RESUMO
The estrogen receptor alpha (ERα) is a ligand-activated transcription factor whose activity is modulated by its interaction with multiple protein complexes. In this work, we have identified the protein interferon alpha inducible protein 27 (IFI27/ISG12) as a novel ERα-associated protein. IFI27/ISG12 transcription is regulated by interferon and estradiol and its overexpression is associated to reduced overall survival in ER+ breast cancer patients but its function in mammary gland tissue remains elusive. In this study we showed that overexpression of IFI27/ISG12 in breast cancer cells attenuates ERα transactivation activity and the expression of ERα-dependent genes. Our results demonstrated that IFI27/ISG12 overexpression in MCF-7 cells reduced their proliferation rate in 2-D and 3-D cell culture assays and impaired their ability to migrate in a wound-healing assay. We show that IFI27/ISG12 downregulation of ERα transactivation activity is mediated by its ability to facilitate the interaction between ERα and CRM1/XPO1 that mediates the nuclear export of large macromolecules to the cytoplasm. IFI27/ISG12 overexpression was shown to impair the estradiol-dependent proliferation and tamoxifen-induced apoptosis in breast cancer cells. Our results suggest that IFI27/ISG12 may be an important factor in regulating ERα activity in breast cancer cells by modifying its nuclear versus cytoplasmic protein levels. We propose that IFI27/ISG12 may be a potential target of future strategies to control the growth and proliferation of ERα-positive breast cancer tumors.
Assuntos
Neoplasias da Mama/metabolismo , Regulação para Baixo/fisiologia , Receptor alfa de Estrogênio/biossíntese , Carioferinas/biossíntese , Proteínas de Membrana/biossíntese , Receptores Citoplasmáticos e Nucleares/biossíntese , Ativação Transcricional/fisiologia , Neoplasias da Mama/genética , Bases de Dados Genéticas , Regulação para Baixo/efeitos dos fármacos , Estradiol/farmacologia , Receptor alfa de Estrogênio/antagonistas & inibidores , Receptor alfa de Estrogênio/genética , Feminino , Humanos , Carioferinas/genética , Células MCF-7 , Proteínas de Membrana/genética , Receptores Citoplasmáticos e Nucleares/genética , Tamoxifeno/farmacologia , Ativação Transcricional/efeitos dos fármacos , Proteína Exportina 1RESUMO
Anti-Müllerian hormone (AMH) is secreted by Sertoli cells of the testes from early fetal life until puberty, when it is downregulated by androgens. In conditions like complete androgen insensitivity syndrome (CAIS), AMH downregulation does not occur and AMH increases at puberty, due in part to follicle-stimulating hormone (FSH) effect. However, other conditions like Peutz-Jeghers syndrome (PJS), characterised by low FSH, also have increased AMH. Because both CAIS and PJS may present as hyperoestrogenic states, we tested the hypothesis that oestradiol (E2) upregulates AMH expression in peripubertal Sertoli cells and explored the molecular mechanisms potentially involved. The results showed that E2 is capable of inducing an upregulation of endogenous AMH and of the AMH promoter activity in the prepubertal Sertoli cell line SMAT1, signalling through ERα binding to a specific ERE sequence present on the hAMH promoter. A modest action was also mediated through the membrane oestrogen receptor GPER. Additionally, the existence of ERα expression in Sertoli cells in patients with CAIS was confirmed by immunohistochemistry. The evidence presented here provides biological plausibility to the hypothesis that testicular AMH production increases in clinical conditions in response to elevated oestrogen levels.
Assuntos
Síndrome de Resistência a Andrógenos/metabolismo , Hormônio Antimülleriano/metabolismo , Receptor alfa de Estrogênio/biossíntese , Proteínas de Neoplasias/biossíntese , Síndrome de Peutz-Jeghers/metabolismo , Elementos de Resposta , Células de Sertoli/metabolismo , Síndrome de Resistência a Andrógenos/patologia , Animais , Linhagem Celular , Criança , Pré-Escolar , Estradiol/metabolismo , Feminino , Humanos , Masculino , Camundongos , Síndrome de Peutz-Jeghers/patologia , Células de Sertoli/patologiaRESUMO
The periaqueductal gray matter (PAG) is a brainstem site involved in distinct autonomic and behavioral responses. Among them, the motor control of female sexual behavior, including lordosis, is well described. Lordosis reflex is highly dependent on increasing levels of estradiol that occur in the afternoon of the proestrus day in normally cycling females. This effect is thought to be mediated primarily via actions in the ventromedial nucleus of the hypothalamus (VMH). By binding to estrogen receptor α (ERα), estradiol changes the activity of VMH neurons that project to the PAG. Evidence also exists for the coordination of PAG outputs by estradiol-responsive neurons outside the VMH. However, a comprehensive analysis of these circuitries is not available. Using stereotaxic injection of the retrograde tracer Fluorogold in distinct columns of the PAG we performed a systematic mapping of neurons innervating the PAG and those coexpressing ERα immunoreactivity. We found that the forebrain projections to PAG columns are largely segregated and that most of the ERα expressing neurons preferentially target the lateral and the ventrolateral columns. Dual labeled neurons were mostly found in the intermediate subdivision of the lateral septal nucleus, the posterior aspect of the medial bed nucleus of the stria terminalis, the medial preoptic nucleus, the striohypothalamic nucleus and the ventrolateral VMH. Few dual labeled neurons were also observed in the arcuate nucleus, in the posterodorsal subdivision of the medial nucleus of the amygdala and in the ventral premammillary nucleus. Our findings indicate that ERα modulates sexual behavior in female rats via an integrated neural network that differentially innervate the columns of the PAG.
Assuntos
Receptor alfa de Estrogênio/biossíntese , Vias Neurais/citologia , Neurônios/citologia , Substância Cinzenta Periaquedutal/citologia , Animais , Feminino , Neurônios/metabolismo , Ratos , Ratos Wistar , Comportamento Sexual Animal/fisiologiaRESUMO
BACKGROUND: Chronic inflammation has been implicated in cancer etiology and angiogenesis is stimulated in this disease. In prostate, the crosstalk between malignant epithelial cells and their microenvironment is an essential step of tumorigenesis during which glandular stroma undergo changes designated as reactive stroma. Thus, the aim herewith was to evaluate the effects of associating anti-inflammatory and antiangiogenic therapies on cancer progression, correlating them with steroid hormone receptor (AR and ERα), reactive stroma (vimentin, αSMA, and TGF-ß), and cell proliferation (PCNA) markers expression in the Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) model. METHODS: TRAMP mice (12-week old) were divided into the groups: Control (TRCON): received the vehicles used for drug dilution; Celecoxib (TRCEL): received oral doses of the anti-inflammatory drug celecoxib (15 mg/kg) twice daily; Nintedanib (TRNTB): received oral doses of the antiangiogenic drug nintedanib (10 mg/kg) daily; Nintedanib+Celecoxib (TRNTCEL): received the combination of drugs. After 6 weeks, mice were euthanized and ventral prostate samples were harvested for morphological, immunohistochemical, and Western blotting analyses. RESULTS: While celecoxib led to fibromuscular hypertrophy attenuation, nintedanib significantly reduced the incidence of well-differentiated adenocarcinoma (WDAC) foci in relation to controls, both when administered per se or in association to celecoxib. Furthermore, drug combination was associated with unique effects, including lower incidence of HGPIN lesions; lower AR stromal distribution; changes in ERα localization from epithelial nuclei to stroma as well as significant decrease of TGF-ß levels and associated angiogenesis. In parallel, all treatments applied resulted in reduced inflammatory marker and vimentin (VIM) expression. CONCLUSIONS: Celecoxib plus nintedanib is an effective antitumor combination against prostate cancer progression in TRAMP mice, showing remarkable efficacy in relation to isolated therapies. Importantly, this efficacy might be due to drug association effect on driving AR and mainly ERα distribution in the prostatic tissue towards benign patterns. In addition, celecoxib and nintedanib impaired the development of a stromal reaction by reducing the recruitment of reactive stroma cells and maintaining a normal smooth muscle cell-rich prostate stroma in TRAMP mice. Collectively, these findings pointed to the beneficial effects of combining anti-inflammatory and antiangiogenic strategies to prevent or delay prostatic tumorigenesis.
Assuntos
Inibidores da Angiogênese/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Próstata/efeitos dos fármacos , Neoplasias da Próstata/prevenção & controle , Animais , Celecoxib/farmacologia , Progressão da Doença , Sinergismo Farmacológico , Quimioterapia Combinada , Receptor alfa de Estrogênio/biossíntese , Indóis/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Lesões Pré-Cancerosas/tratamento farmacológico , Lesões Pré-Cancerosas/patologia , Próstata/irrigação sanguínea , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/irrigação sanguínea , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Receptores Androgênicos/biossíntese , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo , Células Estromais/patologiaRESUMO
INTRODUCTION: 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 ERß), altered ERα/ERß ratio may constitute a marker of ovarian carcinogenesis progression. OBJECTIVE: To determine the effect of estradiol through ERα on the expression of NGF and VEGF in epithelial ovarian cancer (EOC). METHODOLOGY: 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, ERß 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. RESULTS: 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 ERß levels did not change. Cell lines stimulated with estradiol revealed an increase of NGF and VEGF protein levels (p<0.05). CONCLUSIONS: 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.
Assuntos
Estradiol/farmacologia , Neoplasias Epiteliais e Glandulares/patologia , Fator de Crescimento Neural/biossíntese , Neoplasias Ovarianas/patologia , Fator A de Crescimento do Endotélio Vascular/biossíntese , Carcinoma Epitelial do Ovário , Receptor alfa de Estrogênio/biossíntese , Feminino , Humanos , Neoplasias Epiteliais e Glandulares/metabolismo , Fator de Crescimento Neural/efeitos dos fármacos , Neoplasias Ovarianas/metabolismoRESUMO
Telomerase plays a critical role in cell proliferation and senescence, but the exact involvement of endometrial telomerase in recurrent implantation failure (RIF) is unknown. We collected endometrial biopsies from RIF patients (N = 30) and fertile women (N = 30). Real-time PCR was performed for detecting changes in telomerase reverse transcriptase (Tert), ER alpha, and PR expression at the transcript level, and the correlation between the variable expressions of these genes was tested using regression analysis. Then, western blot and immunohistochemistry were used to analyze the expression profiles of TERT and ER alpha at the protein level. Compared to the control, Tert expression was substantially increased, whereas ER alpha expression significantly decreased in the endometrium with RIF. No change was observed in PR expression. Tert expression was inversely associated with ER alpha expression. TERT protein expression in RIF patients was also clearly elevated, and was localized to both the endometrial epithelium and stromal cells. However, the signals for ER alpha in the stromal cells were weaker than those in the control. Expression of endometrial telomerase was substantially enhanced as ER alpha decreased in RIF patients during the implantation window.
Assuntos
Implantação do Embrião/genética , Receptor alfa de Estrogênio/biossíntese , Receptores de Progesterona/genética , Telomerase/biossíntese , Adulto , Proliferação de Células/genética , Endométrio/patologia , Receptor alfa de Estrogênio/genética , Feminino , Regulação da Expressão Gênica , Humanos , Receptores de Progesterona/biossíntese , Células Estromais/metabolismo , Células Estromais/patologia , Telomerase/genéticaRESUMO
The aim of this study was to identify the expression, cellular localization and regulation of classic estrogen receptors ERα and ERß, ER-α36 isoform and GPER in the androgen-independent prostate cancer cell line PC-3. In addition, we evaluated the relative contribution of these receptors to the activation of the ERK1/2 (extracellular signal-regulated protein kinases) signaling pathway. These four estrogen receptors were detected by Western blot assays and were shown by immunofluorescence assays to localize preferentially in extranuclear regions of PC-3 cells. In addition, treatment with 17ß-estradiol (E2) (1 µM) for 24 h led to down-regulation of the classic estrogen receptors, whereas E2 at physiological concentration (0.1 nM) for 24h tended to increase the levels of ERα and ERß. Furthermore, the ERα-selective agonist PPT selectively increased the expression of ERß and the ERß-selective agonist DPN increased ERα levels. None of these treatments affected expression of the ER-α36 isoform. The unusual cytoplasmic localization of the classic estrogen receptors in these cells differs from the nuclear localization in the majority of estrogen target cells and suggests that rapid signaling pathways may be preferentially activated. In fact, treatment with selective agonists of ERα, ERß and GPER induced ERK1/2 phosphorylation that was blocked by the respective antagonists. On the other hand, activation of ERK1/2 induced by E2 may involve additional mechanisms because it was not blocked by the three antagonists. Taken together, the results indicate that there is a crosstalk between ERα and ERß to regulate the expression of each other, and suggest the involvement of other receptors, such as ER-α36, in the rapid ERK1/2 activation by E2. The identification of new isoforms of ERs, regulation of the receptors and signaling pathways is important to develop new therapeutic strategies for the castration-resistant prostate cancer.
Assuntos
Estradiol/farmacologia , Receptor alfa de Estrogênio/biossíntese , Receptor beta de Estrogênio/biossíntese , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Proteínas de Neoplasias/biossíntese , Neoplasias da Próstata/metabolismo , Linhagem Celular Tumoral , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Masculino , Proteínas de Neoplasias/genética , Neoplasias da Próstata/genéticaRESUMO
BACKGROUND AND RATIONALE: The control of Endothelin-1 (ET-1)-mediated intrahepatic vasoconstriction in cirrhosis is beneficial for the alleviation of relevant complications. Cirrhosis is accompanied by hypogonadism and altered sex hormone status. Besides, sex hormones have vasoactive effects, but it is unknown if they influence vascular function in cirrhosis. This study aimed to investigate the roles of sex hormones in hepatic vascular reactions to ET-1 in cirrhosis. Liver cirrhosis was induced in Spraque-Dawley male and female rats with common bile duct ligation (BDL). Sham-operated (Sham) rats were controls. On the 43rd day after operations, intrahepatic vascular concentration-response curves to ET-1 were obtained with the following preincubatioins: 1) vehicle; 2) 17ß-estradiol; 3) progesterone; 4) testosterone. Livers from sham and BDL rats were dissected for real-time polymerase chain reaction analysis of estrogen, progesterone and testosterone receptors. RESULTS: Compared with sham males perfused with vehicle, sham females presented higher perfusion pressure changes to ET-1 which was reversed only by 17 ß-estradiol. In cirrhosis, compared with males, 17 ß-estradiol no longer attenuated vascular responsiveness to ET-1 in females. In females, BDL rats had lower hepatic estrogen receptor α(ERßα) mRNA expression than that in sham rats. CONCLUSIONS: The sham females showed a stronger intrahepatic vascular constrictive effect to ET-1 than sham males, which could be reversed by 17ß-estradiol. However, the influence of 17 ß-estradiol was lost in cirrhotic females, which may be attributed, at least partly, to intrahepatic ER α down-regulation in females with cirrhosis.
Assuntos
Endotelina-1/farmacologia , Estradiol/farmacologia , Receptor alfa de Estrogênio/genética , Regulação da Expressão Gênica , Artéria Hepática/fisiopatologia , Cirrose Hepática Experimental/fisiopatologia , Vasoconstrição/efeitos dos fármacos , Animais , Receptor alfa de Estrogênio/biossíntese , Estrogênios/farmacologia , Feminino , Artéria Hepática/efeitos dos fármacos , Fígado/irrigação sanguínea , Fígado/metabolismo , Cirrose Hepática Experimental/tratamento farmacológico , Cirrose Hepática Experimental/genética , Masculino , RNA/genética , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo RealAssuntos
Apolipoproteína B-100/biossíntese , Doença da Artéria Coronariana/metabolismo , Receptor alfa de Estrogênio/biossíntese , Cardiopatias Congênitas/metabolismo , Túnica Íntima/metabolismo , Criança , Pré-Escolar , Doença da Artéria Coronariana/patologia , Feminino , Regulação da Expressão Gênica , Cardiopatias Congênitas/patologia , Humanos , Hiperplasia/metabolismo , Hiperplasia/patologia , Lactente , Recém-Nascido , Masculino , Túnica Íntima/patologiaRESUMO
BACKGROUND: Intragastric or intraperitoneal ethanol (EtOH) treatment inhibits reproductive functions in females and male rats. The area of the hypothalamus where these effects take place is unknown. As the participations of the preoptic-anterior hypothalamic area (POA-AHA) in regulating ovulation is asymmetric, this study aims to analyze the effects on 17ß-estradiol(E2 ), progesterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) serum levels, the messenger ribonucleic acid (mRNA) expression of estrogen receptor alpha (ERα) and beta (ERß), and ovulation resulting from unilaterally microinjecting water or an EtOH solution into either side of the POA-AHA. METHODS: The treatment consisted of microinjecting a 8.6 µM EtOH solution into either side of the POA-AHA. The study was performed on groups of adult cyclic rats at 09.00 hours on diestrus-1, and sacrificed on diestrus-2 at 13.00, on proestrus at 09.00 or 17.00 or on estrus at 09.00 hours. Ovulation rates were assessed in rats sacrificed on estrus. Hormonal serum levels were measured using radioimmunoassay, and as a function of ERα and ERß mRNA expression in each side of the POA-AHA by reverse transcriptase polymerase chain reaction. RESULTS: EtOH treatment blocked ovulation and the preovulatory release of LH, and lowered E2 levels. Irrespective of the treated POA-AHA side, ERα mRNA expression was consistently lower in the left POA-AHA and higher on the right. EtOH treatment in the left POA-AHA decreased FSH serum levels and lowered ERß mRNA expression. In turn, EtOH treatment on the right POA-AHA resulted in higher FSH levels and ERß mRNA expression. CONCLUSIONS: The present results show that EtOH blocks the preovulatory surge of LH on the POA-AHA. The effects of EtOH treatment of preovulatory FSH surge on the POA-AHA are asymmetric (stimulative on the right and inhibiting in the left). The effects of EtOH treatment on preovulatory LH and FSH surge could be explained by the inhibition of ERα and ERß mRNA expression, respectively.
Assuntos
Núcleo Hipotalâmico Anterior/efeitos dos fármacos , Etanol/farmacologia , Ovulação/efeitos dos fármacos , Área Pré-Óptica/efeitos dos fármacos , Animais , Núcleo Hipotalâmico Anterior/fisiologia , Estradiol/sangue , Receptor alfa de Estrogênio/biossíntese , Receptor beta de Estrogênio/biossíntese , Etanol/administração & dosagem , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Microinjeções , Área Pré-Óptica/fisiologia , Progesterona/sangue , Ratos , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Estrogen regulates reproductive behavior and drives the proliferation and differentiation of several cell types. These physiological functions of estrogen are mediated by estrogen receptors (ERs), and each ER isoform plays a distinct role. To clarify the molecular mechanism of estrogen action and to evaluate the effect of ERs on the secretion of ovalbumin (OVA) in pigeon oviduct epithelial cells (POECs), we determined the complete coding sequences encoding ER alpha (ERα) and ER beta (ERß) in pigeons. The abundance of pigeon ERα and ERß mRNA was detected using quantitative polymerase chain reaction. These results revealed that pigeon ERα is highly expressed in the oviduct, while pigeon ERb is highly expressed in the ovary and kidney. We hypothesize that ERα mRNA predominates over that of ERß in the oviduct. The expression of ERα can be down-regulated by 17ß-estradiol, and the knockdown of ERα promoted OVA mRNA expression in cultured POECs, indicating that ERα may play an important role in OVA secretion.
Assuntos
Células Epiteliais/metabolismo , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Animais , Clonagem Molecular , Columbidae/genética , Estradiol/metabolismo , Receptor alfa de Estrogênio/biossíntese , Receptor beta de Estrogênio/biossíntese , Feminino , Expressão Gênica , Oviductos/metabolismo , RNA Mensageiro/biossínteseRESUMO
OBJECTIVES: To analyze the expression of protein markers related to cell proliferation and death, as well as oestrogen and progesterone receptors in the endometrium of infertile women with hypothalamic-pituitary dysfunction treated with clomiphene citrate (CC) or recombinant follicle-stimulating hormone (rFSH), and compare them with ovulatory women. STUDY DESIGN: The study included 12 control ovulatory women and 29 anovulatory women, 19 of whom underwent ovulation induction with CC (n = 12) or rFSH (n = 5). Endometrial biopsies were obtained by Pipelle during the mid-secretory phase. Samples were stained with haematoxylin and eosin. Immunohistochemistry of proteins related to cell proliferation and cell death, as well as steroid receptors, was undertaken, and apoptosis was determined using TUNEL analysis. RESULTS: Immunohistochemical analysis of Ki67 expression showed significantly higher expression in the glandular epithelium of ovulatory women compared with the other groups. Glandular oestrogen receptor α expression was significantly lower in rFSH-treated women compared with ovulatory women. The number of apoptotic cells, Bax expression and progesterone receptor expression were similar in all groups. In contrast, Bcl-2 expression was significantly lower in the glandular epithelium of rFSH-treated women. CONCLUSIONS: In infertile women with hypothalamic-pituitary dysfunction, treatment with ovulation-inducing agents modifies the expression of proteins involved in cell proliferation and death, as well as the expression of steroid hormone receptors in the endometrium. These differences may help to explain, at the molecular level, the functionality of the endometrium during the implantation window, and may help to optimize pregnancy rates obtained with these treatments.
Assuntos
Clomifeno/uso terapêutico , Endométrio/metabolismo , Fármacos para a Fertilidade Feminina/uso terapêutico , Hormônio Foliculoestimulante/uso terapêutico , Infertilidade Feminina/metabolismo , Adulto , Morte Celular/fisiologia , Proliferação de Células , Receptor alfa de Estrogênio/biossíntese , Feminino , Humanos , Infertilidade Feminina/tratamento farmacológico , Fase Luteal/fisiologia , Indução da Ovulação , Receptores de Progesterona/biossíntese , Proteína X Associada a bcl-2/biossínteseRESUMO
OBJECTIVE: To determine changes in morphometry and expression of oestrogen receptors (OR) in the pubococcygeus and bulbospongiosus muscles, and the concentration of serum oestradiol associated with multiparity. STUDY DESIGN: Twelve chinchilla-breed female rabbits were divided into multiparas who had undergone four consecutive deliveries and age-matched virgin nulliparas. Pubococcygeus and bulbospongiosus muscles were surgically removed from each rabbit and processed histologically. Fibre cross-sectional area, number of peripheral nuclei, and expression of ORα and ORß were measured for each muscle. Serum samples were obtained and the concentration of serum oestradiol was quantified. RESULTS: Multiparity increased (p ≤ 0.05) fibre cross-sectional area and the number of peripheral nuclei per fibre in pubococcygeus muscle, but not in bulbospongiosus muscle. Expression of both ORα and ORß was high (p ≤ 0.05) in both muscles from multiparous rabbits. A rise in serum oestradiol was measured at the end of the second pregnancy, which was absent (p ≤ 0.05) at the end of the fourth pregnancy. The concentration of serum oestradiol was similar (p > 0.05) in nulliparous and multiparous rabbits. CONCLUSIONS: Multiparity caused morphometric changes in pubococcygeus muscle but not in bulbospongiosus muscle. As OR expression was high for both muscles, some properties related to fibre composition or muscle physiology could be affected. The finding that serum oestradiol was not elevated at the end of the fourth pregnancy could be related to changes in pelvic and perineal muscles associated with multiparity.
Assuntos
Estradiol/sangue , Receptor alfa de Estrogênio/biossíntese , Receptor beta de Estrogênio/biossíntese , Músculo Esquelético/fisiologia , Paridade/fisiologia , Prenhez/fisiologia , Animais , Feminino , Fibras Musculares Esqueléticas/ultraestrutura , Músculo Esquelético/ultraestrutura , Gravidez , CoelhosRESUMO
In mammals, estrogens have been described as endocrine and paracrine modulators of neuronal differentiation and synapse formation. However, the functional role of circulating estrogens and the distribution of estrogen receptors (ERs) in the cerebral cortex of reptiles have not been clearly established. Caiman latirostris (C. latirostris) is a South American species that presents temperature-dependent sex determination (TSD). By using immunohistochemistry, we have studied the distribution of ERα in the cerebral cortex of neonatal caimans. We studied brain samples from ten-day-old TSD-females and TSD-males and from female caimans that were administered estradiol during embryonic development (hormone-dependent sex determination, HSD-females). ERα was detected in the medial (MC), dorsal (DC) and lateral (LC) cortices. ERα expression in the MC showed sex-associated differences, being significantly greater in TSD-females compared to TSD-males. Interestingly, the highest ERα expression in the MC was exhibited by HSD-females. In addition, the circulating levels of estradiol were significantly higher in females (both TSD and HSD) than in TSD-males. Double immunostaining showed that ERα is expressed by neural precursor cells (as detected by ERα/doublecortin or ERα/glial fibrillary acidic protein) and mature neurons (ERα/neuron-specific nuclear protein). Our results demonstrate that the expression of ERα in the neonatal caiman cortex is sexually dimorphic and is present in the early stages of neuronal differentiation.
Assuntos
Jacarés e Crocodilos/metabolismo , Córtex Cerebral/metabolismo , Receptor alfa de Estrogênio/biossíntese , Processos de Determinação Sexual/efeitos dos fármacos , Jacarés e Crocodilos/embriologia , Animais , Diferenciação Celular , Córtex Cerebral/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Estradiol/sangue , Estradiol/farmacologia , Receptor alfa de Estrogênio/efeitos dos fármacos , Feminino , Masculino , Neurônios/citologia , Neurônios/fisiologia , Caracteres Sexuais , TemperaturaRESUMO
Thyrotropin receptor (TSH-R), thyroglobulin (Tg), thyroperoxidase (TPO), thyroid specific transcription factor-1 (TTF-1), paired box 8 transcription factor (PAX-8), insulin like growth factor-1 (IGF-1) and estrogen receptor alpha (ERα) transcripts were determined by real-time PCR in follicular carcinoma and contralateral (CL) lobes, and healthy thyroid canine glands. Concentrations of TSH-R, PAX-8, and ERα mRNA were not different among groups; the carcinoma group had lower Tg and TPO mRNA than healthy and CL groups, while no differences were found between the two latter groups, suggesting that the carcinoma tissue presents an altered capacity to synthesize thyroid hormones. The transcription factor that promotes thyrocytes proliferation, TTF-1 as well as IGF-1, presented a greater mRNA expression in the CL group, suggesting that the CL lobe may function in a compensatory state.
Assuntos
Doenças do Cão/metabolismo , Receptor alfa de Estrogênio/biossíntese , Fator de Crescimento Insulin-Like I/biossíntese , Iodeto Peroxidase/biossíntese , Proteínas Nucleares/biossíntese , Fatores de Transcrição Box Pareados/biossíntese , Receptores da Tireotropina/biossíntese , Tireoglobulina/biossíntese , Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/metabolismo , Fatores de Transcrição/metabolismo , Animais , Cães , Feminino , Masculino , Fator de Transcrição PAX8 , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Fator Nuclear 1 de Tireoide , Fatores de Transcrição/biossínteseRESUMO
Prenatal exposure to BPA disturbs mammary gland histoarchitecture and increases the carcinogenic susceptibility to chemical challenges administered long after BPA exposure. Our aim was to assess the effect of prenatal BPA exposure on mammary gland angiogenesis and steroid hormone pathways in virgin cycling rats. Pregnant Wistar rats were exposed to either 25 or 250 g/kg/day (25 and 250 BPA, respectively) or to vehicle. Female offspring were autopsied on postnatal day (PND) 50 or 110. Ovarian steroid serum levels, the expression of steroid receptors and their co-regulators SRC-3 and SMRT in the mammary gland, and angiogenesis were evaluated. At PND 50, all BPA-treated animals had lower serum levels of progesterone, while estradiol levels remained unchanged. The higher dose of BPA increased mammary ERα and decreased SRC-3 expression at PND 50 and PND 110. SMRT protein levels were similar among groups at PND 50, whereas at PND 110, animals exposed to 250 BPA showed a lower SMRT expression. Interestingly, in the control and 25 BPA groups, SMRT increased from PND 50 to PND 110. At PND 50, an increased vascular area associated with higher VEGF expression was observed in the 250 BPA-treated rats. At PND 110, the vascular area was still increased, but VEGF expression was similar to that of control rats. The present results demonstrate that prenatal exposure to BPA alters the endocrine environment of the mammary gland and its angiogenic process. Increased angiogenesis and altered steroid hormone signals could explain the higher frequency of pre-neoplastic lesions found later in life. This article is part of a Special Issue entitled 'Endocrine disruptors'.
Assuntos
Disruptores Endócrinos/efeitos adversos , Glândulas Mamárias Animais/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Fenóis/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Animais , Compostos Benzidrílicos , Estradiol/sangue , Receptor alfa de Estrogênio/biossíntese , Feminino , Glândulas Mamárias Animais/irrigação sanguínea , Glândulas Mamárias Animais/patologia , Gravidez , Progesterona/sangue , Ratos , Ratos Wistar , Proteínas Adaptadoras da Sinalização Shc/biossíntese , Proteína 3 de Transformação que Contém Domínio 2 de Homologia de SrcRESUMO
Multicellular spheroids are excellent models for the analysis of cancer behavior. Just like small avascular tumors, they present a marked zonal heterogeneity which influences gene expression and thus, growth and response to chemotherapy. In the present paper, we sought to analyze the effects of three-dimensional culture in the expression and distribution of estrogen receptor alpha. Using MCF-7 breast cancer cells, we found that multicellular spheroids in estrogen-containing medium presented a paradoxical regulation of estrogen receptor alpha, with a decrease in protein expression and a marked increase in mRNA steady-state levels. Immunohistochemistry showed that only sparse cells in the periphery of the spheroid expressed estrogen receptor, in sharp contrast with progesterone receptor, which was more extensively expressed and HIF-alpha, which was expressed in the central core of the spheroid. This could mean that both hypoxia and ERA activation by estrogen participate in the expression heterogeneity of this hormone receptor in breast cancer These results are important to considerate in the analysis and interpretation of immunohistochemistry of ERA and downstream targets in samples of solid tumors.
Assuntos
Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/biossíntese , Esferoides Celulares/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , RNA Mensageiro/metabolismo , Receptores de Progesterona/biossínteseRESUMO
The aim of the present study was to investigate the effects of 17beta-estradiol on expression of muscarinic acetylcholine receptor subtypes (M1 to M5) and estrogen receptor alpha, in the rat hippocampus. Hippocampi were obtained from rats in proestrus, rats ovariectomized for 15 days, rats ovariectomized for 15 days and then treated with 17beta-estradiol for 7 days, and rats ovariectomized and immediately treated with 17beta-estradiol for 21 days. Expression of M1 to M5 was increased in hippocampi of rats ovariectomized for 15 days compared to rats in proestrus. Although this effect was abolished when replacement with 17beta-estradiol started immediately after ovariectomy, the increased expression of M1, M3 and M5 receptor subtypes was unchanged when replacement with 17beta-estradiol started only 15 days after ovariectomy. The expression of estrogen receptor alpha in the hippocampus was also upregulated after ovariectomy when compared to rats in proestrus. This effect was abolished when 17beta-estradiol was replaced immediately after ovariectomy, and slightly reduced when the replacement started 15 days after ovariectomy. The replacement with estrogen also had beneficial effects on cognitive function, as suggested by data obtained in the plus-maze discriminative avoidance task. In conclusion, the present results provide evidence that 17beta-estradiol regulates the expression of muscarinic acetylcholine receptor subtypes and estrogen receptor alpha. The immediate replacement with estrogen seems critical to restore the expression of these receptors after hormonal deprivation. The understanding of the regulation of expression and intracellular signaling of the muscarinic acetylcholine receptor subtype M1 and the estrogen receptor alpha may be helpful to elucidate the mechanisms involved in changes of cognitive function in postmenopausal women and in neurodegenerative diseases.
Assuntos
Estradiol/farmacologia , Receptor alfa de Estrogênio/biossíntese , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/metabolismo , Subunidades Proteicas/biossíntese , Receptores Muscarínicos/biossíntese , Animais , Feminino , Hipocampo/efeitos dos fármacos , Ovariectomia , Ratos , Ratos Wistar , Receptores Muscarínicos/classificaçãoRESUMO
BACKGROUND: CXCL12 is a chemokine that is constitutively expressed in many organs and tissues. CXCL12 promoter hypermethylation has been detected in primary breast tumours and contributes to their metastatic potential. It has been shown that the oestrogen receptor alpha (ESR1) gene can also be silenced by DNA methylation. In this study, we used methylation-specific PCR (MSP) to analyse the methylation status in two regions of the CXCL12 promoter and ESR1 in tumour cell lines and in primary breast tumour samples, and correlated our results with clinicopathological data. METHODS: First, we analysed CXCL12 expression in breast tumour cell lines by RT-PCR. We also used 5-aza-2'-deoxycytidine (5-aza-CdR) treatment and DNA bisulphite sequencing to study the promoter methylation for a specific region of CXCL12 in breast tumour cell lines. We evaluated CXCL12 and ESR1 methylation in primary tumour samples by methylation-specific PCR (MSP). Finally, promoter hypermethylation of these genes was analysed using Fisher's exact test and correlated with clinicopathological data using the Chi square test, Kaplan-Meier survival analysis and Cox regression analysis. RESULTS: CXCL12 promoter hypermethylation in the first region (island 2) and second region (island 4) was correlated with lack of expression of the gene in tumour cell lines. In the primary tumours, island 2 was hypermethylated in 14.5% of the samples and island 4 was hypermethylated in 54% of the samples. The ESR1 promoter was hypermethylated in 41% of breast tumour samples. In addition, the levels of ER alpha protein expression diminished with increased frequency of ESR1 methylation (p < 0.0001). This study also demonstrated that CXCL12 island 4 and ESR1 methylation occur simultaneously at a high frequency (p = 0.0220). CONCLUSIONS: This is the first study showing a simultaneous involvement of epigenetic regulation for both CXCL12 and ESR1 genes in Brazilian women. The methylation status of both genes was significantly correlated with histologically advanced disease, the presence of metastases and death. Therefore, the methylation pattern of these genes could be used as a molecular marker for the prediction of breast cancer outcome.
Assuntos
Neoplasias da Mama/genética , Quimiocina CXCL12/genética , Metilação de DNA , Receptor alfa de Estrogênio/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Quimiocina CXCL12/biossíntese , Ilhas de CpG , Análise Mutacional de DNA , Receptor alfa de Estrogênio/biossíntese , Feminino , Inativação Gênica , Predisposição Genética para Doença , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Prognóstico , Regiões Promotoras Genéticas , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Recently, the effects of extremely low-frequency electromagnetic fields (ELF EMF) on biological systems have been extensively investigated. In this report, the influence of ELF EMF on olfactory bulb (OB) estrogen receptor-alpha (ER alpha) mRNA and -beta (ER beta) mRNA expression was studied by RT-PCR in adult female and male rats. Results reveal for the first time that ELF EMF exerted a biphasic effect on female OB ER beta mRNA gene expression, which increased during diestrous and decreased during estrous. We did not observe any influence of ELF EMF on female OB ER alpha mRNA expression. Our data demonstrate a fluctuating pattern of ER-alpha and -beta mRNA expression in the female OB throughout the phases of the estrous cycle in non-ELF EMF-exposed animals. Thus the highest ER alpha expression was observed in diestrous and the lowest in proestrous. The pattern of ER beta mRNA was less variable, the lowest expression was observed in diestrous. ER-alpha mRNA and -beta mRNA expression level in the male OB did not exhibit any variation either in ELF EMF-exposed or non-ELF EMF-exposed animals. In summary, ELF EMF modulate ER beta gene expression in the OB of female adult rats but not in males.