

2012-01-01

In the environment, there are aquatic pollutants that disrupt androgen signaling in fish. Laboratory and field-based experiments have utilized omics technologies to characterize the molecular mechanisms underlying androgen-receptor agonism/antagonism. Transcriptomics and proteomics studies with 17β-trenbolone, a growth-promoting pharmaceutical found in water systems surrounding cattle feed lots, and androgens such as 17α-methyltestosterone and 17α-methyldihydrotestosterone, have been conducted in ovary and liver of fish that include the fathead minnow (FHM) (Pimephales promelas), common carp (Cyprinus carpio), Qurt medaka (Oryzias latipes), and zebrafish (Danio rerio). In this mini-review, we survey recent omics studies in fish and reveal that, despite the diversity of species and tissues examined, there are common cellular responses that are observed with waterborne androgenic treatments. Recurring themes in gene ontology include apoptosis, transport and oxidation of lipids, synthesis and transport of hormones, immune response, protein metabolism, and cell proliferation. However, we also discuss other mechanisms other than androgen receptor (AR) activation, such as responses to toxicant stress, estrogen receptor agonism, aromatization of androgens into estrogens, and inhibitory feedback mechanisms by high levels of androgens that may also explain molecular responses in fish. To further explore androgen-responsive protein networks, a sub-network enrichment analysis was performed on protein data collected from the livers of female FHMs exposed to 17β-trenbolone. We construct a putative AR-regulated protein/cell process network in the liver that includes B-lymphocyte differentiation, xenobiotic clearance, low-density lipoprotein oxidation, proliferation of smooth muscle cells, and permeability of blood vessels. We demonstrate that construction of protein networks can offer insight into cell processes that are potentially regulated by androgens. PMID:22596056

Unique effect of 4-hydroxyestradiol and its methylation metabolites on lipid and cholesterol profiles in ovariectomized female rats.

PubMed

Wang, Pan; Zhu, Bao-Ting

2017-04-05

Animal studies have shown that endogenous estrogens such as 17β-estradiol (E 2 ) can modulate lipid profiles in vivo, and this effect is generally thought to be mediated by the estrogen receptors (ERs). The present study sought to test a hypothesis that some of the endogenous estrogen metabolites that have very weak estrogenic activity may exert some of their modulating effects on lipid metabolism in an ER-independent manner. Using ovariectomized female rats as an in vivo model, we found that 4-hydroxyestradiol (4-OH-E 2 ) has a markedly stronger effect in reducing the adipocyte size and serum cholesterol level in rats compared to E 2 , despite the weaker estrogenic activity of 4-OH-E 2 . Moreover, when E 2 or 4-OH-E 2 is used in combination with ICI-182,780 (an ER antagonist), some of their lipid-modulating effects are not blocked by this antiestrogen. Interestingly, two of the O-methylation metabolites of 4-OH-E 2 , namely, 4-methoxyestradiol and 4-methoxyestrone, which have much weaker estrogenic activity, were also found to have similar lipid-modulating effects compared to 4-OH-E 2 . Mechanistically, up-regulation of the expression of leptin, cytochrome P450 7A1 and LXRα genes is observed in the liver of animals treated with E 2 or 4-OH-E 2 , and the up-regulation is essentially not inhibited by co-treatment with ICI-182,780. These results demonstrate that some of the endogenous E 2 metabolites are functionally important modulators of lipid metabolic profiles in vivo. In addition, our findings indicate that an ER-independent pathway likely mediates some of the lipid-modulating effects of endogenous estrogens and their metabolic derivatives. Copyright © 2017 Elsevier B.V. All rights reserved.

Estrogen and progesterone signalling in the normal breast and its implications for cancer development.

PubMed

Hilton, Heidi N; Clarke, Christine L; Graham, J Dinny

2018-05-05

The ovarian hormones estrogen and progesterone are master regulators of the development and function of a broad spectrum of human tissues, including the breast, reproductive and cardiovascular systems, brain and bone. Acting through the nuclear estrogen (ER) and progesterone receptors (PR), both play complex and essential coordinated roles in the extensive development of the lobular alveolar epithelial structures of the normal breast during puberty, the normal menstrual cycle and pregnancy. The past decade has seen major advances in understanding the mechanisms of action of estrogen and progesterone in the normal breast and in the delineation of the complex hierarchy of cell types regulated by ovarian hormones in this tissue. There is evidence for a role for both ER and PR in driving breast cancer, and both are favourable prognostic markers with respect to outcome. In this review, we summarize current knowledge of the mechanisms of action of ER and PR in the normal breast, and implications for the development and management of breast cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

[Effects of total flavonoids in Astragali Complanati Semen on liver lipid level and ERα expression on liver in hyperlipidemia rats with kidney-Yang deficiency pattern].

PubMed

Tang, Xiao-Ran; Wang, Jing-Xia; Fu, Lu; Yao, Jun-Kai; Li, Si-Ming; Gao, Xue-Min; Zhang, Jian-Jun

2018-06-01

Menopausal women appear lipid metabolism disorder with the ovarian function decline and the estrogen levels decreased. Modern clinical usually use estrogen replacement therapy and with long time application with lots of side effect appear. Traditional Chinese medicine has more secure and effective methords,using warming Yang drugs and methods. And the previous study proves the Chinese medicine Astragali Complanati Semen water extraction has a good role in regulation of blood lipids. Because of the liver is the most important organ on regulating metabolism, therefore this study aimed to evaluate the effects of total flavonoids in Astragali Complanati Semen(TFS)on liverlipid level and ERα expressionon liver in hyperlipidemia rats with kidney-Yang deficiency pattern to explore the substance basis and mechanism of Astragali Complanati Semen in regulate lipid effect and clarify traditional Chinese medicine advantages and features. This experiment uses hyperlipidemia rats with kidney-Yang deficiency pattern with bilateral ovariectomized and fed with high fat diet for 6 weeks. And rats of sham operation group and model group rats were intragastrilly(ig) with saline, estrogen group were intragastrilly with estrogen(0.2 mg·kg⁻¹). And three TFS group were intragastrilly with TFS at dose 28.5, 57, 114 mg·kg⁻¹ for 8 weeks. At the same time, TC, TG, LDL-C,HDL-C liver weight, liver index, uterine weight, uterine index, serum estrogen level, FSH levels and liver pathology, liver estrogen receptor expression were detected, weighting and calculating their organ index. The experimental results compared with the model group, TFS 114 mg·kg⁻¹ decreased the level of liver TG ( P <0.05), TC ( P <0.001) and LDL-C ( P <0.001) and increased the level of HDL-C ( P <0.05). Compared with the model group, estrogen group increased the level of blood serum ( P <0.001) and decreased the level of FSH ( P <0.001). In addition, compared with sham operation group,model group decreased the protein expression of ERα（ P <0.01）. Compared with the model group, estrogen group increased the protein expression of ERα significantly（ P <0.001）.TFS mid-dose group and TFS high-dose group is increased the protein expression of ERα（ P <0.01, P <0.001）.In a conclusion,Flavonoids is the main active ingredient of Astragali Complanati Semen. The mechanism of it maybe is enhancing the estrogen receptor sensitivity or the number of estrogen receptors, amplifying the signal after the receptor conduction, which could result in lipid-lowering effect. Copyright© by the Chinese Pharmaceutical Association.

G protein-coupled receptor 30 contributes to improved remyelination after cuprizone-induced demyelination.

PubMed

Hirahara, Yukie; Matsuda, Ken Ichi; Yamada, Hisao; Saitou, Akira; Morisaki, Shinsuke; Takanami, Keiko; Boggs, Joan M; Kawata, Mitsuhiro

2013-03-01

Estrogen exerts neuroprotective and promyelinating actions. The therapeutic effect has been shown in animal models of multiple sclerosis, in which the myelin sheath is specifically destroyed in the central nervous system. However, it remains unproven whether estrogen is directly involved in remyelination via the myelin producing cells, oligodendrocytes, or which estrogen receptors are involved. In this study, we found that the membrane-associated estrogen receptor, the G protein-coupled receptor 30 (GPR30), also known as GPER, was expressed in oligodendrocytes in rat spinal cord and corpus callosum. Moreover, GPR30 was expressed throughout oligodendrocyte differentiation and promyelinating stages in primary oligodendrocyte cultures derived from rat spinal cords and brains. To evaluate the role of signaling via GPR30 in promyelination, a specific agonist for GPR30, G1, was administered to a rat model of demyelination induced by cuprizone treatment. Histological examination of the corpus callosum with oligodendrocyte differentiation stage-specific markers showed that G1 enhanced oligodendrocyte maturation in corpus callosum of cuprizone-treated animals. It also enhanced oligodendrocyte ensheathment of dorsal root ganglion (DRG) neurons in co-culture and myelination in cuprizone-treated animals. This study is the first evidence that GPR30 signaling promotes remyelination by oligodendrocytes after demyelination. GPR30 ligands may provide a novel therapy for the treatment of multiple sclerosis. Copyright © 2012 Wiley Periodicals, Inc.

Hippocampal learning, memory, and neurogenesis: Effects of sex and estrogens across the lifespan in adults.

PubMed

Duarte-Guterman, Paula; Yagi, Shunya; Chow, Carmen; Galea, Liisa A M

2015-08-01

This article is part of a Special Issue "Estradiol and Cognition". There are sex differences in hippocampus-dependent cognition and neurogenesis suggesting that sex hormones are involved. Estrogens modulate certain forms of spatial and contextual memory and neurogenesis in the adult female rodent, and to a lesser extent male, hippocampus. This review focuses on the effects of sex and estrogens on hippocampal learning, memory, and neurogenesis in the young and aged adult rodent. We discuss how factors such as the type of estrogen, duration and dose of treatment, timing of treatment, and type of memory influence the effects of estrogens on cognition and neurogenesis. We also address how reproductive experience (pregnancy and mothering) and aging interact with estrogens to modulate hippocampal cognition and neurogenesis in females. Given the evidence that adult hippocampal neurogenesis plays a role in long-term spatial memory and pattern separation, we also discuss the functional implications of regulating neurogenesis in the hippocampus. Copyright © 2015 Elsevier Inc. All rights reserved.

Differential microRNA expression is associated with androgen receptor expression in breast cancer.

PubMed

Shi, Yaqin; Yang, Fang; Sun, Zijia; Zhang, Wenwen; Gu, Jun; Guan, Xiaoxiang

2017-01-01

The androgen receptor (AR) is frequently expressed in breast cancer; however, its prognostic value remains unclear. AR expression in breast cancer has been associated with improved outcomes in estrogen receptor (ER)‑positive breast cancer compared with ER‑negative disease. Eliminating AR function in breast cancer is critically important for breast cancer progression. However, the mechanism underlying AR regulation remains poorly understood. The study of microRNAs (miRNAs) has provided important insights into the pathogenesis of hormone‑dependent cancer. To determine whether miRNAs function in the AR regulation of breast cancer, the present study performed miRNA expression profiling in AR‑positive and ‑negative breast cancer cell lines. A total of 153 miRNAs were differentially expressed in AR‑positive compared with AR‑negative breast cancer cells; 52 were upregulated and 101 were downregulated. A number of these have been extensively associated with breast cancer cell functions, including proliferation, invasion and drug‑resistance. Furthermore, through pathway enrichment analysis, signaling pathways associated with the prediction targets of the miRNAs were characterized, including the vascular endothelial growth factor and mammalian target of rapamycin signaling pathways. In conclusion, the results of the present study indicated that the expression of miRNAs may be involved in the mechanism underlying AR regulation of breast cancer, and may improve understanding of the role of AR in breast cancer.

Transforming growth factor-β signaling: emerging stem cell target in metastatic breast cancer?

PubMed Central

Tan, Antoinette R.; Alexe, Gabriela; Reiss, Michael

2009-01-01

In most human breast cancers, lowering of TGFβ receptor- or Smad gene expression combined with increased levels of TGFβs in the tumor microenvironment is sufficient to abrogate TGFβs tumor suppressive effects and to induce a mesenchymal, motile and invasive phenotype. In genetic mouse models, TGFβ signaling suppresses de novo mammary cancer formation but promotes metastasis of tumors that have broken through TGFβ tumor suppression. In mouse models of “triple-negative” or basal-like breast cancer, treatment with TGFβ neutralizing anti-bodies or receptor kinase inhibitors strongly inhibits development of lung- and bone metastases. These TGFβ antagonists do not significantly affect tumor cell proliferation or apoptosis. Rather, they de-repress anti-tumor immunity, inhibit angiogenesis and reverse the mesenchymal, motile, invasive phenotype characteristic of basal-like and HER2-positive breast cancer cells. Patterns of TGFβ target genes upregulation in human breast cancers suggest that TGFβ may drive tumor progression in estrogen-independent cancer, while it mediates a suppressive host cell response in estrogen-dependent luminal cancers. In addition, TGFβ appears to play a key role in maintaining the mammary epithelial (cancer) stem cell pool, in part by inducing a mesenchymal phenotype, while differentiated, estrogen receptor-positive, luminal cells are unresponsive to TGFβ because the TGFBR2 receptor gene is transcriptionally silent. These same cells respond to estrogen by downregulating TGFβ, while antiestrogens act by upregulating TGFβ. This model predicts that inhibiting TGFβ signaling should drive the differentiation of mammary stem cells into ductal cells. Consequently, TGFβ antagonists may convert basal-like or HER2-positive cancers to a more epithelioid, non-proliferating (and, perhaps, non-metastatic) phenotype. Conversely, these agents might antagonize the therapeutic effects of anti-estrogens in estrogen-dependent luminal cancers. These predictions need to be addressed prospectively in clinical trials and should inform the selection of patient populations most likely to benefit from this novel anti-metastatic therapeutic approach. PMID:18841463

Leptin interferes with the effects of the antiestrogen ICI 182,780 in MCF-7 breast cancer cells.

PubMed

Garofalo, Cecilia; Sisci, Diego; Surmacz, Eva

2004-10-01

Obesity is a risk factor for breast cancer development in postmenopausal women and correlates with shorter disease-free and overall survival in breast cancer patients, regardless of menopausal status. Adipose tissue is a major source of leptin, a cytokine regulating energy balance and controlling different processes in peripheral tissues, including breast cancer cell growth. Here, we investigated whether leptin can counteract antitumorigenic activities of the antiestrogen ICI 182,780 in breast cancer cells. Mitogenic response to leptin and the effects of leptin on ICI 182,780-dependent growth inhibition were studied in MCF-7 estrogen receptor alpha-positive breast cancer cells. The expression of leptin receptor and the activation of signaling pathways were studied by Western immunoblotting. The interference of leptin with ICI 182,780-induced estrogen receptor alpha degradation was probed by Western immunoblotting, fluorescence microscopy, and pulse-chase experiments. Leptin effects on estrogen receptor alpha-dependent transcription in the presence and absence of ICI 182,780 were studied by luciferase reporter assays and chromatin immunoprecipitation. MCF-7 cells were found to express the leptin receptor and respond to leptin with cell growth and activation the signal transducers and activators of transcription 3, extracellular signal-regulated kinase-1/2, and Akt/GSK3/pRb pathways. The exposure of cells to 10 nmol/L ICI 182,780 blocked cell proliferation, induced rapid estrogen receptor alpha degradation, inhibited nuclear estrogen receptor alpha expression, and reduced estrogen receptor alpha-dependent transcription from estrogen response element-containing promoters. All of these effects of ICI 182,780 were significantly attenuated by simultaneous treatment of cells with 100 ng/mL leptin. Leptin interferes with the effects of ICI 182,780 on estrogen receptor alpha in breast cancer cells. Thus, high leptin levels in obese breast cancer patients might contribute to the development of antiestrogen resistance.

Sex Steroids and Bone Health Status in Men

PubMed Central

Chin, Kok-Yong; Ima-Nirwana, Soelaiman

2012-01-01

Male osteoporosis is a health problem which deserves more attention as nearly 30% of osteoporotic fractures happen in men aged 50 years and above. Although men do not experience an accelerated bone loss phase and testosterone deficiency is not a universal characteristic for aged men, osteoporosis due to age-related testosterone deficiency does have a negative impact on bone health status of men. Observations from epidemiological studies indicate that elderly men with higher testosterone can preserve their BMD better and thus are less prone to fracture. Observations on men with estrogen resistance or aromatase deficiency indicate that estrogen is equally important in the maintenance of bone health status. This had been validated in several epidemiological studies which found that the relationships between estrogen and bone health indices are significant and sometimes stronger than testosterone. Studies on the relationship between quantitative ultrasound and bone remodeling markers suggest that testosterone and estrogen may have differential effects on bone, but further evidence was needed. In conclusion, both testosterone and estrogen are important in the maintenance of bone health in men. PMID:23150727

Localization of androgen receptors and estrogen receptors in the same cells of the songbird brain.

PubMed Central

Gahr, M

1990-01-01

Estrogens and androgens each have unique effects but act together for the neural differentiation and control of sexual behaviors in male vertebrates, such as the canary. The neuronal basis for these synergistic effects is elusive because the spatial relation between estrogen target cells and androgen target cells is unknown. This study localized estrogen receptor (ER)-containing cells by using immunocytochemistry and androgen receptor (AR)-containing cells by using autoradiography in the same sections of the male canary brain. Three cell types, those containing only ER, those containing only AR, and those containing both ER and AR, were found in tissue-specific frequencies. The midbrain nucleus intercollicularis exhibited the highest number of cells expressing both ER and AR, whereas ER and AR are expressed only in disjunctive cell populations in the forebrain nucleus hyperstriatalis ventrale, pars caudale. Synergistic effects of androgens and estrogens for the neural behavorial control could result from cells containing both ER and AR (intracellular) and from neural circuits containing ER and AR in different cells (intercellular). Images PMID:2251286

Combination of low-concentration of novel phytoestrogen (8,9)-furanyl-pterocarpan-3-ol from Pachyrhizus erosus attenuated tamoxifen-associated growth inhibition on breast cancer T47D cells

PubMed Central

Nurrochmad, Arief; Lukitaningsih, Endang; Monikawati, Ameilinda; Septhea, Dita Brenna; Meiyanto, Edy

2013-01-01

Objective To investigate the estrogenic effect of (8,9)-furanyl-pterocarpan-3-ol (FPC) on growth of human breast cancer T47D cells and the interactions between the FPC and tamoxifen (TAM), on the growth of estrogen receptor-dependent breast cancer T47D cells. Methods The proliferation effect of FPC were conducted on T47D cells in vitro by MTT test. T47D cells were treated with FPC alone (0.01-200 µmol/L) or in combination with TAM 20 nmol/L. Furthermore, the expression of ERα or c-Myc were also determined by immunohistochemistry. Results The results indicated that administration of an anti-estrogen TAM showed growth inhibitory effect on T47D cells, wheraes co-administered with low concentration (less than 1 µmol/L) of FPC attenuated to promote cell proliferation. In contrast, the combination of TAM with higher doses (more than 20 µmol/L) of FPC showed growth inhibitory. This result was supported by immunocytochemistry studies that the administration of 20 nmol/L TAM down-regulated ER-α and c-Myc, but the combination of 20 nmol/L TAM and 1 µmol/L FPC robustly up-regulated expression of ER-α. Thus, the reduced growth inhibition of TAM 20 nmol/L by FPC 1 µmol/L on T47D cells may act via the modulation of ER-α. Conclusions The findings indicate and suggest that FPC had estrogenic activity at low concentrations and anti-estrogenic effect that are likely to be regulated by c-Myc and estrogen receptors. We also confirm that low concentration of FPC attenuated the growth-inhibitory effects of TAM on mammary tumor prevention. Therefore, the present study suggests that caution is warranted regarding the consumption of dietary FPC by breast cancer patients while on TMA therapy.

The expression of genes involved in myometrial contractility changes during ex situ culture of pregnant human uterine smooth muscle tissue.

PubMed

Ilicic, Marina; Butler, Trent; Zakar, Tamas; Paul, Jonathan W

2017-01-01

Ex situ analyses of human myometrial tissue has been used to investigate the regulation of uterine quiescence and transition to a contractile phenotype. Following concerns about the validity of cultured primary cells, we examined whether myometrial tissue undergoes culture-induced changes ex situ that may affect the validity of in vitro models. To determine whether human myometrial tissue undergoes culture-induced changes ex situ in Estrogen receptor 1 (ESR1), Prostaglandin-endoperoxide synthase 2 (PTGS2) and Oxytocin receptor (OXTR) expression. Additionally, to determine whether culture conditions approaching the in vivo environment influence the expression of these key genes. Term non-laboring human myometrial tissues were cultured in the presence of specific treatments, including; serum supplementation, progesterone and estrogen, cAMP, PMA, stretch or NF-κB inhibitors. ESR1, PTGS2 and OXTR mRNA abundance after 48 h culture was determined using quantitative RT-PCR. Myometrial tissue in culture exhibited culture-induced up-regulation of ESR1 and PTGS2 and down-regulation of OXTR mRNA expression. Progesterone prevented culture-induced increase in ESR1 expression. Estrogen further up-regulated PTGS2 expression. Stretch had no direct effect, but blocked the effects of progesterone and estrogen on ESR1 and PTGS2 expression. cAMP had no effect whereas PMA further up-regulated PTGS2 expression and prevented decline of OXTR expression. Human myometrial tissue in culture undergoes culture-induced gene expression changes consistent with transition toward a laboring phenotype. Changes in ESR1, PTGS2 and OXTR expression could not be controlled simultaneously. Until optimal culture conditions are determined, results of in vitro experiments with myometrial tissues should be interpreted with caution.

Steroid receptor coactivator-1 mediates letrozole induced downregulation of postsynaptic protein PSD-95 in the hippocampus of adult female rats.

PubMed

Liu, Mengying; Huangfu, Xuhong; Zhao, Yangang; Zhang, Dongmei; Zhang, Jiqiang

2015-11-01

Hippocampus local estrogen which is converted from androgen that catalyzed by aromatase has been shown to play important roles in the regulation of learning and memory as well as cognition through action on synaptic plasticity, but the underlying mechanisms are poorly understood. Steroid receptor coactivator-1 (SRC-1) is one of the coactivators of steroid nuclear receptors; it is widely distributed in brain areas that related to learning and memory, reproductive regulation, sensory and motor information integration. Previous studies have revealed high levels of SRC-1 immunoreactivities in the hippocampus; it is closely related to the levels of synaptic proteins such as PSD-95 under normal development or gonadectomy, but its exact roles in the regulation of these proteins remains unclear. In this study, we used aromatase inhibitor letrozole in vivo and SRC-1 RNA interference in vitro to investigate whether SRC-1 mediated endogenous estrogen regulation of hippocampal PSD-95. The results revealed that letrozole injection synchronously decreased hippocampal SRC-1 and PSD-95 in a dose-dependant manner. Furthermore, when SRC-1 specific shRNA pool was applied to block the expression of SRC-1 in the primary hippocampal neuron culture, both immunocytochemistry and Western blot revealed that levels of PSD-95 were also decreased significantly. Taking together, these results provided the first evidence that SRC-1 mediated endogenous estrogen regulation of hippocampal synaptic plasticity by targeting the expression of synaptic protein PSD-95. Additionally, since letrozole is frequently used to treat estrogen-sensitive breast cancer, the above results also indicate its potential side effects in clinical administration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Elevated seminal plasma estradiol and epigenetic inactivation of ESR1 and ESR2 is associated with CP/CPPS

PubMed Central

Nesheim, Nils; Ellem, Stuart; Dansranjavin, Temuujin; Hagenkötter, Christina; Berg, Elena; Schambeck, Rupert; Schuppe, Hans-Christian; Pilatz, Adrian; Risbridger, Gail; Weidner, Wolfgang

2018-01-01

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is associated with urinary tract symptoms and hormonal imbalances amongst others. The heterogeneous clinical presentation, unexplored molecular background and lack of prostate biopsies complicate therapy. Here, using liquid biopsies, we performed a comprehensive translational study on men diagnosed with CP/CPPS type III (n = 50; median age 39.8, range 23–65) and age-matched controls (n = 61; median age 36.8, range 20–69), considering biochemical parameters of blood and ejaculates, and epigenetic regulation of the estrogen receptor genes (ESR1 and ESR2) in leukocytes isolated from blood (systemic regulation) and in somatic cells isolated from ejaculates (local regulation). We found elevated 17β-estradiol (E2) levels in seminal plasma, but not in blood plasma, that was significantly associated with CP/CPPS and impaired urinary tract symptoms. In ejaculated somatic cells of CP/CPPS patients we found that ESR1 and ESR2 were both significantly higher methylated in CpG-promoters and expressionally down-regulated in comparison to controls. Mast cells are reported to contribute to CP/CPPS and are estrogen responsive. Consistent with this, we found that E2 –treatment of human mast cell lines (HMC-1 and LAD2) resulted in altered cytokine and chemokine expression. Interestingly, in HMC-1 cells, possessing epigenetically inactivated ESR1 and ESR2, E2 –treatment led to a reduced transcription of a number of inflammatory genes. Overall, these data suggest that elevated local E2 levels associate with an epigenetic down-regulation of the estrogen receptors and have a prominent role in CP/CPPS. Investigating E2 levels in semen could therefore serve as a promising biomarker to select patients for estrogen targeted therapy. PMID:29731970

Elevated seminal plasma estradiol and epigenetic inactivation of ESR1 and ESR2 is associated with CP/CPPS.

PubMed

Nesheim, Nils; Ellem, Stuart; Dansranjavin, Temuujin; Hagenkötter, Christina; Berg, Elena; Schambeck, Rupert; Schuppe, Hans-Christian; Pilatz, Adrian; Risbridger, Gail; Weidner, Wolfgang; Wagenlehner, Florian; Schagdarsurengin, Undraga

2018-04-13

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is associated with urinary tract symptoms and hormonal imbalances amongst others. The heterogeneous clinical presentation, unexplored molecular background and lack of prostate biopsies complicate therapy. Here, using liquid biopsies, we performed a comprehensive translational study on men diagnosed with CP/CPPS type III ( n = 50; median age 39.8, range 23-65) and age-matched controls ( n = 61; median age 36.8, range 20-69), considering biochemical parameters of blood and ejaculates, and epigenetic regulation of the estrogen receptor genes ( ESR1 and ESR2 ) in leukocytes isolated from blood (systemic regulation) and in somatic cells isolated from ejaculates (local regulation). We found elevated 17β-estradiol (E 2 ) levels in seminal plasma, but not in blood plasma, that was significantly associated with CP/CPPS and impaired urinary tract symptoms. In ejaculated somatic cells of CP/CPPS patients we found that ESR1 and ESR2 were both significantly higher methylated in CpG-promoters and expressionally down-regulated in comparison to controls. Mast cells are reported to contribute to CP/CPPS and are estrogen responsive. Consistent with this, we found that E 2 -treatment of human mast cell lines (HMC-1 and LAD2) resulted in altered cytokine and chemokine expression. Interestingly, in HMC-1 cells, possessing epigenetically inactivated ESR1 and ESR2, E 2 -treatment led to a reduced transcription of a number of inflammatory genes. Overall, these data suggest that elevated local E 2 levels associate with an epigenetic down-regulation of the estrogen receptors and have a prominent role in CP/CPPS. Investigating E 2 levels in semen could therefore serve as a promising biomarker to select patients for estrogen targeted therapy.

Estrogens and human papilloma virus oncogenes regulate human ether-à-go-go-1 potassium channel expression.

PubMed

Díaz, Lorenza; Ceja-Ochoa, Irais; Restrepo-Angulo, Iván; Larrea, Fernando; Avila-Chávez, Euclides; García-Becerra, Rocío; Borja-Cacho, Elizabeth; Barrera, David; Ahumada, Elías; Gariglio, Patricio; Alvarez-Rios, Elizabeth; Ocadiz-Delgado, Rodolfo; Garcia-Villa, Enrique; Hernández-Gallegos, Elizabeth; Camacho-Arroyo, Ignacio; Morales, Angélica; Ordaz-Rosado, David; García-Latorre, Ethel; Escamilla, Juan; Sánchez-Peña, Luz Carmen; Saqui-Salces, Milena; Gamboa-Dominguez, Armando; Vera, Eunice; Uribe-Ramírez, Marisela; Murbartián, Janet; Ortiz, Cindy Sharon; Rivera-Guevara, Claudia; De Vizcaya-Ruiz, Andrea; Camacho, Javier

2009-04-15

Ether-à-go-go-1 (Eag1) potassium channels are potential tools for detection and therapy of numerous cancers. Here, we show human Eag1 (hEag1) regulation by cancer-associated factors. We studied hEag1 gene expression and its regulation by estradiol, antiestrogens, and human papillomavirus (HPV) oncogenes (E6/E7). Primary cultures from normal placentas and cervical cancer tissues; tumor cell lines from cervix, choriocarcinoma, keratinocytes, and lung; and normal cell lines from vascular endothelium, keratinocytes, and lung were used. Reverse transcription-PCR (RT-PCR) experiments and Southern blot analysis showed Eag1 expression in all of the cancer cell types, normal trophoblasts, and vascular endothelium, in contrast to normal keratinocytes and lung cells. Estradiol and antiestrogens regulated Eag1 in a cell type-dependent manner. Real-time RT-PCR experiments in HeLa cells showed that Eag1 estrogenic regulation was strongly associated with the expression of estrogen receptor-alpha. Eag1 protein was detected by monoclonal antibodies in normal placenta and placental blood vessels. Patch-clamp recordings in normal trophoblasts treated with estradiol exhibited potassium currents resembling Eag1 channel activity. Eag1 gene expression in keratinocytes depended either on cellular immortalization or the presence of HPV oncogenes. Eag1 protein was found in keratinocytes transfected with E6/E7 HPV oncogenes. Cell proliferation of E6/E7 keratinocytes was decreased by Eag1 antibodies inhibiting channel activity and by the nonspecific Eag1 inhibitors imipramine and astemizole; the latter also increased apoptosis. Our results propose novel oncogenic mechanisms of estrogen/antiestrogen use and HPV infection. We also suggest Eag1 as an early indicator of cell proliferation leading to malignancies and a therapeutic target at early stages of cellular hyperproliferation.

Hepatic gene expression patterns following trauma-hemorrhage: effect of posttreatment with estrogen.

PubMed

Yu, Huang-Ping; Pang, See-Tong; Chaudry, Irshad H

2013-01-01

The aim of this study was to examine the role of estrogen on hepatic gene expression profiles at an early time point following trauma-hemorrhage in rats. Groups of injured and sham controls receiving estrogen or vehicle were killed 2 h after injury and resuscitation, and liver tissue was harvested. Complementary RNA was synthesized from each RNA sample and hybridized to microarrays. A large number of genes were differentially expressed at the 2-h time point in injured animals with or without estrogen treatment. The upregulation or downregulation of a cohort of 14 of these genes was validated by reverse transcription-polymerase chain reaction. This large-scale microarray analysis shows that at the 2-h time point, there is marked alteration in hepatic gene expression following trauma-hemorrhage. However, estrogen treatment attenuated these changes in injured animals. Pathway analysis demonstrated predominant changes in the expression of genes involved in metabolism, immunity, and apoptosis. Upregulation of low-density lipoprotein receptor, protein phosphatase 1, regulatory subunit 3C, ring-finger protein 11, pyroglutamyl-peptidase I, bactericidal/permeability-increasing protein, integrin, αD, BCL2-like 11, leukemia inhibitory factor receptor, ATPase, Cu transporting, α polypeptide, and Mk1 protein was found in estrogen-treated trauma-hemorrhaged animals. Thus, estrogen produces hepatoprotection following trauma-hemorrhage likely via antiapoptosis and improving/restoring metabolism and immunity pathways.

Determination of water quality, toxicity and estrogenic activity in a nearshore marine environment in Rio de Janeiro, Southeastern Brazil.

PubMed

do Nascimento, Marilia Teresa Lima; Santos, Ana Dalva de Oliveira; Felix, Louise Cruz; Gomes, Giselle; de Oliveira E Sá, Mariana; da Cunha, Danieli Lima; Vieira, Natividade; Hauser-Davis, Rachel Ann; Baptista Neto, José Antonio; Bila, Daniele Maia

2018-03-01

Endocrine disrupting compounds (EDCs) can be found in domestic sewage, wastewater treatment plant effluents, natural water, rivers, lakes and in the marine environment. Jurujuba Sound, located in the state of Rio de Janeiro, Southeastern Brazil, receives untreated sewage into its waters, one the main sources of aquatic contamination in this area. In this context, the aim of the present study was to evaluate the estrogenic potential of water sampled from different depths and from areas with differential contamination levels throughout Jurujuba Sound. Water quality was evaluated and acute toxicity assays using Allviibrio fischeri were conducted, while estrogenic activity of the water samples was determined by a Yeast Estrogen Screening assay (YES). Water quality was mostly within the limits established for marine waters by the Brazilian legislation, with only DOC and ammoniacal nitrogen levels above the maximum permissible limits. No acute toxicity effects were observed in the Allivibrio fisheri assay. The YES assay detected moderate estrogenic activity in bottom water samples from 3 sampling stations, ranging from 0.5 to 3.2ngL -1 , as well as in one surface water sample. Estrogenic activity was most frequently observed in samples from the bottom of the water column, indicating adsorption of estrogenic compounds to the sediment. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of estradiol on the expression of angiogenic factors in epithelial ovarian cancer.

PubMed

Valladares, Macarena; Plaza-Parrochia, Francisca; Lépez, Macarena; López, Daniela; Gabler, Fernando; Gayan, Patricio; Selman, Alberto; Vega, Margarita; Romero, Carmen

2017-11-01

Ovarian cancer presents a high angiogenesis (formation of new blood vessels) regulated by pro-angiogenic factors, mainly vascular endothelial growth factor (VEGF) and nerve growth factor (NGF). An association between endogenous levels of estrogen and increased risk of developing ovarian cancer has been reported. Estrogen action is mediated by the binding to its specific receptors (ERα and ERβ), altered ERα/ERβ ratio may constitute a marker of ovarian carcinogenesis progression. To determine the effect of estradiol through ERα on the expression of NGF and VEGF in epithelial ovarian cancer (EOC). Levels of phosphorylated estrogen receptor alpha (pERα) were evaluated in well, moderate and poorly differentiated EOC samples (EOC-I, EOC-II, EOC-III). Additionally, ovarian cancer explants were stimulated with NGF (0, 10 and 100 ng/ml) and ERα, ERβ and pERα levels were detected. Finally, human ovarian surface epithelial (HOSE) and epithelial ovarian cancer (A2780) cell lines were stimulated with estradiol, where NGF and VEGF protein levels were evaluated. In tissues, ERs were detected being pERα levels significantly increased in EOC-III samples compared with EOC-I (p<0.05). Additionally, ovarian explants treated with NGF increased pERα levels meanwhile total ERα and ERβ levels did not change. Cell lines stimulated with estradiol revealed an increase of NGF and VEGF protein levels (p<0.05). Estradiol has a positive effect on pro-angiogenic factors such as NGF and VEGF expression in EOC, probably through the activation of ERα; generating a positive loop induced by NGF increasing pERα levels in epithelial ovarian cells.

Bisphenol A differentially activates protein kinase C isoforms in murine placental tissue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, Wenjuan; Huang, Hui; Wang, Yanfei

2013-06-01

Bisphenol A is utilized to make polycarbonate plastics and is an environmental pollutant. Recent research has indicated that it is an endocrine disruptor and may interfere with reproductive processes. Our lab has previously shown that bisphenol A could regulate corticotrophin releasing hormone and aromatase in cultured placental cells. In the present study, the effect of bisphenol A on these two genes in the placenta was investigated in mice. Pregnant ICR mice were gavaged with bisphenol A at 2, 20 and 200 mg/kg body weight/day from E13 to E16 and were euthanized at E17. Compared to the control mice, increased plasmamore » estrogen and corticotrophin releasing hormone were observed in bisphenol A-treated mice. Messenger RNA quantification indicated that placental crh but not cyp19 was induced in mice treated with bisphenol A. Tracking the related signaling pathway, we found that protein kinase C ζ/λ and δ were activated in the placentas of bisphenol A-treated mice. As the gene promoter of crh contains CRE and the half site of ERE, either phospho-PKC or estrogen could stimulate the gene transactivation. These results indicate that bisphenol A might increase plasma concentrations of estradiol, testosterone, corticotrophin releasing hormone and placental phospho-PKC ζ/λ and δ in mice. Ultimately, the incidence of premature birth in these mice could increase. - Highlights: • The pollutant bisphenol A differentially activated PKC isoforms in the placenta. • CRE-binding activity in the nuclear protein of placenta was increased. • Bisphenol A induces CRH mRNA expression in mice.« less

Unliganded estrogen receptor α stimulates bone sialoprotein gene expression.

PubMed

Takai, Hideki; Matsumura, Hiroyoshi; Matsui, Sari; Kim, Kyung Mi; Mezawa, Masaru; Nakayama, Yohei; Ogata, Yorimasa

2014-04-10

Estrogen is one of the steroid hormones essential for skeletal development. The estrogen receptor (ER) is a transcription factor and a member of the steroid receptor superfamily. There are two different forms of the ER, usually referred to as α and β, each encoded by a separate gene. Hormone-activated ERs form dimers, since the two forms are coexpressed in many cell types. Bone sialoprotein (BSP) is a tissue-specific acidic glycoprotein that is expressed by differentiated osteoblasts, odontoblasts and cementoblasts during the initial formation of mineralized tissue. To determine the molecular basis of the tissue-specific expression of BSP and its regulation by estrogen and the ER, we have analyzed the effects of β-estradiol and ERα on BSP gene transcription. ERα protein levels were increased after ERα overexpression in ROS17/2.8 cells. While BSP mRNA levels were increased by ERα overexpression, the endogenous and overexpressed BSP mRNA levels were not changed by β-estradiol (10(-8)M, 24 h). Luciferase activities of different sized BSP promoter constructs (pLUC3~6) were increased by ERα overexpression, whereas basal and induced luciferase activities by ERα overexpression were not influenced by β-estradiol. Effects of ERα overexpression were abrogated by 2 bp mutations in either the cAMP response element (CRE) or activator protein 1 (AP1)/glucocorticoid response element (GRE). Gel shift analyses showed that ERα overexpression increased binding to the CRE and AP1/GRE elements. Notably, the CRE-protein complexes were disrupted by ERα, CREB and phospho-CREB antibodies. The AP1/GRE-protein complexes were supershifted by the c-Fos antibody. These studies demonstrate that ERα stimulates BSP gene transcription in a ligand-independent manner by targeting the CRE and AP1/GRE elements in the rat BSP gene promoter. Copyright © 2014 Elsevier B.V. All rights reserved.

Differential effects of estrogen and estrogen receptor antagonist, ICI 182 780, on the expression of calbindin-D9k in rat pituitary prolactinoma GH₃ cells.

PubMed

Wang, Wan; Knosp, Engelbert; Tai, Guixiang; Zhao, Yuanzheng; Liang, Qianlei; Guo, Yongchuan

2014-01-01

To detect the effects of 17β-estradiol (E2) on the expression of calbindin-D9k (CaBP-9k) in pituitary GH3 cells, and to determine the antagonistic effect of a selective estrogen receptor (ER) antagonist (ICI 182 780) on CaBP-9k expression. A rat pituitary prolactinoma cell line (GH3 cells) was used in an in vitro model. The localization of CaBP-9k in GH3 cells was observed by immunofluorescence. GH3 cells were cultured with the addition of E2 medium for 24 hours. The levels of CaBP-9k mRNA and protein expression in different groups were analyzed by RT-PCR and Western blot analysis. The ER antagonist, ICI 182 780, was added to GH3 cells before E2 (10(-8) M) at a concentration of 10(-6) M to investigate the regulation of an ER-mediated pathway on CaBP-9k expression. E2 had a stimulatory effect on CaBP-9k expression of GH3 cells in a dose-dependent manner; the level of CaBP-9k expression was higher when treated with a higher concentration of E2. ICI 182 780 suppressed the stimulatory effect of E2 on CaBP-9k expression in GH3 cells. The level of CaBP-9k expression was significantly reduced by co-administration of E2 with ICI 182 780 in GH3 cells. The immunoprecipitation results confirmed that CaBP-9k interacts directly with ERα, and E2 increases the interaction between CaBP-9k and ERα. Estrogen induces CaBP-9k expression via an ERα-mediated pathway and CaBP-9k directly combines with ERα, suggesting that CaBP-9k is involved in the biological effects mediated by an ER pathway in GH3 cells.

Linking the response of endocrine regulated genes to adverse effects on sex differentiation improves comprehension of aromatase inhibition in a Fish Sexual Development Test.

PubMed

Muth-Köhne, Elke; Westphal-Settele, Kathi; Brückner, Jasmin; Konradi, Sabine; Schiller, Viktoria; Schäfers, Christoph; Teigeler, Matthias; Fenske, Martina

2016-07-01

The Fish Sexual Development Test (FSDT) is a non-reproductive test to assess adverse effects of endocrine disrupting chemicals. With the present study it was intended to evaluate whether gene expression endpoints would serve as predictive markers of endocrine disruption in a FSDT. For proof-of-concept, a FSDT according to the OECD TG 234 was conducted with the non-steroidal aromatase inhibitor fadrozole (test concentrations: 10μg/L, 32μg/L, 100μg/L) using zebrafish (Danio rerio). Gene expression analyses using quantitative RT-PCR were included at 48h, 96h, 28days and 63days post fertilization (hpf, dpf). The selection of genes aimed at finding molecular endpoints which could be directly linked to the adverse apical effects of aromatase inhibition. The most prominent effects of fadrozole exposure on the sexual development of zebrafish were a complete sex ratio shift towards males and an acceleration of gonad maturation already at low fadrozole concentrations (10μg/L). Due to the specific inhibition of the aromatase enzyme (Cyp19) by fadrozole and thus, the conversion of C19-androgens to C18-estrogens, the steroid hormone balance controlling the sex ratio of zebrafish was altered. The resulting key event is the regulation of directly estrogen-responsive genes. Subsequently, gene expression of vitellogenin 1 (vtg1) and of the aromatase cyp19a1b isoform (cyp19a1b), were down-regulated upon fadrozole treatment compared to controls. For example, mRNA levels of vtg1 were down-regulated compared to the controls as early as 48 hpf and 96 hpf. Further regulated genes cumulated in pathways suggested to be controlled by endocrine mechanisms, like the steroid and terpenoid synthesis pathway (e.g. mevalonate (diphospho) decarboxylase (mvd), lanosterol synthase (2,3-oxidosqualene-lanosterol cyclase; lss), methylsterol monooxygenase 1 (sc4mol)) and in lipid transport/metabolic processes (steroidogenic acute regulatory protein (star), apolipoprotein Eb (apoEb)). Taken together, this study demonstrated that the existing Adverse Outcome Pathway (AOP) for aromatase inhibition in fish can be translated to the life-stage of sexual differentiation. We were further able to identify MoA-specific marker gene expression which can be instrumental in defining new measurable key events (KE) of existing or new AOPs related to endocrine disruption. Copyright © 2016 The Author(s). Published by Elsevier B.V. All rights reserved.

Characterization of early gonadal development in smallmouth bass (Micropterus dolomieu) and effects of ethinyl estradiol on gonadal differentiation

EPA Science Inventory

Teleosts vary widely in patterns of gonadal sex differentiation, which might lead to differences in how gonadal development is affected by the presence of estrogenic compounds. This makes it difficult to apply our knowledge of model species such as medaka and fathead minnow to o...

DIFFERENTIAL DISPLAY ANALYSES OF THE AMPHIPOD HYALELLA AZTECA EXPOSED TO ETHYNYLESTRADIOL AT THREE DIFFERENT TROPHIC LEVELS

EPA Science Inventory

A study was conducted to determine if differential display could be used to detect differences in gene expression in the amphipod, Hyalella azteca. In a study of synthetic estrogen attenuation in different aquatic media, amphipods were exposed to 20 ng/L 17 a-ethynylestradiol in...

Treatment of BG-1 Ovarian Cancer Cells Expressing Estrogen Receptors with Lambda-cyhalothrin and Cypermethrin Caused a Partial Estrogenicity Via an Estrogen Receptor-dependent Pathway

PubMed Central

Kim, Cho-Won; Go, Ryeo-Eun

2015-01-01

Synthetic pyrethroids (SPs) are the most common pesticides which are recently used for indoor pest control. The widespread use of SPs has resulted in the increased exposure to wild animals and humans. Recently, some SPs are suspected as endocrine disrupting chemicals (EDCs) and have been assessed for their potential estrogenicity by adopting various analyzing assays. In this study, we examined the estrogenic effects of lambda-cyhalothrin (LC) and cypermethrin (CP), the most commonly used pesticides in Korea, using BG-1 ovarian cancer cells expressing estrogen receptors (ERs). To evaluate the estrogenic activities of two SPs, LC and CP, we employed MTT assay and reverse-transcription polymerase chain reaction (RT-PCR) in LC or CP treated BG-1 ovarian cancer cells. In MTT assay, LC (10−6 M) and CP (10−5 M) significantly induced the growth of BG-1 cancer cells. LC or CP-induced cell growth was antagonized by addition of ICI 182,720 (10−8 M), an ER antagonist, suggesting that this effect appears to be mediated by an ER-dependent manner. Moreover, RT-PCR results showed that transcriptional level of cyclin D1, a cell cycle-regulating gene, was significantly up-regulated by LC and CP, while these effects were reversed by co-treatment of ICI 182,780. However, p21, a cyclin D-ckd-4 inhibitor gene, was not altered by LC or CP. Moreover, ERα expression was not significantly changed by LC and CP, while downregulated by E2. Finally, in xenografted mouse model transplanted with human BG-1 ovarian cancer cells, E2 significantly increased the tumor volume compare to a negative control, but LC did not. Taken together, these results suggest that LC and CP may possess estrogenic potentials by stimulating the growth of BG-1 ovarian cancer cells via partially ER signaling pathway associated with cell cycle as did E2, but this estrogenic effect was not found in in vivo mouse model. PMID:26877835

Effects of incubation temperature and estrogen exposure on aromatase activity in the brain and gonads of embryonic alligators.

PubMed Central

Milnes, Matthew R; Roberts, Robert N; Guillette, Louis J

2002-01-01

During embryogenesis, incubation temperature and the hormonal environment influence gonadal differentiation of some reptiles, including all crocodilians. Current evidence suggests that aromatase, the enzyme that converts androgens to estrogens, has a role in sexual differentiation of species that exhibit temperature-dependent sex determination (TSD). During the temperature-sensitive period (TSP) of sex determination, we compared aromatase activity in the brain and gonads of putative male and female alligator embryos to determine if aromatase activity in the embryonic brain could provide the hormonal environment necessary for ovarian development in a TSD species. In addition, we assessed the pattern of aromatase activity in the brain and gonads of embryos treated with estradiol-17beta (E(2)) and incubated at male-producing temperatures to compare enzyme activity in E(2) sex-reversed females to control males and females. This has particular significance regarding wildlife species living in areas contaminated with suspected environmental estrogens. Gonadal aromatase activity remained low during the early stages of the TSP in both sexes and increased late in the TSP only in females. Aromatase activity in the brain increased prior to gonadal differentiation in both sexes. These results suggest that aromatase activity in the brain is not directly responsible for mediating differentiation of the gonad. E(2) exposure at male-producing temperatures resulted in sex-reversed females that had intermediate gonad function and masculinized brain activity. This study indicates the need to examine multiple end points and to determine the persistence of developmental alterations in contaminant-exposed wildlife populations. PMID:12060834

Differential effects of formononetin and cladrin on osteoblast function, peak bone mass achievement and bioavailability in rats.

PubMed

Gautam, Abnish K; Bhargavan, Biju; Tyagi, Abdul M; Srivastava, Kamini; Yadav, Dinesh K; Kumar, Manmeet; Singh, Akanksha; Mishra, Jay S; Singh, Amar Bahadur; Sanyal, Sabyasachi; Maurya, Rakesh; Manickavasagam, Lakshmi; Singh, Sheelendra P; Wahajuddin, Wahajuddin; Jain, Girish K; Chattopadhyay, Naibedya; Singh, Divya

2011-04-01

Dietary soy isoflavones including genistein and daidzein have been shown to have favorable effects during estrogen deficiency in experimental animals and humans. We have evaluated osteogenic effect of cladrin and formononetin, two structurally related methoxydaidzeins found in soy food and other natural sources. Cladrin, at as low as 10 nM, maximally stimulated both osteoblast proliferation and differentiation by activating MEK-Erk pathway. On the other hand, formononetin maximally stimulated osteoblast differentiation at 100 nM that involved p38 MAPK pathway but had no effect on osteoblast proliferation. Unlike daidzein, these two compounds neither activated estrogen receptor in osteoblast nor had any effect on osteoclast differentiation. Daily oral administration of each of these compounds at 10.0 mg kg(-1) day(-1) dose to recently weaned female Sprague-Dawley rats for 30 consecutive days, increased bone mineral density at various anatomic positions studied. By dynamic histomorphometry of bone, we observed that rats treated with cladrin exhibited increased mineral apposition and bone formation rates compared with control, while formononetin had no effect. Cladrin had much better plasma bioavailability compared with formononetin. None of these compounds exhibited estrogen agonistic effect in uteri. Our data suggest that cladrin is more potent among the two in promoting parameters of peak bone mass achievement, which could be attributed to its stimulatory effect on osteoblast proliferation and better bioavailability. To the best of our knowledge, this is the first attempt to elucidate structure-activity relationship between the methoxylated forms of daidzein and their osteogenic effects. Copyright © 2011 Elsevier Inc. All rights reserved.

Estrogen suppresses melatonin-enhanced hyperactivation of hamster spermatozoa

PubMed Central

FUJINOKI, Masakatsu; TAKEI, Gen L.

2015-01-01

Hamster sperm hyperactivation is enhanced by progesterone, and this progesterone-enhanced hyperactivation is suppressed by 17β-estradiol (17βE2) and γ-aminobutyric acid (GABA). Although it has been indicated that melatonin also enhances hyperactivation, it is unknown whether melatonin-enhanced hyperactivation is also suppressed by 17βE2 and GABA. In the present study, melatonin-enhanced hyperactivation was significantly suppressed by 17βE2 but not by GABA. Moreover, suppression of melatonin-enhanced hyperactivation by 17βE2 occurred through non-genomic regulation via the estrogen receptor (ER). These results suggest that enhancement of hyperactivation is regulated by melatonin and 17βE2 through non-genomic regulation. PMID:25959801

Actions of Steroids: New Neurotransmitters

PubMed Central

Cornil, Charlotte A.; Mittelman-Smith, Melinda A.; Rainville, Jennifer R.; Remage-Healey, Luke; Sinchak, Kevin; Micevych, Paul E.

2016-01-01

Over the past two decades, the classical understanding of steroid action has been updated to include rapid, membrane-initiated, neurotransmitter-like functions. While steroids were known to function on very short time spans to induce physiological and behavioral changes, the mechanisms by which these changes occur are now becoming more clear. In avian systems, rapid estradiol effects can be mediated via local alterations in aromatase activity, which precisely regulates the temporal and spatial availability of estrogens. Acute regulation of brain-derived estrogens has been shown to rapidly affect sensorimotor function and sexual motivation in birds. In rodents, estrogens and progesterone are critical for reproduction, including preovulatory events and female sexual receptivity. Membrane progesterone receptor as well as classical progesterone receptor trafficked to the membrane mediate reproductive-related hypothalamic physiology, via second messenger systems with dopamine-induced cell signals. In addition to these relatively rapid actions, estrogen membrane-initiated signaling elicits changes in morphology. In the arcuate nucleus of the hypothalamus, these changes are needed for lordosis behavior. Recent evidence also demonstrates that membrane glucocorticoid receptor is present in numerous cell types and species, including mammals. Further, membrane glucocorticoid receptor influences glucocorticoid receptor translocation to the nucleus effecting transcriptional activity. The studies presented here underscore the evidence that steroids behave like neurotransmitters to regulate CNS functions. In the future, we hope to fully characterize steroid receptor-specific functions in the brain. PMID:27911748

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

Quercetin Induces Dose-Dependent Differential Morphological and Proliferative Changes in Rat Uteri in the Presence and in the Absence of Estrogen

PubMed Central

Shahzad, Huma; Giribabu, Nelli; Sekaran, Muniandy

2015-01-01

Abstract Quercetin could have profound effects on uterine morphology and proliferation, which are known to be influenced by estrogen. This study investigated the effect of quercetin on these uterine parameters in the presence and in the absence of estrogen. Ovariectomized adult female rats received peanut oil, quercetin (10, 50, and 100 mg/kg/day), estrogen, or estrogen+quercetin (10, 50, or 100 mg/kg/day) treatment for 7 consecutive days. At the end of the treatment, uteri were harvested for histological and molecular biological analyses. Distribution of proliferative cell nuclear antigen (PCNA) protein in the uterus was observed by immunohistochemistry. Levels of expression of PCNA protein and mRNA in uterine tissue homogenates were determined by Western blotting and real-time polymerase chain reaction, respectively. Our findings indicated that administration of 10 mg/kg/day of quercetin either alone or with estrogen resulted in decreased uterine expression of PCNA protein and mRNA with the percentage of PCNA-positive cells in uterine luminal and glandular epithelia markedly reduced compared with estrogen-only treatment. Changes in uterine morphology were the opposite of changes observed following estrogen treatment. Treatment with 100 mg/kg/day of quercetin either alone or with estrogen resulted in elevated PCNA protein and mRNA expression. In addition, the percentages of PCNA-positive cells in the epithelia, which line the lumen and glands, were increased with morphological features mimicking changes that occur following estrogen treatment. Following 50 mg/kg/day quercetin treatment, the changes observed were in between those changes that occur following 10 and 100 mg/kg/day quercetin treatment. In conclusion, changes in uterine morphology and proliferation following 10 mg/kg/day quercetin treatment could be attributed to quercetin's antiestrogenic properties, while changes that occur following 100 mg/kg/day quercetin treatment could be attributed to quercetin's estrogenic properties. PMID:26135605

The endocrine disruptor diethylstilbestrol induces adipocyte differentiation and promotes obesity in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hao, Chan-Juan; Cheng, Xue-Jia; Xia, Hong-Fei, E-mail: hongfeixia@yahoo.com.cn

Epidemiology studies indicate that exposure to endocrine disruptors during developmental “window” contributes to adipogenesis and the development of obesity. Implication of endocrine disruptor such as diethylstilbestrol (DES) on adipose tissue development has been poorly investigated. Here we evaluated the effects of DES on adipocyte differentiation in vitro and in vivo, and explored potential mechanism involved in its action. DES induced 3T3-L1 preadipocyte differentiation in a dose-dependent manner, and activated the expression of estrogen receptor (ER) and peroxisome proliferator-acivated receptor (PPAR) γ as well as its target genes required for adipogenesis in vitro. ER mediated the enhancement of DES-induced PPARγ activity.more » Moreover, DES perturbed key regulators of adipogenesis and lipogenic pathway in vivo. In utero exposure to low dose of DES significantly increased body weight, liver weight and fat mass in female offspring at postnatal day (PND) 60. In addition, serum triglyceride and glucose levels were also significantly elevated. These results suggest that perinatal exposure to DES may be expected to increase the incidence of obesity in a sex-dependent manner and can act as a potential chemical stressor for obesity and obesity-related disorders. -- Highlights: ► DES induced adipocyte differentiation in a dose-dependent manner in 3T3-L1 cells. ► DES activated adipogenic critical regulators and markers in vitro and in vivo. ► Perinatal exposure to DES led to the obese phenotype in female offspring. ► DES might be a potential chemical stressor for obesity and obesity-related disorders.« less

Kruppel-like Factor 9 is a Negative Regulator of Ligand-dependent Estrogen Receptor Alpha Signaling in Ishikawa Endometrial Adenocarcinoma Cells

USDA-ARS?s Scientific Manuscript database

Estrogen (E) and progesterone (P), acting through their respective receptors and other nuclear proteins, exhibit opposing activities in target cells. We previously reported that Krüppel-like factor 9 (KLF9) cooperates with progesterone receptor (PR) to facilitate P-dependent gene transcription in ut...

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

DTIC Science & Technology

2005-04-01

tumors correlates with an unfavorable prognosis (Ariazi 2002; Lu 2001; Suzuki 2004; Vanacker 1999). The transcriptional activity of ERRa is not inhibited...SA. 101:6570-5. Needham, M ., S. Raines, J. McPheat, C. Stacey, J. Ellston, S. Hoare, and M . Parker. 2000. Differential interaction of steroid hormone...R. Graves, M . Wright, and B.M. Spiegelman. 1998. A cold- inducible coactivator of nuclear receptors linked to adaptive thermogenesis. Cell. 92:829- 39

Exogenous hormonal regulation in breast cancer cells by phytoestrogens and endocrine disruptors.

PubMed

Albini, A; Rosano, C; Angelini, G; Amaro, A; Esposito, A I; Maramotti, S; Noonan, D M; Pfeffer, U

2014-01-01

Observations on the role of ovarian hormones in breast cancer growth, as well as interest in contraception, stimulated research into the biology of estrogens. The identification of the classical receptors ERα and ERβ and the transmembrane receptor GPER and the resolution of the structure of the ligand bound to its receptor established the principal molecular mechanisms of estrogen action. The presence of estrogen-like compounds in many plants used in traditional medicine or ingested as food ingredients, phytoestrogens, as well as the estrogenic activities of many industrial pollutants and pesticides, xenoestrogens, have prompted investigations into their role in human health. Phyto- and xenoestrogens bind to the estrogen receptors with a lower affinity than the endogenous estrogens and can compete or substitute the hormone. Xenoestrogens, which accumulate in the body throughout life, are believed to increase breast cancer risk, especially in cases of prenatal and prepuberal exposure whereas the role of phytoestrogens is still a matter of debate. At present, the application of phytoestrogens appears to be limited to the treatment of post-menopausal symptoms in women where the production of endogenous estrogens has ceased. In this review we discuss chemistry, structure and classification, estrogen signaling and the consequences of the interactions of estrogens, phytoestrogens and xenoestrogens with their receptors, the complex interactions of endogenous and exogenous ligands, the evaluation of the health risks related to xenoestrogens, and the perspectives toward the synthesis of potent third generation selective estrogen receptor modulators (SERMs).

Exogenous Hormonal Regulation in Breast Cancer Cells by Phytoestrogens and Endocrine Disruptors

PubMed Central

Albini, A.; Rosano, C.; Angelini, G.; Amaro, A.; Esposito, A.I.; Maramotti, S.; Noonan, D.M.; Pfeffer, U.

2014-01-01

Observations on the role of ovarian hormones in breast cancer growth, as well as interest in contraception, stimulated research into the biology of estrogens. The identification of the classical receptors ERα and ERβ and the transmembrane receptor GPER and the resolution of the structure of the ligand bound to its receptor established the principal molecular mechanisms of estrogen action. The presence of estrogen-like compounds in many plants used in traditional medicine or ingested as food ingredients, phytoestrogens, as well as the estrogenic activities of many industrial pollutants and pesticides, xenoestrogens, have prompted investigations into their role in human health. Phyto- and xenoestrogens bind to the estrogen receptors with a lower affinity than the endogenous estrogens and can compete or substitute the hormone. Xenoestrogens, which accumulate in the body throughout life, are believed to increase breast cancer risk, especially in cases of prenatal and prepuberal exposure whereas the role of phytoestrogens is still a matter of debate. At present, the application of phytoestrogens appears to be limited to the treatment of post-menopausal symptoms in women where the production of endogenous estrogens has ceased. In this review we discuss chemistry, structure and classification, estrogen signaling and the consequences of the interactions of estrogens, phytoestrogens and xenoestrogens with their receptors, the complex interactions of endogenous and exogenous ligands, the evaluation of the health risks related to xenoestrogens, and the perspectives toward the synthesis of potent third generation selective estrogen receptor modulators (SERMs). PMID:24304271

Estrogen signaling through the G protein-coupled estrogen receptor regulates granulocyte activation in fish.

PubMed

Cabas, Isabel; Rodenas, M Carmen; Abellán, Emilia; Meseguer, José; Mulero, Victoriano; García-Ayala, Alfonsa

2013-11-01

Neutrophils are major participants in innate host responses. It is well known that estrogens have an immune-modulatory role, and some evidence exists that neutrophil physiology can be altered by these molecules. Traditionally, estrogens act via classical nuclear estrogen receptors, but the identification of a G protein-coupled estrogen receptor (GPER), a membrane estrogen receptor that binds estradiol and other estrogens, has opened up the possibility of exploring additional estrogen-mediated effects. However, information on the importance of GPER for immunity, especially, in neutrophils is scant. In this study, we report that gilthead seabream (Sparus aurata L.) acidophilic granulocytes, which are the functional equivalent of mammalian neutrophils, express GPER at both mRNA and protein levels. By using a GPER selective agonist, G1, it was found that GPER activation in vitro slightly reduced the respiratory burst of acidophilic granulocytes and drastically altered the expression profile of several genes encoding major pro- and anti-inflammatory mediators. In addition, GPER signaling in vivo modulated adaptive immunity. Finally, a cAMP analog mimicked the effects of G1 in the induction of the gene coding for PG-endoperoxide synthase 2 and in the induction of CREB phosphorylation, whereas pharmacological inhibition of protein kinase A superinduced PG-endoperoxide synthase 2. Taken together, our results demonstrate for the first time, to our knowledge, that estrogens are able to modulate vertebrate granulocyte functions through a GPER/cAMP/protein kinase A/CREB signaling pathway and could establish therapeutic targets for several immune disorders in which estrogens play a prominent role.

Characterization of a cis-acting element involved in cell-specific expression of the zebrafish brain aromatase gene.

PubMed

Le Page, Yann; Menuet, Arnaud; Kah, Olivier; Pakdel, Farzad

2008-10-01

The cytochrome P450 Aromatase is the key enzyme catalyzing the conversion of androgens into estrogens. In zebrafish, the brain aromatase is encoded by cyp19b. Expression of cyp19b is restricted to radial glial cells bordering forebrain ventricles and is strongly stimulated by estrogens during development. At the promoter level, we have previously shown that an estrogen responsive element (ERE) is required for induction by estrogens. Here, we investigated the role of ERE flanking regions in the control of cell-specific expression. First, we show that a 20 bp length motif, named G x RE (glial x responsive element), acts in synergy with the ERE to mediate the estrogenic induction specifically in glial cells. Second, we demonstrate that, in vitro, this sequence binds factors exclusively present in glial or neuro-glial cells and is able to confer a glial specificity to an artificial estrogen-dependent gene. Taken together, these results contribute to the understanding of the molecular mechanisms allowing cyp19b regulation by estrogens and allowed to identify a promoter sequence involved in the strong estrogen inducibility of cyp19b which is specific for glial cells. The exceptional aromatase activity measured in the brain of teleost fish could rely on such mechanisms.

The role of estrogen and androgen receptors in bone health and disease

PubMed Central

2014-01-01

Mouse models with cell-specific deletion of the estrogen receptor (ER) α, the androgen receptor (AR) or the receptor activator of nuclear factor κB ligand (RANKL), as well as cascade-selective estrogenic compounds have provided novel insights into the function and signalling of ERα and AR. The studies reveal that the effects of estrogens on trabecular versus cortical bone mass are mediated by direct effects on osteoclasts and osteoblasts, respectively. The protection of cortical bone mass by estrogens is mediated via ERα, using a non-nucleus-initiated mechanism. By contrast, the AR of mature osteoblasts is indispensable for the maintenance of trabecular bone mass in male mammals, but not required for the anabolic effects of androgens on cortical bone. Most unexpectedly, and independently of estrogens, ERα in osteoblast progenitors stimulates Wnt signalling and periosteal bone accrual in response to mechanical strain. RANKL expression in B lymphocytes, but not T lymphocytes, contributes to the loss of trabecular bone caused by estrogen deficiency. In this Review, we summarize this evidence and discuss its implications for understanding the regulation of trabecular and cortical bone mass; the integration of hormonal and mechanical signals; the relative importance of estrogens versus androgens in the male skeleton; and, finally, the pathogenesis and treatment of osteoporosis. PMID:24042328

Estrogen Regulation of Duodenal Bicarbonate Secretion and Sex-Specific Protection of Human Duodenum

PubMed Central

Tuo, Biguang; Wen, Guorong; Wei, Jinqi; Liu, Xuemei; Wang, Xue; Zhang, Yalin; Wu, Huichao; Dong, Xiao; Chow, Jimmy Y.C.; Vallon, Volker; Dong, Hui

2011-01-01

BACKGROUND & AIMS The reason that women have a lower prevalence of duodenal ulcer is not clear. We investigated whether estrogen regulates human duodenal bicarbonate secretion (DBS) and whether this process accounts for sex differences in the prevalence of duodenal ulcer. METHODS We performed an epidemiological study to correlate duodenal ulcer prevalence with sex and age. Proximal DBS was measured from healthy subjects. Estrogen receptor expression was examined in human duodenal mucosa by immunoblot and immunohistochemical analyses. RESULTS Among women, the prevalence of duodenal ulcer was significantly lower than among men. The reduced prevalence was greatest among premenopausal women (20–49 years), who were 3.91–5.09-fold less likely to develop duodenal ulcers than age-matched men; the difference was reduced to ≤1.32-fold among subjects 60 years or older. Premenopausal (20–29 years), but not post-menopausal (60–69 years) women, had significantly higher basal and acid-stimulated DBS than the age-matched men. Basal and acid-stimulated DBS in premenopausal women (20–29 years) were significantly higher than in post-menopausal women (60–69 years), whereas there were no significant differences in basal or acid-stimulated DBS between men that were 20–29 years old or 60–69 years old. Serum levels of estradiol changed in parallel with basal and acid-stimulated DBS during the physiological menstrual cycle in premenopausal women. 17β-estradiol-stimulated DBS was independent of age or sex. Estrogen receptors- and - were detected on plasma membrane and in cytosol of human duodenal epithelial cells. CONCLUSIONS Estrogen regulates human DBS, which could reduce the risk for duodenal ulcer in women and contribute to sex differences in prevalence of duodenal ulcer. PMID:21699784

Estrogen regulation of duodenal bicarbonate secretion and sex-specific protection of human duodenum.

PubMed

Tuo, Biguang; Wen, Guorong; Wei, Jinqi; Liu, Xuemei; Wang, Xue; Zhang, Yalin; Wu, Huichao; Dong, Xiao; Chow, Jimmy Y C; Vallon, Volker; Dong, Hui

2011-09-01

The reason that women have a lower prevalence of duodenal ulcer is not clear. We investigated whether estrogen regulates human duodenal bicarbonate secretion (DBS) and whether this process accounts for sex differences in the prevalence of duodenal ulcer. We performed an epidemiologic study to correlate duodenal ulcer prevalence with sex and age. Proximal DBS was measured from healthy subjects. Estrogen-receptor expression was examined in human duodenal mucosa by immunoblot and immunohistochemical analyses. Among women, the prevalence of duodenal ulcer was significantly lower than among men. The reduced prevalence was greatest among premenopausal women (20-49 y), who were 3.91- to 5.09-fold less likely to develop duodenal ulcers than age-matched men; the difference was reduced to 1.32-fold or less among subjects aged 60 years or older. Premenopausal (20-29 y), but not postmenopausal (60-69 y), women had significantly higher basal and acid-stimulated DBS than the age-matched men. Basal and acid-stimulated DBS in premenopausal women (20-29 y) were significantly higher than in postmenopausal women (60-69 y), whereas there were no significant differences in basal or acid-stimulated DBS between men who were aged 20-29 years or 60-69 years. Serum levels of estradiol changed in parallel with basal and acid-stimulated DBS during the physiological menstrual cycle in premenopausal women. 17β-estradiol-stimulated DBS was independent of age or sex. Estrogen receptors α and β were detected on plasma membranes and in the cytosol of human duodenal epithelial cells. Estrogen regulates human DBS, which could reduce the risk for duodenal ulcer in women and contribute to sex differences in the prevalence of duodenal ulcer. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

G-protein coupled receptor 30 (GPR30): a novel regulator of endothelial inflammation.

PubMed

Chakrabarti, Subhadeep; Davidge, Sandra T

2012-01-01

Estrogen, the female sex hormone, is known to exert anti-inflammatory and anti-atherogenic effects. Traditionally, estrogen effects were believed to be largely mediated through the classical estrogen receptors (ERs). However, there is increasing evidence that G-protein coupled receptor 30 (GPR30), a novel estrogen receptor, can mediate many estrogenic effects on the vasculature. Despite this, the localization and functional significance of GPR30 in the human vascular endothelium remains poorly understood. Given this background, we examined the subcellular location and potential anti-inflammatory roles of GPR30 using human umbilical vein endothelial cells as a model system. Inflammatory changes were induced by treatment with tumor necrosis factor (TNF), a pro-inflammatory cytokine involved in atherogenesis and many other inflammatory conditions. We found that GPR30 was located predominantly in the endothelial cell nuclei. Treatment with the selective GPR30 agonist G-1 partially attenuated the TNF induced upregulation of pro-inflammatory proteins such as intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). This effect was completely abolished by the selective GPR30 antagonist G-15, suggesting that it was indeed mediated in a GPR30 dependent manner. Interestingly, estrogen alone had no effects on TNF-treated endothelium. Concomitant activation of the classical ERs blocked the anti-inflammatory effects of G-1, indicating opposing effects of GPR30 and the classical ERs. Our findings demonstrate that endothelial GPR30 is a novel regulator of the inflammatory response which could be a potential therapeutic target against atherosclerosis and other inflammatory diseases.

Estrogen receptor 1 modulates circadian rhythms in adult female mice.

PubMed

Blattner, Margaret S; Mahoney, Megan M

2014-06-01

Estradiol influences the level and distribution of daily activity, the duration of the free-running period, and the behavioral phase response to light pulses. However, the mechanisms by which estradiol regulates daily and circadian rhythms are not fully understood. We tested the hypothesis that estrogens modulate daily activity patterns via both classical and "non-classical" actions at the estrogen receptor subtype 1 (ESR1). We used female transgenic mice with mutations in their estrogen response pathways; ESR1 knock-out (ERKO) mice and "non-classical" estrogen receptor knock-in (NERKI) mice. NERKI mice have an ESR1 receptor with a mutation in the estrogen-response-element binding domain, allowing only actions via "non-classical" genomic and second messenger pathways. Ovariectomized female NERKI, ERKO, and wildtype (WT) mice were given a subcutaneous capsule with low- or high-dose estradiol and compared with counterparts with no hormone replacement. We measured wheel-running activity in a light:dark cycle and constant darkness, and the behavioral phase response to light pulses given at different points during the subjective day and night. Estradiol increased average daily wheel-running, consolidated activity to the dark phase, and shortened the endogenous period in WT, but not NERKI and ERKO mice. The timing of activity onset during entrainment was advanced in all estradiol-treated animals regardless of genotype suggesting an ESR1-independent mechanism. We propose that estradiol modifies period, activity level, and distribution of activity via classical actions of ESR1 whereas an ESR1 independent mechanism regulates the phase of rhythms.

Estrogen-related receptor alpha is critical for the growth of estrogen receptor-negative breast cancer

PubMed Central

Stein, Rebecca A.; Chang, Ching-yi; Kazmin, Dmitri A.; Way, James; Schroeder, Thies; Wergin, Melanie; Dewhirst, Mark W.; McDonnell, Donald P.

2009-01-01

Expression of estrogen-related receptor alpha (ERRα) has recently been shown to carry negative prognostic significance in breast and ovarian cancers. The specific role of this orphan nuclear receptor in tumor growth and progression, however, is yet to be fully understood. The significant homology between estrogen receptor alpha (ERα) and ERRα initially suggested that these receptors may have similar transcriptional targets. Using the well-characterized ERα-positive MCF-7 breast cancer cell line, we sought to gain a genome-wide picture of ERα-ERRα cross-talk using an unbiased microarray approach. In addition to generating a host of novel ERRα target genes, this study yielded the surprising result that most ERRα-regulated genes are unrelated to estrogen-signaling. The relatively small number of genes regulated by both ERα and ERRα led us to expand our study to the more aggressive and less clinically treatable ERα-negative class of breast cancers. In this setting we found that ERRα expression is required for the basal level of expression of many known and novel ERRα target genes. Introduction of an siRNA directed to ERRα into the highly aggressive breast carcinoma MDA-MB-231 cell line dramatically reduced the migratory potential of these cells. Although stable knockdown of ERRα expression in MDA-MB-231 cells had no impact on in vitro cell proliferation, a significant reduction of tumor growth rate was observed when these cells were implanted as xenografts. Our results confirm a role for ERRα in breast cancer growth and highlight it as a potential therapeutic target for estrogen receptor-negative breast cancer. PMID:18974123

Estrogenic potency of MC-LR is induced via stimulating steroidogenesis: In vitro and in vivo evidence.

PubMed

Hou, Jie; Su, Yujing; Lin, Wang; Guo, Honghui; Li, Li; Anderson, Donald M; Li, Dapeng; Tang, Rong; Chi, Wei; Zhang, Xi

2018-05-14

Waterborne microcystin-LR (MC-LR) has been reported to disrupt sex hormones, while its estrogenic potency remains controversial. We hypothesized that MC-LR could induce estrogenic effects via disrupting sex hormone synthesis, and verified this hypothesis by in vitro and in vivo assays. Effects of MC-LR (1, 10, 100, 500, 1000 and 5000 μg/L) on steroidogenesis were assessed in the H295R cells after 48 h. The contents of 17β-estradiol (E2) and testosterone (T) increased in a non-dose-dependent manner, which showed positive correlations with the expression of steroidogenic genes. In the in vivo assay, adult male zebrafish were exposed to 0.3, 1, 3, 10 and 30 μg/L MC-LR for 30 d. Similarly, E2 and T contents in the testis were increased, accompanied by extensive up-regulation of steroidogenic genes, especially cyp19a. Meanwhile, the percentage of spermatid in the testis declined. In the liver, the vtg1 gene was significantly up-regulated while both the transcriptional and protein levels of the estrogenic receptor (ER) declined. These results indicate that MC-LR induced non-dose-dependent estrogenic effects at environmental concentrations, which may result from steroidogenesis stimulation via a non-ER-mediated pathway. Our findings support a paradigm shift in the risk assessment of MC-LR from traditional toxicity to estrogenic risk, particularly at low concentrations, and emphasize the potential threat to the male reproductive capacity of wildlife in bloom areas. Copyright © 2018 Elsevier Ltd. All rights reserved.

The effects of estradiol and selective estrogen receptor modulators on gene expression and messenger RNA stability in immortalized sheep endometrial stromal cells and human endometrial adenocarcinoma cells.

PubMed

Farnell, Yuhua Z; Ing, Nancy H

2003-03-01

The purpose of this study was to identify an endometrial cell line that maintained the E2 up-regulation of estrogen receptor (ER) mRNA by enhanced message stability and to assess its dependence on ER protein. Estradiol (E2) effects on gene expression were measured in three cell lines: one immortalized from sheep endometrial stroma (ST) and two from human endometrial adenocarcinomas (Ishikawa and ECC-1). E2 up-regulated ER mRNA levels in ST and Ishikawa cells, but down-regulated ER mRNA levels in ECC-1 cells. E2 up-regulated progesterone receptor (PR), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and transforming growth factor-alpha (TGF-alpha) in both Ishikawa and ECC-1 cells. The selective estrogen receptor modulator ICI 182,780 antagonized the E2-induced up-regulation of ER and/or PR mRNA levels in all three cells, while another, GW 5638, antagonized the up-regulation of PR mRNA in Ishikawa and ECC-1 cells. In mechanistic studies, E2 had no effect on ER mRNA stability in ST cells and it destabilized ER mRNA in ECC-1 cells. Thus, Ishikawa cells appear to be the most physiologically relevant cell line in which to study the up-regulation of ER mRNA levels by enhanced mRNA stability. Its antagonism by ICI 182,780 reveals that ER protein is involved in this E2 response.

Glucocorticoids and estrogens modulate the NF-κB pathway differently in the micro- and macrovasculature.

PubMed

Edgar, Abarca-Rojano; Judith, Pacheco-Yépez; Elisa, Drago-Serrano Maria; Rafael, Campos-Rodríguez

2013-12-01

Estrogens and glucocorticoids have synergistic effects in the micro and macrovasculature of endothelial cells (ECs), having pro-inflammatory effects in the former and inhibiting the expression of adhesion molecules in the latter. The molecular basis of these effects in the endothelium has not yet been clarified. We postulate that the ECs of the micro- and macrovasculature have different non-genomic mechanisms that regulate levels of preexisting complexes of glucocorticoids and estrogens with their respective receptors. Since these receptors are regulated by NF-κB, their expression could be critical to the activation of a pro- or anti-inflammatory response. In the macrovasculature the synergistic effects of estrogens and glucocorticoids on ECs may be through the inhibition of NF-κB, leading to the inhibition of the expression of inflammatory molecules. It seems likely that glucocorticoid-receptor and estrogen-receptor complexes directly bind to NF-κB proteins in the macrovasculature, resulting in the inhibition of an excessive proinflammatory response. Further insights into these processes may help clarify the role of the endothelial cells of different vascular beds during the inflammatory response and chronic inflammation, and thus contribute to the design of more effective therapeutic strategies for the prevention of diseases related to inflammation, including atherosclerosis, systemic lupus erythematosus and rheumatoid arthritis. Copyright © 2013 Elsevier Ltd. All rights reserved.

Estrogen regulates the rate of bone turnover but bone balance in ovariectomized rats is modulated by prevailing mechanical strain

NASA Technical Reports Server (NTRS)

Westerlind, K. C.; Wronski, T. J.; Ritman, E. L.; Luo, Z. P.; An, K. N.; Bell, N. H.; Turner, R. T.

1997-01-01

Estrogen deficiency induced bone loss is associated with increased bone turnover in rats and humans. The respective roles of increased bone turnover and altered balance between bone formation and bone resorption in mediating estrogen deficiency-induced cancellous bone loss was investigated in ovariectomized rats. Ovariectomy resulted in increased bone turnover in the distal femur. However, cancellous bone was preferentially lost in the metaphysis, a site that normally experiences low strain energy. No bone loss was observed in the epiphysis, a site experiencing higher strain energy. The role of mechanical strain in maintaining bone balance was investigated by altering the strain history. Mechanical strain was increased and decreased in long bones of ovariectomized rats by treadmill exercise and functional unloading, respectively. Functional unloading was achieved during orbital spaceflight and following unilateral sciatic neurotomy. Increasing mechanical loading reduced bone loss in the metaphysis. In contrast, decreasing loading accentuated bone loss in the metaphysis and resulted in bone loss in the epiphysis. Finally, administration of estrogen to ovariectomized rats reduced bone loss in the unloaded and prevented loss in the loaded limb following unilateral sciatic neurotomy in part by reducing indices of bone turnover. These results suggest that estrogen regulates the rate of bone turnover, but the overall balance between bone formation and bone resorption is influenced by prevailing levels of mechanical strain.

The adverse effect of 4-tert-octylphenol on fat metabolism in pregnant rats via regulation of lipogenic proteins.

PubMed

Kim, Jun; Kang, Eun-Jin; Park, Mee-Na; Kim, Ji-Eun; Kim, Seung-Chul; Jeung, Eui-Bae; Lee, Geun-Shik; Hwang, Dae-Youn; An, Beum-Soo

2015-07-01

Alkylphenols such as 4-tert-octylphenol (OP), nonylphenol, and bisphenol A are classified as endocrine-disrupting chemicals (EDCs). Digestion and metabolism of food are controlled by many endocrine factors, including insulin, glucagon, and estrogen. These factors are differentially regulated during pregnancy. The alteration of nutritional intake and fat metabolism may affect the maintenance of pregnancy and supplementation of nutrients to the fetus, and therefore can cause severe metabolic diseases such as ketosis, marasmus and diabetes mellitus in pregnant individuals. In this study, we examined the effects of OP on fat metabolism in pregnant rats. Ethinyl estradiol (EE) was also administered as an estrogenic positive control. In our results, rats treated with OP showed significantly reduced body weights compared to the control group. In addition, histological analysis showed that the amount of fat deposited in adipocytes was reduced by OP treatment. To study the mechanism of action of OP in fat metabolism, we examined the expression levels of fat metabolism-associated genes in rat adipose tissue and liver by real-time PCR. OP and EE negatively regulated the expression of lipogenic enzymes, including FAS (fatty acid synthase), ACC-1 (acetyl-CoA carboxylase-1), and SCD-1 (stearoyl-CoA desaturase-1). The levels of lipogenic enzyme-associated transcription factors such as C/EBP-α (CAAT enhancer binding protein alpha) and SREBP-1c (sterol regulatory element binding protein-1c) were also reduced in both liver and adipose tissue. In summary, these findings suggest that OP has adverse effects on fat metabolism in pregnant rats and inhibits fat deposition via regulating lipogenic genes in the liver and adipose tissue. The altered fat metabolism by OP may affect the nutrition balance during pregnancy and can cause metabolism-related diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

Estrogen modulation properties of mangiferin and quercetin and the mangiferin metabolite norathyriol.

PubMed

Wilkinson, Ashley S; Taing, Meng-Wong; Pierson, Jean Thomas; Lin, Chun-Nam; Dietzgen, Ralf G; Shaw, P Nicholas; Gidley, Michael J; Monteith, Gregory R; Roberts-Thomson, Sarah J

2015-06-01

Mango fruit contain many bioactive compounds, some of which are transcription factor regulators. Estrogen receptor alpha (ERα) and beta (ERβ) are two regulators of gene transcription that are important in a variety of physiological processes and also in diseases including breast cancer. We examined the ability of the mango constituents quercetin, mangiferin, and the aglycone form of mangiferin, norathyriol, to activate both isoforms of the estrogen receptor. Quercetin and norathyriol decreased the viability of MCF-7 breast cancer cells whereas mangiferin had no effect on MCF-7 cells. We also determined that quercetin and mangiferin selectively activated ERα whereas norathyriol activated both ERα and ERβ. Despite quercetin, mangiferin and norathyriol having similar polyphenolic structural motifs, only norathyriol activated ERβ, showing that bioactive agents in mangoes have very specific biological effects. Such specificity may be important given the often-opposing roles of ERα and ERβ in breast cancer proliferation and other cellular processes.

The human estrogen receptor can regulate exogenous but not endogenous vitellogenin gene promoters in a Xenopus cell line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seiler-Tuyns, A.; Merillat, A.M.; Haefliger, D.N.

Transfection of a human estrogen receptor cDNA expression vector (HEO) into cultured Xenopus kidney cells confers estrogen responsiveness to the recipient cells as demonstrated by the hormone dependent expression of co-transfected Xenopus vitellogenin-CAT chimeric genes. The estrogen stimulation of these vit-CAT genes is dependent upon the presence of the vitellogenin estrogen responsive element (ERE) in their 5{prime} flanking region. Thus, functional human estrogen receptor (hER) can be synthesized in heterologous lower vertebrate cells and can act as a trans-acting regulatory factor that is necessary, together with estradiol, for the induction of the vit-CAT constructs in these cells. In addition, vitellogeninmore » minigenes co-transfected with the HEO expression vector also respond to hormonal stimulation. Their induction is not higher than that of the vit-CAT chimeric genes. It suggests that in the Xenopus kidney cell line B 3.2, the structural parts of the vitellogenin minigenes do not play a role in the induction process. Furthermore, no stabilizing effect of estrogen on vitellogenin mRNA is observed in these cells.« less

G protein-coupled estrogen receptor (GPER) mediates NSCLC progression induced by 17β-estradiol (E2) and selective agonist G1.

PubMed

Liu, Changyu; Liao, Yongde; Fan, Sheng; Tang, Hexiao; Jiang, Zhixiao; Zhou, Bo; Xiong, Jing; Zhou, Sheng; Zou, Man; Wang, Jianmiao

2015-04-01

Estrogen classically drives lung cancer development via estrogen receptor β (ERβ). However, fulvestrant, an anti-estrogen-based endocrine therapeutic treatment, shows limited effects for non-small cell lung cancer (NSCLC) in phase II clinical trials. G protein-coupled estrogen receptor (GPER), a third estrogen receptor that binds to estrogen, has been found to be activated by fulvestrant, stimulating the progression of breast, endometrial, and ovarian cancers. We here demonstrated that cytoplasm-GPER (cGPER) (80.49 %) and nucleus-GPER (53.05 %) were detected by immunohistochemical analysis in NSCLC samples. cGPER expression was related to stages IIIA-IV, lymph node metastasis, and poorly differentiated NSCLC. Selective agonist G1 and 17β-estradiol (E2) promoted the GPER-mediated proliferation, invasion, and migration of NSCLC cells. Additionally, in vitro administration of E2 and G1 increased the number of tumor nodules, tumor grade, and tumor index in a urethane-induced adenocarcinoma model. Importantly, the pro-tumorigenic effects of GPER induced by E2 were significantly reduced by co-administering the GPER inhibitor G15 and the ERβ inhibitor fulvestrant, as compared to administering fulvestrant alone both in vitro and in vivo. Moreover, the phosphorylation of MAPK and Akt was involved in E2/G1-induced GPER activation. In conclusion, our results indicated that a pro-tumor function of GPER exists that mediated E2-/G1-dependent NSCLC progression and showed better efficiency regarding the co-targeting of GPER and ERβ, providing a rationale for further investigation of anti-estrogen clinical therapy.

Effect of halogenated substituents on the metabolism and estrogenic effects of the equine estrogen, equilenin.

PubMed

Liu, Xuemei; Zhang, Fagen; Liu, Hong; Burdette, Joanna E; Li, Yan; Overk, Cassia R; Pisha, Emily; Yao, Jiaqin; van Breemen, Richard B; Swanson, Steven M; Bolton, Judy L

2003-06-01

Estrogen replacement therapy has been correlated with an increased risk for developing breast and endometrial cancers. One potential mechanism of estrogen carcinogenesis involves metabolism of estrogens to 2- and 4-hydroxylated catechols, which are further oxidized to electrophilic/redox active o-quinones that have the potential to both initiate and promote the carcinogenic process. Previously, we showed that the equine estrogens, equilin and equilenin, which are major components of the estrogen replacement formulation Premarin (Wyeth-Ayerst), are primarily metabolized to the catechol, 4-hydroxyequilenin. This catechol was found to autoxidize to an o-quinone causing oxidation and alkylation of DNA in vitro and in vivo. To block catechol formation from equilenin, 4-halogenated equilenin derivatives were synthesized. These derivatives were tested for their ability to bind to the estrogen receptor, induce estrogen sensitive genes, and their potential to form catechol metabolites. We found that the 4-fluoro derivatives were more estrogenic than the 4-chloro and 4-bromo derivatives as demonstrated by a higher binding affinity for estrogen receptors alpha and beta, an enhanced induction of alkaline phosphatase activity in Ishikawa cells, pS2 expression in S30 cells, and PR expression in Ishikawa cells. Incubation of these compounds with tyrosinase in the presence of GSH showed that the halogenated equilenin compounds formed less catechol GSH conjugates than the parent compounds, equilenin and 17beta-hydroxyequilenin. In addition, these halogenated compounds showed less cytotoxicity in the presence of tyrosinase than the parent compounds in S30 cells. Also, as stated above, the 4-fluoro derivatives showed similar estrogenic effects as compared with parent compounds; however, they were less toxic in S30 cells as compared to equilenin and 17beta-equilenin. Because 17beta-hydroxy-4-halogenated equilenin derivatives showed higher estrogenic effects than the halogenated equilenin derivatives in vitro, we studied the relative ability of the 17beta-hydroxy-4-halogenated equilenin derivatives to induce estrogenic effects in the ovariectomized rat model. The 4-fluoro derivative showed higher activity than 4-chloro and 4-bromo derivatives as demonstrated by inducing higher vaginal cellular differentiation, uterine growth, and mammary gland branching. However, 17beta-hydroxy-4-fluoroequilenin showed a lower estrogenic activity than 17beta-hydroxyequilenin and estradiol, which could be due to alternative pharmacokinetic properties for these compounds. These data suggest that the 4-fluoroequilenin derivatives have promise as alternatives to traditional estrogen replacement therapy due to their similar estrogenic properties with less overall toxicity.

Expression patterns of sex differentiation-related genes during gonadal sex change in the protogynous wrasse, Halichoeres trimaculatus.

PubMed

Horiguchi, Ryo; Nozu, Ryo; Hirai, Toshiaki; Kobayashi, Yasuhisa; Nakamura, Masaru

2018-02-01

The three-spot wrasse, Halichoeres trimaculatus, can change sex from female to male (i.e. protogyny) due to sharp decrease in endogenous estrogen. During the sex change, ovarian tissue degenerates and testicular tissue arises newly. Finally, ovarian tissue disappears completely and replaces into mature testis. In order to predict the molecular mechanisms controlling the processes of sex change, we investigated the expression patterns of four genes (rspo1, figla, sox9b and amh), which have been thought to be associated with ovarian/testicular differentiation in vertebrates. Expression levels of rspo1 and figla, which play important roles for ovarian differentiation in vertebrates, were stable until the middle stage of the sex change, and subsequently down-regulated. Therefore, it was indicated that decrease in rspo1 and figla could result from ovarian degeneration. On the other hand, basis on the expression pattern, it was indicated that sox9b and amh, which are involved in testicular differentiation in vertebrates, were implicated in testicular formation and spermatogenesis during the sex change as well. The present results could be fundamental information for investigating the relationship between these factors and E2 depletion, which is crucial trigger for sex change. Copyright © 2017 Elsevier Inc. All rights reserved.

ERα inhibited myocardin-induced differentiation in uterine fibroids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liao, Xing-Hua, E-mail: xinghualiao@hotmail.com; Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457; Li, Jun-Yan

Uterine fibroids, also known as uterine leiomyomas, are a benign tumor of the human uterus and the commonest estrogen-dependent benign tumor found in women. Myocardin is an important transcriptional regulator in smooth and cardiac muscle development. The role of myocardin and its relationship with ERα in uterine fibroids have barely been addressed. We noticed that the expression of myocardin was markedly reduced in human uterine fibroid tissue compared with corresponding normal or adjacent myometrium tissue. Here we reported that myocardin induced the transcription and expression of differentiation markers SM22α and alpha smooth muscle actin (α-SMA) in rat primary uterine smoothmore » muscle cells (USMCs) and this effect was inhibited by ERα. Notably, we showed that, ERα induced expression of proliferation markers PCNA and ki-67 in rat primary USMCs. We also found ERα interacted with myocardin and formed complex to bind to CArG box and inhibit the SM22α promoter activity. Furthermore, ERα inhibited the transcription and expression of myocardin, and reduced the levels of transcription and expression of downstream target SM22α, a SMC differentiation marker. Our data thus provided important and novel insights into how ERα and myocardin interact to control the cell differentiation and proliferation of USMCs. Thus, it may provide potential therapeutic target for uterine fibroids.« less

Promoter characteristics of two cyp19 genes differentially expressed in the brain and ovary of teleost fish.

PubMed

Tchoudakova, A; Kishida, M; Wood, E; Callard, G V

2001-11-01

Teleost fish are characterized by exceptionally high levels of neural estrogen biosynthesis when compared with the brains of other vertebrates or to the ovaries of the same fish. Two P450arom mRNAs which derive from separate gene loci (cyp19a and cyp19b) are differentially expressed in brain (b>a) and ovary (a>b) and have a different developmental program (b>a) and estrogen upregulation (b only). A polymerase chain reaction (PCR)-based genomic walking strategy was used to isolate the 5'-flanking regions of the goldfish (Carassius auratus) cyp19 genes. Sequence analysis of the cyp19b gene approximately 1.8 kb upstream of the transcription start site revealed a TATA box at nucleotide (nt) -30, two estrogen responsive elements (EREs; nt -351 and -211) and a consensus binding site (NBRE) for nerve growth factor inducible-B protein (NGFI-B/Nur77) at -286, which includes another ERE half-site. Also present were a sequence at nt -399 (CCCTCCT) required for neural specificity of the zebrafish GATA-2 gene, and 16 copies of an SRY/SOX binding motif. The 5'-flanking region ( approximately 1.0 kb) of the cyp19a gene had TATA (nt -48) and CAAT (nt -71) boxes, a steroidogenic factor-1 (SF-1) binding site (nt -265), eight copies of the SRY/SOX motif, and two copies of a recognition site for binding the arylhydrocarbon receptor (AhR)/AhR nuclear translocator factor (ARNT) heterodimer. Both genes had elements previously identified in the brain specific exon I promoter of the mouse aromatase gene. Cyp19a- and -b/luciferase constructs showed basal promoter activity in aromatase-expressing rodent pituitary (GH3) cells, but differences (a>b) did not reflect expression in fish pituitary in vivo (b>a), implying a lack of appropriate cell factors. Consistent with the onset of cyp19b expression in zebrafish embryos, microinjection of a green fluorescent protein (GFP) reporter plasmid into fertilized eggs revealed labeling in neural tissues at 30-48 h post-fertilization (hpf), most prominently in retinal ganglion cells (RGC) and axon-like projections to the optic tectum. Expression of a cyp19a/GFP reporter was not detectable up to 72 hpf. Tandem analysis of cyp19a and cyp19b promoters in living zebrafish embryos can be a useful approach for identifying cis-elements and cellular factors involved in the correct tissue-specific, spatial, temporal and estrogen regulated expression of aromatase genes during CNS and gonadal development.

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

2017-05-01

With increased life expectancy, women will spend over three decades of life postmenopause. The menopausal transition increases susceptibility to metabolic diseases such as obesity, diabetes, cardiovascular disease, and cancer. Thus, it is more important than ever to develop effective hormonal treatment strategies to protect aging women. Understanding the role of estrogens, and their biological actions mediated by estrogen receptors (ERs), in the regulation of cardiometabolic health is of paramount importance to discover novel targeted therapeutics. In this brief review, we provide a detailed overview of the literature, from basic science findings to human clinical trial evidence, supporting a protective role of estrogens and their receptors, specifically ERα, in maintenance of cardiometabolic health. In so doing, we provide a concise mechanistic discussion of some of the major tissue-specific roles of estrogens signaling through ERα. Taken together, evidence suggests that targeted, perhaps receptor-specific, hormonal therapies can and should be used to optimize the health of women as they transition through menopause, while reducing the undesired complications that have limited the efficacy and use of traditional hormone replacement interventions. Copyright © 2017 Endocrine Society.

Developmental expression and estrogen responses of endocrine genes in juvenile yellow perch (Perca flavescens)

USDA-ARS?s Scientific Manuscript database

The present study examines the expression of growth-regulating genes (gh, prl, smtl and igf1b), the estrogen receptors (esr1 and esr2a) and aromatase (cyp19a1a) in developing yellow perch. To gain an initial understanding into the endocrine control of growth preceding and involved with sexual size d...

Sex Steroid Hormones Matter for Learning and Memory: Estrogenic Regulation of Hippocampal Function Inmale and Female Rodents

ERIC Educational Resources Information Center

Frick, Karyn M.; Kim, Jaekyoon; Tuscher, Jennifer J.; Fortress, Ashley M.

2015-01-01

Ample evidence has demonstrated that sex steroid hormones, such as the potent estrogen 17ß-estradiol (E[subscript 2]), affect hippocampal morphology, plasticity, and memory in male and female rodents. Yet relatively few investigators who work with male subjects consider the effects of these hormones on learning and memory. This review describes…

Role of estrogen receptors alpha, beta and GPER1/GPR30 in pancreatic beta-cells.

PubMed

Nadal, Angel; Alonso-Magdalena, Paloma; Soriano, Sergi; Ripoll, Cristina; Fuentes, Esther; Quesada, Ivan; Ropero, Ana Belen

2011-01-01

Estrogen receptors (ER) are emerging as important molecules involved in the adaptation of beta-cells to insulin resistance. The onset of type 2 diabetes is marked by insulin secretory dysfunction and decreased beta-cell mass. During pregnancy, puberty and obesity there is increased metabolic demand and insulin resistance is developed. This metabolic state increases the demand on beta-cells to augment insulin biosynthesis and release. In this respect, ERalpha is directly implicated in the E2-regulation of insulin content and secretion, while ERbeta is in the E2-potentiation of glucose-induced insulin release. Both receptors develop their actions within the physiological range of E2. In addition, the G protein-coupled estrogen receptor (GPER1/GPR30) seems to be implicated in the E2-regulation of stimulus-secretion coupling in the three cell types of the islet. The increased demand of insulin production for long time may lead to beta-cell stress and apoptosis. ERalpha, ERbeta and GPER1/GPR30 are involved in preventing beta-cell apoptosis, impeding the loss of critical beta-cell mass. Therefore, estrogen receptors may play an essential role in the adaptation of the pancreas to insulin resistant periods.

Bone mass regulation of leptin and postmenopausal osteoporosis with obesity.

PubMed

Legiran, Siswo; Brandi, Maria Luisa

2012-09-01

Leptin has been known to play a role in weight regulation through food intake and energy expenditure. Leptin also has an important role in bone metabolism. The role of leptin is determined by leptin receptors, either central or peripheral to the bones. We discuss the role of leptin on bone and molecular genetics of osteoporosis in postmenopausal obese women. The role of leptin in bone preserves bone mineral density (BMD) through increased OPG levels leading to bind RANKL, resulting in reducing osteoclast activity. The estrogen role on bone is also mediated by RANKL and OPG. In postmenopausal women who have estrogen deficiency, it increases the rate of RANKL, which increases osteoclastogenesis. Obese individuals who have a high level of leptin will be effected by bone protection. There are similarities in the mechanism between estrogen and leptin in influencing the process of bone remodeling. It may be considered that the role of estrogen can be replaced by leptin. Molecular genetic aspects that play a role in bone remodeling, such as leptin, leptin receptors, cytokines (e.g. RANK, RANKL, and OPG), require further study to be useful, especially regarding osteoporosis therapy based on genetic analysis.

Pregnancy Augments G Protein Estrogen Receptor (GPER) Induced Vasodilation in Rat Uterine Arteries via the Nitric Oxide - cGMP Signaling Pathway.

PubMed

Tropea, Teresa; De Francesco, Ernestina Marianna; Rigiracciolo, Damiano; Maggiolini, Marcello; Wareing, Mark; Osol, George; Mandalà, Maurizio

2015-01-01

The regulation of vascular tone in the uterine circulation is a key determinant of appropriate uteroplacental blood perfusion and successful pregnancy outcome. Estrogens, which increase in the maternal circulation throughout pregnancy, can exert acute vasodilatory actions. Recently a third estrogen receptor named GPER (G protein-coupled estrogen receptor) was identified and, although several studies have shown vasodilatory effects in several vascular beds, nothing is known about its role in the uterine vasculature. The aim of this study was to determine the function of GPER in uterine arteries mainly during pregnancy. Uterine arteries were isolated from nonpregnant and pregnant rats. Vessels were contracted with phenylephrine and then incubated with incremental doses (10-12-10-5 M) of the selective GPER agonist G1. G1 induced a dose-dependent vasodilation which was: 1) significantly increased in pregnancy, 2) endothelium-dependent, 3) primarily mediated by NO/cGMP pathway and 4) unaffected by BKca channel inhibition. This is the first study to show the potential importance of GPER signaling in reducing uterine vascular tone during pregnancy. GPER may therefore play a previously unrecognized role in the regulation of uteroplacental blood flow and normal fetus growth.

Sirtuin 3 (SIRT3) maintains bone homeostasis by regulating AMPK-PGC-1β axis in mice

PubMed Central

Huh, Jeong-Eun; Shin, Ji Hye; Jang, Eun Sun; Park, So Jeong; Park, Doo Ri; Ko, Ryeojin; Seo, Dong-Hyun; Kim, Han-Sung; Lee, Seoung Hoon; Choi, Yongwon; Kim, Hyun Seok; Lee, Soo Young

2016-01-01

The mitochondrial sirtuin 3 (SIRT3) is involved in suppressing the onset of multiple pathologies, including cardiovascular disease, fatty liver, age-related hearing loss, and breast cancer. But a physiological role of SIRT3 in bone metabolism is not known. Here we show that SIRT3 is a key regulatory molecule to maintain bone homeostasis. Mice deficient in SIRT3 exhibited severe osteopenia owing to increased numbers of osteoclasts. Osteoclast precursors from Sirt3−/− mice underwent increased osteoclastogenesis in response to receptor activator of nuclear factor-κB ligand (RANKL), an essential cytokine for osteoclast differentiation. SIRT3 expression from RANKL induction depended on the transcription coactivator PGC-1β (peroxisome proliferator-activated receptor-γ co-activator-1β) and the nuclear receptor ERRα (estrogen receptor-related receptor α), and that SIRT3 inhibited the differentiation by interfering with the RANKL-induced expression of PGC-1β. Thus an auto-regulatory feedback mechanism operates to induce its own inhibitor SIRT3 by PGC-1β. Moreover, Sirt3−/− osteoclast precursors reduced AMP-activated protein kinase (AMPK) phosphorylation through down-regulating the expression of AMPK. Our results suggest that a mitochondrial SIRT3 is an intrinsic inhibitor for RANKL-mediated osteoclastogenesis. PMID:26928655

A novel FOXA1/ESR1 interacting pathway: A study of Oncomine™ breast cancer microarrays

PubMed Central

Chaudhary, Sanjib; Krishna, B. Madhu; Mishra, Sandip K.

2017-01-01

Forkhead box protein A1 (FOXA1) is essential for the growth and differentiation of breast epithelium, and has a favorable outcome in breast cancer (BC). Elevated FOXA1 expression in BC also facilitates hormone responsiveness in estrogen receptor (ESR)-positive BC. However, the interaction between these two pathways is not fully understood. FOXA1 and GATA binding protein 3 (GATA3) along with ESR1 expression are responsible for maintaining a luminal phenotype, thus suggesting the existence of a strong association between them. The present study utilized the Oncomine™ microarray database to identify FOXA1:ESR1 and FOXA1:ESR1:GATA3 co-expression co-regulated genes. Oncomine™ analysis revealed 115 and 79 overlapping genes clusters in FOXA1:ESR1 and FOXA1:ESR1:GATA3 microarrays, respectively. Five ESR1 direct target genes [trefoil factor 1 (TFF1/PS2), B-cell lymphoma 2 (BCL2), seven in absentia homolog 2 (SIAH2), cellular myeloblastosis viral oncogene homolog (CMYB) and progesterone receptor (PGR)] were detected in the co-expression clusters. To further investigate the role of FOXA1 in ESR1-positive cells, MCF7 cells were transfected with a FOXA1 expression plasmid, and it was observed that the direct target genes of ESR1 (PS2, BCL2, SIAH2 and PGR) were significantly regulated upon transfection. Analysis of one of these target genes, PS2, revealed the presence of two FOXA1 binding sites in the vicinity of the estrogen response element (ERE), which was confirmed by binding assays. Under estrogen stimulation, FOXA1 protein was recruited to the FOXA1 site and could also bind to the ERE site (although in minimal amounts) in the PS2 promoter. Co-transfection of FOXA1/ESR1 expression plasmids demonstrated a significantly regulation of the target genes identified in the FOXA1/ESR1 multi-arrays compared with only FOXA1 transfection, which was suggestive of a synergistic effect of ESR1 and FOXA1 on the target genes. In summary, the present study identified novel FOXA1, ESR1 and GATA3 co-expressed genes that may be involved in breast tumorigenesis. PMID:28789340

A novel FOXA1/ESR1 interacting pathway: A study of Oncomine™ breast cancer microarrays.

PubMed

Chaudhary, Sanjib; Krishna, B Madhu; Mishra, Sandip K

2017-08-01

Forkhead box protein A1 (FOXA1) is essential for the growth and differentiation of breast epithelium, and has a favorable outcome in breast cancer (BC). Elevated FOXA1 expression in BC also facilitates hormone responsiveness in estrogen receptor ( ESR )-positive BC. However, the interaction between these two pathways is not fully understood. FOXA1 and GATA binding protein 3 ( GATA3 ) along with ESR1 expression are responsible for maintaining a luminal phenotype, thus suggesting the existence of a strong association between them. The present study utilized the Oncomine™ microarray database to identify FOXA1:ESR1 and FOXA1:ESR1:GATA3 co-expression co-regulated genes. Oncomine™ analysis revealed 115 and 79 overlapping genes clusters in FOXA1:ESR1 and FOXA1:ESR1:GATA3 microarrays, respectively. Five ESR1 direct target genes [trefoil factor 1 ( TFF1/PS2 ), B-cell lymphoma 2 ( BCL2 ), seven in absentia homolog 2 ( SIAH2 ), cellular myeloblastosis viral oncogene homolog ( CMYB ) and progesterone receptor ( PGR )] were detected in the co-expression clusters. To further investigate the role of FOXA1 in ESR1-positive cells, MCF7 cells were transfected with a FOXA1 expression plasmid, and it was observed that the direct target genes of ESR1 ( PS2, BCL2, SIAH2 and PGR ) were significantly regulated upon transfection. Analysis of one of these target genes, PS2 , revealed the presence of two FOXA1 binding sites in the vicinity of the estrogen response element (ERE), which was confirmed by binding assays. Under estrogen stimulation, FOXA1 protein was recruited to the FOXA1 site and could also bind to the ERE site (although in minimal amounts) in the PS2 promoter. Co-transfection of FOXA1 / ESR1 expression plasmids demonstrated a significantly regulation of the target genes identified in the FOXA1 / ESR1 multi-arrays compared with only FOXA1 transfection, which was suggestive of a synergistic effect of ESR1 and FOXA1 on the target genes. In summary, the present study identified novel FOXA1 , ESR1 and GATA 3 co-expressed genes that may be involved in breast tumorigenesis.