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Wang HQ, Ma YR, Zhang YX, Wei FH, Zheng Y, Ji ZH, Guo HX, Wang T, Zhang JB, Yuan B. GnRH-driven FTO-mediated RNA m 6A modification promotes gonadotropin synthesis and secretion. BMC Biol 2024; 22:104. [PMID: 38702712 PMCID: PMC11069278 DOI: 10.1186/s12915-024-01905-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 04/26/2024] [Indexed: 05/06/2024] Open
Abstract
BACKGROUND Gonadotropin precisely controls mammalian reproductive activities. Systematic analysis of the mechanisms by which epigenetic modifications regulate the synthesis and secretion of gonadotropin can be useful for more precise regulation of the animal reproductive process. Previous studies have identified many differential m6A modifications in the GnRH-treated adenohypophysis. However, the molecular mechanism by which m6A modification regulates gonadotropin synthesis and secretion remains unclear. RESULTS Herein, it was found that GnRH can promote gonadotropin synthesis and secretion by promoting the expression of FTO. Highly expressed FTO binds to Foxp2 mRNA in the nucleus, exerting a demethylation function and reducing m6A modification. After Foxp2 mRNA exits the nucleus, the lack of m6A modification prevents YTHDF3 from binding to it, resulting in increased stability and upregulation of Foxp2 mRNA expression, which activates the cAMP/PKA signaling pathway to promote gonadotropin synthesis and secretion. CONCLUSIONS Overall, the study reveals the molecular mechanism of GnRH regulating the gonadotropin synthesis and secretion through FTO-mediated m6A modification. The results of this study allow systematic interpretation of the regulatory mechanism of gonadotropin synthesis and secretion in the pituitary at the epigenetic level and provide a theoretical basis for the application of reproductive hormones in the regulation of animal artificial reproduction.
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Affiliation(s)
- Hao-Qi Wang
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, P.R. China
| | - Yi-Ran Ma
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, P.R. China
| | - Yu-Xin Zhang
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, P.R. China
| | - Fan-Hao Wei
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, P.R. China
| | - Yi Zheng
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, P.R. China
| | - Zhong-Hao Ji
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, P.R. China
| | - Hai-Xiang Guo
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, P.R. China
| | - Tian Wang
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, P.R. China
| | - Jia-Bao Zhang
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, P.R. China.
| | - Bao Yuan
- Department of Laboratory Animals, College of Animal Sciences, Jilin University, Changchun, Jilin, 130062, P.R. China.
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Fanis P, Neocleous V, Papapetrou I, Phylactou LA, Skordis N. Gonadotropin-Releasing Hormone Receptor (GnRHR) and Hypogonadotropic Hypogonadism. Int J Mol Sci 2023; 24:15965. [PMID: 37958948 PMCID: PMC10650312 DOI: 10.3390/ijms242115965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 10/31/2023] [Accepted: 11/02/2023] [Indexed: 11/15/2023] Open
Abstract
Human sexual and reproductive development is regulated by the hypothalamic-pituitary-gonadal (HPG) axis, which is primarily controlled by the gonadotropin-releasing hormone (GnRH) acting on its receptor (GnRHR). Dysregulation of the axis leads to conditions such as congenital hypogonadotropic hypogonadism (CHH) and delayed puberty. The pathophysiology of GnRHR makes it a potential target for treatments in several reproductive diseases and in congenital adrenal hyperplasia. GnRHR belongs to the G protein-coupled receptor family and its GnRH ligand, when bound, activates several complex and tissue-specific signaling pathways. In the pituitary gonadotrope cells, it triggers the G protein subunit dissociation and initiates a cascade of events that lead to the production and secretion of the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) accompanied with the phospholipase C, inositol phosphate production, and protein kinase C activation. Pharmacologically, GnRHR can be modulated by synthetic analogues. Such analogues include the agonists, antagonists, and the pharmacoperones. The agonists stimulate the gonadotropin release and lead to receptor desensitization with prolonged use while the antagonists directly block the GnRHR and rapidly reduce the sex hormone production. Pharmacoperones include the most recent GnRHR therapeutic approaches that directly correct the misfolded GnRHRs, which are caused by genetic mutations and hold serious promise for CHH treatment. Understanding of the GnRHR's genomic and protein structure is crucial for the most appropriate assessing of the mutation impact. Such mutations in the GNRHR are linked to normosmic hypogonadotropic hypogonadism and lead to various clinical symptoms, including delayed puberty, infertility, and impaired sexual development. These mutations vary regarding their mode of inheritance and can be found in the homozygous, compound heterozygous, or in the digenic state. GnRHR expression extends beyond the pituitary gland, and is found in reproductive tissues such as ovaries, uterus, and prostate and non-reproductive tissues such as heart, muscles, liver and melanoma cells. This comprehensive review explores GnRHR's multifaceted role in human reproduction and its clinical implications for reproductive disorders.
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Affiliation(s)
- Pavlos Fanis
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus; (P.F.); (V.N.)
| | - Vassos Neocleous
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus; (P.F.); (V.N.)
| | - Irene Papapetrou
- School of Medicine, University of Nicosia, Nicosia 1678, Cyprus;
| | - Leonidas A. Phylactou
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, Nicosia 2371, Cyprus; (P.F.); (V.N.)
| | - Nicos Skordis
- School of Medicine, University of Nicosia, Nicosia 1678, Cyprus;
- Division of Paediatric Endocrinology, Paedi Center for Specialized Paediatrics, Nicosia 2024, Cyprus
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3
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Mohammadzadeh P, Roueinfar M, Amberg GC. AXL receptor tyrosine kinase modulates gonadotropin-releasing hormone receptor signaling. Cell Commun Signal 2023; 21:284. [PMID: 37828510 PMCID: PMC10568877 DOI: 10.1186/s12964-023-01313-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 09/09/2023] [Indexed: 10/14/2023] Open
Abstract
BACKGROUND Gonadotropin-releasing hormone (GnRH) receptors are essential for reproduction and are expressed in numerous urogenital, reproductive, and non-reproductive cancers. In addition to canonical G protein-coupled receptor signaling, GnRH receptors functionally interact with several receptor tyrosine kinases. AXL is a receptor tyrosine kinase expressed in numerous tissues as well as multiple tumors. Here we tested the hypothesis that AXL, along with its endogenous ligand Gas6, impacts GnRH receptor signaling. METHODS We used clonal murine pituitary αT3-1 and LβT2 gonadotrope cell lines to examine the effect of AXL activation on GnRH receptor-dependent signaling outcomes. ELISA and immunofluorescence were used to observe AXL and GnRH receptor expression in αT3-1 and LβT2 cells, as well as in murine and human pituitary sections. We also used ELISA to measure changes in ERK phosphorylation, pro-MMP9 production, and release of LHβ. Digital droplet PCR was used to measure the abundance of Egr-1 transcripts. A transwell migration assay was used to measure αT3-1 and LβT2 migration responses to GnRH and AXL. RESULTS We observed AXL, along with the GnRH receptor, expression in αT3-1 and LβT2 gonadotrope cell lines, as well as in murine and human pituitary sections. Consistent with a potentiating role of AXL, Gas6 enhanced GnRH-dependent ERK phosphorylation in αT3-1 and LβT2 cells. Further, and consistent with enhanced post-transcriptional GnRH receptor responses, we found that Gas6 increased the abundance of Egr-1 transcripts. Suggesting functional significance, in LβT2 cells, Gas6/AXL signaling stimulated LHβ production and enhanced GnRH receptor-dependent generation of pro-MMP9 protein and promoted cell migration. CONCLUSIONS Altogether, these data describe a novel role for AXL as a modulator of GnRH receptor signaling. Video Abstract.
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Affiliation(s)
- Pardis Mohammadzadeh
- Department of Biomedical Sciences, Colorado State University, 1617 Campus Delivery, Fort Collins, CO, 80523, USA
| | - Mina Roueinfar
- Department of Biomedical Sciences, Colorado State University, 1617 Campus Delivery, Fort Collins, CO, 80523, USA
| | - Gregory C Amberg
- Department of Biomedical Sciences, Colorado State University, 1617 Campus Delivery, Fort Collins, CO, 80523, USA.
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Kumar M, Goswami M, Nayak SK, Gireesh-Babu P, Chaudhari A. Evaluation of the Binding Affinity of a Gonadotropin-Releasing Hormone
Analogue (GnRH-a) Buserelin through In silico and In vivo Testing in
Clarias magur. CURR PROTEOMICS 2022. [DOI: 10.2174/1570164618666210426090916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aim:
To evaluate the binding affinity and biological potency of gonadotropin-releasing
hormone analogue (GnRHa) Buserelin (C60H86N16O13) based on in silico and in vivo testing for induced
breeding in Clarias magur.
Background:
Many attempts have been made to induce C. magur, but encouraging results have
not yet been achieved. Hence, it is the need of the hour to find out more potent analogues or other
bio-molecules for induced breeding in C. magur to facilitate sustainable aquaculture.
Objective:
To determine the binding affinity of C. magur GnRH receptor through in silico and to
validate it for induced breeding of C. magur.
Methods:
Buserelin (C60H86N16O13) was selected as the potential GnRHa after screening several peptides
for their binding energy with the C. magur GnRH receptor. The induced breeding trial was set
up at ICAR-CIFE Powarkheda Centre, M.P. India, and Buserelin was administered in different doses
to the brooders along with the dopamine inhibitor domperidone. The standard treatment with the
commercial salmon GnRH (sGnRH) analogue Ovaprim® (Syndel, USA) was used as the control.
Results:
The 3-D structure of C. magur GnRH receptor was generated using MODELLER software.
Molecular docking studies revealed the binding preference of the receptor as chicken (c) Gn-
RH-II > Buserelin > sGnRH > catfish (cf) GnRH > human (m) GnRH. Though Buserelin showed
better binding affinity compared to sGnRH, induced breeding experiments with magur showed similar
performance of the ligands at the equivalent dose of 20 μg/kg B.W., but the spontaneous release
of milt from the males was not observed in both cases. Significantly better reproductive parameters
were recorded with Buserelin at the dose of 30 μg/kg B.W.
Conclusion:
The study revealed that that the GnRHa Buserelin can be used as an effective inducing
agent for breeding in C. magur.
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Affiliation(s)
- Mukesh Kumar
- Fish Genetics & Biotechnology Division, ICAR-Central Institute of Fisheries Education, Mumbai - 400 061 India
| | - Mukunda Goswami
- Fish Genetics & Biotechnology Division, ICAR-Central Institute of Fisheries Education, Mumbai - 400 061 India
| | - Sunil Kumar Nayak
- Fish Genetics & Biotechnology Division, ICAR-Central Institute of Fisheries Education, Mumbai - 400 061 India
| | - P. Gireesh-Babu
- Fish Genetics & Biotechnology Division, ICAR-Central Institute of Fisheries Education, Mumbai - 400 061 India
| | - Aparna Chaudhari
- Fish Genetics & Biotechnology Division, ICAR-Central Institute of Fisheries Education, Mumbai - 400 061 India
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Khalid E, Chang JP. Receptor-proximal effectors mediating GnRH actions in the goldfish pituitary: Involvement of G protein subunits and GRKs. Gen Comp Endocrinol 2022; 319:113991. [PMID: 35157923 DOI: 10.1016/j.ygcen.2022.113991] [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: 11/17/2021] [Revised: 02/01/2022] [Accepted: 02/09/2022] [Indexed: 11/21/2022]
Abstract
In goldfish (Carassius auratus), two endogenous isoforms of gonadotropin-releasing hormone (GnRH) stimulate luteinizing hormone (LH) and growth hormone (GH) secretion. These isoforms, GnRH2 and GnRH3, act on a shared population of cell-surface GnRH receptors (GnRHRs) expressed on both gonadotrophs and somatotrophs, and can signal through unique, yet partially overlapping, suites of intracellular effectors, in a phenomenon known as functional selectivity or biased signalling. In this study, G-protein alpha (Gα) subunits were targeted with two inhibitors, YM-254890 and BIM-46187, to ascertain the contribution of specific G-protein subunits in GnRH signalling. Results with the Gαq/11-specific inhibitor YM-254890 on primary cultures of goldfish pituitary cells revealed the use of these subunits in GnRH control of both LH and GH release, as well as GnRH-induced elevations in phospho-ERK levels. Results with the pan-Gα inhibitor BIM-46187 matched those using YM-254890 in LH release but GH responses differed, indicating additional, non-Gαq/11 subunits may be involved in somatotrophs. BIM-46187 also elevated unstimulated LH and GH release suggesting that Gα subunits regulate basal hormone secretion. Furthermore, G-protein-coupled receptor kinase (GRK2/3) inhibition reduced LH responses to GnRH2 and GnRH3, and selectively enhanced GnRH2-stimulated GH release, indicating differential use of GRK2/3 in GnRH actions on gonadotrophs and somatotrophs. These findings in a primary untransformed system provide the first direct evidence to establish Gαq/11 as an obligate driver of GnRH signalling in goldfish pituitary cells, and additionally describe the differential agonist- and cell type-selective involvement of GRK2/3 in this system.
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Affiliation(s)
- Enezi Khalid
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G2E9, Canada
| | - John P Chang
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G2E9, Canada.
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Murata T, Chiba S, Kawaminami M. The expression of Annexin A1 and A5 mRNA by gonadotropin-releasing hormone in LβT2 gonadotrope cells. Endocr J 2022; 69:283-290. [PMID: 34645720 DOI: 10.1507/endocrj.ej21-0397] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) stimulation of annexin A1 (ANXA1) and A5 (ANXA5) mRNA expression was analyzed in LβT2 gonadotrope cells. Quantitative polymerase chain reaction results showed that a GnRH analog (GnRHa) stimulated the expression of both ANXA1 and A5 mRNA with a peak at 12 h of incubation; however, ANXA1 mRNA was extremely stimulated (60 folds). Immunocytochemical analysis confirmed these findings. A GnRH antagonist inhibited the effect of GnRHa. ANXA1 and A5 mRNA levels were significantly increased by protein kinase C (PKC) activator (12-O-Tetradecanoylphorbol-13-acetate; TPA), but not by dibutyryl cAMP. GnRHa-stimulated induction of ANXA1 and A5 mRNA was inhibited by PKC (GF109203) and MEK inhibitors (PD98059). TPA increased ANXA1 and A5 mRNA expression in a dose-dependent manner (1 nM to 10 μM), while the extent of the increase was much greater in ANXA1. After stimulation with 10 nM or 1 μM TPA, ANXA1 and A5 mRNA levels were increased at 6 h. ANXA1 mRNA levels were higher in the 1 μM TPA than in the 10 nM TPA treatment, whereas 1 μM TPA did not show further stimulation of ANXA5 mRNA compared to 10 nM TPA. These results clearly show that ANXA1 mRNA expression is stimulated by GnRH through PKC like ANXA5, and the response of ANXA1 is much larger than that of ANXA5. A close relationship between these annexins and a significant role for ANXA1 in GnRH action at gonadotropes is suggested.
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Affiliation(s)
- Takuya Murata
- Laboratory of Veterinary Physiology, Faculty of Veterinary Medicine, Okayama University of Science, Ehime 794-8555, Japan
| | - Shuichi Chiba
- Laboratory of Veterinary Physiology, Faculty of Veterinary Medicine, Okayama University of Science, Ehime 794-8555, Japan
| | - Mitsumori Kawaminami
- Laboratory of Veterinary Physiology, Faculty of Veterinary Medicine, Okayama University of Science, Ehime 794-8555, Japan
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Stamatiades GA, Toufaily C, Kim HK, Zhou X, Thompson IR, Carroll RS, Chen M, Weinstein LS, Offermanns S, Boehm U, Bernard DJ, Kaiser UB. Deletion of Gαq/11 or Gαs Proteins in Gonadotropes Differentially Affects Gonadotropin Production and Secretion in Mice. Endocrinology 2022; 163:6453384. [PMID: 34864945 PMCID: PMC8711759 DOI: 10.1210/endocr/bqab247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Indexed: 11/19/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) regulates gonadal function via its stimulatory effects on gonadotropin production by pituitary gonadotrope cells. GnRH is released from the hypothalamus in pulses and GnRH pulse frequency differentially regulates follicle-stimulating hormone (FSH) and luteinizing hormone (LH) synthesis and secretion. The GnRH receptor (GnRHR) is a G protein-coupled receptor that canonically activates Gα q/11-dependent signaling on ligand binding. However, the receptor can also couple to Gα s and in vitro data suggest that toggling between different G proteins may contribute to GnRH pulse frequency decoding. For example, as we show here, knockdown of Gα s impairs GnRH-stimulated FSH synthesis at low- but not high-pulse frequency in a model gonadotrope-derived cell line. We next used a Cre-lox conditional knockout approach to interrogate the relative roles of Gα q/11 and Gα s proteins in gonadotrope function in mice. Gonadotrope-specific Gα q/11 knockouts exhibit hypogonadotropic hypogonadism and infertility, akin to the phenotypes seen in GnRH- or GnRHR-deficient mice. In contrast, under standard conditions, gonadotrope-specific Gα s knockouts produce gonadotropins at normal levels and are fertile. However, the LH surge amplitude is blunted in Gα s knockout females and postgonadectomy increases in FSH and LH are reduced both in males and females. These data suggest that GnRH may signal principally via Gα q/11 to stimulate gonadotropin production, but that Gα s plays important roles in gonadotrope function in vivo when GnRH secretion is enhanced.
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Affiliation(s)
- George A Stamatiades
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
- University of Crete, School of Medicine, 71500 Heraklion, Greece
| | - Chirine Toufaily
- Dept. of Pharmacology and Therapeutics, McGill University, H3G 1Y6 Québec, Canada
| | - Han Kyeol Kim
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Xiang Zhou
- Dept. of Pharmacology and Therapeutics, McGill University, H3G 1Y6 Québec, Canada
| | - Iain R Thompson
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Rona S Carroll
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Min Chen
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20814, USA
| | - Lee S Weinstein
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20814, USA
| | - Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Ulrich Boehm
- Experimental Pharmacology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, 66424 Homburg, Germany
| | - Daniel J Bernard
- Dept. of Pharmacology and Therapeutics, McGill University, H3G 1Y6 Québec, Canada
| | - Ursula B Kaiser
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
- Correspondence: Ursula B. Kaiser, MD, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, 221 Longwood Ave, Boston, MA 02115, USA.
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Kim JW, Park M, Kim S, Lim SC, Kim HS, Kang KW. Anti-metastatic effect of GV1001 on prostate cancer cells; roles of GnRHR-mediated Gαs-cAMP pathway and AR-YAP1 axis. Cell Biosci 2021. [PMID: 34743733 DOI: 10.1186/s13578-021-00704-3.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Gonadotropin-releasing hormone receptor (GnRHR) transmits its signal via two major Gα-proteins, primarily Gαq and Gαi. However, the precise mechanism underlying the functions of Gαs signal in prostate cancer cells is still unclear. We have previously identified that GV1001, a fragment of the human telomerase reverse transcriptase, functions as a biased GnRHR ligand to selectively stimulate the Gαs/cAMP pathway. Here, we tried to reveal the potential mechanisms of which GV1001-stimulated Gαs-cAMP signaling pathway reduces the migration and metastasis of prostate cancer (PCa) cells. METHODS The expression of epithelial-mesenchymal transition (EMT)-related genes was measured by western-blotting and spheroid formation on ultra-low attachment plate was detected after GV1001 treatment. In vivo Spleen-liver metastasis mouse model was used to explore the inhibitory effect of GV1001 on metastatic ability of PCa and the transwell migration assay was performed to identify whether GV1001 had a suppressive effect on cell migration in vitro. In order to demonstrate the interaction between androgen receptor (AR) and YAP1, co-immunoprecipitation (co-IP), immunofluorescence (IF) staining, chromatin immunoprecipitation (ChIP) were performed in LNCaP cells with and without GV1001 treatment. RESULTS GV1001 inhibited expression of EMT-related genes and spheroid formation. GV1001 also suppressed in vivo spleen-liver metastasis of LNCaP cells as well as cell migration in vitro. GV1001 enhanced the phosphorylation of AR and transcription activity of androgen response element reporter gene through cAMP/protein kinase A pathway. Moreover, GV1001 increased Ser-127 phosphorylation of YAP1 and its ubiquitination, and subsequently decreased the levels of AR-YAP1 binding in the promoter region of the CTGF gene. In contrast, both protein and mRNA levels of NKX3.1 known for tumor suppressor gene and AR-coregulator were upregulated by GV1001 in LNCaP cells. YAP1 knockout using CRISPR/Cas9 significantly suppressed the migration ability of LNCaP cells, and GV1001 did not affect the cell migration of YAP1-deficient LNCaP cells. On the contrary, cell migration was more potentiated in LNCaP cells overexpressing YAP5SA, a constitutively active form of YAP1, which was not changed by GV1001 treatment. CONCLUSIONS Overall, this study reveals an essential role of AR-YAP1 in the regulation of PCa cell migration, and provides evidence that GV1001 could be a novel GnRHR ligand to inhibit metastasis of PCa via the Gαs/cAMP pathway.
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Affiliation(s)
- Ji Won Kim
- Division of Hematology and Medical Oncology, University of California, San Francisco, CA, 94143, USA
| | - Miso Park
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Suntae Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sung Chul Lim
- Department of Pathology, College of Medicine, Chosun University, Gwangju, 61452, Republic of Korea
| | - Hyung Shik Kim
- College of Pharmacy, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Keon Wook Kang
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
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Kim JW, Park M, Kim S, Lim SC, Kim HS, Kang KW. Anti-metastatic effect of GV1001 on prostate cancer cells; roles of GnRHR-mediated Gαs-cAMP pathway and AR-YAP1 axis. Cell Biosci 2021; 11:191. [PMID: 34743733 PMCID: PMC8574053 DOI: 10.1186/s13578-021-00704-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/29/2021] [Indexed: 11/16/2022] Open
Abstract
Background Gonadotropin-releasing hormone receptor (GnRHR) transmits its signal via two major Gα-proteins, primarily Gαq and Gαi. However, the precise mechanism underlying the functions of Gαs signal in prostate cancer cells is still unclear. We have previously identified that GV1001, a fragment of the human telomerase reverse transcriptase, functions as a biased GnRHR ligand to selectively stimulate the Gαs/cAMP pathway. Here, we tried to reveal the potential mechanisms of which GV1001-stimulated Gαs-cAMP signaling pathway reduces the migration and metastasis of prostate cancer (PCa) cells. Methods The expression of epithelial-mesenchymal transition (EMT)-related genes was measured by western-blotting and spheroid formation on ultra-low attachment plate was detected after GV1001 treatment. In vivo Spleen-liver metastasis mouse model was used to explore the inhibitory effect of GV1001 on metastatic ability of PCa and the transwell migration assay was performed to identify whether GV1001 had a suppressive effect on cell migration in vitro. In order to demonstrate the interaction between androgen receptor (AR) and YAP1, co-immunoprecipitation (co-IP), immunofluorescence (IF) staining, chromatin immunoprecipitation (ChIP) were performed in LNCaP cells with and without GV1001 treatment. Results GV1001 inhibited expression of EMT-related genes and spheroid formation. GV1001 also suppressed in vivo spleen-liver metastasis of LNCaP cells as well as cell migration in vitro. GV1001 enhanced the phosphorylation of AR and transcription activity of androgen response element reporter gene through cAMP/protein kinase A pathway. Moreover, GV1001 increased Ser-127 phosphorylation of YAP1 and its ubiquitination, and subsequently decreased the levels of AR-YAP1 binding in the promoter region of the CTGF gene. In contrast, both protein and mRNA levels of NKX3.1 known for tumor suppressor gene and AR-coregulator were upregulated by GV1001 in LNCaP cells. YAP1 knockout using CRISPR/Cas9 significantly suppressed the migration ability of LNCaP cells, and GV1001 did not affect the cell migration of YAP1-deficient LNCaP cells. On the contrary, cell migration was more potentiated in LNCaP cells overexpressing YAP5SA, a constitutively active form of YAP1, which was not changed by GV1001 treatment. Conclusions Overall, this study reveals an essential role of AR-YAP1 in the regulation of PCa cell migration, and provides evidence that GV1001 could be a novel GnRHR ligand to inhibit metastasis of PCa via the Gαs/cAMP pathway. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-021-00704-3.
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Affiliation(s)
- Ji Won Kim
- Division of Hematology and Medical Oncology, University of California, San Francisco, CA, 94143, USA
| | - Miso Park
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Suntae Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sung Chul Lim
- Department of Pathology, College of Medicine, Chosun University, Gwangju, 61452, Republic of Korea
| | - Hyung Shik Kim
- College of Pharmacy, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Keon Wook Kang
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
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Kotarba G, Zielinska-Gorska M, Biernacka K, Gajewska A. Gonadotropin-releasing hormone-Cu complex (Cu-GnRH) transcriptional activity in vivo in the female rat anterior pituitary gland. Brain Res Bull 2020; 156:67-75. [PMID: 31931118 DOI: 10.1016/j.brainresbull.2020.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 12/23/2019] [Accepted: 01/03/2020] [Indexed: 12/01/2022]
Abstract
Unlike gonadotropin-releasing hormone (GnRH) analogues characterized by amino acid replacement in decapeptide primary structure, Cu-GnRH molecule preserves the native sequence but contains a Cu2+ ion stably bound to the nitrogen atoms including that of the imidazole ring of His2. Cu-GnRH can operate via cAMP/PKA signalling in anterior pituitary cells, suggesting that it may affect selected gonadotropic network gene transcription in vivo. We analysed pituitary mRNA expression of Egr-1, Nr5a1, and Lhb based on their role in luteinizing hormone (LH) synthesis; and Nos1, Adcyap1, and Prkaca due to their dependence on cAMP/PKA activity. In two independent experiments, ovariectomized rats received intracerebroventricular pulsatile (one pulse/h or two pulses/h over 5 h) microinjections of 2 nM Cu-GnRH; 2 nM antide (GnRH antagonist) + 2 nM Cu-GnRH; 100 nM PACAP6-38 (PACAP receptor antagonist) + 2 nM Cu-GnRH. Relative expression of selected mRNAs was determined by qRT-PCR. LH serum concentration was examined according to RIA. All examined genes responded to Cu-GnRH stimulation with increased transcriptional activity in a manner dependent on pulse frequency pattern. Increased expression of Nr5a1, Lhb, Nos1, Adcyap1, and Prkaca mRNA was observed solely in rats receiving the complex with frequency of two pulses/h over 5 h. Egr-1 transcription was up-regulated for both applied Cu-GnRH pulsatile patterns. The stimulatory effect of Cu-GnRH on gene transcription was dependent on both GnRH receptor and PAC-1 activation. In conclusion, obtained results indicate that Cu-GnRH complex is a GnRH analogue able to induce both IP3/PKC and cAMP/PKA-dependent gonadotrope network gene transcription in vivo.
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Affiliation(s)
- Grzegorz Kotarba
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 3 Instytucka St., 05-110 Jablonna, Poland.
| | - Marlena Zielinska-Gorska
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 3 Instytucka St., 05-110 Jablonna, Poland.
| | - Katarzyna Biernacka
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 3 Instytucka St., 05-110 Jablonna, Poland
| | - Alina Gajewska
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 3 Instytucka St., 05-110 Jablonna, Poland.
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GnRH Antagonists Produce Differential Modulation of the Signaling Pathways Mediated by GnRH Receptors. Int J Mol Sci 2019; 20:ijms20225548. [PMID: 31703269 PMCID: PMC6888270 DOI: 10.3390/ijms20225548] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 12/13/2022] Open
Abstract
Commercial gonadotropin-releasing hormone (GnRH) antagonists differ by 1-2 amino acids and are used to inhibit gonadotropin production during assisted reproduction technologies (ART). In this study, potencies of three GnRH antagonists, Cetrorelix, Ganirelix and Teverelix, in inhibiting GnRH-mediated intracellular signaling, were compared in vitro. GnRH receptor (GnRHR)-transfected HEK293 and neuroblastoma-derived SH-SY5Y cell lines, as well as mouse pituitary LβT2 cells endogenously expressing the murine GnRHR, were treated with GnRH in the presence or absence of the antagonist. We evaluated intracellular calcium (Ca2+) and cAMP increases, cAMP-responsive element binding-protein (CREB) and extracellular-regulated kinase 1 and 2 (ERK1/2) phosphorylation, β-catenin activation and mouse luteinizing-hormone β-encoding gene (Lhb) transcription by bioluminescence resonance energy transfer (BRET), Western blotting, immunostaining and real-time PCR as appropriate. The kinetics of GnRH-induced Ca2+ rapid increase revealed dose-response accumulation with potency (EC50) of 23 nM in transfected HEK293 cells, transfected SH-SY5Y and LβT2 cells. Cetrorelix inhibited the 3 × EC50 GnRH-activated calcium signaling at concentrations of 1 nM-1 µM, demonstrating higher potency than Ganirelix and Teverelix, whose inhibitory doses fell within the 100 nM-1 µM range in both transfected HEK293 and SH-SY5Y cells in vitro. In transfected SH-SY5Y, Cetrorelix was also significantly more potent than other antagonists in reducing GnRH-mediated cAMP accumulation. All antagonists inhibited pERK1/2 and pCREB activation at similar doses, in LβT2 and transfected HEK293 cells treated with 100 nM GnRH. Although immunostainings suggested that Teverelix could be less effective than Cetrorelix and Ganirelix in inhibiting 1 µM GnRH-induced β-catenin activation, Lhb gene expression increase occurring upon LβT2 cell treatment by 1 µM GnRH was similarly inhibited by all antagonists. To conclude, this study has demonstrated Cetrorelix-, Ganirelix- and Teverelix-specific biased effects at the intracellular level, not affecting the efficacy of antagonists in inhibiting Lhb gene transcription.
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Dufour S, Quérat B, Tostivint H, Pasqualini C, Vaudry H, Rousseau K. Origin and Evolution of the Neuroendocrine Control of Reproduction in Vertebrates, With Special Focus on Genome and Gene Duplications. Physiol Rev 2019; 100:869-943. [PMID: 31625459 DOI: 10.1152/physrev.00009.2019] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In humans, as in the other mammals, the neuroendocrine control of reproduction is ensured by the brain-pituitary gonadotropic axis. Multiple internal and environmental cues are integrated via brain neuronal networks, ultimately leading to the modulation of the activity of gonadotropin-releasing hormone (GnRH) neurons. The decapeptide GnRH is released into the hypothalamic-hypophysial portal blood system and stimulates the production of pituitary glycoprotein hormones, the two gonadotropins luteinizing hormone and follicle-stimulating hormone. A novel actor, the neuropeptide kisspeptin, acting upstream of GnRH, has attracted increasing attention in recent years. Other neuropeptides, such as gonadotropin-inhibiting hormone/RF-amide related peptide, and other members of the RF-amide peptide superfamily, as well as various nonpeptidic neuromediators such as dopamine and serotonin also provide a large panel of stimulatory or inhibitory regulators. This paper addresses the origin and evolution of the vertebrate gonadotropic axis. Brain-pituitary neuroendocrine axes are typical of vertebrates, the pituitary gland, mediator and amplifier of brain control on peripheral organs, being a vertebrate innovation. The paper reviews, from molecular and functional perspectives, the evolution across vertebrate radiation of some key actors of the vertebrate neuroendocrine control of reproduction and traces back their origin along the vertebrate lineage and in other metazoa before the emergence of vertebrates. A focus is given on how gene duplications, resulting from either local events or from whole genome duplication events, and followed by paralogous gene loss or conservation, might have shaped the evolutionary scenarios of current families of key actors of the gonadotropic axis.
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Affiliation(s)
- Sylvie Dufour
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
| | - Bruno Quérat
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
| | - Hervé Tostivint
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
| | - Catherine Pasqualini
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
| | - Hubert Vaudry
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
| | - Karine Rousseau
- Muséum National d'Histoire Naturelle, Biology of Aquatic Organisms and Ecosystems, CNRS, IRD, Sorbonne Université, Université Caen Normandie, Université des Antilles, Paris, France; Université Paris Diderot, Sorbonne Paris Cite, Biologie Fonctionnelle et Adaptative, Paris, France; INSERM U1133, Physiologie de l'axe Gonadotrope, Paris, France; Muséum National d'Histoire Naturelle, Physiologie Moléculaire et Adaptation, Muséum National d'Histoire Naturelle, Paris, France; Université Paris-Saclay, Université Paris-Sud, CNRS, Paris-Saclay Institute of Neuroscience (UMR 9197), Gif-sur-Yvette, France; and Université de Rouen Normandie, Rouen, France
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Macedo G, Mingoti R, Batista E, Monteiro B, Vieira L, Barletta R, Wiltbank M, Nogueira G, Rennó F, Maio J, Baruselli P. Profile of LH release in response to intramuscular treatment with kisspeptin in Bos indicus and Bos taurus prepubertal heifers. Theriogenology 2019; 125:64-70. [DOI: 10.1016/j.theriogenology.2018.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 10/07/2018] [Accepted: 10/10/2018] [Indexed: 12/13/2022]
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Son YL, Ubuka T, Tsutsui K. Molecular Mechanisms of Gonadotropin-Inhibitory Hormone (GnIH) Actions in Target Cells and Regulation of GnIH Expression. Front Endocrinol (Lausanne) 2019; 10:110. [PMID: 30858828 PMCID: PMC6397841 DOI: 10.3389/fendo.2019.00110] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 02/06/2019] [Indexed: 11/13/2022] Open
Abstract
Since gonadotropin-inhibitory hormone (GnIH) was discovered in 2000 as the first hypothalamic neuropeptide that actively inhibits gonadotropin release, researches conducted for the last 18 years have demonstrated that GnIH acts as a pronounced negative regulator of reproduction. Inhibitory effect of GnIH on reproduction is mainly accomplished at hypothalamic-pituitary levels; gonadotropin-releasing hormone (GnRH) neurons and gonadotropes are major targets of GnIH action based on the morphological interaction with GnIH neuronal fibers and the distribution of GnIH receptor. Here, we review molecular studies mainly focusing on the signal transduction pathway of GnIH in target cells, GnRH neurons, and gonadotropes. The use of well-defined cellular model systems allows the mechanistic study of signaling pathway occurring in target cells by demonstrating the direct cause-and-effect relationship. The insights gained through studying molecular mechanism of GnIH action contribute to deeper understanding of the mechanism of how GnIH communicates with other neuronal signaling systems to control our reproductive function. Reproductive axis closely interacts with other endocrine systems, thus GnIH expression levels would be changed by adrenal and thyroid status. We also briefly review molecular studies investigating the regulatory mechanisms of GnIH expression to understand the role of GnIH as a mediator between adrenal, thyroid and gonadal axes.
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Affiliation(s)
- You Lee Son
- Laboratory of Photobiology, Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
- Laboratory of Integrative Brain Sciences, Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan
- *Correspondence: You Lee Son
| | - Takayoshi Ubuka
- Laboratory of Integrative Brain Sciences, Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan
| | - Kazuyoshi Tsutsui
- Laboratory of Integrative Brain Sciences, Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan
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15
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Abstract
The hypothalamic decapeptide, GnRH, is the gatekeeper of mammalian reproductive development and function. Activation of specific, high-affinity cell surface receptors (GnRH receptors) on gonadotropes by GnRH triggers signal transduction cascades to stimulate the coordinated synthesis and secretion of the pituitary gonadotropins FSH and LH. These hormones direct gonadal steroidogenesis and gametogenesis, making their tightly regulated production and secretion essential for normal sexual maturation and reproductive health. FSH and LH are glycoprotein heterodimers comprised of a common α-subunit and a unique β-subunit (FSHβ and LHβ, respectively), which determines the biological specificity of the gonadotropins. The unique β-subunit is the rate-limiting step for the production of the mature gonadotropins. Therefore, FSH synthesis is regulated at the transcriptional level by Fshb gene expression. The overarching goal of this review is to expand our understanding of the mechanisms and pathways underlying the carefully orchestrated control of FSH synthesis and secretion by GnRH, focusing on the transcriptional regulation of the Fshb gene. Identification of these regulatory mechanisms is not only fundamental to our understanding of normal reproductive function but will also provide a context for the elucidation of the pathophysiology of reproductive disorders and infertility to lead to potential new therapeutic approaches.
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Affiliation(s)
- George A Stamatiades
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
- Yale New Haven Health, Bridgeport Hospital, Bridgeport, Connecticut
- School of Medicine, University of Crete, Heraklion, Greece
| | - Rona S Carroll
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ursula B Kaiser
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
- Correspondence: Ursula B. Kaiser, MD, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, 221 Longwood Avenue, Boston, Massachusetts 02115. E-mail:
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16
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Kaprara A, Huhtaniemi IT. The hypothalamus-pituitary-gonad axis: Tales of mice and men. Metabolism 2018; 86:3-17. [PMID: 29223677 DOI: 10.1016/j.metabol.2017.11.018] [Citation(s) in RCA: 168] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 11/28/2017] [Accepted: 11/29/2017] [Indexed: 02/06/2023]
Abstract
Reproduction is controlled by the hypothalamic-pituitary-gonadal (HPG) axis. Gonadotropin-releasing hormone (GnRH) neurons play a central role in this axis through production of GnRH, which binds to a membrane receptor on pituitary gonadotrophs and stimulates the biosynthesis and secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Multiple factors affect GnRH neuron migration, GnRH gene expression, GnRH pulse generator, GnRH secretion, GnRH receptor expression, and gonadotropin synthesis and release. Among them anosmin is involved in the guidance of the GnRH neuron migration, and a loss-of-function mutation in its gene leads to a failure of their migration from the olfactory placode to the hypothalamus, with consequent anosmic hypogonadotropic hypogonadism (Kallmann syndrome). There are also cases of hypogonadotropic hypogonadim with normal sense of smell, due to mutations of other genes. Another protein, kisspeptin plays a crucial role in the regulation of GnRH pulse generator and the pubertal development. GnRH is the main hypothalamic regulator of the release of gonadotropins. Finally, FSH and LH are the essential hormonal regulators of testicular functions, acting through their receptors in Sertoli and Leydig cells, respectively. The main features of the male HPG axis will be described in this review.
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Affiliation(s)
- Athina Kaprara
- Unit of Reproductive Endocrinology, Medical School, Aristotle University of Thessaloniki, Greece.
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17
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Dang AK, Chaplin NL, Murtazina DA, Boehm U, Clay CM, Amberg GC. Subplasmalemmal hydrogen peroxide triggers calcium influx in gonadotropes. J Biol Chem 2018; 293:16028-16042. [PMID: 30154243 DOI: 10.1074/jbc.ra118.001830] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 08/14/2018] [Indexed: 01/01/2023] Open
Abstract
Gonadotropin-releasing hormone (GnRH) stimulation of its eponymous receptor on the surface of endocrine anterior pituitary gonadotrope cells (gonadotropes) initiates multiple signaling cascades that culminate in the secretion of luteinizing and follicle-stimulating hormones, which have critical roles in fertility and reproduction. Enhanced luteinizing hormone biosynthesis, a necessary event for ovulation, requires a signaling pathway characterized by calcium influx through L-type calcium channels and subsequent activation of the mitogen-activated protein kinase extracellular signal-regulated kinase (ERK). We previously reported that highly localized subplasmalemmal calcium microdomains produced by L-type calcium channels (calcium sparklets) play an essential part in GnRH-dependent ERK activation. Similar to calcium, reactive oxygen species (ROS) are ubiquitous intracellular signaling molecules whose subcellular localization determines their specificity. To investigate the potential influence of oxidant signaling in gonadotropes, here we examined the impact of ROS generation on L-type calcium channel function. Total internal reflection fluorescence (TIRF) microscopy revealed that GnRH induces spatially restricted sites of ROS generation in gonadotrope-derived αT3-1 cells. Furthermore, GnRH-dependent stimulation of L-type calcium channels required intracellular hydrogen peroxide signaling in these cells and in primary mouse gonadotropes. NADPH oxidase and mitochondrial ROS generation were each necessary for GnRH-mediated stimulation of L-type calcium channels. Congruently, GnRH increased oxidation within subplasmalemmal mitochondria, and L-type calcium channel activity correlated strongly with the presence of adjacent mitochondria. Collectively, our results provide compelling evidence that NADPH oxidase activity and mitochondria-derived hydrogen peroxide signaling play a fundamental role in GnRH-dependent stimulation of L-type calcium channels in anterior pituitary gonadotropes.
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Affiliation(s)
- An K Dang
- From the Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523 and
| | - Nathan L Chaplin
- From the Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523 and
| | - Dilyara A Murtazina
- From the Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523 and
| | - Ulrich Boehm
- Department of Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, 66421 Homburg, Germany
| | - Colin M Clay
- From the Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523 and
| | - Gregory C Amberg
- From the Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523 and
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18
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Wang W, Chen ZX, Guo DY, Tao YX. Regulation of prostate cancer by hormone-responsive G protein-coupled receptors. Pharmacol Ther 2018; 191:135-147. [PMID: 29909235 DOI: 10.1016/j.pharmthera.2018.06.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/01/2018] [Indexed: 11/27/2022]
Abstract
Regulation of prostate cancer by androgen and androgen receptor (AR), and blockade of AR signaling by AR antagonists and steroidogenic enzyme inhibitors have been extensively studied. G protein-coupled receptors (GPCRs) are a family of membrane receptors that regulate almost all physiological processes. Nearly 40% of FDA-approved drugs in the market target GPCRs. A variety of GPCRs that mediate reproductive function have been demonstrated to be involved in the regulation of prostate cancer. These GPCRs include gonadotropin-releasing hormone receptor, luteinizing hormone receptor, follicle-stimulating hormone receptor, relaxin receptor, ghrelin receptor, and kisspeptin receptor. We highlight here GPCR regulation of prostate cancer by these GPCRs. Further therapeutic approaches targeting these GPCRs for the treatment of prostate cancer are summarized.
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Affiliation(s)
- Wei Wang
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
| | - Zhao-Xia Chen
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
| | - Dong-Yu Guo
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China.
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA.
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Moon KT, Yoo TK, Kwon SY, Ha JY, Byun SS, Kim JH, Chung JI, Kim TH, Moon HS, Kim SJ, Lee KS. A randomised, placebo-controlled, multicentre, Phase 2 clinical trial to evaluate the efficacy and safety of GV1001 in patients with benign prostatic hyperplasia. BJU Int 2018; 122:283-292. [PMID: 29633507 DOI: 10.1111/bju.14233] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES To evaluate the efficacy and safety of three dosing schemes of GV1001 in patients with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS Eligible patients were men aged ≥50 years, with an International Prostate Symptom Score (IPSS) of ≥13, maximum urinary flow rate (Qmax ) of 5-15 mL/s, post-void residual urine volume (PVR) of ≤200 mL, and prostate volume of ≥30 mL. After a 4 week run-in period, patients were randomly assigned to one of three treatment schedules: Group 1, GV1001 0.4 mg, 2-week interval; Group 2, GV1001 0.56 mg, 2-week interval; Group 3, GV1001 0.56 mg, 4-week interval) or placebo (Group 4). The eligible patients were administered GV1001 or placebo, for a total of seven intradermal injections that were administered at 2-week intervals at weeks 0, 2, 4, 6, 8, 10, and 12. Treatment continued for 12 weeks, and efficacy was evaluated at weeks 4, 8, 12, 13, and 16. Safety was evaluated throughout the 16-week period. The primary efficacy variable was change from baseline (CFB) in total IPSS. Secondary endpoints were CFB in Qmax , PVR, prostate volume, International Index of Erectile Function score, plasma testosterone level, dihydrotestosterone level, and prostate-specific antigen level. RESULTS A total of 161 patients were included (Group 1, n = 41; Groups 2-4, n = 40). Most patients (88.8%) received all planned doses of the study treatment. At week 13, a statistically significant difference in the mean CFB in IPSS was seen in GV1001 treatment Groups 1 and 2 vs the control group for the full analysis population (-3.5 [control] vs -7.2 and -6.8 in Groups 1 and 2, respectively; both P < 0.05). There were also statistically significant differences in CFB at weeks 8, 12, 13, and 16 in treatment Groups 1 and 2 vs control in the per-protocol population. There was a statistically significant reduction in prostate gland volume at week 16 vs control in all treatment groups (0.8 [control] vs -4.6, -2.5, and -4.2 mL in Groups 1-3, respectively; all P < 0.05). There were no statistically significant differences found in other secondary outcome measures. Adverse event (AE) reporting was similar across all four groups. No treatment-emergent AEs were considered to be related to the study drug. CONCLUSIONS The results indicate that GV1001 was effective and well tolerated, and may provide potential beneficial effects in patients with BPH. Compared with medical therapies that require daily dosing, the convenient dosing regimen of GV1001 may provide greater patient adherence. Further investigation of these observations will require large-scale clinical evaluation.
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Affiliation(s)
- Kyong Tae Moon
- Department of Urology, Eulji General Hospital, Eulji University School of Medicine, Seoul, Korea
| | - Tag Keun Yoo
- Department of Urology, Eulji General Hospital, Eulji University School of Medicine, Seoul, Korea
| | - Se Yun Kwon
- Department of Urology, Dongguk University Gyeongju Hospital, Dongguk University College of Medicine, Gyeongju, Korea
| | - Ji Yong Ha
- Department of Urology, Keimyung University School of Medicine, Daegu, Korea
| | - Seok Soo Byun
- Department of Urology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Jang Hwan Kim
- Departments of Urology, Yonsei University College of Medicine, Seoul, Korea
| | - Jae Il Chung
- Department of Urology, Busan Paik Hospital, Inje University, Busan, Korea
| | - Tae Hyoung Kim
- Department of Urology, College of Medicine, ChungAng University, Seoul, Korea
| | - Hong Sang Moon
- Department of Urology, Hanyang University College of Medicine, Seoul, Korea
| | | | - Kyung Seop Lee
- Department of Urology, Dongguk University Gyeongju Hospital, Dongguk University College of Medicine, Gyeongju, Korea
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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: 113] [Impact Index Per Article: 18.8] [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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Flanagan CA, Manilall A. Gonadotropin-Releasing Hormone (GnRH) Receptor Structure and GnRH Binding. Front Endocrinol (Lausanne) 2017; 8:274. [PMID: 29123501 PMCID: PMC5662886 DOI: 10.3389/fendo.2017.00274] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 09/28/2017] [Indexed: 12/22/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) regulates reproduction. The human GnRH receptor lacks a cytoplasmic carboxy-terminal tail but has amino acid sequence motifs characteristic of rhodopsin-like, class A, G protein-coupled receptors (GPCRs). This review will consider how recent descriptions of X-ray crystallographic structures of GPCRs in inactive and active conformations may contribute to understanding GnRH receptor structure, mechanism of activation and ligand binding. The structures confirmed that ligands bind to variable extracellular surfaces, whereas the seven membrane-spanning α-helices convey the activation signal to the cytoplasmic receptor surface, which binds and activates heterotrimeric G proteins. Forty non-covalent interactions that bridge topologically equivalent residues in different transmembrane (TM) helices are conserved in class A GPCR structures, regardless of activation state. Conformation-independent interhelical contacts account for a conserved receptor protein structure and their importance in the GnRH receptor structure is supported by decreased expression of receptors with mutations of residues in the network. Many of the GnRH receptor mutations associated with congenital hypogonadotropic hypogonadism, including the Glu2.53(90) Lys mutation, involve amino acids that constitute the conserved network. Half of the ~250 intramolecular interactions in GPCRs differ between inactive and active structures. Conformation-specific interhelical contacts depend on amino acids changing partners during activation. Conserved inactive conformation-specific contacts prevent receptor activation by stabilizing proximity of TM helices 3 and 6 and a closed G protein-binding site. Mutations of GnRH receptor residues involved in these interactions, such as Arg3.50(139) of the DRY/S motif or Tyr7.53(323) of the N/DPxxY motif, increase or decrease receptor expression and efficiency of receptor coupling to G protein signaling, consistent with the native residues stabilizing the inactive GnRH receptor structure. Active conformation-specific interhelical contacts stabilize an open G protein-binding site. Progress in defining the GnRH-binding site has recently slowed, with evidence that Tyr6.58(290) contacts Tyr5 of GnRH, whereas other residues affect recognition of Trp3 and Gly10NH2. The surprisingly consistent observations that GnRH receptor mutations that disrupt GnRH binding have less effect on "conformationally constrained" GnRH peptides may now be explained by crystal structures of agonist-bound peptide receptors. Analysis of GPCR structures provides insight into GnRH receptor function.
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Affiliation(s)
- Colleen A. Flanagan
- Faculty of Health Sciences, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- *Correspondence: Colleen A. Flanagan,
| | - Ashmeetha Manilall
- Faculty of Health Sciences, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
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22
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Ulloa-Aguirre A, Lira-Albarrán S. Clinical Applications of Gonadotropins in the Male. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 143:121-174. [PMID: 27697201 DOI: 10.1016/bs.pmbts.2016.08.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The pituitary gonadotropins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) play a pivotal role in reproduction. The synthesis and secretion of gonadotropins are regulated by complex interactions among several endocrine, paracrine, and autocrine factors of diverse chemical structure. In men, LH regulates the synthesis of androgens by the Leydig cells, whereas FSH promotes Sertoli cell function and thereby influences spermatogenesis. Gonadotropins are complex molecules composed of two subunits, the α- and β-subunit, that are noncovalently associated. Gonadotropins are decorated with glycans that regulate several functions of the protein including folding, heterodimerization, stability, transport, conformational maturation, efficiency of heterodimer secretion, metabolic fate, interaction with their cognate receptor, and selective activation of signaling pathways. A number of congenital and acquired abnormalities lead to gonadotropin deficiency and hypogonadotropic hypogonadism, a condition amenable to treatment with exogenous gonadotropins. Several natural and recombinant preparations of gonadotropins are currently available for therapeutic purposes. The difference between natural and the currently available recombinant preparations (which are massively produced in Chinese hamster ovary cells for commercial purposes) mainly lies in the abundance of some of the carbohydrates that conform the complex glycans attached to the protein core. Whereas administration of exogenous gonadotropins in patients with isolated congenital hypogonadotropic hypogonadism is a well recognized therapeutic approach, their role in treating men with normogonadotropic idiopathic infertility is still controversial. This chapter concentrates on the main structural and functional features of the gonadotropin hormones and how basic concepts have been translated into the clinical arena to guide therapy for gonadotropin deficit in males.
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Affiliation(s)
- A Ulloa-Aguirre
- Research Support Network, Universidad Nacional Autónoma de México (UNAM)-National Institutes of Health, Mexico City, Mexico.
| | - S Lira-Albarrán
- Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
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Choi SG, Wang Q, Jia J, Chikina M, Pincas H, Dolios G, Sasaki K, Wang R, Minamino N, Salton SRJ, Sealfon SC. Characterization of Gonadotrope Secretoproteome Identifies Neurosecretory Protein VGF-derived Peptide Suppression of Follicle-stimulating Hormone Gene Expression. J Biol Chem 2016; 291:21322-21334. [PMID: 27466366 DOI: 10.1074/jbc.m116.740365] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Indexed: 01/21/2023] Open
Abstract
Reproductive function is controlled by the pulsatile release of hypothalamic gonadotropin-releasing hormone (GnRH), which regulates the expression of the gonadotropins luteinizing hormone and FSH in pituitary gonadotropes. Paradoxically, Fshb gene expression is maximally induced at lower frequency GnRH pulses, which provide a very low average concentration of GnRH stimulation. We studied the role of secreted factors in modulating gonadotropin gene expression. Inhibition of secretion specifically disrupted gonadotropin subunit gene regulation but left early gene induction intact. We characterized the gonadotrope secretoproteome and global mRNA expression at baseline and after Gαs knockdown, which has been found to increase Fshb gene expression (1). We identified 1077 secreted proteins or peptides, 19 of which showed mRNA regulation by GnRH or/and Gαs knockdown. Among several novel secreted factors implicated in Fshb gene regulation, we focused on the neurosecretory protein VGF. Vgf mRNA, whose gene has been implicated in fertility (2), exhibited high induction by GnRH and depended on Gαs In contrast with Fshb induction, Vgf induction occurred preferentially at high GnRH pulse frequency. We hypothesized that a VGF-derived peptide might regulate Fshb gene induction. siRNA knockdown or extracellular immunoneutralization of VGF augmented Fshb mRNA induction by GnRH. GnRH stimulated the secretion of the VGF-derived peptide NERP1. NERP1 caused a concentration-dependent decrease in Fshb gene induction. These findings implicate a VGF-derived peptide in selective regulation of the Fshb gene. Our results support the concept that signaling specificity from the cell membrane GnRH receptor to the nuclear Fshb gene involves integration of intracellular signaling and exosignaling regulatory motifs.
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Affiliation(s)
| | - Qian Wang
- From the Departments of Neurology and
| | | | | | | | | | - Kazuki Sasaki
- Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center Research Institute, Osaka 565-8565, Japan
| | | | - Naoto Minamino
- Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center Research Institute, Osaka 565-8565, Japan
| | - Stephen R J Salton
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029 and
| | - Stuart C Sealfon
- From the Departments of Neurology and Center for Advanced Research on Diagnostic Assays, and
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Nederpelt I, Vergroesen R, IJzerman A, Heitman L. Persistent GnRH receptor activation in pituitary αT3-1 cells analyzed with a label-free technology. Biosens Bioelectron 2016; 79:721-7. [DOI: 10.1016/j.bios.2015.12.066] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 12/10/2015] [Accepted: 12/20/2015] [Indexed: 12/21/2022]
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Gajewska A, Zielinska-Gorska M, Wolinska-Witort E, Siawrys G, Baran M, Kotarba G, Biernacka K. Intracellular mechanisms involved in copper-gonadotropin-releasing hormone (Cu-GnRH) complex-induced cAMP/PKA signaling in female rat anterior pituitary cells in vitro. Brain Res Bull 2015; 120:75-82. [PMID: 26551063 DOI: 10.1016/j.brainresbull.2015.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/31/2015] [Accepted: 11/03/2015] [Indexed: 01/24/2023]
Abstract
The copper-gonadotropin-releasing hormone molecule (Cu-GnRH) is a GnRH analog, which preserves its amino acid sequence, but which contains a Cu(2+) ion stably bound to the nitrogen atoms including that of the imidazole ring of Histidine(2). A previous report indicated that Cu-GnRH was able to activate cAMP/PKA signaling in anterior pituitary cells in vitro, but raised the question of which intracellular mechanism(s) mediated the Cu-GnRH-induced cAMP synthesis in gonadotropes. To investigate this mechanism, in the present study, female rat anterior pituitary cells in vitro were pretreated with 0.1 μM antide, a GnRH antagonist; 0.1 μM cetrorelix, a GnRH receptor antagonist; 0.1 μM PACAP6-38, a PAC-1 receptor antagonist; 2 μM GF109203X, a protein kinase C inhibitor; 50 mM PMA, a protein kinase C activator; the protein kinase A inhibitors H89 (30 μM) and KT5720 (60 nM); factors affecting intracellular calcium activity: 2.5 mM EGTA; 2 μM thapsigargin; 5 μM A23187, a Ca(2+) ionophore; or 10 μg/ml cycloheximide, a protein synthesis inhibitor. After one of the above pretreatments, cells were incubated in the presence of 0.1 μM Cu-GnRH for 0.5, 1, and 3 h. Radioimmunoassay analysis of cAMP confirmed the functional link between Cu-GnRH stimulation and cAMP/PKA signal transduction in rat anterior pituitary cells, demonstrating increased intracellular cAMP, which was reduced in the presence of specific PKA inhibitors. The stimulatory effect of Cu-GnRH on cAMP production was partly dependent on GnRH receptor activation. In addition, an indirect and Ca(2+)-dependent mechanism might be involved in intracellular adenylate cyclase stimulation. Neither activation of protein kinase C nor new protein synthesis was involved in the Cu-GnRH-induced increase of cAMP in the rat anterior pituitary primary cultures. Presented data indicate that conformational changes of GnRH molecule resulting from cooper ion coordination affect specific pharmacological properties of Cu-GnRH molecule including specific pattern of intracellular activity induced by complex in anterior pituitary cells in vitro.
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Affiliation(s)
- Alina Gajewska
- Department of Neuroendocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jablonna n. Warsaw, Poland.
| | - Marlena Zielinska-Gorska
- Department of Neuroendocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jablonna n. Warsaw, Poland
| | - Ewa Wolinska-Witort
- Neuroendocrinology Department, Medical Centre for Postgraduate Education, Marymoncka 99/103 st., 01-813 Warsaw, Poland
| | - Gabriela Siawrys
- Department of Animal Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A st. 10-719 Olsztyn, Poland
| | - Marta Baran
- Department of Neuroendocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jablonna n. Warsaw, Poland
| | - Grzegorz Kotarba
- Department of Neuroendocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jablonna n. Warsaw, Poland
| | - Katarzyna Biernacka
- Department of Neuroendocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jablonna n. Warsaw, Poland
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26
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Dang AK, Murtazina DA, Magee C, Navratil AM, Clay CM, Amberg GC. GnRH evokes localized subplasmalemmal calcium signaling in gonadotropes. Mol Endocrinol 2015; 28:2049-59. [PMID: 25333516 DOI: 10.1210/me.2014-1208] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The binding of GnRH to its receptor initiates signaling cascades in gonadotropes, which result in enhanced LH and FSH biosynthesis and secretion. This process is necessary for follicular maturation and ovulation. Calcium influx activates MAPKs, which lead to increased transcription of LH and FSH genes. Previous research suggests that two MAPK signaling pathways, ERK and jun-N-terminal kinase, are activated by either calcium influx through L-type calcium channels or by global calcium signals originating from intracellular stores, respectively. Here we continued this investigation to further elucidate molecular mechanisms transducing GnRH receptor stimulation to ERK activation. Although it is known that GnRH activation of ERK requires calcium influx through L-type calcium channels, direct evidence supporting an underlying local calcium signaling mechanism was lacking. Here we used a combination of electrophysiology and total internal reflection fluorescence microscopy to visualize discrete sites of calcium influx (calcium sparklets) in gonadotrope-derived αT3-1 cells in real time. GnRH increased localized calcium influx and promoted ERK activation. The L-type calcium channel agonist FPL 64176 enhanced calcium sparklets and ERK activation in a manner indistinguishable from GnRH. Conversely, the L-type calcium channel antagonist nicardipine inhibited not only localized calcium sparklets but also ERK activation in response to GnRH. GnRH-dependent stimulation of L-type calcium channels was found to require protein kinase C and a dynamic actin cytoskeleton. Taken together, we provide the first direct evidence for localized L-type calcium channel signaling in αT3-1 cells and demonstrate the utility of our approach for investigating signaling mechanisms and cellular organization in gonadotropes.
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Affiliation(s)
- An K Dang
- Department of Biomedical Sciences (A.K.D., D.A.M., C.M., C.M.C., G.C.A.), Colorado State University, Ft Collins, Colorado 80523; and Department of Zoology and Physiology (A.M.N.), University of Wyoming, Laramie, Wyoming 82071
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27
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Park S, Han JM, Cheon J, Hwang JI, Seong JY. Apoptotic death of prostate cancer cells by a gonadotropin-releasing hormone-II antagonist. PLoS One 2014; 9:e99723. [PMID: 24926857 PMCID: PMC4057422 DOI: 10.1371/journal.pone.0099723] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 05/18/2014] [Indexed: 01/11/2023] Open
Abstract
Gonadotropin-releasing hormone-I (GnRH-I) has attracted strong attention as a hormonal therapeutic tool, particularly for androgen-dependent prostate cancer patients. However, the androgen-independency of the cancer in advanced stages has spurred researchers to look for new medical treatments. In previous reports, we developed the GnRH-II antagonist Trp-1 to inhibit proliferation and stimulate the autophagic death of various prostate cancer cells, including androgen-independent cells. We further screened many GnRH-II antagonists to identify molecules with higher efficiency. Here, we investigated the effect of SN09-2 on the growth of PC3 prostate cancer cells. SN09-2 reduced the growth of prostate cancer cells but had no effect on cells derived from other tissues. Compared with Trp-1, SN09-2 conspicuously inhibited prostate cancer cell growth, even at low concentrations. SN09-2-induced PC3 cell growth inhibition was associated with decreased membrane potential in mitochondria where the antagonist was accumulated, and increased mitochondrial and cytosolic reactive oxygen species. SN09-2 induced lactate dehydrogenase release into the media and annexin V-staining on the PC3 cell surface, suggesting that the antagonist stimulated prostate cancer cell death by activating apoptotic signaling pathways. Furthermore, cytochrome c release from mitochondria to the cytosol and caspase-3 activation occurred in a concentration- and time-dependent manner. SN09-2 also inhibited the growth of PC3 cells xenotransplanted into nude mice. These results demonstrate that SN09-2 directly induces mitochondrial dysfunction and the consequent ROS generation, leading to not only growth inhibition but also apoptosis of prostate cancer cells.
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Affiliation(s)
- Sumi Park
- Graduate School of Medicine, Korea University, Seoul, Republic of Korea
| | - Ji Man Han
- Graduate School of Medicine, Korea University, Seoul, Republic of Korea
| | - Jun Cheon
- Department of Urology, School of Medicine, Korea University, Seoul, Republic of Korea
| | - Jong-Ik Hwang
- Graduate School of Medicine, Korea University, Seoul, Republic of Korea
- * E-mail: (J-IH); (JYS)
| | - Jae Young Seong
- Graduate School of Medicine, Korea University, Seoul, Republic of Korea
- * E-mail: (J-IH); (JYS)
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28
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Choi SG, Wang Q, Jia J, Pincas H, Turgeon JL, Sealfon SC. Growth differentiation factor 9 (GDF9) forms an incoherent feed-forward loop modulating follicle-stimulating hormone β-subunit (FSHβ) gene expression. J Biol Chem 2014; 289:16164-75. [PMID: 24778184 DOI: 10.1074/jbc.m113.537696] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) is secreted in brief pulses from the hypothalamus and regulates follicle-stimulating hormone β-subunit (FSHβ) gene expression in pituitary gonadotropes in a frequency-sensitive manner. The mechanisms underlying its preferential and paradoxical induction of FSHβ by low frequency GnRH pulses are incompletely understood. Here, we identify growth differentiation factor 9 (GDF9) as a GnRH-suppressed autocrine inducer of FSHβ gene expression. GDF9 gene transcription and expression were preferentially decreased by high frequency GnRH pulses. GnRH regulation of GDF9 was concentration-dependent and involved ERK and PKA. GDF9 knockdown or immunoneutralization reduced FSHβ mRNA expression. Conversely, exogenous GDF9 induced FSHβ expression in immortalized gonadotropes and in mouse primary pituitary cells. GDF9 exposure increased FSH secretion in rat primary pituitary cells. GDF9 induced Smad2/3 phosphorylation, which was impeded by ALK5 knockdown and by activin receptor-like kinase (ALK) receptor inhibitor SB-505124, which also suppressed FSHβ expression. Smad2/3 knockdown indicated that FSHβ induction by GDF9 involved Smad2 and Smad3. FSHβ mRNA induction by GDF9 and GnRH was synergistic. We hypothesized that GDF9 contributes to a regulatory loop that tunes the GnRH frequency-response characteristics of the FSHβ gene. To test this, we determined the effects of GDF9 knockdown on FSHβ induction at different GnRH pulse frequencies using a parallel perifusion system. Reduction of GDF9 shifted the characteristic pattern of GnRH pulse frequency sensitivity. These results identify GDF9 as contributing to an incoherent feed-forward loop, comprising both intracellular and secreted components, that regulates FSHβ expression in response to activation of cell surface GnRH receptors.
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Affiliation(s)
- Soon Gang Choi
- From the Center for Translational Systems Biology and Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York 10029 and
| | - Qian Wang
- From the Center for Translational Systems Biology and Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York 10029 and
| | - Jingjing Jia
- From the Center for Translational Systems Biology and Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York 10029 and
| | - Hanna Pincas
- From the Center for Translational Systems Biology and Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York 10029 and
| | - Judith L Turgeon
- the Division of Endocrinology, Department of Internal Medicine, School of Medicine, University of California, Davis, California 95616
| | - Stuart C Sealfon
- From the Center for Translational Systems Biology and Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York 10029 and
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29
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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: 112] [Impact Index Per Article: 11.2] [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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30
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Pincas H, Choi SG, Wang Q, Jia J, Turgeon JL, Sealfon SC. Outside the box signaling: secreted factors modulate GnRH receptor-mediated gonadotropin regulation. Mol Cell Endocrinol 2014; 385:56-61. [PMID: 23994024 PMCID: PMC3964483 DOI: 10.1016/j.mce.2013.08.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/13/2013] [Accepted: 08/19/2013] [Indexed: 12/24/2022]
Abstract
Control of gene expression following activation of membrane receptors results from the regulation of intracellular signaling pathways and transcription factors. Accordingly, research to elucidate the regulatory control circuits and cellular data processing mechanisms focuses on intracellular mechanisms. While autocrine and paracrine signaling are acknowledged in endocrinology, secreted factors are not typically recognized as fundamental components of the pathways connecting cell surface receptors to gene control in the nucleus. Studies of the gonadotrope suggest that extracellular regulatory loops may play a central role in the regulation of gonadotropin gene expression by gonadotropin-releasing hormone (GnRH) receptor activation. We review emerging evidence for this phenomenon, which we refer to as exosignaling, in gonadotropin gene control and in other receptor-mediated signaling systems. We propose that basic signaling circuit modules controlling gene expression can be seamlessly distributed across intracellular and exosignaling components that together orchestrate the precise physiological control of gene expression.
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Affiliation(s)
- Hanna Pincas
- Department of Neurology, Center for Translational Systems Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| | - Soon Gang Choi
- Department of Neurology, Center for Translational Systems Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| | - Qian Wang
- Department of Neurology, Center for Translational Systems Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| | - Jingjing Jia
- Department of Neurology, Center for Translational Systems Biology, Icahn School of Medicine at Mount Sinai, 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.
| | - Stuart C Sealfon
- Department of Neurology, Center for Translational Systems Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
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31
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Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Spedding M, Peters JA, Harmar AJ. The Concise Guide to PHARMACOLOGY 2013/14: G protein-coupled receptors. Br J Pharmacol 2013; 170:1459-581. [PMID: 24517644 PMCID: PMC3892287 DOI: 10.1111/bph.12445] [Citation(s) in RCA: 505] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. G protein-coupled receptors are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.
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Affiliation(s)
- Stephen PH Alexander
- School of Life Sciences, University of Nottingham Medical SchoolNottingham, NG7 2UH, UK
| | - Helen E Benson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Elena Faccenda
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Adam J Pawson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Joanna L Sharman
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | | | - John A Peters
- Neuroscience Division, Medical Education Institute, Ninewells Hospital and Medical School, University of DundeeDundee, DD1 9SY, UK
| | - Anthony J Harmar
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
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32
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Perrett RM, McArdle CA. Molecular mechanisms of gonadotropin-releasing hormone signaling: integrating cyclic nucleotides into the network. Front Endocrinol (Lausanne) 2013; 4:180. [PMID: 24312080 PMCID: PMC3834291 DOI: 10.3389/fendo.2013.00180] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 11/06/2013] [Indexed: 01/21/2023] Open
Abstract
Gonadotropin-releasing hormone (GnRH) is the primary regulator of mammalian reproductive function in both males and females. It acts via G-protein coupled receptors on gonadotropes to stimulate synthesis and secretion of the gonadotropin hormones luteinizing hormone and follicle-stimulating hormone. These receptors couple primarily via G-proteins of the Gq/ll family, driving activation of phospholipases C and mediating GnRH effects on gonadotropin synthesis and secretion. There is also good evidence that GnRH causes activation of other heterotrimeric G-proteins (Gs and Gi) with consequent effects on cyclic AMP production, as well as for effects on the soluble and particulate guanylyl cyclases that generate cGMP. Here we provide an overview of these pathways. We emphasize mechanisms underpinning pulsatile hormone signaling and the possible interplay of GnRH and autocrine or paracrine regulatory mechanisms in control of cyclic nucleotide signaling.
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Affiliation(s)
- Rebecca M. Perrett
- Laboratories for Integrative Neuroscience and Endocrinology, School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Craig A. McArdle
- Laboratories for Integrative Neuroscience and Endocrinology, School of Clinical Sciences, University of Bristol, Bristol, UK
- *Correspondence: Craig A. McArdle, Laboratories for Integrative Neuroscience and Endocrinology, School of Clinical Sciences, University of Bristol, 1 Whitson Street, Bristol BS1 3NY, UK e-mail:
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Mita M. Release of Relaxin-Like Gonad-Stimulating Substance from Starfish Radial Nerves by lonomycin. Zoolog Sci 2013; 30:602-6. [DOI: 10.2108/zsj.30.602] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Hall JA, Decatur WA, Daukss DM, Hayes MK, Marquis TJ, Morin SJ, Kelleher TF, Sower SA. Expression of three GnRH receptors in specific tissues in male and female sea lampreys Petromyzon marinus at three distinct life stages. Front Neurosci 2013; 7:88. [PMID: 23754972 PMCID: PMC3664763 DOI: 10.3389/fnins.2013.00088] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 05/10/2013] [Indexed: 11/17/2022] Open
Abstract
Two recently cloned gonadotropin-releasing hormone (GnRH) receptors (lamprey GnRH-R-2 and lamprey GnRH-R-3) along with lamprey (l) GnRH-R-1 were shown to share similar structural features and amino acid motifs common to other vertebrate receptors. Here we report on our findings of RNA expression of these three GnRH receptors in the three major life stages (larval, parasitic, and adult phases) of the sea lamprey, Petromyzon marinus, a basal vertebrate. For each stage, we examined the expression of messenger RNA encoding the receptors in the brain, pituitary, gonad, heart, muscle, liver, eye, intestine, kidney, skin, thyroid, gill, and endostyle by RT-PCR. In adult lampreys, the spatial expression of the three receptors in the brain and pituitary was investigated by in situ hybridization. In general, the receptors were more widely expressed in adult tissues as compared to parasitic-phase tissues and least widely expressed in the larval tissues. There were noted differences in male and female lampreys in the adult and parasitic phases for all three receptors. The data showed the presence of all three receptor transcripts in brain tissues for adult and parasitic phases and all three receptor transcripts were expressed in the adult pituitaries, but not in the parasitic pituitaries. However, in the larval phase, only lGnRH-R-1 was expressed in the larval brain and pituitary. In situ hybridization revealed that lGnRH-R-2 and -3 were expressed in the pineal tissue of adult female lampreys while lGnRH-R-1 was expressed in the pineal in adult male lampreys, all restricted to the pineal pellucida. In summary, these data provide an initial comparative analysis of expression of three lamprey GnRH receptors suggesting differential regulation within males and females at three different life/reproductive stages.
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Affiliation(s)
- Jeffrey A Hall
- Department of Molecular, Cellular and Biomedical Sciences, Center for Molecular and Comparative Endocrinology, University of New Hampshire Durham, NH, USA
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Abstract
G protein-coupled receptors (GPCRs) are the largest class of integral membrane protein receptors in the human genome. We examined here the reports whether the GnRH receptor (GnRHR) interacts with a single or multiple types of G proteins. It seems that the GnRHR, as other GPCRs, alternates between various conformations and is stabilized by its ligands, other modulators and intracellular partners in selective conformations culminating in coupling with a single type or multiple G proteins in a cell- and context-specific manner.
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Affiliation(s)
- Zvi Naor
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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Joseph NT, Aquilina-Beck A, MacDonald C, Decatur WA, Hall JA, Kavanaugh SI, Sower SA. Molecular cloning and pharmacological characterization of two novel GnRH receptors in the lamprey (Petromyzon marinus). Endocrinology 2012; 153:3345-56. [PMID: 22569788 PMCID: PMC3380312 DOI: 10.1210/en.2012-1217] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This paper reports the identification, expression, binding kinetics, and functional studies of two novel type III lamprey GnRH receptors (lGnRH-R-2 and lGnRH-R-3) in the sea lamprey, a basal vertebrate. These novel GnRH receptors share the structural features and amino acid motifs common to other known gnathostome GnRH receptors. The ligand specificity and activation of intracellular signaling studies showed ligands lGnRH-II and -III induced an inositol phosphate (IP) response at lGnRH-R-2 and lGnRH-R-3, whereas the ligand lGnRH-I did not stimulate an IP response. lGnRH-II was a more potent activator of lGnRH-R-3 than lGnRH-III. Stimulation of lGnRH-R-2 and lGnRH-R-3 testing all three lGnRH ligands did not elicit a cAMP response. lGnRH-R-2 has a higher binding affinity in response to lGnRH-III than lGnRH-II, whereas lGnRH-R-3 has a higher binding affinity in response to lGnRH-II than IGnRH-III. lGnRH-R-2 precursor transcript was detected in a wide variety of tissues including the pituitary whereas lGnRH-R-3 precursor transcript was not as widely expressed and primarily expressed in the brain and eye of male and female lampreys. From our phylogenetic analysis, we propose that lGnRH-R-1 evolved from a common ancestor of all vertebrate GnRH receptors and lGnRH-R-2 and lGnRH-R-3 likely occurred due to a gene duplication within the lamprey lineage. In summary, we propose from our findings of receptor subtypes in the sea lamprey that the evolutionary recruitment of specific pituitary GnRH receptor subtypes for particular physiological functions seen in later evolved vertebrates was an ancestral character that first arose in a basal vertebrate.
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Affiliation(s)
- Nerine T Joseph
- Center for Molecular and Comparative Endocrinology and Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire 03824, USA
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Son YL, Ubuka T, Millar RP, Kanasaki H, Tsutsui K. Gonadotropin-inhibitory hormone inhibits GnRH-induced gonadotropin subunit gene transcriptions by inhibiting AC/cAMP/PKA-dependent ERK pathway in LβT2 cells. Endocrinology 2012; 153:2332-43. [PMID: 22374973 DOI: 10.1210/en.2011-1904] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A neuropeptide that directly inhibits gonadotropin secretion from the pituitary was discovered in quail and named gonadotropin-inhibitory hormone (GnIH). The presence and functional roles of GnIH orthologs, RF-amide-related peptides (RFRP), that possess a common C-terminal LPXRF-amide (X = L or Q) motif have also been demonstrated in mammals. GnIH orthologs inhibit gonadotropin synthesis and release by acting on pituitary gonadotropes and GnRH neurons in the hypothalamus via its receptor (GnIH receptor). It is becoming increasingly clear that GnIH is an important hypothalamic neuropeptide controlling reproduction, but the detailed signaling pathway mediating the inhibitory effect of GnIH on target cells is still unknown. In the present study, we investigated the pathway of GnIH cell signaling and its possible interaction with GnRH signaling using a mouse gonadotrope cell line, LβT2. First, we demonstrated the expression of GnIH receptor mRNA in LβT2 cells by RT-PCR. We then examined the inhibitory effects of mouse GnIH orthologs [mouse RFRP (mRFRP)] on GnRH-induced cell signaling events. We showed that mRFRP effectively inhibited GnRH-induced cAMP signaling by using a cAMP-sensitive reporter system and measuring cAMP levels, indicating that mRFRP function as an inhibitor of adenylate cyclase. We further showed that mRFRP inhibited GnRH-stimulated ERK phosphorylation, and this effect was mediated by the inhibition of the protein kinase A pathway. Finally, we demonstrated that mRFRP inhibited GnRH-stimulated gonadotropin subunit gene transcriptions and also LH release. Taken together, the results indicate that mRFRP function as GnIH to inhibit GnRH-induced gonadotropin subunit gene transcriptions by inhibiting adenylate cyclase/cAMP/protein kinase A-dependent ERK activation in LβT2 cells.
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Affiliation(s)
- You Lee Son
- Laboratory of Integrative Brain Sciences, Department of Biology, Waseda University, Center for Medical Life Science of Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
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Cohen-Tannoudji J, Avet C, Garrel G, Counis R, Simon V. Decoding high Gonadotropin-releasing hormone pulsatility: a role for GnRH receptor coupling to the cAMP pathway? Front Endocrinol (Lausanne) 2012; 3:107. [PMID: 22969749 PMCID: PMC3431540 DOI: 10.3389/fendo.2012.00107] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 08/15/2012] [Indexed: 01/06/2023] Open
Abstract
The gonadotropin-releasing hormone (GnRH) pulsatile pattern is critical for appropriate regulation of gonadotrope activity but only little is known about the signaling mechanisms by which gonadotrope cells decode such pulsatile pattern. Here, we review recent lines of evidence showing that the GnRH receptor (GnRH-R) activates the cyclic AMP (cAMP) pathway in gonadotrope cells, thus ending a long-lasting controversy. Interestingly, coupling of GnRH-R to the cAMP pathway as well as induction of nitric oxide synthase 1 (NOS1) or follistatin through this signaling pathway take place preferentially under high GnRH pulsatility. The preovulatory surge of GnRH in vivo is indeed associated with an important increase of pituitary cAMP and NOS1 expression levels, both being markedly inhibited by treatment with a GnRH antagonist. Altogether, this suggests that due to its atypical structure and desensitization properties, the GnRH-R may continue to signal through the cAMP pathway under conditions inducing desensitization for most other receptors. Such a mechanism may contribute to decode high GnRH pulsatile pattern and enable gonadotrope cell plasticity during the estrus cycle.
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Affiliation(s)
- Joëlle Cohen-Tannoudji
- *Correspondence: Joëlle Cohen-Tannoudji, Equipe Physiologie de l’Axe Gonadotrope, Unité de Biologie Fonctionnelle et Adaptative, CNRS-EAC 4413, Sorbonne Paris Cité, Université Paris Diderot-Paris 7, Case courrier 7007, 4 rue Marie-Andrée Lagroua- Weill-Hallé, 75013 Paris, France. e-mail:
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Sower SA, Decatur WA, Joseph NT, Freamat M. Evolution of vertebrate GnRH receptors from the perspective of a Basal vertebrate. Front Endocrinol (Lausanne) 2012. [PMID: 23181055 PMCID: PMC3500703 DOI: 10.3389/fendo.2012.00140] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
This minireview provides the current status on gonadotropin-releasing hormone receptors (GnRH-R) in vertebrates, from the perspective of a basal vertebrate, the sea lamprey, and provides an evolutionary scheme based on the recent advance of whole genome sequencing. In addition, we provide a perspective on the functional divergence and evolution of the receptors. In this review we use the phylogenetic classification of vertebrate GnRH receptors that groups them into three clusters: type I (mammalian and non-mammalian), type II, and type III GnRH receptors. New findings show that the sea lamprey has two type III-like GnRH receptors and an ancestral type GnRH receptor that is more closely related to the type II-like receptors. These two novel GnRH receptors along with lGnRH-R-1 share similar structural features and amino acid motifs common to other known gnathostome type II/III receptors. Recent data analyses of the lamprey genome provide strong evidence that two whole rounds of genome duplication (2R) occurred prior to the gnathostome-agnathan split. Based on our current knowledge, it is proposed that lGnRH-R-1 evolved from an ancestor of the type II receptor following a vertebrate-shared genome duplication and that the two type III receptors resulted from a duplication within lamprey of a gene derived from a lineage shared by many vertebrates.
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Affiliation(s)
- Stacia A. Sower
- Department of Molecular, Cellular and Biomedical Sciences, Center for Molecular and Comparative Endocrinology, University of New HampshireDurham, NH, USA
- *Correspondence: Stacia A. Sower, Department of Molecular, Cellular and Biomedical Sciences, Center for Molecular and Comparative Endocrinology, University of New Hampshire, 46 College Road, Durham, NH 03824-3544, USA. e-mail:
| | - Wayne A. Decatur
- Department of Molecular, Cellular and Biomedical Sciences, Center for Molecular and Comparative Endocrinology, University of New HampshireDurham, NH, USA
| | - Nerine T. Joseph
- Department of Molecular, Cellular and Biomedical Sciences, Center for Molecular and Comparative Endocrinology, University of New HampshireDurham, NH, USA
| | - Mihael Freamat
- Department of Molecular, Cellular and Biomedical Sciences, Center for Molecular and Comparative Endocrinology, University of New HampshireDurham, NH, USA
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Biochemistry, molecular biology and cell biology of gonadotropin-releasing hormone antagonists. Curr Opin Obstet Gynecol 2011; 23:238-44. [DOI: 10.1097/gco.0b013e328348a3ce] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Russo A, Castiglione F, Salonia A, Benigni F, Rigatti P, Montorsi F, Andersson KE, Hedlund P. Effects of the gonadotropin-releasing hormone antagonist ganirelix on normal micturition and prostaglandin E(2)-induced detrusor overactivity in conscious female rats. Eur Urol 2010; 59:868-74. [PMID: 21196074 DOI: 10.1016/j.eururo.2010.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Accepted: 12/10/2010] [Indexed: 01/15/2023]
Abstract
BACKGROUND Gonadotropin-releasing hormone (GnRH) antagonists have been reported to have beneficial effects on lower urinary tract symptoms in patients with benign prostatic hyperplasia. OBJECTIVE Our aim was to investigate the effects of ganirelix, a GnRH receptor antagonist, on bladder function and detrusor overactivity (DO) in female rats. DESIGN, SETTING, AND PARTICIPANTS Female Sprague-Dawley rats received 2 wk of daily systemic (0.1 mg/kg) or acute intravesical administration (IVES; 0.14 mg/l or 1.4 mg/l) ganirelix or vehicle (controls). MEASUREMENTS Assessments were obtained using cystometry in awake rats, organ bath studies, enzyme-linked immunosorbent assay, and western blot (WB). RESULTS AND LIMITATIONS Luteinising hormone levels were lower in rats treated systemically with ganirelix than in controls. No differences were observed in body or bladder weights. Micturition interval (MI), micturition volume (MV), residual volume, and bladder capacity (BC) were similar in both groups at baseline. No differences in urodynamic pressure parameters were observed between groups at baseline. Intravesical prostaglandin E(2) reduced MI, MV, and BC, and it increased basal pressure (BP), threshold pressure (TP), flow pressure (FP), and maximum pressure (MP) in all rats. MI, MV, and BC were reduced by 43%±4%, 50%±4%, and 43%±4% (controls) versus 22%±3%, 23%±3%, and 21%±3% (ganirelix-treated rats; p<0.001). TP and FP increased by 38%±8% and 30%±4% (controls) versus 16%±7% and 16%±5% (ganirelix; p<0.05). The maximal force of contractions for carbachol was larger in detrusor from ganirelix-treated rats (231% vs 177% of 60 mM K+-induced contractions). At 0.14 mg/l, but not 0.14 mg/l, IVES ganirelix increased MI, MV, and BC and decreased BP, TP, FP, and MP. In vitro, ganirelix had no effect on detrusor function. The gonadotropin-releasing hormone receptor was expressed (by WB) in the bladder mucosa. CONCLUSIONS Systemic treatment with ganirelix counteracted experimental DO in female rats. Because bladder preparations from these rats exhibited larger contractions to carbachol and because intravesical ganirelix affected both micturition intervals and urodynamic pressure profiles, a peripheral site of action of ganirelix in the urinary bladder cannot be excluded.
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Affiliation(s)
- Andrea Russo
- Urological Research Institute, San Raffaele University, Milan, Italy
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Re M, Pampillo M, Savard M, Dubuc C, McArdle CA, Millar RP, Conn PM, Gobeil F, Bhattacharya M, Babwah AV. The human gonadotropin releasing hormone type I receptor is a functional intracellular GPCR expressed on the nuclear membrane. PLoS One 2010; 5:e11489. [PMID: 20628612 PMCID: PMC2900216 DOI: 10.1371/journal.pone.0011489] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 06/11/2010] [Indexed: 12/02/2022] Open
Abstract
The mammalian type I gonadotropin releasing hormone receptor (GnRH-R) is a structurally unique G protein-coupled receptor (GPCR) that lacks cytoplasmic tail sequences and displays inefficient plasma membrane expression (PME). Compared to its murine counterparts, the primate type I receptor is inefficiently folded and retained in the endoplasmic reticulum (ER) leading to a further reduction in PME. The decrease in PME and concomitant increase in intracellular localization of the mammalian GnRH-RI led us to characterize the spatial distribution of the human and mouse GnRH receptors in two human cell lines, HEK 293 and HTR-8/SVneo. In both human cell lines we found the receptors were expressed in the cytoplasm and were associated with the ER and nuclear membrane. A molecular analysis of the receptor protein sequence led us to identify a putative monopartite nuclear localization sequence (NLS) in the first intracellular loop of GnRH-RI. Surprisingly, however, neither the deletion of the NLS nor the addition of the Xenopus GnRH-R cytoplasmic tail sequences to the human receptor altered its spatial distribution. Finally, we demonstrate that GnRH treatment of nuclei isolated from HEK 293 cells expressing exogenous GnRH-RI triggers a significant increase in the acetylation and phosphorylation of histone H3, thereby revealing that the nuclear-localized receptor is functional. Based on our findings, we conclude that the mammalian GnRH-RI is an intracellular GPCR that is expressed on the nuclear membrane. This major and novel discovery causes us to reassess the signaling potential of this physiologically and clinically important receptor.
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Affiliation(s)
- Michelle Re
- The Children's Health Research Institute, London, Canada
- Lawson Health Research Institute, London, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Canada
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada
| | - Macarena Pampillo
- The Children's Health Research Institute, London, Canada
- Lawson Health Research Institute, London, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Canada
| | - Martin Savard
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Canada
| | - Céléna Dubuc
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Canada
| | - Craig A. McArdle
- Laboratories for Integrated Neuroscience and Endocrinology, Department of Clinical Sciences at South Bristol, University of Bristol, Bristol, United Kingdom
| | - Robert P. Millar
- MRC Human Reproductive Sciences Unit, The Queen's Medical Research Institute, Edinburgh, United Kingdom
| | - P. Michael Conn
- Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States of America
| | - Fernand Gobeil
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Canada
| | - Moshmi Bhattacharya
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada
| | - Andy V. Babwah
- The Children's Health Research Institute, London, Canada
- Lawson Health Research Institute, London, Canada
- Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Canada
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada
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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: 151] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [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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Shimizu M, Bédécarrats GY. Activation of the chicken gonadotropin-inhibitory hormone receptor reduces gonadotropin releasing hormone receptor signaling. Gen Comp Endocrinol 2010; 167:331-7. [PMID: 20350548 DOI: 10.1016/j.ygcen.2010.03.029] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 03/15/2010] [Accepted: 03/25/2010] [Indexed: 10/19/2022]
Abstract
Gonadotropin-inhibitory hormone (GnIH) is a hypothalamic peptide from the RFamide peptide family that has been identified in multiple avian species. Although GnIH has clearly been shown to reduce LH release from the anterior pituitary gland, its mechanism of action remains to be determined. The overall objectives of this study were (1) to characterize the GnIH receptor (GnIH-R) signaling pathway, (2) to evaluate potential interactions with gonadotropin releasing hormone type III receptor (GnRH-R-III) signaling, and (3) to determine the molecular mechanisms by which GnIH and GnRH regulate pituitary gonadotrope function during a reproductive cycle in the chicken. Using real-time PCR, we showed that in the chicken pituitary gland, GnIH-R mRNA levels fluctuate in an opposite manner to GnRH-R-III, with higher and lower levels observed during inactive and active reproductive stages, respectively. We demonstrated that the chicken GnIH-R signals by inhibiting adenylyl cyclase cAMP production, most likely by coupling to G(alphai). We also showed that this inhibition is sufficient to significantly reduce GnRH-induced cAMP responsive element (CRE) activation in a dose-dependent manner, and that the ratio of GnRH/GnIH receptors is a significant factor. We propose that in avian species, sexual maturation is characterized by a change in GnIH/GnRH receptor ratio, resulting in a switch in pituitary sensitivity from inhibitory (involving GnIH) to stimulatory (involving GnRH). In turn, decreasing GnIH-R signaling, combined with increasing GnRH-R-III signaling, results in significant increases in CRE activation, possibly initiating gonadotropin synthesis.
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Affiliation(s)
- Mamiko Shimizu
- Department of Animal and Poultry Science, University of Guelph, Guelph, Ont., Canada N1H 6H8
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Kosugi T, Sower SA. A role of Histidine151 in the lamprey gonadotropin-releasing hormone receptor-1 (lGnRHR-1): Functional insight of diverse amino acid residues in the position of Tyr of the DRY motif in GnRHR from an ancestral type II receptor. Gen Comp Endocrinol 2010; 166:498-503. [PMID: 20005226 PMCID: PMC2856804 DOI: 10.1016/j.ygcen.2009.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Accepted: 12/04/2009] [Indexed: 10/20/2022]
Abstract
The highly conserved DRY motif located at the end of the third transmembrane of G-protein-coupled receptors has been described as a key motif for several aspects of GPCR functions. However, in the case of the vertebrate gonadotropin-releasing hormone receptor (GnRHR), the amino acid in the third position in the DRY motif is variable. In the lamprey, a most basal vertebrate, the third amino acid of the "DRY" in lamprey (lGnRHR-1) is His, while it is most often His/Gln in the type II GnRHR. To investigate the functional significance of the substitution of DRY to DRH in the GnRHR-1, second messenger signaling, ligand binding and internalization of the wild-type and mutant lGnRH receptors were characterized with site-directed mutagenesis. Treatment of the DRE(151) and DRS(151) mutant receptors with lamprey GnRH-I significantly reduced inositol phosphate compared to wild-type (DRH(151)) and DRY(151) receptors. The LogIC(50) of wild-type receptor (-9.554+/-0.049) was similar to the LogIC(50) of DRE(151), DRS(151) and DRX(151) mutants, yet these same mutants were shown to significantly reduce cell-surface expression. However, the DRY(151) mutant compared to the wild-type receptor increased cell-surface expression, suggesting that the reduction of IP production was due to the level of the cell-surface expression of the mutant receptors. The rate of internalization of DRX(151) (35.60%) was reduced compared to wild-type and other mutant receptors. These results suggest that His(151) of the lamprey GnRH receptor-1 may play a critical role in the retention of a certain level of cell-surface expression for subsequent cellular second messenger events.
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Affiliation(s)
| | - Stacia A. Sower
- Corresponding author: Dr. Stacia A. Sower. Center for Molecular and Comparative Endocrinology, University of New Hampshire, 46 College Road Durham NH 3824 USA.
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Tsutsumi R, Mistry D, Webster NJG. Signaling responses to pulsatile gonadotropin-releasing hormone in LbetaT2 gonadotrope cells. J Biol Chem 2010; 285:20262-72. [PMID: 20406815 DOI: 10.1074/jbc.m110.132662] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The hypothalamic neuropeptide gonadotropin-releasing hormone (GnRH) is secreted in a pulsatile fashion by hypothalamic neurons, and alterations in pulse frequency and amplitude differentially regulate gonadotropin synthesis and release. In this study, we investigated the kinetics of G(s) and G(q) signaling in response to continuous or pulsatile GnRH using fluorescence resonance energy transfer reporters in live mouse LbetaT2 gonadotrope cells. cAMP and protein kinase A-dependent reporters showed a rapid but transient increase in fluorescence resonance energy transfer signal with increasing doses of constant GnRH, and in contrast diacylglycerol (DAG) and calcium reporters showed a rapid and sustained signal. Multiple pulses of GnRH caused multiple pulses of cAMP and protein kinase A activation without desensitization, but the DAG and calcium reporters were rapidly desensitized resulting in inhibition of calcium and DAG responses. At the transcriptional level, both a cAMP-dependent cAMP-response element reporter and a DAG/calcium-dependent AP-1 reporter showed a pulse frequency-dependent increase in luciferase activity. However, constant GnRH stimulation gave very little cAMP-response element activation but very strong AP-1 activation. Based on these data, we propose that both the GnRH-R-G(s) and G(q) pathways are responsive to pulses of GnRH, but only the G(q) pathway is responsive to constant GnRH. Furthermore, the G(q) pathway is subject to desensitization with multiple GnRH pulses, but the G(s) pathway is not.
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Affiliation(s)
- Rie Tsutsumi
- Medical Research Service, Veterans Affairs San Diego Healthcare System, San Diego, California 92161, USA
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Krsmanovic LZ, Hu L, Leung PK, Feng H, Catt KJ. Pulsatile GnRH secretion: roles of G protein-coupled receptors, second messengers and ion channels. Mol Cell Endocrinol 2010; 314:158-63. [PMID: 19486924 PMCID: PMC2815227 DOI: 10.1016/j.mce.2009.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 05/21/2009] [Accepted: 05/24/2009] [Indexed: 12/31/2022]
Abstract
The pulsatile secretion of GnRH from normal and immortalized hypothalamic GnRH neurons is highly calcium-dependent and is stimulated by cAMP. It is also influenced by agonist activation of the endogenous GnRH receptor (GnRH-R), which couples to multiple G proteins. This autocrine mechanism could serve as a timer to determine the frequency of pulsatile GnRH release by regulating Ca(2+)- and cAMP-dependent signaling and GnRH neuronal firing. The firing of individual and/or bursts of action potentials (APs) in spontaneously active GnRH neurons is followed by afterhyperpolarization (AHP) that lasts from several milliseconds to several seconds. GnRH-induced activation of GnRH neurons causes a significant increase in medium AHP that is partially sensitive to apamin. GnRH-induced modulation of Ca(2+) influx and the consequent changes in AHP current suggest that the GnRH receptors expressed in hypothalamic GnRH neurons are important modulators of their neuronal excitability. The coexistence of multiple regulatory mechanisms could provide a high degree of redundancy in the maintenance of this crucial component of the reproductive process. It is also conceivable that this multifactorial system could reflect the gradation from simple to more complex neuroendocrine control systems for regulating hypothalamo-pituitary function and gonadal activity during the evolution of the GnRH pulse generator.
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Affiliation(s)
- Lazar Z Krsmanovic
- Section on Hormonal Regulation, PDEGEN, NICHD, NIH, Bethesda, MD 20892, USA.
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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: 37] [Impact Index Per Article: 2.5] [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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