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Rajcsanyi LS, Zheng Y, Herpertz-Dahlmann B, Seitz J, de Zwaan M, Herzog W, Ehrlich S, Zipfel S, Giel K, Egberts K, Burghardt R, Föcker M, Antel J, Fischer-Posovszky P, Hebebrand J, Hinney A. Unexpected identification of obesity-associated mutations in LEP and MC4R genes in patients with anorexia nervosa. Sci Rep 2024; 14:7067. [PMID: 38528040 PMCID: PMC10963783 DOI: 10.1038/s41598-024-57517-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 03/19/2024] [Indexed: 03/27/2024] Open
Abstract
Mutations leading to a reduced or loss of function in genes of the leptin-melanocortin system confer a risk for monogenic forms of obesity. Yet, gain of function variants in the melanocortin-4-receptor (MC4R) gene predispose to a lower BMI. In individuals with reduced body weight, we thus expected mutations leading to an enhanced function in the respective genes, like leptin (LEP) and MC4R. Therefore, we have Sanger sequenced the coding regions of LEP and MC4R in 462 female patients with anorexia nervosa (AN), and 445 healthy-lean controls. In total, we have observed four and eight variants in LEP and MC4R, respectively. Previous studies showed different functional in vitro effects for the detected frameshift and non-synonymous variants: (1) LEP: reduced/loss of function (p.Val94Met), (2) MC4R: gain of function (p.Val103Ile, p.Ile251Leu), reduced or loss of function (p.Thr112Met, p.Ser127Leu, p.Leu211fsX) and without functional in vitro data (p.Val50Leut). In LEP, the variant p.Val94Met was detected in one patient with AN. For MC4R variants, one patient with AN carried the frameshift variant p.Leu211fsX. One patient with AN was heterozygous for two variants at the MC4R (p.Val103Ile and p.Ser127Leu). All other functionally relevant variants were detected in similar frequencies in patients with AN and lean individuals.
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Affiliation(s)
- Luisa Sophie Rajcsanyi
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstraße 174, 45147, Essen, Germany.
- Center for Translational Neuro- and Behavioural Sciences, University Hospital Essen, Essen, Germany.
- Section for Molecular Genetics of Mental Disorders, University Hospital Essen, Essen, Germany.
- Institute of Sex- and Gender-Sensitive Medicine, University Hospital Essen, Essen, Germany.
| | - Yiran Zheng
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstraße 174, 45147, Essen, Germany
- Center for Translational Neuro- and Behavioural Sciences, University Hospital Essen, Essen, Germany
| | - Beate Herpertz-Dahlmann
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Jochen Seitz
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstraße 174, 45147, Essen, Germany
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Martina de Zwaan
- Department of Psychosomatic Medicine and Psychotherapy, Hannover Medical School, Hannover, Germany
| | - Wolfgang Herzog
- Department of Internal Medicine II, General Internal and Psychosomatic Medicine, University of Heidelberg, Heidelberg, Germany
| | - Stefan Ehrlich
- Eating Disorders Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Dresden, Germany
- Translational Developmental Neuroscience Section, Division of Psychological and Social Medicine and Developmental Neurosciences, Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Stephan Zipfel
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tübingen, Tübingen, Germany
- Center of Excellence in Eating Disorders KOMET, Tübingen, Germany
| | - Katrin Giel
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tübingen, Tübingen, Germany
- Center of Excellence in Eating Disorders KOMET, Tübingen, Germany
| | - Karin Egberts
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Würzburg, Germany
| | - Roland Burghardt
- Oberberg Clinic for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Fasanenkiez, Berlin, Germany
| | - Manuel Föcker
- Department of Child and Adolescent Psychiatry, University Hospital Münster, Munster, Germany
- LWL-University Hospital Hamm for Child and Adolescent Psychiatry, Ruhr-University Bochum, Hamm, Germany
| | - Jochen Antel
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstraße 174, 45147, Essen, Germany
- Center for Translational Neuro- and Behavioural Sciences, University Hospital Essen, Essen, Germany
| | | | - Johannes Hebebrand
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstraße 174, 45147, Essen, Germany
- Center for Translational Neuro- and Behavioural Sciences, University Hospital Essen, Essen, Germany
| | - Anke Hinney
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Virchowstraße 174, 45147, Essen, Germany
- Center for Translational Neuro- and Behavioural Sciences, University Hospital Essen, Essen, Germany
- Section for Molecular Genetics of Mental Disorders, University Hospital Essen, Essen, Germany
- Institute of Sex- and Gender-Sensitive Medicine, University Hospital Essen, Essen, Germany
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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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Wei R, Li D, Jia S, Chen Y, Wang J. MC4R in Central and Peripheral Systems. Adv Biol (Weinh) 2023; 7:e2300035. [PMID: 37043700 DOI: 10.1002/adbi.202300035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/25/2023] [Indexed: 04/14/2023]
Abstract
Obesity has emerged as a critical and urgent health burden during the current global pandemic. Among multiple genetic causes, melanocortin receptor-4 (MC4R), involved in food intake and energy metabolism regulation through various signaling pathways, has been reported to be the lead genetic factor in severe and early onset obesity and hyperphagia disorders. Most previous studies have illustrated the roles of MC4R signaling in energy intake versus expenditure in the central system, while some evidence indicates that MC4R is also expressed in peripheral systems, such as the gut and endocrine organs. However, its physiopathological function remains poorly defined. This review aims to depict the central and peripheral roles of MC4R in energy metabolism and endocrine hormone homeostasis, the diversity of phenotypes, biased downstream signaling caused by distinct MC4R mutations, and current drug development targeting the receptor.
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Affiliation(s)
- Ran Wei
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Shanghai, 200025, China
- Department of Endocrinology, Shanghai Fifth People's Hospital, Fudan University, Shanghai, 200240, China
| | - Danjie Li
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Shanghai, 200025, China
| | - Sheng Jia
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Shanghai, 200025, China
| | - Yuhong Chen
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Shanghai, 200025, China
| | - Jiqiu Wang
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Shanghai, 200025, China
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Zheng Y, Rajcsanyi LS, Kowalczyk M, Giuranna J, Herpertz-Dahlmann B, Seitz J, de Zwaan M, Herzog W, Ehrlich S, Zipfel S, Giel K, Egberts K, Burghardt R, Föcker M, Al-Lahham S, Hebebrand J, Fuhrer D, Tan S, Zwanziger D, Peters T, Hinney A. Lipocalin 2 - mutation screen and serum levels in patients with anorexia nervosa or obesity and in lean individuals. Front Endocrinol (Lausanne) 2023; 14:1137308. [PMID: 37025415 PMCID: PMC10071025 DOI: 10.3389/fendo.2023.1137308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 03/09/2023] [Indexed: 04/08/2023] Open
Abstract
CONTEXT The bone-derived adipokine lipocalin-2 is relevant for body weight regulation by stimulating the leptin-melanocortin pathway. OBJECTIVE We aimed to (i) detect variants in the lipocalin-2 gene (LCN2) which are relevant for body weight regulation and/or anorexia nervosa (AN); (ii) describe and characterize the impact of LCN2 and MC4R variants on circulating lipocalin-2 level. METHODS Sanger sequencing of the coding region of LCN2 in 284 children and adolescents with severe obesity or 287 patients with anorexia nervosa. In-silico analyses to evaluate functional implications of detected LCN2 variants. TaqMan assays for rare non-synonymous variants (NSVs) in additional independent study groups. Serum levels of lipocalin-2 were measured by ELISA in 35 females with NSVs in either LCN2 or MC4R, and 33 matched controls without NSVs in the two genes. RESULTS Fourteen LCN2-variants (five NSVs) were detected. LCN2-p.Leu6Pro and p.Gly9Val located in the highly conserved signal peptide region may induce functional consequences. The secondary structure change of lipocalin-2 due to LCN2-p.Val89Ile may decrease solubility and results in a low lipocalin-2 level in a heterozygotes carrier (female recovered from AN). Lean individuals had lower lipocalin-2 levels compared to patients with obesity (p = 0.033). CONCLUSION Lipocalin-2 levels are positively associated with body mass index (BMI). Single LCN2-variants might have a profound effect on lipocalin-2 levels.
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Affiliation(s)
- Yiran Zheng
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- *Correspondence: Yiran Zheng,
| | - Luisa Sophie Rajcsanyi
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Manuela Kowalczyk
- Department of Endocrinology, Diabetes and Metabolism and Clinical Chemistry – Division of Laboratory Research, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Johanna Giuranna
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Beate Herpertz-Dahlmann
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Jochen Seitz
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Martina de Zwaan
- Department of Psychosomatic Medicine and Psychotherapy, Hannover Medical School, Hannover, Germany
| | - Wolfgang Herzog
- Department of Internal Medicine II, General Internal and Psychosomatic Medicine, University of Heidelberg, Heidelberg, Germany
| | - Stefan Ehrlich
- Translational Developmental Neuroscience Section, Department of Child and Adolescent Psychiatry, TU-Dresden, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
- Eating Disorders Research and Treatment Center, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Stephan Zipfel
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital, Tübingen, Germany
- Centre of Excellence for Eating Disorders, University of Tübingen, Tübingen, Germany
| | - Katrin Giel
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital, Tübingen, Germany
- Centre of Excellence for Eating Disorders, University of Tübingen, Tübingen, Germany
| | - Karin Egberts
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany
| | - Roland Burghardt
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Oberberg Fachklinik Fasanenkiez, Berlin, Germany
| | - Manuel Föcker
- Department of Child and Adolescent Psychiatry, University of Münster, Münster, Germany
| | - Saad Al-Lahham
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
| | - Johannes Hebebrand
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Dagmar Fuhrer
- Department of Endocrinology, Diabetes and Metabolism and Clinical Chemistry – Division of Laboratory Research, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Susanne Tan
- Department of Endocrinology, Diabetes and Metabolism, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Denise Zwanziger
- Department of Endocrinology, Diabetes and Metabolism and Clinical Chemistry – Division of Laboratory Research, 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, 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, Essen, Germany
- Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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Piper NBC, Whitfield EA, Stewart GD, Xu X, Furness SGB. Targeting appetite and satiety in diabetes and obesity, via G protein-coupled receptors. Biochem Pharmacol 2022; 202:115115. [PMID: 35671790 DOI: 10.1016/j.bcp.2022.115115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 11/17/2022]
Abstract
Type 2 diabetes and obesity have reached pandemic proportions throughout the world, so much so that the World Health Organisation coined the term "Globesity" to help encapsulate the magnitude of the problem. G protein-coupled receptors (GPCRs) are highly tractable drug targets due to their wide involvement in all aspects of physiology and pathophysiology, indeed, GPCRs are the targets of approximately 30% of the currently approved drugs. GPCRs are also broadly involved in key physiologies that underlie type 2 diabetes and obesity including feeding reward, appetite and satiety, regulation of blood glucose levels, energy homeostasis and adipose function. Despite this, only two GPCRs are the target of approved pharmaceuticals for treatment of type 2 diabetes and obesity. In this review we discuss the role of these, and select other candidate GPCRs, involved in various facets of type 2 diabetic or obese pathophysiology, how they might be targeted and the potential reasons why pharmaceuticals against these targets have not progressed to clinical use. Finally, we provide a perspective on the current development pipeline of anti-obesity drugs that target GPCRs.
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Affiliation(s)
- Noah B C Piper
- Receptor Transducer Coupling Laboratory, School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Emily A Whitfield
- Receptor Transducer Coupling Laboratory, School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Gregory D Stewart
- Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology Monash University, Parkville, VIC 3052, Australia
| | - Xiaomeng Xu
- Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology Monash University, Parkville, VIC 3052, Australia
| | - Sebastian G B Furness
- Receptor Transducer Coupling Laboratory, School of Biomedical Sciences, Faculty of Medicine, University of Queensland, St. Lucia, QLD 4072, Australia; Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences & Department of Pharmacology Monash University, Parkville, VIC 3052, Australia.
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Tao YX. Mutations in melanocortin-4 receptor: From fish to men. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 189:215-257. [PMID: 35595350 DOI: 10.1016/bs.pmbts.2022.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Melanocortin-4 receptor (MC4R), expressed abundantly in the hypothalamus, is a critical regulator of energy homeostasis, including both food intake and energy expenditure. Shortly after the publication in 1997 of the Mc4r knockout phenotypes in mice, including increased food intake and severe obesity, the first mutations in MC4R were reported in humans in 1998. Studies in the subsequent two decades have established MC4R mutation as the most common monogenic form of obesity, especially in early-onset severe obesity. Studies in animals, from fish to mammals, have established the conserved physiological roles of MC4R in all vertebrates in regulating energy balance. Drug targeting MC4R has been recently approved for treating morbid genetic obesity. How the MC4R can be exploited for animal production is highly worthy of active investigation.
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States.
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Cui M, Zhou Q, Xu Y, Weng Y, Yao D, Zhao S, Song G. Crystal structure of a constitutive active mutant of adenosine A 2A receptor. IUCRJ 2022; 9:333-341. [PMID: 35546802 PMCID: PMC9067115 DOI: 10.1107/s2052252522001907] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/17/2022] [Indexed: 06/03/2023]
Abstract
The adenosine A2A receptor (A2AAR) is a prototypical member of the class A subfamily of G-protein-coupled receptors (GPCRs) that is widely distributed in various tissues and organs of the human body, and participates in many important signal-regulation processes. We have previously summarized a common activation pathway of class A GPCRs in which a series of conserved residues/motifs undergo conformational change during extracellular agonist binding and finally induce the coupling of intracellular G protein. Through this mechanism we have successfully predicted several novel constitutive active or inactive mutations for A2AAR. To reveal the molecular mechanism of mutation-induced constitutive activity, we determined the structure of a typical mutant I92N complexed with the agonist UK-432097. The mutated I92N forms a hydrophilic interaction network with nearby residues including Trp6.48 of the CWxP motif, which is absent in wild-type A2AAR. Although the mutant structure is similar overall to the previously determined intermediate-state A2AAR structure (PDB ID 3qak) [Xu, Wu, Katritch, Han, Jacobson, Gao, Cherezov & Stevens (2011). Science, 332, 322-327 ▸], molecular dynamics simulations suggest that the I92N mutant stabilizes the metastable intermediate state through the hydrophilic interaction network and favors the conformational transition of the receptor towards the active state. This research provides a structural template towards the special pharmacological outcome triggered by conformational mutation and sheds light on future structural or pharmaco-logical studies among class A GPCRs.
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Affiliation(s)
- Min Cui
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, People’s Republic of China
| | - Qingtong Zhou
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, People’s Republic of China
| | - Yueming Xu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, People’s Republic of China
| | - Yuan Weng
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, People’s Republic of China
| | - Deqiang Yao
- State Key Laboratory of Oncogenes and Related Genes, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, People’s Republic of China
| | - Suwen Zhao
- iHuman Institute, ShanghaiTech University, Shanghai 201210, People’s Republic of China
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, People’s Republic of China
| | - Gaojie Song
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, People’s Republic of China
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Szalanczy AM, Key CCC, Woods LCS. Genetic variation in satiety signaling and hypothalamic inflammation: merging fields for the study of obesity. J Nutr Biochem 2022; 101:108928. [PMID: 34936921 PMCID: PMC8959400 DOI: 10.1016/j.jnutbio.2021.108928] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 11/08/2021] [Accepted: 12/01/2021] [Indexed: 02/07/2023]
Abstract
Although obesity has been a longstanding health crisis, the genetic architecture of the disease remains poorly understood. Genome-wide association studies have identified many genomic loci associated with obesity, with genes being enriched in the brain, particularly in the hypothalamus. This points to the role of the central nervous system (CNS) in predisposition to obesity, and we emphasize here several key genes along the satiety signaling pathway involved in genetic susceptibility. Interest has also risen regarding the chronic, low-grade obesity-associated inflammation, with a growing concern toward inflammation in the hypothalamus as a precursor to obesity. Recent studies have found that genetic variation in inflammatory genes play a role in obesity susceptibility, and we highlight here several key genes. Despite the interest in the genetic variants of these pathways individually, there is a lack of research that investigates the relationship between the two. Understanding the interplay between genetic variation in obesity genes enriched in the CNS and inflammation genes will advance our understanding of obesity etiology and heterogeneity, improve genetic risk prediction analyses, and highlight new drug targets for the treatment of obesity. Additionally, this increased knowledge will assist in physician's ability to develop personalized nutrition and medication strategies for combating the obesity epidemic. Though it often seems to present universally, obesity is a highly individual disease, and there remains a need in the field to develop methods to treat at the individual level.
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Structures of active melanocortin-4 receptor-Gs-protein complexes with NDP-α-MSH and setmelanotide. Cell Res 2021; 31:1176-1189. [PMID: 34561620 PMCID: PMC8563958 DOI: 10.1038/s41422-021-00569-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 08/31/2021] [Indexed: 02/07/2023] Open
Abstract
The melanocortin-4 receptor (MC4R), a hypothalamic master regulator of energy homeostasis and appetite, is a class A G-protein-coupled receptor and a prime target for the pharmacological treatment of obesity. Here, we present cryo-electron microscopy structures of MC4R–Gs-protein complexes with two drugs recently approved by the FDA, the peptide agonists NDP-α-MSH and setmelanotide, with 2.9 Å and 2.6 Å resolution. Together with signaling data from structure-derived MC4R mutants, the complex structures reveal the agonist-induced origin of transmembrane helix (TM) 6-regulated receptor activation. The ligand-binding modes of NDP-α-MSH, a high-affinity linear variant of the endogenous agonist α-MSH, and setmelanotide, a cyclic anti-obesity drug with biased signaling toward Gq/11, underline the key role of TM3 in ligand-specific interactions and of calcium ion as a ligand-adaptable cofactor. The agonist-specific TM3 interplay subsequently impacts receptor–Gs-protein interfaces at intracellular loop 2, which also regulates the G-protein coupling profile of this promiscuous receptor. Finally, our structures reveal mechanistic details of MC4R activation/inhibition, and provide important insights into the regulation of the receptor signaling profile which will facilitate the development of tailored anti-obesity drugs.
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10
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Israeli H, Degtjarik O, Fierro F, Chunilal V, Gill AK, Roth NJ, Botta J, Prabahar V, Peleg Y, Chan LF, Ben-Zvi D, McCormick PJ, Niv MY, Shalev-Benami M. Structure reveals the activation mechanism of the MC4 receptor to initiate satiation signaling. Science 2021; 372:808-814. [PMID: 33858992 DOI: 10.1126/science.abf7958] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/08/2021] [Indexed: 12/18/2022]
Abstract
Obesity is a global epidemic that causes morbidity and impaired quality of life. The melanocortin receptor 4 (MC4R) is at the crux of appetite, energy homeostasis, and body-weight control in the central nervous system and is a prime target for anti-obesity drugs. Here, we present the cryo-electron microscopy (cryo-EM) structure of the human MC4R-Gs signaling complex bound to the agonist setmelanotide, a cyclic peptide recently approved for the treatment of obesity. The work reveals the mechanism of MC4R activation, highlighting a molecular switch that initiates satiation signaling. In addition, our findings indicate that calcium (Ca2+) is required for agonist, but not antagonist, efficacy. These results fill a gap in the understanding of MC4R activation and could guide the design of future weight-management drugs.
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Affiliation(s)
- Hadar Israeli
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Oksana Degtjarik
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Fabrizio Fierro
- The Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot, Israel
- The Fritz Haber Center for Molecular Dynamics, The Hebrew University, Jerusalem, Israel
| | - Vidicha Chunilal
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary, University of London, Charterhouse Square, London, UK
| | - Amandeep Kaur Gill
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary, University of London, Charterhouse Square, London, UK
| | - Nicolas J Roth
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary, University of London, Charterhouse Square, London, UK
| | - Joaquin Botta
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary, University of London, Charterhouse Square, London, UK
| | - Vadivel Prabahar
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yoav Peleg
- Structural Proteomics Unit (SPU), Life Sciences Core Facilities (LSCF), Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Li F Chan
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary, University of London, Charterhouse Square, London, UK
| | - Danny Ben-Zvi
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
| | - Peter J McCormick
- Centre for Endocrinology, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary, University of London, Charterhouse Square, London, UK.
| | - Masha Y Niv
- The Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot, Israel.
- The Fritz Haber Center for Molecular Dynamics, The Hebrew University, Jerusalem, Israel
| | - Moran Shalev-Benami
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
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11
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Ericson MD, Haslach EM, Schnell SM, Freeman KT, Xiang ZM, Portillo FP, Speth R, Litherland SA, Haskell-Luevano C. Discovery of Molecular Interactions of the Human Melanocortin-4 Receptor (hMC4R) Asp189 (D189) Amino Acid with the Endogenous G-Protein-Coupled Receptor (GPCR) Antagonist Agouti-Related Protein (AGRP) Provides Insights to AGRP's Inverse Agonist Pharmacology at the hMC4R. ACS Chem Neurosci 2021; 12:542-556. [PMID: 33470098 DOI: 10.1021/acschemneuro.0c00755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The melanocortin receptors (MCRs) are important for numerous biological pathways, including feeding behavior and energy homeostasis. In addition to endogenous peptide agonists, this receptor family has two naturally occurring endogenous antagonists, agouti and agouti-related protein (AGRP). At the melanocortin-4 receptor (MC4R), the AGRP ligand functions as an endogenous inverse agonist in the absence of agonist and as a competitive antagonist in the presence of agonist. At the melanocortin-3 receptor (MC3R), AGRP functions solely as a competitive antagonist in the presence of agonist. The molecular interactions that differentiate AGRP's inverse agonist activity at the MC4R have remained elusive until the findings reported herein. Upon the basis of homology molecular modeling approaches, we previously postulated a unique interaction between the D189 position of the hMC4R and Asn114 of AGRP. To further test this hypothesis, six D189 mutant hMC4Rs (D189A, D189E, D189N, D189Q, D189S, and D189K) were generated and pharmacologically characterized resulting in the discovery of differences in inverse agonist activity of AGRP and an 11 macrocyclic compound library. These data support the hypothesized interaction between the hMC4R D189 position and Asn114 residue of AGRP and define critical ligand-receptor molecular interactions responsible for the inverse agonist activity of AGRP at the hMC4R.
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Affiliation(s)
- Mark D. Ericson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, United States
| | - Erica M. Haslach
- Departments of Pharmacodynamics and Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
| | - Sathya M. Schnell
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, United States
| | - Katie T. Freeman
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, United States
| | - Zhimin M. Xiang
- Departments of Pharmacodynamics and Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
| | - Frederico P. Portillo
- Departments of Pharmacodynamics and Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
| | - Robert Speth
- College of Pharmacy, Nova Southeastern University, Fort Lauderdale, Florida 33328, United States
- College of Medicine, Georgetown University, Washington, D.C. 20057, United States
| | - Sally A. Litherland
- Translational Research, Florida Hospital Cancer Institute, Orlando, Florida 32804, United States
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, United States
- Departments of Pharmacodynamics and Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
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12
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Salum KCR, de Souza GO, Abreu GDM, Campos Junior M, Kohlrausch FB, Carneiro JRI, Nogueira Neto JF, Magno FCCM, Rosado EL, Palhinha L, Maya-Monteiro CM, de Cabello GMK, Cabello PH, Bozza PT, Zembrzuski VM, da Fonseca ACP. Identification of a Rare and Potential Pathogenic MC4R Variant in a Brazilian Patient With Adulthood-Onset Severe Obesity. Front Genet 2020; 11:608840. [PMID: 33362866 PMCID: PMC7756028 DOI: 10.3389/fgene.2020.608840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 11/19/2020] [Indexed: 11/16/2022] Open
Abstract
Background The melanocortinergic pathway orchestrates the energy homeostasis and impairments in this system often lead to an increase in body weight. Rare variants in the melanocortin 4 receptor (MC4R) gene resulting in partial or complete loss of function have been described with autosomal co-dominant inheritance. These mutations are the most common cause of non-syndromic monogenic obesity. In this context, this study aimed to sequence the MC4R gene in a Brazilian cohort of adults with severe obesity. Methods This study included 163 unrelated probands with Body Mass Index (BMI) ≥ 35 kg/m2, stratified into three groups, according to the period of obesity onset. From the total sample, 25 patients were enrolled in the childhood-onset group (0–11 years), 19 patients in the adolescence/youth-onset group (12–21 years), and 119 patients in the adult-onset group (>21 years). Blood pressure, anthropometric and biochemical characteristics were obtained, and the MC4R coding region of each subject’s DNA was assessed using automated Sanger sequencing. Results Significant anthropometric differences between the groups were observed. Higher body weight and BMI medians were found in patients with childhood-onset or adolescence/youth-onset when compared to the adulthood-onset obesity group. A total of five mutations were identified, including four missense variants: p.Ser36Thr, p.Val103Ile, p.Ala175Thr, and p.Ile251Leu. Additionally, we observed one synonymous variant (p.Ile198=). The p.Ala175Thr variant was identified in a female case with severe obesity and adulthood-onset. This variant was previously described as a partial loss-of-function mutation, in which the minor allele poses dominant-negative effect, probably resulting in reduced cAMP activity. Conclusion This study showed a prevalence of common and rare variants in a cohort of Brazilian adults with severe obesity and candidates to bariatric surgery. We have identified a rare potentially pathogenic MC4R variant in a Brazilian patient with severe and adulthood-onset obesity.
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Affiliation(s)
- Kaio Cezar Rodrigues Salum
- Human Genetic Laboratory, Department of General Biology, Institute of Biology, Federal Fluminense University, Niterói, Brazil.,Human Genetics Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | | | | | - Mário Campos Junior
- Human Genetics Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Fabiana Barzotto Kohlrausch
- Human Genetic Laboratory, Department of General Biology, Institute of Biology, Federal Fluminense University, Niterói, Brazil
| | - João Regis Ivar Carneiro
- Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Eliane Lopes Rosado
- Institute of Nutrition Josué de Castro, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lohanna Palhinha
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | | | | | - Pedro Hernán Cabello
- Human Genetics Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,Human Genetics Laboratory, Grande Rio University, Rio de Janeiro, Brazil
| | - Patrícia Torres Bozza
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | | | - Ana Carolina Proença da Fonseca
- Human Genetics Laboratory, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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13
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Rojo D, McCarthy C, Raingo J, Rubinstein M. Mouse models for V103I and I251L gain of function variants of the human MC4R display decreased adiposity but are not protected against a hypercaloric diet. Mol Metab 2020; 42:101077. [PMID: 32916307 PMCID: PMC7559519 DOI: 10.1016/j.molmet.2020.101077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/20/2020] [Accepted: 09/06/2020] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE The melanocortin 4 receptor (MC4R) is a G protein-coupled receptor that plays major roles in the central control of energy balance. Loss-of-function mutations of MC4R constitute the most common monogenic cause of early-onset extreme obesity in humans, whereas gain-of-function mutations appear to be protective. In particular, two relatively frequent alleles carrying the non-synonymous coding mutations V103I or I251L are associated with lower risks of obesity and type-2 diabetes. Although V103I and I251L MC4Rs showed more efficient signalling in transfected cells, their specific effects in live animals remain unexplored. Here, we investigated whether the introduction of V103I and I251L mutations into the mouse MC4R leads to a lean phenotype and provides protection against an obesogenic diet. METHODS Using CRISPR/Cas9, we generated two novel strains of mice carrying single-nucleotide mutations into the mouse Mc4r which are identical to those present in V103I and I251L MCR4 human alleles, and studied their phenotypic outcomes in mice fed with normal chow or a high-fat diet. In particular, we measured body weight progression, food intake and adiposity. In addition, we analysed glucose homeostasis through glucose and insulin tolerance tests. RESULTS We found that homozygous V103I females displayed shorter longitudinal length and decreased abdominal white fat, whereas homozygous I251L females were also shorter and leaner due to decreased weight in all white fat pads examined. Homozygous Mc4rV103I/V103I and Mc4rI251L/I251L mice of both sexes showed improved glucose homeostasis when challenged in a glucose tolerance test, whereas Mc4rI251L/I251L females showed improved responses to insulin. Despite being leaner and metabolically more efficient, V103I and I251L mutants fed with a hypercaloric diet increased their fasting glucose levels and adiposity similar to their wild-type littermates. CONCLUSIONS Our results demonstrate that mice carrying V103I and I251L MC4R mutations displayed gain-of-function phenotypes that were more evident in females. However, hypermorphic MC4R mutants were as susceptible as their control littermates to the obesogenic and diabetogenic effects elicited by a long-term hypercaloric diet, highlighting the importance of healthy feeding habits even under favourable genetic conditions.
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Affiliation(s)
- Daniela Rojo
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, 1428 Buenos Aires, Argentina
| | - Clara McCarthy
- Instituto Multidisciplinario de Biología Celular, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de La Plata and Comisión de Investigaciones de la Provincia de Buenos Aires, La Plata, Province of Buenos Aires, Argentina
| | - Jesica Raingo
- Instituto Multidisciplinario de Biología Celular, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de La Plata and Comisión de Investigaciones de la Provincia de Buenos Aires, La Plata, Province of Buenos Aires, Argentina
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, 1428 Buenos Aires, Argentina; Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA.
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14
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Yang LK, Tao YX. Alanine Scanning Mutagenesis of the DRYxxI Motif and Intracellular Loop 2 of Human Melanocortin-4 Receptor. Int J Mol Sci 2020; 21:ijms21207611. [PMID: 33076233 PMCID: PMC7589821 DOI: 10.3390/ijms21207611] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/10/2020] [Accepted: 10/11/2020] [Indexed: 12/15/2022] Open
Abstract
The melanocortin-4 receptor (MC4R) is a member of the G-protein-coupled receptor (GPCR) superfamily, which has been extensively studied in obesity pathogenesis due to its critical role in regulating energy homeostasis. Both the Gs-cAMP and ERK1/2 cascades are known as important intracellular signaling pathways initiated by the MC4R. The DRYxxI motif at the end of transmembrane domain 3 and the intracellular loop 2 (ICL2) are thought to be crucial for receptor function in several GPCRs. To study the functions of this domain in MC4R, we performed alanine-scanning mutagenesis on seventeen residues. We showed that one residue was critical for receptor cell surface expression. Eight residues were important for ligand binding. Mutations of three residues impaired Gs-cAMP signaling without changing the binding properties. Investigation on constitutive activities of all the mutants in the cAMP pathway revealed that six residues were involved in constraining the receptor in inactive states and five residues were important for receptor activation in the absence of an agonist. In addition, mutations of four residues impaired the ligand-stimulated ERK1/2 signaling pathway without affecting the binding properties. We also showed that some mutants were biased to the Gs-cAMP or ERK1/2 signaling pathway. In summary, we demonstrated that the DRYxxI motif and ICL2 were important for MC4R function.
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15
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Obesity treatment effect in Danish children and adolescents carrying Melanocortin-4 Receptor mutations. Int J Obes (Lond) 2020; 45:66-76. [PMID: 32921795 PMCID: PMC7752754 DOI: 10.1038/s41366-020-00673-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 08/10/2020] [Accepted: 09/03/2020] [Indexed: 11/20/2022]
Abstract
Objectives To determine the prevalence of Melanocortin-4 Receptor (MC4R) mutations in a cohort of children and adolescents with overweight or obesity and to determine whether treatment responses differed between carriers and noncarriers. Methods Using target region capture sequencing, an MC4R mutation screen was performed in 1261 Danish children and adolescents enrolled at a tertiary multidisciplinary childhood obesity treatment center. Measurements of anthropometrics, blood pressure, fasting blood biochemistry including lipid and hormone levels, and dual-energy X-ray absorptiometry were performed at baseline and throughout treatment. Results Of 1209 children and adolescents that met all criteria to be included in the described analyses, 30 (2.5%) carried damaging or unresolved MC4R mutations. At baseline, mutation carriers exhibited higher concentrations of plasma thyroid-stimulating hormone (p = 0.003), and lower concentrations of plasma thyroxine (p = 0.010) compared to noncarriers. After a median of 1 year of treatment (range 0.5–4.0 years), body mass index (BMI) standard deviation score (SDS) was reduced in noncarriers but not in carriers, and this difference in treatment response was statistically significant (p = 0.005). Furthermore, HDL cholesterol was reduced in carriers, a response significantly different from that of noncarriers (p = 0.017). Conclusion Among Danish children and adolescents with overweight or obesity entering a tertiary lifestyle intervention, 2.5% carried damaging or unresolved MC4R mutations. In contrast to noncarriers, carriers of damaging or unresolved MC4R mutations failed to reduce their BMI SDS during obesity treatment, indicating a need for personalized treatment based on the MC4R genotype.
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16
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Chami N, Preuss M, Walker RW, Moscati A, Loos RJF. The role of polygenic susceptibility to obesity among carriers of pathogenic mutations in MC4R in the UK Biobank population. PLoS Med 2020; 17:e1003196. [PMID: 32692746 PMCID: PMC7373259 DOI: 10.1371/journal.pmed.1003196] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 06/16/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Melanocortin 4 receptor (MC4R) deficiency, caused by mutations in MC4R, is the most common cause of monogenic forms of obesity. However, these mutations have often been identified in small-scale, case-focused studies. Here, we assess the penetrance of previously reported MC4R mutations at a population level. Furthermore, we examine why some carriers of pathogenic mutations remain of normal weight, to gain insight into the mechanisms that control body weight. METHODS AND FINDINGS We identified 59 known obesity-increasing mutations in MC4R from the Human Gene Mutation Database (HGMD) and Clinvar. We assessed their penetrance and effect on obesity (body mass index [BMI] ≥ 30 kg/m2) in >450,000 individuals (age 40-69 years) of the UK Biobank, a population-based cohort study. Of these 59 mutations, only 11 had moderate-to-high penetrance and increased the odds of obesity by more than 2-fold. We subsequently focused on these 11 mutations and examined differences between carriers of normal weight and carriers with obesity. Twenty-eight of the 182 carriers of these 11 mutations were of normal weight. Body composition of carriers of normal weight was similar to noncarriers of normal weight, whereas among individuals with obesity, carriers had a somewhat higher BMI than noncarriers (1.44 ± 0.07 standard deviation scores [SDSs] ± standard error [SE] versus 1.29 ± 0.001, P = 0.03), because of greater lean mass (1.44 ± 0.09 versus 1.15 ± 0.002, P = 0.002). Carriers of normal weight more often reported that, already at age 10 years, their body size was below average or average (72%) compared with carriers with obesity (48%) (P = 0.01). To assess the polygenic contribution to body weight in carriers of normal weight and carriers with obesity, we calculated a genome-wide polygenic risk score for BMI (PRSBMI). The PRSBMI of carriers of normal weight (PRSBMI = -0.64 ± 0.18) was significantly lower than of carriers with obesity (0.40 ± 0.11; P = 1.7 × 10-6), and tended to be lower than that of noncarriers of normal weight (-0.29 ± 0.003; P = 0.05). Among carriers, those with a low PRSBMI (bottom quartile) have an approximately 5-kg/m2 lower BMI (approximately 14 kg of body weight for a 1.7-m-tall person) than those with a high PRS (top quartile). Because the UK Biobank population is healthier than the general population in the United Kingdom, penetrance may have been somewhat underestimated. CONCLUSIONS We showed that large-scale data are needed to validate the impact of mutations observed in small-scale and case-focused studies. Furthermore, we observed that despite the key role of MC4R in obesity, the effects of pathogenic MC4R mutations may be countered, at least in part, by a low polygenic risk potentially representing other innate mechanisms implicated in body weight regulation.
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Affiliation(s)
- Nathalie Chami
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Michael Preuss
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Ryan W. Walker
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Arden Moscati
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Ruth J. F. Loos
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
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17
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Vázquez-Moreno M, Zeng H, Locia-Morales D, Peralta-Romero J, Asif H, Maharaj A, Tam V, Romero-Figueroa MDS, Sosa-Bustamante GP, Méndez-Martínez S, Mejía-Benítez A, Valladares-Salgado A, Wacher-Rodarte N, Cruz M, Meyre D. The Melanocortin 4 Receptor p.Ile269Asn Mutation Is Associated with Childhood and Adult Obesity in Mexicans. J Clin Endocrinol Metab 2020; 105:5679482. [PMID: 31841602 DOI: 10.1210/clinem/dgz276] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 12/13/2019] [Indexed: 12/19/2022]
Abstract
CONTEXT Rare partial/complete loss-of-function mutations in the melanocortin-4 receptor (MC4R) gene are the most common cause of Mendelian obesity in European populations, but their contribution to obesity in the Mexican population is unclear. OBJECTIVE AND DESIGN We investigated whether deleterious mutations in MC4R contribute to obesity in Mexican children and adults. RESULTS We provide evidence that the MC4R p.Ile269Asn (rs79783591) mutation may have arisen in modern human populations from a founder event in native Mexicans. The MC4R Isoleucine 269 is perfectly conserved across 184 species, which suggests a critical role for the amino acid in MC4R activity. Four in silico tools (SIFT, PolyPhen-2, CADD, MutPred2) predicted a deleterious impact of the p.Ile269Asn substitution on MC4R function. The MC4R p.Ile269Asn mutation was associated with childhood (Ncontrols = 952, Ncases = 661, odds ratio (OR) = 3.06, 95% confidence interval (95%CI) [1.94-4.85]) and adult obesity (Ncontrols = 1445, Ncases = 2,487, OR = 2.58, 95%CI [1.52-4.39]). The frequency of the MC4R p.Ile269Asn mutation ranged from 0.52 to 0.59% and 1.53 to 1.59% in children and adults with normal weight and obesity, respectively. The MC4R p.Ile269Asn mutation co-segregated perfectly with obesity in 5 multigenerational Mexican pedigrees. While adults with obesity carrying the p.Ile269Asn mutation had higher BMI values than noncarriers, this trend was not observed in children. The MC4R p.Ile269Asn mutation accounted for a population attributable risk of 1.28% and 0.68% for childhood and adult obesity, respectively, in the Mexican population. CONCLUSION The MC4R p.Ile269Asn mutation may have emerged as a founder mutation in native Mexicans and is associated with childhood and adult obesity in the modern Mexican population.
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Affiliation(s)
- Miguel Vázquez-Moreno
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social, Ciudad de México, México
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Helen Zeng
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Daniel Locia-Morales
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Jesús Peralta-Romero
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Hamza Asif
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Arjuna Maharaj
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Vivian Tam
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - María D S Romero-Figueroa
- Centro de Investigación en Ciencias de la Salud (CICSA), Facultad de Ciencias de la Salud, Universidad Anáhuac, Campus Norte, Huixquilucan, México
| | | | - Socorro Méndez-Martínez
- Coordinación de Investigación en Salud, Instituto Mexicano del Seguro Social Puebla, Puebla, México
| | - Aurora Mejía-Benítez
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Adan Valladares-Salgado
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Niels Wacher-Rodarte
- Unidad de Investigación en Epidemiología Clínica, Hospital de Especialidades Bernardo Sepúlveda, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | | | - Miguel Cruz
- Unidad de Investigación Médica en Bioquímica, Hospital de Especialidades, Centro Médico Nacional Siglo XXI del Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - David Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Canada
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18
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Differential Signaling Profiles of MC4R Mutations with Three Different Ligands. Int J Mol Sci 2020; 21:ijms21041224. [PMID: 32059383 PMCID: PMC7072973 DOI: 10.3390/ijms21041224] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/06/2020] [Accepted: 02/06/2020] [Indexed: 12/21/2022] Open
Abstract
The melanocortin 4 receptor (MC4R) is a key player in hypothalamic weight regulation and energy expenditure as part of the leptin–melanocortin pathway. Mutations in this G protein coupled receptor (GPCR) are the most common cause for monogenetic obesity, which appears to be mediated by changes in the anorectic action of MC4R via GS-dependent cyclic adenosine-monophosphate (cAMP) signaling as well as other signaling pathways. To study potential bias in the effects of MC4R mutations between the different signaling pathways, we investigated three major MC4R mutations: a GS loss-of-function (S127L) and a GS gain-of-function mutant (H158R), as well as the most common European single nucleotide polymorphism (V103I). We tested signaling of all four major G protein families plus extracellular regulated kinase (ERK) phosphorylation and β-arrestin2 recruitment, using the two endogenous agonists, α- and β-melanocyte stimulating hormone (MSH), along with a synthetic peptide agonist (NDP-α-MSH). The S127L mutation led to a full loss-of-function in all investigated pathways, whereas V103I and H158R were clearly biased towards the Gq/11 pathway when challenged with the endogenous ligands. These results show that MC4R mutations can cause vastly different changes in the various MC4R signaling pathways and highlight the importance of a comprehensive characterization of receptor mutations.
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Bakhashab S, Filimban N, Altall RM, Nassir R, Qusti SY, Alqahtani MH, Abuzenadah AM, Dallol A. The Effect Sizes of PPARγ rs1801282 , FTO rs9939609, and MC4R rs2229616 Variants on Type 2 Diabetes Mellitus Risk among the Western Saudi Population: A Cross-Sectional Prospective Study. Genes (Basel) 2020; 11:genes11010098. [PMID: 31947684 PMCID: PMC7017045 DOI: 10.3390/genes11010098] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/05/2020] [Accepted: 01/09/2020] [Indexed: 12/20/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a common polygenic disease with associated comorbidities. Obesity is a major risk factor for the development of T2DM. The aim of this study is to determine the allele and genotype frequency of peroxisome proliferator-activated receptor-γ (PPARγ) rs1801282, fat mass and obesity-associated protein (FTO) rs9939609, and melanocortin 4 receptor (MC4R) rs2229616 polymorphisms and their association with risk of T2DM in the western Saudi population as mediators of adiposity phenotypes. In a cross-sectional prospective study, genomic DNA from control and T2DM patients were isolated and genotyped for these single-nucleotide polymorphisms. There was a significant association of the MC4R rs2229616 variant with T2DM, but no association with T2DM was detected with PPARγ rs1801282 or FTO rs9939609. The combination of C/C for PPARγ rs1801282, A/A for FTO rs9939609, and C/C for MC4R rs2229616 increased the risk of T2DM by 1.82. The A/T genotype for FTO rs9939609 was predicted to decrease the risk of T2DM when combined with C/C for PPARγ rs1801282 and C/C for MC4R rs2229616 or C/C for PPARγ rs1801282 and C/T MC4R rs2229616. In conclusion, our study showed the risk of the assessed variants for the development of T2DM in the Saudi population.
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Affiliation(s)
- Sherin Bakhashab
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, P.O Box 80218, Jeddah 21589, Saudi Arabia; (N.F.); (R.M.A.); (S.Y.Q.)
- Center of Innovation in Personalized Medicine, King Abdulaziz University, P.O Box 80216, Jeddah 21589, Saudi Arabia; (A.M.A.); (A.D.)
- Correspondence: ; Tel.: +966126400000
| | - Najlaa Filimban
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, P.O Box 80218, Jeddah 21589, Saudi Arabia; (N.F.); (R.M.A.); (S.Y.Q.)
- King Faisal Specialist Hospital and Research Center, Clinical Genomics, Department of Genetics, P.O. Box 3354, Riyadh 11211, Saudi Arabia
| | - Rana M. Altall
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, P.O Box 80218, Jeddah 21589, Saudi Arabia; (N.F.); (R.M.A.); (S.Y.Q.)
| | - Rami Nassir
- Department of Pathology, Faculty of Medicine, Umm Al-Qura University, P.O. Box 715, Makkah 21955, Saudi Arabia;
| | - Safaa Y. Qusti
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, P.O Box 80218, Jeddah 21589, Saudi Arabia; (N.F.); (R.M.A.); (S.Y.Q.)
| | - Mohammed H. Alqahtani
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O Box 80216, Jeddah 21589, Saudi Arabia;
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, P.O Box 80216, Jeddah 21589, Saudi Arabia
| | - Adel M. Abuzenadah
- Center of Innovation in Personalized Medicine, King Abdulaziz University, P.O Box 80216, Jeddah 21589, Saudi Arabia; (A.M.A.); (A.D.)
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O Box 80216, Jeddah 21589, Saudi Arabia;
| | - Ashraf Dallol
- Center of Innovation in Personalized Medicine, King Abdulaziz University, P.O Box 80216, Jeddah 21589, Saudi Arabia; (A.M.A.); (A.D.)
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O Box 80216, Jeddah 21589, Saudi Arabia;
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20
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Khera AV, Chaffin M, Wade KH, Zahid S, Brancale J, Xia R, Distefano M, Senol-Cosar O, Haas ME, Bick A, Aragam KG, Lander ES, Smith GD, Mason-Suares H, Fornage M, Lebo M, Timpson NJ, Kaplan LM, Kathiresan S. Polygenic Prediction of Weight and Obesity Trajectories from Birth to Adulthood. Cell 2019; 177:587-596.e9. [PMID: 31002795 PMCID: PMC6661115 DOI: 10.1016/j.cell.2019.03.028] [Citation(s) in RCA: 389] [Impact Index Per Article: 77.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 11/07/2018] [Accepted: 03/12/2019] [Indexed: 12/30/2022]
Abstract
Severe obesity is a rapidly growing global health threat. Although often attributed to unhealthy lifestyle choices or environmental factors, obesity is known to be heritable and highly polygenic; the majority of inherited susceptibility is related to the cumulative effect of many common DNA variants. Here we derive and validate a new polygenic predictor comprised of 2.1 million common variants to quantify this susceptibility and test this predictor in more than 300,000 individuals ranging from middle age to birth. Among middle-aged adults, we observe a 13-kg gradient in weight and a 25-fold gradient in risk of severe obesity across polygenic score deciles. In a longitudinal birth cohort, we note minimal differences in birthweight across score deciles, but a significant gradient emerged in early childhood and reached 12 kg by 18 years of age. This new approach to quantify inherited susceptibility to obesity affords new opportunities for clinical prevention and mechanistic assessment.
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Affiliation(s)
- Amit V Khera
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Division of Cardiology, Massachusetts General Hospital, Boston, MA 02114, USA; Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
| | - Mark Chaffin
- Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Kaitlin H Wade
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 1TH, UK; Population Health Science, Bristol Medical School, Bristol, Bristol BS8 1TH, UK; Avon Longitudinal Study of Parents and Children, Bristol BS8 1TH, UK
| | - Sohail Zahid
- Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Joseph Brancale
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA; Obesity, Metabolism, and Nutrition Institute, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Rui Xia
- The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Marina Distefano
- Laboratory for Molecular Medicine, Partners HealthCare Personalized Medicine, Cambridge, MA 02139, USA; Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Pathology, Harvard Medical School, Cambridge, MA 02115, USA
| | - Ozlem Senol-Cosar
- Laboratory for Molecular Medicine, Partners HealthCare Personalized Medicine, Cambridge, MA 02139, USA; Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Pathology, Harvard Medical School, Cambridge, MA 02115, USA
| | - Mary E Haas
- Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Alexander Bick
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Krishna G Aragam
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Division of Cardiology, Massachusetts General Hospital, Boston, MA 02114, USA; Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Eric S Lander
- Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Program in Health Sciences and Technology, Harvard Medical School, Boston, MA 02115, USA
| | - George Davey Smith
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 1TH, UK; Population Health Science, Bristol Medical School, Bristol, Bristol BS8 1TH, UK
| | - Heather Mason-Suares
- Laboratory for Molecular Medicine, Partners HealthCare Personalized Medicine, Cambridge, MA 02139, USA; Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Pathology, Harvard Medical School, Cambridge, MA 02115, USA
| | - Myriam Fornage
- The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Matthew Lebo
- Laboratory for Molecular Medicine, Partners HealthCare Personalized Medicine, Cambridge, MA 02139, USA; Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Pathology, Harvard Medical School, Cambridge, MA 02115, USA
| | - Nicholas J Timpson
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 1TH, UK; Population Health Science, Bristol Medical School, Bristol, Bristol BS8 1TH, UK; Avon Longitudinal Study of Parents and Children, Bristol BS8 1TH, UK
| | - Lee M Kaplan
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA; Obesity, Metabolism, and Nutrition Institute, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Sekar Kathiresan
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Division of Cardiology, Massachusetts General Hospital, Boston, MA 02114, USA; Cardiovascular Disease Initiative, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
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21
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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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22
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Wang W, Guo DY, Tao YX. Therapeutic strategies for diseases caused by loss-of-function mutations in G protein-coupled receptors. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 161:181-210. [DOI: 10.1016/bs.pmbts.2018.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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23
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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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24
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Herrfurth N, Volckmar AL, Peters T, Kleinau G, Müller A, Cetindag C, Schonnop L, Föcker M, Dempfle A, Wudy SA, Grant SFA, Reinehr T, Cousminer DL, Hebebrand J, Biebermann H, Hinney A. Relevance of polymorphisms in MC4R and BDNF in short normal stature. BMC Pediatr 2018; 18:278. [PMID: 30134862 PMCID: PMC6106737 DOI: 10.1186/s12887-018-1245-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 08/06/2018] [Indexed: 12/13/2022] Open
Abstract
Background Variation in genes of the leptinergic-melanocortinergic system influence both body weight and height. Because short normal stature (SNS) is characterized by reduced body height, delayed maturation and leanness, allelic variation of genes in this pathway are hypothesized to affect this common condition. Methods We analyzed the coding regions of LEP, MC4R, MRAP2 and BDNF in 185 children with SNS (height < 5th percentile) to search for non-synonymous and frameshift variants. For association studies (two-sided χ2-tests) population-based data sets (ExAC, EVS and KORA) were used. Cyclic AMP accumulation, cell surface expression, central expression and MAP kinase activation were assayed in vitro to determine the functional implications of identified variants. Results We detected eleven variants predicted to be protein-altering, four in MC4R, four in BDNF, and three in MRAP2. No variants were found in LEP. In vitro analysis implied reduced function for the MC4R variant p.Met215Ile. Loss-of-function is contrary to expectations based on obesity studies, and thus does not support that this variant is relevant for SNS. The minor SNP alleles at MC4R p.Val103Ile and BDNF p.Val66Met were nominally associated with SNS. Conclusion Taken together, although genes of the leptinergic-melanocortinergic system are important for normal growth, our data do not support the involvement of rare mutations in LEP, MC4R, MRAP2 or BDNF in short normal stature. Electronic supplementary material The online version of this article (10.1186/s12887-018-1245-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nikolas Herrfurth
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Anna-Lena Volckmar
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, 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, Essen, Germany
| | - Gunnar Kleinau
- Institute of Experimental Pediatric Endocrinology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Present Address: Group Protein X-ray Crystallography and Signal Transduction, Institute of Medical Physics and Biophysics, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Anne Müller
- Institute of Experimental Pediatric Endocrinology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Cigdem Cetindag
- Institute of Experimental Pediatric Endocrinology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Laura Schonnop
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Manuel Föcker
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Astrid Dempfle
- Institute of Medical Informatics and Statistics, Christian-Albrechts University Kiel, Kiel, Germany
| | - Stefan A Wudy
- Division of Pediatric Endocrinology and Diabetology, Center of Child and Adolescent Medicine, Giessen, Germany
| | - Struan F A Grant
- Divisions of Human Genetics and Endocrinology, Children's Hospital of Philadelphia Research Institute, Philadelphia, USA.,Department of Genetics, University of Pennsylvania, Philadelphia, USA
| | - Thomas Reinehr
- Department of Pediatric Endocrinology, Diabetes and Nutrition Medicine, Vestische Hospital for Children and Adolescents Datteln, University of Witten/Herdecke, Datteln, Germany
| | - Diana L Cousminer
- Divisions of Human Genetics and Endocrinology, Children's Hospital of Philadelphia Research Institute, Philadelphia, USA.,Department of Genetics, University of Pennsylvania, Philadelphia, USA
| | - Johannes Hebebrand
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Heike Biebermann
- Institute of Experimental Pediatric Endocrinology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Anke Hinney
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
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25
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Iepsen EW, Zhang J, Thomsen HS, Hansen EL, Hollensted M, Madsbad S, Hansen T, Holst JJ, Holm JC, Torekov SS. Patients with Obesity Caused by Melanocortin-4 Receptor Mutations Can Be Treated with a Glucagon-like Peptide-1 Receptor Agonist. Cell Metab 2018; 28:23-32.e3. [PMID: 29861388 DOI: 10.1016/j.cmet.2018.05.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/09/2018] [Accepted: 05/05/2018] [Indexed: 01/12/2023]
Abstract
Pathogenic mutations in the appetite-regulating melanocortin-4 receptor (MC4R) represent the most common cause of monogenic obesity with limited treatment options. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) cause weight loss by reducing appetite. We assessed the effect of the GLP-1 RA liraglutide 3.0 mg for 16 weeks in 14 obese individuals with pathogenic MC4R mutations (BMI 37.5 ± 6.8) and 28 matched control participants without MC4R mutation (BMI 36.8 ± 4.8). Liraglutide decreased body weight by 6.8 kg ± 1.8 kg in individuals with pathogenic MC4R mutations and by 6.1 kg ± 1.2 kg in control participants. Total body fat, waist circumference, and fasting and postprandial glucose concentrations similarly decreased in both groups. Thus, liraglutide induced an equal, clinically significant weight loss of 6% in both groups, indicating that the appetite-reducing effect of liraglutide is preserved in MC4R causal obesity and that liraglutide acts independently of the MC4R pathway. Thus, liraglutide could be an effective treatment of the most common form of monogenic obesity.
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Affiliation(s)
- Eva W Iepsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark; The Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Translational Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark.
| | - Jinyi Zhang
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark; The Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Translational Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Henrik S Thomsen
- Department of Radiology, Herlev University Hospital, Herlev 2730, Denmark
| | - Elizaveta L Hansen
- Department of Radiology, Herlev University Hospital, Herlev 2730, Denmark
| | - Mette Hollensted
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Hvidovre University Hospital, Hvidovre 2650, Denmark
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark; The Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Translational Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Jens-Christian Holm
- The Children's Obesity Clinic, Department of Pediatrics, Holbæk University Hospital, Holbæk 4300, Denmark
| | - Signe S Torekov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark; The Novo Nordisk Foundation Center for Basic Metabolic Research, Section for Translational Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark.
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26
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Lensing CJ, Freeman KT, Schnell SM, Speth RC, Zarth AT, Haskell-Luevano C. Developing a Biased Unmatched Bivalent Ligand (BUmBL) Design Strategy to Target the GPCR Homodimer Allosteric Signaling (cAMP over β-Arrestin 2 Recruitment) Within the Melanocortin Receptors. J Med Chem 2018; 62:144-158. [PMID: 29669202 DOI: 10.1021/acs.jmedchem.8b00238] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Understanding the functional relevance of G protein-coupled receptor (GPCR) homodimerization has been limited by the insufficient tools to assess asymmetric signaling occurring within dimers comprised of the same receptor type. We present unmatched bivalent ligands (UmBLs) to study the asymmetric function of melanocortin homodimers. UmBLs contain one agonist and one antagonist pharmacophore designed to target a melanocortin homodimer such that one receptor is occupied by an agonist and the other receptor by an antagonist pharmacophore. First-in-class biased UmBLs (BUmBLs) targeting the human melanocortin-4 receptor (hMC4R) were discovered. The BUmBLs displayed biased agonism by potently stimulating cAMP signaling (EC50 ∼ 2-6 nM) but minimally activating the β-arrestin recruitment pathway (≤55% maximum signal at 10 μM). To our knowledge, we report the first single-compound strategy to pharmacologically target melanocortin receptor allosteric signaling that occurs between homodimers that can be applied straightforwardly in vitro and in vivo to other GPCR systems.
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Affiliation(s)
- Cody J Lensing
- Department of Medicinal Chemistry and Institute for Translational Neuroscience , University of Minnesota , 308 Harvard Street SE , Minneapolis , Minnesota 55455 , United States
| | - Katie T Freeman
- Department of Medicinal Chemistry and Institute for Translational Neuroscience , University of Minnesota , 308 Harvard Street SE , Minneapolis , Minnesota 55455 , United States
| | - Sathya M Schnell
- Department of Medicinal Chemistry and Institute for Translational Neuroscience , University of Minnesota , 308 Harvard Street SE , Minneapolis , Minnesota 55455 , United States
| | - Robert C Speth
- College of Pharmacy , Nova Southeastern University , Fort Lauderdale , Florida 33328-2018 , United States.,Department of Pharmacology and Physiology , Georgetown University , Washington, D.C. 20057 , United States
| | - Adam T Zarth
- Department of Medicinal Chemistry and Institute for Translational Neuroscience , University of Minnesota , 308 Harvard Street SE , Minneapolis , Minnesota 55455 , United States.,Masonic Cancer Center , University of Minnesota , 2231 Sixth Street SE, 2-210 CCRB , Minneapolis , Minnesota 55455 , United States
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry and Institute for Translational Neuroscience , University of Minnesota , 308 Harvard Street SE , Minneapolis , Minnesota 55455 , United States
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Al-Najim W, le Roux CW, Docherty NG. Integrated insights into the role of alpha-melanocyte stimulatory hormone in the control of food intake and glycaemia. Peptides 2018; 100:243-248. [PMID: 29412826 DOI: 10.1016/j.peptides.2017.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 12/01/2017] [Accepted: 12/04/2017] [Indexed: 10/18/2022]
Abstract
Identifying peptide hormones with multipotent actions on both weight and glycaemia can have a significant impact on therapeutic options in the treatment of obesity and diabetes. This has been exemplified by recent advances involving pharmacological exploitation of glucagon-like peptide 1 biology. Herein, we summarise evidence supporting the potential candidacy in this light of alpha-melanocyte stimulatory hormone, an endogenous peptide hormone and a breakdown product of the neuropeptide pro-opiomelanocortin. We reference its well described central actions in the control of food intake and moreover highlight new data pointing to an important role for this peptide hormone in the periphery, in relation to glycaemic control.
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Affiliation(s)
- Werd Al-Najim
- Diabetes Complications Research Centre, Conway Institute, School of Medicine and Medical Sciences, University College Dublin, Ireland; Investigative Science, Imperial College London, UK
| | - Carel W le Roux
- Diabetes Complications Research Centre, Conway Institute, School of Medicine and Medical Sciences, University College Dublin, Ireland; Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden; Investigative Science, Imperial College London, UK
| | - Neil G Docherty
- Diabetes Complications Research Centre, Conway Institute, School of Medicine and Medical Sciences, University College Dublin, Ireland; Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden.
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Giuranna J, Diebels I, Hinney A. Polygene Varianten und Epigenetik bei Adipositas. MED GENET-BERLIN 2017. [DOI: 10.1007/s11825-017-0156-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Zusammenfassung
Hintergrund
Durch molekulargenetische Analysen wurde eine kleine Anzahl von Hauptgenen identifiziert, die Übergewicht (Body Mass Index, BMI ≥ 25 kg/m2) und Adipositas (BMI ≥ 30 kg/m2) bei Menschen mit bedingen können. Die zugrunde liegenden Mutationen sind selten. Die genetische Prädisposition zur Entwicklung einer Adipositas ist meist polygener Natur.
Ziel der Arbeit
Darstellung der polygenen Formen der Adipositas und epigenetischer Befunde.
Material und Methoden
Literaturübersicht.
Ergebnisse und Diskussion
Metaanalysen genomweiter Assoziationsstudien (GWAMA) haben bisher mehr als 100 Polygene oder polygene Loci identifiziert, die genomweit mit dem BMI assoziiert sind. Jedes einzelne Polygen leistet nur einen kleinen Beitrag zur Entwicklung einer Adipositas. Effektstärken liegen im Bereich von ca. 100 g bis 1,5 kg. Eine Reihe solcher prädisponierenden Genvarianten (Allele) findet sich bei adipösen Probanden. Allerdings tragen auch normalgewichtige und schlanke Individuen diese Allele, wenn auch in geringerer Frequenz. Diese Allele können durch statistische Analysen als Adipositas-Risikoallele identifiziert und validiert werden. Vor Kurzem haben sogenannte Cross-Disorder- und Cross-Phänotyp-Analysen zur Identifizierung von Genen geführt, die nicht allein durch Analysen der einzelnen Erkrankungen/Phänotypen nachgewiesen werden konnten. Funktionelle in-vitro- und in-vivo-Studien der GWAS-abgeleiteten Polygene könnten zu einem besseren Verständnis der molekulargenetischen Mechanismen der Körpergewichtsregulation führen. Erste genomweite Methylierungsmusteranalysen und Studien zu metastabilen Epiallelen tragen zudem zu einem besseren Verständnis der Pathomechanismen der Adipositas bei.
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Affiliation(s)
- Johanna Giuranna
- Aff1 0000 0001 2187 5445 grid.5718.b Klinik für Psychiatrie, Psychosomatik und Psychotherapie des Kindes- und Jugendalters, Universitätsklinikum Essen (AöR) Universität Duisburg-Essen Virchowstr. 171 45147 Essen Deutschland
| | - Inga Diebels
- Aff1 0000 0001 2187 5445 grid.5718.b Klinik für Psychiatrie, Psychosomatik und Psychotherapie des Kindes- und Jugendalters, Universitätsklinikum Essen (AöR) Universität Duisburg-Essen Virchowstr. 171 45147 Essen Deutschland
| | - Anke Hinney
- Aff1 0000 0001 2187 5445 grid.5718.b Klinik für Psychiatrie, Psychosomatik und Psychotherapie des Kindes- und Jugendalters, Universitätsklinikum Essen (AöR) Universität Duisburg-Essen Virchowstr. 171 45147 Essen Deutschland
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Evaluation of a melanocortin-4 receptor (MC4R) agonist (Setmelanotide) in MC4R deficiency. Mol Metab 2017; 6:1321-1329. [PMID: 29031731 PMCID: PMC5641599 DOI: 10.1016/j.molmet.2017.06.015] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 06/26/2017] [Accepted: 06/28/2017] [Indexed: 01/08/2023] Open
Abstract
Objective Pro-opiomelanocortin (POMC)-derived peptides act on neurons expressing the Melanocortin 4 receptor (MC4R) to reduce body weight. Setmelanotide is a highly potent MC4R agonist that leads to weight loss in diet-induced obese animals and in obese individuals with complete POMC deficiency. While POMC deficiency is very rare, 1–5% of severely obese individuals harbor heterozygous mutations in MC4R. We sought to assess the efficacy of Setmelanotide in human MC4R deficiency. Methods We studied the effects of Setmelanotide on mutant MC4Rs in cells and the weight loss response to Setmelanotide administration in rodent studies and a human clinical trial. We annotated the functional status of 369 published MC4R variants. Results In cells, we showed that Setmelanotide is significantly more potent at MC4R than the endogenous ligand alpha-melanocyte stimulating hormone and can disproportionally rescue signaling by a subset of severely impaired MC4R mutants. Wild-type rodents appear more sensitive to Setmelanotide when compared to MC4R heterozygous deficient mice, while MC4R knockout mice fail to respond. In a 28-day Phase 1b clinical trial, Setmelanotide led to weight loss in obese MC4R variant carriers. Patients with POMC defects upstream of MC4R show significantly more weight loss with Setmelanotide than MC4R deficient patients or obese controls. Conclusions Setmelanotide led to weight loss in obese people with MC4R deficiency; however, further studies are justified to establish whether Setmelanotide can elicit clinically meaningful weight loss in a subset of the MC4R deficient obese population.
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Yang Y, Harmon CM. Molecular signatures of human melanocortin receptors for ligand binding and signaling. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2436-2447. [PMID: 28478228 DOI: 10.1016/j.bbadis.2017.04.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 04/10/2017] [Accepted: 04/29/2017] [Indexed: 12/29/2022]
Abstract
Human melanocortin receptors (hMCRs) belong to the seven-transmembrane (TM) domain proteins. There are five hMCR subtypes and each of these receptor subtypes has different patterns of tissue expression and physiological function. The endogenous agonists for hMCRs are α-, β-, and γ-MSH and ACTH and endogenous antagonists are Agouti and AGRP which are the only known naturally occurring antagonists for the receptors. These peptides have their own profiles regarding the relative potency for specific hMCR subtype. Extensive studies have been performed to examine the molecular basis of the hMCRs for different ligand binding affinity and potency. Studies indicate that natural ligand α-MSH utilizes conserved amino acid residues for MCR specific binding (orthosteric binding) while synthetic ligands utilize non-conserved amino acid residues for receptor subtype specific binding (allosteric binding). ACTH is the only endogenous agonist for hMC2R and more amino acid residues at hMC2R are required for ACTH binding and signaling. HMCR computer modeling provides the detailed information of ligand and MCR interaction. This review provides the latest understanding of the molecular basis of the hMCRs for ligand binding and signaling. This article is part of a Special Issue entitled: Melanocortin Receptors - edited by Ya-Xiong Tao.
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Affiliation(s)
- Yingkui Yang
- Department of Surgery, State University of New York at Buffalo, Buffalo, NY 14203, United States.
| | - Carroll M Harmon
- Department of Surgery, State University of New York at Buffalo, Buffalo, NY 14203, United States
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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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Huang H, Wang W, Tao YX. Pharmacological chaperones for the misfolded melanocortin-4 receptor associated with human obesity. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2496-2507. [PMID: 28284973 DOI: 10.1016/j.bbadis.2017.03.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 01/01/2023]
Abstract
The melanocortin-4 receptor (MC4R) plays a vital role in regulating energy homeostasis. Mutations in the MC4R cause early-onset severe obesity. The majority of loss of function MC4R mutants are retained intracellularly, many of which are not terminally misfolded and can be stabilized and targeted to the plasma membrane by different chaperones. Some of the mutants might be functional once coaxed to the cell surface. Molecular chaperones and chemical chaperones correct the misfolding of some mutant MC4Rs. However, their therapeutic application is very limited due to their non-specific mechanism of action and, for chemical chaperone, high dosage needed to be effective. Several pharmacological chaperones have been identified for the MC4R and Ipsen 5i and Ipsen 17 are the most potent and efficacious. Here we provide a comprehensive review on how different approaches have been applied to rescue misfolded MC4R mutants. This article is part of a Special Issue entitled: Melanocortin Receptors - edited by Ya-Xiong Tao.
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Affiliation(s)
- Hui Huang
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States
| | - Wei Wang
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States.
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Bonnefond A, Keller R, Meyre D, Stutzmann F, Thuillier D, Stefanov DG, Froguel P, Horber FF, Kral JG. Eating Behavior, Low-Frequency Functional Mutations in the Melanocortin-4 Receptor (MC4R) Gene, and Outcomes of Bariatric Operations: A 6-Year Prospective Study. Diabetes Care 2016; 39:1384-92. [PMID: 27222505 DOI: 10.2337/dc16-0115] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/02/2016] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Data on the effects of eating behavior and genetics on outcomes of gastrointestinal surgery for diabesity have been sparse, often flawed, and controversial. We aimed to assess long-term outcomes of bariatric operations in patients characterized for eating behavior and rare mutations in the melanocortin-4 receptor (MC4R) gene, which is strongly implicated in energy balance. RESEARCH DESIGN AND METHODS Between 1996 and 2005, 1,264 severely obese Swiss patients underwent current laparoscopic adjustable gastric banding, gastroduodenal bypass, or a hybrid operation. Of these, 872 patients were followed for a minimum of 6 years and were screened for MC4R mutations. Using regression models, we studied relationships between eating behavior and MC4R mutations and postoperative weight loss, complications, and reoperations after 6 years. RESULTS At baseline, rare functional MC4R mutation carriers exhibited a significantly higher prevalence of binge eating disorder (BED) or loss-of-control eating independent of age, sex, and BMI. Six years after bariatric surgery, the mutation carriers had more major complications than wild-type subjects independent of age, baseline BMI, sex, operation type, and weight loss. Furthermore, high baseline BMI, male sex, BED, and functional MC4R mutations were independent predictors of higher reoperation rates. CONCLUSIONS Sequencing of MC4R and eating typology, combined with stratification for sex and baseline BMI, might significantly improve patient allocation to banding or bypass operations for diabesity as well as reduce both complication and reoperation rates.
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Affiliation(s)
- Amélie Bonnefond
- CNRS UMR 8199, Lille Pasteur Institute, Lille, France Lille University, Lille, France European Genome Institute for Diabetes, FR 3508, Lille, France Department of Genomics of Common Disease, School of Public Health, Hammersmith Hospital, Imperial College London, London, U.K
| | - Ramsi Keller
- Department of Internal Medicine, Landesspital Liechtenstein, Vaduz, Liechtenstein Dr. Horber Adipositas Stiftung, Zurich, Switzerland
| | - David Meyre
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Fanny Stutzmann
- CNRS UMR 8199, Lille Pasteur Institute, Lille, France Lille University, Lille, France European Genome Institute for Diabetes, FR 3508, Lille, France
| | - Dorothée Thuillier
- CNRS UMR 8199, Lille Pasteur Institute, Lille, France Lille University, Lille, France European Genome Institute for Diabetes, FR 3508, Lille, France
| | - Dimitre G Stefanov
- Scientific Computing Center and Departments of Surgery, Medicine, and Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY
| | - Philippe Froguel
- CNRS UMR 8199, Lille Pasteur Institute, Lille, France Lille University, Lille, France European Genome Institute for Diabetes, FR 3508, Lille, France Department of Genomics of Common Disease, School of Public Health, Hammersmith Hospital, Imperial College London, London, U.K.
| | - Fritz F Horber
- Department of Internal Medicine, Landesspital Liechtenstein, Vaduz, Liechtenstein Dr. Horber Adipositas Stiftung, Zurich, Switzerland University of Bern, Bern, Switzerland
| | - John G Kral
- Scientific Computing Center and Departments of Surgery, Medicine, and Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY
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Todorovic A, Ericson MD, Palusak RD, Sorensen NB, Wood MS, Xiang Z, Haskell-Luevano C. Comparative Functional Alanine Positional Scanning of the α-Melanocyte Stimulating Hormone and NDP-Melanocyte Stimulating Hormone Demonstrates Differential Structure-Activity Relationships at the Mouse Melanocortin Receptors. ACS Chem Neurosci 2016; 7:984-94. [PMID: 27135265 PMCID: PMC5596636 DOI: 10.1021/acschemneuro.6b00098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The melanocortin system has been implicated in the regulation of various physiological functions including melanogenesis, steroidogenesis, energy homeostasis, and feeding behavior. Five melanocortin receptors have been identified to date and belong to the family of G protein-coupled receptors (GPCR). Post-translational modification of the proopiomelanocortin (POMC) prohormone leads to the biosynthesis of the endogenous melanocortin agonists, including α-melanocyte stimulating hormone (α-MSH), β-MSH, γ-MSH, and adrenocorticotropic hormone (ACTH). All the melanocortin agonists derived from the POMC prohormone contain a His-Phe-Arg-Trp tetrapeptide sequence that has been implicated in eliciting the pharmacological responses at the melanocortin receptors. Herein, an alanine (Ala) positional scan is reported for the endogenous α-MSH ligand and the synthetic, more potent, NDP-MSH peptide (Ac-Ser(1)-Tyr(2)-Ser(3)-Nle(4)-Glu(5)-His(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-Lys(11)-Pro(12)-Val(13)-NH2) at the cloned mouse melanocortin receptors to test the assumption that the structure-activity relationships of one ligand would apply to the other. Several residues outside of the postulated pharmacophore altered potency at the melanocortin receptors, most notably the 1560-, 37-, and 15-fold potency loss when the Glu(5) position of α-MSH was substituted with Ala at the mMC1R, mMC3R, and mMC4R, respectively. Importantly, the altered potencies due to Ala substitutions in α-MSH did not necessarily correlate with equivalent Ala substitutions in NDP-MSH, indicating that structural modifications and corresponding biological activities in one of these melanocortin ligands may not be predictive for the other agonist.
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Affiliation(s)
- Aleksandar Todorovic
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610
| | - Mark D. Ericson
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455
| | - Ryan D. Palusak
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610
| | - Nicholas B. Sorensen
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610
| | - Michael S. Wood
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610
| | - Zhimin Xiang
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455
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Polák E, Vitáriušová E, Celec P, Pribilincová Z, Košťálová Ľ, Hlavatá A, Kovács L, Kádaši Ľ. The prevalence of melanocortin-4 receptor gene mutations in Slovak obese children and adolescents. J Pediatr Endocrinol Metab 2016; 29:55-61. [PMID: 26244670 DOI: 10.1515/jpem-2015-0015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 04/24/2015] [Indexed: 01/25/2023]
Abstract
Melanocortin-4 receptor (MC4R) deficiency is the most frequent monogenic form of obesity. The contribution of MC4R mutations to the Slovak population has not been investigated as yet. We screened the coding sequence of the MC4R gene in a cohort of 210 Slovak obese children and adolescents. We identified four different mutations in four patients, giving a mutation detection rate of 0.95%. Of these, three were missense mutations previously identified and characterized by other research groups (p.R7C, p.S127L and p. R305W, respectively). One was a novel nonsense mutation p.W174* detected in a severely obese 7-year-old boy. This mutation was further analyzed in family segregation analysis and exhibited variable penetrance. Two known amino acid polymorphisms (p.V103I and p.I251L) were also identified in seven subjects of our cohort group. We also performed multifactorial statistical analysis to determine the influence of genotypes on standard biochemical blood markers. No significant influence was observed in carriers of DNA variants on tested parameters. We conclude that rare heterozygous MC4R mutations contribute to the onset of obesity only in a few cases in the Slovak population.
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Dar R, Rasool S, Zargar AH, Jan TR, Andrabi KI. Polymorphic analysis of MC4R gene in ethnic Kashmiri population with type 2 diabetes. Int J Diabetes Dev Ctries 2015. [DOI: 10.1007/s13410-015-0454-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Logan M, Van der Merwe MT, Dodgen TM, Myburgh R, Eloff A, Alessandrini M, Pepper MS. Allelic variants of the Melanocortin 4 receptor (MC4R) gene in a South African study group. Mol Genet Genomic Med 2015; 4:68-76. [PMID: 26788538 PMCID: PMC4707032 DOI: 10.1002/mgg3.180] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 09/09/2015] [Accepted: 09/11/2015] [Indexed: 12/20/2022] Open
Abstract
Obesity is a global epidemic that results in significant morbidity and mortality. Mutations in the melanocortin 4 receptor (MC4R) gene, which codes for a G-protein-coupled receptor responsible for postprandial satiety signaling, have been associated with monogenic obesity. The prevalence of obesity is on the increase in South Africa, and it is hypothesized that mutations in MC4R are a contributing factor. The aim of this study was to perform a retrospective assessment of the relationship between allelic variants of MC4R and BMI in a South African study cohort. DNA was isolated from a demographically representative cohort of 297 individuals and the entire MC4R gene sequenced by Sanger sequencing. Eight previously reported MC4R variants were identified in 42 of the 297 (14.1%) study participants. The most frequently observed MC4R alleles were V103I (4.0%), I170V (1.5%), and I198I (1.2%), while the remaining five variants together constituted 1.18%. Five compound heterozygotes were also detected. Although MC4R variants were rare, the majority of variation was observed in individuals of Black African ancestry. No statistically significant associations with BMI were reported. Given that lifestyle interventions have limited success in decreasing obesity, there is an urgent need to perform large-scale population studies to further elucidate the molecular underpinnings of this disease.
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Affiliation(s)
- Murray Logan
- Department of ImmunologyUniversity of PretoriaPretoriaSouth Africa; Faculty of Health SciencesInstitute for Cellular and Molecular MedicineUniversity of PretoriaPretoriaSouth Africa
| | | | - Tyren M Dodgen
- Faculty of Health SciencesInstitute for Cellular and Molecular MedicineUniversity of PretoriaPretoriaSouth Africa; Department of PharmacologyUniversity of PretoriaPretoriaSouth Africa
| | - Renier Myburgh
- Department of ImmunologyUniversity of PretoriaPretoriaSouth Africa; Faculty of Health SciencesInstitute for Cellular and Molecular MedicineUniversity of PretoriaPretoriaSouth Africa
| | - Arinda Eloff
- Department of ImmunologyUniversity of PretoriaPretoriaSouth Africa; Faculty of Health SciencesInstitute for Cellular and Molecular MedicineUniversity of PretoriaPretoriaSouth Africa
| | - Marco Alessandrini
- Department of ImmunologyUniversity of PretoriaPretoriaSouth Africa; Faculty of Health SciencesInstitute for Cellular and Molecular MedicineUniversity of PretoriaPretoriaSouth Africa
| | - Michael S Pepper
- Department of ImmunologyUniversity of PretoriaPretoriaSouth Africa; Faculty of Health SciencesInstitute for Cellular and Molecular MedicineUniversity of PretoriaPretoriaSouth Africa; Department of Genetic Medicine and DevelopmentFaculty of MedicineUniversity of GenevaGenevaSwitzerland
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Molden BM, Cooney KA, West K, Van Der Ploeg LHT, Baldini G. Temporal cAMP Signaling Selectivity by Natural and Synthetic MC4R Agonists. Mol Endocrinol 2015; 29:1619-33. [PMID: 26418335 DOI: 10.1210/me.2015-1071] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The melanocortin-4 receptor (MC4R) is a G protein-coupled receptor expressed in the brain, where it controls energy balance through pathways including α-melanocyte-stimulating hormone (α-MSH)-dependent signaling. We have reported that the MC4R can exist in an active conformation that signals constitutively by increasing cAMP levels in the absence of receptor desensitization. We asked whether synthetic MC4R agonists differ in their ability to increase intracellular cAMP over time in Neuro2A cells expressing endogenous MC4R and exogenous, epitope-tagged hemagglutinin-MC4R-green fluorescent protein. By analyzing intracellular cAMP in a temporally resolved Förster resonance energy transfer assay, we show that withdrawal of α-MSH leads to a quick reversal of cAMP induction. By contrast, the synthetic agonist melanotan II (MTII) induces a cAMP signal that persists for at least 1 hour after removal of MTII from the medium and cannot be antagonized by agouti related protein. Similarly, in mHypoE-42 immortalized hypothalamic neurons, MTII, but not α-MSH, induced persistent AMP kinase signal, which occurs downstream of increased cAMP. By using a fluorescence recovery after photobleaching assay, it appears that the receptor exposed to MTII continues to signal after being internalized. Similar to MTII, the synthetic MC4R agonists, THIQ and BIM-22511, but not LY2112688, induced prolonged cAMP signaling after agonist withdrawal. However, agonist-exposed MC4R desensitized to the same extent, regardless of the ligand used and regardless of differences in receptor intracellular retention kinetics. In conclusion, α-MSH and LY2112688, when compared with MTII, THIQ, and BIM-22511, vary in the duration of the acute cAMP response, showing distinct temporal signaling selectivity, possibly linked to specific cell compartments from which cAMP signals may originate.
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Affiliation(s)
- Brent M Molden
- Department of Biochemistry and Molecular Biology (B.M.M., K.A.C., K.W., G.B.), University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199; and Rhythm Pharmaceuticals, Inc (L.H.T.V.D.P.), Boston, Massachusetts 02116
| | - Kimberly A Cooney
- Department of Biochemistry and Molecular Biology (B.M.M., K.A.C., K.W., G.B.), University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199; and Rhythm Pharmaceuticals, Inc (L.H.T.V.D.P.), Boston, Massachusetts 02116
| | - Kirk West
- Department of Biochemistry and Molecular Biology (B.M.M., K.A.C., K.W., G.B.), University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199; and Rhythm Pharmaceuticals, Inc (L.H.T.V.D.P.), Boston, Massachusetts 02116
| | - Lex H T Van Der Ploeg
- Department of Biochemistry and Molecular Biology (B.M.M., K.A.C., K.W., G.B.), University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199; and Rhythm Pharmaceuticals, Inc (L.H.T.V.D.P.), Boston, Massachusetts 02116
| | - Giulia Baldini
- Department of Biochemistry and Molecular Biology (B.M.M., K.A.C., K.W., G.B.), University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199; and Rhythm Pharmaceuticals, Inc (L.H.T.V.D.P.), Boston, Massachusetts 02116
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Abstract
The global rise in the prevalence of obesity and associated co-morbidities such as type 2 diabetes, cardiovascular disease, and cancer represents a major public health concern. The biological response to increased consumption of palatable foods or a reduction in energy expenditure is highly variable between individuals. A more detailed mechanistic understanding of the molecular, physiological, and behavioral pathways involved in the development of obesity in susceptible individuals is critical for identifying effective mechanism-based preventative and therapeutic interventions.
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Affiliation(s)
- Agatha A van der Klaauw
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - I Sadaf Farooqi
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
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40
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Manning S, Pucci A, Batterham RL. Roux-en-Y gastric bypass: effects on feeding behavior and underlying mechanisms. J Clin Invest 2015; 125:939-48. [PMID: 25729850 DOI: 10.1172/jci76305] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bariatric surgery is the most effective treatment for severe obesity, producing marked sustained weight loss with associated reduced morbidity and mortality. Roux-en-Y gastric bypass surgery (RYGBP), the most commonly performed procedure, was initially viewed as a hybrid restrictive-malabsorptive procedure. However, over the last decade, it has become apparent that alternative physiologic mechanisms underlie its beneficial effects. RYGBP-induced altered feeding behavior, including reduced appetite and changes in taste/food preferences, is now recognized as a key driver of the sustained postoperative weight loss. The brain ultimately determines feeding behavior, and here we review the mechanisms by which RYGBP may affect central appetite-regulating pathways.
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41
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Tao YX. Constitutive activity in melanocortin-4 receptor: biased signaling of inverse agonists. ADVANCES IN PHARMACOLOGY 2015; 70:135-54. [PMID: 24931195 DOI: 10.1016/b978-0-12-417197-8.00005-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The melanocortin-4 receptor (MC4R) is a critical regulator of energy homeostasis, including both energy intake and energy expenditure. It mediates the actions of a number of hormones on energy balance. The endogenous ligands for MC4R include peptide agonists derived from processing of proopiomelanocortin and the antagonist Agouti-related peptide (AgRP). Wild-type MC4R has some basal (constitutive) activity. Naturally occurring and laboratory-generated mutations have been identified, which results in either increased or decreased basal activities. Impaired basal signaling has been suggested to be a cause of dysregulated energy homeostasis and early-onset obesity, although several constitutively active mutations have also been identified from obese patients. AgRP and several small-molecule antagonists have been shown to be inverse agonists in the Gs-cAMP pathway. However, in the extracellular signal-regulated kinase (ERK) 1/2 pathway, we showed that these inverse agonists are potent agonists, demonstrating convincingly that they are biased ligands. We also showed that some mutations that do not cause constitutive activation in the Gs-cAMP pathway cause constitutive activation in the ERK1/2 pathway, suggesting that they are biased receptors. The physiological and potential pathophysiological relevance of the biased constitutive signaling in MC4R and therapeutic potential remain to be investigated.
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA.
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42
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Testa C, Scrima M, Grimaldi M, D'Ursi AM, Dirain ML, Lubin-Germain N, Singh A, Haskell-Luevano C, Chorev M, Rovero P, Papini AM. 1,4-disubstituted-[1,2,3]triazolyl-containing analogues of MT-II: design, synthesis, conformational analysis, and biological activity. J Med Chem 2014; 57:9424-34. [PMID: 25347033 PMCID: PMC4255721 DOI: 10.1021/jm501027w] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Side chain-to-side chain cyclizations
represent a strategy to select
a family of bioactive conformations by reducing the entropy and enhancing
the stabilization of functional ligand-induced receptor conformations.
This structural manipulation contributes to increased target specificity,
enhanced biological potency, improved pharmacokinetic properties,
increased functional potency, and lowered metabolic susceptibility.
The CuI-catalyzed azide–alkyne 1,3-dipolar Huisgen’s
cycloaddition, the prototypic click reaction, presents a promising
opportunity to develop a new paradigm for an orthogonal bioorganic
and intramolecular side chain-to-side chain cyclization. In fact,
the proteolytic stable 1,4- or 4,1-disubstituted [1,2,3]triazolyl
moiety is isosteric with the peptide bond and can function as a surrogate
of the classical side chain-to-side chain lactam forming bridge. Herein
we report the design, synthesis, conformational analysis, and functional
biological activity of a series of i-to-i+5 1,4- and 4,1-disubstituted
[1,2,3]triazole-bridged cyclopeptides derived from MT-II, the homodetic
Asp5 to Lys10 side chain-to-side chain bridged
heptapeptide, an extensively studied agonist of melanocortin receptors.
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Affiliation(s)
- Chiara Testa
- Laboratoire SOSCO & PeptLab@UCP, EA4505, University of Cergy-Pontoise , 5 mail Gay-Lussac, Neuville sur Oise, F-95031 Cergy-Pontoise Cedex, France
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43
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Singh A, Dirain ML, Wilczynski A, Chen C, Gosnell BA, Levine AS, Edison AS, Haskell-Luevano C. Synthesis, biophysical, and pharmacological evaluation of the melanocortin agonist AST3-88: modifications of peptide backbone at Trp 7 position lead to a potent, selective, and stable ligand of the melanocortin 4 receptor (MC4R). ACS Chem Neurosci 2014; 5:1020-31. [PMID: 25141170 PMCID: PMC4198065 DOI: 10.1021/cn5000953] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
![]()
The
melanocortin-3 (MC3R) and melanocortin-4 (MC4R) receptors are
expressed in the brain and are implicated in the regulation of food
intake and energy homeostasis. The endogenous agonist ligands for
these receptors (α-, β-, γ-MSH and ACTH) are linear
peptides with limited receptor subtype selectivity and metabolic stability,
thus minimizing their use as probes to characterize the overlapping
pharmacological and physiological functions of the melanocortin receptor
subtypes. In the present study, an engineered template, in which the
peptide backbone was modified by a heterocyclic reverse turn mimetic
at the Trp7 residue, was synthesized using solid phase
peptide synthesis and characterized by a β-galactosidase cAMP
based reporter gene assay. The functional assay identified a ∼5
nM mouse MC4R agonist (AST3-88) with more than 50-fold selectivity
over the mMC3R. Biophysical studies (2D 1H NMR spectroscopy
and molecular dynamics) of AST3-88 identified a type VIII β-turn
secondary structure spanning the pharmacophore domain stabilized by
the intramolecular interactions between the side chains of the His
and Trp residues. Enzymatic studies of AST3-88 revealed enhanced stability
of AST3-88 over the α-MSH endogenous peptide in rat serum. Upon
central administration of AST3-88 into rats, a decreased food intake
response was observed. This is the first study to probe the in vivo
physiological activity of this engineered peptide-heterocycle template.
These findings advance the present knowledge of pharmacophore design
for potent, selective, and metabolically stable melanocortin ligands.
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Affiliation(s)
- Anamika Singh
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | | | | | | | | | | | | | - Carrie Haskell-Luevano
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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Abstract
Heritability of obesity and body weight variation is high. Molecular genetic studies have led to the identification of mutations in a few genes, with a major effect on obesity (major genes and monogenic forms). Analyses of these genes have helped to unravel important pathways and have created a more profound understanding of body weight regulation. For most individuals, a polygenic basis is relevant for the genetic predisposition to obesity. Small effect sizes are conveyed by the polygenic variants. Hence, only if a number of these variants is harboured, a sizeable phenotypic effect is detectable. Most, if not all, of the genes relevant to weight regulation are expressed in the hypothalamus. This underscores the major role of this region of the brain in body weight regulation.
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Affiliation(s)
- Anke Hinney
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, Essen, Germany.
| | - Anna-Lena Volckmar
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, Essen, Germany.
| | - Jochen Antel
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, Essen, Germany.
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45
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Haslach EM, Huang H, Dirain M, Debevec G, Geer P, Santos RG, Giulianotti MA, Pinilla C, Appel JR, Doering SR, Walters MA, Houghten RA, Haskell-Luevano C. Identification of tetrapeptides from a mixture based positional scanning library that can restore nM full agonist function of the L106P, I69T, I102S, A219V, C271Y, and C271R human melanocortin-4 polymorphic receptors (hMC4Rs). J Med Chem 2014; 57:4615-28. [PMID: 24517312 PMCID: PMC4324447 DOI: 10.1021/jm500064t] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Human obesity has been linked to genetic factors and single nucleotide polymorphisms (SNPs). Melanocortin-4 receptor (MC4R) SNPs have been associated with up to 6% frequency in morbidly obese children and adults. A potential therapy for individuals possessing such genetic modifications is the identification of molecules that can restore proper receptor signaling and function. These compounds could serve as personalized medications improving quality of life issues as well as alleviating diseases symptoms associated with obesity including type 2 diabetes. Several hMC4 SNP receptors have been pharmacologically characterized in vitro to have a decreased, or a lack of response, to endogenous agonists such as α-, β-, and γ2-melanocyte stimulating hormones (MSH) and adrenocorticotropin hormone (ACTH). Herein we report the use of a mixture based positional scanning combinatorial tetrapeptide library to discover molecules with nM full agonist potency and efficacy to the L106P, I69T, I102S, A219V, C271Y, and C271R hMC4Rs. The most potent compounds at all these hMC4R SNPs include Ac-His-(pI)DPhe-Tic-(pNO2)DPhe-NH2, Ac-His-(pCl)DPhe-Tic-(pNO2)DPhe-NH2, Ac-His-(pCl)DPhe-Arg-(pI)Phe-NH2, and Ac-Arg-(pCl)DPhe-Tic-(pNO2)DPhe-NH2, revealing new ligand pharmacophore models for melanocortin receptor drug design strategies.
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Affiliation(s)
- Erica M Haslach
- Department of Pharmacodynamics, University of Florida , Gainesville, Florida 32610, United States
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46
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Evans DS, Calton MA, Kim MJ, Kwok PY, Miljkovic I, Harris T, Koster A, Liu Y, Tranah GJ, Ahituv N, Hsueh WC, Vaisse C. Genetic association study of adiposity and melanocortin-4 receptor (MC4R) common variants: replication and functional characterization of non-coding regions. PLoS One 2014; 9:e96805. [PMID: 24820477 PMCID: PMC4018404 DOI: 10.1371/journal.pone.0096805] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 04/11/2014] [Indexed: 11/29/2022] Open
Abstract
Common genetic variants 3' of MC4R within two large linkage disequilibrium (LD) blocks spanning 288 kb have been associated with common and rare forms of obesity. This large association region has not been refined and the relevant DNA segments within the association region have not been identified. In this study, we investigated whether common variants in the MC4R gene region were associated with adiposity-related traits in a biracial population-based study. Single nucleotide polymorphisms (SNPs) in the MC4R region were genotyped with a custom array and a genome-wide array and associations between SNPs and five adiposity-related traits were determined using race-stratified linear regression. Previously reported associations between lower BMI and the minor alleles of rs2229616/Val103Ile and rs52820871/Ile251Leu were replicated in white female participants. Among white participants, rs11152221 in a proximal 3' LD block (closer to MC4R) was significantly associated with multiple adiposity traits, but SNPs in a distal 3' LD block (farther from MC4R) were not. In a case-control study of severe obesity, rs11152221 was significantly associated. The association results directed our follow-up studies to the proximal LD block downstream of MC4R. By considering nucleotide conservation, the significance of association, and proximity to the MC4R gene, we identified a candidate MC4R regulatory region. This candidate region was sequenced in 20 individuals from a study of severe obesity in an attempt to identify additional variants, and the candidate region was tested for enhancer activity using in vivo enhancer assays in zebrafish and mice. Novel variants were not identified by sequencing and the candidate region did not drive reporter gene expression in zebrafish or mice. The identification of a putative insulator in this region could help to explain the challenges faced in this study and others to link SNPs associated with adiposity to altered MC4R expression.
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Affiliation(s)
- Daniel S. Evans
- California Pacific Medical Center Research Institute, San Francisco, California, United States of America
| | - Melissa A. Calton
- Diabetes Center and Department of Medicine, University of California, San Francisco, California, United States of America
| | - Mee J. Kim
- Department of Bioengineering and Therapeutic Sciences and Institute for Human Genetics, University of California, San Francisco, California, United States of America
| | - Pui-Yan Kwok
- Cardiovascular Research Institute, Institute for Human Genetics, and Department of Dermatology, University of California, San Francisco, California, United States of America
| | - Iva Miljkovic
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Tamara Harris
- National Institute on Aging, Bethesda, Maryland, United States of America
| | - Annemarie Koster
- National Institute on Aging, Bethesda, Maryland, United States of America
| | - Yongmei Liu
- Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest University, Winston-Salem, North Carolina, United States of America
| | - Gregory J. Tranah
- California Pacific Medical Center Research Institute, San Francisco, California, United States of America
| | - Nadav Ahituv
- Department of Bioengineering and Therapeutic Sciences and Institute for Human Genetics, University of California, San Francisco, California, United States of America
| | - Wen-Chi Hsueh
- Diabetes Center and Department of Medicine, University of California, San Francisco, California, United States of America
| | - Christian Vaisse
- Diabetes Center and Department of Medicine, University of California, San Francisco, California, United States of America
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47
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Moore BS, Mirshahi UL, Yost EA, Stepanchick AN, Bedrin MD, Styer AM, Jackson KK, Still CD, Breitwieser GE, Gerhard GS, Carey DJ, Mirshahi T. Long-term weight-loss in gastric bypass patients carrying melanocortin 4 receptor variants. PLoS One 2014; 9:e93629. [PMID: 24705671 PMCID: PMC3976318 DOI: 10.1371/journal.pone.0093629] [Citation(s) in RCA: 34] [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: 12/18/2013] [Accepted: 02/06/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The melanocortin 4 receptor (MC4R) critically regulates feeding and satiety. Rare variants in MC4R are predominantly found in obese individuals. Though some rare variants in MC4R discovered in patients have defects in localization, ligand binding and signaling to cAMP, many have no recognized defects. SUBJECTS/METHODS In our cohort of 1433 obese subjects that underwent Roux-en-Y Gastric Bypass (RYGB) surgery, we found fifteen variants of MC4R. We matched rare variant carriers to patients with the MC4R reference alleles for gender, age, starting BMI and T2D to determine the variant effect on weight-loss post-RYGB. In vitro, we determined expression of mutant receptors by ELISA and western blot, and cAMP production by microscopy. RESULTS While carrying a rare MC4R allele is associated with obesity, carriers of rare variants exhibited comparable weight-loss after RYGB to non-carriers. However, subjects carrying three of these variants, V95I, I137T or L250Q, lost less weight after surgery. In vitro, the R305Q mutation caused a defect in cell surface expression while only the I137T and C326R mutations showed impaired cAMP signaling. Despite these apparent differences, there was no correlation between in vitro signaling and pre- or post-surgery clinical phenotype. CONCLUSIONS These data suggest that subtle differences in receptor signaling conferred by rare MC4R variants combined with additional factors predispose carriers to obesity. In the absence of complete MC4R deficiency, these differences can be overcome by the powerful weight-reducing effects of bariatric surgery. In a complex disorder such as obesity, genetic variants that cause subtle defects that have cumulative effects can be overcome after appropriate clinical intervention.
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Affiliation(s)
- Bryn S. Moore
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Uyenlinh L. Mirshahi
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Evan A. Yost
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Ann N. Stepanchick
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Michael D. Bedrin
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Amanda M. Styer
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Kathryn K. Jackson
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Christopher D. Still
- Geisinger Obesity Institute, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Gerda E. Breitwieser
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Glenn S. Gerhard
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - David J. Carey
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
| | - Tooraj Mirshahi
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania, United States of America
- Geisinger Obesity Institute, Geisinger Clinic, Danville, Pennsylvania, United States of America
- * E-mail:
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48
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Malzahn D, Müller-Nurasyid M, Heid IM, Wichmann HE, Bickeböller H. Controversial association results for INSIG2 on body mass index may be explained by interactions with age and with MC4R. Eur J Hum Genet 2014; 22:1217-24. [PMID: 24518831 DOI: 10.1038/ejhg.2014.3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 12/17/2013] [Accepted: 12/30/2013] [Indexed: 12/14/2022] Open
Abstract
Among the single-nucleotide polymorphisms (SNPs) previously reported to be associated with body mass index (BMI) and obesity, we focus on a common risk variant rs7566605 upstream of the insulin-induced gene 2 (INSIG2) gene and a rare protective variant rs2229616 on the melanocortin-4 receptor (MC4R) gene. INSIG2 is involved in adipogenesis and MC4R effects hormonal appetite control in response to the amount of adipose tissue. The influence of rs2229616 (MC4R) on BMI and obesity has been confirmed repeatedly and insight into the underlying mechanism provided. However, a main effect of rs7566605 (INSIG2) is under debate because of inconsistent replications of association. Interaction of rs7566605 with age may offer an explanation. SNP-age and SNP-SNP interaction models were tested on independent individuals from three population-based longitudinal cohorts, restricting the analysis to an observed age of 25-74 years. KORA S3/F3, KORA S4/F4 (Augsburg, Germany, 1994-2005, 1999-2008), and Framingham-Offspring data (Framingham, USA, 1971-2001) were analysed, with a total sample size of N=6926 in the joint analysis. The effect of interaction between rs7566605 and age on BMI and obesity status is significant and consistent across studies. This new evidence for rs7566605 (INSIG2) complements previous research. In addition, the interaction effect of rs7566605 with the MC4R variant rs2229616 on BMI was observed. This effect size was three times larger than that in a previously reported single-locus main effect of rs2229616. This leads to the conclusion that SNP-age or SNP-SNP interactions can mask genetic effects for complex diseases if left unaccounted for.
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Affiliation(s)
- Dörthe Malzahn
- Department of Genetic Epidemiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Martina Müller-Nurasyid
- 1] Department of Medicine I, University Hospital Grosshadern, Ludwig-Maximilians-University, Munich, Germany [2] Institute of Medical Informatics, Biometry and Epidemiology, Chair of Epidemiology and Chair of Genetic Epidemiology, Ludwig-Maximilians-University, Neuherberg, Germany [3] Institute of Genetic Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Iris M Heid
- 1] Institute of Genetic Epidemiology, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany [2] Department of Genetic Epidemiology, University of Regensburg, Regensburg, Germany
| | - H-Erich Wichmann
- 1] Institute of Epidemiology I, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany [2] Institute of Medical Informatics, Biometry and Epidemiology, Chair of Epidemiology, Ludwig-Maximilians-University, Munich, Germany [3] Klinikum Großhadern, Munich, Germany
| | | | - Heike Bickeböller
- Department of Genetic Epidemiology, University Medical Center, Georg-August-University, Göttingen, Germany
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49
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Rovite V, Petrovska R, Vaivade I, Kalnina I, Fridmanis D, Zaharenko L, Peculis R, Pirags V, Schioth HB, Klovins J. The role of common and rare MC4R variants and FTO polymorphisms in extreme form of obesity. Mol Biol Rep 2014; 41:1491-500. [PMID: 24385306 DOI: 10.1007/s11033-013-2994-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Accepted: 12/24/2013] [Indexed: 11/30/2022]
Abstract
Melanocortin 4 receptor (MC4R) is an important regulator of food intake and number of studies report genetic variations influencing the risk of obesity. Here we explored the role of common genetic variation from MC4R locus comparing with SNPs from gene FTO locus, as well as the frequency and functionality of rare MC4R mutations in cohort of 380 severely obese individuals (BMI > 39 kg/m(2)) and 380 lean subjects from the Genome Database of Latvian Population (LGDB). We found correlation for two SNPs--rs11642015 and rs62048402 in the fat mass and obesity-associated protein (FTO) with obesity but no association was detected for rs17782313 located in the MC4R locus in these severely obese individuals. We sequenced the whole gene MC4R coding region in all study subjects and found five previously known heterozygous non-synonymous substitutions V103I, I121T, S127L, V166I and I251L. Expression in mammalian cells showed that the S127L, V166I and double V103I/S127L mutant receptors had significantly decreased quantity at the cell surface compared to the wild type MC4R. We carried out detailed functional analysis of V166I that demonstrated that, despite low abundance in plasma membrane, the V166I variant has lower EC50 value upon αMSH activation than the wild type receptor, while the level of AGRP inhibition was decreased, implying that V166I cause hyperactive satiety signalling. Overall, this study suggest that S127L may be the most frequent functional MC4R mutation leading to the severe obesity in general population and provides new insight into the functionality of population based variants of the MC4R.
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Affiliation(s)
- Vita Rovite
- Latvian Biomedical Research and Study Centre, Ratsupites Str. 1, 1067, Riga, Latvia
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50
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Karamitri A, Jockers R. Exon Sequencing of G Protein-Coupled Receptor Genes and Perspectives for Disease Treatment. METHODS IN PHARMACOLOGY AND TOXICOLOGY 2014. [DOI: 10.1007/978-1-62703-779-2_17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
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