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Implication of Melanocortin Receptor Genes in the Familial Comorbidity of Type 2 Diabetes and Depression. Int J Mol Sci 2022; 23:ijms23158350. [PMID: 35955479 PMCID: PMC9369258 DOI: 10.3390/ijms23158350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 12/20/2022] Open
Abstract
The melanocortin receptors are G-protein-coupled receptors, which are essential components of the hypothalamic–pituitary–adrenal axis, and they mediate the actions of melanocortins (melanocyte-stimulating hormones: α-MSH, β-MSH, and γ-MSH) as well as the adrenocorticotropin hormone (ACTH) in skin pigmentation, adrenal steroidogenesis, and stress response. Three melanocortin receptor genes (MC1R, MC2R, and MC5R) contribute to the risk of major depressive disorder (MDD), and one melanocortin receptor gene (MC4R) contributes to the risk of type 2 diabetes (T2D). MDD increases T2D risk in drug-naïve patients; thus, MDD and T2D commonly coexist. The five melanocortin receptor genes might confer risk for both disorders. However, they have never been investigated jointly to evaluate their potential contributing roles in the MDD-T2D comorbidity, specifically within families. In 212 Italian families with T2D and MDD, we tested 11 single nucleotide polymorphisms (SNPs) in the MC1R gene, 9 SNPs in MC2R, 3 SNPs in MC3R, 4 SNPs in MC4R, and 2 SNPs in MC5R. The testing used 2-point parametric linkage and linkage disequilibrium (LD) (i.e., association) analysis with four models (dominant with complete penetrance (D1), dominant with incomplete penetrance (D2), recessive with complete penetrance (R1), and recessive with incomplete penetrance (R2)). We detected significant (p ≤ 0.05) linkage and/or LD (i.e., association) to/with MDD for one SNP in MC2R (rs111734014) and one SNP in MC5R (rs2236700), and to/with T2D for three SNPs in MC1R (rs1805007 and rs201192930, and rs2228479), one SNP in MC2R (rs104894660), two SNPs in MC3R (rs3746619 and rs3827103), and one SNP in MC4R genes (Chr18-60372302). The linkage/LD/association was significant across different linkage patterns and different modes of inheritance. All reported variants are novel in MDD and T2D. This is the first study to report risk variants in MC1R, MC2R, and MC3R genes in T2D. MC2R and MC5R genes are replicated in MDD, with one novel variant each. Within our dataset, only the MC2R gene appears to confer risk for both MDD and T2D, albeit with different risk variants. To further clarity the role of the melanocortin receptor genes in MDD-T2D, these findings should be sought among other ethnicities as well.
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Demidowich AP, Parikh VJ, Dedhia N, Branham RE, Madi SA, Marwitz SE, Roberson RB, Uhlman AJ, Levi NJ, Mi SJ, Jun JY, Broadney MM, Brady SM, Yanovski JA. Associations of the melanocortin 3 receptor C17A + G241A haplotype with body composition and inflammation in African-American adults. Ann Hum Genet 2019; 83:355-360. [PMID: 30937899 DOI: 10.1111/ahg.12315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 03/11/2019] [Accepted: 03/17/2019] [Indexed: 01/02/2023]
Abstract
BACKGROUND The MC3R haplotype C17A + G241A, which encodes a partially inactivated receptor, has high prevalence in individuals of predominately African ancestry. In pediatric cohorts, homozygosity for this common variant has been associated with obesity, reduced lean mass, and greater fasting insulin. However, metabolic and body composition measures have not been well studied in adults with this haplotype. METHODS A convenience sample of 237 healthy African-American adult volunteers was studied. TaqMan assays were used to genotype MC3R variants. Labs were drawn in the morning in the fasted state. Body composition data was obtained via dual-energy X-ray absorptiometry. An analysis of covariance was used to examine the associations of genotype with metabolic and body composition measures controlling for age and sex. RESULTS Individuals homozygous for the MC3R C17A + G241A haplotype had significantly greater body mass index, fat mass, fat mass percentage, and C-reactive protein, with reduced lean mass percentage as compared to heterozygous and wild-type participants (all ps < 0.05); fasting insulin was marginally nonsignificant between groups (p = 0.053). After adjusting for fat mass, laboratory differences no longer remained significant. CONCLUSIONS Homozygosity for MC3R C17A + G241A is associated with increased adiposity in African-American adults. Further studies are needed to elucidate the mechanisms behind these associations.
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Affiliation(s)
- Andrew P Demidowich
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892.,Office of the Clinical Director, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Viraj J Parikh
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Nicket Dedhia
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Rachel E Branham
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Samar A Madi
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Shannon E Marwitz
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Robin B Roberson
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Andrew J Uhlman
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Noah J Levi
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Sarah J Mi
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Joo Yun Jun
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Miranda M Broadney
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Sheila M Brady
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
| | - Jack A Yanovski
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, DHHS, Bethesda, MD, 20892
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Demidowich AP, Jun JY, Yanovski JA. Polymorphisms and mutations in the melanocortin-3 receptor and their relation to human obesity. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2468-2476. [PMID: 28363697 DOI: 10.1016/j.bbadis.2017.03.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 12/18/2022]
Abstract
Inactivating mutations in the melanocortin 3 receptor (Mc3r) have been described as causing obesity in mice, but the physiologic effects of MC3R mutations in humans have been less clear. Here we review the MC3R polymorphisms and mutations identified in humans, and the in vitro, murine, and human cohort studies examining their putative effects. Some, but not all, studies suggest that the common human MC3R variant T6K+V81I, as well as several other rare, function-altering mutations, are associated with greater adiposity and hyperleptinemia with altered energy partitioning. In vitro, the T6K+V81I variant appears to decrease MC3R expression and therefore cAMP generation in response to ligand binding. Knockin mouse studies confirm that the T6K+V81I variant increases feeding efficiency and the avidity with which adipocytes derived from bone or adipose tissue stem cells store triglycerides. Other MC3R mutations occur too infrequently in the human population to make definitive conclusions regarding their clinical effects. This article is part of a Special Issue entitled: Melanocortin Receptors - edited by Ya-Xiong Tao.
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Affiliation(s)
- Andrew P Demidowich
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Joo Yun Jun
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Jack A Yanovski
- Section on Growth and Obesity, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States.
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Aris IM, Tint MT, Teh AL, Holbrook JD, Quah PL, Chong MF, Lin X, Soh SE, Saw S, Kwek K, Godfrey KM, Gluckman PD, Chong YS, Lek N, Yap F, Lee YS. MC3R gene polymorphisms are associated with early childhood adiposity gain and infant appetite in an Asian population. Pediatr Obes 2016; 11:450-458. [PMID: 26663875 PMCID: PMC5111755 DOI: 10.1111/ijpo.12086] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/17/2015] [Accepted: 10/24/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND Polymorphic variants within human melanocortin-3 receptor gene (MC3R) gene have been associated with obesity. However, its influence on infancy and early childhood adiposity has not been reported before. OBJECTIVES We assessed associations between genotype at polymorphic sites within MC3R with early childhood adiposity and interaction with early childhood appetitive traits. METHODS We studied 1090 singletons in an Asian mother-offspring cohort genotyped for MC3R and in a subgroup (n = 422) who had completed Child Eating Behaviour Questionnaires (CEBQ) at 12 months. Children were followed from birth to 48 months, and up to 10 measurements of body mass index and five measures of triceps and subscapular skin-folds were obtained. RESULTS Independent of potential confounders, each additional MC3R minor allele copy was associated with greater body mass index standard deviation score [B{95% confidence interval}: 0.004 units/month {0.001,0.007}; p = 0.007], triceps [0.009 mm/month {0.001,0.02}; p = 0.021] and subscapular skin-fold [0.008 mm/month {0.002,0.01}; p = 0.011] gain velocity in the first 48 months. Each additional MC3R minor allele copy was also associated with increased odds of overweight [odds ratio {95% confidence interval}: 1.48{1.17-1.88}] and obesity [1.58{1.10-2.28}] in the first 48 months. Every additional copy of MC3R minor allele was positively associated with 'slowness-in-eating' appetitive trait [0.24{0.06,0.39}, p = 0.006]; however, the relationship between 'slowness-in-eating' with adiposity gain was not statistically significant. CONCLUSIONS Our findings support the role of MC3R genetic variants in adiposity gain during early childhood.
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Affiliation(s)
- I. M. Aris
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - M. T. Tint
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - A. L. Teh
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
| | - J. D. Holbrook
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
| | - P. L. Quah
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
| | - M. F.‐F. Chong
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - X. Lin
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
| | - S. E. Soh
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - S.‐M. Saw
- Saw Swee Hock School of Public HealthNational University of SingaporeSingapore
| | - K. Kwek
- Department of Maternal Fetal MedicineKK Women's and Children's HospitalSingapore
| | - K. M. Godfrey
- MRC Lifecourse Epidemiology Unit and NIHR Southampton Biomedical Research CentreUniversity of Southampton and University Hospital Southampton NHS Foundation TrustSouthamptonUK
| | - P. D. Gluckman
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
- Liggins InstituteUniversity of AucklandAucklandNew Zealand
| | - Y. S. Chong
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - N. Lek
- Department of PaediatricsKK Women's and Children's HospitalSingapore
| | - F. Yap
- Department of PaediatricsKK Women's and Children's HospitalSingapore
| | - Y. S. Lee
- Singapore Institute for Clinical SciencesAgency for Science, Technology and ResearchSingapore
- Department of Paediatrics, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
- Khoo Teck Puat‐National University Children's Medical InstituteNational University Health SystemSingapore
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Park J, Sharma N, Cutting GR. Melanocortin 3 receptor has a 5' exon that directs translation of apically localized protein from the second in-frame ATG. Mol Endocrinol 2014; 28:1547-57. [PMID: 25051171 DOI: 10.1210/me.2014-1105] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Melanocortin-3 receptor (MC3R) is a canonical MSH receptor that plays an essential role in energy homeostasis. Variants in MC3R have been implicated in obesity in humans and mice. However, interpretation of the functional consequences of these variants is challenging because the translational start site of MC3R is unclear. Using 5' rapid amplification of cDNA ends, we discovered a novel upstream exon that extends the length of the 5' untranslated region (UTR) in MC3R without changing the open-reading frame. The full-length 5' UTR directs utilization of an evolutionarily conserved second in-frame ATG as the primary translation start site. MC3R synthesized from the second ATG is localized to apical membranes of polarized Madin-Darby canine kidney cells, consistent with its function as a cell surface mediator of melanocortin signaling. Expression of MC3R causes relocalization of melanocortin receptor accessory protein 2, an accessory factor for melanocortin-2 receptor, to the apical membrane, coincident with the location of MC3R. In contrast, protein synthesized from MC3R cDNAs lacking the 5' UTR displayed diffuse cytosolic distribution and has no effect on the distribution of melanocortin receptor accessory protein 2. Our findings demonstrate that a previously unannotated 5' exon directs translation of MC3R protein that localizes to apical membranes of polarized cells. Together, our work provides insight on the structure of human MC3R and reveals a new pathway for regulation of energy metabolism.
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Affiliation(s)
- Jeenah Park
- McKusick-Nathans Institute of Genetic Medicine (J.P., N.S., G.R.C.), Johns Hopkins University, Baltimore, Maryland 21218; and Department of Pediatrics (G.R.C.), Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-3914
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Common polymorphism (81Val>Ile) and rare mutations (257Arg>Ser and 335Ile>Ser) of the MC3R gene in obese Polish children and adolescents. Mol Biol Rep 2013; 40:6893-8. [PMID: 24142065 PMCID: PMC3835951 DOI: 10.1007/s11033-013-2808-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 10/12/2013] [Indexed: 01/11/2023]
Abstract
The predisposing role to human obesity of the MC3R gene polymorphism is controversial. In this report we present the first study focused on the search for the MC3R polymorphism in the Polish population. Altogether 257 obese children and adolescents (RBMI>120) and 94 adults, who were never obese or overweight (BMI<25), were studied. For all subjects the entire coding sequence was analyzed by direct DNA sequencing. One common polymorphism (81Val>Ile) and two rare mutations (257Arg>Ser and 335Ile>Ser) were identified. The common polymorphism was widely distributed in the obese and control cohorts, while the mutations were identified in four obese subjects only. In case of the 335Ile>Ser substitution a three-generation family, consisting of 20 members, was also analyzed. It was found that all carriers of the 335Ser mutation were obese, but among non-carriers obese subjects also were found. Our study suggests that the predisposing effect to obesity of the 81Ile polymorphic variant is rather unlikely. With regard to the studied rare mutations we suggest that the 335Ser allele may have a small predisposing effect.
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Obregón AM, Diaz E, Santos JL. Effect of the melanocortin-3 receptor Thr6Lys and Val81Ile genetic variants on body composition and substrate oxidation in Chilean obese children. J Physiol Biochem 2011; 68:71-6. [PMID: 21983807 DOI: 10.1007/s13105-011-0120-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 08/31/2011] [Indexed: 01/24/2023]
Abstract
Mice genetically deficient in the melanocortin-3 receptor gene are characterized by normal body weight, increased body fat, mild hypophagia, reduced locomotor activity, and increased respiratory quotient compared with wild-type mice. In humans, the 6Lys-81Ile haplotype of melanocortin-3 receptor (MC3R) gene has been associated with childhood obesity, higher body fat percentage, and reduced fat oxidation compared to non-carriers. The aim of this study was to evaluate the association between MC3R 6Lys-81Ile haplotype with body composition and substrate oxidation in response to moderate exercise in obese children. Eight Chilean obese children (aged 8-12) carriers of MC3R 6Lys-81Ile haplotype were compared with eight age-gender-matched obese non-carriers. Children were identified through a previous cross-sectional study on genetic determinants of childhood obesity (n = 229). Genotypes for MC3R Thr6Lys and Val81Ile were determined by polymerase chain reaction-restriction fragment length polymorphism. Body composition was assessed by the four-compartment model (dual-energy X-ray absorptiometry, total body water by the deuterium dilution technique, and total fat mass by air-displacement plethysmography). Substrate oxidation was assessed by indirect calorimetry in response to moderate exercise (60% VO(2 max)). Wilcoxon matched-pairs test was used to compare quantitative variables. No significant differences among carriers and non-carriers were found in anthropometrical and body composition measurements. The Carriers of the 6Lys-81Ile haplotype showed higher respiratory quotient (p = 0.06) and a significantly higher glucose oxidation (p = 0.01) compared with non-carriers after standardization for fat-free mass. Our results are consistent with a possible participation of MC3R 6Lys-81Ile variants in glucose oxidation in response to moderate exercise.
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Affiliation(s)
- Ana M Obregón
- Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O'Higgins 340, Santiago 8331150, Chile.
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