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Abbas A, Hammad AS, Al-Shafai M. The role of genetic and epigenetic GNAS alterations in the development of early-onset obesity. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2024; 793:108487. [PMID: 38103632 DOI: 10.1016/j.mrrev.2023.108487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 12/06/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
BACKGROUND GNAS (guanine nucleotide-binding protein, alpha stimulating) is an imprinted gene that encodes Gsα, the α subunit of the heterotrimeric stimulatory G protein. This subunit mediates the signalling of a diverse array of G protein-coupled receptors (GPCRs), including the melanocortin 4 receptor (MC4R) that serves a pivotal role in regulating food intake, energy homoeostasis, and body weight. Genetic or epigenetic alterations in GNAS are known to cause pseudohypoparathyroidism in its different subtypes and have been recently associated with isolated, early-onset, severe obesity. Given the diverse biological functions that Gsα serves, multiple molecular mechanisms involving various GPCRs, such as MC4R, β2- and β3-adrenoceptors, and corticotropin-releasing hormone receptor, have been implicated in the pathophysiology of severe, early-onset obesity that results from genetic or epigenetic GNAS changes. SCOPE OF REVIEW This review examines the structure and function of GNAS and provides an overview of the disorders that are caused by defects in this gene and may feature early-onset obesity. Moreover, it elucidates the potential molecular mechanisms underlying Gsα deficiency-induced early-onset obesity, highlighting some of their implications for the diagnosis, management, and treatment of this complex condition. MAJOR CONCLUSIONS Gsα deficiency is an underappreciated cause of early-onset, severe obesity. Therefore, screening children with unexplained, severe obesity for GNAS defects is recommended, to enhance the molecular diagnosis and management of this condition.
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Affiliation(s)
- Alaa Abbas
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, P.O. Box 2713, Doha, Qatar
| | - Ayat S Hammad
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, P.O. Box 2713, Doha, Qatar; Biomedical Research Center, Qatar University, P.O. Box 2713, Doha, Qatar
| | - Mashael Al-Shafai
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, P.O. Box 2713, Doha, Qatar; Biomedical Research Center, Qatar University, P.O. Box 2713, Doha, Qatar.
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Morgan HL, Eid N, Khoshkerdar A, Watkins AJ. Defining the male contribution to embryo quality and offspring health in assisted reproduction in farm animals. Anim Reprod 2020; 17:e20200018. [PMID: 33029211 PMCID: PMC7534566 DOI: 10.1590/1984-3143-ar2020-0018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Assisted reproductive technologies such as artificial insemination have delivered significant benefits for farm animal reproduction. However, as with humans, assisted reproduction in livestock requires the manipulation of the gametes and preimplantation embryo. The significance of this ‘periconception’ period is that it represents the transition from parental genome regulation to that of the newly formed embryo. Environmental perturbations during these early developmental stages can result in persistent changes in embryonic gene expression, fetal organ development and ultimately the long-term health of the offspring. While associations between maternal health and offspring wellbeing are well-defined, the significance of paternal health for the quality of his semen and the post-conception development of his offspring have largely been overlooked. Human and animal model studies have identified sperm epigenetic status (DNA methylation levels, histone modifications and RNA profiles) and seminal plasma-mediated maternal uterine immunological, inflammatory and vascular responses as the two central mechanisms capable of linking paternal health and post-fertilisation development. However, there is a significant knowledge gap about the father’s contribution to the long-term health of his offspring, especially with regard to farm animals. Such insights are essential to ensure the safety of widely used assisted reproductive practices and to gain better understanding of the role of paternal health for the well-being of his offspring. In this article, we will outline the impact of male health on semen quality (both sperm and seminal plasma), reproductive fitness and post-fertilisation offspring development and explore the mechanisms underlying the paternal programming of offspring health in farm animals.
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Affiliation(s)
- Hannah Louise Morgan
- Division of Child Health, Obstetrics and Gynaecology, Queen's Medical Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Nader Eid
- Division of Child Health, Obstetrics and Gynaecology, Queen's Medical Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Afsaneh Khoshkerdar
- Division of Child Health, Obstetrics and Gynaecology, Queen's Medical Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Adam John Watkins
- Division of Child Health, Obstetrics and Gynaecology, Queen's Medical Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom
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Tafaj O, Hann S, Ayturk U, Warman ML, Jüppner H. Mice maintain predominantly maternal Gαs expression throughout life in brown fat tissue (BAT), but not other tissues. Bone 2017; 103:177-187. [PMID: 28694163 PMCID: PMC5943706 DOI: 10.1016/j.bone.2017.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 06/14/2017] [Accepted: 07/01/2017] [Indexed: 11/20/2022]
Abstract
The murine Gnas (human GNAS) locus gives rise to Gαs and different splice variants thereof. The Gαs promoter is not methylated thus allowing biallelic expression in most tissues. In contrast, the alternative first Gnas/GNAS exons and their promoters undergo parent specific methylation, which limits transcription to the non-methylated allele. Pseudohypoparathyroidism type Ia (PHP1A) or type Ib (PHP1B) are caused by heterozygous maternal GNAS mutations suggesting that little or no Gαs is derived in some tissues from the non-mutated paternal GNAS thereby causing hormonal resistance. Previous data had indicated that Gαs is mainly derived from the maternal Gnas allele in brown adipose tissue (BAT) of newborn mice, yet it is biallelically expressed in adult BAT. This suggested that paternal Gαs expression is regulated by an unknown factor(s) that varies considerably with age. To extend these findings, we now used a strain-specific SNP in Gnas exon 11 (rs13460569) for evaluation of parent-specific Gαs expression through the densitometric quantification of BanII-digested RT-PCR products and digital droplet PCR (ddPCR). At all investigated ages, Gαs transcripts were derived in BAT predominantly from the maternal Gnas allele, while kidney and liver showed largely biallelic Gαs expression. Only low or undetectable levels of other paternally Gnas-derived transcripts were observed, making it unlikely that these are involved in regulating paternal Gαs expression. Our findings suggest that a cis-acting factor could be implicated in reducing paternal Gαs expression in BAT and presumably in proximal renal tubules, thereby causing PTH-resistance if the maternal GNAS/Gnas allele is mutated.
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Affiliation(s)
- Olta Tafaj
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Steven Hann
- Department of Orthopedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Ugur Ayturk
- Department of Orthopedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Matthew L Warman
- Department of Orthopedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Harald Jüppner
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Pediatric Nephrology Unit, Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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Grüters-Kieslich A, Reyes M, Sharma A, Demirci C, DeClue TJ, Lankes E, Tiosano D, Schnabel D, Jüppner H. Early-Onset Obesity: Unrecognized First Evidence for GNAS Mutations and Methylation Changes. J Clin Endocrinol Metab 2017; 102:2670-2677. [PMID: 28453643 PMCID: PMC5546863 DOI: 10.1210/jc.2017-00395] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 04/17/2017] [Indexed: 12/16/2022]
Abstract
Context Early-onset obesity, characteristic for disorders affecting the leptin-melanocortin pathway, is also observed in pseudohypoparathyroidism type 1A (PHP1A), a disorder caused by maternal GNAS mutations that disrupt expression or function of the stimulatory G protein α-subunit (Gsα). Mutations and/or epigenetic abnormalities at the same genetic locus are also the cause of pseudohypoparathyroidism type 1B (PHP1B). However, although equivalent biochemical and radiographic findings can be encountered in these related disorders caused by GNAS abnormalities, they are considered distinct clinical entities. Objectives To further emphasize the overlapping features between both disorders, we report the cases of several children, initially brought to medical attention because of unexplained early-onset obesity, in whom PHP1B or PHP1A was eventually diagnosed. Patients and Methods Search for GNAS methylation changes or mutations in cohorts of patients with early-onset obesity. Results Severe obesity had been noted in five infants, with a later diagnosis of PHP1B due to STX16 deletions and/or abnormal GNAS methylation. These findings prompted analysis of 24 unselected obese patients, leading to the discovery of inherited STX16 deletions in 2 individuals. Similarly, impressive early weight gains were noted in five patients, who initially lacked additional Albright hereditary osteodystrophy features but in whom PHP1A due to GNAS mutations involving exons encoding Gsα was diagnosed. Conclusions Obesity during the first year of life can be the first clinical evidence for PHP1B, expanding the spectrum of phenotypic overlap between PHP1A and PHP1B. Importantly, GNAS methylation abnormalities escape detection by targeted or genome-wide sequencing strategies, raising the question of whether epigenetic GNAS analyses should be considered for unexplained obesity.
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Affiliation(s)
- Annette Grüters-Kieslich
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
- Department of Pediatric Endocrinology and Diabetes, Charité-Universitätsmedizin, Berlin 10117, Germany
| | - Monica Reyes
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Amita Sharma
- Pediatric Nephrology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Cem Demirci
- Pediatric Endocrinology, Connecticut Children’s Medical Center, University of Connecticut School of Medicine, Farmington, Connecticut 06030
| | | | - Erwin Lankes
- Department of Pediatric Endocrinology and Diabetes, Charité-Universitätsmedizin, Berlin 10117, Germany
- Center for Chronically Sick Children, Charité-Universitätsmedizin, Berlin 10117, Germany
| | - Dov Tiosano
- Division of Pediatric Endocrinology, Meyer Children's Hospital, Rambam Health Care Campus, Haifa 31096, Israel
| | - Dirk Schnabel
- Department of Pediatric Endocrinology and Diabetes, Charité-Universitätsmedizin, Berlin 10117, Germany
- Center for Chronically Sick Children, Charité-Universitätsmedizin, Berlin 10117, Germany
| | - Harald Jüppner
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
- Pediatric Nephrology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
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Bréhin AC, Colson C, Maupetit-Méhouas S, Grybek V, Richard N, Linglart A, Kottler ML, Jüppner H. Loss of methylation at GNAS exon A/B is associated with increased intrauterine growth. J Clin Endocrinol Metab 2015; 100:E623-31. [PMID: 25603460 PMCID: PMC4399294 DOI: 10.1210/jc.2014-4047] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 01/14/2015] [Indexed: 01/26/2023]
Abstract
CONTEXT GNAS is one of few genetic loci that undergo allelic-specific methylation resulting in the parent-specific expression of at least four different transcripts. Due to monoallelic expression, heterozygous GNAS mutations affecting either paternally or maternally derived transcripts cause different forms of pseudohypoparathyroidism (PHP), including autosomal-dominant PHP type Ib (AD-PHP1B) associated with loss of methylation (LOM) at exon A/B alone or sporadic PHP1B (sporPHP1B) associated with broad GNAS methylation changes. Similar to effects other imprinted genes have on early development, we recently observed severe intrauterine growth retardation in newborns, later diagnosed with pseudopseudohypoparathyroidism (PPHP) because of paternal GNAS loss-of-function mutations. OBJECTIVES This study aimed to determine whether GNAS methylation abnormalities affect intrauterine growth. PATIENTS AND METHODS Birth parameters were collected of patients who later developed sporPHP1B or AD-PHP1B, and of their healthy siblings. Comparisons were made to newborns affected by PPHP or PHP1A. RESULTS As newborns, AD-PHP1B patients were bigger than their healthy siblings and well above the reference average; increased sizes were particularly evident if the mothers were unaffected carriers of STX16 deletions. SporPHP1B newborns were slightly above average for weight and length, but their overgrowth was less pronounced than that of AD-PHP1B newborns from unaffected mothers. CONCLUSION LOM at GNAS exon A/B due to maternal STX16 deletions and the resulting biallelic A/B expression are associated with enhanced fetal growth. These findings are distinctly different from those of PPHP patients with paternal GNAS exons 2-13 mutations, whose birth parameters are almost 4.5 z-scores below those of AD-PHP1B patients born to healthy mothers.
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Affiliation(s)
- Anne-Claire Bréhin
- Department of Genetics (A.-C.B., C.C., N.R., M.-L.K.), Centre Hospitalier Universitaire de Caen, Reference Centre for Rare Disorders of Calcium and Phosphorus Metabolism, F-14000 Caen, France; Paediatric Endocrinology and Diabetology (S.M.-M., V.G., A.L.), Reference Centre for Rare Disorders of the Mineral Metabolism, AP-HP Hôpital Bicêtre, le Kremlin-Bicêtre 94270, France; Faculté de Médecine, Université Paris Sud, le Kremlin-Bicêtre 94270, France; and Pediatric Nephrology Unit and Endocrine Unit (H.J.), Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
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Congras A, Yerle-Bouissou M, Pinton A, Vignoles F, Liaubet L, Ferchaud S, Acloque H. Sperm DNA methylation analysis in swine reveals conserved and species-specific methylation patterns and highlights an altered methylation at the GNAS locus in infertile boars. Biol Reprod 2014; 91:137. [PMID: 25320151 DOI: 10.1095/biolreprod.114.119610] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Male infertility is an increasing health issue in today's society for both human and livestock populations. In livestock, male infertility slows the improvement of animal selection programs and agricultural productivity. There is increasing evidence that epigenetic marks play an important role in the production of good-quality sperm. We therefore screened for specific or common epigenetic signatures of livestock infertility. To do so, we compared DNA methylation level in sperm DNA from fertile and infertile boars. We evaluated first the global level of sperm DNA methylation and found no difference between the two groups of boars. We then selected 42 loci of interest, most of them known to be imprinted in human or mice, and assessed the imprinting status of five of them not previously described in swine tissues: WT1, CNTN3, IMPACT, QPCT, and GRB10. DNA methylation level was then quantified in fertile and infertile boars at these 42 loci. Results from fertile boars indicated that the methylation level of the selected loci is highly conserved between pig, human, and mice, with a few exceptions, including the POU5F1 (OCT4) promoter and RTL1. Comparison between fertile and infertile boars revealed that one imprinted region, the GNAS locus, shows an increase in sperm DNA methylation in three out of eight infertile boars with low semen quality. This increase in DNA methylation is associated with an altered expression of the genes belonging to the GNAS locus, suggesting a new role for GNAS in the proper formation of functional gametes.
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Affiliation(s)
- Annabelle Congras
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, GenPhySE, Castanet-Tolosan, France
| | - Martine Yerle-Bouissou
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, GenPhySE, Castanet-Tolosan, France
| | - Alain Pinton
- Université de Toulouse INPT ENVT, UMR1388 Génétique Physiologie et Systèmes d'Elevage GenPhySE, Toulouse, France
| | - Florence Vignoles
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, GenPhySE, Castanet-Tolosan, France
| | - Laurence Liaubet
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, GenPhySE, Castanet-Tolosan, France
| | - Stéphane Ferchaud
- UE1372 GenESI Génétique, Expérimentation et Système Innovants, Surgères, France
| | - Hervé Acloque
- INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, GenPhySE, Castanet-Tolosan, France
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