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Proietto S, Cortasa SA, Schmidt AR, Corso MC, Inserra PIF, Di Giorgio NP, Lux-Lantos V, Vitullo AD, Halperin J, Dorfman VB. Estradiol affects the expression of essential molecular factors involved in luteinizing hormone secretion in the plains vizcacha. Gen Comp Endocrinol 2025; 360:114642. [PMID: 39551248 DOI: 10.1016/j.ygcen.2024.114642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2024] [Revised: 11/07/2024] [Accepted: 11/12/2024] [Indexed: 11/19/2024]
Abstract
The plains vizcacha is a rodent that shows reactivation of the hypothalamic-pituitary-ovary (HPO) axis activity at mid-gestation. This process is enabled by the secretion of hypothalamic gonadotropin-releasing hormone (GnRH) at mid-gestation, followed by follicle-stimulating hormone (FSH) and luteinizing hormone (LH) secretion. However, a decrease in the pituitary GnRH receptor (GnRHR) expression is concomitantly determined. Moreover, an increment in the pituitary expression of estrogen receptor alpha (ERα) has been determined. This work aimed to study the impact of estradiol (E2) on GnRHR expression, the transcription factors early growth response protein-1 (Egr-1) and steroidogenic factor-1 (Sf-1), as well as on LH secretion. Three experimental approaches were performed: a physiological one with pregnant plains vizcachas, an in vivo approach with ovariectomized (OVX) animals treated with E2 (OVX + E2), and an ex vivo approach using pituitary glands exposed to a combination of GnRH and E2. Significant increased pituitary expression of Sf-1 and Egr-1 was determined at mid-gestation. Ovariectomy significantly increased adenohypophyseal expression levels of GnRHR, Egr-1, and Sf-1, as well as LH secretion. Then, OVX + E2 showed similar levels to SHAM. Adenohypophyses exposed to GnRH showed induced GnRHR, Egr-1, and Sf-1 expression, and LH secretion, while GnRH + E2 reverted these changes. The mid-gestation pituitary GnRHR decrease may result from the combination of increased E2 and GnRH secretion. Nevertheless, the increased expression of Egr-1 and Sf-1 at mid-gestation, together with LH release, suggests the tightly and complex regulatory system that takes place at mid-gestation, enabling a new progesterone surge that successfully carries the pregnancy to term. NEW & NOTEWORTHY: A significant increment of Sf-1 and Egr-1 at the pituitary of mid-gestating plains vizcachas was determined. Moreover, E2 reverted GnRHR, Egr-1, Sf-1, and LH increase in ovariectomized vizcachas' pituitaries and ex vivo pituitaries exposed to GnRH. The decrease of the pituitary GnRHR at mid-gestation may result from the increased E2 and GnRH levels. A tightly and complex regulatory system may take place at mid-gestation enabling a new surge of progesterone that carries pregnancy to term.
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Affiliation(s)
- Sofía Proietto
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Hidalgo 775 6to piso, C1405BCK Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Ciudad Autónoma de Buenos Aires, Argentina
| | - Santiago Andrés Cortasa
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Hidalgo 775 6to piso, C1405BCK Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Ciudad Autónoma de Buenos Aires, Argentina
| | - Alejandro Raúl Schmidt
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Hidalgo 775 6to piso, C1405BCK Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Ciudad Autónoma de Buenos Aires, Argentina
| | - María Clara Corso
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Hidalgo 775 6to piso, C1405BCK Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Ciudad Autónoma de Buenos Aires, Argentina
| | - Pablo Ignacio Felipe Inserra
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Hidalgo 775 6to piso, C1405BCK Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Ciudad Autónoma de Buenos Aires, Argentina
| | - Noelia Paula Di Giorgio
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IByME) - CONICET, Vuelta de Obligado 2490, C1428ADL Ciudad Autónoma de Buenos Aires, Argentina
| | - Victoria Lux-Lantos
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IByME) - CONICET, Vuelta de Obligado 2490, C1428ADL Ciudad Autónoma de Buenos Aires, Argentina
| | - Alfredo Daniel Vitullo
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Hidalgo 775 6to piso, C1405BCK Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Ciudad Autónoma de Buenos Aires, Argentina
| | - Julia Halperin
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Hidalgo 775 6to piso, C1405BCK Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Ciudad Autónoma de Buenos Aires, Argentina
| | - Verónica Berta Dorfman
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Hidalgo 775 6to piso, C1405BCK Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB Ciudad Autónoma de Buenos Aires, Argentina.
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Santos LC, Dos Anjos Cordeiro JM, da Silva Santana L, Barbosa EM, Santos BR, Mendonça LD, Cunha MCDSG, Machado WM, Santana LR, Kersul MG, Henriques PC, Lopes RA, Snoeck PPDN, Szawka RE, Silva JF. Kisspeptin treatment reverses high prolactin levels and improves gonadal function in hypothyroid male rats. Sci Rep 2023; 13:16819. [PMID: 37798396 PMCID: PMC10556046 DOI: 10.1038/s41598-023-44056-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 10/03/2023] [Indexed: 10/07/2023] Open
Abstract
We evaluated whether the administration of kisspeptin-10 (Kp10) is capable of restoring gonadal function in hypothyroid male rats. Hypothyroidism was induced with 6-propyl-2-thiouracil (PTU) for three months. In the last month, half of the hypothyroid animals were treated with Kp10. Hypothyroidism reduced testicular and sex gland mass, decreased the proliferation of the seminiferous epithelium, and compromised sperm morphology, motility, and vigor. A decrease in plasma LH and testosterone levels and an increase in prolactin secretion were observed in the hypothyroid rats. Hypothyroidism reduced Kiss1 and Kiss1r protein and gene expression and Star and Cyp11a1 mRNA levels in the testis. Furthermore, it reduced Lhb, Prl, and Drd2 and increased Tshb and Gnrhr expression in the pituitary. In the hypothalamus, hypothyroidism increased Pdyn and Kiss1r while reducing Gnrh1. Kp10 treatment in hypothyroid rats restored testicular and seminal vesicle morphology, improved sperm morphology and motility, reversed high prolactin levels, and increased LH and testosterone levels. In addition, Kp10 increased testicular expression of Kiss1, Kiss1r, Fshr, and Nr5a1 and pituitary Kiss1 expression. Our findings describe the inhibitory effects of hypothyroidism on the male gonadal axis and sperm quality and demonstrate that Kp10 treatment reverses high prolactin levels and improves gonadal function and sperm quality in hypothyroid rats.
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Affiliation(s)
- Luciano Cardoso Santos
- Centro de Microscopia Eletronica, Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - Jeane Martinha Dos Anjos Cordeiro
- Centro de Microscopia Eletronica, Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - Larissa da Silva Santana
- Centro de Microscopia Eletronica, Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - Erikles Macêdo Barbosa
- Centro de Microscopia Eletronica, Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - Bianca Reis Santos
- Centro de Microscopia Eletronica, Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - Letícia Dias Mendonça
- Centro de Microscopia Eletronica, Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - Maria Clara da Silva Galrão Cunha
- Centro de Microscopia Eletronica, Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - William Morais Machado
- Laboratorio de Reprodução Animal, Departamento de Ciencias Agrarias e Ambientais, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - Larissa Rodrigues Santana
- Laboratorio de Reprodução Animal, Departamento de Ciencias Agrarias e Ambientais, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - Maíra Guimarães Kersul
- Laboratorio de Reprodução Animal, Departamento de Ciencias Agrarias e Ambientais, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - Patrícia Costa Henriques
- Laboratorio de Endocrinologia e Metabolismo, Departamento de Fisiologia e Biofisica, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Roberta Araújo Lopes
- Laboratorio de Endocrinologia e Metabolismo, Departamento de Fisiologia e Biofisica, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Paola Pereira das Neves Snoeck
- Laboratorio de Reprodução Animal, Departamento de Ciencias Agrarias e Ambientais, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil
| | - Raphael Escorsim Szawka
- Laboratorio de Endocrinologia e Metabolismo, Departamento de Fisiologia e Biofisica, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Juneo Freitas Silva
- Centro de Microscopia Eletronica, Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, Campus Soane Nazare de Andrade, Ilheus, 45662-900, Brazil.
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Schang G, Ongaro L, Brûlé E, Zhou X, Wang Y, Boehm U, Ruf-Zamojski F, Zamojski M, Mendelev N, Seenarine N, Amper MA, Nair V, Ge Y, Sealfon SC, Bernard DJ. Transcription factor GATA2 may potentiate follicle-stimulating hormone production in mice via induction of the BMP antagonist gremlin in gonadotrope cells. J Biol Chem 2022; 298:102072. [PMID: 35643321 PMCID: PMC9251782 DOI: 10.1016/j.jbc.2022.102072] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 05/15/2022] [Accepted: 05/22/2022] [Indexed: 11/29/2022] Open
Abstract
Mammalian reproduction depends on the gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone, which are secreted by pituitary gonadotrope cells. The zinc-finger transcription factor GATA2 was previously implicated in FSH production in male mice; however, its mechanisms of action and role in females were not determined. To directly address GATA2 function in gonadotropes, we generated and analyzed gonadotrope-specific Gata2 KO mice using the Cre-lox system. We found that while conditional KO (cKO) males exhibited ∼50% reductions in serum FSH levels and pituitary FSHβ subunit (Fshb) expression relative to controls, FSH production was apparently normal in cKO females. In addition, RNA-seq analysis of purified gonadotropes from control and cKO males revealed a profound decrease in expression of gremlin (Grem1), a bone morphogenetic protein (BMP) antagonist. We show Grem1 was expressed in gonadotropes, but not other cell lineages, in the adult male mouse pituitary. Furthermore, Gata2, Grem1, and Fshb mRNA levels were significantly higher in the pituitaries of WT males relative to females but decreased in males treated with estradiol and increased following ovariectomy in control but not cKO females. Finally, we found that recombinant gremlin stimulated Fshb expression in pituitary cultures from WT mice. Collectively, the data suggest that GATA2 promotes Grem1 expression in gonadotropes and that the gremlin protein potentiates FSH production. The mechanisms of gremlin action have not yet been established but may involve attenuation of BMP binding to activin type II receptors in gonadotropes, facilitating induction of Fshb transcription by activins or related ligands.
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Affiliation(s)
- Gauthier Schang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Luisina Ongaro
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Emilie Brûlé
- Department of Anatomy and Cell Biology, McGill University, Montréal, Québec, Canada
| | - Xiang Zhou
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Ying Wang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Ulrich Boehm
- Department of Experimental Pharmacology, Center for Molecular Signaling, Saarland University School of Medicine, Homburg, Germany
| | - Frederique Ruf-Zamojski
- Department of Neurology, Center for Advanced Research on Diagnostic Assays, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Michel Zamojski
- Department of Neurology, Center for Advanced Research on Diagnostic Assays, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Natalia Mendelev
- Department of Neurology, Center for Advanced Research on Diagnostic Assays, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Nitish Seenarine
- Department of Neurology, Center for Advanced Research on Diagnostic Assays, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Mary Anne Amper
- Department of Neurology, Center for Advanced Research on Diagnostic Assays, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Venugopalan Nair
- Department of Neurology, Center for Advanced Research on Diagnostic Assays, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Yongchao Ge
- Department of Neurology, Center for Advanced Research on Diagnostic Assays, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Stuart C Sealfon
- Department of Neurology, Center for Advanced Research on Diagnostic Assays, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Daniel J Bernard
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, Québec, Canada.
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Mohamed AR, Naval-Sanchez M, Menzies M, Evans B, King H, Reverter A, Kijas JW. Leveraging transcriptome and epigenome landscapes to infer regulatory networks during the onset of sexual maturation. BMC Genomics 2022; 23:413. [PMID: 35650521 PMCID: PMC9158274 DOI: 10.1186/s12864-022-08514-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 03/29/2022] [Indexed: 12/03/2022] Open
Abstract
Background Despite sexual development being ubiquitous to vertebrates, the molecular mechanisms underpinning this fundamental transition remain largely undocumented in many organisms. We designed a time course experiment that successfully sampled the period when Atlantic salmon commence their trajectory towards sexual maturation. Results Through deep RNA sequencing, we discovered key genes and pathways associated with maturation in the pituitary-ovarian axis. Analyzing DNA methylomes revealed a bias towards hypermethylation in ovary that implicated maturation-related genes. Co-analysis of DNA methylome and gene expression changes revealed chromatin remodeling genes and key transcription factors were both significantly hypermethylated and upregulated in the ovary during the onset of maturation. We also observed changes in chromatin state landscapes that were strongly correlated with fundamental remodeling of gene expression in liver. Finally, a multiomic integrated analysis revealed regulatory networks and identified hub genes including TRIM25 gene (encoding the estrogen-responsive finger protein) as a putative key regulator in the pituitary that underwent a 60-fold change in connectivity during the transition to maturation. Conclusion The study successfully documented transcriptome and epigenome changes that involved key genes and pathways acting in the pituitary – ovarian axis. Using a Systems Biology approach, we identified hub genes and their associated networks deemed crucial for onset of maturation. The results provide a comprehensive view of the spatiotemporal changes involved in a complex trait and opens the door to future efforts aiming to manipulate puberty in an economically important aquaculture species. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08514-8.
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Lalonde-Larue A, Boyer A, Dos Santos EC, Boerboom D, Bernard DJ, Zamberlam G. The Hippo Pathway Effectors YAP and TAZ Regulate LH Release by Pituitary Gonadotrope Cells in Mice. Endocrinology 2022; 163:bqab238. [PMID: 34905605 PMCID: PMC8670590 DOI: 10.1210/endocr/bqab238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Indexed: 01/08/2023]
Abstract
The Hippo transcriptional coactivators YAP and TAZ exert critical roles in morphogenesis, organ size determination and tumorigenesis in many tissues. Although Hippo kinase cascade activity was recently reported in the anterior pituitary gland in mice, the role of the Hippo effectors in regulating gonadotropin production remains unknown. The objective of this study was therefore to characterize the roles of YAP and TAZ in gonadotropin synthesis and secretion. Using a conditional gene targeting approach (cKO), we found that gonadotrope-specific inactivation of Yap and Taz resulted in increased circulating levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in adult male mice, along with increased testosterone levels and testis weight. Female cKO mice had increased circulating LH (but not FSH) levels, which were associated with a hyperfertility phenotype characterized by higher ovulation rates and larger litter sizes. Unexpectedly, the loss of YAP/TAZ did not appear to affect the expression of gonadotropin subunit genes, yet both basal and GnRH-induced LH secretion were increased in cultured pituitary cells from cKO mice. Likewise, pharmacologic inhibition of YAP binding to the TEAD family of transcription factors increased both basal and GnRH-induced LH secretion in LβT2 gonadotrope-like cells in vitro without affecting Lhb expression. Conversely, mRNA levels of ChgA and SgII, which encode key secretory granule cargo proteins, were decreased following pharmacologic inhibition of YAP/TAZ, suggesting a mechanism whereby YAP/TAZ regulate the LH secretion machinery in gonadotrope cells. Together, these findings represent the first evidence that Hippo signaling may play a role in regulating pituitary LH secretion.
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Affiliation(s)
- Ariane Lalonde-Larue
- Centre de recherche en reproduction et fertilité (CRRF), Faculté de médecine Vétérinaire, Université de Montréal, Montréal, Quebec J2S 7C6, Canada
| | - Alexandre Boyer
- Centre de recherche en reproduction et fertilité (CRRF), Faculté de médecine Vétérinaire, Université de Montréal, Montréal, Quebec J2S 7C6, Canada
| | - Esdras Corrêa Dos Santos
- Centre de recherche en reproduction et fertilité (CRRF), Faculté de médecine Vétérinaire, Université de Montréal, Montréal, Quebec J2S 7C6, Canada
| | - Derek Boerboom
- Centre de recherche en reproduction et fertilité (CRRF), Faculté de médecine Vétérinaire, Université de Montréal, Montréal, Quebec J2S 7C6, Canada
| | - Daniel J Bernard
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Gustavo Zamberlam
- Centre de recherche en reproduction et fertilité (CRRF), Faculté de médecine Vétérinaire, Université de Montréal, Montréal, Quebec J2S 7C6, Canada
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Zmijewska A, Czelejewska W, Waszkiewicz EM, Gajewska A, Okrasa S, Franczak A. Transcriptomic analysis of the porcine anterior pituitary gland during the peri-implantation period. Reprod Domest Anim 2020; 55:1434-1445. [PMID: 32745313 DOI: 10.1111/rda.13794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/28/2020] [Indexed: 12/21/2022]
Abstract
The peri-implantation period is controlled by signals originating from hypothalamic-pituitary-ovarian axis, uterus and developing embryos. The transcriptomic activity of the anterior pituitary gland may be important for the control of the peri-implantation period. The aim of this study was to determine the alternations in the transcriptomic profile of porcine anterior pituitary gland during the peri-implantation period (days 15-16 of pregnancy) in comparison with established for the respective days of the oestrous cycle. Analysis using a microarray approach indicated that the 651 genes (fold-change ˂1.2; p ≤ .05) were differentially expressed (DEGs) in the anterior pituitary of pigs during the peri-implantation period when compared to cyclic females. Of these DEGs, 404 were upregulated and 247 downregulated. Analysis of occurred relationships among DEGs revealed that some of them are involved in steroid-response and oestrogen synthesis, FSH secretion, immune response, PPAR signalling pathway and the potential for DNA methylation. In conclusion, the altered transcriptomic profile of the porcine pituitary gland in pigs during the peri-implantation period indicates the role of embryos presence in the creation of transcriptomic activity of the pituitary gland in pigs.
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Affiliation(s)
- Agata Zmijewska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Wioleta Czelejewska
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Ewa M Waszkiewicz
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Alina Gajewska
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Science, Jablonna, Poland
| | - Stanislaw Okrasa
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Anita Franczak
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
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Emura N, Wang CM, Yang WH, Yang WH. Steroidogenic Factor 1 (NR5A1) Activates ATF3 Transcriptional Activity. Int J Mol Sci 2020; 21:ijms21041429. [PMID: 32093223 PMCID: PMC7073147 DOI: 10.3390/ijms21041429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 11/16/2022] Open
Abstract
Steroidogenic Factor 1 (SF-1/NR5A1), an orphan nuclear receptor, is important for sexual differentiation and the development of multiple endocrine organs, as well as cell proliferation in cancer cells. Activating transcription factor 3 (ATF3) is a transcriptional repressor, and its expression is rapidly induced by DNA damage and oncogenic stimuli. Since both NR5A1 and ATF3 can regulate and cooperate with several transcription factors, we hypothesized that NR5A1 may interact with ATF3 and plays a functional role in cancer development. First, we found that NR5A1 physically interacts with ATF3. We further demonstrated that ATF3 expression is up-regulated by NR5A1. Moreover, the promoter activity of the ATF3 is activated by NR5A1 in a dose-dependent manner in several cell lines. By mapping the ATF3 promoter as well as the site-directed mutagenesis analysis, we provide evidence that NR5A1 response elements (-695 bp and -665 bp) are required for ATF3 expression by NR5A1. It is well known that the transcriptional activities of NR5A1 are modulated by post-translational modifications, such as small ubiquitin-related modifier (SUMO) modification and phosphorylation. Notably, we found that both SUMOylation and phosphorylation of NR5A1 play roles, at least in part, for NR5A1-mediated ATF3 expression. Overall, our results provide the first evidence of a novel relationship between NR5A1 and ATF3.
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Affiliation(s)
- Natsuko Emura
- The United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan;
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA 31404, USA; (C.-M.W.); (W.H.Y.)
| | - Chiung-Min Wang
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA 31404, USA; (C.-M.W.); (W.H.Y.)
| | - William Harry Yang
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA 31404, USA; (C.-M.W.); (W.H.Y.)
| | - Wei-Hsiung Yang
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA 31404, USA; (C.-M.W.); (W.H.Y.)
- Correspondence: ; Tel.: +1-912-721-8203; Fax: +1-912-721-8268
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8
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Clay CM, Cherrington BD, Navratil AM. Plasticity of Anterior Pituitary Gonadotrope Cells Facilitates the Pre-Ovulatory LH Surge. Front Endocrinol (Lausanne) 2020; 11:616053. [PMID: 33613451 PMCID: PMC7890248 DOI: 10.3389/fendo.2020.616053] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 12/15/2020] [Indexed: 01/04/2023] Open
Abstract
Gonadotropes cells located in the anterior pituitary gland are critical for reproductive fitness. A rapid surge in the serum concentration of luteinizing hormone (LH) secreted by anterior pituitary gonadotropes is essential for stimulating ovulation and is thus required for a successful pregnancy. To meet the requirements to mount the LH surge, gonadotrope cells display plasticity at the cellular, molecular and morphological level. First, gonadotrope cells heighten their sensitivity to an increasing frequency of hypothalamic GnRH pulses by dynamically elevating the expression of the GnRH receptor (GnRHR). Following ligand binding, GnRH initiates highly organized intracellular signaling cascades that ultimately promote the synthesis of LH and the trafficking of LH vesicles to the cell periphery. Lastly, gonadotrope cells display morphological plasticity, where there is directed mobilization of cytoskeletal processes towards vascular elements to facilitate rapid LH secretion into peripheral circulation. This mini review discusses the functional and organizational plasticity in gonadotrope cells including changes in sensitivity to GnRH, composition of the GnRHR signaling platform within the plasma membrane, and changes in cellular morphology. Ultimately, multimodal plasticity changes elicited by gonadotropes are critical for the generation of the LH surge, which is required for ovulation.
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Affiliation(s)
- Colin M. Clay
- Department of Biomedical Science, Colorado State University, Fort Collins, CO, United States
| | - Brian D. Cherrington
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, United States
| | - Amy M. Navratil
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, United States
- *Correspondence: Amy M. Navratil,
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9
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Janjic MM, Prévide RM, Fletcher PA, Sherman A, Smiljanic K, Abebe D, Bjelobaba I, Stojilkovic SS. Divergent expression patterns of pituitary gonadotropin subunit and GnRH receptor genes to continuous GnRH in vitro and in vivo. Sci Rep 2019; 9:20098. [PMID: 31882740 PMCID: PMC6934515 DOI: 10.1038/s41598-019-56480-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/12/2019] [Indexed: 12/22/2022] Open
Abstract
Continuous, as opposed to pulsatile, delivery of hypothalamic gonadotropin-releasing hormone (GnRH) leads to a marked decrease in secretion of pituitary gonadotropins LH and FSH and impairment of reproductive function. Here we studied the expression profile of gonadotropin subunit and GnRH receptor genes in rat pituitary in vitro and in vivo to clarify their expression profiles in the absence and continuous presence of GnRH. Culturing of pituitary cells in GnRH-free conditions downregulated Fshb, Cga, and Gnrhr expression, whereas continuous treatment with GnRH agonists upregulated Cga expression progressively and Gnrhr and Fshb expression transiently, accompanied by a prolonged blockade of Fshb but not Gnrhr expression. In contrast, Lhb expression was relatively insensitive to loss of endogenous GnRH and continuous treatment with GnRH, probably reflecting the status of Egr1 and Nr5a1 expression. Similar patterns of responses were observed in vivo after administration of a GnRH agonist. However, continuous treatment with GnRH stimulated LH secretion in vitro and in vivo, leading to decrease in LH cell content despite high basal Lhb expression. These data suggest that blockade of Fshb expression and depletion of the LH secretory pool are two major factors accounting for weakening of the gonadotroph secretory function during continuous GnRH treatment.
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Affiliation(s)
- Marija M Janjic
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
- Institute for Biological Research Sinisa Stankovic - National Institute of Republic of Serbia, University of Belgrade, 11000, Belgrade, Serbia
| | - Rafael M Prévide
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Patrick A Fletcher
- Laboratory of Biological Modeling, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Arthur Sherman
- Laboratory of Biological Modeling, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Kosara Smiljanic
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Daniel Abebe
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ivana Bjelobaba
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
- Institute for Biological Research Sinisa Stankovic - National Institute of Republic of Serbia, University of Belgrade, 11000, Belgrade, Serbia
| | - Stanko S Stojilkovic
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA.
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10
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Liu S, Yan L, Zhou X, Chen C, Wang D, Yuan G. Delayed-onset adrenal hypoplasia congenita and hypogonadotropic hypogonadism caused by a novel mutation in DAX1. J Int Med Res 2019; 48:300060519882151. [PMID: 31642359 PMCID: PMC7605007 DOI: 10.1177/0300060519882151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In this study, we described a male who presented with delayed-onset adrenal
hypoplasia congenita (AHC) and mild hypogonadotropic hypogonadism (HHG) without
a relevant family history. A novel mutation in the DAX1
(dosage-sensitive sex reversal, congenital adrenal hypoplasia critical region on
the X chromosome, gene 1) gene was shown to cause X-linked AHC and HHG. Genetic
analysis revealed a novel nonsense mutation, c.154G > T (p.Glu52Term), in the
DAX1 gene. Molecular testing demonstrated that the milder
phenotype caused by this mutation was due to expression of a partially
functional, amino-truncated DAX1 protein generated from an
alternate in-frame translation start site (methionine at codon 83). This unusual
case revealed a potential mechanism for a novel mutation that resulted in an
unusual delayed-onset mild clinical phenotype. It expands the spectrum of
adrenal hypoplasia congenita and hypogonadotropic hypogonadism.
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Affiliation(s)
- Siyue Liu
- Department of Internal Medicine, Tongji Hospital, Huazhong
University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Libin Yan
- Department of Urology, Tongji Hospital, Huazhong University of
Science and Technology, Wuhan, Hubei, P.R. China
| | - Xinrong Zhou
- Department of Internal Medicine, Tongji Hospital, Huazhong
University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Chen Chen
- Molecular Diagnostic Laboratory, Tongji Hospital, Huazhong
University of Science and Technology, Wuhan, Hubei, China
| | - Daowen Wang
- Department of Internal Medicine, Tongji Hospital, Huazhong
University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Gang Yuan
- Department of Internal Medicine, Tongji Hospital, Huazhong
University of Science and Technology, Wuhan, Hubei, P.R. China
- Gang Yuan, Department of Internal Medicine,
Tongji Hospital, Tongji Medical College, Huazhong University of Science &
Technology, Wuhan 430030, China.
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11
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Rudnizky S, Khamis H, Malik O, Squires AH, Meller A, Melamed P, Kaplan A. Single-molecule DNA unzipping reveals asymmetric modulation of a transcription factor by its binding site sequence and context. Nucleic Acids Res 2019; 46:1513-1524. [PMID: 29253225 PMCID: PMC5815098 DOI: 10.1093/nar/gkx1252] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 12/11/2017] [Indexed: 12/31/2022] Open
Abstract
Most functional transcription factor (TF) binding sites deviate from their ‘consensus’ recognition motif, although their sites and flanking sequences are often conserved across species. Here, we used single-molecule DNA unzipping with optical tweezers to study how Egr-1, a TF harboring three zinc fingers (ZF1, ZF2 and ZF3), is modulated by the sequence and context of its functional sites in the Lhb gene promoter. We find that both the core 9 bp bound to Egr-1 in each of the sites, and the base pairs flanking them, modulate the affinity and structure of the protein–DNA complex. The effect of the flanking sequences is asymmetric, with a stronger effect for the sequence flanking ZF3. Characterization of the dissociation time of Egr-1 revealed that a local, mechanical perturbation of the interactions of ZF3 destabilizes the complex more effectively than a perturbation of the ZF1 interactions. Our results reveal a novel role for ZF3 in the interaction of Egr-1 with other proteins and the DNA, providing insight on the regulation of Lhb and other genes by Egr-1. Moreover, our findings reveal the potential of small changes in DNA sequence to alter transcriptional regulation, and may shed light on the organization of regulatory elements at promoters.
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Affiliation(s)
- Sergei Rudnizky
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Hadeel Khamis
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Faculty of Physics, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Omri Malik
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Allison H Squires
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Amit Meller
- Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.,Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Philippa Melamed
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Ariel Kaplan
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel.,Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel
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12
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Sharma S, Chaube R. Molecular cloning and characterization of secretogranin II in the catfish Heteropneustes fossilis: Sex and seasonal brain regional variations and its gonadotropin regulation. Comp Biochem Physiol A Mol Integr Physiol 2019; 232:13-27. [DOI: 10.1016/j.cbpa.2019.02.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 02/18/2019] [Accepted: 02/18/2019] [Indexed: 12/11/2022]
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13
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Acevedo-Rodriguez A, Kauffman AS, Cherrington BD, Borges CS, Roepke TA, Laconi M. Emerging insights into hypothalamic-pituitary-gonadal axis regulation and interaction with stress signalling. J Neuroendocrinol 2018; 30. [PMID: 29524268 PMCID: PMC6129417 DOI: 10.1111/jne.12590] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Reproduction and fertility are regulated via hormones of the hypothalamic-pituitary-gonadal (HPG) axis. Control of this reproductive axis occurs at all levels, including the brain and pituitary, and allows for the promotion or inhibition of gonadal sex steroid secretion and function. In addition to guiding proper gonadal development and function, gonadal sex steroids also act in negative- and positive-feedback loops to regulate reproductive circuitry in the brain, including kisspeptin neurones, thereby modulating overall HPG axis status. Additional regulation is also provided by sex steroids made within the brain, including neuroprogestins. Furthermore, because reproduction and survival need to be coordinated and balanced, the HPG axis is able to modulate (and be modulated by) stress hormone signalling, including cortiscosterone, from the hypothalamic-pituitary-adrenal (HPA) axis. This review covers recent data related to the neural, hormonal and stress regulation of the HPG axis and emerging interactions between the HPG and HPA axes, focusing on actions at the level of the brain and pituitary.
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Affiliation(s)
- A Acevedo-Rodriguez
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - A S Kauffman
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, CA, USA
| | - B D Cherrington
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - C S Borges
- Department of Morphology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu, Brazil
| | - T A Roepke
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - M Laconi
- Laboratorio de Fisiopatología Ovárica, Instituto de Medicina y Biología Experimental de Cuyo (IMBECU - CONICET), Universidad Juan Agustín Maza, Mendoza, Argentina
- Facultad de Ciencias Veterinarias y Ambientales, Universidad Juan Agustín Maza, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad de Mendoza, Mendoza, Argentina
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14
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Coss D. Regulation of reproduction via tight control of gonadotropin hormone levels. Mol Cell Endocrinol 2018; 463:116-130. [PMID: 28342855 PMCID: PMC6457911 DOI: 10.1016/j.mce.2017.03.022] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/16/2017] [Accepted: 03/21/2017] [Indexed: 01/04/2023]
Abstract
Mammalian reproduction is controlled by the hypothalamic-pituitary-gonadal axis. GnRH from the hypothalamus regulates synthesis and secretion of gonadotropins, LH and FSH, which then control steroidogenesis and gametogenesis. In females, serum LH and FSH levels exhibit rhythmic changes throughout the menstrual or estrous cycle that are correlated with pulse frequency of GnRH. Lack of gonadotropins leads to infertility or amenorrhea. Dysfunctions in the tightly controlled ratio due to levels slightly outside the normal range occur in a larger number of women and are correlated with polycystic ovaries and premature ovarian failure. Since the etiology of these disorders is largely unknown, studies in cell and mouse models may provide novel candidates for investigations in human population. Hence, understanding the mechanisms whereby GnRH regulates gonadotropin hormone levels will provide insight into the physiology and pathophysiology of the reproductive system. This review discusses recent advances in our understanding of GnRH regulation of gonadotropin synthesis.
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Affiliation(s)
- Djurdjica Coss
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA 92521, United States.
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15
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Stamatiades GA, Kaiser UB. Gonadotropin regulation by pulsatile GnRH: Signaling and gene expression. Mol Cell Endocrinol 2018; 463:131-141. [PMID: 29102564 PMCID: PMC5812824 DOI: 10.1016/j.mce.2017.10.015] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/27/2017] [Accepted: 10/27/2017] [Indexed: 12/12/2022]
Abstract
The precise orchestration of hormonal regulation at all levels of the hypothalamic-pituitary-gonadal axis is essential for normal reproductive function and fertility. The pulsatile secretion of hypothalamic gonadotropin-releasing hormone (GnRH) stimulates the synthesis and release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) by pituitary gonadotropes. GnRH acts by binding to its high affinity seven-transmembrane receptor (GnRHR) on the cell surface of anterior pituitary gonadotropes. Different signaling cascades and transcriptional mechanisms are activated, depending on the variation in GnRH pulse frequency, to stimulate the synthesis and release of FSH and LH. While changes in GnRH pulse frequency may explain some of the differential regulation of FSH and LH, other factors, such as activin, inhibin and sex steroids, also contribute to gonadotropin production. In this review, we focus on the transcriptional regulation of the gonadotropin subunit genes and the signaling pathways activated by pulsatile GnRH.
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Affiliation(s)
- George A Stamatiades
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, United States
| | - Ursula B Kaiser
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, United States.
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16
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Melamed P, Haj M, Yosefzon Y, Rudnizky S, Wijeweera A, Pnueli L, Kaplan A. Multifaceted Targeting of the Chromatin Mediates Gonadotropin-Releasing Hormone Effects on Gene Expression in the Gonadotrope. Front Endocrinol (Lausanne) 2018; 9:58. [PMID: 29535683 PMCID: PMC5835078 DOI: 10.3389/fendo.2018.00058] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) stimulates the expression of multiple genes in the pituitary gonadotropes, most notably to induce synthesis of the gonadotropins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH), but also to ensure the appropriate functioning of these cells at the center of the mammalian reproductive endocrine axis. Aside from the activation of gene-specific transcription factors, GnRH stimulates through its membrane-bound receptor, alterations in the chromatin that facilitate transcription of its target genes. These include changes in the histone and DNA modifications, nucleosome positioning, and chromatin packaging at the regulatory regions of each gene. The requirements for each of these events vary according to the DNA sequence which determines the basal chromatin packaging at the regulatory regions. Despite considerable progress in this field in recent years, we are only beginning to understand some of the complexities involved in the role and regulation of this chromatin structure, including new modifications, extensive cross talk, histone variants, and the actions of distal enhancers and non-coding RNAs. This short review aims to integrate the latest findings on GnRH-induced alterations in the chromatin of its target genes, which indicate multiple and diverse actions. Understanding these processes is illuminating not only in the context of the activation of these hormones during the reproductive life span but may also reveal how aberrant epigenetic regulation of these genes leads to sub-fertility.
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Affiliation(s)
- Philippa Melamed
- Faculty of Biology, Technion—Israel Institute of Technology, Haifa, Israel
- *Correspondence: Philippa Melamed,
| | - Majd Haj
- Faculty of Biology, Technion—Israel Institute of Technology, Haifa, Israel
| | - Yahav Yosefzon
- Faculty of Biology, Technion—Israel Institute of Technology, Haifa, Israel
| | - Sergei Rudnizky
- Faculty of Biology, Technion—Israel Institute of Technology, Haifa, Israel
| | - Andrea Wijeweera
- Faculty of Biology, Technion—Israel Institute of Technology, Haifa, Israel
| | - Lilach Pnueli
- Faculty of Biology, Technion—Israel Institute of Technology, Haifa, Israel
| | - Ariel Kaplan
- Faculty of Biology, Technion—Israel Institute of Technology, Haifa, Israel
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17
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Xia JF, Inagaki Y, Zhang JF, Wang L, Song PP. Chinese medicine as complementary therapy for female infertility. Chin J Integr Med 2016; 23:245-252. [PMID: 27484764 DOI: 10.1007/s11655-016-2510-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Indexed: 11/26/2022]
Abstract
Chinese medicine (CM) has been used in clinical treatment for thousands of years in China, Japan, Korea, and other countries. CM is at present attracting many attentions around the world for reproductive health care and disease prevention, including treatment of female infertility. This review focuses on the CM treatment for female infertility patients, and supplies a summary on the efficacy, safety, and mechanism of some Chinese herbal medicines, herbal medicine-derived active compounds, and acupuncture. A large number of researches have reported that CM could alleviate or even cure female infertility by regulating hormone, improving reproductive outcome of in vivo fertilization, affecting embryonic implantation, curing polycystic ovarian syndrome, endometriosis, pelvic inflammatory disease, relieving mental stress, and regulating immune system. Meanwhile, a few studies claimed that there was little adverse reaction of CM in randomized controlled trials. However, up to present there is a lack of adequate evidences with molecular mechanistic researches and randomized controlled trials to prove the CM as an effective and safe treatment for infertility. Thus, utility of CM as a complementary medicine will be a feasible method to improve the outcome of female infertility treatment.
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Affiliation(s)
- Ju-Feng Xia
- Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Yoshinori Inagaki
- Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Jian-Feng Zhang
- Laboratory for Reproductive Immunology, Hospital & Institute of Obstetrics and Gynecology, Fudan University Shanghai Medical College, Shanghai, 200011, China
- Academy of Integrated Traditional Chinese and Mordern Medicine of Fudan University, Shanghai, 200011, China
| | - Ling Wang
- Laboratory for Reproductive Immunology, Hospital & Institute of Obstetrics and Gynecology, Fudan University Shanghai Medical College, Shanghai, 200011, China
- Academy of Integrated Traditional Chinese and Mordern Medicine of Fudan University, Shanghai, 200011, China
| | - Pei-Pei Song
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-shi, 227-8561, Japan.
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18
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Barda S, Yogev L, Paz G, Yavetz H, Hauser R, Breitbart H, Kleiman SE. New insights into the role of the Brdt protein in the regulation of development and spermatogenesis in the mouse. Gene Expr Patterns 2016; 20:130-7. [DOI: 10.1016/j.gep.2016.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 03/11/2016] [Accepted: 03/14/2016] [Indexed: 12/01/2022]
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19
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Thompson IR, Ciccone NA, Zhou Q, Xu S, Khogeer A, Carroll RS, Kaiser UB. GnRH Pulse Frequency Control of Fshb Gene Expression Is Mediated via ERK1/2 Regulation of ICER. Mol Endocrinol 2016; 30:348-60. [PMID: 26835742 DOI: 10.1210/me.2015-1222] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The pulsatile release of GnRH regulates the synthesis and secretion of pituitary FSH and LH. Two transcription factors, cAMP-response element-binding protein (CREB) and inducible cAMP early repressor (ICER), have been implicated in the regulation of rat Fshb gene expression. We previously showed that the protein kinase A pathway mediates GnRH-stimulated CREB activation. We hypothesized that CREB and ICER are activated by distinct signaling pathways in response to pulsatile GnRH to modulate Fshb gene expression, which is preferentially stimulated at low vs high pulse frequencies. In the LβT2 gonadotrope-derived cell line, GnRH stimulation increased ICER mRNA and protein. Blockade of ERK activation with mitogen-activated protein kinase kinase I/II (MEKI/II) inhibitors significantly attenuated GnRH induction of ICER mRNA and protein, whereas protein kinase C, calcium/calmodulin-dependent protein kinase II, and protein kinase A inhibitors had minimal effects. GnRH also stimulated ICER in primary mouse pituitary cultures, attenuated similarly by a MEKI/II inhibitor. In a perifusion paradigm, MEKI/II inhibition in LβT2 cells stimulated with pulsatile GnRH abrogated ICER induction at high GnRH pulse frequencies, with minimal effect at low frequencies. MEKI/II inhibition reduced GnRH stimulation of Fshb at high and low pulse frequencies, suggesting that the ERK pathway has additional effects on GnRH regulation of Fshb, beyond those mediated by ICER. Indeed, induction of the activating protein 1 proteins, cFos and cJun, positive modulators of Fshb transcription, by pulsatile GnRH was also abrogated by inhibition of the MEK/ERK signaling pathway. Collectively, these studies indicate that the signaling pathways mediating GnRH activation of CREB and ICER are distinct, contributing to the decoding of the pulsatile GnRH to regulate FSHβ expression.
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Affiliation(s)
- Iain R Thompson
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Nick A Ciccone
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Qiongjie Zhou
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Shuyun Xu
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Ahmad Khogeer
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Rona S Carroll
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Ursula B Kaiser
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
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20
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Johnston JD, Skene DJ. 60 YEARS OF NEUROENDOCRINOLOGY: Regulation of mammalian neuroendocrine physiology and rhythms by melatonin. J Endocrinol 2015; 226:T187-98. [PMID: 26101375 DOI: 10.1530/joe-15-0119] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/17/2015] [Indexed: 12/15/2022]
Abstract
The isolation of melatonin was first reported in 1958. Since the demonstration that pineal melatonin synthesis reflects both daily and seasonal time, melatonin has become a key element of chronobiology research. In mammals, pineal melatonin is essential for transducing day-length information into seasonal physiological responses. Due to its lipophilic nature, melatonin is able to cross the placenta and is believed to regulate multiple aspects of perinatal physiology. The endogenous daily melatonin rhythm is also likely to play a role in the maintenance of synchrony between circadian clocks throughout the adult body. Pharmacological doses of melatonin are effective in resetting circadian rhythms if taken at an appropriate time of day, and can acutely regulate factors such as body temperature and alertness, especially when taken during the day. Despite the extensive literature on melatonin physiology, some key questions remain unanswered. In particular, the amplitude of melatonin rhythms has been recently associated with diseases such as type 2 diabetes mellitus but understanding of the physiological significance of melatonin rhythm amplitude remains poorly understood.
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Affiliation(s)
- Jonathan D Johnston
- Faculty of Health and Medical SciencesUniversity of Surrey, Guildford, Surrey GU2 7XH, UK
| | - Debra J Skene
- Faculty of Health and Medical SciencesUniversity of Surrey, Guildford, Surrey GU2 7XH, UK
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21
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Xie H, Hoffmann HM, Meadows JD, Mayo SL, Trang C, Leming SS, Maruggi C, Davis SW, Larder R, Mellon PL. Homeodomain Proteins SIX3 and SIX6 Regulate Gonadotrope-specific Genes During Pituitary Development. Mol Endocrinol 2015; 29:842-55. [PMID: 25915183 PMCID: PMC4447639 DOI: 10.1210/me.2014-1279] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 04/20/2015] [Indexed: 12/15/2022] Open
Abstract
Sine oculis-related homeobox 3 (SIX3) and SIX6, 2 closely related homeodomain transcription factors, are involved in development of the mammalian neuroendocrine system and mutations of Six6 adversely affect fertility in mice. We show that both small interfering RNA knockdown in gonadotrope cell lines and knockout of Six6 in both embryonic and adult male mice (Six6 knockout) support roles for SIX3 and SIX6 in transcriptional regulation in gonadotrope gene expression and that SIX3 and SIX6 can functionally compensate for each other. Six3 and Six6 expression patterns in gonadotrope cell lines reflect the timing of the expression of pituitary markers they regulate. Six3 is expressed in an immature gonadotrope cell line and represses transcription of the early lineage-specific pituitary genes, GnRH receptor (GnRHR) and the common α-subunit (Cga), whereas Six6 is expressed in a mature gonadotrope cell line and represses the specific β-subunits of LH and FSH (LHb and FSHb) that are expressed later in development. We show that SIX6 repression requires interaction with transducin-like enhancer of split corepressor proteins and competition for DNA-binding sites with the transcriptional activator pituitary homeobox 1. Our studies also suggest that estradiol and circadian rhythm regulate pituitary expression of Six6 and Six3 in adult females but not in males. In summary, SIX3 and SIX6 play distinct but compensatory roles in regulating transcription of gonadotrope-specific genes as gonadotrope cells differentiate.
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Affiliation(s)
- Huimin Xie
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine (H.X., H.M.H., J.D.M., S.L.M., C.T., S.S.L., C.M., R.L., P.L.M.), University of California, San Diego, La Jolla, California 92093; and Department of Human Genetics (S.W.D.), University of Michigan, Ann Arbor, Michigan 48109
| | - Hanne M Hoffmann
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine (H.X., H.M.H., J.D.M., S.L.M., C.T., S.S.L., C.M., R.L., P.L.M.), University of California, San Diego, La Jolla, California 92093; and Department of Human Genetics (S.W.D.), University of Michigan, Ann Arbor, Michigan 48109
| | - Jason D Meadows
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine (H.X., H.M.H., J.D.M., S.L.M., C.T., S.S.L., C.M., R.L., P.L.M.), University of California, San Diego, La Jolla, California 92093; and Department of Human Genetics (S.W.D.), University of Michigan, Ann Arbor, Michigan 48109
| | - Susan L Mayo
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine (H.X., H.M.H., J.D.M., S.L.M., C.T., S.S.L., C.M., R.L., P.L.M.), University of California, San Diego, La Jolla, California 92093; and Department of Human Genetics (S.W.D.), University of Michigan, Ann Arbor, Michigan 48109
| | - Crystal Trang
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine (H.X., H.M.H., J.D.M., S.L.M., C.T., S.S.L., C.M., R.L., P.L.M.), University of California, San Diego, La Jolla, California 92093; and Department of Human Genetics (S.W.D.), University of Michigan, Ann Arbor, Michigan 48109
| | - Sunamita S Leming
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine (H.X., H.M.H., J.D.M., S.L.M., C.T., S.S.L., C.M., R.L., P.L.M.), University of California, San Diego, La Jolla, California 92093; and Department of Human Genetics (S.W.D.), University of Michigan, Ann Arbor, Michigan 48109
| | - Chiara Maruggi
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine (H.X., H.M.H., J.D.M., S.L.M., C.T., S.S.L., C.M., R.L., P.L.M.), University of California, San Diego, La Jolla, California 92093; and Department of Human Genetics (S.W.D.), University of Michigan, Ann Arbor, Michigan 48109
| | - Shannon W Davis
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine (H.X., H.M.H., J.D.M., S.L.M., C.T., S.S.L., C.M., R.L., P.L.M.), University of California, San Diego, La Jolla, California 92093; and Department of Human Genetics (S.W.D.), University of Michigan, Ann Arbor, Michigan 48109
| | - Rachel Larder
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine (H.X., H.M.H., J.D.M., S.L.M., C.T., S.S.L., C.M., R.L., P.L.M.), University of California, San Diego, La Jolla, California 92093; and Department of Human Genetics (S.W.D.), University of Michigan, Ann Arbor, Michigan 48109
| | - Pamela L Mellon
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine (H.X., H.M.H., J.D.M., S.L.M., C.T., S.S.L., C.M., R.L., P.L.M.), University of California, San Diego, La Jolla, California 92093; and Department of Human Genetics (S.W.D.), University of Michigan, Ann Arbor, Michigan 48109
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Bagchi D, Andrade J, Shupnik MA. A new role for wilms tumor protein 1: differential activities of + KTS and -KTS variants to regulate LHβ transcription. PLoS One 2015; 10:e0116825. [PMID: 25617744 PMCID: PMC4305298 DOI: 10.1371/journal.pone.0116825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 12/15/2014] [Indexed: 01/08/2023] Open
Abstract
Luteinizing hormone (LH) is synthesized and secreted throughout the reproductive cycle from gonadotrope cells in the anterior pituitary, and is required for steroidogenesis and ovulation. LH contains an α-subunit common with FSH, and a unique LHβ subunit that defines biological activity. Basal LHβ transcription is low and stimulated by hypothalamic GnRH, which induces synthesis of early growth response protein-1 (Egr1), and stimulates binding of transcription factors Egr1 and steroidogenic factor-1 (SF1) on the promoter. WT1 (Wilms tumor protein1) is a zinc finger transcription factor with an essential role in urogenital system development, and which regulates several reproductive genes via interactions with SF1 or binding to GC-rich elements such as Egr1 binding sites. We investigated a potential role for WT1 in LHβ transcription in clonal mouse gonadotrope LβT2 cells. WT1 was present in LβT2 and mouse pituitary cells, and protein bound to the endogenous LHβ promoter. Interestingly, mRNAs for WT1(+KTS), which contains a three amino-acid insertion between the 3rd and 4th zinc fingers, and the WT1 (-KTS) variant were both expressed at significant levels. WT1 mRNAs and protein were decreased approximately 50% by GnRH treatment, under conditions where Egr1 mRNA and protein, and LHβ transcription, were stimulated. Decreasing expression of mRNA for WT1 (-KTS) decreased stimulation of LHβ and Egr1 by GnRH, whereas decreasing both WT1 (-KTS) and (+KTS) increased endogenous LHβ transcription, and prevented LHβ but not Egr1 stimulation by GnRH, suggesting differing biological activities for the WT1 isoforms. Overexpression of WT1 showed that WT1(-KTS) enhanced LHβ promoter GnRH stimulation 2-to-3-fold and required the 3'Egr1 site, but WT1(+KTS) repressed both basal and GnRH-stimulated LHβ promoter activity by approximately 70%. Our data suggest that WT1 can modulate LHβ transcription, with differential roles for the two WT1 variants; WT1 (-KTS) enhances and WT1 (+KTS) suppresses transcription.
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Affiliation(s)
- Debalina Bagchi
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Josefa Andrade
- Department of Medicine, Division of Endocrinology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Margaret A. Shupnik
- Department of Medicine, Division of Endocrinology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
- * E-mail:
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Zheng W, Grafer CM, Kim J, Halvorson LM. Gonadotropin-Releasing Hormone and Gonadal Steroids Regulate Transcription Factor mRNA Expression in Primary Pituitary and Immortalized Gonadotrope Cells. Reprod Sci 2015; 22:285-99. [DOI: 10.1177/1933719114565031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Weiming Zheng
- Core Laboratories, St. Paul University Hospital, Dallas, TX, USA
| | - Constance M. Grafer
- Department of Obstetrics and Gynecology, Green Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Jin JM, Yang WX. Molecular regulation of hypothalamus-pituitary-gonads axis in males. Gene 2014; 551:15-25. [PMID: 25168889 DOI: 10.1016/j.gene.2014.08.048] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 07/24/2014] [Accepted: 08/24/2014] [Indexed: 10/24/2022]
Abstract
The hypothalamic-pituitary-gonadal axis (HPG) plays vital roles in reproduction and steroid hormone production in both sexes. The focus of this review is upon gene structures, receptor structures and the signaling pathways of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The hormones' functions in reproduction as well as consequences resulting from mutations are also summarized. Specific characteristics of hormones such as the pulsatile secretions of GnRH are also covered. The different regulators of the HPG axis are introduced including kisspeptin, activin, inhibin, follistatin, androgens and estrogen. This review includes not only their basic information, but also their unique function in the HPG axis. Here we view the HPG axis as a whole, so relations between ligands and receptors are well described crossing different levels of the HPG axis. Hormone interactions and transformations are also considered. The major information of this article is depicted in three figures summarizing the current discoveries on the HPG axis. This article systematically introduces the basic knowledge of the HPG axis and provides information of the current advances relating to reproductive hormones.
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Affiliation(s)
- Jia-Min Jin
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
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25
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Role of Orphan Nuclear Receptor DAX-1/NR0B1 in Development, Physiology, and Disease. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/582749] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
DAX-1/NR0B1 is an unusual orphan receptor that has a pivotal role in the development and function of steroidogenic tissues and of the reproductive axis. Recent studies have also indicated that this transcription factor has an important function in stem cell biology and in several types of cancer. Here I critically review the most important findings on the role of DAX-1 in development, physiology, and disease of endocrine tissues since the cloning of its gene twenty years ago.
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Thompson IR, Kaiser UB. GnRH pulse frequency-dependent differential regulation of LH and FSH gene expression. Mol Cell Endocrinol 2014; 385:28-35. [PMID: 24056171 PMCID: PMC3947649 DOI: 10.1016/j.mce.2013.09.012] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/10/2013] [Accepted: 09/10/2013] [Indexed: 12/14/2022]
Abstract
The pituitary gonadotropin hormones, FSH and LH, are essential for fertility. Containing an identical α-subunit (CGA), they are comprised of unique β-subunits, FSHβ and LHβ, respectively. These two hormones are regulated by the hypothalamic decapeptide, GnRH, which is released in a pulsatile manner from GnRH neurons located in the hypothalamus. Varying frequencies of pulsatile GnRH stimulate distinct signaling pathways and transcriptional machinery after binding to the receptor, GnRHR, on the cell surface of anterior pituitary gonadotropes. This ligand-receptor binding and activation orchestrates the synthesis and release of FSH and LH, in synergy with other effectors of gonadotropin production, such as activin, inhibin and steroids. Current research efforts aim to discover the mechanisms responsible for the decoding of the GnRH pulse signal by the gonadotrope. Modulating the response to GnRH has the potential to lead to new therapies for patients with altered gonadotropin secretion, such as those with hypothalamic amenorrhea or polycystic ovarian syndrome.
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Affiliation(s)
- Iain R Thompson
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, United States
| | - Ursula B Kaiser
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, United States.
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27
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Wang CM, Liu R, Wang L, Yang WH. Acidic residue Glu199 increases SUMOylation level of nuclear hormone receptor NR5A1. Int J Mol Sci 2013; 14:22331-45. [PMID: 24232453 PMCID: PMC3856066 DOI: 10.3390/ijms141122331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 11/01/2013] [Accepted: 11/05/2013] [Indexed: 01/29/2023] Open
Abstract
Steroidogenic factor 1 (NR5A1/SF1) is a well-known master regulator in controlling adrenal and sexual development, as well as regulating numerous genes involved in adrenal and gonadal steroidogenesis. Several studies including ours have demonstrated that NR5A1 can be SUMOylated on lysine 194 (K194, the major site) and lysine 119 (K119, the minor site), and the cycle of SUMOylation regulates NR5A1’s transcriptional activity. An extended consensus negatively charged amino acid-dependent SUMOylation motif (NDSM) enhances the specificity of substrate modification by SUMO has been reported; however, the mechanism of NDSM for NR5A1 remains to be clarified. In this study, we investigated the functional significance of the acidic residue located downstream from the core consensus SUMO site of NR5A1. Here we report that E199A (glutamic acid was replaced with alanine) of NR5A1 reduced, but not completely abolished, its SUMOylation level. We next characterized the functional role of NR5A1 E199A on target gene expression and protein levels. We found that E199A alone, as well as combination with K194R, increased Mc2r and Cyp19a1 reporter activities. Moreover, E199A alone as well as combination with K194R enhanced NR5A1-mediated STAR protein levels in mouse adrenocortical cancer Y1 cells. We also observed that E199A increased interaction of NR5A1 with CDK7 and SRC1. Overall, we provide the evidence that the acidic residue (E199) located downstream from the core consensus SUMO site of NR5A1 is, at least in part, required for SUMOylation of NR5A1 and for its mediated target gene and protein expression.
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Affiliation(s)
- Chiung-Min Wang
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA 31404, USA; E-Mail:
| | - Runhua Liu
- Department of Genetics and Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA; E-Mails: (R.L.); (L.W.)
| | - Lizhong Wang
- Department of Genetics and Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA; E-Mails: (R.L.); (L.W.)
| | - Wei-Hsiung Yang
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA 31404, USA; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-912-350-1708; Fax: +1-912-350-1765
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Andrade J, Quinn J, Becker RZ, Shupnik MA. AMP-activated protein kinase is a key intermediary in GnRH-stimulated LHβ gene transcription. Mol Endocrinol 2013; 27:828-39. [PMID: 23518923 DOI: 10.1210/me.2012-1323] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
GnRH regulation of pituitary gonadotropin gene transcription is critical for fertility, and metabolic dysregulation is associated with reproductive disorders and altered hypothalamic-pituitary responses. Here, we examined signaling pathways in gonadotropes through which GnRH modulates gonadotropin levels, and potential common signaling pathways with insulin. Using LβT2 cells, we show that GnRH rapidly (5 minutes) triggers activating phosphorylation of AMP-activated protein kinase (AMPK) up to 5-fold; this stimulation is enhanced by insulin through increased total AMPKα levels and activity. GnRH also stimulated c-Jun N-terminal kinase (JNK) and ERK activation, whereas insulin alone stimulated Akt. Inhibition of AMPK activity by compound C, or diminishing AMPK levels by small interfering RNA against AMPKα, prevented GnRH-stimulated transcription of the endogenous LHβ gene and transfected LHβ promoter. Egr-1 (early growth response-1), a transcription factor required for LHβ expression, is synthesized in response to GnRH, and compound C prevents this induction. However, overexpression of Egr-1 in the presence of compound C did not restore GnRH stimulation of LHβ, suggesting that AMPK stimulation of transcription also occurs through additional mechanisms or signaling pathways. One such pathway may be JNK activation, because GnRH stimulation of JNK activity and LHβ transcription occurs more slowly than stimulation of AMPK activity, and AMPK inhibition by compound C or small interfering RNA also prevented GnRH-stimulated JNK phosphorylation. Finally, in primary mouse pituitary cells, GnRH also stimulates AMPK, and AMPK inhibition suppresses GnRH-stimulated LHβ transcription. These studies indicate a novel role for AMPK in GnRH-stimulated transcription in pituitary gonadotropes and a potential common mechanism for GnRH and metabolic modulation of fertility.
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Affiliation(s)
- Josefa Andrade
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Virginia, Charlottesville, VA 22903, USA
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Fortin J, Kumar V, Zhou X, Wang Y, Auwerx J, Schoonjans K, Boehm U, Boerboom D, Bernard DJ. NR5A2 regulates Lhb and Fshb transcription in gonadotrope-like cells in vitro, but is dispensable for gonadotropin synthesis and fertility in vivo. PLoS One 2013; 8:e59058. [PMID: 23536856 PMCID: PMC3594184 DOI: 10.1371/journal.pone.0059058] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 02/11/2013] [Indexed: 11/18/2022] Open
Abstract
Successful mammalian reproduction depends on proper synthesis of the pituitary-derived glycoprotein hormones, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Several transcription factors cooperate to activate cell-specific and hormone-regulated expression of the gonadotropin beta subunits (Lhb and Fshb). Among these, NR5A1 (steroidogenic factor 1; SF1) has been shown to directly bind to the Lhb promoter, mediate basal and gonadotropin-releasing hormone (GnRH)-stimulated Lhb transcription, and possibly directly regulate Fshb expression. Recently, the closely-related NR5A2 was shown to activate the rat Lhb promoter in vitro. Here, we further characterized the role of NR5A2 in regulating gonadotropin synthesis. Ectopically expressed NR5A2 directly activated the murine Lhb promoter in a manner identical to that of NR5A1, whereas neither factor activated the murine Fshb promoter. In LβT2 gonadotrope-like cells, depletion of endogenous NR5A1 or NR5A2 impaired basal and GnRH-stimulated Lhb and Fshb transcription. To analyze the physiological role of NR5A2 in gonadotropes in vivo, we generated mice with a gonadotrope-specific deletion of Nr5a2. In contrast with our in vitro data, these mice had normal pituitary Lhb and Fshb expression and intact fertility. Together, our data establish that NR5A2 can act in a non-redundant manner to regulate Lhb and Fshb transcription in vitro, but is dispensable in vivo.
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Affiliation(s)
- Jérôme Fortin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Vikas Kumar
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
- Département de Biomédecine Vétérinaire, Université de Montréal, Ste-Hyacinthe, Québec, Canada
| | - Xiang Zhou
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Ying Wang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Johan Auwerx
- Laboratory of Integrative and Systems Physiology, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Suisse
| | - Kristina Schoonjans
- Laboratory of Integrative and Systems Physiology, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Suisse
| | - Ulrich Boehm
- Department of Pharmacology and Toxicology, University of Saarland School of Medicine, Homburg, Saarland, Germany
| | - Derek Boerboom
- Département de Biomédecine Vétérinaire, Université de Montréal, Ste-Hyacinthe, Québec, Canada
| | - Daniel J. Bernard
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
- * E-mail:
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30
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Thompson IR, Ciccone NA, Xu S, Zaytseva S, Carroll RS, Kaiser UB. GnRH pulse frequency-dependent stimulation of FSHβ transcription is mediated via activation of PKA and CREB. Mol Endocrinol 2013; 27:606-18. [PMID: 23393127 DOI: 10.1210/me.2012-1281] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Expression of pituitary FSH and LH, under the control of pulsatile GnRH, is essential for fertility. cAMP response element-binding protein (CREB) has been implicated in the regulation of FSHβ gene expression, but the molecular mechanisms by which pulsatile GnRH regulates CREB activation remain poorly understood. We hypothesized that CREB is activated by a distinct signaling pathway in response to pulsatile GnRH in a frequency-dependent manner to dictate the FSHβ transcriptional response. GnRH stimulation of CREB phosphorylation (pCREB) in the gonadotrope-derived LβT2 cell line was attenuated by a protein kinase A (PKA) inhibitor, H89. A dominant negative PKA (DNPKA) reduced GnRH-stimulated pCREB and markedly decreased GnRH stimulation of FSHβ mRNA and FSHβLUC activity, but had little effect on LHβLUC activity, indicating relative specificity of this pathway. In perifusion studies, FSHβ mRNA levels and FSHβLUC activities were increased by pulsatile GnRH, with significantly greater increases at low compared with high pulse frequencies. DNPKA markedly reduced these GnRH-stimulated FSHβ responses at both low and high pulse frequencies. Correlating with FSHβ activation, both PKA activity and levels of pCREB were increased to a greater extent by low compared with high GnRH pulse frequencies, and the induction of pCREB was also attenuated by overexpression of DNPKA at both low and high pulse frequencies. Taken together, these data indicate that a PKA-mediated signaling pathway mediates GnRH activation of CREB at low-pulse frequencies, playing a significant role in the decoding of the hypothalamic GnRH signal to result in frequency-dependent FSHβ activation.
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Affiliation(s)
- Iain R Thompson
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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31
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Arriola DJ, Mayo SL, Skarra DV, Benson CA, Thackray VG. FOXO1 transcription factor inhibits luteinizing hormone β gene expression in pituitary gonadotrope cells. J Biol Chem 2012; 287:33424-35. [PMID: 22865884 DOI: 10.1074/jbc.m112.362103] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Synthesis of luteinizing hormone (LH) is tightly controlled by a complex network of hormonal signaling pathways that can be modulated by metabolic cues, such as insulin. One group of candidate genes that may be regulated by insulin signaling in pituitary gonadotrope cells is the FOXO subfamily of forkhead transcription factors. In this study we investigated whether FOXO1 is expressed in gonadotropes and if it can modulate LH β-subunit (Lhb) gene expression. We demonstrated that FOXO1 is expressed in murine gonadotrope cells and that insulin signaling increased FOXO1 phosphorylation and cytoplasmic localization in a PI3K-dependent manner. We also showed that FOXO1 repressed basal transcription and gonadotropin-releasing hormone (GnRH) induction of both the murine and human LHB genes in LβT2 cells, suggesting that FOXO1 regulation of LHB transcription may be conserved between rodents and humans. Although we did not detect FOXO1 binding to the proximal Lhb promoter, the FOXO1 DNA binding domain was necessary for the suppression, suggesting that FOXO1 exerts its effect through protein-protein interactions with transcription factors/cofactors required for Lhb gene expression. FOXO1 repression mapped to the proximal Lhb promoter containing steroidogenic factor 1 (SF1), pituitary homeobox 1 (PTX1), and early growth response protein 1 (EGR1) binding elements. Additionally, FOXO1 blocked induction of the Lhb promoter with overexpressed SF1, PTX1, and EGR1, indicating that FOXO1 repression occurs via these transcription factors but not through regulation of their promoters. In summary, we demonstrate that FOXO1 phosphorylation and cellular localization is regulated by insulin signaling in gonadotropes and that FOXO1 inhibits Lhb transcription. Our study also suggests that FOXO1 may play an important role in controlling LH levels in response to metabolic cues.
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Affiliation(s)
- David J Arriola
- Department of Reproductive Medicine and the Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, California 92093, USA
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Breen KM, Thackray VG, Hsu T, Mak-McCully RA, Coss D, Mellon PL. Stress levels of glucocorticoids inhibit LHβ-subunit gene expression in gonadotrope cells. Mol Endocrinol 2012; 26:1716-31. [PMID: 22851703 DOI: 10.1210/me.2011-1327] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Increased glucocorticoid secretion is a common response to stress and has been implicated as a mediator of reproductive suppression upon the pituitary gland. We utilized complementary in vitro and in vivo approaches in the mouse to investigate the role of glucocorticoids as a stress-induced intermediate capable of gonadotrope suppression. Repeated daily restraint stress lengthened the ovulatory cycle of female mice and acutely reduced GnRH-induced LH secretion and synthesis of LH β-subunit (LHβ) mRNA, coincident with increased circulating glucocorticoids. Administration of a stress level of glucocorticoid, in the absence of stress, blunted LH secretion in ovariectomized female mice, demonstrating direct impairment of reproductive function by glucocorticoids. Supporting a pituitary action, glucocorticoid receptor (GR) is expressed in mouse gonadotropes and treatment with glucocorticoids reduces GnRH-induced LHβ expression in immortalized mouse gonadotrope cells. Analyses revealed that glucocorticoid repression localizes to a region of the LHβ proximal promoter, which contains early growth response factor 1 (Egr1) and steroidogenic factor 1 sites critical for GnRH induction. GR is recruited to this promoter region in the presence of GnRH, but not by dexamethasone alone, confirming the necessity of the GnRH response for GR repression. In lieu of GnRH, Egr1 induction is sufficient for glucocorticoid repression of LHβ expression, which occurs via GR acting in a DNA- and dimerization-independent manner. Collectively, these results expose the gonadotrope as an important neuroendocrine site impaired during stress, by revealing a molecular mechanism involving Egr1 as a critical integrator of complex formation on the LHβ promoter during GnRH induction and GR repression.
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Affiliation(s)
- Kellie M Breen
- Department of Reproductive Medicine/Neuroscience, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0674, USA
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Yuen T, Choi SG, Pincas H, Waring DW, Sealfon SC, Turgeon JL. Optimized amplification and single-cell analysis identify GnRH-mediated activation of Rap1b in primary rat gonadotropes. Mol Cell Endocrinol 2012; 350:10-9. [PMID: 22127306 PMCID: PMC3919063 DOI: 10.1016/j.mce.2011.11.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 11/15/2011] [Accepted: 11/15/2011] [Indexed: 10/15/2022]
Abstract
Identifying the early gene program induced by GnRH would help understand how GnRH-activated signaling pathways modulate gonadotrope secretory response. We previously analyzed GnRH-induced early genes in LβT2 cells, however these lack GnRH self-potentiation, a physiological attribute of gonadotropes. To minimize cellular heterogeneity, rat primary pituitary cultures were enriched for gonadotropes by 40-60% using a sedimentation gradient. Given the limited number of gonadotropes, RNA was amplified prior to microarray analysis. Thirty-three genes were up-regulated 40 min after GnRH stimulation. Real-time PCR confirmed regulation of several transcripts including fosB, c-fos, egr-2 and rap1b, a small GTPase and member of the Ras family. GnRH stimulated rap1b gene expression in gonadotropes, measured by a sensitive single cell assay. Immunocytochemistry revealed increased Rap1 protein in GnRH-stimulated gonadotropes. These data establish rap1b as a novel gene rapidly induced by GnRH and a candidate to modulate gonadotropin secretion in rat gonadotropes.
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Affiliation(s)
- Tony Yuen
- Center for Translational Systems Biology and Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029, United States
| | - Soon Gang Choi
- Center for Translational Systems Biology and Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029, United States
| | - Hanna Pincas
- Center for Translational Systems Biology and Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029, United States
| | - Dennis W. Waring
- Division of Endocrinology, Department of Internal Medicine, School of Medicine, University of California, Davis, CA 95616, United States
| | - Stuart C. Sealfon
- Center for Translational Systems Biology and Department of Neurology, Mount Sinai School of Medicine, New York, NY 10029, United States
| | - Judith L. Turgeon
- Division of Endocrinology, Department of Internal Medicine, School of Medicine, University of California, Davis, CA 95616, United States
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Harris DT, Horvitz HR. MAB-10/NAB acts with LIN-29/EGR to regulate terminal differentiation and the transition from larva to adult in C. elegans. Development 2011; 138:4051-62. [PMID: 21862562 DOI: 10.1242/dev.065417] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Caenorhabditis elegans, a well-defined pathway of heterochronic genes ensures the proper timing of stage-specific developmental events. During the final larval stage, an upregulation of the let-7 microRNA indirectly activates the terminal differentiation factor and central regulator of the larval-to-adult transition, LIN-29, via the downregulation of the let-7 target genes lin-41 and hbl-1. Here, we identify a new heterochronic gene, mab-10, and show that mab-10 encodes a NAB (NGFI-A-binding protein) transcriptional co-factor. MAB-10 acts with LIN-29 to control the expression of genes required to regulate a subset of differentiation events during the larval-to-adult transition, and we show that the NAB-interaction domain of LIN-29 is conserved in Kruppel-family EGR (early growth response) proteins. In mammals, EGR proteins control the differentiation of multiple cell lineages, and EGR-1 acts with NAB proteins to initiate menarche by regulating the transcription of the luteinizing hormone β subunit. Genome-wide association studies of humans and various studies of mouse recently have implicated the mammalian homologs of the C. elegans heterochronic gene lin-28 in regulating cellular differentiation and the timing of menarche. Our work suggests that human homologs of multiple C. elegans heterochronic genes might act in an evolutionarily conserved pathway to promote cellular differentiation and the onset of puberty.
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Affiliation(s)
- David T Harris
- Howard Hughes Medical Institute, Department of Biology, 68-425, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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Jadhav U, Harris RM, Jameson JL. Hypogonadotropic hypogonadism in subjects with DAX1 mutations. Mol Cell Endocrinol 2011; 346:65-73. [PMID: 21672607 PMCID: PMC3185185 DOI: 10.1016/j.mce.2011.04.017] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 04/07/2011] [Indexed: 11/17/2022]
Abstract
DAX1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1; also known as NROB1, nuclear receptor subfamily 0, group B, member 1) encodes a nuclear receptor that is expressed in embryonic stem (ES) cells, steroidogenic tissues (gonads, adrenals), the ventromedial hypothalamus (VMH), and pituitary gonadotropes. Humans with DAX1 mutations develop an X-linked syndrome referred to as adrenal hypoplasia congenita (AHC). These boys typically present in infancy with adrenal failure but later fail to undergo puberty because of hypogonadotropic hypogonadism (HHG). The adrenal failure reflects a developmental abnormality in the transition of the fetal to adult zone, resulting in glucocorticoid and mineralocorticoid deficiency. The etiology of HHG involves a combined and variable deficiency of hypothalamic GnRH secretion and/or pituitary responsiveness to GnRH resulting in low LH, FSH and testosterone. Treatment with exogenous gonadotropins generally does not induce spermatogenesis. Animal models indicate that DAX1 also plays a critical role in testis development and function. As a nuclear receptor, DAX1 has been shown to function as a transcriptional repressor, particularly of pathways regulated by other nuclear receptors, such as steroidogenic factor 1 (SF1). In addition to reproductive tissues, DAX1 is also expressed at high levels in ES cells and plays a role in the maintenance of pluripotentiality. Here we review the clinical manifestations associated with DAX1 mutations as well as the evolving information about its function based on animal models and in vitro studies.
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Affiliation(s)
| | | | - J. Larry Jameson
- Division of Endocrinology, Department of Medicine, Northwestern University Feinberg School of Medicine, 303 E. Superior Street, Chicago, IL 60611
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Mortensen AH, MacDonald JW, Ghosh D, Camper SA. Candidate genes for panhypopituitarism identified by gene expression profiling. Physiol Genomics 2011; 43:1105-16. [PMID: 21828248 DOI: 10.1152/physiolgenomics.00080.2011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Mutations in the transcription factors PROP1 and PIT1 (POU1F1) lead to pituitary hormone deficiency and hypopituitarism in mice and humans. The dysmorphology of developing Prop1 mutant pituitaries readily distinguishes them from those of Pit1 mutants and normal mice. This and other features suggest that Prop1 controls the expression of genes besides Pit1 that are important for pituitary cell migration, survival, and differentiation. To identify genes involved in these processes we used microarray analysis of gene expression to compare pituitary RNA from newborn Prop1 and Pit1 mutants and wild-type littermates. Significant differences in gene expression were noted between each mutant and their normal littermates, as well as between Prop1 and Pit1 mutants. Otx2, a gene critical for normal eye and pituitary development in humans and mice, exhibited elevated expression specifically in Prop1 mutant pituitaries. We report the spatial and temporal regulation of Otx2 in normal mice and Prop1 mutants, and the results suggest Otx2 could influence pituitary development by affecting signaling from the ventral diencephalon and regulation of gene expression in Rathke's pouch. The discovery that Otx2 expression is affected by Prop1 deficiency provides support for our hypothesis that identifying molecular differences in mutants will contribute to understanding the molecular mechanisms that control pituitary organogenesis and lead to human pituitary disease.
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Affiliation(s)
- Amanda H Mortensen
- Department of Human Genetics, Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109-5618, USA
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Lo A, Zheng W, Gong Y, Crochet JR, Halvorson LM. GATA transcription factors regulate LHβ gene expression. J Mol Endocrinol 2011; 47:45-58. [PMID: 21571865 DOI: 10.1530/jme-10-0137] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The GATA family of transcription factors are critical determinants of cell differentiation as well as regulation of adult gene expression throughout the reproductive axis. Within the anterior pituitary gland, GATA factors have been shown to increase glycoprotein α-subunit gene promoter activity; however, nothing has been known about the impact of these factors on expression of the gonadotropin β-subunits. In this study, we demonstrate expression of both GATA2 and GATA4 in primary mouse gonadotropes and the gonadotrope cell line, LβT2. Based on the transient transfection in fibroblast cells, GATA factors increase LH β-subunit gene (LHβ) promoter activity alone and in synergy with the orphan nuclear receptors steroidogenic factor-1 (SF-1) and liver receptor homologue-1 (LRH-1). The GATA response was localized to a DNA regulatory region at position -101 in the rat LHβ gene promoter which overlaps with a previously described cis-element for pituitary homeobox-1 (Pitx1) and is flanked by two SF-1/LRH-1 regulatory sites. As determined by gel shift, GATA and Pitx1 can compete for binding to this element. Furthermore, mutation analysis revealed a requirement for both the GATA/Pitx1 and the SF-1/LRH-1 cis-elements in order to achieve synergy. These studies identify a novel role for GATA transcription factors in the pituitary and reveal additional molecular mechanisms by which precise modulation of LHβ gene expression can be achieved.
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Affiliation(s)
- Ann Lo
- Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9032, USA
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Mistry DS, Tsutsumi R, Fernandez M, Sharma S, Cardenas SA, Lawson MA, Webster NJG. Gonadotropin-releasing hormone pulse sensitivity of follicle-stimulating hormone-beta gene is mediated by differential expression of positive regulatory activator protein 1 factors and corepressors SKIL and TGIF1. Mol Endocrinol 2011; 25:1387-403. [PMID: 21659477 DOI: 10.1210/me.2011-0032] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Gonadotropin synthesis and release is dependent on pulsatile stimulation by the hypothalamic neuropeptide GnRH. Generally, slow GnRH pulses promote FSH production, whereas rapid pulses favor LH, but the molecular mechanism underlying this pulse sensitivity is poorly understood. In this study, we developed and tested a model for FSHβ regulation in mouse LβT2 gonadotropes. By mining a previous microarray data set, we found that mRNA for positive regulators of Fshb expression, such as Fos and Jun, were up-regulated at slower pulse frequencies than a number of potential negative regulators, such as the corepressors Skil, Crem, and Tgif1. These latter corepressors reduced Fshb promoter activity whether driven by transfection of individual transcription factors or by treatment with GnRH and activin. Overexpression of binding or phosphorylation-defective ski-oncogene-like protein (SKIL) and TG interacting factor (TGIF1) mutants, however, failed to repress Fshb promoter activity. Knockdown of the endogenous repressors SKIL and TGIF1, but not cAMP response element-modulator, increased Fshb promoter activity driven by constant GnRH or activin. Chromatin immunoprecipitation analysis showed that FOS, SKIL, and TGIF1 occupy the FSHβ promoter in a cyclical manner after GnRH stimulation. Overexpression of corepressors SKIL or TGIF1 repressed induction of the Fshb promoter at the slow GnRH pulse frequency but had little effect at the fast pulse frequency. In contrast, knockdown of endogenous SKIL or TGIF1 selectively increased Fshb mRNA at the fast GnRH pulse frequency. Therefore, we propose a potential mechanism by which production of gonadotropin Fshb is modulated by positive transcription factors and negative corepressors with different pulse sensitivities.
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Affiliation(s)
- Devendra S Mistry
- Medical Research Service, Veterans Affairs San Diego Healthcare System, San Diego, California 92161, USA
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Burger LL, Haisenleder DJ, Marshall JC. GnRH pulse frequency differentially regulates steroidogenic factor 1 (SF1), dosage-sensitive sex reversal-AHC critical region on the X chromosome gene 1 (DAX1), and serum response factor (SRF): potential mechanism for GnRH pulse frequency regulation of LH beta transcription in the rat. Endocrine 2011; 39:212-9. [PMID: 21409515 DOI: 10.1007/s12020-011-9440-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 01/30/2011] [Indexed: 10/18/2022]
Abstract
The issue of how rapid frequency GnRH pulses selectively stimulate LH transcription is not fully understood. The rat LHβ promoter contains two GnRH-responsive regions: the proximal region has binding elements for SF1, and the distal site contains a CArG box, which binds SRF. This study determined whether GnRH stimulates pituitary SF1, DAX1 (an endogenous SF1 inhibitor), and SRF transcription in vivo, and whether regulation is frequency dependent. Male rats were pulsed with 25 ng GnRH i.v. every 30 min or every 240 min for 1-24 h, and primary transcripts (PTs) and mRNAs were measured by real time PCR. Fast frequency GnRH pulses (every 30 min) increased SF1 PT (threefold) within 1 h, and then declined after 6 h. SF1 mRNA also increased within 1 h and remained elevated through 24 h. Fast frequency GnRH also stimulated a transient increase in DAX1 PT (twofold after 1 h) and mRNA (1.7-fold after 6 h), while SRF mRNA rose briefly at 1 h. Slow frequency pulses did not affect gene expression of SF1, DAX1, or SRF. These findings support a mechanistic link between SF1 in the frequency regulation of LHβ transcription by pulsatile GnRH.
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Affiliation(s)
- Laura L Burger
- University of Michigan, Medical Sciences Building II, Ann Arbor, MI 48109, USA.
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Vasauskas AA, Hubler TR, Mahanic C, Gibson S, Kahn AG, Scammell JG. Regulation and distribution of squirrel monkey chorionic gonadotropin and secretogranin II in the pituitary. Gen Comp Endocrinol 2011; 170:509-13. [PMID: 21095191 PMCID: PMC3022110 DOI: 10.1016/j.ygcen.2010.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 10/26/2010] [Accepted: 11/12/2010] [Indexed: 01/13/2023]
Abstract
Secretogranin II (SgII) is a member of the granin family of proteins found in neuroendocrine and endocrine cells. The expression and storage of SgII in the pituitary gland of Old World primates and rodents have been linked with those of luteinizing hormone (LH). However, New World primates including squirrel monkeys do not express LH in the pituitary gland, but rather CG is expressed. If CG takes on the luteotropic role of LH in New World primates, SgII may be associated with the expression and storage of CG in the pituitary gland. The goal of this study was to evaluate the regulation and distribution of CG and SgII in the squirrel monkey. A DNA fragment containing approximately 750 bp of squirrel monkey SgII promoter was isolated from genomic DNA and found to contain a cyclic-AMP response element that is also present in the human SgII promoter and important for GnRH responsiveness. The squirrel monkey and human SgII promoters were similarly activated by GnRH in luciferase reporter gene assays in LβT2 cells. Double immunofluorescence microscopy demonstrated close association of SgII and CG in gonadotrophs of squirrel monkey pituitary gland. These results suggest that CG and SgII have a similar intercellular distribution and are coregulated in squirrel monkey pituitary gland.
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Affiliation(s)
- Audrey A. Vasauskas
- Department of Comparative Medicine, University of South Alabama College of Medicine, Mobile, Alabama 36688
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, Alabama 36688
| | - Tina R. Hubler
- Department of Biology, University of North Alabama, Florence, Alabama 35632
| | - Christina Mahanic
- Department of Comparative Medicine, University of South Alabama College of Medicine, Mobile, Alabama 36688
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, Alabama 36688
| | - Susan Gibson
- Department of Comparative Medicine, University of South Alabama College of Medicine, Mobile, Alabama 36688
| | - Andrea G. Kahn
- Department of Pathology, University of South Alabama Medical Center, Mobile, Alabama 36617
| | - Jonathan G. Scammell
- Department of Comparative Medicine, University of South Alabama College of Medicine, Mobile, Alabama 36688
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, Alabama 36688
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41
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Vasauskas AA, Hubler TR, Boston L, Scammell JG. Tissue-specific expression of squirrel monkey chorionic gonadotropin. Gen Comp Endocrinol 2011; 170:514-21. [PMID: 21130091 PMCID: PMC3022102 DOI: 10.1016/j.ygcen.2010.11.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 10/26/2010] [Accepted: 11/29/2010] [Indexed: 11/27/2022]
Abstract
Pituitary gonadotropins LH and FSH play central roles in reproductive function. In Old World primates, LH stimulates ovulation in females and testosterone production in males. Recent studies have found that squirrel monkeys and other New World primates lack expression of LH in the pituitary. Instead, chorionic gonadotropin (CG), which is normally only expressed in the placenta of Old World primates, is the active luteotropic pituitary hormone in these animals. The goal of this study was to investigate the tissue-specific regulation of squirrel monkey CG. We isolated the squirrel monkey CGβ gene and promoter from genomic DNA from squirrel monkey B-lymphoblasts and compared the promoter sequence to that of the common marmoset, another New World primate, and human and rhesus macaque CGβ and LHβ. Using reporter gene assays, we found that a squirrel monkey CGβ promoter fragment (-1898/+9) is active in both mouse pituitary LβT2 and human placenta JEG3 cells, but not in rat adrenal PC12 cells. Furthermore, within this construct separate cis-elements are responsible for pituitary- and placenta-specific expression. Pituitary-specific expression is governed by Egr-1 binding sites in the proximal 250 bp of the promoter, whereas placenta-specific expression is controlled by AP-2 sites further upstream. Thus, selective expression of the squirrel monkey CGβ promoter in pituitary and placental cells is governed by distinct cis-elements that exhibit homology with human LHβ and marmoset CGβ promoters, respectively.
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Affiliation(s)
- Audrey A. Vasauskas
- Department of Comparative Medicine, University of South Alabama College of Medicine, Mobile, Alabama 36688
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, Alabama 36688
| | - Tina R. Hubler
- Department of Biology, University of North Alabama, Florence, Alabama 35632
| | - Lori Boston
- Department of Biology, University of North Alabama, Florence, Alabama 35632
| | - Jonathan G. Scammell
- Department of Comparative Medicine, University of South Alabama College of Medicine, Mobile, Alabama 36688
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, Alabama 36688
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Zheng W, Horton CD, Kim J, Halvorson LM. The orphan nuclear receptors COUP-TFI and COUP-TFII regulate expression of the gonadotropin LHβ gene. Mol Cell Endocrinol 2010; 330:59-71. [PMID: 20797425 DOI: 10.1016/j.mce.2010.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 07/14/2010] [Accepted: 08/17/2010] [Indexed: 11/26/2022]
Abstract
Normal sexual development and reproductive function depend on precise temporal and quantitative expression of the pituitary gonadotropins, LH and FSH. LHβ-subunit gene expression is achieved by transcription factors acting at highly conserved and closely spaced cis-elements in the proximal 200 base pairs of the promoter. We now demonstrate that LHβ promoter activity is further regulated by the orphan nuclear receptors, chicken ovalbumin upstream promoter-transcription factors (COUP-TFI and COUP-TFII). These data establish that COUP-TFs are expressed in primary pituitary gonadotropes and two gonadotrope-derived cell lines. COUP-TFs bind to two promoter regions in the LHβ gene which overlap but are distinct from two previously defined cis-elements for another orphan nuclear receptor, steroidogenic factor-1 (SF-1). Transient transfection studies demonstrated that COUP-TFs stimulate LHβ gene promoter activity in the absence of SF-1, but blunt SF-1-mediated stimulation of gene expression in a reporter construct containing both SF-1 cis-elements (GSEs). Evaluation of constructs containing mutations or truncations in the GSEs revealed a complex pattern of activation and inhibition by COUP-TF on this promoter, suggesting multiple mechanisms by which this factor modulates LHβ gene expression. To our knowledge, these data are the first to demonstrate COUP-TF expression and function in pituitary gonadotropes.
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Affiliation(s)
- Weiming Zheng
- Division of Reproductive Endocrinology, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9032, USA
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Yang WH, Gutierrez NM, Wang L, Ellsworth BS, Wang CM. Synergistic activation of the Mc2r promoter by FOXL2 and NR5A1 in mice. Biol Reprod 2010; 83:842-51. [PMID: 20650879 DOI: 10.1095/biolreprod.110.085621] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Forkhead box protein L2 (FOXL2) is the earliest ovarian marker and plays an important role in the regulation of cholesterol and steroid metabolism, inflammation, apoptosis, and ovarian development and function. Mutations and deficiencies of the human FOXL2 gene have been shown to cause blepharophimosis-ptosis-epicanthus inversus syndrome as well as premature ovarian failure. Although Foxl2 interacts with steroidogenic factor 1 (Nr5a1) and up-regulates cyp19a1a gene transcription in fish, FOXL2 represses the transcriptional activity of the gene that codes for steroidogenic acute regulatory protein (Star) in mice. Most of the recent studies have heavily focused on the FOXL2 target genes (Star and Cyp19a1) in the ovaries. Hence, it is of importance to search for other downstream targets of FOXL2 and for the possibility of FOXL2 expression in nonovarian tissues. Herein, we demonstrate that the interplay between FOXL2 and NR5A1 regulates Star and melanocortin 2 receptor (Mc2r) gene expression in mammalian systems. Both FOXL2 and NR5A1 are expressed in ovarian and adrenal gland tissues. As expected, FOXL2 represses and NR5A1 enhances the promoter activity of Star. Notably, the promoter activity of Mc2r is activated by FOXL2 in a dose-dependent manner. Surprisingly, we found that FOXL2 and NR5A1 synergistically up-regulate the transcriptional activity of Mc2r. By mapping the Mc2r promoter, we provide evidence that distal NR5A1 response elements (-1410 and -975) are required for synergistic activation by FOXL2 and NR5A1. These results suggest that the interplay between FOXL2 and NR5A1 on the Mc2r promoter functions as a novel mechanism for regulating MC2R-mediated cell signaling as well as steroidogenesis in adrenal glands.
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Affiliation(s)
- Wei-Hsiung Yang
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia 31404-3089, USA.
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Bliss SP, Navratil AM, Xie J, Roberson MS. GnRH signaling, the gonadotrope and endocrine control of fertility. Front Neuroendocrinol 2010; 31:322-40. [PMID: 20451543 PMCID: PMC2923852 DOI: 10.1016/j.yfrne.2010.04.002] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2010] [Revised: 04/26/2010] [Accepted: 04/30/2010] [Indexed: 11/28/2022]
Abstract
Mammalian reproductive cycles are controlled by an intricate interplay between the hypothalamus, pituitary and gonads. Central to the function of this axis is the ability of the pituitary gonadotrope to appropriately respond to stimulation by gonadotropin-releasing hormone (GnRH). This review focuses on the role of cell signaling and in particular, mitogen-activated protein kinase (MAPK) activities regulated by GnRH that are necessary for normal fertility. Recently, new mouse models making use of conditional gene deletion have shed new light on the relationships between GnRH signaling and fertility in both male and female mice. Within the reproductive axis, GnRH signaling is initiated through discrete membrane compartments in which the receptor resides leading to the activation of the extracellular signal-regulated kinases (ERKs 1/2). As defined by gonadotrope-derived cellular models, the ERKs appear to play a central role in the regulation of a cohort of immediate early genes that regulate the expression of late genes that, in part, define the differentiated character of the gonadotrope. Recent data would suggest that in vivo, conditional, pituitary-specific disruption of ERK signaling by GnRH leads to a gender-specific perturbation of fertility. Double ERK knockout in the anterior pituitary leads to female infertility due to LH biosynthesis deficiency and a failure in ovulation. In contrast, male mice are modestly LH deficient; however, this does not have an appreciable impact on fertility.
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Affiliation(s)
- Stuart P Bliss
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, United States
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Bernard DJ, Fortin J, Wang Y, Lamba P. Mechanisms of FSH synthesis: what we know, what we don't, and why you should care. Fertil Steril 2010; 93:2465-85. [DOI: 10.1016/j.fertnstert.2010.03.034] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 03/11/2010] [Indexed: 12/17/2022]
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Luo Z, Wijeweera A, Oh Y, Liou YC, Melamed P. Pin1 facilitates the phosphorylation-dependent ubiquitination of SF-1 to regulate gonadotropin beta-subunit gene transcription. Mol Cell Biol 2010; 30:745-63. [PMID: 19995909 PMCID: PMC2812243 DOI: 10.1128/mcb.00807-09] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 09/10/2009] [Accepted: 11/23/2009] [Indexed: 11/20/2022] Open
Abstract
Pin1 is a peptidyl-prolyl cis-trans isomerase which catalyzes the isomerization of phosphorylated Ser/Thr-Pro peptide bonds. Pin1 knockout mice have marked abnormalities in their reproductive development and function. However, the molecular mechanisms underlying their reproductive defects are poorly understood. Herein, we demonstrate that Pin1 is required for both basal and GnRH-induced gonadotropin beta-subunit gene transcription, through interactions with the transcription factors SF-1, Pitx1, and Egr-1. Pin1 activates transcription of the gonadotropin beta-subunit genes synergistically with these transcription factors, either by modulating their stability or by increasing their protein-protein interactions. Notably, we provide evidence that Pin1 is required for the Ser203 phosphorylation-dependent ubiquitination of SF-1, which facilitates SF-1-Pitx1 interactions and therefore results in an enhancement of SF-1 transcriptional activity. Furthermore, we demonstrate that in gonadotrope cells, sufficient levels of activated Pin1 are maintained through transcriptional and posttranslational regulation by GnRH-induced signaling cascades. Our results suggest that Pin1 functions as a novel player in GnRH-induced signal pathways and is involved in gonadotropin beta-subunit gene transcription by modulating the activity of various specific transcription factors.
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Affiliation(s)
- Zhuojuan Luo
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore 117543, Singapore, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Andrea Wijeweera
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore 117543, Singapore, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Yingzi Oh
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore 117543, Singapore, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Yih-Cherng Liou
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore 117543, Singapore, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Philippa Melamed
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore 117543, Singapore, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, 32000, Israel
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Thackray VG, Mellon PL, Coss D. Hormones in synergy: regulation of the pituitary gonadotropin genes. Mol Cell Endocrinol 2010; 314:192-203. [PMID: 19747958 PMCID: PMC2815122 DOI: 10.1016/j.mce.2009.09.003] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 09/02/2009] [Accepted: 09/02/2009] [Indexed: 11/23/2022]
Abstract
The precise interplay of hormonal influences that governs gonadotropin hormone production by the pituitary includes endocrine, paracrine and autocrine actions of hypothalamic gonadotropin-releasing hormone (GnRH), activin and steroids. However, most studies of hormonal regulation of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the pituitary gonadotrope have been limited to analyses of the isolated actions of individual hormones. LHbeta and FSHbeta subunits have distinct patterns of expression during the menstrual/estrous cycle as a result of the integration of activin, GnRH, and steroid hormone action. In this review, we focus on studies that delineate the interplay among these hormones in the regulation of LHbeta and FSHbeta gene expression in gonadotrope cells and discuss how signaling cross-talk contributes to differential expression. We also discuss how recent technological advances will help identify additional factors involved in the differential hormonal regulation of LH and FSH.
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Affiliation(s)
| | | | - Djurdjica Coss
- To whom the correspondence should be addressed: Djurdjica Coss, Department of Reproductive Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0674, Phone: (858) 534-1762, Fax: (858) 534-1438,
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Burger LL, Haisenleder DJ, Aylor KW, Marshall JC. Regulation of Lhb and Egr1 gene expression by GNRH pulses in rat pituitaries is both c-Jun N-terminal kinase (JNK)- and extracellular signal-regulated kinase (ERK)-dependent. Biol Reprod 2009; 81:1206-15. [PMID: 19710510 PMCID: PMC2788048 DOI: 10.1095/biolreprod.109.079426] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Revised: 07/06/2009] [Accepted: 07/29/2009] [Indexed: 01/17/2023] Open
Abstract
Pulsatile GNRH regulates the gonadotropin subunit genes in a differential manner, with faster frequencies favoring Lhb gene expression and slower frequencies favoring Fshb. Early growth response 1 (EGR1) is critical for Lhb gene transcription. We examined GNRH regulation of EGR1 and its two corepressors, Ngfi-A-binding proteins 1 and 2 (NAB1 and NAB2), both in vivo and in cultured rat pituitary cells. In rats, fast GNRH pulses (every 30 min) stably induced Egr1 primary transcript (PT) and mRNA 2-fold (P < 0.05) for 1-24 h. In contrast, slow GNRH pulses (every 240 min) increased Egr1 PT at 24 h (6-fold; P < 0.05) but increased Egr1 mRNA 4- to 5-fold between 4 and 24 h. Both GNRH pulse frequencies increased EGR1 protein 3- to 4-fold. In cultured rat pituitary cells, GNRH pulses (every 60 min) increased Egr1 (PT, 2.5- to 3-fold; mRNA, 1.5- to 2-fold; P < 0.05). GNRH pulses had little effect on Nab1/2 PT/mRNAs either in vivo or in vitro. We also examined specific intracellular signaling cascades activated by GNRH. Inhibitors of mitogen-activated protein kinase 8/9 (MAPK8/9 [also known as JNK]; SP600125) and MAP Kinase Kinase 1 (MAP2K1 [also known as MEK1]; PD98059) either blunted or totally suppressed the GNRH induction of Lhb PT and Egr1 PT/mRNA, whereas the MAPK14 (also known as p38) inhibitor SB203580 did not. In summary, pulsatile GNRH stimulates Egr1 gene expression and protein in vivo but not in a frequency-dependent manner. Additionally, GNRH-induced Egr1 gene expression is mediated by MAPK8/9 and MAPK1/3, and both are critical for Lhb gene transcription.
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Affiliation(s)
- Laura L Burger
- Division of Endocrinology and Metabolism, Department of Medicine, and the Center for Research in Reproduction, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908, USA.
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Resuehr HES, Resuehr D, Olcese J. Induction of mPer1 expression by GnRH in pituitary gonadotrope cells involves EGR-1. Mol Cell Endocrinol 2009; 311:120-5. [PMID: 19616057 DOI: 10.1016/j.mce.2009.07.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 05/30/2009] [Accepted: 07/08/2009] [Indexed: 12/01/2022]
Abstract
We reported earlier that gonadotropin-releasing hormone (GnRH) activates period1 (mPer1) gene expression in immortalized gonadotropes through protein kinase C and p42/44 mitogen-activated protein kinase pathways. GnRH stimulation also leads to the upregulation of early growth response protein 1 (EGR-1), a critical transcription factor for GnRH-induced luteinizing hormone beta (LHbeta) synthesis. The parallels between the GnRH-LHbeta and the GnRH-mPer1 pathways led us to explore whether EGR-1 is involved in the regulation of mPer1 expression in gonadotropes. Of particular interest was the presence of an EGR-1 binding site in the proximal promoter of the mPer1 gene. Stimulation of LbetaT2 gonadotrope cells with a GnRH agonist caused the rapid induction of Egr-1 mRNA, which was rapidly followed by mPer1 expression. Chromatin immunoprecipitation revealed that the mPer1 promoter can bind EGR-1, while site-directed mutagenesis experiments confirmed the involvement of Egr-1 sequences in maintaining basal and allowing GnRH-stimulated mPer1 transcription. By means of RNA interference experiments, it could also be demonstrated that silencing of Egr-1 expression resulted in markedly lower mPer1 transcript levels. This silencing effect of the Egr-1 siRNA could be rescued by transfecting the cells with an EGR-1 overexpression vector. In summary, these results all point to a role for the EGR-1 protein in transactivating both the LHbeta as well as the mPer1 gene in pituitary gonadotrope cells.
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Affiliation(s)
- H E Sikes Resuehr
- Florida State University College of Medicine, Department of Biomedical Sciences, 1115 West Call Street, Tallahassee, FL 32306-4300, USA
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Bliss SP, Miller A, Navratil AM, Xie J, McDonough SP, Fisher PJ, Landreth GE, Roberson MS. ERK signaling in the pituitary is required for female but not male fertility. Mol Endocrinol 2009; 23:1092-101. [PMID: 19372235 DOI: 10.1210/me.2009-0030] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Males and females require different patterns of pituitary gonadotropin secretion for fertility. The mechanisms underlying these gender-specific profiles of pituitary hormone production are unknown; however, they are fundamental to understanding the sexually dimorphic control of reproductive function at the molecular level. Several studies suggest that ERK1 and -2 are essential modulators of hypothalamic GnRH-mediated regulation of pituitary gonadotropin production and fertility. To test this hypothesis, we generated mice with a pituitary-specific depletion of ERK1 and 2 and examined a range of physiological parameters including fertility. We find that ERK signaling is required in females for ovulation and fertility, whereas male reproductive function is unaffected by this signaling deficiency. The effects of ERK pathway ablation on LH biosynthesis underlie this gender-specific phenotype, and the molecular mechanism involves a requirement for ERK-dependent up-regulation of the transcription factor Egr1, which is necessary for LHbeta expression. Together, these findings represent a significant advance in elucidating the molecular basis of gender-specific regulation of the hypothalamic-pituitary-gonadal axis and sexually dimorphic control of fertility.
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Affiliation(s)
- Stuart P Bliss
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
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