RESUMO
The in vitro effect of progesterone in T. canis larvae on their enlargement and motility were evaluated, together to the possible presence of progesterone receptors (PRs). T. canis larvae were cultured in RPMI-1640 with different concentrations of progesterone (0, 20, 40, 80, 400 and 800 ng/mL). Enlargement and increases in motility were dependent on the concentration only from 0 to 80 ng/mL (p < 0.05). The mean percentage of PR + cells in newly obtained larvae as measured by flow cytometry was 8.16 ± 0.4. The number of PR + cells increased depending on concentration from 0 to 80 ng/mL (p < 0.001). Cells obtained from larvae stimulated at any of the studied hormone concentrations showed greater mean fluorescence intensity when compared to non-stimulated cells. Additionally, the expression and location of PR + cells were determined in the larvae. The sequence of an amplicon (420-bp) obtained by PCR from T. canis larvae showed 100% homology with a gene fragment that codes for the PR of the dog. PR + cells were immunolocated using confocal microscopy in the intestinal region of the larvae that had been recently obtained. The results of this study show that T. canis larvae can recognize and respond to the presence of progesterone through a molecule possibly able to bind it. Since we previously observed a similar response to prolactin, we suggest that both hormones could participate sequentially in the reactivation of T. canis larvae in pregnant bitches.
Assuntos
Progesterona/farmacologia , Progestinas/farmacologia , Receptores de Progesterona/efeitos dos fármacos , Toxocara canis/efeitos dos fármacos , Animais , Sequência de Bases , DNA de Helmintos/química , DNA de Helmintos/isolamento & purificação , Cães , Feminino , Citometria de Fluxo , Intestinos/parasitologia , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Camundongos , Microscopia Confocal , Movimento/efeitos dos fármacos , Reação em Cadeia da Polimerase , Receptores de Progesterona/análise , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Toxocara canis/crescimento & desenvolvimento , Toxocara canis/fisiologiaRESUMO
OBJECTIVE: Ulispristal acetate (UPA) is a selective progesterone receptor modulator widely used for emergency contraception (EC). The described main mechanism of action is by inhibiting or delaying ovulation; however, the postovulatory effects of the drug are still on debate. Therefore, the aim of this study was to determine whether UPA could interfere with human sperm fertilizing ability. STUDY DESIGN: Human motile spermatozoa were incubated under capacitating conditions with or without UPA, and then used to inseminate human tubal explants, mouse cumulus-oocyte complexes and zona-free hamster eggs. The ability of UPA to interact with human sperm progesterone (P)-binding sites was investigated by incubating the cells with fluorescent-labeled P and analyzing them by fluorescence microscopy. RESULTS: UPA did not affect the ability of human sperm to bind to human tubal tissue explants surface or to penetrate the mouse cumulus mass and the zona-free hamster eggs. In addition, concentrations of UPA much higher than those present in the plasma of EC pill users were required to bind to human sperm P-binding sites. CONCLUSIONS: Our study supports a lack of an agonist or antagonist action of UPA on different functional parameters associated with the fertilizing ability of human sperm. IMPLICATIONS: This study provides new functional evidence supporting that the contraceptive action of UPA is not related to effects on human sperm cells, contributing to a better understanding of the mechanism of action of UPA as EC.
Assuntos
Anticoncepcionais Femininos/farmacologia , Tubas Uterinas/metabolismo , Norpregnadienos/farmacologia , Interações Espermatozoide-Óvulo/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia , Animais , Sítios de Ligação/efeitos dos fármacos , Anticoncepção Pós-Coito , Cricetinae , Células do Cúmulo/fisiologia , Feminino , Humanos , Masculino , Camundongos , Norpregnadienos/metabolismo , Progesterona/metabolismo , Receptores de Progesterona/efeitos dos fármacosRESUMO
OBJECTIVE: A prospective randomized controlled trial was conducted to evaluate the effect of low dose of tibolone on the histology, expression of estrogen (ER) and progesterone receptors (PR) and Bcl-2 protein, in endometrium of postmenopausal women. METHOD: Forty postmenopausal women consented to treatment and were allocated into two groups of 20 women: Group 1 (Control) without hormone replacement therapy (HRT); Group 2 (Tibolone) treatment at the dose of 1.25 mg/day of oral tibolone administered for a 24-week period. The effect on the endometrium was assessed by histology and the apoptosis marker Bcl-2. The immunoexpression of ER and PR were also measured. RESULTS: Tibolone group showed higher expression of ER, PR and Bcl-2 protein in glandular epithelium and stroma compared to control group. CONCLUSION: Tibolone in a daily dose of 1.25 mg during 24 weeks demonstrated endometrial action that resulted in low proliferation and was shown to lead to atrophic endometrium. It had favorable effects on the postmenopausal endometrium due to its higher immunoexpression of PR and Bcl-2 protein in endometrial glandular epithelium, thereby creating a balance between pro-apoptotic and anti-apoptotic actions.
Assuntos
Endométrio/efeitos dos fármacos , Moduladores de Receptor Estrogênico/uso terapêutico , Terapia de Reposição de Estrogênios/métodos , Norpregnenos/uso terapêutico , Método Duplo-Cego , Endométrio/metabolismo , Moduladores de Receptor Estrogênico/administração & dosagem , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Norpregnenos/administração & dosagem , Pós-Menopausa , Estudos Prospectivos , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/efeitos dos fármacos , Receptores de Estrogênio/biossíntese , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Progesterona/biossíntese , Receptores de Progesterona/efeitos dos fármacosRESUMO
STUDY QUESTION: Does ulipristal acetate (UPA), a selective progesterone receptor modulator used for emergency contraception (EC), interfere with fertilization or early embryo development in vitro and in vivo? SUMMARY ANSWER: At doses similar to those used for EC, UPA does not affect mouse gamete transport, fertilization or embryo development. WHAT IS KNOWN ALREADY: UPA acts as an emergency contraceptive mainly by inhibiting or delaying ovulation. However, there is little information regarding its effects on post-ovulatory events preceding implantation. STUDY DESIGN, SIZE, DURATION: This was an in vitro and in vivo experimental study involving the use of mouse gametes and embryos from at least three animals in each set of experiments. PARTICIPANTS/MATERIALS, SETTING, METHODS: For in vitro fertilization experiments, mouse epididymal spermatozoa capacitated in the presence of different concentrations of UPA (0-1000 ng/ml) were used to inseminate cumulus-intact or cumulus-free eggs in the presence or absence of UPA during gamete co-incubation, and the percentage of fertilized eggs was determined. For in vivo fertilization experiments, superovulated females caged with proven fertile males were injected with UPA (40 mg/kg) or vehicle just before or just after mating and the percentage of fertilized eggs recovered from the ampulla was determined. To investigate the effect of UPA on embryo development, zygotes were recovered from mated females, cultured in the presence of UPA (1000 ng/ml) for 4 days and the progression of embryo development was monitored daily. MAIN RESULTS AND THE ROLE OF CHANCE: In vitro studies revealed that the presence of UPA during capacitation and/or gamete co-incubation does not affect fertilization. Whereas the in vivo administration of UPA at the same time as hCG injection produced a decrease in the number of eggs ovulated compared with controls (vehicle injected animals, P < 0.05), no effects on fertilization were observed when UPA was administered shortly before or after mating. No differences were observed in either the percentage of cleaved embryos or the cleavage speed when UPA was present during in vitro embryo culture. LIMITATIONS, REASONS FOR CAUTION: Considering the ethical and technical limitations inherent to the use of human gametes for fertilization studies, the mouse model was used as an approach for exploring the potential effects of UPA on in vivo sperm transport and fertilization. Nevertheless, the extrapolation of these results to humans requires further investigation. WIDER IMPLICATIONS OF THE FINDINGS: This study presents new evidence on the lack of effect of UPA on gamete interaction and embryo development, providing new insights into the mechanism of action of UPA as an emergency contraceptive method with potential clinical implications. These new findings could contribute to increase the acceptability and proper use of UPA as an emergency contraceptive method. STUDY FUNDING/COMPETING INTERESTS: This study was partially supported by a National Agency of Scientific and Technological Promotion (ANPCyT), Argentina grants PICT 2011-061 to D.J.C. and PICT 2011-2023 to P.S.C. None of the authors has any competing interests to declare.
Assuntos
Desenvolvimento Embrionário/efeitos dos fármacos , Fertilização in vitro/efeitos dos fármacos , Norpregnadienos/farmacologia , Receptores de Progesterona/efeitos dos fármacos , Interações Espermatozoide-Óvulo/efeitos dos fármacos , Animais , Anticoncepção Pós-Coito , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
The control of complement activation in the embryo-maternal environment has been demonstrated to be critical for embryo survival. Complement proteins are expressed in the human endometrium; however, the modulation of this expression by embryo signals has not been explored. To assess the expression of complement proteins in response to human chorionic gonadotropin (hCG), we designed an experimental study using in vivo and in vitro models. Twelve fertile women were treated with hCG or left untreated during the mid-luteal phase, and an endometrial biopsy was performed 24 hours later. The localizations of C3, membrane cofactor protein (MCP; CD46), decay-accelerating factor (DAF; CD55), and protectin (CD59) were assessed by immunohistochemistry, and the messenger RNA (mRNA) levels of these proteins were quantified by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) in cells harvested from endometrial compartments using laser capture microdissection. Endometrial explants were cultured with or without hCG for 24 hours, and the C3 and DAF protein levels were measured by Western blotting. Elevated C3 mRNA levels in stromal cells and elevated DAF levels in epithelial luminal cells were detected after hCG treatment. In the endometrial explant model, the progesterone receptor antagonist RU486 inhibited the increases in the levels of C3 and DAF in response to hCG. The findings of this study indicate that hCG plays a role in embryo-endometrium communication and affects the expression of complement proteins in endometrial compartments during the implantation window.
Assuntos
Antígenos CD55/metabolismo , Gonadotropina Coriônica/administração & dosagem , Complemento C3/metabolismo , Implantação do Embrião/efeitos dos fármacos , Endométrio/efeitos dos fármacos , Adulto , Antígenos CD55/genética , Antígenos CD59/genética , Antígenos CD59/metabolismo , Complemento C3/genética , Endométrio/imunologia , Endométrio/metabolismo , Feminino , Antagonistas de Hormônios/farmacologia , Humanos , Ciclo Menstrual/imunologia , Ciclo Menstrual/metabolismo , Mifepristona/farmacologia , RNA Mensageiro/metabolismo , Receptores de Progesterona/efeitos dos fármacos , Receptores de Progesterona/metabolismo , Fatores de Tempo , Técnicas de Cultura de TecidosRESUMO
In C4-HD murine mammary carcinomas and in human breast cancer T47D cells, we showed that medroxyprogesterone acetate (MPA) induces a nuclear physical association between estrogen receptor alpha (ERa) and progesterone receptors (PR). The blockade of ERa inhibits cell proliferation mediated by progestins. We hypothesized that this nuclear association between ERa/PR is necessary to trigger progestin-induced cell proliferation and tumor growth. We demonstrated that fulvestrant (FUL, ICI182.780) induced complete regression of C4-HD tumors growing with progestins. MPA treatment induced an early increase in both CCND1 and MYC expression in T47D cells. The blockade of ERa prevented the MPA-dependent transcription of both genes. Specific binding of PR/ERa was observed at the same MPA-sensitive regions at the CCND1 and MYC gene promoters after chromatin immunoprecipitation (ChIP) analysis. ICI inhibited binding of ERa to both gene regulatory sequences while PR binding was unaffected. The nuclear colocalization between both receptors in T47D cells was confirmed by: confocal microscopy, Duolink assays and co-immunoprecipitation assays. In breast cancer samples we also observed a nuclear interaction between both steroid receptors. Our results indicate that the presence of ERa interacting with activated PR at the CCND1 and MYC promoters is required to trigger progestin-induced gene transcription and cell proliferation in breast cancer cells.
Assuntos
Carcinoma/patologia , Estradiol/análogos & derivados , Receptor alfa de Estrogênio/fisiologia , Neoplasias Mamárias Experimentais/patologia , Receptores de Progesterona/fisiologia , Animais , Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/genética , Carcinoma/induzido quimicamente , Carcinoma/tratamento farmacológico , Proliferação de Células , Imunoprecipitação da Cromatina , Ciclina D1/metabolismo , Estradiol/administração & dosagem , Receptor alfa de Estrogênio/efeitos dos fármacos , Feminino , Fulvestranto , Genes myc , Humanos , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/tratamento farmacológico , Acetato de Medroxiprogesterona/farmacologia , Murinae , Progestinas/metabolismo , Receptores de Progesterona/efeitos dos fármacos , Transcrição GênicaRESUMO
OBJECTIVE: To study in vivo the progesterone receptor (PR) expression levels in human granulosa cells (GCs) during the periovulatory period and the affect of the protein kinase A (PKA) pathway on PR expression and cathepsin-L expression-activation. DESIGN: Experimental study. SETTING: University research unit. PATIENT(S): Twenty-five women of reproductive age. INTERVENTION(S): Follicular fluid and GCs obtained from spontaneous cycles before and during the normal luteinizing hormone surge, and samples obtained 36 hours after human chorionic gonadotropin (hCG) administration in patients undergoing in vitro fertilization. MAIN OUTCOME MEASURE(S): To determine PR, cathepsin-L messenger RNA (mRNA) analysis via real-time polymerase chain reaction, and protein of PR, cathepsin-L, and PKA in human GCs. RESULT(S): The Western blot analysis revealed that bands of PR (isoform A) were the most abundant and that mRNA (PR-A and PR-B) have a temporal pattern of expression throughout the periovulatory period. The protein levels of PR and cathepsin-L were up-regulated by hCG. The abundance of PR was diminished in the presence of PKA inhibitor, and cathepsin-L with PR receptor antagonist. CONCLUSION(S): The transient expression of PR in human GCs of the preovulatory follicle suggests that PR and its ligand play a role in the activation of cathepsin-L, which is presumably involved in the degradation of the follicular extracellular matrix during human ovulation.
Assuntos
Catepsina L/metabolismo , Células da Granulosa/enzimologia , Ovulação , Receptores de Progesterona/metabolismo , Adulto , Western Blotting , Catepsina L/genética , Células Cultivadas , Gonadotropina Coriônica/administração & dosagem , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ativação Enzimática , Feminino , Fármacos para a Fertilidade Feminina/administração & dosagem , Líquido Folicular/metabolismo , Células da Granulosa/efeitos dos fármacos , Antagonistas de Hormônios/farmacologia , Humanos , Ovulação/efeitos dos fármacos , Indução da Ovulação , Inibidores de Proteínas Quinases/farmacologia , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Progesterona/efeitos dos fármacos , Receptores de Progesterona/genética , Fatores de TempoRESUMO
This study investigates the effects of neonatal exposure to low doses of endosulfan on the expression of proteins regulating uterine development and differentiation. Female pups received vehicle, endosulfan (Endo6: 6 µg/kg, Endo600: 600 µg/kg) or diethylstilbestrol (DES: 0.2 µg/kg) from postnatal day 1 (PND1) to PND7. The uterine expression of estrogen receptor alpha (ERα), progesterone receptor (PR), Hoxa10 and alpha smooth muscle actin (α-SMA) was detected by immunohistochemistry on PND8 (neonatal period) and PND21 (prepubertal period), to evaluate acute and short-term responses. ERα, Hoxa10 and α-SMA were induced in the Endo600 group in both ages, while a striking decrease in PR expression was detected in the prepubertal rats following each dose of endosulfan. DES treatment deregulated ERα and Hoxa10 uterine expression at each age. Studies are currently underway to investigate whether the dysregulation of steroid receptors, Hoxa10 and α-SMA observed following neonatal exposure to endosulfan affect uterine functions in adulthood.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Endossulfano/toxicidade , Inseticidas/toxicidade , Útero/efeitos dos fármacos , Actinas/metabolismo , Animais , Animais Recém-Nascidos , Dietilestilbestrol/toxicidade , Relação Dose-Resposta a Droga , Disruptores Endócrinos/administração & dosagem , Endossulfano/administração & dosagem , Receptor alfa de Estrogênio/efeitos dos fármacos , Receptor alfa de Estrogênio/metabolismo , Feminino , Proteínas Homeobox A10 , Proteínas de Homeodomínio/metabolismo , Imuno-Histoquímica , Inseticidas/administração & dosagem , Gravidez , Ratos , Ratos Wistar , Receptores de Progesterona/efeitos dos fármacos , Receptores de Progesterona/metabolismo , Fatores de Tempo , Útero/crescimento & desenvolvimento , Útero/metabolismoRESUMO
We evaluated the in vitro effects of estradiol, progesterone, and testosterone on the molting process, which is the initial and crucial step in the development of the muscular larvae (ML or L1) to adult worm. Testosterone had no significative effect on the molting rate of the parasite, however, progesterone decreased the molting rate about a 50% in a concentration- and time-independent pattern, while estradiol had a slight effect (10%). The gene expression of caveolin-1, a specific gene used as a marker of parasite development, showed that progesterone and estradiol downregulated its expression, while protein expression was unaffected. By using flow citometry, a possible protein that is recognized by a commercial antiprogesterone receptor antibody was detected. These findings may have strong implications in the host-parasite coevolution, in the sex-associated susceptibility to this infection and could point out to possibilities to use antihormones to inhibit parasite development.
Assuntos
Expressão Gênica/fisiologia , Hormônios Esteroides Gonadais/metabolismo , Helmintíase/parasitologia , Interações Hospedeiro-Parasita/fisiologia , Muda/fisiologia , Receptores de Progesterona/metabolismo , Trichinella spiralis/crescimento & desenvolvimento , Animais , Caveolina 1/efeitos dos fármacos , Caveolina 1/metabolismo , Regulação para Baixo/efeitos dos fármacos , Estradiol/metabolismo , Estradiol/farmacologia , Feminino , Expressão Gênica/efeitos dos fármacos , Hormônios Esteroides Gonadais/farmacologia , Helmintíase/tratamento farmacológico , Humanos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Muda/efeitos dos fármacos , Progesterona/metabolismo , Progesterona/farmacologia , Receptores de Progesterona/efeitos dos fármacos , Testosterona/metabolismo , Testosterona/farmacologia , Trichinella spiralis/efeitos dos fármacosRESUMO
Progesterone exerts a variety of actions in the brain through the interaction with its receptors (PR) which have two isoforms with different function and regulation: PR-A and PR-B. Progesterone may modulate neurotransmission by regulating the expression of neurotransmitters synthesizing enzymes or their receptors in several brain regions. The role of PR isoforms in this modulation is unknown. We explored the role of PR isoforms in the regulation of tryptophan (TPH) and tyrosine (TH) hydroxylase, and glutamic acid decarboxylase (GAD) expression in the hypothalamus of ovariectomized rats. Two weeks after ovariectomy, animals were subcutaneously injected with 5 µg of estradiol benzoate (EB), and 40 h later, progesterone (P) was intracerebroventricularly (ICV) injected. Each animal received two ICV injections of 1 µg/µl (4 nmol) of PR-B and total PR (PR-A+PR-B) sense or antisense (As) oligonucleotides (ODNs). First injection was made immediately before sc EB injection, and 24h later animals received the second one. Twenty-four hours after P administration, rats were euthanized and brains removed to measure the expression of PR-A and PR-B, TPH, TH and GAD by Western blot. We observed that sense ODNs modified neither PR isoforms nor enzymes expression in the hypothalamus, whereas PR A+B antisense (PR A+B As) clearly decreased the expression of both PR isoforms in this region. ICV administration of PR-B As only decreased PR-B isoform expression with no significant effects on PR-A expression. A differential protein expression of TPH, TH and GAD was observed after PR isoforms antisense administration. PR-B As administration decreased the expression of TPH (65% with respect to control). In contrast, PR A+B As and PR-B As administration increased (51.6% and 34.4%, respectively) TH expression. The administration of PR A+B As and PR-B As diminished GAD expression (33.4% and 41.6%, respectively). Our findings indicate that PR isoforms play a differential role in the regulation of the content of TPH, TH and GAD in the rat hypothalamus.
Assuntos
Glutamato Descarboxilase/biossíntese , Hipotálamo/enzimologia , Receptores de Progesterona/metabolismo , Triptofano Hidroxilase/biossíntese , Tirosina 3-Mono-Oxigenase/biossíntese , Animais , Western Blotting , Estradiol/análogos & derivados , Estradiol/farmacologia , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/fisiologia , Hipotálamo/efeitos dos fármacos , Injeções Intraventriculares , Isomerismo , Oligonucleotídeos Antissenso , Ovariectomia , Ratos , Ratos Sprague-Dawley , Receptores de Progesterona/química , Receptores de Progesterona/efeitos dos fármacosRESUMO
AIMS AND BACKGROUND: Histological and immunohistochemical findings may vary in cases of breast cancer. Possible changes in tumor markers between biopsies performed before and after neoadjuvant chemotherapy are controversial and pose a challenge when a clinical decision is needed. The objectives of the present study were: (i) to compare the immunohistochemical expression of estrogen, progesterone and prolactin receptors and HER-2/neu in breast cancer before and after neoadjuvant chemotherapy; and (ii) to correlate the expression of these tumor markers with partial tumor response to neoadjuvant chemotherapy. METHODS AND STUDY DESIGN: Immunohistochemical staining for breast tumor markers was performed in 90 cases of breast cancer. Statistical analysis was carried out using Fisher's exact test, McNemar's test, Spearman's correlation and the Kappa index with linear weighting (k). RESULTS: Agreement between markers before and after neoadjuvant chemotherapy was fair to moderate (k = 0.37-0.51). The immunohistochemical expression of HER-2/neu and prolactin receptors showed a significant, albeit weak correlation before and after neoadjuvant chemotherapy (HER-2/neu, rho = 0.34; P = 0.0009; k = 0.35 [95% CI, 0.19-0.51]). Prolactin status changed in 28/90 cases (P = 0.001; McNemar's test), whereas no changes were found in estrogen or progesterone receptors. No association was found between tumor marker expression and tumor response. CONCLUSIONS: It seems prudent to reevaluate immunohistochemical markers such as HER-2/neu after neoadjuvant chemotherapy, since the findings will guide the strategy for implementation of adjuvant systemic treatment. No correlation was found between the tumor markers analyzed in the present study and partial tumor response to neoadjuvant chemotherapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/tratamento farmacológico , Terapia Neoadjuvante/métodos , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Receptores da Prolactina/metabolismo , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Ductal de Mama/tratamento farmacológico , Carcinoma Lobular/tratamento farmacológico , Quimioterapia Adjuvante , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Receptor ErbB-2/efeitos dos fármacos , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Progesterona/efeitos dos fármacos , Receptores da Prolactina/efeitos dos fármacosRESUMO
Steroid hormones play an important role in reproduction and the receptors through which they signal change in a developmental time, follicle stage, and cell-specific manner. Disruption in steroid receptor expression affects follicle formation and differentiation. In this study, using prenatal testosterone (T) and dihydrotestosterone (DHT)-treated female sheep as model systems, we tested the hypothesis that prenatal androgen excess disrupts the developmental ontogeny of ovarian steroid receptor protein expression. Pregnant Suffolk ewes were injected twice weekly with T propionate or DHT propionate (a non-aromatizable androgen) in cottonseed oil from days 30 to 90 of gestation. Changes in ovarian estrogen receptors (ER; ESR1, ESR2), androgen receptor (AR) and progesterone receptor (PGR) proteins were determined at fetal (days 90 and 140), postpubertal (10 months), and adult (21 months; only prenatal T-treated sheep studied) ages by immunohistochemistry. Prenatal T and DHT treatment induced selective increase in AR but not ER or PGR expression in the stroma and granulosa cells of fetal days 90 and 140 ovaries. An increase in ESR1 and decrease in ESR2 immunostaining coupled with increased AR expression were evident in granulosa cells of antral follicles of 10- and 21-month-old prenatal T but not DHT-treated females (analyzed only at 10 months). These findings provide evidence that an early increase in ovarian AR is the first step in the altered ovarian developmental trajectory of prenatal T-treated females, and manifestations of postnatal ovarian dysfunction are likely facilitated via altered equilibrium of antral follicular granulosa cell ER/AR protein expression.
Assuntos
Di-Hidrotestosterona/análogos & derivados , Ovário/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal , Receptores de Esteroides/efeitos dos fármacos , Propionato de Testosterona/administração & dosagem , Fatores Etários , Envelhecimento , Animais , Western Blotting , Di-Hidrotestosterona/administração & dosagem , Receptor alfa de Estrogênio/efeitos dos fármacos , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/efeitos dos fármacos , Receptor beta de Estrogênio/metabolismo , Feminino , Idade Gestacional , Imuno-Histoquímica , Ovário/citologia , Ovário/crescimento & desenvolvimento , Ovário/metabolismo , Gravidez , Receptores Androgênicos/efeitos dos fármacos , Receptores Androgênicos/metabolismo , Receptores de Progesterona/efeitos dos fármacos , Receptores de Progesterona/metabolismo , Receptores de Esteroides/metabolismo , OvinosRESUMO
A number of clinical studies have demonstrated that norethisterone (NET), a potent synthetic progestin, restores postmenopausal bone loss, although its mode of action on bone cells is not fully understood, while the effect of naturally occurring progesterone in bone has remained controversial. A recent report claims that the potent effects of NET on osteoblastic cell proliferation and differentiation, mimicking the action of estrogens, are mediated by non-phenolic NET derivatives. To determine whether osteoblasts possess the enzymes required to bioconvert a progesterone receptor (PR) agonist into A-ring reduced metabolites with affinity to bind estrogen receptor (ER), we studied the in vitro metabolism of [(3)H]-labeled NET in cultured neonatal rat osteoblasts and the interaction of its metabolic conversion products with cytosolic -osteoblast ER, employing a competition analysis. Results indicated that NET was extensively bioconverted (36.4%) to 5 alpha-reduced metabolites, including 5 alpha-dihydro NET, 3 alpha,5 alpha-tetrahydro NET (3 alpha,5 alpha-NET) and 3beta,5 alpha-tetrahydro NET (3beta,5 alpha-NET), demonstrating the activities of 5 alpha-steroid reductase and two enzymes of the aldo-keto reductases family. Expression of Srd5a1 in neonatal osteoblast was well demonstrated, whereas Srd5a2 expression was not detected. The most striking finding was that 3beta,5 alpha-NET and 3 alpha,5 alpha-NET were efficient competitors of [(3)H]-estradiol for osteoblast ER binding sites, exhibiting affinities similar to that of estradiol. The results support the concept that the interplay of 5 alpha-steroid reductase and aldo-keto reductases in osteoblastic cells, acting as an intracrine modulator system is capable to bioconvert a PR agonist into ER agonists, offering an explanation of the molecular mechanisms NET uses to enhance osteoblastic cell activities.
Assuntos
Noretindrona/farmacologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/enzimologia , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Progesterona/efeitos dos fármacos , Oxirredutases do Álcool , Aldeído Redutase , Aldo-Ceto Redutases , Animais , Células Cultivadas , Colestenona 5 alfa-Redutase , Feminino , Ratos , Ratos WistarRESUMO
BACKGROUND: The contraceptive effect of the progestogen norethisterone (NET) and its main metabolites 5alpha-NET and 3beta,5alpha-NET has been demonstrated in several species, and most studies have focused on the effects of these compounds in the uterus. We previously reported that 5alpha-NET inhibits the progesterone (P(4))-induced acrosome reaction in pig and mouse spermatozoa and induces severe morphological damage in two-cell fertilized mouse oocytes. STUDY DESIGN: The main goal of this study was to analyze the possible role of P(4) receptor (PR) in the effects of NET and 5alpha-NET on the oocyte fertilization process. Different steroid treatments were used with or without cumulus-enclosed oocytes. RESULTS: It was demonstrated that NET increases the percentage of fertilized oocytes in the same manner as P(4) does, while 5alpha-NET reduces the percentage of fertilized oocytes. This effect was not reversed by P(4) in the same concentrations. CONCLUSION: A possible molecular mechanism for the effects of 5alpha-NET may be through a PR localized in the oocyte plasma membrane.
Assuntos
Anticoncepcionais Orais Sintéticos/farmacologia , Fertilização/efeitos dos fármacos , Noretindrona/farmacologia , Oócitos/metabolismo , Receptores de Progesterona/efeitos dos fármacos , Reação Acrossômica , Animais , Feminino , Fertilização/fisiologia , Fertilização in vitro , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Noretindrona/análogos & derivados , Distribuição Aleatória , Receptores de Progesterona/metabolismoRESUMO
Progestin regulation of gene expression was assessed in the progestin-dependent murine tumor line C4HD which requires MPA, a synthetic progestin, for in vivo growth and expresses high levels of progesterone receptor (PR). By using suppressive subtractive hybridization, caveolin-1 was identified as a gene whose expression was increased with in vivo MPA treatment. By Northern and Western blot analysis, we further confirmed that caveolin-1 mRNA and protein expression increased in MPA-treated tumors as compared with untreated tumors. When primary cultures of C4HD cells were treated in vitro with MPA, caveolin-1 levels also increased, effect that was abolished by pre-treatment with progestin antagonist RU486. In addition, MPA promoted strong caveolin-1 promoter transcriptional activation both in mouse and human breast cancer cells. We also showed that MPA regulation of caveolin-1 expression involved in activation of two signaling pathways: MAPK and PI-3K. Short-term MPA treatment of C4HD cells led to tyrosine phosphorylation of caveolin-1 protein, where Src was the kinase involved. Additionally, we showed that MPA-induced association of caveolin-1 and PR, which was detected by coimmunoprecipitation and by confocal microscopy. Finally, we proved that MPA-induced proliferation of C4HD cells was inhibited by suppression of caveolin-1 expression with antisense oligodeoxynucleotides to caveolin-1 mRNA. Furthermore, we observed that inhibition of caveolin-1 expression abrogated PR capacity to induced luciferase activity from a progesterone response element-driven reporter plasmid. Comprehensively, our results demonstrated for the first time that caveolin-1 expression is upregulated by progestin in breast cancer. We also demonstrated that caveolin-1 is a downstream effector of MPA that is partially responsible for the stimulation of growth of breast cancer cells.
Assuntos
Caveolina 1/fisiologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Mamárias Experimentais/patologia , Acetato de Medroxiprogesterona/farmacologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Caveolina 1/genética , Feminino , Sistema de Sinalização das MAP Quinases , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Fosfatidilinositol 3-Quinases/fisiologia , Fosforilação , Regiões Promotoras Genéticas , Receptores de Progesterona/efeitos dos fármacos , Receptores de Progesterona/fisiologia , Quinases da Família src/fisiologiaRESUMO
We studied the effects of oestradiol and progesterone on progesterone receptor (PR) isoform content in the brain of ovariectomized rats and in intact rats during the oestrous cycle by Western blot analysis. In the hypothalamus and the preoptic area of ovariectomized rats, PR-A and PR-B content was increased by oestradiol, whereas progesterone significantly diminished the content of both PR isoforms after 3 h of treatment in the hypothalamus, but not in the preoptic area. In the hippocampus, only PR-A content was significantly increased by oestradiol while progesterone significantly diminished it after 12 h of treatment. In the frontal cortex, no treatment significantly modified PR isoform content. During the oestrous cycle, the lowest content of PR isoforms in the hypothalamus was observed on diestrus day and, by contrast, in the preoptic area, the highest content of both PR isoforms was observed on diestrus day. We observed no changes in PR isoform content in the hippocampus during the oestrous cycle. These results indicate that the expression of PR isoforms is differentially regulated by sex steroid hormones in a regionally specific manner.
Assuntos
Química Encefálica/fisiologia , Estradiol/farmacologia , Ciclo Estral/fisiologia , Progesterona/farmacologia , Receptores de Progesterona/metabolismo , Animais , Western Blotting , Química Encefálica/efeitos dos fármacos , Estradiol/metabolismo , Estrogênios/metabolismo , Feminino , Isomerismo , Proteínas do Tecido Nervoso/metabolismo , Ovariectomia , Progesterona/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Progesterona/efeitos dos fármacosRESUMO
The purpose of this study was to evaluate the effect of the selective estrogen receptor modulators raloxifene and tamoxifen and of the pure antiestrogen fulvestrant on tumor growth and progesterone receptor (PR) expression in an experimental model of breast cancer. The effects of these compounds on cell proliferation were studied in primary cultures of a progestin-dependent mammary carcinoma tumor line, in the presence of medroxyprogesterone acetate (MPA) or 17-beta-estradiol (E2). In in vivo studies the tumor was inoculated subcutaneously in BALB/c female mice treated with 20 mg MPA depot. Raloxifene (12.5 mg/kg) or tamoxifen (5 mg/kg) were administered in daily doses or E2 silastic pellets (5 mg) were implanted. When the tumors reached about 25-50 mm2 MPA was removed in half of the animals. E2 induced complete tumor regressions, tamoxifen inhibited tumor growth in vivo while raloxifene disclosed proliferative effects in animals in which MPA had been removed. In vitro, E2 inhibited cell proliferation at concentrations higher than 10(-14)M. Raloxifene and fulvestrant, but not tamoxifen, partially reverted E2-induced inhibition. Fulvestrant and tamoxifen inhibited MPA-induced cell proliferation while raloxifene had a stimulatory effect. Tamoxifen and E2 increased, raloxifene induced no effect, and fulvestrant significantly decreased PR expression. In this study we provide evidence for differential effects of tamoxifen and raloxifene on experimental mammary tumors. Since raloxifene is under evaluation for use in breast cancer prevention, these results may have important clinical implications.
Assuntos
Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/tratamento farmacológico , Carcinoma Ductal de Mama/tratamento farmacológico , Gonadotropina Coriônica Humana Subunidade beta/farmacologia , Estradiol/farmacologia , Moduladores de Receptor Estrogênico/farmacologia , Meliteno/farmacologia , Cloridrato de Raloxifeno/farmacologia , Tamoxifeno/farmacologia , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Divisão Celular/efeitos dos fármacos , Estradiol/análogos & derivados , Feminino , Acetato de Medroxiprogesterona/farmacologia , Meliteno/análogos & derivados , Camundongos , Camundongos Endogâmicos BALB C , Receptores de Progesterona/efeitos dos fármacos , Células Tumorais CultivadasRESUMO
OBJECTIVE: Our aim was to study the effects of the gonadotropin releasing hormone agonist on the uterine leiomyoma of infertile women. MATERIAL AND METHODS: Sixty-seven nulliparous women (aged 24-39 years) with uterine leiomyomas, underwent ultrasonographic study of leiomyoma volume, and were divided in two groups. Thirty-one had nodes greater than 300 cm3 and were treated with goserelin 3.6 mg every 28 days for 6 months (group I); the other 36 patients did not receive medication (group II or control group). Sixteen patients from group I had < or = 36% (median) reduction of the leiomyoma volume (subgroup Ia) and the other 15 women had reduction > 36% (subgroup Ib). All women underwent myomectomy. RESULTS: The group with the greater leiomyoma reduction after treatment with goserelin (group Ib) showed a significantly lower percentage of ER+ when compared with group Ia and the control group. Group Ib had a significantly higher percentage of PR+ in relation to the control group, but not to group Ia. The number of blood vessels, AgNOR dots, and cells, and the amount of collagen were not different between the three groups studied. Leiomyomata reduction correlated negatively with the percentage ER+ cells, but positively with the PR+ cells, amount of collagen and number of blood vessels. No correlation was found between the number of AgNOR dots and cellularity. CONCLUSION: Our data strengthen the hypothesis that the uterine leiomyoma response to steroid hormones results from the presence of specific hormone receptors, and progesterone receptors may also play a role in the development of leiomyoma.
Assuntos
Antineoplásicos Hormonais/uso terapêutico , Gosserrelina/uso terapêutico , Leiomioma/tratamento farmacológico , Neoplasias Uterinas/tratamento farmacológico , Adulto , Feminino , Humanos , Leiomioma/patologia , Leiomioma/cirurgia , Miométrio/cirurgia , Paridade , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Progesterona/efeitos dos fármacos , Neoplasias Uterinas/patologia , Neoplasias Uterinas/cirurgia , Útero/patologiaRESUMO
In this document, we review the relevant aspects of the different medical methods of abortion. We describe the principal medical regimens currently used in North America, Europe, and a growing number of developing countries. We also describe specific treatment regimens (which usually involve a combination of two drugs), physiological methods of action, potential side effects and complications, method requirements, including follow-up visits, any existing contraindication, and acceptability of these methods among patients. Finally, we comment on the potential role of medical abortion in Mexico and throughout Latin America.
Assuntos
Aborto Induzido/métodos , Abortivos não Esteroides/farmacologia , Abortivos Esteroides/efeitos adversos , Abortivos Esteroides/farmacologia , Aborto Induzido/tendências , Neoplasias da Mama/tratamento farmacológico , Ensaios Clínicos como Assunto , Contraindicações , Interações Medicamentosas , Feminino , Seguimentos , Humanos , América Latina , Metotrexato/farmacologia , México , Mifepristona/efeitos adversos , Mifepristona/farmacologia , Misoprostol/farmacologia , Músculo Liso/efeitos dos fármacos , Aceitação pelo Paciente de Cuidados de Saúde , Educação de Pacientes como Assunto/métodos , Gravidez , Complicações na Gravidez/etiologia , Progestinas/antagonistas & inibidores , Progestinas/fisiologia , Prostaglandinas/química , Prostaglandinas/farmacologia , Receptores de Progesterona/efeitos dos fármacos , Tetra-Hidrofolato Desidrogenase/efeitos dos fármacos , Útero/efeitos dos fármacosRESUMO
Levonorgestrel (13beta-ethyl-17alpha-ethynyl-17beta-hydroxy-4-gonen-3-one), a potent contraceptive progestin stimulates growth and proliferation of cultured breast cancer cells through a receptor-mediated mechanism, even though levonorgestrel does not bind to the oestrogen receptor (ER). To assess whether the oestrogen-like effects induced by this synthetic progestin are exerted via its metabolic conversion products, we studied the binding affinity of three A-ring levonorgestrel derivatives to the ER and their capability to transactivate an oestrogen-dependent yeast system co-transfected with the human ER gene and oestrogen responsive elements fused to a beta-galactosidase reporter vector. The results demonstrated that the 3beta,5alpha reduced levonorgestrel derivative and to a lesser extent its 3alpha isomer interact with the oestrogen receptor, with a significantly lower relative binding affinity (2.4% and 0.4%, respectively) than that of oestradiol (100%), while levonorgestrel does not. Both levonorgestrel metabolites were able to activate, in a dose-dependent manner, the beta-galactosidase reporter gene in the yeast expression system, an effect that was precluded by a steroidal antioestrogen. The oestrogenic potency of levonorgestrel metabolites was significantly lower (750-fold) than that of oestradiol. Furthermore, high doses of 3beta,5alpha levonorgestrel (2.5 mg/day/6 days) induced an increase of oestrogen-dependent progestin receptor in the anterior pituitary of castrated rats. The overall data offer a plausible explanation for the weak oestrogenic effects induced by high, non-pharmacological doses of levonorgestrel.