RESUMEN
In vertebrates, gonadotropin-releasing hormone (GnRH) and gonadotropin-inhibitory hormone (GnIH), respectively, regulate reproduction in positive and negative manners. GnIH belongs to the LPXRFa family of peptides previously identified in mammalian and nonmammalian vertebrates. Studying the detailed distribution of LPXRFa as well as its receptor (LPXRFa-R) in the brain and pituitary is important for understanding their multiple action sites and potential functions. However, the distribution of LPXRFa and LPXRFa-R has not been studied in teleost species, partially because of the lack of fish-specific antibodies. Therefore, in the present study, we generated specific antibodies against LPXRFa and its receptor from Nile tilapia (Oreochromis niloticus), and examined their distributions in the brain and pituitary by immunohistochemistry. Tilapia LPXRFa-immunoreactive neurons lie in the posterior ventricular nucleus of the caudal preoptic area, whereas LPXRFa-R-immunoreactive cells are distributed widely. Double immunofluorescence showed that neither LPXRFa-immunoreactive fibers nor LPXRFa-R is closely associated or coexpressed with GnRH1, GnRH3, or kisspeptin (Kiss2) neurons. In the pituitary, LPXRFa fibers are closely associated with gonadotropic endocrine cells [expressing luteinizing hormone (LH) and follicle-stimulating hormone (FSH)], with adrenocorticomelanotropic cells [corticotropin (ACTH) and α-melanotropin (α-MSH)], and with somatolactin endocrine cells. In contrast, LPXRFa-R are expressed only in LH, ACTH, and α-MSH cells. These results suggest that LPXRFa and LPXRFa-R signaling acts directly on the pituitary cells independent from GnRH or kisspeptin and could play multiple roles in reproductive and nonreproductive functions in teleosts. J. Comp. Neurol. 524:2753-2775, 2016. © 2016 Wiley Periodicals, Inc.
Asunto(s)
Química Encefálica , Hormona Liberadora de Gonadotropina/análisis , Hormonas Hipotalámicas/análisis , Hipófisis/química , Receptores de Gonadotropina/análisis , Receptores LHRH/análisis , Animales , Encéfalo/metabolismo , Química Encefálica/fisiología , Hormona Liberadora de Gonadotropina/biosíntesis , Hormonas Hipotalámicas/biosíntesis , Masculino , Hipófisis/metabolismo , Receptores de Gonadotropina/biosíntesis , Receptores LHRH/biosíntesis , TilapiaRESUMEN
Ovarian follicles lacking FSH or FSH receptors fail to progress to a preovulatory stage, resulting in infertility. One hallmark of the preovulatory follicle is the presence of luteinizing hormone/choriogonadotropin receptors (LHCGR) on granulosa cells (GCs). However, the mechanisms by which FSH induces Lhcgr gene expression are poorly understood. Our results show that protein kinase A (PKA) and phosphoinositide 3-kinase (PI3K)/AKT pathways are required for FSH to activate both the murine Lhcgr-luciferase reporter and expression of Lhcgr mRNA in rat GCs. Based on results showing that an adenovirus (Ad) expressing a steroidogenic factor 1 (SF1) mutant that cannot bind ß-catenin abolished FSH-induced Lhcgr mRNA, we evaluated the role of ß-catenin in the regulation of Lhcgr gene expression. FSH promoted the PKA-dependent, PI3K-independent phosphorylation of ß-catenin on Ser552 and Ser665. FSH activated the ß-catenin/T-cell factor (TCF) artificial promoter-reporter TOPFlash via a PKA-dependent, PI3K-independent pathway, and dominant-negative (DN) TCF abolished FSH-activated Lhcgr-luciferase reporter and induction of Lhcgr mRNA. Microarray analysis of GCs treated with Ad-DN-TCF and FSH identified the Lhcgr as the most down-regulated gene. Chromatin immunoprecipitation results placed ß-catenin phosphorylated on Ser552 and Ser675 and SF1 on the Lhcgr promoter in FSH-treated GCs; TCF3 was constitutively associated with the Lhcgr promoter. Transduction with an Ad-phospho-ß-catenin mutant (Ser552/665/Asp) enhanced Lhcgr mRNA expression in FSH-treated cells greater than 3-fold. Finally, we identified a recognized PI3K/AKT target, forkhead box O1, as a negative regulator of Lhcgr mRNA expression. These results provide new understanding of the complex regulation of Lhcgr gene expression in GCs.
Asunto(s)
Células de la Granulosa/metabolismo , Folículo Ovárico/metabolismo , Receptores de Gonadotropina/metabolismo , Receptores de HL/metabolismo , Animales , Células Cultivadas , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Regulación hacia Abajo , Femenino , Hormona Folículo Estimulante/metabolismo , Factores de Transcripción Forkhead/metabolismo , Regulación de la Expresión Génica , Proteínas del Tejido Nervioso/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Mensajero/biosíntesis , Ratas , Ratas Sprague-Dawley , Receptores de Gonadotropina/biosíntesis , Receptores de Gonadotropina/genética , Receptores de HL/biosíntesis , Receptores de HL/genética , Transducción de Señal , Factor Esteroidogénico 1/genética , Factor Esteroidogénico 1/metabolismo , Proteína 1 Similar al Factor de Transcripción 7/metabolismo , Transfección , beta Catenina/metabolismoRESUMEN
Major depression is one of the most prevalent stress-related psychiatric diseases. Next to environmental influences such as chronic social stress, gender is among the strongest risk factors for major depression, with women having a twice as high risk to develop the disease compared to men. While there is abundant literature on the effects of chronic social stress in male rodents, there is a serious lack of information on gender-specific effects. Especially in mice, which due to the wide availability of transgenic lines offer a unique opportunity to study gene x environment interactions, there is no existing model of chronic social stress that is applicable to both sexes. We here describe the effects of chronic social stress based on the disruption of the social network in a group-housed situation in female mice, a model that was recently described and validated for male mice. In this model, the group composition of the mice is changed twice per week for a period of 7 weeks, covering the adolescent and early adulthood period. We observed that housing in an unpredictable social environment resulted in chronic stress in female mice. The observed effects, which included increased adrenal weight, decreased thymus weight, increased corticosterone levels, and increased anxiety-like behavior, were very similar to the described effects of this paradigm in male mice. In addition, we observed a distinct expression of stress system-related genes in female mice following chronic stress exposure. Our results validate this model as a suitable approach to study chronic social stress in female mice and open up the opportunity to use this model with transgenic or knockout mouse lines.
Asunto(s)
Medio Social , Estrés Psicológico/psicología , Hormona Adrenocorticotrópica/sangre , Animales , Ansiedad/psicología , Arginina Vasopresina/biosíntesis , Arginina Vasopresina/genética , Peso Corporal/fisiología , Corticosterona/sangre , Hormona Liberadora de Corticotropina/biosíntesis , Hormona Liberadora de Corticotropina/genética , Modelos Animales de Enfermedad , Conducta Alimentaria/fisiología , Femenino , Expresión Génica , Jerarquia Social , Hibridación in Situ , Masculino , Ratones , Actividad Motora/fisiología , Tamaño de los Órganos/fisiología , Receptores de Gonadotropina/biosíntesis , Receptores de Gonadotropina/genética , Caracteres SexualesRESUMEN
Exercise showed the beneficial effects on mental health in depressed sufferers, whereas, its underlying mechanisms remained unresolved. This study utilized the chronic unpredictable stress (CNS) animal model of depression to evaluate the effects of exercise on depressive behaviors and spatial performance in rats. Furthermore, we tested the hypothesis that the capacity of exercise to reverse the harmful effects of CNS was relative to the hypothalamo-pituitary-adrenal (HPA) system and brain-derived neurotrophic factor (BDNF) in the hippocampus. Animal groups were exposed to CNS for 4 weeks with and without access to voluntary wheel running. Stressed rats consumed significantly less of a 1% sucrose solution during CNS and exhibited a significant decrease in open field behavior. On the other hand, they showed impaired spatial performance in Morris water maze test 2 weeks after the end of CNS. Further, CNS significantly decreased hippocampal BDNF mRNA levels. However, voluntary exercise improved or even reversed these harmful behavioral effects in stressed rats. Furthermore, exercise counteracted a decrease in hippocampal BDNF mRNA caused by CNS. In addition, we also found that CMS alone increased circulating corticosterone (CORT) significantly and decreased hippocampal glucocorticoid receptor (GR) mRNA. At the same time, exercise alone increased CORT moderately and did not affect hippocampal GR mRNA levels. While, when both CNS and exercise were combined, exercise reduced the increase of CORT and the decrease of GR caused by CMS. The results demonstrated that: (1) exercise reversed the harmful effects of CNS on mood and spatial performance in rats and (2) the behavioral changes induced by exercise and/or CNS might be associated with hippocampal BDNF levels, and in addition, the HPA system might play different roles in the two different processes.
Asunto(s)
Depresión/metabolismo , Depresión/psicología , Condicionamiento Físico Animal/fisiología , Condicionamiento Físico Animal/psicología , Animales , Peso Corporal/fisiología , Factor Neurotrófico Derivado del Encéfalo/biosíntesis , Corticosterona/sangre , Conducta Exploratoria/fisiología , Hipocampo/metabolismo , Sistema Hipotálamo-Hipofisario/fisiopatología , Masculino , Actividad Motora/fisiología , Ratas , Ratas Sprague-Dawley , Receptores de Gonadotropina/biosíntesis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estrés Psicológico/psicología , Sacarosa/farmacologíaRESUMEN
Post-vitellogenic female rainbow trout (Oncorhynchus mykiss) were assayed in vitro for follicular maturational competence (FMC). Ovarian follicles were stimulated with a range of concentrations of partially purified gonadotropin. The efficient concentration for 50% germinal vesicle breakdown (GVBD) was calculated and used as an indicator of FMC. Before in vitro assay, ovarian tissue was sampled in order to quantify mRNA abundance of specific genes in the ovarian follicle by real-time PCR. In addition, maturation-inducing steroid (MIS, 17, 20 beta-dihydroxy-4-pregnen-3-one) and estradiol (E2) plasma levels were measured by radioimmunoassay. The mRNA expression of several genes such as luteinizing hormone receptor (LH-r), follicular stimulating hormone receptor (FSH-r), insulin-like growth factor 1 (IGF1), insulin-like growth factor 2 (IGF2), insulin-like growth factor receptor 1a (IGF-r1a), and 20 beta-hydroxysteroid dehydrogenase (20 beta-HSD) that are putatively expressed in the preovulatory ovary, was studied in females of varying FMC using real-time PCR. FMC acquisition is characterized by an increase of MIS circulating levels and a concomitant drop of E2 levels. At the ovarian level, no significant variation of LH-r, 20 beta-HSD, IGF1, and IGF-r1a mRNA abundance was observed among females of varying FMC. In contrast, FSH-r and IGF2 mRNA levels were significantly higher in females exhibiting high FMC. In addition, correlation analyses showed that IGF2 and FSH-r, mRNA levels were positively correlated with FMC. These results indicate that FMC acquisition is associated with an increased expression of these gene products that may be useful markers of FMC.
Asunto(s)
Factor II del Crecimiento Similar a la Insulina/genética , Folículo Ovárico/metabolismo , ARN Mensajero/metabolismo , Receptores de HFE/genética , Animales , Biomarcadores , Cortisona Reductasa/biosíntesis , Cortisona Reductasa/genética , Estradiol/sangre , Femenino , Factor II del Crecimiento Similar a la Insulina/biosíntesis , Oncorhynchus mykiss/metabolismo , Oocitos/metabolismo , Receptor IGF Tipo 1/biosíntesis , Receptor IGF Tipo 1/genética , Receptores de HFE/biosíntesis , Receptores de Gonadotropina/biosíntesis , Receptores de Gonadotropina/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Vertebrate reproduction is tightly regulated by conserved glycoprotein hormones produced by the pituitary gland. Follicle-stimulating hormone (FSH) in tetrapods and gonadotropic hormone I (GTH-I) in fishes are orthologous glycoprotein hormones that control the timing of egg production and the number of eggs produced. Zebrafish, a well-established genetic model for developmental biology, also offers potential advantages for studies of reproductive toxicology, especially for modeling the impact of pollutants on fish reproductive processes. To facilitate these studies we have identified, expressed, and characterized the zebrafish GTH-I receptor. This receptor (zfGTHR-I)exhibits strong sequence similarity to the tetrapod FSH receptors and to GTHR-I from salmon and catfish. Human 293 cells transfected with zfGTHR-I exhibit increased cAMP levels after treatment with carp pituitary extracts or human FSH, but not when treated with a ligand to a related receptor (human chorionic gonadotropin). Northern blotting and RT-PCR analyses indicate that zfGTHR is expressed in ovaries from sexually mature fish, but not in immature fish. Several alternative splice variants of the receptor affecting putative exons 2-4 that encode dramatically shortened receptor fragments lacking the transmembrane domain as well as regions previously implicated in ligand binding were identified by RT-PCR. The zfGTHR-I sequence opens the way to study effects of genetic mutations or chemicals on ovarian zfGTHR-I expression and function in zebrafish.
Asunto(s)
Receptores de Gonadotropina/fisiología , Reproducción/fisiología , Pez Cebra/fisiología , Empalme Alternativo/genética , Secuencia de Aminoácidos , Animales , Células COS , Clonación Molecular , Biología Computacional , AMP Cíclico/metabolismo , ADN Complementario/biosíntesis , ADN Complementario/genética , Mamíferos , Modelos Biológicos , Datos de Secuencia Molecular , Filogenia , Receptores de Gonadotropina/biosíntesis , Receptores de Gonadotropina/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Maduración Sexual/fisiología , Distribución TisularRESUMEN
The aim of this study was to determine if follicle stimulating hormone receptor and luteinizing hormone receptor (FSH-R and LH-R) expression is altered on granulosa cells (GC) of women with low oestradiol responses to FSH. Cells were obtained from mature follicles (>17 mm) following controlled ovarian stimulation. For comparison, chinese hamster ovary (CHO) cells transfected with FSH-R or LH-R were also assessed. FSH-R and LH-R expression were detected by flow cytometry. Receptors were labelled with FSH-R antibodies, or with excess FSH or human chorionic gonadotrophin (HCG) and anti-FSH or HCG antibodies, and compared to multiple controls. Receptor expression on GCs was more heterogeneous than on CHO cells. Gonadotrophin receptor levels on GCs were not correlated with the number of FSH ampoules administered or peak oestradiol response. Low and normal response groups were defined using a ratio of peak oestradiol/number of FSH ampoules. FSH receptor expression was not different on GCs from low and normal responders. However, LH-R expression was higher on GCs of low responders compared to those of normal responders (P = 0.04 ) suggesting a trend to more advanced luteinization. Access of hormone to follicles was not reduced in low responders. Thus, differences in gonadotrophin receptor expression, hormone binding, and access of hormones to follicles do not appear to account for low oestradiol responses to FSH.
Asunto(s)
Hormona Folículo Estimulante/fisiología , Células de la Granulosa/metabolismo , Receptores de Gonadotropina/biosíntesis , Adulto , Animales , Células CHO , Cricetinae , Femenino , Citometría de Flujo , Líquido Folicular/metabolismo , Humanos , Receptores de HL/metabolismoRESUMEN
Although serotonin (5-HT) has been shown to stimulate progesterone production by human granulosa-lutein cells (hGLC), the receptor type and associated signaling pathway remain uncharacterized. We report here that 5-HT receptors in these cells are positively coupled to adenylate cyclase activity. Formation of cAMP was stimulated by 5-HT and its agonists in a dose- and time-dependent manner. Mianserin, amoxapine, and loxapine were equipotent in antagonizing 5-HT-induced cAMP formation. For both cAMP formation in cells and adenylate cyclase assay using membrane fractions, the rank order of potency for agonists of 5-HT were: 5-carboxy-aminotryptamine >5-HT> or =5-methoxytryptamine, consistent with a typical pharmacological profile of human 5-ht7 (h5-ht7) receptor. Sequence data of amplified complementary DNA fragments reverse transcribed from hGLC RNA revealed complete identity with published sequence of h5-ht7 receptor complementary DNA. Northern analysis showed the presence of 2.8-kb h5-ht7 transcripts in hGLC. The three variants h5-ht7A, h5-ht7B, and h5-ht7D were also detected in hGLC. Preincubation of hGLC with 5-HT (10(-8)-10(-6) M) resulted in a marked reduction in the cAMP response when the cells were subsequently stimulated with gonadotropin, and this heterologous desensitization could be reversed by 5-ht7 receptor antagonist clozapine. These data demonstrate that h5-ht7 receptor is present and stimulate cAMP formation in hGLC. In addition, the h5-ht7 receptor seems to be implicated in the heterologous down-regulation hCG-stimulated cAMP response in hGLC, with a possible ramification for luteal insufficiency.
Asunto(s)
Adenilil Ciclasas/metabolismo , Células de la Granulosa/enzimología , Luteína/metabolismo , Receptores de Serotonina/metabolismo , Adenilil Ciclasas/genética , Adulto , Northern Blotting , Southern Blotting , Células Cultivadas , AMP Cíclico/fisiología , Regulación hacia Abajo/genética , Activación Enzimática/fisiología , Femenino , Fertilización In Vitro , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Humanos , Luteína/genética , Oocitos/citología , Progesterona/metabolismo , Receptores de Gonadotropina/biosíntesis , Receptores de Serotonina/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/genética , Transducción de Señal/fisiología , Esteroides/biosíntesisRESUMEN
A case of peritoneal papillary serous carcinoma arising in an infertile patient during ovulation-induction therapy is presented. A 34-year-old woman with past history of ovulation-induction therapy for infertility again received fertility drugs. During the use of gonadotropic hormones, massive ascites developed and an exploratory laparotomy revealed serous papillary carcinoma on the surface of bilateral ovaries, pelvic peritoneum, and omentum. Immunohistochemical analysis showed the tumor cells to be positive for luteinizing hormone/human chorionic gonadotropin receptors and negative for sex steroid receptors. A possible relationship between the use of gonadotropic hormones and cancer development is discussed.
Asunto(s)
Cistadenocarcinoma Papilar/metabolismo , Inducción de la Ovulación/efectos adversos , Neoplasias Peritoneales/metabolismo , Receptores de Estrógenos/biosíntesis , Receptores de Gonadotropina/biosíntesis , Receptores de Progesterona/biosíntesis , Adulto , Cistadenocarcinoma Papilar/etiología , Cistadenocarcinoma Papilar/patología , Femenino , Humanos , Infertilidad Femenina/terapia , Neoplasias Peritoneales/etiología , Neoplasias Peritoneales/patologíaRESUMEN
BACKGROUND: Gonadotropin-releasing hormone (Gn-RH) analogs have been used in the therapy of the endocrine-dependent cancers. The authors attempted to determine the frequency with which Gn-RH receptor (Gn-RHR) is present in gynecological cancers. METHODS: Experiments were performed on gynecologic tumors that had been surgically removed and their cloned cell lines. Gn-RHR was characterized by [3H]Gn-RH binding to plasma membrane preparations. Gn-RHR messenger ribonucleic acid was determined by reverse transcription-polymerase chain reaction using oligonucleotide primers synthesized according to the published human Gn-RHR sequence. RESULTS: High affinity binding sites with nanomolar range of Kd and Gn-RHR mRNA were detected in a high proportion (over 90%) of the specimens from endometrium (6 of 6) and endometrial carcinomas (16 of 17), myometrium (6 of 6) and myomas (4 of 5), epithelial carcinoma (21 of 23), and stromal tumors (3 of 3) of the ovary. There was no substantial Gn-RHR in cervical carcinomas or germ cell-derived tumors of the ovary. Cloned cell lines gave identical results to those obtained in their respective mother tumors. CONCLUSIONS: We detected Gn-RHR in a wide range of the carcinomas and tissues originating from the endometrium and ovary, but not in the uterine cervix or germ cell-derived tumors. The expression of Gn-RH receptor raises the possibility that Gn-RH may play a direct regulatory role in the growth of these carcinomas, and provides a possible point of attack for therapeutic approaches using Gn-RH analogs in these malignancies.
Asunto(s)
Neoplasias de los Genitales Femeninos/metabolismo , Receptores de Gonadotropina/biosíntesis , Adenocarcinoma/metabolismo , Secuencia de Bases , Femenino , Expresión Génica , Humanos , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , ARN Mensajero/análisis , ADN Polimerasa Dirigida por ARN , Ensayo de Unión Radioligante , Receptores de Gonadotropina/análisis , Células Tumorales CultivadasRESUMEN
The receptors for the gonadotropins differ from the other G protein-coupled receptors by having a large extracellular hormone-binding domain, encoded by nine or ten exons. Alternative splicing of the large pre-mRNA of approximately 100 kb can result in mRNA species that encode truncated receptor proteins. In this review we discuss the regulation of gonadotropin receptor mRNA expression and the possible roles of alternative splicing in gonadotropin receptor function.
Asunto(s)
Regulación de la Expresión Génica , Receptores de Gonadotropina/genética , Animales , Clonación Molecular , AMP Cíclico/fisiología , Femenino , Proteínas de Unión al GTP/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Hormonas Esteroides Gonadales/farmacología , Gónadas/metabolismo , Sustancias de Crecimiento/farmacología , Humanos , Masculino , Sistemas de Lectura Abierta , Especificidad de Órganos , Empalme del ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Receptores de Gonadotropina/biosíntesis , Receptores de Gonadotropina/clasificación , Receptores de Gonadotropina/fisiología , Ovinos , PorcinosRESUMEN
In a previous study we reported that ovaries from bovine fetuses, which consist mainly of preantral follicles with few antral follicles, are weakly responsive to gonadotropins (FSH and LH). Insulin-like growth factor-I (IGF-I) is known to enhance gonadotropin responsiveness in vitro, but there is a lack of consistent data on the involvement of IGF-I, FSH, and LH during early stages of folliculogenesis in cattle. In the study reported here, we assessed autoradiographically the ontogeny of 125I-gonadotropin and 125I-IGF-I binding activities during preantral and early antral stages in cattle. Follicular growth was initiated around Day 180 of gestation in fetuses. The density of 125I-FSH binding was high in granulosa cells from primary (mean +/- SEM 10.5 +/- 0.7 grains/cell, 0.05-mm diam.) and secondary follicles (10.8 +/- 0.8 to 13.6 +/- 1.2 grains/cell, 0.06-0.15 mm) but increased significantly (p < 0.05) in early antral follicles (18.2 +/- 1.1 grains/cell, 0.16-3.0 mm). Specific 125I-IGF-I binding levels were low in granulosa cells from preantral follicles, averaging 2.5 +/- 0.6-3.1 +/- 0.9 grains/cell. However, after antrum formation, the density of 125I-IGF-I binding increased significantly (p < 0.05) with follicular diameter in granulosa cells and was 5.7 +/- 0.7 and 9.1 +/- 0.6 grains/cell for antral I (0.16-0.5 mm) and antral II (0.6-3.0 mm) follicles, respectively. 125I-FSH and 125I-IGF-I binding densities were low in theca cells from preantral and early antral follicles as well as in the interstitial tissue and granulosa cells from atretic follicles.(ABSTRACT TRUNCATED AT 250 WORDS)