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Axiak CJ, Pleven A, Attard R, Borg Carbott F, Ebejer JP, Brincat I, Cassar K, Gruppetta M, Vassallo J, Bezzina Wettinger S, Farrugia R. High Population Frequency of GNRHR p.Q106R in Malta: An Evaluation of Fertility and Hormone Profiles in Heterozygotes. J Endocr Soc 2024; 8:bvad172. [PMID: 38196663 PMCID: PMC10775685 DOI: 10.1210/jendso/bvad172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Indexed: 01/11/2024] Open
Abstract
Context The gonadotropin-releasing hormone receptor variant GNRHR p.Q106R (rs104893836) in homozygosity, compound heterozygosity, or single heterozygosity is often reported as the causative variant in idiopathic hypogonadotropic hypogonadism (IHH) patients with GnRH deficiency. Genotyping of a Maltese newborn cord-blood collection yielded a minor allele frequency (MAF) 10 times higher (MAF = 0.029; n = 493) than that of the global population (MAF = 0.003). Objective To determine whether GNRHR p.Q106R in heterozygosity influences profiles of endogenous hormones belonging to the hypothalamic-pituitary axis and the onset of puberty and fertility in adult men (n = 739) and women (n = 239). Design Setting and Participants Analysis of questionnaire data relating to puberty and fertility, genotyping of the GNRHR p.Q106R variant, and hormone profiling of a highly phenotyped Maltese adult cohort from the Maltese Acute Myocardial Infarction Study. Main Outcome and Results Out of 978 adults, 43 GNRHR p.Q106R heterozygotes (26 men and 17 women) were identified. Hormone levels and fertility for all heterozygotes are within normal parameters except for TSH, which was lower in men 50 years or older. Conclusion Hormone data and baseline fertility characteristics of GNRHR p.Q106R heterozygotes are comparable to those of homozygous wild-type individuals who have no reproductive problems. The heterozygous genotype alone does not impair the levels of investigated gonadotropins and sex steroid hormones or affect fertility. GNRHR p.Q106R heterozygotes who exhibit IHH characteristics must have at least another variant, probably in a different IHH gene, that drives pathogenicity. We also conclude that GNRHR p.Q106R is likely a founder variant due to its overrepresentation and prevalence in the island population of Malta.
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Affiliation(s)
- Clayton John Axiak
- Department of Applied Biomedical Science, Faculty of Health Sciences, University of Malta, Msida, MSD 2080, Malta
| | - Adrian Pleven
- Department of Applied Biomedical Science, Faculty of Health Sciences, University of Malta, Msida, MSD 2080, Malta
- Clinical Chemistry Section, Department of Pathology, Mater Dei Hospital, Msida, MSD 2080, Malta
| | - Ritienne Attard
- Department of Applied Biomedical Science, Faculty of Health Sciences, University of Malta, Msida, MSD 2080, Malta
| | - Francesca Borg Carbott
- Department of Applied Biomedical Science, Faculty of Health Sciences, University of Malta, Msida, MSD 2080, Malta
| | - Jean-Paul Ebejer
- Centre for Molecular Medicine and Biobanking, University of Malta, Msida, MSD 2080, Malta
| | - Ian Brincat
- Clinical Chemistry Section, Department of Pathology, Mater Dei Hospital, Msida, MSD 2080, Malta
| | - Karen Cassar
- Department of Medicine, Faculty of Medicine and Surgery, University of Malta, Msida, MSD 2080, Malta
| | - Mark Gruppetta
- Department of Medicine, Faculty of Medicine and Surgery, University of Malta, Msida, MSD 2080, Malta
- Division of Endocrinology and Diabetes, Department of Medicine, Mater Dei Hospital, Msida, MSD 2080, Malta
| | - Josanne Vassallo
- Centre for Molecular Medicine and Biobanking, University of Malta, Msida, MSD 2080, Malta
- Department of Medicine, Faculty of Medicine and Surgery, University of Malta, Msida, MSD 2080, Malta
- Division of Endocrinology and Diabetes, Department of Medicine, Mater Dei Hospital, Msida, MSD 2080, Malta
| | - Stephanie Bezzina Wettinger
- Department of Applied Biomedical Science, Faculty of Health Sciences, University of Malta, Msida, MSD 2080, Malta
- Centre for Molecular Medicine and Biobanking, University of Malta, Msida, MSD 2080, Malta
| | - Rosienne Farrugia
- Department of Applied Biomedical Science, Faculty of Health Sciences, University of Malta, Msida, MSD 2080, Malta
- Centre for Molecular Medicine and Biobanking, University of Malta, Msida, MSD 2080, Malta
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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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Tsai MC, Hsu CH, Chu SK, Roy-Gagnon MH, Lin SH. Genome-wide association study of age at menarche in the Taiwan Biobank suggests NOL4 as a novel associated gene. J Hum Genet 2023; 68:339-345. [PMID: 36710296 DOI: 10.1038/s10038-023-01124-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 01/15/2023] [Accepted: 01/17/2023] [Indexed: 01/31/2023]
Abstract
Sexual maturation is a complex physiological process that involves multiple variables, such as genetic and environmental factors. Among females, age at menarche (AM) is a critical milestone for sexual maturation. This study aimed to identify genetic markers of AM using nationwide population cohort data in Taiwan. Females with self-reported AM between 10 and 16 years (N = 39,827) were eligible for the final analysis. To identify genetic signals related to AM, we conducted a genome-wide association study using a linear regression model and split-half meta-analysis method to verify our findings. The Functional Mapping and Annotation web-based platform was used for positional mapping and gene-based and gene-set analyses. The meta-analysis identified four significant loci, i.e., LIN28B (pooled P = 1.39 × 10-21), NOL4 (pooled P = 8.94 × 10-9), GPR45 (pooled P = 4.19 × 10-11), and LOC105373831 (pooled P = 4.37 × 10-8), that were associated with AM. MAGMA gene-based analysis revealed that LIN28B (P = 1.13 × 10-8), NOL4 (P = 2.27 × 10-7), RXRG (P = 4.34 × 10-7), ETV5 (P = 1.75 × 10-6), and HACE1 (P = 1.82 × 10-6) were significantly associated with AM, while the gene-set analysis identified a significantly enriched pathway involving mTOR signaling complex (FDR corrected P = 1.28 × 10-2). The results replicated evidence for several genetic markers associated with AM in the Taiwanese female population. Our analysis identified a novel locus (rs7239368) in NOL4 associated with AM (β = 0.051 ± 0.009 years, pooled P = 8.94 × 10-9), whereas additional research is needed to validate its molecular role in sexual maturation.
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Affiliation(s)
- Meng-Che Tsai
- Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Genomic Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Medical Humanities and Social Medicine, Collage of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chih-Hui Hsu
- Biostatistics Consulting Center, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Shih-Kai Chu
- Institute of Statistical Science, Academia Sinica, Taipei, Taiwan.,Clinical Research Center, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | | | - Sheng-Hsiang Lin
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan. .,Biostatistics Consulting Center, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan. .,Department of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
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Makretskaya NA, Gerasimova MV, Vasilyev EV, Zubkova NA, Kalinchenko NY, Kolodkina AA, Petrov VM, Pogoda TV, Panova AV, Frolova EB, Poliakov AV, Tiulpakov AN. [Clinical and molecular genetic features of cases of isolated hypogonadotropic hypogonadism, associated with defects in GNRHR genes]. ACTA ACUST UNITED AC 2021; 67:62-67. [PMID: 34297503 DOI: 10.14341/probl12746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 04/25/2021] [Accepted: 05/01/2021] [Indexed: 11/06/2022]
Abstract
Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder characterised by lack of pubertal development and infertility, due to deficient production, secretion or action of gonadotropin-releasing hormone (GnRH). Clinically, there are variants of CHH with hypo-/anosmia (Kalman syndrome) and normosmic hypogonadotropic hypogonadism. Given a growing list of gene mutations accounting for CHH, the application of next generation sequencing (NGS) comprises an excellent molecular diagnostic approach because it enables the simultaneous evaluation of many genes. Biallelic mutations in GNRHR gene lead to the development of hypogonadotropic hypogonadism with normosmia. In this paper, we describe 16 patients with proven GnRH resistance and estimate the frequency of pathogenic variants in the GNRHR gene in the Russian population.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - E B Frolova
- National Medical Research Center for Children's
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5
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Wang L, Lin W, Li X, Zhang L, Wang K, Cui X, Tang S, Fang G, Tan Y, Wang X, Chen C, Yang C, Tang H. A case report of congenital idiopathic hypogonadotropic hypogonadism caused by novel mutation of GNRHR gene. Medicine (Baltimore) 2021; 100:e24007. [PMID: 33592857 PMCID: PMC7870162 DOI: 10.1097/md.0000000000024007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 12/03/2020] [Indexed: 01/05/2023] Open
Abstract
RATIONALE This study aimed to investigate the genetic mutation characteristics of congenital idiopathic hypogonadotropic hypogonadism (IHH) through the clinical features and genetic analysis of 2 patients with IHH in 1 pedigree. PATIENT CONCERNS A 23-year-old girl presented with primary amenorrhea, sparse pubic hair, lack of breast development, and delayed sexual development. DIAGNOSES Combined with the clinical characteristics, auxiliary examinations, and molecular genetic analysis, the patient was diagnosed as IHH. INTERVENTIONS Whole exome and Sanger sequencing were performed to validate the mutation in family members. OUTCOMES A novel homozygous missense mutation c.521A > G (p.Q174R) in the GNRHR gene was identified in the 2 affected sisters. Familial segregation showed that the homozygous variant was inherited from their parents respectively and the eldest sister was the carrier without correlative symptom. LESSONS We reported a novel GNRHR mutation in a pedigree with congenital idiopathic hypogonadotropic hypogonadism. Glutamine at amino acid position 174 was highly conserved among various species. The molecular structure of GNRHR protein showed that p.Q174R mutation brought in a new stable hydrogen bond between position 174 and 215, may impede conformational mobility of the TMD4 and TMD5. It suggests that the missense mutation c.521A > G related to congenital idiopathic hypogonadotropic hypogonadism was probably a causative factor for both sisters. Through high-throughput sequencing and experimental verification, we had basically determined the patient's pathogenic mutation and inheritance, which could better guide doctors for treatment.
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Affiliation(s)
- Liping Wang
- Peking University Shenzhen Hospital
- Shenzhen Key Laboratory of Gynecological Diagnostic Technology Research
| | | | - Xiaohong Li
- Peking University Shenzhen Hospital
- Shenzhen Key Laboratory of Gynecological Diagnostic Technology Research
| | | | - Kai Wang
- CheerLand Precision Biomed Co., Ltd
| | | | | | - Guangguang Fang
- Shenzhen Dapeng New District Maternity & Child Health Hospital Department of Gynecology
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Yan Tan
- Shenzhen Dapeng New District Maternity & Child Health Hospital Department of Gynecology
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Xuelai Wang
- Li Ka Shing Faculty of Medicine, School of Biomedical Science, the University of Hong Kong, Hong Kong
| | | | | | - Huiru Tang
- Peking University Shenzhen Hospital
- Shenzhen Key Laboratory of Gynecological Diagnostic Technology Research
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6
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Cangiano B, Duminuco P, Vezzoli V, Guizzardi F, Chiodini I, Corona G, Maggi M, Persani L, Bonomi M. Evidence for a Common Genetic Origin of Classic and Milder Adult-Onset Forms of Isolated Hypogonadotropic Hypogonadism. J Clin Med 2019; 8:jcm8010126. [PMID: 30669598 PMCID: PMC6352096 DOI: 10.3390/jcm8010126] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 01/05/2023] Open
Abstract
Multiple metabolic and inflammatory mechanisms are considered the determinants of acquired functional isolated hypogonadotropic hypogonadism (IHH) in males, whereas classic IHH is a rare congenital condition with a strong genetic background. Since we recently uncovered a frequent familiarity for classic IHH among patients with mild adult-onset hypogonadism (AO-IHH), here we performed a genetic characterization by next generation sequencing of 160 males with classic or “functional” forms. The prevalence of rare variants in 28 candidate genes was significantly higher than in controls in all IHH patients, independently of the age of IHH onset, degree of hypogonadism or presence of obesity. In fact, it did not differ among patients with classic or milder forms of IHH, however particular genes appear to be more specifically associated with one or the other category of IHH. ROC curves showed that Total Testosterone <6.05 nmol/L and an age of onset <41 years are sensitive cutoffs to identify patients with significantly higher chances of harboring rare IHH gene variants. In conclusion, rare IHH genes variants can frequently predispose to AO-IHH with acquired mild hormonal deficiencies. The identification of a genetic predisposition can improve the familial and individual management of AO-IHH and explain the heritability of congenital IHH.
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Affiliation(s)
- Biagio Cangiano
- Department of Clinical Sciences and Community Health, University of Milan, 20100 Milan, Italy.
- IRCCS Istituto Auxologico Italiano, Division of Endocrine and Metabolic Diseases & Lab. of Endocrine and Metabolic Research, 20149 Milan, Italy.
| | - Paolo Duminuco
- IRCCS Istituto Auxologico Italiano, Division of Endocrine and Metabolic Diseases & Lab. of Endocrine and Metabolic Research, 20149 Milan, Italy.
| | - Valeria Vezzoli
- IRCCS Istituto Auxologico Italiano, Division of Endocrine and Metabolic Diseases & Lab. of Endocrine and Metabolic Research, 20149 Milan, Italy.
| | - Fabiana Guizzardi
- IRCCS Istituto Auxologico Italiano, Division of Endocrine and Metabolic Diseases & Lab. of Endocrine and Metabolic Research, 20149 Milan, Italy.
| | - Iacopo Chiodini
- Department of Clinical Sciences and Community Health, University of Milan, 20100 Milan, Italy.
- IRCCS Istituto Auxologico Italiano, Division of Endocrine and Metabolic Diseases & Lab. of Endocrine and Metabolic Research, 20149 Milan, Italy.
| | - Giovanni Corona
- Endocrinology Unit, Medical Department, Azienda USL, Maggiore-Bellaria Hospital, 40133 Bologna, Italy.
| | - Mario Maggi
- Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", University of Florence, 50139 Florence, Italy.
| | - Luca Persani
- Department of Clinical Sciences and Community Health, University of Milan, 20100 Milan, Italy.
- IRCCS Istituto Auxologico Italiano, Division of Endocrine and Metabolic Diseases & Lab. of Endocrine and Metabolic Research, 20149 Milan, Italy.
| | - Marco Bonomi
- Department of Clinical Sciences and Community Health, University of Milan, 20100 Milan, Italy.
- IRCCS Istituto Auxologico Italiano, Division of Endocrine and Metabolic Diseases & Lab. of Endocrine and Metabolic Research, 20149 Milan, Italy.
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Min L, Nie M, Zhang A, Wen J, Noel SD, Lee V, Carroll RS, Kaiser UB. Computational Analysis of Missense Variants of G Protein-Coupled Receptors Involved in the Neuroendocrine Regulation of Reproduction. Neuroendocrinology 2016; 103:230-9. [PMID: 26088945 PMCID: PMC4684493 DOI: 10.1159/000435884] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/10/2015] [Indexed: 01/13/2023]
Abstract
INTRODUCTION Many missense variants in G protein-coupled receptors (GPCRs) involved in the neuroendocrine regulation of reproduction have been identified by phenotype-driven or large-scale exome sequencing. Computational functional prediction analysis is commonly performed to evaluate their impact on receptor function. METHODS To assess the performance and outcome of functional prediction analyses for these GPCRs, we performed a statistical analysis of the prediction performance of SIFT and PolyPhen-2 for variants with documented biological function as well as variants retrieved from Ensembl. We obtained missense variants with documented biological function testing from patients with reproductive disorders from a comprehensive literature search. Missense variants from individuals with known reproductive disorders were retrieved from the Human Gene Mutation Database. Missense variants from the general population were retrieved from the Ensembl genome database. RESULTS The accuracies of SIFT and PolyPhen-2 were 83 and 85%, respectively. The performance of both prediction tools was greater in predicting loss-of-function variants (SIFT: 92%; PolyPhen-2: 95%) than in predicting variants that did not affect function (SIFT: 54%; PolyPhen-2: 57%). Concordance between SIFT and PolyPhen-2 did not improve accuracy. Surprisingly, approximately half of the variants retrieved from Ensembl were predicted as loss-of-function variants by SIFT (47%) and PolyPhen-2 (54%). CONCLUSION Our findings provide new guidance for interpreting the results and limitations of computational functional prediction analyses for GPCRs and will help to determine which variants require biological function testing. In addition, our findings raise important questions regarding the link between genotype and phenotype in the general population.
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Affiliation(s)
- Le Min
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA, 02115 USA
- To whom correspondence and reprint requests should be addressed: Le Min, M.D., Ph.D., Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, 221 Longwood Avenue, Boston, Massachusetts 02115.
| | - Min Nie
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA, 02115 USA
| | - Anna Zhang
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA, 02115 USA
| | - Junping Wen
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA, 02115 USA
| | - Sekoni D. Noel
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA, 02115 USA
| | - Vivian Lee
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA, 02115 USA
| | - Rona S. Carroll
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA, 02115 USA
| | - Ursula B. Kaiser
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA, 02115 USA
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8
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Guimiot F, Chevrier L, Dreux S, Chevenne D, Caraty A, Delezoide AL, de Roux N. Negative fetal FSH/LH regulation in late pregnancy is associated with declined kisspeptin/KISS1R expression in the tuberal hypothalamus. J Clin Endocrinol Metab 2012; 97:E2221-9. [PMID: 23015653 DOI: 10.1210/jc.2012-2078] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
OBJECTIVE Kisspeptins were recently identified as hypothalamic neuropeptides that control GnRH release at pubertal onset and in adults via the activation of KISS-1 receptor (KISS1R). Here, we have tested whether the fetal activation of the gonadotropic axis is related to the hypothalamic expression of kisspeptins and KISS1R. DESIGN AND METHODS LH and FSH levels were measured in fetal blood from the 15th week of gestation (WG) to birth. Immunohistochemistry was performed on the hypothalamus and pituitary at different developmental stages. RESULTS Immunostaining for kisspeptins and KISS1R appeared for both proteins in the hypothalamus as early as 15 WG and subsequently increased until 30-31 WG. In the meantime, serum LH and FSH levels decreased from postmenopausal levels in females or adult levels in males to very low levels. At full term, kisspeptin and KISS1R staining was still observed in the paraventricular, supraoptic, and ventromedial hypothalamic nuclei but not in the arcuate nucleus or median eminence. Hypothalamic GnRH staining was observed at 15 WG and did not vary after the first trimester. In an arhinencephalic fetus of 23 WG, very few GnRH neurons were observed in the hypothalamus, but serum FSH and LH levels were postmenopausal. CONCLUSION Serum LH and FSH levels are independent from GnRH and kisspeptins at midgestation, and then GnRH progressively controls LH and FSH release. A shift from kisspeptin-independent to kisspeptin-dependent GnRH-induced LH and FSH release seems to occur after 30-31 WG. In addition to their function in adults, kisspeptins are also the master regulators of the gonadotropic axis activation in the fetus.
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Affiliation(s)
- Fabien Guimiot
- Institut National de la Santé et de la Recherche Médicale, Unité 676, F-75739 Paris, France
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9
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Gürbüz F, Kotan LD, Mengen E, Şıklar Z, Berberoğlu M, Dökmetaş S, Kılıçlı MF, Güven A, Kirel B, Saka N, Poyrazoğlu Ş, Cesur Y, Doğan M, Özen S, Özbek MN, Demirbilek H, Kekil MB, Temiz F, Önenli Mungan N, Yüksel B, Topaloğlu AK. Distribution of gene mutations associated with familial normosmic idiopathic hypogonadotropic hypogonadism. J Clin Res Pediatr Endocrinol 2012; 4:121-6. [PMID: 22766261 PMCID: PMC3459159 DOI: 10.4274/jcrpe.725] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE Normosmic idiopathic hypogonadotropic hypogonadism (nIHH) is characterized by failure of initiation or maintenance of puberty due to insufficient gonadotropin release, which is not associated with anosmia/hyposmia. The objective of this study was to determine the distribution of causative mutations in a hereditary form of nIHH. METHODS In this prospective collaborative study, 22 families with more than one affected individual (i.e. multiplex families) with nIHH were recruited and screened for genes known or suspected to be strong candidates for nIHH. RESULTS Mutations were identified in five genes (GNRHR, TACR3, TAC3, KISS1R, and KISS1) in 77% of families with autosomal recessively inherited nIHH. GNRHR and TACR3 mutations were the most common two causative mutations occurring with about equal frequency. CONCLUSIONS Mutations in these five genes account for about three quarters of the causative mutations in nIHH families with more than one affected individual. This frequency is significantly greater than the previously reported rates in all inclusive (familial plus sporadic) cohorts. GNRHR and TACR3 should be the first two genes to be screened for diagnostic purposes. Identification of causative mutations in the remaining families will shed light on the regulation of puberty.
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Affiliation(s)
- Fatih Gürbüz
- Çukurova University Faculty of Medicine, Department of Pediatric Endocrinology, Adana, Turkey
| | - L. Damla Kotan
- Çukurova University Institute of Sciences, Department of Biotechnology, Adana, Turkey
| | - Eda Mengen
- Çukurova University Faculty of Medicine, Department of Pediatric Endocrinology, Adana, Turkey
| | - Zeynep Şıklar
- Ankara University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey
| | - Merih Berberoğlu
- Ankara University Faculty of Medicine, Department of Pediatric Endocrinology, Ankara, Turkey
| | - Sebila Dökmetaş
- Cumhuriyet University Faculty of Medicine, Department of Endocrinology, Sivas, Turkey
| | - Mehmet Fatih Kılıçlı
- Cumhuriyet University Faculty of Medicine, Department of Endocrinology, Sivas, Turkey
| | - Ayla Güven
- Göztepe Educational and Research Hospital, Department of Pediatric Endocrinology, İstanbul, Turkey
| | - Birgül Kirel
- Osmangazi University Faculty of Medicine, Department of Pediatric Endocrinology, Eskişehir, Turkey
| | - Nurçin Saka
- İstanbul University Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey
| | - Şükran Poyrazoğlu
- İstanbul University Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey
| | - Yaşar Cesur
- Yüzüncü Yıl University Faculty of Medicine, Department of Pediatric Endocrinology, Van, Turkey
| | - Murat Doğan
- Yüzüncü Yıl University Faculty of Medicine, Department of Pediatric Endocrinology, Van, Turkey
| | - Samim Özen
- Mersin Children’s Hospital, Department of Pediatric Endocrinology, Mersin, Turkey
| | - Mehmet Nuri Özbek
- Diyarbakır Children’s Hospital, Department of Pediatric Endocrinology, Diyarbakır, Turkey
| | - Hüseyin Demirbilek
- Diyarbakır Children’s Hospital, Department of Pediatric Endocrinology, Diyarbakır, Turkey
| | - M. Burcu Kekil
- Çukurova University Institute of Sciences, Department of Biotechnology, Adana, Turkey
| | - Fatih Temiz
- Çukurova University Faculty of Medicine, Department of Pediatric Endocrinology, Adana, Turkey
| | - Neslihan Önenli Mungan
- Çukurova University Faculty of Medicine, Department of Pediatric Endocrinology, Adana, Turkey
| | - Bilgin Yüksel
- Çukurova University Faculty of Medicine, Department of Pediatric Endocrinology, Adana, Turkey
| | - Ali Kemal Topaloğlu
- Çukurova University Faculty of Medicine, Department of Pediatric Endocrinology, Adana, Turkey
,
Çukurova University Institute of Sciences, Department of Biotechnology, Adana, Turkey
,* Address for Correspondence :growth Phone : +90 322 338 70 83 E-mail :
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10
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Tello JA, Newton CL, Bouligand J, Guiochon-Mantel A, Millar RP, Young J. Congenital hypogonadotropic hypogonadism due to GnRH receptor mutations in three brothers reveal sites affecting conformation and coupling. PLoS One 2012; 7:e38456. [PMID: 22679506 PMCID: PMC3367945 DOI: 10.1371/journal.pone.0038456] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 05/06/2012] [Indexed: 11/21/2022] Open
Abstract
Congenital hypogonadotropic hypogonadism (CHH) is characterized by low gonadotropins and failure to progress normally through puberty. Mutations in the gene encoding the GnRH receptor (GNRHR1) result in CHH when present as compound heterozygous or homozygous inactivating mutations. This study identifies and characterizes the properties of two novel GNRHR1 mutations in a family in which three brothers display normosmic CHH while their sister was unaffected. Molecular analysis in the proband and the affected brothers revealed two novel non-synonymous missense GNRHR1 mutations, present in a compound heterozygous state, whereas their unaffected parents possessed only one inactivating mutation, demonstrating the autosomal recessive transmission in this kindred and excluding X-linked inheritance equivocally suggested by the initial pedigree analysis. The first mutation at c.845 C>G introduces an Arg substitution for the conserved Pro 282 in transmembrane domain (TMD) 6. The Pro282Arg mutant is unable to bind radiolabeled GnRH analogue. As this conserved residue is important in receptor conformation, it is likely that the mutation perturbs the binding pocket and affects trafficking to the cell surface. The second mutation at c.968 A>G introduces a Cys substitution for Tyr 323 in the functionally crucial N/DPxxY motif in TMD 7. The Tyr323Cys mutant has an increased GnRH binding affinity but reduced receptor expression at the plasma membrane and impaired G protein-coupling. Inositol phosphate accumulation assays demonstrated absent and impaired Gαq/11 signal transduction by Pro282Arg and Tyr323Cys mutants, respectively. Pretreatment with the membrane permeant GnRHR antagonist NBI-42902, which rescues cell surface expression of many GNRHR1 mutants, significantly increased the levels of radioligand binding and intracellular signaling of the Tyr323Cys mutant but not Pro282Arg. Immunocytochemistry confirmed that both mutants are present on the cell membrane albeit at low levels. Together these molecular deficiencies of the two novel GNRHR1 mutations lead to the CHH phenotype when present as a compound heterozygote.
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Affiliation(s)
- Javier A. Tello
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Claire L. Newton
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Edinburgh, United Kingdom
- University of Cape Town/Medical Research Council Receptor Biology Unit, University of Cape Town, Cape Town, South Africa
| | - Jerome Bouligand
- Univ Paris-Sud, Faculté de Médecine Paris-Sud UMR-S693, Le Kremlin Bicêtre, France
- INSERM U693, IFR93, Le Kremlin-Bicêtre, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Service de Génétique Moléculaire, Pharmacogénétique et Hormonologie, Le Kremlin Bicêtre, France
| | - Anne Guiochon-Mantel
- Univ Paris-Sud, Faculté de Médecine Paris-Sud UMR-S693, Le Kremlin Bicêtre, France
- INSERM U693, IFR93, Le Kremlin-Bicêtre, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Bicêtre, Service de Génétique Moléculaire, Pharmacogénétique et Hormonologie, Le Kremlin Bicêtre, France
| | - Robert P. Millar
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Edinburgh, United Kingdom
- University of Cape Town/Medical Research Council Receptor Biology Unit, University of Cape Town, Cape Town, South Africa
- Mammal Research Institute, University of Pretoria, Pretoria, South Africa
- * E-mail: (RPM); (JY)
| | - Jacques Young
- Univ Paris-Sud, Faculté de Médecine Paris-Sud UMR-S693, Le Kremlin Bicêtre, France
- INSERM U693, IFR93, Le Kremlin-Bicêtre, France
- Service d’Endocrinologie et des Maladies de la Reproduction, Le Kremlin Bicêtre, France
- * E-mail: (RPM); (JY)
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11
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Beate K, Joseph N, Nicolas DR, Wolfram K. Genetics of isolated hypogonadotropic hypogonadism: role of GnRH receptor and other genes. Int J Endocrinol 2012; 2012:147893. [PMID: 22229029 PMCID: PMC3249753 DOI: 10.1155/2012/147893] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 09/22/2011] [Indexed: 12/15/2022] Open
Abstract
Hypothalamic gonadotropin releasing hormone (GnRH) is a key player in normal puberty and sexual development and function. Genetic causes of isolated hypogonadotropic hypogonadism (IHH) have been identified during the recent years affecting the synthesis, secretion, or action of GnRH. Developmental defects of GnRH neurons and the olfactory bulb are associated with hyposmia, rarely associated with the clinical phenotypes of synkinesia, cleft palate, ear anomalies, or choanal atresia, and may be due to mutations of KAL1, FGFR1/FGF8, PROKR2/PROK2, or CHD7. Impaired GnRH secretion in normosmic patients with IHH may be caused by deficient hypothalamic GPR54/KISS1, TACR3/TAC3, and leptinR/leptin signalling or mutations within the GNRH1 gene itself. Normosmic IHH is predominantly caused by inactivating mutations in the pituitary GnRH receptor inducing GnRH resistance, while mutations of the β-subunits of LH or FSH are very rare. Inheritance of GnRH deficiency may be oligogenic, explaining variable phenotypes. Future research should identify additional genes involved in the complex network of normal and disturbed puberty and reproduction.
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Affiliation(s)
- Karges Beate
- Division of Endocrinology and Diabetes, University Hospital Aachen, RWTH Aachen University, 52074 Aachen, Germany
- Department of Gynecological Endocrinology and Reproductive Medicine, University Hospital Aachen, RWTH Aachen University, 52074 Aachen, Germany
- *Karges Beate:
| | - Neulen Joseph
- Department of Gynecological Endocrinology and Reproductive Medicine, University Hospital Aachen, RWTH Aachen University, 52074 Aachen, Germany
| | - de Roux Nicolas
- INSERM U676, Paris Diderot University, Robert Debré Hospital, 75019 Paris, France
| | - Karges Wolfram
- Division of Endocrinology and Diabetes, University Hospital Aachen, RWTH Aachen University, 52074 Aachen, Germany
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Chevrier L, Guimiot F, de Roux N. GnRH receptor mutations in isolated gonadotropic deficiency. Mol Cell Endocrinol 2011; 346:21-8. [PMID: 21645587 DOI: 10.1016/j.mce.2011.04.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 04/02/2011] [Indexed: 10/18/2022]
Abstract
GnRH and its receptor GnRHR are key regulators of the hypothalamo-pituitary axis. They modulate the secretion of LH and FSH gonadotropins and therefore, the development and maturation of gonads in fetal life as well as after birth. Congenital functional defect of this axis results in isolated hypogonadotropic hypogonadism (IHH). Several natural mutations causing IHH without anosmia have now been identified in GnRHR or GnRH genes. These mutations inactivate GnRHR or its ligand function and cause highly variable phenotypes, ranging from partial to complete gonadotropic deficiencies. The present review describes the published natural GnRHR mutations and tries to correlate them with the corresponding phenotypes according to the different steps of the GnRH system development.
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Affiliation(s)
- L Chevrier
- INSERM U676, Avenir Team: Genetic and Physiology of Puberty Onset, Robert Debre Hospital, 48 Boulevard Serurier, 75019 Paris, France
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13
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Abstract
In the past two decades, an increasing body of evidence has demonstrated that several G protein-coupled receptor (GPCR)-ligand pairs are critical for normal human reproductive development and function. Patients harboring genetic insults in either the receptors or their cognate ligands have presented with reproductive disorders characterized by varying degrees of GnRH deficiency. These disorders include idiopathic hypogonadotropic hypogonadism (IHH) and Kallmann Syndrome (KS). Conversely, mutations in some of these ligand-receptor pairs have been associated with accelerated reproductive maturation, manifested as central precocious puberty (CPP). To date, a series of elegant studies have characterized four GPCRs that play important roles in the neuroendocrine control of human reproductive development and function: GnRHR, KISS1R, PROKR2 and NK3R. Furthermore, these studies provide insights into the mechanisms by which mutations in these receptors give rise to reproductive disease phenotypes. This report will review mutations identified in GPCRs involved in the neuroendocrine control of the human reproductive axis with the aims of elucidating structure-function relationships of these GPCRs and identifying correlations between these structure-function relationships and the genotypic-phenotypic characterization of the patients.
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Affiliation(s)
- Sekoni D Noel
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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14
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Bouvattier C, Maione L, Bouligand J, Dodé C, Guiochon-Mantel A, Young J. Neonatal gonadotropin therapy in male congenital hypogonadotropic hypogonadism. Nat Rev Endocrinol 2011; 8:172-82. [PMID: 22009162 DOI: 10.1038/nrendo.2011.164] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Congenital hypogonadotropic hypogonadism (CHH) causes pubertal failure and infertility in both women and men due to partial or total secretory failure of the two pituitary gonadotropins lutropin (LH) and follitropin (FSH) during periods of physiological activation of the gonadotropic axis. Men and women with CHH frequently seek treatment for infertility after hypogonadism therapy. Some etiologies, such as autosomal dominant or X-linked Kallmann syndrome, raise the question of hereditary transmission, leading to increasing demands for genetic counseling and monitoring of medically assisted pregnancies. Diagnosis and treatment of newborn boys is, therefore, becoming an increasingly important issue. In male individuals with complete forms of CHH, the antenatal and neonatal gonadotropin deficit leads to formation of a micropenis and cryptorchidism, which could undermine future sexual and reproductive functions. Standard treatments, usually started after the age of puberty, often only partially correct the genital abnormalities and spermatogenesis. The aim of this Review is to examine the possible additional benefits of neonatal gonadotropin therapy in male patients with CHH. Encouraging results of neonatal therapy, together with a few reports of prepubertal treatment, support the use of this novel therapeutic strategy aimed at improving sexual and reproductive functions in adulthood.
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Affiliation(s)
- Claire Bouvattier
- Departement de Pédiatrie Endocrinienne, Hôpital Bicêtre-University Paris-Sud, 78 Rue du Général Leclerc, F-94275 Le Kremlin-Bicêtre, France
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15
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Gajdos ZK, Henderson KD, Hirschhorn JN, Palmert MR. Genetic determinants of pubertal timing in the general population. Mol Cell Endocrinol 2010; 324:21-9. [PMID: 20144687 PMCID: PMC2891370 DOI: 10.1016/j.mce.2010.01.038] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 01/26/2010] [Accepted: 01/27/2010] [Indexed: 12/21/2022]
Abstract
Puberty is an important developmental stage during which reproductive capacity is attained. The timing of puberty varies greatly among healthy individuals in the general population and is influenced by both genetic and environmental factors. Although genetic variation is known to influence the normal spectrum of pubertal timing, the specific genes involved remain largely unknown. Genetic analyses have identified a number of genes responsible for rare disorders of pubertal timing such as hypogonadotropic hypogonadism and Kallmann syndrome. Recently, the first loci with common variation reproducibly associated with population variation in the timing of puberty were identified at 6q21 in or near LIN28B and at 9q31.2. However, these two loci explain only a small fraction of the genetic contribution to population variation in pubertal timing, suggesting the need to continue to consider other loci and other types of variants. Here we provide an update of the genes implicated in disorders of puberty, discuss genes and pathways that may be involved in the timing of normal puberty, and suggest additional avenues of investigation to identify genetic regulators of puberty in the general population.
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Affiliation(s)
- Zofia K.Z. Gajdos
- Program in Genomics and Division of Endocrinology, Children’s Hospital. Boston, Massachusetts 02115; Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115; Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachusetts 02142
| | - Katherine D. Henderson
- Department of Population Sciences, Division of Cancer Etiology, City of Hope Comprehensive Cancer Center, 1500 East Duarte Road, Duarte, California 91010
| | - Joel N. Hirschhorn
- Program in Genomics and Division of Endocrinology, Children’s Hospital, Boston, Massachusetts 02115; Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115; Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachusetts 02142
| | - Mark R. Palmert
- Division of Endocrinology, The Hospital for Sick Children, Department of Paediatrics, The University of Toronto, 555 University Avenue, Toronto, Ontario, M5G 1X8, Canada, Phone: 416-813-6217, Fax: 416-813-6304
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16
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Brioude F, Bouligand J, Trabado S, Francou B, Salenave S, Kamenicky P, Brailly-Tabard S, Chanson P, Guiochon-Mantel A, Young J. Non-syndromic congenital hypogonadotropic hypogonadism: clinical presentation and genotype-phenotype relationships. Eur J Endocrinol 2010; 162:835-51. [PMID: 20207726 DOI: 10.1530/eje-10-0083] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Congenital hypogonadotropic hypogonadism (CHH) results from abnormal gonadotropin secretion, and it is characterized by impaired pubertal development. CHH is caused by defective GNRH release, or by a gonadotrope cell dysfunction in the pituitary. Identification of genetic abnormalities related to CHH has provided major insights into the pathways critical for the development, maturation, and function of the reproductive axis. Mutations in five genes have been found specifically in Kallmann's syndrome, a disorder in which CHH is related to abnormal GNRH neuron ontogenesis and is associated with anosmia or hyposmia. In combined pituitary hormone deficiency or in complex syndromic CHH in which gonadotropin deficiency is either incidental or only one aspect of a more complex endocrine disorder or a non-endocrine disorder, other mutations affecting GNRH and/or gonadotropin secretion have been reported. Often, the CHH phenotype is tightly linked to an isolated deficiency of gonadotropin secretion. These patients, who have no associated signs or hormone deficiencies independent of the deficiency in gonadotropin and sex steroids, have isolated CHH. In some familial cases, they are due to genetic alterations affecting GNRH secretion (mutations in GNRH1, GPR54/KISS1R and TAC3 and TACR3) or the GNRH sensitivity of the gonadotropic cells (GNRHR). A minority of patients with Kallmann's syndrome or a syndromic form of CHH may also appear to have isolated CHH, but close clinical, familial, and genetic studies can reorient the diagnosis, which is important for genetic counseling in the context of assisted reproductive medicine. This review focuses on published cases of isolated CHH, its clinical and endocrine features, genetic causes, and genotype-phenotype relationships.
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Affiliation(s)
- Frédéric Brioude
- Université Paris-Sud 11 and INSERM U 693, Faculté de Médecine Paris Sud, Le Kremlin Bicêtre, France
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17
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Kim HG, Pedersen-White J, Bhagavath B, Layman LC. Genotype and phenotype of patients with gonadotropin-releasing hormone receptor mutations. FRONTIERS OF HORMONE RESEARCH 2010; 39:94-110. [PMID: 20389088 DOI: 10.1159/000312696] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
Human mutations in the gonadotropin-releasing hormone receptor (GNRHR) gene cause autosomal recessive, normosmic idiopathic hypogonadotropic hypogonadism (IHH). At least 19 different mutations have been identified in this G-protein-coupled receptor, which consist mostly of missense mutations. The Gln106Arg and Arg262Gln mutations comprise nearly half of the identified alleles. Most mutations impair ligand binding and all compromise cell signaling events. Some of the mutations also adversely affect activation of gonadotropin subunit or Gnrhr gene promoters. Interestingly, a number of the mutant GnRHRs can be rescued in vitro from misfolding and degradation within the cell by the addition of a GnRHR antagonist IN3. Most affected patients have compound heterozygous GNRHR mutations that may cause either complete IHH (no evidence of puberty) or incomplete IHH (partial evidence of puberty), although some genotypes are associated with mild disease in some families and severe disease in others. GNRHR mutations also appear to cause constitutional delay of puberty, and one genotype (homozygosity for Gln106Arg) may be reversible in patients with IHH. Mutations in the human GNRHR gene have contributed greatly to the understanding of normosmic IHH, as well as the structure and function of the GnRHR.
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18
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Disrupted plasma membrane localization and loss of function reveal regions of human equilibrative nucleoside transporter 1 involved in structural integrity and activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:2326-34. [PMID: 19699178 DOI: 10.1016/j.bbamem.2009.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 07/16/2009] [Accepted: 08/12/2009] [Indexed: 01/08/2023]
Abstract
Human Equilibrative Nucleoside Transporter 1 (hENT1) is an integral membrane protein that transports nucleosides and analog drugs across cellular membranes. Very little is known about intracellular processing and localization of hENT1. Here we show that disruption of a highly conserved triplet (PWN) near the N-terminus, or the last eight C-terminal residues (two hydrophobic triplets separated by a positive arginine) result in loss of plasma membrane localization and/or transport function. To understand the role of specific residues within these regions, we studied the localization patterns of N- or C-terminal deletion and/or substitution mutants of GFP-hENT1 using confocal microscopy. Quantification of GFP-hENT1 (mutant and wildtype) protein at the plasma membrane was conducted using nitrobenzylthioinosine (NBTI) binding. Functionality of the GFP-hENT1 mutants was determined by heterologous expression in Xenopus laevis oocytes followed by measurement of uridine uptake. Mutation of the proline within the PWN motif disrupts plasma membrane localization. C-terminal mutations (primarily within the hydrophobic triplets) lead to hENT1 retention within the cell (e.g. in the ER). Some mutants still localize to the plasma membrane but show reduced transport activity. These data suggest that these two regions contribute to the structural integrity and thus correct processing and function of hENT1.
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19
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Gajdos ZK, Hirschhorn JN, Palmert MR. What controls the timing of puberty? An update on progress from genetic investigation. Curr Opin Endocrinol Diabetes Obes 2009; 16:16-24. [PMID: 19104234 DOI: 10.1097/med.0b013e328320253c] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE OF REVIEW Puberty is an important developmental stage during which reproductive capacity is attained. Genetic and environmental factors both influence the timing of puberty, which varies greatly among individuals. However, although genetic variation is known to influence the normal spectrum of pubertal timing, the specific genes involved remain unknown. RECENT FINDINGS Recent genetic analyses have identified a number of genes responsible for rare disorders of pubertal timing such as hypogonadotropic hypogonadism and Kallmann syndrome. However, although the genetic basis of population variation in the timing of puberty is an active area of investigation, no genetic loci have been reproducibly associated with pubertal timing thus far. SUMMARY This review provides an update of the genes implicated in disorders of puberty, discusses genes and pathways that may be involved in the timing of normal puberty, and suggests additional avenues of investigation to identify genetic regulators of puberty in the general population.
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Affiliation(s)
- Zofia Kz Gajdos
- Division of Endocrinology, Children's Hospital, Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
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20
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Jardón-Valadez E, Ulloa-Aguirre A, Piñeiro A. Modeling and molecular dynamics simulation of the human gonadotropin-releasing hormone receptor in a lipid bilayer. J Phys Chem B 2008; 112:10704-13. [PMID: 18680336 DOI: 10.1021/jp800544x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
In the present study, a model for the human gonadotropin-releasing hormone receptor embedded in an explicit lipid bilayer was developed. The final conformation was obtained by extensive molecular dynamics simulations of a homology model based on the bovine rhodopsin crystal structure. The analysis of the receptor structure allowed us to detect a number of specific contacts between different amino acid residues, as well as water- and lipid-mediated interactions. These interactions were stable in six additional independent 35 ns long simulations at 310 and 323 K, which used the refined model as the starting structure. All loops, particularly the extracellular loop 2 and the intracellular loop 3, exhibited high fluctuations, whereas the transmembrane helices were more static. Although other models of this receptor have been previously developed, none of them have been subjected to extensive molecular dynamics simulations, and no other three-dimensional structure is publicly available. Our results suggest that the presence of ions as well as explicit solvent and lipid molecules are critical for the structure of membrane protein models, and that molecular dynamics simulations are certainly useful for their refinement.
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Affiliation(s)
- Eduardo Jardón-Valadez
- Research Unit in Reproductive Medicine, Hospital de Ginecobstetricia Luis Castelazo Ayala, Instituto Mexicano del Seguro Social, Mexico D.F. 01090, Mexico
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Abstract
PURPOSE OF REVIEW Puberty is an important developmental and life stage that leads to sexual maturation and reproductive capability. Although the physiology of puberty is similar among individuals, the timing of puberty is quite variable and affected by environmental and genetic influences. Identification of the responsible genetic factors will greatly enhance the understanding of the key components and the modulation of the hypothalamic-pituitary-gonadal axis. RECENT FINDINGS Genetic analyses are increasingly elucidating the genetic basis of pathological abnormalities in pubertal timing, including causes of idiopathic hypogonadotropic hypogonadism and Kallmann syndrome. Ongoing studies are also investigating the genetic control of puberty in the general population, although no definitive association between genetic variants and variations in pubertal timing has been discovered so far. SUMMARY This review summarizes recent advances regarding the genetic control of pubertal timing and presents areas for future investigation.
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Kim HG, Bhagavath B, Layman LC. Clinical manifestations of impaired GnRH neuron development and function. Neurosignals 2008; 16:165-82. [PMID: 18253056 DOI: 10.1159/000111561] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) and olfactory neurons migrate together in embryologic development, and disruption of this process causes idiopathic hypogonadotropic hypogonadism (IHH) with anosmia (Kallmann syndrome (KS)). Patients with IHH/KS generally manifest irreversible pubertal delay and subsequent infertility due to deficient pituitary gonadotropins or GnRH. The molecular basis of IHH/KS includes genes that: (1) regulate GnRH and olfactory neuron migration; (2) control the synthesis or secretion of GnRH; (3) disrupt GnRH action upon pituitary gonadotropes, or (4) interfere with pituitary gonadotropin synthesis or secretion. KS patients may also have midline facial defects indicating the diverse developmental functions of genes involved. Most causative genes cause either normosmic IHH or KS except FGFR1, which may cause either phenotype. Recently, several balanced chromosomal translocations have been identified in IHH/KS patients, which could lead to the identification of new disease-producing genes. Although there are two cases reported who have digenic disease, this awaits confirmation in future larger studies. The challenge will be to determine the importance of these genes in the 10-15% of couples with normal puberty who have infertility.
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Affiliation(s)
- Hyung-Goo Kim
- Department of Obstetrics and Gynecology, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA 30912-3360, USA
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Huhtaniemi I, Alevizaki M. Mutations along the hypothalamic–pituitary–gonadal axis affecting male reproduction. Reprod Biomed Online 2007; 15:622-32. [DOI: 10.1016/s1472-6483(10)60529-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Tao YX. Inactivating mutations of G protein-coupled receptors and diseases: Structure-function insights and therapeutic implications. Pharmacol Ther 2006; 111:949-73. [PMID: 16616374 DOI: 10.1016/j.pharmthera.2006.02.008] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Accepted: 02/21/2006] [Indexed: 12/20/2022]
Abstract
Since the discovery of the first rhodopsin mutation that causes retinitis pigmentosa in 1990, significant progresses have been made in elucidating the pathophysiology of diseases caused by inactivating mutations of G protein-coupled receptors (GPCRs). This review aims to compile the compelling evidence accumulated during the past 15 years demonstrating the etiologies of more than a dozen diseases caused by inactivating GPCR mutations. A generalized classification scheme, based on the life cycle of GPCRs, is proposed. Insights gained through detailed studies of these naturally occurring mutations into the structure-function relationship of these receptors are reviewed. Therapeutic approaches directed against the different classes of mutants are being developed. Since intracellular retention emerges as the most common defect, recent progresses aimed at correcting this defect through membrane permeable pharmacological chaperones are highlighted.
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MESH Headings
- Animals
- Diabetes Insipidus, Nephrogenic/etiology
- Dwarfism/etiology
- Humans
- Hypogonadism/etiology
- Mutation
- Obesity/etiology
- Receptor, Melanocortin, Type 1/genetics
- Receptor, Melanocortin, Type 2/genetics
- Receptor, Melanocortin, Type 3/genetics
- Receptor, Parathyroid Hormone, Type 1/genetics
- Receptors, CCR5/genetics
- Receptors, Calcium-Sensing/genetics
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/physiology
- Receptors, LHRH/genetics
- Receptors, Vasopressin/genetics
- Retinitis Pigmentosa/etiology
- Rhodopsin/genetics
- Structure-Activity Relationship
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, 213 Greene Hall, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA.
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Bhagavath B, Ozata M, Ozdemir IC, Bolu E, Bick DP, Sherins RJ, Layman LC. The prevalence of gonadotropin-releasing hormone receptor mutations in a large cohort of patients with hypogonadotropic hypogonadism. Fertil Steril 2006; 84:951-7. [PMID: 16213849 DOI: 10.1016/j.fertnstert.2005.04.029] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 04/08/2005] [Accepted: 04/08/2005] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To determine the prevalence of GNRH receptor (GNRHR) gene mutations in a large cohort of patients with idiopathic hypogonadotropic hypogonadism (IHH). DESIGN Molecular analysis and genotype/phenotype correlations. SETTING University molecular reproductive endocrinology laboratory. PATIENT(S) North American and Turkish patients with IHH. INTERVENTION(S) DNA from 185 IHH patients were subjected to denaturing gradient gel electrophoresis for exons and splice junctions of the GNRHR gene. Variant fragments were sequenced. MAIN OUTCOME MEASURE(S) GNRHR mutations were characterized and compared with the phenotype. The prevalence of GNRHR mutations was also determined. RESULT(S) Three of 185 (1.6%; confidence interval [CI] 0.3%-4.7%) total IHH patients demonstrated compound heterozygous GNRHR mutations. All three were identified from a cohort of 85 normosmic patients (3.5%, CI 0.73%-7.5%), and none were demonstrated in hyposmic or anosmic IHH patients. GNRHR mutations were identified in 1 of 15 (6.7%; CI 0.2%-32.0%) families with at least two affected siblings, and in 2 of 18 (11.1%; CI 1.4%-34.7%) normosmic females. None were found in presumably autosomal dominant families. CONCLUSION(S) GNRHR mutations account for approximately 3.5% of all normosmic and 7%-11% of presumed autosomal recessive IHH, suggesting that additional genes play an important role in normal puberty. We believe this to be the largest GNRHR gene mutation analysis performed to date in a population of IHH patients.
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Affiliation(s)
- Balasubramanian Bhagavath
- Division of Reproductive Endocrinology, Infertility, and Genetics, Department of Obstetrics and Gynecology, Medical College of Georgia, Augusta, Georgia, USA
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de Roux N. [GnRH resistance and the GPR54 gene]. ACTA ACUST UNITED AC 2005; 39 Suppl 3:S37-45. [PMID: 16302709 DOI: 10.1016/s0003-4401(05)80006-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Current data make it possible to relate idiopathic hypogonadotrophic hypogonadism to mutations affecting the GnRH I-1 receptor and also to new "loss-of-function" mutations concerning another receptor, GPR54. It now seems that mutations of the pituitary GnRH receptor are not the only explanation of most cases of sporadic isolated hypogonadotrophic hypogonadism, and, on the contrary, there are certain familial forms, where no mutation has been demonstrated, suggesting the potential involvement of other genes. The role of another G protein-coupled glycoprotein membrane receptor, GRP54, already known for its involvement as a metastasis suppressor, has been demonstrated. Bioclinical studies of families affected with the disorder by pheno/genotypic correlation demonstrated that "loss-of-function" mutations affecting the GPR54 gene coding for GRP54 are the cause of hypogonadotrophic hypogonadism. GPR54 therefore appears to be involved at hypothalamic and pituitary level. It is not involved in sexual differentiation, but may modulate GnRH secretion or affect its pituitary response. Further investigations are required to determine the levels of action of this receptor which may provide a new pharmacological target in the future.
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Affiliation(s)
- Nicolas de Roux
- Service de génétique moléculaire, pharmacogénétique et hormonologie, hôpital de Bicêtre, 78, rue du Général-Leclerc, 94275 Le Kremlin-Bicêtre, France.
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Rispoli LA, Nett TM. Pituitary gonadotropin-releasing hormone (GnRH) receptor: structure, distribution and regulation of expression. Anim Reprod Sci 2005; 88:57-74. [PMID: 15993012 DOI: 10.1016/j.anireprosci.2005.05.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Reproduction in mammals is controlled by interactions between the hypothalamus, anterior pituitary and gonads. Interaction of GnRH with its cognate receptor is essential to regulating reproduction. Characterization of the structure, distribution and expression of GnRH receptors (GnRH-R) has furthered our understanding of the physiological consequences of GnRH stimulation of pituitary gonadotropes. Based on the putative topology of the amino acid sequence of the GnRH-R and point mutation studies, key elements of the GnRH-R have been identified to play a role in ligand recognition and binding, G-protein activation and internalization. Normally, reproductive function is mediated by GnRH-R expressed only on the membranes of pituitary gonadotropes. The density of GnRH-R on gonadotropes determines their ability to respond to GnRH. This density is highest just prior to ovulation and likely is important for complete expression of the pre-ovulatory surge of LH. Therefore, knowledge regarding what regulates the density of GnRH-R is essential to understanding changes in pituitary sensitivity to GnRH and ultimately, to expression of the LH surge. Regulation of GnRH-R gene expression is influenced by a multitude of factors including gonadal steroid hormones, inhibin, activin and perhaps most importantly GnRH itself.
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Affiliation(s)
- L A Rispoli
- Department of Biomedical Sciences, Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins, CO 80523, USA
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Söderhäll JA, Polymeropoulos EE, Paulini K, Günther E, Kühne R. Antagonist and agonist binding models of the human gonadotropin-releasing hormone receptor. Biochem Biophys Res Commun 2005; 333:568-82. [PMID: 15950933 DOI: 10.1016/j.bbrc.2005.05.142] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2005] [Accepted: 05/07/2005] [Indexed: 10/25/2022]
Abstract
G-protein-coupled receptors (GPCRs) constitute one of the most important classes of drug targets. Since the first high-resolution structure of a GPCR was determined by Palczewski and co-workers [K. Palczewski, T. Kumasaka, T. Hori, C.A. Behnke, H. Motoshima, B.A. Fox, I. Le Trong, D.C. Teller, T. Okada, R.E. Stenkamp, M. Yamamoto, M. Miyano, Crystal structure of rhodopsin: a G-protein-coupled receptor, Science 289 (2000) 739-745], development of in silico models of rhodopsin-like GPCRs could be rationally founded. In this work, we present a model of the human gonadotropin-releasing hormone receptor based on the rhodopsin structure. The transmembrane helices are modeled by homology, while the extra- and intra-cellular loops are modeled in such a way that experimentally determined interactions and microdomains (e.g., hydrophobic cores) are retained. We conclude that specifically tailored models, compared to more automatic approaches, have the benefit that known interactions are easily introduced early in the homology modeling. Furthermore, tailored models, although more tedious to construct, are better suited for drug lead finding and for compound optimization. To test the stability of the receptor, we performed a 1 ns molecular dynamics simulation. Moreover, we docked two agonists (native GnRH and Triptorelin, [dTrp(6)]-GnRH) and two antagonists (Cetrorelix, dNal(1)-dCpa(2)-dPal(3)-Ser(4)-Tyr(5)-dCit(6)-Leu(7)-Arg(8)-Pro(9)-dAla(10)), and the covalently constrained dicyclic decapeptide dicyclo(1,1'-5/4-10)[Ac-Glu(1)(Gly(1)')-dCpa(2)-dTrp(3)-Asp(4)-dbu(5)-dNal(6)-Leu(7)-Arg(8)-Pro(9)-dpr(10)-NH(2)] into the putative receptor binding site. The docked ligand conformations result in ligand-receptor interactions that are generally in good agreement with site-directed mutagenesis and ligand-binding studies presented in the literature. Our results indicate that the binding conformation of the antagonists differs from that of the agonists. This difference can be linked to the activation or inhibition of the receptor.
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MESH Headings
- Binding Sites
- Computer Simulation
- Gonadotropin-Releasing Hormone/analogs & derivatives
- Gonadotropin-Releasing Hormone/chemistry
- Humans
- Models, Chemical
- Models, Molecular
- Protein Binding
- Protein Conformation
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/analysis
- Receptors, G-Protein-Coupled/antagonists & inhibitors
- Receptors, G-Protein-Coupled/chemistry
- Receptors, LHRH/agonists
- Receptors, LHRH/analysis
- Receptors, LHRH/antagonists & inhibitors
- Receptors, LHRH/chemistry
- Sequence Analysis, Protein/methods
- Triptorelin Pamoate/chemistry
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Affiliation(s)
- J Arvid Söderhäll
- Institute for Molecular Pharmacology, Robert-Rössle-Strasse 10, D-13125 Berlin, Germany
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Knollman PE, Janovick JA, Brothers SP, Conn PM. Parallel Regulation of Membrane Trafficking and Dominant-negative Effects by Misrouted Gonadotropin-releasing Hormone Receptor Mutants. J Biol Chem 2005; 280:24506-14. [PMID: 15886197 DOI: 10.1074/jbc.m501978200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Gonadotropin-releasing hormone (GnRH) receptor mutants from patients with hypogonadotropic hypogonadism are frequently misrouted proteins that exert a dominant-negative (DN) effect on human (h) wild-type (WT) receptor, due to oligomerization and retention in the endoplasmic reticulum. Pharmacologic chaperones restore correct folding, rescuing mutants and WT receptor from this oligomer. Rat WT retains the ability to oligomerize (since human and mouse mutants exert a DN effect on rat (r) WT sequence) but, unlike human or mouse, escapes the DN effect of GnRH receptor (Gn-RHR) mutants because rGnRHR mutants route to the plasma membrane with higher efficiency than mouse or human mutants. These distinct behaviors of mouse and rat GnRHRs (distinguished by only four semi- or non-conservative amino acid differences) led us to assess the role of each amino acid. The difference in both routing and the DN effect appears mediated primarily by Ser(216) in the rGnRHR. The homologous amino acid in the hGn-RHR is also Ser and is compensated for by the primate-unique insertion of Lys(191) that, alone, dramatically decreases routing of the receptor. These studies establish the relation between the DN effect and altered receptor trafficking and explain why hGnRHR is more susceptible to defective trafficking by disease-related point mutations than rodent counterparts.
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Affiliation(s)
- Paul E Knollman
- Division of Neuroscience and Reproductive Biology, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon 97006, USA
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Leaños-Miranda A, Ulloa-Aguirre A, Janovick JA, Conn PM. In vitro coexpression and pharmacological rescue of mutant gonadotropin-releasing hormone receptors causing hypogonadotropic hypogonadism in humans expressing compound heterozygous alleles. J Clin Endocrinol Metab 2005; 90:3001-8. [PMID: 15728205 DOI: 10.1210/jc.2004-2071] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
We analyzed the function of mutant GnRH receptor (GnRHR) pairs associated with compound heterozygous patients showing complete or partial forms of hypogonadotropic hypogonadism. We did this to examine potential interactions between misfolded mutants that may influence net receptor function and response to pharmacological rescue. Nine pairs of GnRHR mutants and an unreported combination (L314X((stop))/R262Q) were studied. Coexpression of each pair of mutants in COS-7 cells resulted in an active predominant effect (Q106R/L266R, A171T/Q106R, T32I/C200Y, and R262Q/A129D mutant GnRHR pairs), an additive effect (R262Q/Q106R, N10K/Q106R, and R262Q/Y284C human GnRHR pairs), or a dominant-negative effect (L314X((stop))/Q106R, Q106R+S217R/R262Q, and L314X((stop))/R262Q GnRHRs). For all combinations, addition of the pharmacoperone IN3 increased both agonist binding and effector coupling. The IN3 response was unpredictable because responses could be either similar, higher, or lower, compared with that exhibited by the less affected mutant. The clinical phenotype in patients expressing complex heterozygous alleles appears to be dictated by both the contribution from each mutant and a dominant-negative effect similar to that reported for mutants and wild-type receptor. Depending on the genotype, partial or full restoration of receptor function in response to pharmacological chaperones may be achievable goals in patients bearing inactivating mutations in the GnRHR gene.
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Affiliation(s)
- Alfredo Leaños-Miranda
- Research Unit in Reproductive Medicine, Instituto Mexicano del Seguro Social, México DF, Mexico
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Cheng CK, Leung PCK. Molecular biology of gonadotropin-releasing hormone (GnRH)-I, GnRH-II, and their receptors in humans. Endocr Rev 2005; 26:283-306. [PMID: 15561800 DOI: 10.1210/er.2003-0039] [Citation(s) in RCA: 174] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In human beings, two forms of GnRH, termed GnRH-I and GnRH-II, encoded by separate genes have been identified. Although these hormones share comparable cDNA and genomic structures, their tissue distribution and regulation of gene expression are significantly dissimilar. The actions of GnRH are mediated by the GnRH receptor, which belongs to a member of the rhodopsin-like G protein-coupled receptor superfamily. However, to date, only one conventional GnRH receptor subtype (type I GnRH receptor) uniquely lacking a carboxyl-terminal tail has been found in the human body. Studies on the transcriptional regulation of the human GnRH receptor gene have indicated that tissue-specific gene expression is mediated by differential promoter usage in various cell types. Functionally, there is growing evidence showing that both GnRH-I and GnRH-II are potentially important autocrine and/or paracrine regulators in some extrapituitary compartments. Recent cloning of a second GnRH receptor subtype (type II GnRH receptor) in nonhuman primates revealed that it is structurally and functionally distinct from the mammalian type I receptor. However, the human type II receptor gene homolog carries a frameshift and a premature stop codon, suggesting that a full-length type II receptor does not exist in humans.
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Affiliation(s)
- Chi Keung Cheng
- Department of Obstetrics and Gynecology, University of British Columbia, Vancouver, British Columbia, Canada V6H 3V5
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32
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Abstract
GnRH and its analogs are used extensively for the treatment of hormone-dependent diseases and assisted reproductive techniques. They also have potential as novel contraceptives in men and women. A thorough delineation of the molecular mechanisms involved in ligand binding, receptor activation, and intracellular signal transduction is kernel to understanding disease processes and the development of specific interventions. Twenty-three structural variants of GnRH have been identified in protochordates and vertebrates. In many vertebrates, three GnRHs and three cognate receptors have been identified with distinct distributions and functions. In man, the hypothalamic GnRH regulates gonadotropin secretion through the pituitary GnRH type I receptor via activation of G(q). In-depth studies have identified amino acid residues in both the ligand and receptor involved in binding, receptor activation, and translation into intracellular signal transduction. Although the predominant coupling of the type I GnRH receptor in the gonadotrope is through productive G(q) stimulation, signal transduction can occur via other G proteins and potentially by G protein-independent means. The eventual selection of intracellular signaling may be specifically directed by variations in ligand structure. A second form of GnRH, GnRH II, conserved in all higher vertebrates, including man, is present in extrahypothalamic brain and many reproductive tissues. Its cognate receptor has been cloned from various vertebrate species, including New and Old World primates. The human gene homolog of this receptor, however, has a frame-shift and stop codon, and it appears that GnRH II signaling occurs through the type I GnRH receptor. There has been considerable plasticity in the use of different GnRHs, receptors, and signaling pathways for diverse functions. Delineation of the structural elements in GnRH and the receptor, which facilitate differential signaling, will contribute to the development of novel interventive GnRH analogs.
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Affiliation(s)
- Robert P Millar
- Medical Research Council Human Reproductive Sciences Unit, Centre for Reproductive Biology, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, Scotland, United Kingdom.
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Abstract
Heterotrimeric G proteins couple seven-transmembrane receptors for diverse extracellular signals to effectors that generate intracellular signals altering cell function. Mutations in the gene encoding the alpha subunit of the G protein-coupling receptors to stimulation of adenylyl cyclase cause developmental abnormalities of bone, as well as hormone resistance (pseudohypoparathyroidism caused by loss-of-function mutations) and hormone hypersecretion (McCune-Albright syndrome caused by gain-of-function mutations). Loss- and gain-of-function mutations in genes encoding G protein-coupled receptors (GPCRs) have been identified as the cause of an increasing number of retinal, endocrine, metabolic, and developmental disorders. GPCRs comprise an evolutionarily conserved gene superfamily ( 1 ). By coupling to heterotrimeric G proteins, GPCRs transduce a wide variety of extracellular signals including monoamine, amino acid, and nucleoside neurotransmitters, as well as photons, chemical odorants, divalent cations, hormones, lipids, peptides and proteins. Following a brief overview of G protein-coupled signal transduction, we review the growing body of evidence that mutations in genes encoding GPCRs and G proteins are an important cause of human disease.
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Affiliation(s)
- Allen M Spiegel
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Kakar SS, Malik MT, Winters SJ, Mazhawidza W. Gonadotropin-releasing hormone receptors: structure, expression, and signaling transduction. VITAMINS AND HORMONES 2004; 69:151-207. [PMID: 15196882 DOI: 10.1016/s0083-6729(04)69006-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Sham S Kakar
- Department of Medicine, University of Louisville, Louisville, Kentucky 40202, USA
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