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1.
Reproduction ; 153(6): 797-808, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28348070

RESUMO

Albeit devoid of intrinsic catalytic activity, the transmembrane heparan sulphate proteoglycan syndecan 1 plays critical roles in cellular processes such as extracellular matrix crosstalk, cytoskeletal organization, cell spreading, proliferation and differentiation. During the ovarian cycle, the expression of syndecan 1 in granulosa cells shows cyclic variation suggesting that it might fulfil specific roles in follicle development. To investigate its physiological roles on granulosa cells, syndecan 1 was overexpressed in human granulosa cell line KGN which retains features of granulosa cells from small antral follicle such as estradiol (E2) synthesis and low expression of functional FSH receptor (FSHR). We demonstrated that overexpression of syndecan 1 in immature granulosa cells (KGN-SDC1) induces a profound alteration in their intrinsic characteristics including enhanced spreading and attachment, both associated with a reduced growth rate. Flow cytometry analysis revealed that syndecan 1 overexpression increases the percentage of KGN cells in quiescent phase. This partial cell cycle exit is concordant with downregulated levels of CCND1 and CDK4 and upregulated expression of CDK inhibitor CDKN1A In parallel both unstimulated and FSH-induced E2 synthesis are reduced in KGN-SDC1 through both repression of CYP19A1 and FSHR mRNA associated with decreased levels of potential regulators NR5A1 and ESR2 Additionally, we provide evidence that transient cAMP accumulation reduction in cells overexpressing syndecan 1 is accompanied by an increase in cAMP-hydrolysing PDE activity. Our results demonstrated that syndecan 1 might regulate differentiation of granulosa cells and follicular development by means of various mechanisms involving morphological changes, control of signalling pathways and alterations in gene expressions.Free French abstract: A French translation of this abstract is freely available at http://www.reproduction-online.org/content/153/6/797/suppl/DC1.Reproduction.


Assuntos
Proliferação de Células/efeitos dos fármacos , Hormônio Foliculoestimulante/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Tumor de Células da Granulosa/patologia , Sindecana-1/metabolismo , Aromatase/metabolismo , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Feminino , Tumor de Células da Granulosa/tratamento farmacológico , Tumor de Células da Granulosa/metabolismo , Humanos , Pessoa de Meia-Idade , Receptores do FSH/metabolismo , Transdução de Sinais , Células Tumorais Cultivadas
2.
Basic Clin Androl ; 33(1): 35, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38082221

RESUMO

BACKGROUND: In 15-49 years-old men, the main cancers are testicular cancer (TC) and lymphomas (L): freezing of ejaculated sperm is primarily used for male fertility preservation (FP) before cancer treatment. Our objective was to analyze the French FP rate in 15-49 years-old men diagnosed with TC or L in 2018. We designed a national descriptive cross-sectional study of sperm banking rate in men with a diagnosis of TC, Hodgkin L (HL) or non-Hodgkin L (NHL). From the French National Cancer Institute (INCa) 2018 data, we extracted the estimated incidence of TC and L in metropolitan France. From the 2018 activity report of CECOS network (Centers for Study and Banking of Eggs and Sperm), we extracted the number of men with TC or L who banked ejaculated sperm. We estimated the proportion of 15-49 years-old men diagnosed with TC or L who banked sperm. RESULTS: Among 15-49 years-old men, INCa estimated 38,048 new cancer diagnoses in metropolitan France in 2018: 2,630 TC and 3,913 L (943 HL and 2,970 NHL). The CECOS network provided data from 26/27 metropolitan centers (96% response rate): 1,079 sperm banking for men with TC, 375 for HL and 211 for NHL. We estimated that the 2018 sperm banking rate in France was 41% for TC, 40% for HL, and 7% for NHL. CONCLUSIONS: To our knowledge, our paper is the first cross-sectional study with multicenter and national data analyzing FP rate in cancer men: it suggests an efficient pathway for men to FP before cancer treatment, compared to previously published studies. Although sperm banking rate in 15-49 years-old men could definitely be improved, further studies should evaluate the information given to patients before gonadotoxic treatments, the factors associated with the absence of sperm banking and whether this lack of referral induces a loss of chance for these men.


RéSUMé: CONTEXTE: Chez les hommes de 15 à 49 ans, les principaux cancers sont le cancer du testicule (CT) et les lymhomes (L): la congélation de spermatozoïdes éjaculés est utilisée en première intention pour leur préservation de fertilité (PF) avant traitement du cancer. Notre objectif était d'analyser le taux de PF chez les hommes de 15 à 49 ans diagnostiqués avec un CT ou un L en 2018 en France. Nous avons réalisé une étude nationale transversale descriptive du taux de congelation de spermatozoïdes chez les hommes âgés de 15 à 49 ans diagnostiqués avec un CT, un L de Hodgkin (LH) ou un L non-Hodgkinien (LNH). A partir des données de l'Institut National du Cancer (INCa) de 2018, nous avons extrait l'incidence estimée de CT et de L en France métropolitaine. A partir des données du bilan d'activité 2018 de la Federation Française des CECOS (Centre d'Etude et de Conservation des Oeufs et du Sperme), nous avons extrait le nombre d'hommes avec un CT ou un L qui ont congelé leurs spermatozoïdes. Nous avons enfin estimé la proportion d'hommes de 15 à 49 ans diagnostiqués avec un CT ou un L qui ont congelé leurs spermatozoïdes. RéSULTATS: Chez les hommes de 15 à 49 ans, l'INCa a estimé en 2018 38 048 nouveaux cas de cancers diagnostiqués en France métropolitaine en 2018: 2 630 CT et 3 913 L (943 LH et 2 970 LNH). Le réseau des CECOS a produit les résultats issus de 26/27 centres métropolitains (taux de réponse de 96%): 1 079 congélations de sperme pour des hommes atteints de CT, 375 pour LH et 211 pour LNH. Nous avons estimé que le taux de congelation de spermatozoïdes de 2018 en France était de 41% pour le CT, 40% pour le LH et 7% pour le LNH. CONCLUSIONS: A notre connaissance, notre travail est la première étude transversale multicentrique de données nationales analysant le taux de PF chez les hommes atteints de cancer: il suggère un parcours patient efficace pour la PF des hommes avant traitement d'un cancer, par rapport aux études précédemment publiées. Bien que le taux de PF chez les hommes puisse certainemen être amélioré, des études futures devraient évaluer l'information donnée aux patients avant traitement gonadotoxique, les facteurs associés à l'absence de PF et si le défaut d'adressage au CECOS induit un perte de chance pour ces hommes. MOTS-CLéS: Chimiothérapie, Radiothérapie, Oncofertiité, Azoospermia, Paternité.

3.
Reprod Biomed Online ; 21(1): 56-65, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20457540

RESUMO

Gonadotrophin-releasing hormone (GnRH) agonists and antagonists have been widely used to prevent premature LH surge during ovarian stimulation. However, studies have shown a significantly lower serum oestradiol concentration on the day of human chorionic gonadotrophin administration for cycles using GnRH antagonist. This study compared aromatase gene expression in granulosa lutein cells from 50 women randomly assigned to receive either GnRH agonist (group 1, n=28) or GnRH antagonist (group 2, n=22). The cellular mechanism involved in the observed effects was also investigated. GnRH antagonist treatment significantly affected serum oestradiol concentration (1894+/-138 versus 1074+/-63 pg/ml; P < or = 0.001), follicular-fluid oestradiol concentration in large follicles (18,565+/-2467 versus 10,184+/-1993 pg/ml; P < or = 0.05), aromatase activity (9600+/-1179 versus 5376+/-997 fmol/10(6) cells/h; P < or = 0.05) and mRNA aromatase/mRNA glyceraldehyde 3-phosphate dehydrogenase (15+/-3 versus 6+/-1; P < 0.05). Protein kinase C (PKC) activity in granulosa lutein cells from the GnRH antagonist group was 2.5-fold higher than in the GnRH agonist group. In-vitro experiments showed that selective down-regulation of PKC was only observed in GnRH-desensitized granulosa lutein cells. This report suggests that, in granulosa lutein cells, the modulation of the FSH-induced protein kinase A pathway by PKC was different in agonist versus antagonist cycles.


Assuntos
Hormônio Liberador de Gonadotropina/análogos & derivados , Hormônio Liberador de Gonadotropina/agonistas , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Indução da Ovulação/métodos , Pamoato de Triptorrelina/uso terapêutico , Adulto , Aromatase/biossíntese , Aromatase/genética , Regulação para Baixo , Estradiol/sangue , Feminino , Líquido Folicular/metabolismo , Hormônio Liberador de Gonadotropina/uso terapêutico , Células da Granulosa/efeitos dos fármacos , Células da Granulosa/metabolismo , Humanos , Folículo Ovariano/metabolismo , Gravidez , Taxa de Gravidez , Proteína Quinase C/metabolismo
4.
Eur J Obstet Gynecol Reprod Biol ; 238: 73-77, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31121341

RESUMO

INTRODUCTION: Turner syndrome is one of the most frequent chromosomal abnormalities in women, with a prevalence estimated to be 1 of 2500 live birth. Pregnancy in women with Turner syndrome is known to be at high risk, whether it is spontaneous or after oocyte donation, because of miscarriages and potential cardio-vascular complications which can be life-threatening. All of these patients should therefore be screened with a comprehensive cardio-vascular assessment before pregnancy, and have a close follow-up during and after pregnancy. PATIENTS AND METHODS: It is a retrospective study, conducted in 10 of the 27 French oocyte donation centers between 2012 and 2016, on all the patients presenting with Turner syndrome included in an oocyte donation program. RESULTS: 151 embryo transfers were realized in 73 patients, resulting in 39 pregnancies. Among these pregnancies, 24 children were born healthy, 11 spontaneous miscarriages, 3 voluntary abortions, 1 extra-uterine pregnancy and 1 maternal death from non-cardio-vascular origin occurred. Pregnancies were complicated by gravid arterial hypertension in 28.2% of cases, preeclampsia in 10.3% of cases, and gestational diabetes in 7.7% of cases. CONCLUSION: This study bring out obstetrical complications of the same magnitude than the ones described in the literature. Lead over a period of 4 years, in 10 French oocyte donation centers, it doesn't reveal any cardio-vascular complications, conversely to other studies published before French and American recommendations. This study reinforces the usefulness of specific recommendations for the care of these particular patients.


Assuntos
Doação de Oócitos/estatística & dados numéricos , Complicações na Gravidez/etiologia , Síndrome de Turner/complicações , Adulto , Feminino , França/epidemiologia , Humanos , Gravidez , Complicações na Gravidez/epidemiologia , Estudos Retrospectivos
6.
Clin Endocrinol (Oxf) ; 68(5): 692-9, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-17980016

RESUMO

OBJECTIVE: Abnormal responsiveness to arginine vasopressin (AVP) was previously observed in cortisol-producing adrenocortical tumours but the mechanism remains unclear. The aim of this study was to characterize the effect of AVP on cortisol secretion from adrenocortical tumours compared to normal human adrenal gland. DESIGN: A multicentre study based on pharmacological, molecular and immunohistochemical experiments performed in adenomatous and normal adrenal tissues. PATIENTS: Twenty patients with adrenocortical adenomas and subclinical Cushing's syndrome (SCCS) or Cushing's syndrome (CS) were compared to six control normal subjects. MEASUREMENTS: In vivo and in vitro cortisol response to vasopressin, vasopressin receptor subtype mRNA measurement by real-time polymerase chain reaction (RT-PCR), immunohistochemical localization of AVP and its V1a receptor in tumour and normal adrenal tissues. RESULTS: Terlipressin in vivo enhanced cortisol plasma levels in 17/20 SCCS and 3/6 CS but in none of the control subjects. In vitro cortisol response to AVP was observed in nine tumours studied, with enhanced efficacy and/or potency of AVP in three SCCS tumours compared to normal tissues. AVP receptor subtype mRNA levels were similar in SCCS, CS cells and normal adrenal cells. Some SCCS tumour steroidogenic cells showed AVP and V1a receptor immunoreactivity. CONCLUSIONS: SCCS and CS adrenocortical tumours often exhibit in vivo and in vitro hyper-responsiveness to AVP, which is not related to vasopressin receptor overexpression, but may be explained by more efficient coupling pathways or by the indirect action of AVP through an autocrine/paracrine mechanism.


Assuntos
Adenoma/tratamento farmacológico , Neoplasias das Glândulas Suprarrenais/tratamento farmacológico , Síndrome de Cushing/tratamento farmacológico , Receptores de Vasopressinas/biossíntese , Vasoconstritores/farmacologia , Adenoma/fisiopatologia , Neoplasias das Glândulas Suprarrenais/fisiopatologia , Adulto , Estudos de Casos e Controles , Síndrome de Cushing/sangue , Feminino , Humanos , Hidrocortisona/sangue , Lipressina/análogos & derivados , Lipressina/farmacologia , Masculino , Pessoa de Meia-Idade , Receptores de Vasopressinas/efeitos dos fármacos , Índice de Gravidade de Doença , Terlipressina
7.
J Steroid Biochem Mol Biol ; 101(2-3): 127-35, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16901689

RESUMO

Aromatase protein is synthesized in response to gonadotropins that activate expression of their target genes via the cAMP second messenger system. The -882/+103 bp region of the rabbit ovarian promoter (PII) was ligated to a luciferase vector and transfected into granulosa cells to elucidated the mechanism by which cAMP stimulates transcription. Deletions and mutational experiments indicate that (i) a cAMP-response element-like sequence (CLS) present at -208 to -200 bp is the main element required for the activation of the rabbit PII by cAMP and that (ii) both nuclear receptor element sites; NREA (-133/-126 bp) and NREB (-188/-181 bp) do not participate to the cAMP-dependent activity of the PII. The replacement of the specific rabbit NREA site by the human NREA site increases two-fold the cAMP response and indicates that trans-activating factors are present in rabbit granulosa cells. This study shows for the first time an efficient aromatase transcription occurs in granulosa cells in absence of a consensus NREA site. In addition a comparative study has been performed on the sheep aromatase promoter where sites deviate from rabbit. Mutagenesis experiments suggest that some of them are involved in the cAMP-induced response of the rabbit PII.


Assuntos
Aromatase/genética , Células da Granulosa/enzimologia , Regiões Promotoras Genéticas , Ovinos/genética , Transcrição Gênica , Animais , Sequência de Bases , Células Cultivadas , AMP Cíclico/genética , Feminino , Proteínas de Homeodomínio/genética , Dados de Sequência Molecular , Coelhos , Receptores Citoplasmáticos e Nucleares/genética , Homologia de Sequência do Ácido Nucleico , Fator Esteroidogênico 1 , Fatores de Transcrição/genética , Ativação Transcricional , Transfecção
8.
Endocrinology ; 144(11): 4790-8, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12960046

RESUMO

In rabbit granulosa cells, two cytochrome P450 aromatase (P450 arom) mRNAs issued from promoter II were described: a full-length and a truncated transcript. Western blot analysis showed two P450 arom proteins with apparent molecular masses of 53 and 46 kDa, which are consistent with the predicted theoretical sizes of proteins encoded by these two transcripts. To examine the involvement of the truncated transcript in the regulation of P450 arom gene expression, the level of each transcript was specifically quantified in cultured granulosa cells by competitive quantitative RT-PCR. FSH induced a dose-dependent increase in both estradiol production and P450 arom mRNAs levels with a much more enhancement in the full-length mRNA. The half-life of the transcripts could not explain this differential regulation. Upon dibutyryl cAMP stimulation, the full-length mRNA was less abundant than the truncated one. In contrast, Western blot analysis revealed a stimulation of the 53-kDa protein content, whereas the 46-kDa protein amount was apparently unaffected. TGF beta in FSH-stimulated conditions decreased both estradiol production and P450 arom transcripts levels. TGF beta did not modify estradiol production and aromatase protein amounts induced by dibutyryl cAMP, whereas the two P450 arom mRNAs levels were increased. In conclusion, we report for the first time that a protein encoded by a truncated P450 arom mRNA could be involved in the regulation of estrogen production. Moreover, we show that the two P450 arom mRNAs are regulated in a differential manner, probably through hormonal control of the alternative splicing.


Assuntos
Aromatase/genética , Fase Folicular/metabolismo , Regulação da Expressão Gênica , Variação Genética , Células da Granulosa/enzimologia , RNA Mensageiro/metabolismo , Animais , Aromatase/metabolismo , Sequência de Bases/genética , Bucladesina/farmacologia , Células Cultivadas , Estradiol/biossíntese , Feminino , Hormônio Foliculoestimulante/farmacologia , Dados de Sequência Molecular , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Estabilidade de RNA , Coelhos , Fator de Crescimento Transformador beta/farmacologia
9.
Eur J Endocrinol ; 148(4): 457-61, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12656667

RESUMO

A 30-year-old male was referred for the rapid development of gynecomastia, and dramatic hyperestrogenemia was assessed: plasma estrone, estradiol but also cortisol were not suppressed by high-dose dexamethasone, while gonadotropin pulsatility was completely abolished. A 60-mm right adrenal tumor was evidenced on computed tomography-scan, and the patient underwent adrenalectomy. The tumor was found to express a moderate increase in aromatase activity compared with adjacent non-neoplastic adrenal tissue. Quantitative RT-PCR also showed a weak and non-significant increase in total aromatase mRNA in the tumor compared with normal adrenal tissue. Aromatase transcripts were mainly promoter PII-derived, but different patterns of aromatase minor transcripts were found: promoter I.3- and I.6-derived transcripts were identified in the tumor, while only promoter I.4-derived transcripts were found in normal adrenal. This case report demonstrates that a sharp aromatase overexpression is not a prerequisite for clinical and biochemical hyperestrogenism, and further characterizes the aromatase promoter utilization in this feminizing adrenocortical tumor and in the normal adrenal cortex.


Assuntos
Adenoma/complicações , Neoplasias do Córtex Suprarrenal/complicações , Aromatase/genética , Estrogênios/sangue , Feminização/etiologia , Expressão Gênica , 17-alfa-Hidroxiprogesterona/análise , Adenoma/enzimologia , Adenoma/cirurgia , Córtex Suprarrenal/química , Neoplasias do Córtex Suprarrenal/enzimologia , Neoplasias do Córtex Suprarrenal/cirurgia , Adrenalectomia , Adulto , Androstenodiona/análise , Aromatase/metabolismo , Estradiol/análise , Estrona/análise , Ginecomastia/etiologia , Humanos , Masculino , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testosterona/análise
10.
Eur J Endocrinol ; 168(3): 437-44, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23243014

RESUMO

BACKGROUND: The bone morphogenetic proteins (BMPs) are growth factors involved in the folliculogenesis. Alteration in their expression may compromise the reproductive process in disease such as the polycystic ovary syndrome (PCOS). This study investigated the expression and role of granulosa cell (GC) BMP from normal cycling and PCOS women. METHODS AND RESULTS: This prospective study was performed in GCs obtained from 14 patients undergoing IVF: i) six women with normal ovulatory cycles and tubal or male infertility and ii) eight women with PCOS. BMP2, BMP4, BMP5, BMP6, BMP7, and BMP8A and their receptors BMPR1A, BMPR1B, and BMPR2 were identified by RT-PCR in GCs from normally cycling and PCOS women. BMP4, BMP6, and BMP7 expressions were confirmed by immunohistochemistry. Quantitative transcript analysis showed the predominant expression of BMP6. In GCs from PCOS women, an overexpression of BMP6 (P<0.01) and BMPR1A mRNA (P<0.05) was observed. GC culture experiments demonstrated that basal estradiol (E2) production was threefold higher but FSH-induced E2 increment was twofold lower in PCOS compared with controls. In PCOS, BMP6 and BMP7 exerted a stimulatory effect on basal E2 production while BMP4 and BMP6 inhibited FSH-induced E2 production. FSH receptor and aromatase expression were not different between both groups. CONCLUSION: The BMP system is expressed in human GCs from normal cycling and PCOS women. The BMP may be involved in reproductive abnormalities found in PCOS.


Assuntos
Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Regulação da Expressão Gênica , Células da Granulosa/metabolismo , Síndrome do Ovário Policístico/metabolismo , Esteroides/metabolismo , Adulto , Proteína Morfogenética Óssea 4/genética , Proteína Morfogenética Óssea 4/metabolismo , Proteína Morfogenética Óssea 6/genética , Proteína Morfogenética Óssea 6/metabolismo , Proteína Morfogenética Óssea 7/genética , Proteína Morfogenética Óssea 7/metabolismo , Receptores de Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/genética , Células Cultivadas , Estradiol/metabolismo , Feminino , Hormônio Foliculoestimulante Humano/metabolismo , Células da Granulosa/patologia , Humanos , Imuno-Histoquímica , Síndrome do Ovário Policístico/patologia , Estudos Prospectivos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Mensageiro/metabolismo , Adulto Jovem
11.
Eur J Endocrinol ; 160(1): 93-9, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18974231

RESUMO

OBJECTIVE: The aromatase enzyme catalyzes the final stage of estrogen biosynthesis pathway from androgens. Its expression in the adrenal is poorly studied except for the rare estrogen-producing adrenocortical tumors. In order to further characterize aromatase expression in the adrenal, we evaluated the aromatase enzyme activity, Cyp19a1 gene expression level, and promoter utilization in normal adrenal tissues and in adrenocortical secreting tumors. DESIGN AND METHODS: Six normal adult adrenals (NA), 2 feminizing adrenal tumors (FT), 10 cortisol-producing adenomas with overt (CS, n=4) or sub-clinical Cushing syndrome (SCS, n=6) and 3 aldosterone-producing adenomas (APA) were studied. Tissue aromatase activity was determined by the tritiated ((3)H)-water method. Total aromatase mRNA were measured by a competitive RT-PCR. Promoter regions PII and PI.4-derived transcripts were also studied in NA, FT, and other steroid-producing tumors by a semi-quantitative comparative RT-PCR. Immunofluorescence analysis was performed in normal human adrenal tissues. RESULTS: Aromatase activity was detected in NA tissues and in all tumor subtypes, at high levels in both FT. In NA, aromatase immunofluorescence was detected in the cytoplasm of steroidogenic cells, mainly from zona reticularis. Compared with NA, aromatase transcript levels were similar in CS and APA, lower in SCS and similar or higher in FT. Promoter analysis suggested predominant PII utilization in NA, APA, and SCS, but similar PII and PI.4 utilization in CS tumors. CONCLUSION: Aromatase is expressed at similar levels in normal adrenal and in adrenocortical tumors, but at variably high levels in FT. Different promoter utilization patterns are found among tumor subtypes.


Assuntos
Neoplasias do Córtex Suprarrenal/enzimologia , Adenoma Adrenocortical/enzimologia , Aromatase/biossíntese , Neoplasias do Córtex Suprarrenal/genética , Adenoma Adrenocortical/genética , Adulto , Aromatase/genética , Síndrome de Cushing/enzimologia , Síndrome de Cushing/genética , Feminino , Humanos , Imuno-Histoquímica , Masculino , Microscopia de Fluorescência , Microscopia de Contraste de Fase , Regiões Promotoras Genéticas , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estatísticas não Paramétricas
12.
J Steroid Biochem Mol Biol ; 116(1-2): 110-7, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19460434

RESUMO

Transcription of the CYP19 gene encoding the aromatase P450 enzyme in ovarian cells is under the control of the two gonadotropins, follicle stimulating hormone (FSH) and luteinizing hormone (LH), via modulation of intracellular cyclic 3',5'-adenosine monophosphate (cAMP) levels. Primary cultures of rabbit ovarian cells were used to identify the functional regions of the ovarian promoter (PII) that are responsive to the gonadotropic secondary messenger and to estradiol. Transfection experiments in granulosa and luteal cells with deleted constructs of the PII promoter show that the region between -274 and -193bp is critical for cAMP-dependent transcriptional activity. A comparison of PII activities in granulosa and small luteal cells highlights a 50% decrease consecutive to the LH surge. Sequence analysis of the above mentioned region revealed the presence of a cAMP responsive element like sequence (CLS) and of a nuclear receptor element A (NREA). Binding of CREB to CLS has been shown using granulosa and luteal cells nuclear extracts. In addition, we identified the expression of NR5A1 (Steroidogenic Factor 1) and NR5A2 (Liver Receptor Homologue 1) in granulosa and luteal cells. However, the binding to NREA is observed only with granulosa cells nuclear extracts. Data suggest that the NR5A factors are not the main regulators of CYP19 gene, in contrast with the others genes of streroidogenesis enzymes, and additional sites may play an important role during the post-LH surge down-regulation of CYP19 transcription.


Assuntos
Aromatase/genética , Corpo Lúteo/metabolismo , AMP Cíclico/metabolismo , Fase Folicular/genética , Regulação da Expressão Gênica , Células da Granulosa/metabolismo , Animais , Células Cultivadas , Corpo Lúteo/citologia , Regulação para Baixo , Feminino , Células da Granulosa/citologia , Coelhos , Fator Esteroidogênico 1/genética , Fator Esteroidogênico 1/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção
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