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Renard E, Thevenard-Berger A, Meyre D. Medical semiology of patients with monogenic obesity: A systematic review. Obes Rev 2024:e13797. [PMID: 38956946 DOI: 10.1111/obr.13797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 03/20/2024] [Accepted: 06/19/2024] [Indexed: 07/04/2024]
Abstract
Patients with monogenic obesity display numerous medical features on top of hyperphagic obesity, but no study to date has provided an exhaustive description of their semiology. Two reviewers independently conducted a systematic review of MEDLINE, Embase, and Web of Science Core Collection databases from inception to January 2022 to identify studies that described symptoms of patients carrying pathogenic mutations in at least one of eight monogenic obesity genes (ADCY3, LEP, LEPR, MC3R, MC4R, MRAP2, PCSK1, and POMC). Of 5207 identified references, 269 were deemed eligible after title and abstract screening, full-text reading, and risk of bias and quality assessment. Data extraction included mutation spectrum and mode of inheritance, clinical presentation (e.g., anthropometry, energy intake and eating behaviors, digestive function, puberty and fertility, cognitive features, infectious diseases, morphological characteristics, chronic respiratory disease, and cardiovascular disease), biological characteristics (metabolic profile, endocrinology, hematology), radiological features, and treatments. The review provides an exhaustive description of mandatory, non-mandatory, and unique symptoms in heterozygous and homozygous carriers of mutation in eight monogenic obesity genes. This information is critical to help clinicians to orient genetic testing in subsets of patients with suspected monogenic obesity and provide actionable treatments (e.g., recombinant leptin and MC4R agonist).
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Affiliation(s)
- Emeline Renard
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, Nancy, France
- Department of Pediatrics, University Hospital of Nancy, Nancy, France
| | | | - David Meyre
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, Nancy, France
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, and Nutrition, University Hospital of Nancy, Nancy, France
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
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2
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Ong SG, Dehghan R, Dorajoo R, Liu JJ, Sng AA, Lee YS, Ooi DSQ. Novel Melanocortin-3 and -4 Receptor Functional Variants in Asian Children With Severe Obesity. J Clin Endocrinol Metab 2024; 109:e1249-e1259. [PMID: 37820740 DOI: 10.1210/clinem/dgad602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 10/13/2023]
Abstract
CONTEXT Genetic variants in melanocortin 3 receptor (MC3R) and melanocortin 4 receptor (MC4R) genes are strongly associated with childhood obesity. OBJECTIVE This study aims to identify and functionally characterize MC3R and MC4R variants in an Asian cohort of children with severe early-onset obesity. METHODS Whole-exome sequencing was performed to screen for MC3R and MC4R coding variants in 488 Asian children with severe early-onset obesity (body mass index for age ≥97th percentile). Functionality of the identified variants were determined via measurement of intracellular cyclic adenosine monophosphate (cAMP) concentrations and luciferase activity. RESULTS Four MC3R and 2 MC4R heterozygous nonsynonymous rare variants were detected. There were 3 novel variants: MC3R c.151G > C (p.Val51Leu), MC4R c.127C > A (p.Gln43Lys), and MC4R c.272T > G (p.Met91Arg), and 3 previously reported variants: MC3R c.127G > A (p.Glu43Lys), MC3R c.97G > A (p.Ala33Thr), and MC3R c.437T > A (p.Ile146Asn). Both MC3R c.127G > A (p.Glu43Lys) and MC4R c.272T > G (p.Met91Arg) variants demonstrated defective downstream cAMP signaling activity. The MC4R c.127C > A (p.Gln43Lys) variant showed reduced cAMP signaling activity at low substrate concentration but the signaling activity was restored at high substrate concentration. The MC3R c.151G > C (p.Val51Leu) variant did not show a significant reduction in cAMP signaling activity compared to wild-type (WT) MC3R. Coexpression studies of the WT and variant MC3R/MC4R showed that the heterozygous variants did not exhibit dominant negative effect. CONCLUSION Our functional assays demonstrated that MC3R c.127G > A (p.Glu43Lys) and MC4R c.272T > G (p.Met91Arg) variants might predispose individuals to early-onset obesity, and further studies are needed to establish the causative effect of these variants in the pathogenesis of obesity.
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Affiliation(s)
- Siong Gim Ong
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Division of Paediatric Endocrinology, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore 119228, Singapore
| | - Roghayeh Dehghan
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore 138672, Singapore
- Department of Genetics and Molecular Biology, School of Medicine, University of Medical Science, Isfahan 81746-73461, Iran
| | - Rajkumar Dorajoo
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore 138672, Singapore
| | - Jian-Jun Liu
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore 138672, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Andrew Anjian Sng
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Division of Paediatric Endocrinology, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore 119228, Singapore
| | - Yung Seng Lee
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Division of Paediatric Endocrinology, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore 119228, Singapore
| | - Delicia Shu Qin Ooi
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
- Division of Paediatric Endocrinology, Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore 119228, Singapore
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3
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Delavy M, Sertour N, Patin E, Le Chatelier E, Cole N, Dubois F, Xie Z, Saint-André V, Manichanh C, Walker AW, Quintana-Murci L, Duffy D, d’Enfert C, Bougnoux ME, Consortium MI. Unveiling Candida albicans intestinal carriage in healthy volunteers: the role of micro- and mycobiota, diet, host genetics and immune response. Gut Microbes 2023; 15:2287618. [PMID: 38017705 PMCID: PMC10732203 DOI: 10.1080/19490976.2023.2287618] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 11/21/2023] [Indexed: 11/30/2023] Open
Abstract
Candida albicans is a commensal yeast present in the gut of most healthy individuals but with highly variable concentrations. However, little is known about the host factors that influence colonization densities. We investigated how microbiota, host lifestyle factors, and genetics could shape C. albicans intestinal carriage in 695 healthy individuals from the Milieu Intérieur cohort. C. albicans intestinal carriage was detected in 82.9% of the subjects using quantitative PCR. Using linear mixed models and multiway-ANOVA, we explored C. albicans intestinal levels with regard to gut microbiota composition and lifestyle factors including diet. By analyzing shotgun metagenomics data and C. albicans qPCR data, we showed that Intestinimonas butyriciproducens was the only gut microbiota species whose relative abundance was negatively correlated with C. albicans concentration. Diet is also linked to C. albicans growth, with eating between meals and a low-sodium diet being associated with higher C. albicans levels. Furthermore, by Genome-Wide Association Study, we identified 26 single nucleotide polymorphisms suggestively associated with C. albicans colonization. In addition, we found that the intestinal levels of C. albicans might influence the host immune response, specifically in response to fungal challenge. We analyzed the transcriptional levels of 546 immune genes and the concentration of 13 cytokines after whole blood stimulation with C. albicans cells and showed positive associations between the extent of C. albicans intestinal levels and NLRP3 expression, as well as secreted IL-2 and CXCL5 concentrations. Taken together, these findings open the way for potential new interventional strategies to curb C. albicans intestinal overgrowth.
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Affiliation(s)
- Margot Delavy
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, Université Paris Cité INRAE, Paris, France
| | - Natacha Sertour
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, Université Paris Cité INRAE, Paris, France
| | - Etienne Patin
- Human Evolutionary Genetics Unit, Institut Pasteur, Université Paris Cité, CNRS UMR2000, Paris, France
| | | | - Nathaniel Cole
- The Rowett Institute, University of Aberdeen, Aberdeen, UK
| | - Florian Dubois
- Translational Immunology Unit, Institut Pasteur, Université Paris Cité, Paris, France
- Institut Pasteur, Université Paris Cité, CBUTechS, Paris, France
| | - Zixuan Xie
- Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Gut Microbiome Group, Barcelona, Spain
| | - Violaine Saint-André
- Translational Immunology Unit, Institut Pasteur, Université Paris Cité, Paris, France
- Bioinformatics and Biostatistics HUB, Department of Computational Biology, Institut Pasteur, Université Paris Cité, Paris, France
| | - Chaysavanh Manichanh
- Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Gut Microbiome Group, Barcelona, Spain
| | - Alan W. Walker
- The Rowett Institute, University of Aberdeen, Aberdeen, UK
| | - Lluis Quintana-Murci
- Human Evolutionary Genetics Unit, Institut Pasteur, Université Paris Cité, CNRS UMR2000, Paris, France
| | - Darragh Duffy
- Translational Immunology Unit, Institut Pasteur, Université Paris Cité, Paris, France
- Institut Pasteur, Université Paris Cité, CBUTechS, Paris, France
| | - Christophe d’Enfert
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, Université Paris Cité INRAE, Paris, France
| | - Marie-Elisabeth Bougnoux
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, Université Paris Cité INRAE, Paris, France
- APHP, Hôpital Necker-Enfants-Malades, Service de Microbiologie Clinique, Unité de Parasitologie-Mycologie, Paris, France
| | - Milieu Intérieur Consortium
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, Université Paris Cité INRAE, Paris, France
- Human Evolutionary Genetics Unit, Institut Pasteur, Université Paris Cité, CNRS UMR2000, Paris, France
- MGP MetaGénoPolis, INRA, Université Paris-Saclay, Jouy-en-Josas, France
- The Rowett Institute, University of Aberdeen, Aberdeen, UK
- Translational Immunology Unit, Institut Pasteur, Université Paris Cité, Paris, France
- Institut Pasteur, Université Paris Cité, CBUTechS, Paris, France
- Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, Gut Microbiome Group, Barcelona, Spain
- Bioinformatics and Biostatistics HUB, Department of Computational Biology, Institut Pasteur, Université Paris Cité, Paris, France
- APHP, Hôpital Necker-Enfants-Malades, Service de Microbiologie Clinique, Unité de Parasitologie-Mycologie, Paris, France
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4
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Zheng Y, Rajcsanyi LS, Peters T, Dempfle A, Wudy SA, Hebebrand J, Hinney A. Evaluation of the MC3R gene pertaining to body weight and height regulation and puberty development. Sci Rep 2023; 13:10419. [PMID: 37369769 DOI: 10.1038/s41598-023-37344-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 06/20/2023] [Indexed: 06/29/2023] Open
Abstract
Recent studies reported an impact of the melanocortin 3 receptor (MC3R) on the regulation of body weight, linear growth and puberty timing. Previously, allele p.44Ile of a frequent non-synonymous variant (NSV) p.Val44Ile was reported to be associated with decreased lean body mass (LBM) and later puberty in both sexes. We Sanger sequenced the coding region of MC3R in 185 children or adolescents with short normal stature (SNS) or 258 individuals with severe obesity, and 192 healthy-lean individuals. Eleven variants (six NSVs) were identified. In-silico analyses ensued. Three rare loss-of-function (LoF) variants (p.Phe45Ser, p.Arg220Ser and p.Ile298Ser) were only found in severely obese individuals. One novel highly conserved NSV (p.Ala214Val), predicted to increase protein stability, was detected in a single lean female. In the individuals with SNS, we observed deviation from Hardy-Weinberg Equilibrium (HWE) (p = 0.012) for p.Val44Ile (MAF = 11.62%). Homozygous p.44Ile carriers with SNS had an increased BMI, but this effect did not remain significant after Bonferroni correction. In line with previous findings, the detected LoF NSVs may suggest that dysfunction in MC3R is associated with decreased body height, obesity and delayed puberty.
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Affiliation(s)
- Yiran Zheng
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstr. 174, 45147, Essen, Germany.
- Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
| | - Luisa Sophie Rajcsanyi
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstr. 174, 45147, Essen, Germany
- Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Triinu Peters
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstr. 174, 45147, Essen, Germany
- Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Astrid Dempfle
- Institute of Medical Informatics and Statistics, Kiel University, Kiel, Germany
| | - Stefan A Wudy
- Division of Pediatric Endocrinology and Diabetology, Center of Child and Adolescent Medicine, Justus Liebig University, Giessen, Germany
| | - Johannes Hebebrand
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstr. 174, 45147, Essen, Germany
- Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Anke Hinney
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstr. 174, 45147, Essen, Germany
- Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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5
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Lam BYH, Williamson A, Finer S, Day FR, Tadross JA, Gonçalves Soares A, Wade K, Sweeney P, Bedenbaugh MN, Porter DT, Melvin A, Ellacott KLJ, Lippert RN, Buller S, Rosmaninho-Salgado J, Dowsett GKC, Ridley KE, Xu Z, Cimino I, Rimmington D, Rainbow K, Duckett K, Holmqvist S, Khan A, Dai X, Bochukova EG, Trembath RC, Martin HC, Coll AP, Rowitch DH, Wareham NJ, van Heel DA, Timpson N, Simerly RB, Ong KK, Cone RD, Langenberg C, Perry JRB, Yeo GS, O'Rahilly S. MC3R links nutritional state to childhood growth and the timing of puberty. Nature 2021; 599:436-441. [PMID: 34732894 PMCID: PMC8819628 DOI: 10.1038/s41586-021-04088-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 10/01/2021] [Indexed: 02/02/2023]
Abstract
The state of somatic energy stores in metazoans is communicated to the brain, which regulates key aspects of behaviour, growth, nutrient partitioning and development1. The central melanocortin system acts through melanocortin 4 receptor (MC4R) to control appetite, food intake and energy expenditure2. Here we present evidence that MC3R regulates the timing of sexual maturation, the rate of linear growth and the accrual of lean mass, which are all energy-sensitive processes. We found that humans who carry loss-of-function mutations in MC3R, including a rare homozygote individual, have a later onset of puberty. Consistent with previous findings in mice, they also had reduced linear growth, lean mass and circulating levels of IGF1. Mice lacking Mc3r had delayed sexual maturation and an insensitivity of reproductive cycle length to nutritional perturbation. The expression of Mc3r is enriched in hypothalamic neurons that control reproduction and growth, and expression increases during postnatal development in a manner that is consistent with a role in the regulation of sexual maturation. These findings suggest a bifurcating model of nutrient sensing by the central melanocortin pathway with signalling through MC4R controlling the acquisition and retention of calories, whereas signalling through MC3R primarily regulates the disposition of calories into growth, lean mass and the timing of sexual maturation.
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Affiliation(s)
- B Y H Lam
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - A Williamson
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - S Finer
- Wolfson Institute of Population Health, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - F R Day
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - J A Tadross
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - A Gonçalves Soares
- MRC Integrative Epidemiology Unit and Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - K Wade
- MRC Integrative Epidemiology Unit and Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - P Sweeney
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - M N Bedenbaugh
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - D T Porter
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - A Melvin
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - K L J Ellacott
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - R N Lippert
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition, Potsdam, Germany
| | - S Buller
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - J Rosmaninho-Salgado
- Medical Genetics Unit, Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - G K C Dowsett
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - K E Ridley
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - Z Xu
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - I Cimino
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - D Rimmington
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - K Rainbow
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - K Duckett
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - S Holmqvist
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - A Khan
- Wolfson Institute of Population Health, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - X Dai
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University London, London, UK
| | - E G Bochukova
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University London, London, UK
| | - R C Trembath
- School of Basic and Medical Biosciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - H C Martin
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - A P Coll
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - D H Rowitch
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - N J Wareham
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - D A van Heel
- Wolfson Institute of Population Health, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University London, London, UK
| | - N Timpson
- MRC Integrative Epidemiology Unit and Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - R B Simerly
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - K K Ong
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - R D Cone
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - C Langenberg
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- Computational Medicine, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - J R B Perry
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - G S Yeo
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - S O'Rahilly
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK.
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK.
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Tenriola A, Hidayah N, Subair S, Massi MN, Handayani I, Natzir R, Djaharuddin I, Halik H. The Significance of Differences in Melanocortin 3 Levels and their Relationship with Pulmonary Tuberculosis and Body Mass Index. Open Access Maced J Med Sci 2021. [DOI: 10.3889/oamjms.2021.6517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND: Melanocortin 3 Receptors (MC3R) levels plays a role in many biological systems, including energy homeostasis and regulation of fat metabolism. However, very few have researched the relationship between MC3R and tuberculosis (TB) and body mass index.
AIM: This study explores the differences in serum MC3R levels in active TB, household contacts, and control groups, as well as at different body mass index status. This study tries to find out the relationship between MC3R and other variables.
METHODS AND MATERIALS: Blood samples were taken from 53 active TB patients, 49 household contacts, and 30 healthy people as controls. The 132 samples were subjected to IGRA and ELISA examinations to determine differences in MC3R levels in all groups.
RESULTS: The highest mean of MC3R levels were found in the active TB group at 1.259.55 (p = 0.028) and had a positive correlation with a value of p = 0.008. In the sex group, men had the highest levels (p = 0.551). In the 30–49 year age group, the median value increased significantly in the three groups (p = 0.028), and there was a correlation between MC3R and the 17–29 year age group, although the correlation was negative (p = 0.021), in the 30–49 year age group with a positive correlation (p = 0.050). The mean MC3R value increased significantly in the overweight group in the three groups (p = 0.006) but did not significantly correlate.
CONCLUSION: The high level of MC3R in TB patients is related to its role as a defence against microbes that enter the body through the immune process to prevent further infection and inflammation. Meanwhile, high levels of MC3R in excess Body mass index were associated with the function of MC3R as an inhibitor of pro-opiomelanocortin (POMC) neurons to release α-MSH.
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7
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Yeo GSH, Chao DHM, Siegert AM, Koerperich ZM, Ericson MD, Simonds SE, Larson CM, Luquet S, Clarke I, Sharma S, Clément K, Cowley MA, Haskell-Luevano C, Van Der Ploeg L, Adan RAH. The melanocortin pathway and energy homeostasis: From discovery to obesity therapy. Mol Metab 2021; 48:101206. [PMID: 33684608 PMCID: PMC8050006 DOI: 10.1016/j.molmet.2021.101206] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 02/28/2021] [Accepted: 03/03/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Over the past 20 years, insights from human and mouse genetics have illuminated the central role of the brain leptin-melanocortin pathway in controlling mammalian food intake, with genetic disruption resulting in extreme obesity, and more subtle polymorphic variations influencing the population distribution of body weight. At the end of 2020, the U.S. Food and Drug Administration (FDA) approved setmelanotide, a melanocortin 4 receptor agonist, for use in individuals with severe obesity due to either pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency. SCOPE OF REVIEW Herein, we chart the melanocortin pathway's history, explore its pharmacology, genetics, and physiology, and describe how a neuropeptidergic circuit became an important druggable obesity target. MAJOR CONCLUSIONS Unravelling the genetics of the subset of severe obesity has revealed the importance of the melanocortin pathway in appetitive control; coupling this with studying the molecular pharmacology of compounds that bind melanocortin receptors has brought a new obesity drug to the market. This process provides a drug discovery template for complex disorders, which for setmelanotide took 25 years to transform from a single gene into an approved drug.
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Affiliation(s)
- Giles S H Yeo
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | | | - Anna-Maria Siegert
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | - Zoe M Koerperich
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Mark D Ericson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Stephanie E Simonds
- Metabolism, Diabetes, and Obesity Programme, Monash Biomedicine Discovery Institute, and Department of Physiology, Monash University, Clayton, Victoria, Australia.
| | - Courtney M Larson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Serge Luquet
- Université de Paris, BFA, UMR 8251, CNRS, Paris, France.
| | - Iain Clarke
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3010, Australia.
| | | | - Karine Clément
- Assistance Publique Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, Paris, France, Sorbonne Université, INSERM, Nutrition and Obesity: Systemic Approaches (NutriOmics) Research Unit, Paris, France.
| | - Michael A Cowley
- Metabolism, Diabetes, and Obesity Programme, Monash Biomedicine Discovery Institute, and Department of Physiology, Monash University, Clayton, Victoria, Australia.
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | | | - Roger A H Adan
- Department of Translational Neuroscience, UMCU Brain Centre, University Medical Centre Utrecht, Utrecht University, the Netherlands; Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Sweden.
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8
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Chang M, Chen B, Shaffner J, Dworkin LD, Gong R. Melanocortin System in Kidney Homeostasis and Disease: Novel Therapeutic Opportunities. Front Physiol 2021; 12:651236. [PMID: 33716796 PMCID: PMC7943476 DOI: 10.3389/fphys.2021.651236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 02/03/2021] [Indexed: 12/30/2022] Open
Abstract
Melanocortin peptides, melanocortin receptors, melanocortin receptor accessory proteins, and endogenous antagonists of melanocortin receptors are the key components constituting the melanocortin hormone system, one of the most complex and important hormonal systems in our body. A plethora of evidence suggests that melanocortins possess a protective activity in a variety of kidney diseases in both rodent models and human patients. In particular, the steroidogenic melanocortin peptide adrenocorticotropic hormone (ACTH), has been shown to exert a beneficial effect in a number of kidney diseases, possibly via a mechanism independent of its steroidogenic activity. In patients with steroid-resistant nephrotic glomerulopathy, ACTH monotherapy is still effective in inducing proteinuria remission. This has inspired research on potential implications of the melanocortin system in glomerular diseases. However, our understanding of the role of the melanocortinergic pathway in kidney disease is very limited, and there are still huge unknowns to be explored. The most controversial among these is the identification of effector cells in the kidney as well as the melanocortin receptors responsible for conveying the renoprotective action. This review article introduces the melanocortin hormone system, summarizes the existing evidence for the expression of melanocortin receptors in the kidney, and evaluates the potential strategy of melanocortin therapy for kidney disease.
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Affiliation(s)
- Mingyang Chang
- Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, OH, United States
| | - Bohan Chen
- Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, OH, United States
| | - James Shaffner
- Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, OH, United States
| | - Lance D Dworkin
- Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, OH, United States
| | - Rujun Gong
- Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, OH, United States
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9
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Wang W, Lin YJ, Chen ZX, Guo DY. Identification and characterization of two novel melanocortin-3 receptor mutations in Chinese obese individuals. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166107. [PMID: 33621651 DOI: 10.1016/j.bbadis.2021.166107] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/31/2021] [Accepted: 02/17/2021] [Indexed: 11/17/2022]
Abstract
The melanocortin-3 receptor (MC3R) and melanocortin-4 receptor (MC4R), known as neural melanocortin receptors, have been implicated to be critical components of the hypothalamic leptin-melanocortin pathway and related to obesity pathogenesis. In contrast to extensive evidence from physiologic, biological, genetic studies demonstrating that MC4R is a critical regulator in obesity, whether MC3R mutation causes obesity is still controversial. In the present study, we screened for coding variants in the MC3R gene of 176 obese individuals (mean BMI 34.84 ± 0.19 kg/m2) and 170 lean controls (mean BMI 20.70 ± 0.08 kg/m2) to assess the prevalence of MC3R mutations in a Chinese cohort. Two novel mutations, A33D (c.C98 > A) and A259T (c.G775 > A), were identified in two subjects with morbid obesity, respectively. A259T was also identified in the carrier's sibling. In vitro functional studies showed that A33D was defective in the cAMP signaling pathway, whereas A259T MC3R had defective maximal binding and cAMP generation in response to NDP- and α-MSH, likely due to decreased cell surface expression. In addition, we showed that A33D and A259T were biased receptors and defect in constitutive activation of ERK1/2 signaling through MC3R might be a cause for morbid obesity. Our sequencing and co-segregation studies combined with comprehensive functional analysis demonstrated that A259T might be predisposing to obesity. Further investigations in larger cohorts will be needed in order to define this association and the specific phenotypic characteristics resulting from these mutations.
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Affiliation(s)
- Wei Wang
- Department of Clinical laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., 128 Hetongli Rd, Huli District, Xiamen 361000, China.
| | - Yue-Jun Lin
- Department of Clinical laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., 128 Hetongli Rd, Huli District, Xiamen 361000, China
| | - Zhao-Xia Chen
- Department of Clinical laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., 128 Hetongli Rd, Huli District, Xiamen 361000, China
| | - Dong-Yu Guo
- Department of Clinical laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., 128 Hetongli Rd, Huli District, Xiamen 361000, China.
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10
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Rare genetic forms of obesity: From gene to therapy. Physiol Behav 2020; 227:113134. [DOI: 10.1016/j.physbeh.2020.113134] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 07/15/2020] [Accepted: 07/21/2020] [Indexed: 01/05/2023]
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11
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Ehtesham S, Qasim A, Meyre D. Loss-of-function mutations in the melanocortin-3 receptor gene confer risk for human obesity: A systematic review and meta-analysis. Obes Rev 2019; 20:1085-1092. [PMID: 31090190 DOI: 10.1111/obr.12864] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 03/20/2019] [Accepted: 03/21/2019] [Indexed: 02/06/2023]
Abstract
The association between rare coding loss-of-function (LOF) mutations in the melanocortin receptor 3 (MC3R) gene and human obesity is controversial. To fill this gap of knowledge, we performed a systematic review and meta-analysis of genetic association studies in all ages and ethnicities. Two reviewers independently performed risk of bias assessment and extracted data. We searched Medline, Embase, Web of Science Core Collection, BIOSIS Preview, CINAHL, ProQuest Dissertations & Theses, and reference lists of relevant studies. All case-control, cross-sectional, prospective, and retrospective studies that evaluated prevalence of rare (less than 1% frequency) coding partial/complete LOF mutations in MC3R among individuals with obesity and normal weight were included. Our systematic search identified 1925 references relevant to the present review. Six studies were deemed eligible. Meta-analysis of 2969 individuals with obesity and 2572 with normal weight showed a positive association between rare heterozygous coding partial/complete LOF mutations in MC3R and obesity in children and adults of European, North African, and Asian ancestries (odds ratio = 3.07; 95% CI, 1.48-7.00; P = 4.2 × 10-3 ). Our data demonstrates that rare partial/complete LOF mutations in the coding region of MC3R confer three-time increased risk of obesity in humans, and implies that rare genetic variants with intermediate effects contribute to the missing heritability of obesity.
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Affiliation(s)
- Sahar Ehtesham
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
| | - Anila Qasim
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
| | - David Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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12
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Yuan XC, Tao YX. Fenoprofen-An Old Drug Rediscovered as a Biased Allosteric Enhancer for Melanocortin Receptors. ACS Chem Neurosci 2019; 10:1066-1074. [PMID: 30168706 DOI: 10.1021/acschemneuro.8b00347] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
It is time-consuming and costly to bring new drugs to market, making it necessary and urgent to exploit existing drugs for new uses. Recently, fenoprofen was demonstrated as an allosteric modulator at melanocortin receptors (MCRs), although the exact mode of action has not been clarified. MCRs regulate multiple functions, including pigmentation, adrenal steroidogenesis, inflammation, energy homeostasis, and exocrine gland secretion. In this study, we showed that fenoprofen failed to displace the orthosteric agonist Nle4-d-Phe7-α-melanocyte stimulating hormone from binding to MC3-5R while possessing positive allosteric modulator activities at these receptors. In addition, fenoprofen induced biased signaling at MC3-5R, as it selectively activated ERK1/2 cascade but not the canonical cAMP signaling. Notably, fenoprofen stimulated biased signaling at MC3-5R, but not at MC1R, hence acting selectively among this highly conserved family of receptors. Moreover, PAM activity and biased signaling induced by fenoprofen were observed not only at wild-type but also at naturally occurring mutant MC3Rs, suggesting that this biased allosteric enhancer action might constitute as novel therapeutic opportunity for obese patients harboring these mutations. Our study might guide novel therapeutic applications for repurposing current drugs or designing new drugs combining allosteric and biased properties.
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Affiliation(s)
- Xiao-Chen Yuan
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036 Anhui, China
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, Alabama 36849, United States
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, Alabama 36849, United States
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13
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14
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Tam V, Turcotte M, Meyre D. Established and emerging strategies to crack the genetic code of obesity. Obes Rev 2019; 20:212-240. [PMID: 30353704 DOI: 10.1111/obr.12770] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 12/11/2022]
Abstract
Tremendous progress has been made in the genetic elucidation of obesity over the past two decades, driven largely by technological, methodological and organizational innovations. Current strategies for identifying obesity-predisposing loci/genes, including cytogenetics, linkage analysis, homozygosity mapping, admixture mapping, candidate gene studies, genome-wide association studies, custom genotyping arrays, whole-exome sequencing and targeted exome sequencing, have achieved differing levels of success, and the identified loci in aggregate explain only a modest fraction of the estimated heritability of obesity. This review outlines the successes and limitations of these approaches and proposes novel strategies, including the use of exceptionally large sample sizes, the study of diverse ethnic groups and deep phenotypes and the application of innovative methods and study designs, to identify the remaining obesity-predisposing genes. The use of both established and emerging strategies has the potential to crack the genetic code of obesity in the not-too-distant future. The resulting knowledge is likely to yield improvements in obesity prediction, prevention and care.
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Affiliation(s)
- V Tam
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - M Turcotte
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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15
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Qasim A, Mayhew AJ, Ehtesham S, Alyass A, Volckmar AL, Herpertz S, Hinney A, Hebebrand J, Meyre D. Gain-of-function variants in the melanocortin 4 receptor gene confer susceptibility to binge eating disorder in subjects with obesity: a systematic review and meta-analysis. Obes Rev 2019; 20:13-21. [PMID: 30306707 DOI: 10.1111/obr.12761] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 07/20/2018] [Accepted: 08/02/2018] [Indexed: 01/21/2023]
Abstract
The association between coding variants in the melanocortin 4 receptor gene (MC4R) and binge eating disorder (BED) in patients with obesity is controversial. Two independent reviewers systematically searched MEDLINE, Embase, PsycINFO, BIOSIS Previews, Web of Science Core Collection and Google Scholar up to February 2018, using terms describing the MC4R gene and BED. Six of 103 identified references were included. Studies examined associations between at least one coding variant/mutation in MC4R and BED and screened for BED as per the Diagnostic and Statistical Manual of Mental Disorders. Risk of bias was assessed using a modified version of the Q-Genie tool, and overall quality of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation guidance. Meta-analysis was conducted via logistic regression models. A positive association between gain-of-function (GOF) variants in the MC4R and BED was observed (odds ratio [OR] = 3.05; 95% confidence interval [CI]: 1.82, 5.04; p = 1.7 × 10-5 ), while no association was detected between loss-of-function (LOF) mutations and BED (OR = 1.50; 95% CI: 0.73, 2.96; p = 0.25). Similar results were found after accounting for study quality (GOF variants: OR = 3.15; 95% CI: 1.76, 5.66; p = 1.1 × 10-4 ; LOF mutations: OR = 1.50; 95% CI: 0.73, 2.97; p = 0.25). Our systematic review and meta-analysis provides evidence that GOF variants as opposed to LOF mutations in MC4R are associated with BED in subjects with obesity.
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Affiliation(s)
- A Qasim
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - A J Mayhew
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - S Ehtesham
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - A Alyass
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - A-L Volckmar
- Department of Child and Adolescent Psychiatry, University Hospital Essen, University of Duisburg - Essen, Essen, Germany
| | - S Herpertz
- Department of Psychosomatic Medicine and Psychotherapy, LWL University Clinic, Ruhr University Bochum, Bochum, Germany
| | - A Hinney
- Department of Child and Adolescent Psychiatry, University Hospital Essen, University of Duisburg - Essen, Essen, Germany
| | - J Hebebrand
- Department of Child and Adolescent Psychiatry, University Hospital Essen, University of Duisburg - Essen, Essen, Germany
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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16
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17
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Serra-Juhé C, Martos-Moreno GÁ, Bou de Pieri F, Flores R, González JR, Rodríguez-Santiago B, Argente J, Pérez-Jurado LA. Novel genes involved in severe early-onset obesity revealed by rare copy number and sequence variants. PLoS Genet 2017; 13:e1006657. [PMID: 28489853 PMCID: PMC5443539 DOI: 10.1371/journal.pgen.1006657] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 05/24/2017] [Accepted: 02/26/2017] [Indexed: 12/26/2022] Open
Abstract
Obesity is a multifactorial disorder with high heritability (50–75%), which is probably higher in early-onset and severe cases. Although rare monogenic forms and several genes and regions of susceptibility, including copy number variants (CNVs), have been described, the genetic causes underlying the disease still remain largely unknown. We searched for rare CNVs (>100kb in size, altering genes and present in <1/2000 population controls) in 157 Spanish children with non-syndromic early-onset obesity (EOO: body mass index >3 standard deviations above the mean at <3 years of age) using SNP array molecular karyotypes. We then performed case control studies (480 EOO cases/480 non-obese controls) with the validated CNVs and rare sequence variants (RSVs) detected by targeted resequencing of selected CNV genes (n = 14), and also studied the inheritance patterns in available first-degree relatives. A higher burden of gain-type CNVs was detected in EOO cases versus controls (OR = 1.71, p-value = 0.0358). In addition to a gain of the NPY gene in a familial case with EOO and attention deficit hyperactivity disorder, likely pathogenic CNVs included gains of glutamate receptors (GRIK1, GRM7) and the X-linked gastrin-peptide receptor (GRPR), all inherited from obese parents. Putatively functional RSVs absent in controls were also identified in EOO cases at NPY, GRIK1 and GRPR. A patient with a heterozygous deletion disrupting two contiguous and related genes, SLCO4C1 and SLCO6A1, also had a missense RSV at SLCO4C1 on the other allele, suggestive of a recessive model. The genes identified showed a clear enrichment of shared co-expression partners with known genes strongly related to obesity, reinforcing their role in the pathophysiology of the disease. Our data reveal a higher burden of rare CNVs and RSVs in several related genes in patients with EOO compared to controls, and implicate NPY, GRPR, two glutamate receptors and SLCO4C1 in highly penetrant forms of familial obesity. Although there is strong evidence for a high genetic component of obesity, the underlying genetic causes are largely unknown, mostly due to the highly heterogeneous nature of the disorder. In this work, we have focused on the most severe end of the spectrum, severe obesity with early-onset in childhood, which is more likely due to genetic alterations. We screened for rare copy number variation (CNV) a sample of 157 Spanish children with early-onset obesity using molecular karyotypes and then studied the genes altered by CNVs in 480 cases and 480 non-obese controls. We identified a higher burden of gain-type CNVs in cases as well as several CNVs and sequence variants that were specific of the obese population. Interestingly, the genes identified shared co-expression partners with known obesity genes. Among those, the genes encoding the neuropeptide Y (NPY), two glutamate receptors (GRIK1, GRM7), the X-linked gastrin-peptide receptor (GRPR), and the organic anion transporter (SLCO4C1) are novel obesity candidate genes that may contribute to highly penetrant forms of familial obesity.
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Affiliation(s)
- Clara Serra-Juhé
- Genetics Unit, Universitat Pompeu Fabra, Barcelona, Spain
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Gabriel Á. Martos-Moreno
- Departments of Pediatrics & Pediatric Endocrinology, Hospital Infantil Universitario Niño Jesús, Universidad Autónoma de Madrid, Madrid, Spain
- Hospital de la Princesa Research Institute, Madrid, Spain
- Centro de Investigación Biomédica en Red de fisiopatología de la obesidad y nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Francesc Bou de Pieri
- Genetics Unit, Universitat Pompeu Fabra, Barcelona, Spain
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Raquel Flores
- Genetics Unit, Universitat Pompeu Fabra, Barcelona, Spain
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | - Juan R. González
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Center for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Barcelona, Spain
| | | | - Jesús Argente
- Departments of Pediatrics & Pediatric Endocrinology, Hospital Infantil Universitario Niño Jesús, Universidad Autónoma de Madrid, Madrid, Spain
- Hospital de la Princesa Research Institute, Madrid, Spain
- Centro de Investigación Biomédica en Red de fisiopatología de la obesidad y nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, CEI UAM & CSIC, Madrid, Spain
- * E-mail: (LAPJ); (JA)
| | - Luis A. Pérez-Jurado
- Genetics Unit, Universitat Pompeu Fabra, Barcelona, Spain
- Hospital del Mar Research Institute (IMIM), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
- * E-mail: (LAPJ); (JA)
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18
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Recent progress in genetics, epigenetics and metagenomics unveils the pathophysiology of human obesity. Clin Sci (Lond) 2017; 130:943-86. [PMID: 27154742 DOI: 10.1042/cs20160136] [Citation(s) in RCA: 227] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 02/24/2016] [Indexed: 12/19/2022]
Abstract
In high-, middle- and low-income countries, the rising prevalence of obesity is the underlying cause of numerous health complications and increased mortality. Being a complex and heritable disorder, obesity results from the interplay between genetic susceptibility, epigenetics, metagenomics and the environment. Attempts at understanding the genetic basis of obesity have identified numerous genes associated with syndromic monogenic, non-syndromic monogenic, oligogenic and polygenic obesity. The genetics of leanness are also considered relevant as it mirrors some of obesity's aetiologies. In this report, we summarize ten genetically elucidated obesity syndromes, some of which are involved in ciliary functioning. We comprehensively review 11 monogenic obesity genes identified to date and their role in energy maintenance as part of the leptin-melanocortin pathway. With the emergence of genome-wide association studies over the last decade, 227 genetic variants involved in different biological pathways (central nervous system, food sensing and digestion, adipocyte differentiation, insulin signalling, lipid metabolism, muscle and liver biology, gut microbiota) have been associated with polygenic obesity. Advances in obligatory and facilitated epigenetic variation, and gene-environment interaction studies have partly accounted for the missing heritability of obesity and provided additional insight into its aetiology. The role of gut microbiota in obesity pathophysiology, as well as the 12 genes associated with lipodystrophies is discussed. Furthermore, in an attempt to improve future studies and merge the gap between research and clinical practice, we provide suggestions on how high-throughput '-omic' data can be integrated in order to get closer to the new age of personalized medicine.
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Demidowich AP, Jun JY, Yanovski JA. Polymorphisms and mutations in the melanocortin-3 receptor and their relation to human obesity. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2468-2476. [PMID: 28363697 DOI: 10.1016/j.bbadis.2017.03.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 12/18/2022]
Abstract
Inactivating mutations in the melanocortin 3 receptor (Mc3r) have been described as causing obesity in mice, but the physiologic effects of MC3R mutations in humans have been less clear. Here we review the MC3R polymorphisms and mutations identified in humans, and the in vitro, murine, and human cohort studies examining their putative effects. Some, but not all, studies suggest that the common human MC3R variant T6K+V81I, as well as several other rare, function-altering mutations, are associated with greater adiposity and hyperleptinemia with altered energy partitioning. In vitro, the T6K+V81I variant appears to decrease MC3R expression and therefore cAMP generation in response to ligand binding. Knockin mouse studies confirm that the T6K+V81I variant increases feeding efficiency and the avidity with which adipocytes derived from bone or adipose tissue stem cells store triglycerides. Other MC3R mutations occur too infrequently in the human population to make definitive conclusions regarding their clinical effects. This article is part of a Special Issue entitled: Melanocortin Receptors - edited by Ya-Xiong Tao.
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Affiliation(s)
- Andrew P Demidowich
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Joo Yun Jun
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Jack A Yanovski
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States.
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Singh RK, Kumar P, Mahalingam K. Molecular genetics of human obesity: A comprehensive review. C R Biol 2017; 340:87-108. [PMID: 28089486 DOI: 10.1016/j.crvi.2016.11.007] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 10/03/2016] [Accepted: 11/10/2016] [Indexed: 12/25/2022]
Abstract
Obesity and its related health complications is a major problem worldwide. Hypothalamus and their signalling molecules play a critical role in the intervening and coordination with energy balance and homeostasis. Genetic factors play a crucial role in determining an individual's predisposition to the weight gain and being obese. In the past few years, several genetic variants were identified as monogenic forms of human obesity having success over common polygenic forms. In the context of molecular genetics, genome-wide association studies (GWAS) approach and their findings signified a number of genetic variants predisposing to obesity. However, the last couple of years, it has also been noticed that alterations in the environmental and epigenetic factors are one of the key causes of obesity. Hence, this review might be helpful in the current scenario of molecular genetics of human obesity, obesity-related health complications (ORHC), and energy homeostasis. Future work based on the clinical discoveries may play a role in the molecular dissection of genetic approaches to find more obesity-susceptible gene loci.
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Affiliation(s)
- Rajan Kumar Singh
- Department of Bio-Medical Sciences, School of Biosciences and Technology, VIT University, 632014 Vellore, India
| | - Permendra Kumar
- Department of Bio-Medical Sciences, School of Biosciences and Technology, VIT University, 632014 Vellore, India
| | - Kulandaivelu Mahalingam
- Department of Bio-Medical Sciences, School of Biosciences and Technology, VIT University, 632014 Vellore, India.
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21
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Singh RK, Mahalingam K. In silico approach to identify non-synonymous SNPs in human obesity related gene, MC3R (melanocortin-3-receptor). Comput Biol Chem 2016; 67:122-130. [PMID: 28073065 DOI: 10.1016/j.compbiolchem.2016.12.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Revised: 11/19/2016] [Accepted: 12/20/2016] [Indexed: 10/20/2022]
Abstract
The melanocortin-3-receptor (MC3R) is a novel gene candidate for human obesity, which involved in controlling the energy homeostasis and food intake behavior. The main aim behind this work is to investigate the potentially deleterious non-synonymous single nucleotide polymorphisms (nsSNPs) in obesity related gene MC3R by using six computational tools viz., PolyPhen, I-Mutant, PROVEAN, SIFT, PANTHER and PhD-SNP. In our study, we predicted eight nsSNPs i.e., rs74315393 (Ile146Asn), rs368205448 (Asp121Tyr), rs143321797 (Phe45Ser), rs17847261 (Cys274Ser), rs144166442 (Pro257His), rs370533946 (Leu224Pro), rs371354428 (Pro72Leu) and rs373708098 (Gly249Ser) found to be potentially deleterious. The functional impact of three nsSNPs i.e., rs74315393, rs368205448 and rs143321797 have already been validated experimentally in the context of human obesity. Moreover, Homology modeling and structural analysis were carried out for already experimentally validated nsSNPs i.e., rs74315393, rs368205448 and rs143321797 to check the stability of predicted models. The mutant models showed higher energy and RMSD (Root mean square deviation) values. In addition, FTSite server predicted one nsSNP i.e., rs368205448 (Asp121Tyr) out of eight identified nsSNPs found in the MC3R protein binding site. Thus, the present computational study may suggest that predicted nsSNPs possibly be a better drug target and contribute to the treatment and better understanding of human obesity.
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Affiliation(s)
- Rajan Kumar Singh
- Department of Bio-Medical Sciences, School of Biosciences and Technology, VIT University, Vellore, 632014, Tamilnadu, India
| | - Kulandaivelu Mahalingam
- Department of Bio-Medical Sciences, School of Biosciences and Technology, VIT University, Vellore, 632014, Tamilnadu, India.
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Anandhakrishnan A, Korbonits M. Glucagon-like peptide 1 in the pathophysiology and pharmacotherapy of clinical obesity. World J Diabetes 2016; 7:572-598. [PMID: 28031776 PMCID: PMC5155232 DOI: 10.4239/wjd.v7.i20.572] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 09/26/2016] [Accepted: 10/18/2016] [Indexed: 02/05/2023] Open
Abstract
Though the pathophysiology of clinical obesity is undoubtedly multifaceted, several lines of clinical evidence implicate an important functional role for glucagon-like peptide 1 (GLP-1) signalling. Clinical studies assessing GLP-1 responses in normal weight and obese subjects suggest that weight gain may induce functional deficits in GLP-1 signalling that facilitates maintenance of the obesity phenotype. In addition, genetic studies implicate a possible role for altered GLP-1 signalling as a risk factor towards the development of obesity. As reductions in functional GLP-1 signalling seem to play a role in clinical obesity, the pharmacological replenishment seems a promising target for the medical management of obesity in clinical practice. GLP-1 analogue liraglutide at a high dose (3 mg/d) has shown promising results in achieving and maintaining greater weight loss in obese individuals compared to placebo control, and currently licensed anti-obesity medications. Generally well tolerated, provided that longer-term data in clinical practice supports the currently available evidence of superior short- and long-term weight loss efficacy, GLP-1 analogues provide promise towards achieving the successful, sustainable medical management of obesity that remains as yet, an unmet clinical need.
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23
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Aris IM, Tint MT, Teh AL, Holbrook JD, Quah PL, Chong MF, Lin X, Soh SE, Saw S, Kwek K, Godfrey KM, Gluckman PD, Chong YS, Lek N, Yap F, Lee YS. MC3R gene polymorphisms are associated with early childhood adiposity gain and infant appetite in an Asian population. Pediatr Obes 2016; 11:450-458. [PMID: 26663875 PMCID: PMC5111755 DOI: 10.1111/ijpo.12086] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/17/2015] [Accepted: 10/24/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND Polymorphic variants within human melanocortin-3 receptor gene (MC3R) gene have been associated with obesity. However, its influence on infancy and early childhood adiposity has not been reported before. OBJECTIVES We assessed associations between genotype at polymorphic sites within MC3R with early childhood adiposity and interaction with early childhood appetitive traits. METHODS We studied 1090 singletons in an Asian mother-offspring cohort genotyped for MC3R and in a subgroup (n = 422) who had completed Child Eating Behaviour Questionnaires (CEBQ) at 12 months. Children were followed from birth to 48 months, and up to 10 measurements of body mass index and five measures of triceps and subscapular skin-folds were obtained. RESULTS Independent of potential confounders, each additional MC3R minor allele copy was associated with greater body mass index standard deviation score [B{95% confidence interval}: 0.004 units/month {0.001,0.007}; p = 0.007], triceps [0.009 mm/month {0.001,0.02}; p = 0.021] and subscapular skin-fold [0.008 mm/month {0.002,0.01}; p = 0.011] gain velocity in the first 48 months. Each additional MC3R minor allele copy was also associated with increased odds of overweight [odds ratio {95% confidence interval}: 1.48{1.17-1.88}] and obesity [1.58{1.10-2.28}] in the first 48 months. Every additional copy of MC3R minor allele was positively associated with 'slowness-in-eating' appetitive trait [0.24{0.06,0.39}, p = 0.006]; however, the relationship between 'slowness-in-eating' with adiposity gain was not statistically significant. CONCLUSIONS Our findings support the role of MC3R genetic variants in adiposity gain during early childhood.
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Affiliation(s)
- I. M. Aris
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - M. T. Tint
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - A. L. Teh
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
| | - J. D. Holbrook
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
| | - P. L. Quah
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
| | - M. F.‐F. Chong
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - X. Lin
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
| | - S. E. Soh
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - S.‐M. Saw
- Saw Swee Hock School of Public HealthNational University of SingaporeSingapore
| | - K. Kwek
- Department of Maternal Fetal MedicineKK Women's and Children's HospitalSingapore
| | - K. M. Godfrey
- MRC Lifecourse Epidemiology Unit and NIHR Southampton Biomedical Research CentreUniversity of Southampton and University Hospital Southampton NHS Foundation TrustSouthamptonUK
| | - P. D. Gluckman
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
- Liggins InstituteUniversity of AucklandAucklandNew Zealand
| | - Y. S. Chong
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - N. Lek
- Department of PaediatricsKK Women's and Children's HospitalSingapore
| | - F. Yap
- Department of PaediatricsKK Women's and Children's HospitalSingapore
| | - Y. S. Lee
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
- Khoo Teck Puat‐National University Children's Medical InstituteNational University Health SystemSingapore
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24
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Yoshiuchi I. Evidence for natural selection at the melanocortin-3 receptor gene in European and African populations. Acta Diabetol 2016; 53:583-7. [PMID: 26909893 DOI: 10.1007/s00592-016-0846-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 02/04/2016] [Indexed: 10/22/2022]
Abstract
AIMS Obesity is increasing steadily in worldwide prevalence and is known to cause serious health problems in association with type 2 diabetes mellitus (T2DM), including hypertension, stroke, and cardiovascular diseases. According to the thrifty gene hypothesis, the natural selection of obesity-related genes is important during feast and famine because they control body weight and fat levels. Past human adaptations to environmental changes in food supply, lifestyle, and geography may have influenced the selection of genes associated with the metabolism of glucose, lipids, and energy. The melanocortin-3 receptor gene (MC3R) is associated with obesity, with MC3R-deficient mice showing increased fat mass. MC3R variations are also linked with childhood obesity and insulin resistance. Here, we aimed to uncover evidence of selection at MC3R. METHODS We performed a three-step method to detect selection at MC3R using HapMap population data. We used Wright's F statistics as a measure of population differentiation, the long-range haplotype test to identify extended haplotypes, and the integrated haplotype score (iHS) to detect selection at MC3R. RESULTS We observed high population differentiation between European and African populations at two MC3R childhood obesity- and insulin resistance-associated single-nucleotide polymorphisms (rs3746619 and rs3827103) using Wright's F statistics. The iHS revealed evidence of natural selection at MC3R. CONCLUSIONS These findings provide evidence for natural selection at MC3R. Further investigation is warranted into adaptive evolution at T2DM- and obesity-associated genes.
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Affiliation(s)
- Issei Yoshiuchi
- Departments of Genetics, Diabetes Mellitus, and Medicine, Yoshiuchi Medical Diabetes Institute, 2-16-41 Kamakurayama, Kamakura City, Kanagawa, 248-0031, Japan.
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25
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Mutations in Melanocortin-3 Receptor Gene and Human Obesity. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 140:97-129. [DOI: 10.1016/bs.pmbts.2016.01.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Jackson DS, Ramachandrappa S, Clark AJ, Chan LF. Melanocortin receptor accessory proteins in adrenal disease and obesity. Front Neurosci 2015; 9:213. [PMID: 26113808 PMCID: PMC4461818 DOI: 10.3389/fnins.2015.00213] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 05/28/2015] [Indexed: 12/02/2022] Open
Abstract
Melanocortin receptor accessory proteins (MRAPs) are regulators of the melanocortin receptor family. MRAP is an essential accessory factor for the functional expression of the MC2R/ACTH receptor. The importance of MRAP in adrenal gland physiology is demonstrated by the clinical condition familial glucocorticoid deficiency type 2. The role of its paralog melanocortin-2-receptor accessory protein 2 (MRAP2), which is predominantly expressed in the hypothalamus including the paraventricular nucleus, has recently been linked to mammalian obesity. Whole body deletion and targeted brain specific deletion of the Mrap2 gene result in severe obesity in mice. Interestingly, Mrap2 complete knockout (KO) mice have increased body weight without detectable changes to food intake or energy expenditure. Rare heterozygous variants of MRAP2 have been found in humans with severe, early-onset obesity. In vitro data have shown that Mrap2 interaction with the melanocortin-4-receptor (Mc4r) affects receptor signaling. However, the mechanism by which Mrap2 regulates body weight in vivo is not fully understood and differences between the phenotypes of Mrap2 and Mc4r KO mice may point toward Mc4r independent mechanisms.
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Affiliation(s)
- David S Jackson
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London London, UK
| | - Shwetha Ramachandrappa
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London London, UK
| | - Adrian J Clark
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London London, UK
| | - Li F Chan
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London London, UK
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27
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Forsberg SKG, Kierczak M, Ljungvall I, Merveille AC, Gouni V, Wiberg M, Lundgren Willesen J, Hanås S, Lequarré AS, Mejer Sørensen L, Tiret L, McEntee K, Seppälä E, Koch J, Battaille G, Lohi H, Fredholm M, Chetboul V, Häggström J, Carlborg Ö, Lindblad-Toh K, Höglund K. The Shepherds' Tale: A Genome-Wide Study across 9 Dog Breeds Implicates Two Loci in the Regulation of Fructosamine Serum Concentration in Belgian Shepherds. PLoS One 2015; 10:e0123173. [PMID: 25970163 PMCID: PMC4430432 DOI: 10.1371/journal.pone.0123173] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 02/10/2015] [Indexed: 01/24/2023] Open
Abstract
Diabetes mellitus is a serious health problem in both dogs and humans. Certain dog breeds show high prevalence of the disease, whereas other breeds are at low risk. Fructosamine and glycated haemoglobin (HbA1c) are two major biomarkers of glycaemia, where serum concentrations reflect glucose turnover over the past few weeks to months. In this study, we searched for genetic factors influencing variation in serum fructosamine concentration in healthy dogs using data from nine dog breeds. Considering all breeds together, we did not find any genome-wide significant associations to fructosamine serum concentration. However, by performing breed-specific analyses we revealed an association on chromosome 3 (pcorrected ≈ 1:68 × 10-6) in Belgian shepherd dogs of the Malinois subtype. The associated region and its close neighbourhood harbours interesting candidate genes such as LETM1 and GAPDH that are important in glucose metabolism and have previously been implicated in the aetiology of diabetes mellitus. To further explore the genetics of this breed specificity, we screened the genome for reduced heterozygosity stretches private to the Belgian shepherd breed. This revealed a region with reduced heterozygosity that shows a statistically significant interaction (p = 0.025) with the association region on chromosome 3. This region also harbours some interesting candidate genes and regulatory regions but the exact mechanisms underlying the interaction are still unknown. Nevertheless, this finding provides a plausible explanation for breed-specific genetic effects for complex traits in dogs. Shepherd breeds are at low risk of developing diabetes mellitus. The findings in Belgian shepherds could be connected to a protective mechanism against the disease. Further insight into the regulation of glucose metabolism could improve diagnostic and therapeutic methods for diabetes mellitus.
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Affiliation(s)
- Simon K. G. Forsberg
- Computational Genetics Section, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
- * E-mail: (SKGF), (MK), (KH)
| | - Marcin Kierczak
- Computational Genetics Section, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Science for Life Laboratory & Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- * E-mail: (SKGF), (MK), (KH)
| | - Ingrid Ljungvall
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anne-Christine Merveille
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Liège, Liège Belgium
| | - Vassiliki Gouni
- Université Paris-Est, Ecole Nationale Vétérinaire d’Alfort, Unité de Cardiologie d’Alfort (UCA), Centre Hospitalier Universitaire Vétérinaire d’Alfort, Maisons-Alfort, France
| | - Maria Wiberg
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Jakob Lundgren Willesen
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sofia Hanås
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Evidensia, Animal Clinic Västerås, Västerås, Sweden
| | - Anne-Sophie Lequarré
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Liège, Liège Belgium
| | - Louise Mejer Sørensen
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Laurent Tiret
- INRA, UMR955 de Génétique Fonctionnelle et Médicale, Maisons-Alfort, France
- Université Paris-Est Créteil, CNM project, Ecole Nationale Vétérinaire d’Alfort, Maisons-Alfort, France
| | - Kathleen McEntee
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Liège, Liège Belgium
- Laboratory of Physiology, Faculty of Medicine, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Eija Seppälä
- Department of Veterinary Biosciences, Research Program in Molecular Neurology Research Programs Unit, University of Helsinki, Helsinki, Finland
- Folkhälsan Institute of Genetics, Helsinki, Finland
- Department of Medical Genetics, University of Helsinki, Helsinki, Finland
| | - Jørgen Koch
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Géraldine Battaille
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Liège, Liège Belgium
| | - Hannes Lohi
- Department of Veterinary Biosciences, Research Program in Molecular Neurology Research Programs Unit, University of Helsinki, Helsinki, Finland
- Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Merete Fredholm
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Valerie Chetboul
- Université Paris-Est, Ecole Nationale Vétérinaire d’Alfort, Unité de Cardiologie d’Alfort (UCA), Centre Hospitalier Universitaire Vétérinaire d’Alfort, Maisons-Alfort, France
- INSERM, U955, Equipe 03, Créteil, France
| | - Jens Häggström
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Örjan Carlborg
- Computational Genetics Section, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Kerstin Lindblad-Toh
- Science for Life Laboratory & Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Katja Höglund
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
- * E-mail: (SKGF), (MK), (KH)
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28
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Rodrigues AR, Almeida H, Gouveia AM. Intracellular signaling mechanisms of the melanocortin receptors: current state of the art. Cell Mol Life Sci 2015; 72:1331-45. [PMID: 25504085 PMCID: PMC11113477 DOI: 10.1007/s00018-014-1800-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 11/07/2014] [Accepted: 12/01/2014] [Indexed: 12/28/2022]
Abstract
The melanocortin system is composed by the agonists adrenocorticotropic hormone and α, β and γ-melanocyte-stimulating hormone, and two naturally occurring antagonists, agouti and agouti-related protein. These ligands act by interaction with a family of five melanocortin receptors (MCRs), assisted by MCRs accessory proteins (MRAPs). MCRs stimulation activates different signaling pathways that mediate a diverse array of physiological processes, including pigmentation, energy metabolism, inflammation and exocrine secretion. This review focuses on the regulatory mechanisms of MCRs signaling, highlighting the differences among the five receptors. MCRs signal through G-dependent and independent mechanisms and their functional coupling to agonists at the cell surface is regulated by interacting proteins, namely MRAPs and β-arrestins. The knowledge of the distinct modulation pattern of MCRs signaling and function may be helpful for the future design of novel drugs able to combine specificity, safety and effectiveness in the course of their therapeutic use.
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Affiliation(s)
- Adriana R Rodrigues
- Department of Experimental Biology, Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal,
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29
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Yazdi FT, Clee SM, Meyre D. Obesity genetics in mouse and human: back and forth, and back again. PeerJ 2015; 3:e856. [PMID: 25825681 PMCID: PMC4375971 DOI: 10.7717/peerj.856] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 03/05/2015] [Indexed: 12/19/2022] Open
Abstract
Obesity is a major public health concern. This condition results from a constant and complex interplay between predisposing genes and environmental stimuli. Current attempts to manage obesity have been moderately effective and a better understanding of the etiology of obesity is required for the development of more successful and personalized prevention and treatment options. To that effect, mouse models have been an essential tool in expanding our understanding of obesity, due to the availability of their complete genome sequence, genetically identified and defined strains, various tools for genetic manipulation and the accessibility of target tissues for obesity that are not easily attainable from humans. Our knowledge of monogenic obesity in humans greatly benefited from the mouse obesity genetics field. Genes underlying highly penetrant forms of monogenic obesity are part of the leptin-melanocortin pathway in the hypothalamus. Recently, hypothesis-generating genome-wide association studies for polygenic obesity traits in humans have led to the identification of 119 common gene variants with modest effect, most of them having an unknown function. These discoveries have led to novel animal models and have illuminated new biologic pathways. Integrated mouse-human genetic approaches have firmly established new obesity candidate genes. Innovative strategies recently developed by scientists are described in this review to accelerate the identification of causal genes and deepen our understanding of obesity etiology. An exhaustive dissection of the molecular roots of obesity may ultimately help to tackle the growing obesity epidemic worldwide.
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Affiliation(s)
- Fereshteh T. Yazdi
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada
| | - Susanne M. Clee
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - David Meyre
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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30
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Li Z, Huang Y, Li H, Hu J, Liu X, Jiang T, Sun G, Tang A, Sun X, Qian W, Zeng Y, Xie J, Zhao W, Xu Y, He T, Dong C, Liu Q, Mou L, Lu J, Lin Z, Wu S, Gao S, Guo G, Feng Q, Li Y, Zhang X, Wang J, Yang H, Wang J, Xiong C, Cai Z, Gui Y. Excess of rare variants in genes that are key epigenetic regulators of spermatogenesis in the patients with non-obstructive azoospermia. Sci Rep 2015; 5:8785. [PMID: 25739334 PMCID: PMC4350091 DOI: 10.1038/srep08785] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 02/04/2015] [Indexed: 01/08/2023] Open
Abstract
Non-obstructive azoospermia (NOA), a severe form of male infertility, is often suspected to be linked to currently undefined genetic abnormalities. To explore the genetic basis of this condition, we successfully sequenced ~650 infertility-related genes in 757 NOA patients and 709 fertile males. We evaluated the contributions of rare variants to the etiology of NOA by identifying individual genes showing nominal associations and testing the genetic burden of a given biological process as a whole. We found a significant excess of rare, non-silent variants in genes that are key epigenetic regulators of spermatogenesis, such as BRWD1, DNMT1, DNMT3B, RNF17, UBR2, USP1 and USP26, in NOA patients (P = 5.5 × 10(-7)), corresponding to a carrier frequency of 22.5% of patients and 13.7% of controls (P = 1.4 × 10(-5)). An accumulation of low-frequency variants was also identified in additional epigenetic genes (BRDT and MTHFR). Our study suggested the potential associations of genetic defects in genes that are epigenetic regulators with spermatogenic failure in human.
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Affiliation(s)
- Zesong Li
- 1] Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen 518036, China [2] Shenzhen Key Laboratory of Genitourinary Cancer, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China [3] National-Regional Engineering Laboratory for Clinical Application of Cancer Genomics, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China
| | - Yi Huang
- 1] Shenzhen Key Laboratory of Genitourinary Cancer, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China [2] National-Regional Engineering Laboratory for Clinical Application of Cancer Genomics, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China
| | - Honggang Li
- Family Planning Research Institute/The Center of Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | | | - Xiao Liu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Tao Jiang
- BGI-Shenzhen, Shenzhen 518083, China
| | | | - Aifa Tang
- 1] Shenzhen Key Laboratory of Genitourinary Cancer, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China [2] National-Regional Engineering Laboratory for Clinical Application of Cancer Genomics, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China
| | - Xiaojuan Sun
- 1] Shenzhen Key Laboratory of Genitourinary Cancer, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China [2] National-Regional Engineering Laboratory for Clinical Application of Cancer Genomics, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China
| | - Weiping Qian
- The Center of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen 518036, China
| | - Yong Zeng
- Shenzhen Key Laboratory of Reproductive Immunology for Peri-implantation, Shenzhen Zhongshan Urology Hospital, Shenzhen 518045, China
| | - Jun Xie
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen 518036, China
| | - Wei Zhao
- BGI-Shenzhen, Shenzhen 518083, China
| | - Yu Xu
- BGI-Shenzhen, Shenzhen 518083, China
| | | | | | - Qunlong Liu
- The Center of Reproductive Medicine, Peking University Shenzhen Hospital, Shenzhen 518036, China
| | - Lisha Mou
- 1] Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen 518036, China [2] Shenzhen Key Laboratory of Genitourinary Cancer, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China [3] National-Regional Engineering Laboratory for Clinical Application of Cancer Genomics, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China
| | - Jingxiao Lu
- 1] Shenzhen Key Laboratory of Genitourinary Cancer, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China [2] National-Regional Engineering Laboratory for Clinical Application of Cancer Genomics, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China
| | - Zheguang Lin
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen 518036, China
| | - Song Wu
- 1] Shenzhen Key Laboratory of Genitourinary Cancer, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China [2] National-Regional Engineering Laboratory for Clinical Application of Cancer Genomics, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China
| | | | | | | | | | | | - Jun Wang
- BGI-Shenzhen, Shenzhen 518083, China
| | | | - Jian Wang
- BGI-Shenzhen, Shenzhen 518083, China
| | - Chengliang Xiong
- Family Planning Research Institute/The Center of Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zhiming Cai
- 1] Shenzhen Key Laboratory of Genitourinary Cancer, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China [2] National-Regional Engineering Laboratory for Clinical Application of Cancer Genomics, Shenzhen Second People's Hospital, the First Affiliated Hospital of Shenzhen University, Shenzhen 518035, China
| | - Yaoting Gui
- Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen 518036, China
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Yang F, Huang H, Tao YX. Biased signaling in naturally occurring mutations in human melanocortin-3 receptor gene. Int J Biol Sci 2015; 11:423-33. [PMID: 25798062 PMCID: PMC4366641 DOI: 10.7150/ijbs.11032] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 01/21/2015] [Indexed: 12/17/2022] Open
Abstract
The melanocortin-3 receptor (MC3R) is primarily expressed in the hypothalamus and plays an important role in the regulation of energy homeostasis. Recently, some studies demonstrated that MC3R also signals through mitogen-activated protein kinases (MAPKs), especially extracellular signal-regulated kinases 1 and 2 (ERK1/2). ERK1/2 signaling is known to alter gene expression, potentially contributing to the prolonged action of melanocortins on energy homeostasis regulation. In the present study, we performed detailed functional studies on 8 novel naturally occurring MC3R mutations recently reported, and the effects of endogenous MC3R agonist, α-melanocyte stimulating hormone (MSH), on ERK1/2 signaling on all 22 naturally occurring MC3R mutations reported to date. We found that mutants D158Y and L299V were potential pathogenic causes to obesity. Four residues, F82, D158, L249 and L299, played critical roles in different aspects of MC3R function. α-MSH exhibited balanced activity in Gs-cAMP and ERK1/2 signaling pathways in 15 of the 22 mutant MC3Rs. The other 7 mutant MC3Rs were biased to either one of the signaling pathways. In summary, we provided novel data about the structure-function relationship of MC3R, identifying residues important for receptor function. We also demonstrated that some mutations exhibited biased signaling, preferentially activating one intracellular signaling pathway, adding a new layer of complexity to MC3R pharmacology.
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Affiliation(s)
- Fan Yang
- 1. Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA. ; 2. Current address: College of Life Sciences, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, China
| | - Hui Huang
- 1. Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
| | - Ya-Xiong Tao
- 1. Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
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Park J, Sharma N, Cutting GR. Melanocortin 3 receptor has a 5' exon that directs translation of apically localized protein from the second in-frame ATG. Mol Endocrinol 2014; 28:1547-57. [PMID: 25051171 DOI: 10.1210/me.2014-1105] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Melanocortin-3 receptor (MC3R) is a canonical MSH receptor that plays an essential role in energy homeostasis. Variants in MC3R have been implicated in obesity in humans and mice. However, interpretation of the functional consequences of these variants is challenging because the translational start site of MC3R is unclear. Using 5' rapid amplification of cDNA ends, we discovered a novel upstream exon that extends the length of the 5' untranslated region (UTR) in MC3R without changing the open-reading frame. The full-length 5' UTR directs utilization of an evolutionarily conserved second in-frame ATG as the primary translation start site. MC3R synthesized from the second ATG is localized to apical membranes of polarized Madin-Darby canine kidney cells, consistent with its function as a cell surface mediator of melanocortin signaling. Expression of MC3R causes relocalization of melanocortin receptor accessory protein 2, an accessory factor for melanocortin-2 receptor, to the apical membrane, coincident with the location of MC3R. In contrast, protein synthesized from MC3R cDNAs lacking the 5' UTR displayed diffuse cytosolic distribution and has no effect on the distribution of melanocortin receptor accessory protein 2. Our findings demonstrate that a previously unannotated 5' exon directs translation of MC3R protein that localizes to apical membranes of polarized cells. Together, our work provides insight on the structure of human MC3R and reveals a new pathway for regulation of energy metabolism.
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Affiliation(s)
- Jeenah Park
- McKusick-Nathans Institute of Genetic Medicine (J.P., N.S., G.R.C.), Johns Hopkins University, Baltimore, Maryland 21218; and Department of Pediatrics (G.R.C.), Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-3914
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Tao YX, Huang H. Ipsen 5i is a Novel Potent Pharmacoperone for Intracellularly Retained Melanocortin-4 Receptor Mutants. Front Endocrinol (Lausanne) 2014; 5:131. [PMID: 25136332 PMCID: PMC4120685 DOI: 10.3389/fendo.2014.00131] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 07/20/2014] [Indexed: 11/13/2022] Open
Abstract
Inactivating mutations of the melanocortin-4 receptor (MC4R) cause early-onset severe obesity in humans. Comprehensive functional studies show that most of the inactivating mutants of the MC4R are retained intracellularly. In the present study, we investigated whether a small molecule inverse agonist of the MC4R, Ipsen 5i, could act as a pharmacoperone and correct the cell surface expression and function of intracellularly retained mutant MC4Rs using multiple cell lines, including HEK293 and two neuronal cell lines. We showed that Ipsen 5i rescued the cell surface expression of all 11 intracellularly retained mutant MC4Rs studied herein in at least one cell line. Ipsen 5i functionally rescued seven mutants in all cell lines used. One mutant (Y157S) was functionally rescued in HEK293 cells but not in the two neuronal cell lines. Ipsen 5i increased cell surface expression of three mutants (S58C, G98R, and F261S) but did not affect signaling. Ipsen 5i had no effect on mutant MC4Rs with other defects (Δ88-92, D90N, I102S) or no defect (N274S). It also did not affect trafficking of a misrouted MC3R mutant (I335S). Cell impermeable peptide ligands of the MC4R or cell permeable small molecule ligand of δ opioid receptor could not rescue misrouted mutant MC4R. In summary, we demonstrated that Ipsen 5i was a novel potent pharmacoperone of the MC4R, correcting trafficking and signaling of a significant portion (73%) of intracellularly retained mutants. Additional studies are needed to demonstrate its in vivo efficacy.
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University , Auburn, AL , USA
| | - Hui Huang
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University , Auburn, AL , USA
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Abstract
PURPOSE OF REVIEW Common obesity is widely regarded as a complex, multifactorial trait influenced by the 'obesogenic' environment, sedentary behavior, and genetic susceptibility contributed by common and rare genetic variants. This review describes the recent advances in understanding the role of genetics in obesity. RECENT FINDINGS New susceptibility loci and genetic variants are being uncovered, but the collective effect is relatively small and could not explain most of the BMI heritability. Yet-to-be identified common and rare variants, epistasis, and heritable epigenetic changes may account for part of the 'missing heritability'. Evidence is emerging about the role of epigenetics in determining obesity susceptibility, mediating developmental plasticity, which confers obesity risk from early life experiences. Genetic prediction scores derived from selected genetic variants, and also differential DNA methylation levels and methylation scores, have been shown to correlate with measures of obesity and response to weight loss intervention. Genetic variants, which confer susceptibility to obesity-related morbidities like nonalcoholic fatty liver disease, were also discovered recently. SUMMARY We can expect discovery of more rare genetic variants with the advent of whole exome and genome sequencing, and also greater understanding of epigenetic mechanisms by which environment influences genetic expression and which mediate the gene-environment interaction.
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Three novel SNPs in the coding region of the bovine MC3R gene and their associations with growth traits. Biochem Genet 2013; 52:116-24. [PMID: 24233436 DOI: 10.1007/s10528-013-9632-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 07/23/2013] [Indexed: 12/30/2022]
Abstract
The involvement of melanocortin-3 receptor (MC3R) is well recognized in the regulation of feeding efficiency, body weight, and energy homeostasis. The objective of this study was to investigate the associations between MC3R gene polymorphisms and growth traits. Three novel SNPs (c.24C→T, c.220T→A, c.734G→C) and five haplotypes were identified in 234 Xiangxi cattle. The associations between MC3R gene polymorphisms and growth traits indicated that the individuals with TT and AT genotypes maintained higher body weight than those with the AA genotype at the c.220T→A locus (P < 0.05). The animals with GG and CG genotypes had higher heart girth and body weight than those with the CC genotype at c.734G→C (P < 0.05). The animals with H3H3 and H2H3 haplotype combinations had higher body weight than those with other haplotype combinations (P < 0.05). The results suggest that these SNPs in the MC3R gene might be useful genetic markers for marker-assisted selection and cattle breeding.
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Common polymorphism (81Val>Ile) and rare mutations (257Arg>Ser and 335Ile>Ser) of the MC3R gene in obese Polish children and adolescents. Mol Biol Rep 2013; 40:6893-8. [PMID: 24142065 PMCID: PMC3835951 DOI: 10.1007/s11033-013-2808-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 10/12/2013] [Indexed: 01/11/2023]
Abstract
The predisposing role to human obesity of the MC3R gene polymorphism is controversial. In this report we present the first study focused on the search for the MC3R polymorphism in the Polish population. Altogether 257 obese children and adolescents (RBMI>120) and 94 adults, who were never obese or overweight (BMI<25), were studied. For all subjects the entire coding sequence was analyzed by direct DNA sequencing. One common polymorphism (81Val>Ile) and two rare mutations (257Arg>Ser and 335Ile>Ser) were identified. The common polymorphism was widely distributed in the obese and control cohorts, while the mutations were identified in four obese subjects only. In case of the 335Ile>Ser substitution a three-generation family, consisting of 20 members, was also analyzed. It was found that all carriers of the 335Ser mutation were obese, but among non-carriers obese subjects also were found. Our study suggests that the predisposing effect to obesity of the 81Ile polymorphic variant is rather unlikely. With regard to the studied rare mutations we suggest that the 335Ser allele may have a small predisposing effect.
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Zegers D, Beckers S, Hendrickx R, Van Camp JK, Van Hoorenbeeck K, Desager KN, Massa G, Van Gaal LF, Van Hul W. Prevalence of rare MC3R variants in obese cases and lean controls. Endocrine 2013; 44:386-90. [PMID: 23264184 DOI: 10.1007/s12020-012-9862-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 12/12/2012] [Indexed: 01/13/2023]
Abstract
The role of mutations in the melanocortin-3 receptor (MC3R) gene, which is implicated in the regulation of energy homeostasis, is still under debate. Animal studies have clearly proven that, together with the melanocortin-4 receptor (MC4R), the MC3R is a critical receptor for melanocortin peptides within the leptin-melanocortin signaling cascade. However, as several mutations have been found in lean individuals and not all mutations seem to cause receptor dysfunction, results from mutation screens in obese humans remain controversial. In the present study, we screened for rare variants in the MC3R gene of obese children and lean controls to assess the prevalence of MC3R mutations in the Belgian population. We screened 249 severely overweight and obese children and adolescents and 239 lean adults for mutations in the coding region of MC3R. Mutation screening was performed by high resolution melting curve analysis and direct sequencing. We identified four non-synonymous coding variations in the obese population, all of which had been reported previously. In addition, we also found four novel rare MC3R variants in the lean control population, suggesting that not all MC3R mutations are disease-causing. Overall, the total prevalence of rare MC3R variants was 1 % in Belgian obese children and adolescents compared to 1.02 % in lean controls. Ultimately, cosegregation studies combined with comprehensive functional analysis is required to determine the potential pathogenic role of rare MC3R variants in causing human obesity.
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Affiliation(s)
- Doreen Zegers
- Department of Medical Genetics, University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium
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Gerhard GS, Chu X, Wood GC, Gerhard GM, Benotti P, Petrick AT, Gabrielsen J, Strodel WE, Still CD, Argyropoulos G. Next-generation sequence analysis of genes associated with obesity and nonalcoholic fatty liver disease-related cirrhosis in extreme obesity. Hum Hered 2013; 75:144-51. [PMID: 24081230 DOI: 10.1159/000351719] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES Genome-wide association studies (GWAS) have led to the identification of single nucleotide polymorphisms in or near several loci that are associated with the risk of obesity and nonalcoholic fatty liver disease (NAFLD). We hypothesized that missense variants in GWAS and related candidate genes may underlie cases of extreme obesity and NAFLD-related cirrhosis, an extreme manifestation of NAFLD. METHODS We performed whole-exome sequencing on 6 Caucasian patients with extreme obesity [mean body mass index (BMI) 84.4] and 4 obese Caucasian patients (mean BMI 57.0) with NAFLD-related cirrhosis. RESULTS Sequence analysis was performed on 24 replicated GWAS and selected candidate obesity genes and 5 loci associated with NAFLD. No missense variants were identified in 19 of the 29 genes analyzed, although all patients carried at least 2 missense variants in the remaining genes without excess homozygosity. One patient with extreme obesity carried 2 novel damaging mutations in BBS1 and was homozygous for benign and damaging MC3R variants. In addition, 1 patient with NAFLD-related cirrhosis was compound heterozygous for rare damaging mutations in PNPLA3. CONCLUSIONS These results indicate that analyzing candidate loci previously identified by GWAS analyses using whole-exome sequencing is an effective strategy to identify potentially causative missense variants underlying extreme obesity and NAFLD-related cirrhosis.
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Affiliation(s)
- Glenn S Gerhard
- Geisinger Obesity Research Institute, Geisinger Clinic, Danville, Pa., USA
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39
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Girardet C, Butler AA. Neural melanocortin receptors in obesity and related metabolic disorders. Biochim Biophys Acta Mol Basis Dis 2013; 1842:482-94. [PMID: 23680515 DOI: 10.1016/j.bbadis.2013.05.004] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/16/2013] [Accepted: 05/03/2013] [Indexed: 12/11/2022]
Abstract
Obesity is a global health issue, as it is associated with increased risk of developing chronic conditions associated with disorders of metabolism such as type 2 diabetes and cardiovascular disease. A better understanding of how excessive fat accumulation develops and causes diseases of the metabolic syndrome is urgently needed. The hypothalamic melanocortin system is an important point of convergence connecting signals of metabolic status with the neural circuitry that governs appetite and the autonomic and neuroendocrine system controling metabolism. This system has a critical role in the defense of body weight and maintenance of homeostasis. Two neural melanocortin receptors, melanocortin 3 and 4 receptors (MC3R and MC4R), play crucial roles in the regulation of energy balance. Mutations in the MC4R gene are the most common cause of monogenic obesity in humans, and a large literature indicates a role in regulating both energy intake through the control of satiety and energy expenditure. In contrast, MC3Rs have a more subtle role in energy homeostasis. Results from our lab indicate an important role for MC3Rs in synchronizing rhythms in foraging behavior with caloric cues and maintaining metabolic homeostasis during periods of nutrient scarcity. However, while deletion of the Mc3r gene in mice alters nutrient partitioning to favor accumulation of fat mass no obvious role for MC3R haploinsufficiency in human obesity has been reported. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease.
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MESH Headings
- Animals
- Body Weight/genetics
- Cardiovascular Diseases/complications
- Cardiovascular Diseases/metabolism
- Cardiovascular Diseases/pathology
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Humans
- Metabolic Diseases/genetics
- Metabolic Diseases/metabolism
- Metabolic Diseases/pathology
- Mice
- Obesity/complications
- Obesity/genetics
- Obesity/metabolism
- Obesity/pathology
- Receptor, Melanocortin, Type 3/genetics
- Receptor, Melanocortin, Type 3/metabolism
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
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Affiliation(s)
- Clemence Girardet
- Department of Metabolism and Aging, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Andrew A Butler
- Department of Metabolism and Aging, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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Ramachandrappa S, Gorrigan RJ, Clark AJL, Chan LF. The melanocortin receptors and their accessory proteins. Front Endocrinol (Lausanne) 2013; 4:9. [PMID: 23404466 PMCID: PMC3567503 DOI: 10.3389/fendo.2013.00009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 01/25/2013] [Indexed: 12/26/2022] Open
Abstract
The five melanocortin receptors (MCRs) named MC1R-MC5R have diverse physiological roles encompassing pigmentation, steroidogenesis, energy homeostasis and feeding behavior as well as exocrine function. Since their identification almost 20 years ago much has been learnt about these receptors. As well as interacting with their endogenous ligands the melanocortin peptides, there is now a growing list of important peptides that can modulate the way these receptors signal, acting as agonists, antagonists, and inverse agonists. The discovery of melanocortin 2 receptor accessory proteins as a novel accessory factor to the MCRs provides further insight into the regulation of these important G protein-coupled receptor.
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Affiliation(s)
| | | | | | - Li F. Chan
- *Correspondence: Li F. Chan, Centre for Endocrinology, William Harvey Research Institute, Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Charterhouse Square, London EC1M 6BQ, UK. e-mail:
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Begriche K, Girardet C, McDonald P, Butler AA. Melanocortin-3 receptors and metabolic homeostasis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 114:109-46. [PMID: 23317784 DOI: 10.1016/b978-0-12-386933-3.00004-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Attenuated activity of the central nervous melanocortin system causes obesity and insulin resistance. Obese rodents treated with melanocortins exhibit improvements in obesity and metabolic homeostasis that are not mutually dependent, suggesting metabolic actions that are independent of weight changes. These responses are generally thought to involve G-protein-coupled receptors expressed in the brain. Melanocortin-4 receptors (MC4Rs) regulate satiety and autonomic nervous system and thyroid function. MC3Rs are expressed in hypothalamic and limbic regions involved in controlling ingestive behaviors and autonomic function. Mc3r-/- mice exhibit increased adiposity and an accelerated diet-induced obesity. While this phenotype is not dependent on hyperphagia, data on the regulation of food intake by MC3Rs are inconsistent. Recent investigations by our laboratory suggest a unique combination of behavioral and metabolic disorders in Mc3r-/- mice. MC3Rs are critical for the expression of the anticipatory response and metabolic homeostasis when food intake occurs outside the normal voluntary rhythms driven by photoperiod. Using a Cre-Lox strategy, we can now investigate MC3Rs expressed in different brain regions and organ systems in the periphery. While focusing on the functions of neural MC3Rs, early results suggest an additional layer of complexity with central and peripheral MC3Rs involved in the defense of body weight.
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Affiliation(s)
- Karima Begriche
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, Florida, USA
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Tao YX, Yuan ZH, Xie J. G Protein-Coupled Receptors as Regulators of Energy Homeostasis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 114:1-43. [DOI: 10.1016/b978-0-12-386933-3.00001-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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43
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Lee YS. Melanocortin 3 receptor gene and melanocortin 4 receptor gene mutations: the Asian Perspective. Diabetes Metab Res Rev 2012; 28 Suppl 2:26-31. [PMID: 23280863 DOI: 10.1002/dmrr.2351] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Melanocortin 4 receptor (MC4R) deficiency resulting from disruption of one or both MC4R alleles represents the commonest monogenic form of human obesity to date. Human MC4R deficiency was reported to affect 4 and 5.8% of severely obese French and British populations respectively. However, studies elsewhere reported low incidence of MC4R mutations in their obese populations. The significance of MC4R mutations in Asian obese populations has not been adequately examined, though small studies in Japan, China, and Singapore reported few or no pathogenic mutations, suggesting a low prevalence in this part of the world. There were also few common mutations described across populations, suggesting a relative lack of founder effect. The pathogenic role of melanocortin 3 receptor gene (MC3R) mutations in human obesity is not as well described and accepted as MC4R mutations, though it is gradually gaining ground. Two common single nucleotide polymorphisms Thr6Lys and Val81Ile within the coding region were associated with higher body fat and leptin levels in obese children, supported by impaired signaling activity in vitro. There were also reports of missense mutations enriched in obese populations. While MC3R mutations are unlikely to result in an autosomal dominant form of monogenic obesity given the lack of strong co-segregation in family studies, the studies so far provided evidence that MC3R can be one of the genes which contributes to increased adiposity, and exert an effect on the human phenotype.
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Affiliation(s)
- Yung Seng Lee
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, Singapore.
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44
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Kraja AT, Borecki IB, Tsai MY, Ordovas JM, Hopkins PN, Lai CQ, Frazier-Wood AC, Straka RJ, Hixson JE, Province MA, Arnett DK. Genetic analysis of 16 NMR-lipoprotein fractions in humans, the GOLDN study. Lipids 2012. [PMID: 23192668 DOI: 10.1007/s11745-012-3740-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Sixteen nuclear magnetic resonance (NMR) spectroscopy lipoprotein measurements of more than 1,000 subjects of GOLDN study, at fasting and at 3.5 and 6 h after a postprandial fat (PPL) challenge at visits 2 and 4, before and after a 3 weeks Fenofibrate (FF) treatment, were included in 6 time-independent multivariate factor analyses. Their top 1,541 unique SNPs were assessed for association with GOLDN NMR-particles and classical lipids. Several SNPs with -log₁₀ p > 7.3 and MAF ≥ 0.10, mostly intergenic associated with NMR-single traits near genes FAM84B (8q24.21), CRIPT (2p21), ACOXL (2q13), BCL2L11 (2q13), PCDH10 (4q28.3), NXPH1 (7p22), and SLC24A4 (14q32.12) in association with NMR-LDLs; HOMER1 (5q14.2), KIT (4q11-q12), VSNL1 (2p24.3), QPRT (16p11.2), SYNPR (3p14.2), NXPH1 (7p22), NELL1 (11p15.1), and RUNX3 (1p36) with NMR-HDLs; and DOK5-CBLN4-MC3R (20q13), NELL1 (11p15.1), STXBP6 (14q12), APOB (2p24-p23), GPR133 (12q24.33), FAM84B (8q24.21) and NR5A2 (1q32.1) in association with NMR-VLDLs particles. NMR single traits associations produced 75 % of 114 significant candidates, 7 % belonged to classical lipids and 18 % overlapped, and 16 % matched for time of discovery between NMR- and classical traits. Five proxy genes, (ACOXL, FAM84B, NXPH1, STK40 and VAPA) showed pleiotropic effects. While tagged for significant associations in our study and with some extra evidence from the literature, candidates as CBNL4, FAM84B, NXPH1, SLC24A4 remain unclear for their functional relation to lipid metabolism. Although GOLDN study is one of the largest in studying PPL and FF treatment effects, the relatively small samples (over 700-1,000 subjects) in association tests appeals for a replication of such a study. Thus, further investigation is needed.
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Affiliation(s)
- Aldi T Kraja
- Division of Statistical Genomics, Washington University School of Medicine, 4444 Forest Park Ave, Campus Box 8506, St. Louis, MO 63108, USA.
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45
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Yang F, Tao YX. Functional characterization of nine novel naturally occurring human melanocortin-3 receptor mutations. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1752-61. [PMID: 22884546 DOI: 10.1016/j.bbadis.2012.07.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Revised: 07/12/2012] [Accepted: 07/27/2012] [Indexed: 12/20/2022]
Abstract
The melanocortin-3 receptor (MC3R) is a member of family A rhodopsin-like G protein-coupled receptors. Mouse genetic studies suggested that MC3R and the related MC4R are non-redundant regulators of energy homeostasis. Lack of Mc3r leads to higher feed efficiency and fat mass. However, until now only a few MC3R mutations have been identified in humans and the role of MC3R in the pathogenesis of obesity was unclear. In the present study, we performed detailed functional studies on nine naturally occurring MC3R mutations recently reported. We found that all nine mutants had decreased cell surface expression. A260V, M275T, and L297V had decreased total expression whereas the other six mutants had normal total expression. Mutants S69C and T280S exhibited significant defects in ligand binding and signaling. The dramatic defects of T280S might be partially caused by decreased cell surface expression. In addition, we found mutants M134I and M275T had decreased maximal binding but displayed similar signaling properties as wild-type MC3R. All the other mutants had normal binding and signaling activities. Co-expression studies showed that all mutants except L297V did not affect wild-type MC3R signaling. Multiple mutations at T280 demonstrated the necessity of Thr for cell surface expression, ligand binding, and signaling. In summary, we provided detailed data of these novel human MC3R mutations leading to a better understanding of structure-function relationship of MC3R and the role of MC3R mutation in obesity.
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Affiliation(s)
- Fan Yang
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA
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Begriche K, Marston OJ, Rossi J, Burke LK, McDonald P, Heisler LK, Butler AA. Melanocortin-3 receptors are involved in adaptation to restricted feeding. GENES, BRAIN, AND BEHAVIOR 2012; 11:291-302. [PMID: 22353545 PMCID: PMC3319531 DOI: 10.1111/j.1601-183x.2012.00766.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 01/09/2012] [Accepted: 01/12/2012] [Indexed: 11/29/2022]
Abstract
The central nervous melanocortin system forms a neural network that maintains energy homeostasis. Actions involving neural melanocortin-3 receptors (MC3Rs) regulate the expression rhythms in ingestive behaviors and metabolism anticipating nutrient intake. Here, we characterized the response of Mc3r knockout (Mc3r(-/-)) and wild type (WT) mice to a restricted feeding (RF) schedule where food access was limited to a 4-h period mid light cycle using a mechanical barrier. Mc3r(-/-) mice adapted poorly to the food restriction schedule. Anticipatory activity and the initial bout of intense feeding activity associated with granting food access were attenuated in Mc3r(-/-) mice, resulting in increased weight loss relative to controls. To investigate whether activity in specific hypothalamic nuclei contribute to the Mc3r(-/-) phenotype observed, we assessed hypothalamic FOS-immunoreactivity (FOS-IR) associated with food restriction. Food access markedly increased FOS-IR in the dorsomedial hypothalamus (DMH), but not in the suprachiasmatic or ventromedial hypothalamic nuclei (SCN and VMN, respectively) compared to ad libitum fed mice. Mc3r(-/-) mice displayed a significant reduction in FOS-IR in the DMH during feeding. Analysis of MC3R signaling in vitro indicated dose-dependent stimulation of the extracellular signal-regulated kinase (ERK) pathway by the MC3R agonist d-Trp(8)-γMSH. Treatment of WT mice with d-Trp(8)-γMSH administered intracerebroventricularly increased the number of pERK neurons 1.7-fold in the DMH. These observations provide further support for the involvement of the MC3Rs in regulating adaptation to food restriction. Moreover, MC3Rs may modulate the activity of neurons in the DMH, a region previously linked to the expression of the anticipatory response to RF.
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Affiliation(s)
- K Begriche
- Department of Metabolism and Aging, The Scripps Research InstituteJupiter, FL, USA
| | - O J Marston
- Department of Pharmacology, University of CambridgeCambridge, United Kingdom
| | - J Rossi
- Department of Metabolism and Aging, The Scripps Research InstituteJupiter, FL, USA
| | - L K Burke
- Department of Pharmacology, University of CambridgeCambridge, United Kingdom
| | - P McDonald
- Department of Molecular Therapeutics and Translational Research Institute, The Scripps Research InstituteJupiter, FL, USA
| | - L K Heisler
- Department of Pharmacology, University of CambridgeCambridge, United Kingdom
| | - A A Butler
- Department of Metabolism and Aging, The Scripps Research InstituteJupiter, FL, USA
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Müller A, Möller M, Adams LA, Warren RM, Hoal EG, van Helden PD. Comparative analysis of a putative tuberculosis-susceptibility gene, MC3R, and pseudogene sequences in cattle, African buffalo, hyena, rhinoceros and other African bovids and ruminants. Cytogenet Genome Res 2012; 136:117-22. [PMID: 22286663 DOI: 10.1159/000335464] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2011] [Indexed: 12/17/2022] Open
Abstract
Studies in humans have suggested the possible involvement of melanocortin-3-receptor (MC3R) and other components of the central melanocortin system in host defense against mycobacteria. We report a genomic DNA nucleotide sequence highly homologous to human MC3R in several bovids and non-bovid African wildlife species. Nucleotide sequence analysis indicates that the orthologous genes of cattle and buffalo are highly homologous (89.4 and 90%, respectively) to the human MC3R gene. Sequence results also identified a typical non-functional, duplicated pseudogene, MC3RP, in 7 species from the family Bovidae. No pseudogene was found in animals outside Bovidae. The presence of the pseudogene in tuberculosis-susceptible species could have possible immunomodulatory effects on susceptibility to bovine tuberculosis infection, as well as a considerable influence on energy metabolism and food conversion efficiency.
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Affiliation(s)
- A Müller
- DST/NRF Centre of Excellence for Biomedical TB Research/MRC Centre for Molecular and Cellular Biology/ Division of Molecular Biology and Human Genetics, Faculty of Health Sciences, Stellenbosch University, Tygerberg, South Africa.
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Biebermann H, Kühnen P, Kleinau G, Krude H. The neuroendocrine circuitry controlled by POMC, MSH, and AGRP. Handb Exp Pharmacol 2012:47-75. [PMID: 22249810 DOI: 10.1007/978-3-642-24716-3_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Obesity is one of the most challenging health problems worldwide. Over the past few decades, our knowledge concerning mechanisms of weight regulation has increased tremendously leading to the identification of the leptin-melanocortin pathway. The filling level of energy stores is signaled to the brain, and the information is integrated by hypothalamic nuclei, resulting in a well-orchestrated response to food intake and energy expenditure to ensure constant body weight. One of the key players in this system is proopiomelanocortin (POMC), a precursor of a variety of neuropeptides. POMC-derived alpha- and beta-MSH play an important role in energy homeostasis by activating melanocortin receptors expressed in the arcuate nucleus (MC3R) and in the nucleus paraventricularis (MC4R). Activation of these two G protein-coupled receptors is antagonized by agouti-related peptide (AgRP). Naturally occurring mutations in this system were identified in patients suffering from common obesity as well as in patients demonstrating a phenotype of severe early-onset obesity, adrenal insufficiency, red hair, and pale skin. Detailed understanding of the complex system of POMC-AgRP-MC3R-MC4R and their interaction with other hypothalamic as well as peripheral signals is a prerequisite to combat the obesity epidemic.
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Affiliation(s)
- Heike Biebermann
- Institut für Experimentelle Pädiatrische Endokrinologie, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
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Obregón AM, Diaz E, Santos JL. Effect of the melanocortin-3 receptor Thr6Lys and Val81Ile genetic variants on body composition and substrate oxidation in Chilean obese children. J Physiol Biochem 2011; 68:71-6. [PMID: 21983807 DOI: 10.1007/s13105-011-0120-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 08/31/2011] [Indexed: 01/24/2023]
Abstract
Mice genetically deficient in the melanocortin-3 receptor gene are characterized by normal body weight, increased body fat, mild hypophagia, reduced locomotor activity, and increased respiratory quotient compared with wild-type mice. In humans, the 6Lys-81Ile haplotype of melanocortin-3 receptor (MC3R) gene has been associated with childhood obesity, higher body fat percentage, and reduced fat oxidation compared to non-carriers. The aim of this study was to evaluate the association between MC3R 6Lys-81Ile haplotype with body composition and substrate oxidation in response to moderate exercise in obese children. Eight Chilean obese children (aged 8-12) carriers of MC3R 6Lys-81Ile haplotype were compared with eight age-gender-matched obese non-carriers. Children were identified through a previous cross-sectional study on genetic determinants of childhood obesity (n = 229). Genotypes for MC3R Thr6Lys and Val81Ile were determined by polymerase chain reaction-restriction fragment length polymorphism. Body composition was assessed by the four-compartment model (dual-energy X-ray absorptiometry, total body water by the deuterium dilution technique, and total fat mass by air-displacement plethysmography). Substrate oxidation was assessed by indirect calorimetry in response to moderate exercise (60% VO(2 max)). Wilcoxon matched-pairs test was used to compare quantitative variables. No significant differences among carriers and non-carriers were found in anthropometrical and body composition measurements. The Carriers of the 6Lys-81Ile haplotype showed higher respiratory quotient (p = 0.06) and a significantly higher glucose oxidation (p = 0.01) compared with non-carriers after standardization for fat-free mass. Our results are consistent with a possible participation of MC3R 6Lys-81Ile variants in glucose oxidation in response to moderate exercise.
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Affiliation(s)
- Ana M Obregón
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O'Higgins 340, Santiago 8331150, Chile.
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Tounian P. Programming towards Childhood Obesity. ANNALS OF NUTRITION AND METABOLISM 2011; 58 Suppl 2:30-41. [DOI: 10.1159/000328038] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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