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Lam BYH, Williamson A, Finer S, Day FR, Tadross JA, Gonçalves Soares A, Wade K, Sweeney P, Bedenbaugh MN, Porter DT, Melvin A, Ellacott KLJ, Lippert RN, Buller S, Rosmaninho-Salgado J, Dowsett GKC, Ridley KE, Xu Z, Cimino I, Rimmington D, Rainbow K, Duckett K, Holmqvist S, Khan A, Dai X, Bochukova EG, Trembath RC, Martin HC, Coll AP, Rowitch DH, Wareham NJ, van Heel DA, Timpson N, Simerly RB, Ong KK, Cone RD, Langenberg C, Perry JRB, Yeo GS, O'Rahilly S. MC3R links nutritional state to childhood growth and the timing of puberty. Nature 2021; 599:436-441. [PMID: 34732894 PMCID: PMC8819628 DOI: 10.1038/s41586-021-04088-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 10/01/2021] [Indexed: 02/02/2023]
Abstract
The state of somatic energy stores in metazoans is communicated to the brain, which regulates key aspects of behaviour, growth, nutrient partitioning and development1. The central melanocortin system acts through melanocortin 4 receptor (MC4R) to control appetite, food intake and energy expenditure2. Here we present evidence that MC3R regulates the timing of sexual maturation, the rate of linear growth and the accrual of lean mass, which are all energy-sensitive processes. We found that humans who carry loss-of-function mutations in MC3R, including a rare homozygote individual, have a later onset of puberty. Consistent with previous findings in mice, they also had reduced linear growth, lean mass and circulating levels of IGF1. Mice lacking Mc3r had delayed sexual maturation and an insensitivity of reproductive cycle length to nutritional perturbation. The expression of Mc3r is enriched in hypothalamic neurons that control reproduction and growth, and expression increases during postnatal development in a manner that is consistent with a role in the regulation of sexual maturation. These findings suggest a bifurcating model of nutrient sensing by the central melanocortin pathway with signalling through MC4R controlling the acquisition and retention of calories, whereas signalling through MC3R primarily regulates the disposition of calories into growth, lean mass and the timing of sexual maturation.
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Affiliation(s)
- B Y H Lam
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - A Williamson
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - S Finer
- Wolfson Institute of Population Health, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - F R Day
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - J A Tadross
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - A Gonçalves Soares
- MRC Integrative Epidemiology Unit and Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - K Wade
- MRC Integrative Epidemiology Unit and Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - P Sweeney
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - M N Bedenbaugh
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - D T Porter
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - A Melvin
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - K L J Ellacott
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - R N Lippert
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition, Potsdam, Germany
| | - S Buller
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - J Rosmaninho-Salgado
- Medical Genetics Unit, Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - G K C Dowsett
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - K E Ridley
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - Z Xu
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - I Cimino
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - D Rimmington
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - K Rainbow
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - K Duckett
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - S Holmqvist
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - A Khan
- Wolfson Institute of Population Health, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - X Dai
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University London, London, UK
| | - E G Bochukova
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University London, London, UK
| | - R C Trembath
- School of Basic and Medical Biosciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - H C Martin
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - A P Coll
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - D H Rowitch
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - N J Wareham
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - D A van Heel
- Wolfson Institute of Population Health, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University London, London, UK
| | - N Timpson
- MRC Integrative Epidemiology Unit and Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - R B Simerly
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - K K Ong
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - R D Cone
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - C Langenberg
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- Computational Medicine, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - J R B Perry
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - G S Yeo
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK
| | - S O'Rahilly
- MRC Metabolic Diseases Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK.
- NIHR Cambridge Biomedical Research Centre, Cambridge, UK.
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2
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Anderson EJP, Ghamari-Langroudi M, Cakir I, Litt MJ, Chen V, Reggiardo RE, Millhauser GL, Cone RD. Late onset obesity in mice with targeted deletion of potassium inward rectifier Kir7.1 from cells expressing the melanocortin-4 receptor. J Neuroendocrinol 2019; 31:e12670. [PMID: 30561082 PMCID: PMC6533113 DOI: 10.1111/jne.12670] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 11/21/2018] [Accepted: 12/11/2018] [Indexed: 01/01/2023]
Abstract
Energy stores in fat tissue are determined in part by the activity of hypothalamic neurones expressing the melanocortin-4 receptor (MC4R). Even a partial reduction in MC4R expression levels in mice, rats or humans produces hyperphagia and morbid obesity. Thus, it is of great interest to understand the molecular basis of neuromodulation by the MC4R. The MC4R is a G protein-coupled receptor that signals efficiently through GαS , and this signalling pathway is essential for normal MC4R function in vivo. However, previous data from hypothalamic slice preparations indicated that activation of the MC4R depolarised neurones via G protein-independent regulation of the ion channel Kir7.1. In the present study, we show that deletion of Kcnj13 (ie, the gene encoding Kir7.1) specifically from MC4R neurones produced resistance to melanocortin peptide-induced depolarisation of MC4R paraventricular nucleus neurones in brain slices, resistance to the sustained anorexic effect of exogenously administered melanocortin peptides, late onset obesity, increased linear growth and glucose intolerance. Some MC4R-mediated phenotypes appeared intact, including Agouti-related peptide-induced stimulation of food intake and MC4R-mediated induction of peptide YY release from intestinal L cells. Thus, a subset of the consequences of MC4R signalling in vivo appears to be dependent on expression of the Kir7.1 channel in MC4R cells.
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Affiliation(s)
- E. J. P. Anderson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
| | - M. Ghamari-Langroudi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
| | - I. Cakir
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
| | - M. J. Litt
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
| | - Valerie Chen
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California
| | - Roman E. Reggiardo
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California
| | - Glenn L. Millhauser
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California
| | - R. D. Cone
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
- Department of Molecular and Integrative Pharmacology, School of Medicine, University of Michigan, Ann Arbor, Michigan
- Correspondence: Roger D. Cone, Life Sciences Institute, 210 Washtenaw Ave., Ann Arbor, MI 48109,
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3
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Boraska V, Franklin CS, Floyd JAB, Thornton LM, Huckins LM, Southam L, Rayner NW, Tachmazidou I, Klump KL, Treasure J, Lewis CM, Schmidt U, Tozzi F, Kiezebrink K, Hebebrand J, Gorwood P, Adan RAH, Kas MJH, Favaro A, Santonastaso P, Fernández-Aranda F, Gratacos M, Rybakowski F, Dmitrzak-Weglarz M, Kaprio J, Keski-Rahkonen A, Raevuori A, Van Furth EF, Slof-Op 't Landt MCT, Hudson JI, Reichborn-Kjennerud T, Knudsen GPS, Monteleone P, Kaplan AS, Karwautz A, Hakonarson H, Berrettini WH, Guo Y, Li D, Schork NJ, Komaki G, Ando T, Inoko H, Esko T, Fischer K, Männik K, Metspalu A, Baker JH, Cone RD, Dackor J, DeSocio JE, Hilliard CE, O'Toole JK, Pantel J, Szatkiewicz JP, Taico C, Zerwas S, Trace SE, Davis OSP, Helder S, Bühren K, Burghardt R, de Zwaan M, Egberts K, Ehrlich S, Herpertz-Dahlmann B, Herzog W, Imgart H, Scherag A, Scherag S, Zipfel S, Boni C, Ramoz N, Versini A, Brandys MK, Danner UN, de Kovel C, Hendriks J, Koeleman BPC, Ophoff RA, Strengman E, van Elburg AA, Bruson A, Clementi M, Degortes D, Forzan M, Tenconi E, Docampo E, Escaramís G, Jiménez-Murcia S, Lissowska J, Rajewski A, Szeszenia-Dabrowska N, Slopien A, Hauser J, Karhunen L, Meulenbelt I, Slagboom PE, Tortorella A, Maj M, Dedoussis G, Dikeos D, Gonidakis F, Tziouvas K, Tsitsika A, Papezova H, Slachtova L, Martaskova D, Kennedy JL, Levitan RD, Yilmaz Z, Huemer J, Koubek D, Merl E, Wagner G, Lichtenstein P, Breen G, Cohen-Woods S, Farmer A, McGuffin P, Cichon S, Giegling I, Herms S, Rujescu D, Schreiber S, Wichmann HE, Dina C, Sladek R, Gambaro G, Soranzo N, Julia A, Marsal S, Rabionet R, Gaborieau V, Dick DM, Palotie A, Ripatti S, Widén E, Andreassen OA, Espeseth T, Lundervold A, Reinvang I, Steen VM, Le Hellard S, Mattingsdal M, Ntalla I, Bencko V, Foretova L, Janout V, Navratilova M, Gallinger S, Pinto D, Scherer SW, Aschauer H, Carlberg L, Schosser A, Alfredsson L, Ding B, Klareskog L, Padyukov L, Courtet P, Guillaume S, Jaussent I, Finan C, Kalsi G, Roberts M, Logan DW, Peltonen L, Ritchie GRS, Barrett JC, Estivill X, Hinney A, Sullivan PF, Collier DA, Zeggini E, Bulik CM. A genome-wide association study of anorexia nervosa. Mol Psychiatry 2014; 19:1085-94. [PMID: 24514567 PMCID: PMC4325090 DOI: 10.1038/mp.2013.187] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 11/21/2013] [Accepted: 11/25/2013] [Indexed: 02/06/2023]
Abstract
Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome-wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2907 cases with AN from 14 countries (15 sites) and 14 860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3). Individual association analyses were conducted in each stratum and meta-analyzed across all 15 discovery data sets. Seventy-six (72 independent) single nucleotide polymorphisms were taken forward for in silico (two data sets) or de novo (13 data sets) replication genotyping in 2677 independent AN cases and 8629 European ancestry controls along with 458 AN cases and 421 controls from Japan. The final global meta-analysis across discovery and replication data sets comprised 5551 AN cases and 21 080 controls. AN subtype analyses (1606 AN restricting; 1445 AN binge-purge) were performed. No findings reached genome-wide significance. Two intronic variants were suggestively associated: rs9839776 (P=3.01 × 10(-7)) in SOX2OT and rs17030795 (P=5.84 × 10(-6)) in PPP3CA. Two additional signals were specific to Europeans: rs1523921 (P=5.76 × 10(-)(6)) between CUL3 and FAM124B and rs1886797 (P=8.05 × 10(-)(6)) near SPATA13. Comparing discovery with replication results, 76% of the effects were in the same direction, an observation highly unlikely to be due to chance (P=4 × 10(-6)), strongly suggesting that true findings exist but our sample, the largest yet reported, was underpowered for their detection. The accrual of large genotyped AN case-control samples should be an immediate priority for the field.
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Affiliation(s)
- V Boraska
- 1] Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK [2] University of Split School of Medicine, Split, Croatia
| | - C S Franklin
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - J A B Floyd
- 1] Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK [2] William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London, UK
| | - L M Thornton
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - L M Huckins
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - L Southam
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - N W Rayner
- 1] Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK [2] Wellcome Trust Centre for Human Genetics (WTCHG), University of Oxford, Oxford, UK [3] Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Oxford, UK
| | - I Tachmazidou
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - K L Klump
- Department of Psychology, Michigan State University, East Lansing, MI, USA
| | - J Treasure
- Section of Eating Disorders, Institute of Psychiatry, King's College London, London, UK
| | - C M Lewis
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
| | - U Schmidt
- Section of Eating Disorders, Institute of Psychiatry, King's College London, London, UK
| | - F Tozzi
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - K Kiezebrink
- Health Services Research Unit, University of Aberdeen, Aberdeen, UK
| | - J Hebebrand
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, University of Duisburg-Essen, Essen, Germany
| | - P Gorwood
- 1] INSERM U894, Centre of Psychiatry and Neuroscience, Paris, France [2] Sainte-Anne Hospital (CMME), University of Paris-Descartes, Paris, France
| | - R A H Adan
- 1] Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands [2] Altrecht Eating Disorders Rintveld, Zeist, The Netherlands
| | - M J H Kas
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - A Favaro
- Department of Neurosciences, University of Padova, Padova, Italy
| | - P Santonastaso
- Department of Neurosciences, University of Padova, Padova, Italy
| | - F Fernández-Aranda
- 1] Department of Psychiatry and CIBERON, University Hospital of Bellvitge-IDIBELL, Barcelona, Spain [2] Department of Clinical Sciences, School of Medicine, University of Barcelona, Barcelona, Spain
| | - M Gratacos
- 1] Genomics and Disease Group, Centre for Genomic Regulation (CRG), Barcelona, Spain [2] Universitat Pompeu Fabra (UPF), Barcelona, Spain [3] Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain [4] Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - F Rybakowski
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - M Dmitrzak-Weglarz
- Department of Psychiatry, Poznan University of Medical Sciences, Poznan, Poland
| | - J Kaprio
- 1] Hjelt Institute, University of Helsinki, Helsinki, Finland [2] Institute of Molecular Medicine, University of Helsinki, Helsinki, Finland [3] Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland
| | | | - A Raevuori
- 1] Hjelt Institute, University of Helsinki, Helsinki, Finland [2] Department of Adolescent Psychiatry, Helsinki University Central Hospital, Helsinki, Finland
| | - E F Van Furth
- 1] Center for Eating Disorders Ursula, Leidschendam, The Netherlands [2] Department of Psychiatry, Leiden University Medical Centre, Leiden, The Netherlands
| | - M C T Slof-Op 't Landt
- 1] Center for Eating Disorders Ursula, Leidschendam, The Netherlands [2] Molecular Epidemiology Section, Department of Medical Statistics, Leiden University Medical Centre, Leiden, The Netherlands
| | - J I Hudson
- Department of Psychiatry, McLean Hospital/Harvard Medical School, Belmont, MA, USA
| | - T Reichborn-Kjennerud
- 1] Department of Genetics, Environment and Mental Health, Norwegian Institute of Public Health, Oslo, Norway [2] Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - G P S Knudsen
- Department of Genetics, Environment and Mental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - P Monteleone
- 1] Department of Psychiatry, University of Naples SUN, Naples, Italy [2] Chair of Psychiatry, University of Salerno, Salerno, Italy
| | - A S Kaplan
- 1] Centre for Addiction and Mental Health, Toronto, ON, Canada [2] Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - A Karwautz
- Eating Disorders Unit, Department of Child and Adolescent Psychiatry, Medical University of Vienna, Vienna, Austria
| | - H Hakonarson
- 1] The Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA [2] The Division of Human Genetics, Department of Pediatrics, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - W H Berrettini
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA
| | - Y Guo
- The Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - D Li
- The Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - N J Schork
- Department of Molecular and Experimental Medicine and The Scripps Translational Science Institute, The Scripps Research Institute, La Jolla, CA, USA
| | - G Komaki
- 1] Department of Psychosomatic Research, National Institute of Mental Health, NCNP, Tokyo, Japan [2] School of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan
| | - T Ando
- Department of Psychosomatic Research, National Institute of Mental Health, NCNP, Tokyo, Japan
| | - H Inoko
- Department of Molecular Life Sciences, Tokai University School of Medicine, Kanagawa, Japan
| | - T Esko
- Estonian Genome Center, University of Tartu, Tartu, Estonia
| | - K Fischer
- Estonian Genome Center, University of Tartu, Tartu, Estonia
| | - K Männik
- 1] Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia [2] Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - A Metspalu
- 1] Estonian Genome Center, University of Tartu, Tartu, Estonia [2] Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - J H Baker
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - R D Cone
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - J Dackor
- Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - J E DeSocio
- Seattle University College of Nursing, Seattle, WA, USA
| | - C E Hilliard
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - J Pantel
- Centre de Psychiatrie et Neurosciences - Inserm U894, Paris, France
| | - J P Szatkiewicz
- Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - C Taico
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - S Zerwas
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - S E Trace
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - O S P Davis
- 1] Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK [2] Department of Genetics, Evolution and Environment, University College London, UCL Genetics Institute, London, UK
| | - S Helder
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
| | - K Bühren
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Clinics RWTH Aachen, Aachen, Germany
| | - R Burghardt
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Charité, Berlin, Germany
| | - M de Zwaan
- 1] Department of Psychosomatic Medicine and Psychotherapy, Hannover Medical School, Hannover, Germany [2] Department of Psychosomatic Medicine and Psychotherapy, University of Erlangen-Nuremberg, Erlangen, Germany
| | - K Egberts
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Würzburg, Würzburg, Germany
| | - S Ehrlich
- 1] Department of Child and Adolescent Psychiatry, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany [2] Athinoula A. Martinos Center for Biomedical Imaging, Psychiatric Neuroimaging Research Program, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, USA
| | - B Herpertz-Dahlmann
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Clinics RWTH Aachen, Aachen, Germany
| | - W Herzog
- Departments of Psychosocial and Internal Medicine, Heidelberg University, Heidelberg, Germany
| | - H Imgart
- Parklandklinik, Bad Wildungen, Germany
| | - A Scherag
- Institute for Medical Informatics, Biometry and Epidemiology, Universitätsklinikum Essen, University of Duisburg-Essen, Essen, Germany
| | - S Scherag
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, University of Duisburg-Essen, Essen, Germany
| | - S Zipfel
- Department of Internal Medicine VI, Psychosomatic Medicine and Psychotherapy, University Medical Hospital Tübingen, Tübingen, Germany
| | - C Boni
- INSERM U894, Centre of Psychiatry and Neuroscience, Paris, France
| | - N Ramoz
- INSERM U894, Centre of Psychiatry and Neuroscience, Paris, France
| | - A Versini
- INSERM U894, Centre of Psychiatry and Neuroscience, Paris, France
| | - M K Brandys
- 1] Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands [2] Altrecht Eating Disorders Rintveld, Zeist, The Netherlands
| | - U N Danner
- Altrecht Eating Disorders Rintveld, Zeist, The Netherlands
| | - C de Kovel
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - J Hendriks
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - B P C Koeleman
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - R A Ophoff
- 1] Center for Neurobehavioral Genetics, University of California, Los Angeles, Los Angeles, CA, USA [2] Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - E Strengman
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - A A van Elburg
- 1] Altrecht Eating Disorders Rintveld, Zeist, The Netherlands [2] Department of Child and Adolescent Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands
| | - A Bruson
- Clinical Genetics Unit, Department of Woman and Child Health, University of Padova, Padova, Italy
| | - M Clementi
- Clinical Genetics Unit, Department of Woman and Child Health, University of Padova, Padova, Italy
| | - D Degortes
- Department of Neurosciences, University of Padova, Padova, Italy
| | - M Forzan
- Clinical Genetics Unit, Department of Woman and Child Health, University of Padova, Padova, Italy
| | - E Tenconi
- Department of Neurosciences, University of Padova, Padova, Italy
| | - E Docampo
- 1] Genomics and Disease Group, Centre for Genomic Regulation (CRG), Barcelona, Spain [2] Universitat Pompeu Fabra (UPF), Barcelona, Spain [3] Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain [4] Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - G Escaramís
- 1] Genomics and Disease Group, Centre for Genomic Regulation (CRG), Barcelona, Spain [2] Universitat Pompeu Fabra (UPF), Barcelona, Spain [3] Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain [4] Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - S Jiménez-Murcia
- 1] Department of Psychiatry and CIBERON, University Hospital of Bellvitge-IDIBELL, Barcelona, Spain [2] Department of Clinical Sciences, School of Medicine, University of Barcelona, Barcelona, Spain
| | - J Lissowska
- M. Sklodowska-Curie Cancer Center and Institute of Oncology, Warsaw, Poland
| | - A Rajewski
- Department of Epidemiology, Institute of Occupational Medicine, Department of Epidemiology, Lodz, Poland
| | - N Szeszenia-Dabrowska
- Department of Epidemiology, Institute of Occupational Medicine, Department of Epidemiology, Lodz, Poland
| | - A Slopien
- Department of Psychiatry, Poznan University of Medical Sciences, Poznan, Poland
| | - J Hauser
- Department of Psychiatry, Poznan University of Medical Sciences, Poznan, Poland
| | - L Karhunen
- Department of Clinical Nutrition, Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
| | - I Meulenbelt
- Molecular Epidemiology Section, Department of Medical Statistics, Leiden University Medical Centre, Leiden, The Netherlands
| | - P E Slagboom
- 1] Molecular Epidemiology Section, Department of Medical Statistics, Leiden University Medical Centre, Leiden, The Netherlands [2] Netherlands Consortium for Healthy Ageing, Leiden University Medical Center, Leiden, The Netherlands
| | - A Tortorella
- Department of Psychiatry, University of Naples SUN, Naples, Italy
| | - M Maj
- Department of Psychiatry, University of Naples SUN, Naples, Italy
| | - G Dedoussis
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | - D Dikeos
- 1st Department of Psychiatry, Athens University Medical School, Athens, Greece
| | - F Gonidakis
- Eating Disorders Unit, 1st Department of Psychiatry, Athens University Medical School, Athens, Greece
| | - K Tziouvas
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | - A Tsitsika
- Adolescent Health Unit (A.H.U.), 2nd Department of Pediatrics - Medical School, University of Athens 'P. & A. Kyriakou' Children's Hospital, Athens, Greece
| | - H Papezova
- Department of Psychiatry, 1st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - L Slachtova
- Department of Pediatrics, 1st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - D Martaskova
- Department of Psychiatry, 1st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - J L Kennedy
- 1] Centre for Addiction and Mental Health, Toronto, ON, Canada [2] Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - R D Levitan
- 1] Centre for Addiction and Mental Health, Toronto, ON, Canada [2] Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Z Yilmaz
- 1] Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA [2] Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - J Huemer
- Eating Disorders Unit, Department of Child and Adolescent Psychiatry, Medical University of Vienna, Vienna, Austria
| | - D Koubek
- Eating Disorders Unit, Department of Child and Adolescent Psychiatry, Medical University of Vienna, Vienna, Austria
| | - E Merl
- Eating Disorders Unit, Department of Child and Adolescent Psychiatry, Medical University of Vienna, Vienna, Austria
| | - G Wagner
- Eating Disorders Unit, Department of Child and Adolescent Psychiatry, Medical University of Vienna, Vienna, Austria
| | - P Lichtenstein
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - G Breen
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
| | - S Cohen-Woods
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
| | - A Farmer
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
| | - P McGuffin
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
| | - S Cichon
- 1] Department of Genomics, Life & Brain Center, Institute of Human Genetics, University of Bonn, Bonn, Germany [2] Institute of Neuroscience and Medicine (INM-1), Research Center Jülich, Jülich, Germany [3] Division of Medical Genetics, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - I Giegling
- Klinikum der Medizinischen Fakultät, Martin-Luther-Universität Halle-Wittenberg, Halle/Saale, Germany
| | - S Herms
- 1] Department of Genomics, Life & Brain Center, Institute of Human Genetics, University of Bonn, Bonn, Germany [2] Division of Medical Genetics, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - D Rujescu
- Klinikum der Medizinischen Fakultät, Martin-Luther-Universität Halle-Wittenberg, Halle/Saale, Germany
| | - S Schreiber
- Institute of Clinical Molecular Biology, University of Kiel, Kiel, Germany
| | - H-E Wichmann
- 1] Institute of Epidemiology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany [2] Institute of Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-University, Munich, Germany
| | - C Dina
- CNRS 8090-Institute of Biology, Pasteur Institute, Lille, France
| | - R Sladek
- McGill University and Genome Quebec Innovation Centre, Montreal, QC, Canada
| | - G Gambaro
- Division of Nephrology, Department of Internal Medicine and Medical Specialties, Columbus-Gemelly Hospitals, Catholic University, Rome, Italy
| | - N Soranzo
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - A Julia
- Unitat de Recerca de Reumatologia (URR), Institut de Recerca Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - S Marsal
- Unitat de Recerca de Reumatologia (URR), Institut de Recerca Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - R Rabionet
- 1] Genomics and Disease Group, Centre for Genomic Regulation (CRG), Barcelona, Spain [2] Universitat Pompeu Fabra (UPF), Barcelona, Spain [3] Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain [4] Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - V Gaborieau
- Genetic Epidemiology Group, International Agency for Research on Cancer (IARC), Lyon, France
| | - D M Dick
- Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA
| | - A Palotie
- 1] Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK [2] The Finnish Institute of Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland [3] The Program for Human and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - S Ripatti
- 1] The Finnish Institute of Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland [2] Finnish Institute of Occupational Health, Helsinki, Finland
| | - E Widén
- 1] The Finnish Institute of Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland [2] Finnish Institute of Occupational Health, Helsinki, Finland
| | - O A Andreassen
- NORMENT, K.G. Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital & Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - T Espeseth
- 1] NORMENT, K.G. Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital & Institute of Clinical Medicine, University of Oslo, Oslo, Norway [2] Department of Psychology, University of Oslo, Oslo, Norway
| | - A Lundervold
- 1] Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway [2] Kavli Research Centre for Aging and Dementia, Haraldsplass Deaconess Hospital, Bergen, Norway [3] K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway
| | - I Reinvang
- Department of Psychology, University of Oslo, Oslo, Norway
| | - V M Steen
- 1] Department of Clinical Science, K.G. Jebsen Centre for Psychosis Research, Norwegian Centre For Mental Disorders Research (NORMENT), University of Bergen, Bergen, Norway [2] Dr Einar Martens Research Group for Biological Psychiatry, Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - S Le Hellard
- 1] Department of Clinical Science, K.G. Jebsen Centre for Psychosis Research, Norwegian Centre For Mental Disorders Research (NORMENT), University of Bergen, Bergen, Norway [2] Dr Einar Martens Research Group for Biological Psychiatry, Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - M Mattingsdal
- NORMENT, K.G. Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital & Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - I Ntalla
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | - V Bencko
- Institute of Hygiene and Epidemiology, 1st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - L Foretova
- Department of Cancer Epidemiology and Genetics, Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - V Janout
- Palacky University, Olomouc, Czech Republic
| | - M Navratilova
- Department of Cancer Epidemiology and Genetics, Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - S Gallinger
- 1] University Health Network, Toronto General Hospital, Toronto, ON, Canada [2] Mount Sinai Hospital, Samuel Lunenfeld Research Institute, Toronto, ON, Canada
| | - D Pinto
- Departments of Psychiatry, and Genetics and Genomic Sciences, Seaver Autism Center, and the Mindich Child Health and Development Institute, Mount Sinai School of Medicine, New York, NY, USA
| | - S W Scherer
- The Centre for Applied Genomics and Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - H Aschauer
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - L Carlberg
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - A Schosser
- Department of Psychiatry and Psychotherapy, Medical University of Vienna, Vienna, Austria
| | - L Alfredsson
- The Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - B Ding
- The Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - L Klareskog
- Rheumatology Unit, Department of Medicine at the Karolinska University Hospital, Solna, Sweden
| | - L Padyukov
- Rheumatology Unit, Department of Medicine at the Karolinska University Hospital, Solna, Sweden
| | - P Courtet
- 1] Inserm, U1061, Université Montpellier 1, Montpellier, France [2] Department of Emergency Psychiatry, CHU Montpellier, Montpellier, France
| | - S Guillaume
- 1] Inserm, U1061, Université Montpellier 1, Montpellier, France [2] Department of Emergency Psychiatry, CHU Montpellier, Montpellier, France
| | - I Jaussent
- 1] Inserm, U1061, Université Montpellier 1, Montpellier, France [2] Department of Emergency Psychiatry, CHU Montpellier, Montpellier, France
| | - C Finan
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - G Kalsi
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
| | - M Roberts
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
| | - D W Logan
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - L Peltonen
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - G R S Ritchie
- 1] Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK [2] European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge
| | - J C Barrett
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - X Estivill
- 1] Genomics and Disease Group, Centre for Genomic Regulation (CRG), Barcelona, Spain [2] Universitat Pompeu Fabra (UPF), Barcelona, Spain [3] Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain [4] Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - A Hinney
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, University of Duisburg-Essen, Essen, Germany
| | - P F Sullivan
- 1] Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA [2] Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - D A Collier
- 1] Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK [2] Eli Lilly and Company, Erl Wood Manor, Windlesham, UK
| | - E Zeggini
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - C M Bulik
- 1] Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA [2] Department of Nutrition, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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4
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Abstract
Leptin is an adipocyte-derived hormone that acts as a major regulator of food intake and energy homeostasis. It circulates both as a free and as a protein-bound entity. Leptin is released into the blood in proportion to the amount of body fat and exerts sustained inhibitory effects on food intake while increasing energy expenditure. The leptin receptor belongs to the class I cytokine receptor superfamily and possesses strong homology to the signal-transducing subunits of the IL-6 receptor. The hypothalamic melanocortin system, and specifically the melanocortin-4 receptor (MC-4R), is critical in mediating leptin's effect on appetite and metabolism. Serum leptin concentrations are elevated in patients with chronic kidney disease (CKD) and correlate with C-reactive protein levels suggesting that inflammation is an important factor that contributes to hyperleptinemia in CKD. Hyperleptinemia may be important in the pathogenesis of inflammation-associated cachexia in CKD. We showed that experimental uremic cachexia was attenuated in db/db mice, a model of leptin receptor deficiency. Nephrectomy in these animals did not result in any change in weight gain, body composition, resting metabolic rate, and efficiency of food consumption. Furthermore, experimental uremic cachexia could be ameliorated by blocking leptin signaling through the hypothalamic MC-4R. MC-4R knockout mice or mice administered the MC-4R and MC-3R antagonist, agouti-related peptide, resisted uremia-induced loss of lean body mass and maintained normal basal metabolic rates. Thus, melanocortin receptor antagonism may provide a novel therapeutic strategy for inflammation-associated cachexia in CKD.
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Affiliation(s)
- R H Mak
- Department of Pediatrics, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
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5
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Batra A, Marks DL, Orwoll E, Cone RD, Kaye J, Newcomb K, Purnell JQ. 321 DESCRIPTION OF NOVEL POLYMORPHISMS IN THE CODING AND PROMOTER REGIONS OF THE MELANOCORTIN 4 RECEPTOR GENE IN AFRICAN AMERICANS. J Investig Med 2006. [DOI: 10.2310/6650.2005.x0004.320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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6
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Batterham RL, Cowley MA, Small CJ, Herzog H, Cohen MA, Dakin CL, Wren AM, Brynes AE, Low MJ, Ghatei MA, Cone RD, Bloom SR. Physiology: Does gut hormone PYY3–36 decrease food intake in rodents? Nature 2004. [DOI: 10.1038/nature02666a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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7
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Marks DL, Butler AA, Cone RD. Melanocortin pathway: animal models of obesity and disease. Ann Endocrinol (Paris) 2002; 63:121-4. [PMID: 11994674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Affiliation(s)
- D L Marks
- Department of Pediatric Endocrinology, Oregon Health Sciences University, Portland, OR 97201, USA
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8
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Abstract
Identifying the role of the melanocortin system in regulating energy homeostasis has relied on both genetic and pharmacological studies. The key findings included 1) that the coat color phenotype in the lethal yellow (A(Y)/a) mouse is due to antagonism of the melanocortin-1 receptor (MC1R) by the agouti gene product; 2) the MC3R and MC4R are expressed in CNS centers involved in energy homeostasis, and 3) the combined results of pharmacological studies showing that agouti is an antagonist of the MC4R and transgenic studies showing that inhibition or loss of the MC4R recapitulate the lethal yellow phenotype. Pro-opiomelanocortin (POMC), MC3R, and MC4R knockouts are obese and are now being used to further analyze melanocortin receptor function. The obesity phenotype observed in the MC3R and MC4R knockouts (KO) differ markedly. MC4RKO mice are hyperphagic, do not regulate pathways that increase energy expenditure (diet-induced thermogenesis) and physical activity in response to hyperphagia, and can develop type 2 diabetes. In contrast, MC3R deficient mice are not hyperphagic, have a normal metabolic response to increased energy consumption, and do not develop diabetes. The mechanism underlying the increased adiposity in the MC3R knockout remains unclear, but might be related to changes in nutrient partitioning or physical activity.
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Affiliation(s)
- A A Butler
- Neuropeptides Laboratory, Pennington Biomedical Research Center, Lousiana State university, Baton Rouge, LA70808, USA.
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9
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Abstract
Arcuate nucleus neurons are known to be responsive to a wide array of hormones and nutrients, including leptin, insulin, gonadal steroids and glucose. In addition to potential transport mechanisms, peripheral substances may access these neurons via arcuate cell bodies in and projections to the median eminence, a region considered to be a circumventricular organ. The arcuate is a potent site of leptin action, probably mediating a component of leptin's effects via arcuate neuropeptide Y/agouti-related peptide (NPY/AgRP) and pro-opiomelanocortin (POMC) neurons, and implicating this structure in the long-term control of energy stores. However, ghrelin, the endogenous ligand of the growth hormone secretagogue receptor, may also stimulate feeding and weight gain, in part through action on receptors in arcuate NPY neurons. Since ghrelin is secreted by the stomach upon content depletion, with a half-life of no more than an hour, the arcuate nucleus may also be important in sensing and responding to acute changes in nutrients. We have developed a system for recording from arcuate POMC neurons using a mouse containing a transgene in which the POMC promoter is driving expression of the green fluorescent protein (GFP). In these mice, 99% of the beta-endorphin positive neurons express GFP, making whole cell patch clamp recordings from the sparsely distributed POMC neurons facile. All of the POMC neurons appear to be activated by leptin, via two different mechanisms, while approximately 30-50% of the neurons appear to be inhibited by a gamma-melanocyte stimulating hormone (MSH) specific agonist. The latter result suggests that the melanocortin-3 receptor (MC3-R) may act as an autoinhibitory receptor on some POMC neurons. This hypothalamic slice preparation also confirms the responsiveness of arcuate POMC neurons to a wide variety of nutrients and hormones. Thus the arcuate melanocortin system is best described as a conduit of many diverse signals involved in energy homeostasis, with leptin acting tonically to regulate the responsiveness of the circuit to a wide variety of hormones and nutrients.
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Affiliation(s)
- R D Cone
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97201-3098, USA.
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10
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Abstract
Our understanding of body weight regulation has been greatly advanced by the characterization of previously existing mutations in mice that cause obesity. Subsequent analysis of a number of mouse knockout models has greatly expanded the number of genes known to influence adiposity by affecting metabolic rate, physical activity, and/or appetite.
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Affiliation(s)
- A A Butler
- Vollum Institute, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97201, USA
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11
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Abstract
Mutations in the melanocortin-4 receptor (MC4-R) cause obesity in both mice and humans, and the receptor is presumed to have an important role in the regulation of energy homeostasis. The MC4-R is expressed in discrete sets of neurons in the central nervous system, and thus it has been technically difficult to study the regulation of expression and the signaling mechanisms of this receptor. We report here a neuronal cell line that exhibits endogenous functional expression for the MC4-R. Initially, RT-PCR analysis showed the presence of MC4-R RNA in the hypothalamic GT1-1 and GT1-7 cells. In addition, GT1-7 cells expressed melanocortin-3 receptor while the GT1-1 subclone specifically expressed predominantly the MC4-R RNA. High-affinity binding sites were demonstrated in the GT1-1 and GT1-7 cells for NDP-alpha melanocyte-stimulating hormone (MSH; K(i) = 1.1 x 10(-10) and 1.8 x 10(-10) M) and agouti-related protein (AGRP; K(i) = 1.548 x 10(-9) and 1.663(-9) M). alpha-MSH-stimulated cAMP production in GT1-1 cells with an EC(50) of 2.2 x 10(-8) M, and cAMP production was inhibited in the presence of AGRP, an endogenous antagonist of the MC4-R. Stimulation of gonadotropin-releasing hormone (GnRH) secretion was achieved with 1 nM to 1 microM concentrations of NDP-alpha-MSH while no GnRH secretion was observed when the GT1-1 cells were treated with AGRP. The data presented here show that GT1-1 cells specifically express a functional MC4-R that couples to GnRH release.
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Affiliation(s)
- K Khong
- Vollum Institute, Oregon Health Sciences University, Portland, Oreg. 97201, USA
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12
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Haskell-Luevano C, Cone RD, Monck EK, Wan YP. Structure activity studies of the melanocortin-4 receptor by in vitro mutagenesis: identification of agouti-related protein (AGRP), melanocortin agonist and synthetic peptide antagonist interaction determinants. Biochemistry 2001; 40:6164-79. [PMID: 11352754 DOI: 10.1021/bi010025q] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In vitro mutagenesis of the mouse melanocortin-4 receptor (mMC4R) has been performed, based upon homology molecular modeling and previous melanocortin receptor mutagenesis studies that identified putative ligand-receptor interactions. Twenty-three mMC4 receptor mutants were generated and pharmacologically characterized using several melanocortin-based ligands [alpha-MSH, NDP-MSH, MTII, DNal (1')(7)-MTII, Nal(2')(7)-MTII, SHU9119, and SHU9005]. Selected mutant receptors possessing significant differences in the melanocortin-based peptide agonist and/or antagonist pharmacology were further evaluated using the endogenous antagonist agouti-related protein fragment hAGRP(83-132) and hAGRP(109-118) molecules. These studies of the mouse MC4R provide further experimental data suggesting that the conserved melanocortin receptor residues Glu92 (TM2), Asp114 (TM3), and Asp118 (TM3) (mouse MC4R numbering) are important for melanocortin-based peptide molecular recognition. Additionally, the Glu92 and Asp118 mMC4R residues are important for molecular recognition and binding of AGRP(83-132). We have identified the Phe176 (TM4), Tyr179 (TM4), Phe254 (TM6), and Phe259 (TM6) receptor residues as putatively interacting with the melanocortin-based ligand Phe(7) by differences between alpha-MSH and NDP-MSH agonist potencies. The Glu92, Asp118, and Phe253 mMC4R receptor residues appear to be critical for hAGRP(83-132) molecular recognition and binding while Phe176 appears to be important for functional antagonism of AGRP(83-132) and AGRP(109-118) but not molecular recognition. The Phe253 mMC4R residue appears to be important for AGRP(83-132) molecular recognition and general mMC4 receptor stimulation. The Phe254 and Phe259 mMC4R amino acids may participate in the differentiation of agonist versus antagonist activity of the melanocortin-based peptide antagonists SHU9119 and SHU9005, but not AGRP(83-132) or AGRP(109-118). The Met192 side chain when mutated to a Phe results in a constitutively active mMC4R that does not effect agonist ligand binding or potency. Melanocortin-based peptides modified at the 7 position of MTII with DPhe, DNal(1'), Nal(2'), and DNal(2') have been pharmacologically characterized at these mutant mouse MC4Rs. These data suggest a revised hypothesis for the mechanism of SHU9119 antagonism at the MC4R which may be attributed to the presence of a "bulky" naphthyl moiety at the 7 position (original hypothesis), and additionally that both the stereochemistry and naphthyl ring position (2' versus 1') are important for positioning of the ligand Arg(8) residue with the corresponding mMC4R amino acids.
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MESH Headings
- Agouti-Related Protein
- Amino Acid Sequence
- Animals
- Cell Line
- Humans
- Intercellular Signaling Peptides and Proteins
- Ligands
- Lysine/genetics
- Melanocyte-Stimulating Hormones/pharmacology
- Mice
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Peptide Fragments/chemical synthesis
- Peptide Fragments/metabolism
- Peptide Fragments/pharmacology
- Peptides/chemical synthesis
- Peptides/metabolism
- Peptides/pharmacology
- Phenylalanine/genetics
- Protein Binding/genetics
- Proteins/chemistry
- Proteins/metabolism
- Proteins/pharmacology
- Receptor, Melanocortin, Type 4
- Receptors, Corticotropin/antagonists & inhibitors
- Receptors, Corticotropin/chemistry
- Receptors, Corticotropin/genetics
- Receptors, Corticotropin/metabolism
- Receptors, Peptide/antagonists & inhibitors
- Receptors, Peptide/chemistry
- Receptors, Peptide/genetics
- Receptors, Peptide/metabolism
- Serine/genetics
- Structure-Activity Relationship
- Transfection
- alpha-MSH/agonists
- alpha-MSH/analogs & derivatives
- alpha-MSH/antagonists & inhibitors
- alpha-MSH/chemistry
- alpha-MSH/metabolism
- alpha-MSH/pharmacology
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Affiliation(s)
- C Haskell-Luevano
- University of Florida, Department of Medicinal Chemistry, Gainesville, Florida 32610, USA.
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13
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Cowley MA, Smart JL, Rubinstein M, Cerdán MG, Diano S, Horvath TL, Cone RD, Low MJ. Leptin activates anorexigenic POMC neurons through a neural network in the arcuate nucleus. Nature 2001; 411:480-4. [PMID: 11373681 DOI: 10.1038/35078085] [Citation(s) in RCA: 1624] [Impact Index Per Article: 70.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The administration of leptin to leptin-deficient humans, and the analogous Lepob/Lepob mice, effectively reduces hyperphagia and obesity. But common obesity is associated with elevated leptin, which suggests that obese humans are resistant to this adipocyte hormone. In addition to regulating long-term energy balance, leptin also rapidly affects neuronal activity. Proopiomelanocortin (POMC) and neuropeptide-Y types of neurons in the arcuate nucleus of the hypothalamus are both principal sites of leptin receptor expression and the source of potent neuropeptide modulators, melanocortins and neuropeptide Y, which exert opposing effects on feeding and metabolism. These neurons are therefore ideal for characterizing leptin action and the mechanism of leptin resistance; however, their diffuse distribution makes them difficult to study. Here we report electrophysiological recordings on POMC neurons, which we identified by targeted expression of green fluorescent protein in transgenic mice. Leptin increases the frequency of action potentials in the anorexigenic POMC neurons by two mechanisms: depolarization through a nonspecific cation channel; and reduced inhibition by local orexigenic neuropeptide-Y/GABA (gamma-aminobutyric acid) neurons. Furthermore, we show that melanocortin peptides have an autoinhibitory effect on this circuit. On the basis of our results, we propose an integrated model of leptin action and neuronal architecture in the arcuate nucleus of the hypothalamus.
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Affiliation(s)
- M A Cowley
- The Vollum Institute, Oregon Health Sciences University, Portland, Oregon 97201-3098, USA
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14
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Butler AA, Marks DL, Fan W, Kuhn CM, Bartolome M, Cone RD. Melanocortin-4 receptor is required for acute homeostatic responses to increased dietary fat. Nat Neurosci 2001; 4:605-11. [PMID: 11369941 DOI: 10.1038/88423] [Citation(s) in RCA: 272] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In response to moderately increased dietary fat content, melanocortin-4 receptor-null mutant (MC4R-/-) mice exhibit hyperphagia and accelerated weight gain compared to wild-type mice. An increased feed efficiency (weight gain/kcal consumed) argues that mechanisms in addition to hyperphagia are instrumental in causing weight gain. We report two specific defects in coordinating energy expenditure with food intake in MC4R-/- mice. Wild-type mice respond to an increase in the fat content of the diet by rapidly increasing diet-induced thermogenesis and by increasing physical activity, neither of which are observed in MC4R-/- mice. Leptin-deficient and MC3R-/- mice regulate metabolic rate similarly to wild-type mice in this protocol. Melanocortinergic pathways involving MC4-R-regulated neurons, which rapidly respond to signals not requiring changes in leptin, thus seem to be important in regulating metabolic and behavioral responses to dietary fat.
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MESH Headings
- Adipose Tissue, Brown/physiology
- Animals
- Crosses, Genetic
- Dietary Fats/pharmacology
- Energy Metabolism
- Feeding Behavior
- Female
- Homeostasis
- Hyperphagia/genetics
- Leptin/deficiency
- Leptin/genetics
- Leptin/physiology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Physical Exertion
- Receptor, Melanocortin, Type 3
- Receptor, Melanocortin, Type 4
- Receptors, Corticotropin/deficiency
- Receptors, Corticotropin/genetics
- Receptors, Corticotropin/physiology
- Reference Values
- Thermogenesis
- Weight Gain
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Affiliation(s)
- A A Butler
- Vollum Institute, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97201, USA
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15
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Abstract
Recent advances in our understanding of the regulation of body weight, appetite, and metabolic rate have highlighted the role of the adipose-derived hormone leptin and its receptor as fundamental modulators of these processes. Investigations of the neural targets for leptin action--as well as characterization of the agouti obesity syndrome--have, in turn, led to the discovery of fundamental neural pathways involved in the central regulation of energy homeostasis. In particular, the central melanocortin system has been shown to regulate appetite and metabolic rate in rodents; mutations in this system have been demonstrated to result in obesity in humans. Overall, the melanocortin system appears to function as a bidirectional rheostat in the regulation of energy intake and expenditure in rodents and potentially in humans. The first section of this chapter will focus on the development of our understanding of melanocortin physiology in the context of obesity. In particular, recent data regarding the interplay between melanocortin and neuropeptide Y (NPY) signaling at a cellular level will be discussed. The following section will discuss the hypothesis that melanocortin signaling plays a role in pathological weight loss and hypermetabolism observed in murine cachexia models. The potential role of this system in integrating a variety of anorexic and cachexic signals, as well as the potential for its pharmacological manipulation in the treatment of human cachexia, will be discussed.
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Affiliation(s)
- D L Marks
- Department of Pediatric Endocrinology, Oregon Health Sciences University, Portland 97201, USA
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16
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Abstract
Obesity is a health problem of epidemic proportions in the industrialized world. The cloning and characterization of the genes for the five naturally occurring monogenic obesity syndromes in the mouse have led to major breakthroughs in understanding the physiology of energy balance and the contribution of genetics to obesity in the human population. However, the regulation of energy balance is an extremely complex process, and it is quickly becoming clear that hundreds of genes are involved. In this article, we review the naturally occurring monogenic and polygenic obese mouse strains, as well as the large number of transgenic and knockout mouse models currently available for the study of obesity and energy balance.
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Affiliation(s)
- S W Robinson
- Vollum Institute, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97201, USA.
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17
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Marks DL, Ling N, Cone RD. Role of the central melanocortin system in cachexia. Cancer Res 2001; 61:1432-8. [PMID: 11245447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Individuals affected with either acute or chronic diseases often show disorders of nutrient balance. In some cases, a devastating state of malnutrition known as cachexia arises, brought about by a synergistic combination of a dramatic decrease in appetite and an increase in metabolism of fat and lean body mass. Stimulation of the hypothalamic melanocortin 4 receptor (MC4-R) produces relative anorexia and increased metabolic rate, even in a relatively starved state. Here we demonstrate that cachexia induced by lipopolysaccharide administration and by tumor growth is ameliorated by central MC4-R blockade. MC4-R knock-out mice or mice administered the MC3-R/MC4-R antagonist, agouti-related peptide, resist tumor-induced loss of lean body mass, and maintain normal circadian activity patterns during tumor growth. The final tumor mass is not affected in these animals, providing further support for the potential role of MC4-R antagonism in the treatment of cachexia in disease states.
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MESH Headings
- Agouti-Related Protein
- Animals
- Cachexia/chemically induced
- Cachexia/etiology
- Cachexia/prevention & control
- Carcinoma, Lewis Lung/complications
- Eating/drug effects
- Eating/physiology
- Intercellular Signaling Peptides and Proteins
- Lipopolysaccharides/antagonists & inhibitors
- Lipopolysaccharides/toxicity
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Motor Activity/drug effects
- Motor Activity/physiology
- Proteins/pharmacology
- Receptor, Melanocortin, Type 3
- Receptor, Melanocortin, Type 4
- Receptors, Corticotropin/antagonists & inhibitors
- Receptors, Peptide/antagonists & inhibitors
- Receptors, Peptide/genetics
- Receptors, Peptide/physiology
- Sarcoma, Experimental/complications
- Signal Transduction/physiology
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Affiliation(s)
- D L Marks
- Department of Pediatric Endocrinology, Oregon Health Sciences University, Portland 97201, USA
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18
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Butler AA, Kesterson RA, Khong K, Cullen MJ, Pelleymounter MA, Dekoning J, Baetscher M, Cone RD. A unique metabolic syndrome causes obesity in the melanocortin-3 receptor-deficient mouse. Endocrinology 2000; 141:3518-21. [PMID: 10965927 DOI: 10.1210/endo.141.9.7791] [Citation(s) in RCA: 454] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The central melanocortin system is critical for the long term regulation of energy homeostasis. Null mutations of the melanocortin-4 receptor (MC4-R) are associated with hyperphagia, obesity, and accelerated longitudinal growth in mice and humans. However, little is known about the function of another central melanocortin receptor, the MC3-R. To assess the role of the MC3-R in energy homeostasis, the majority of the mc3r coding sequence was deleted from the mouse genome. In contrast to the MC4-R knockout, which exhibits increased food intake, increased somatic growth, and defects in metabolism, mc3r-/- mice exhibit an exclusively metabolic syndrome. Homozygous null mc3r mice, while not significantly overweight, exhibit an approximately 50% to 60% increase in adipose mass. Mc3r-/- mice also exhibit an unusual increase in respiratory quotient when transferred onto high fat chow, suggesting a reduced ratio of fat/carbohydrate oxidation. Furthermore, male mc3r-/- mice also exhibit an approximately 50% reduction in locomotory behavior on the running wheel, suggesting reduced energy expenditure.
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MESH Headings
- Absorptiometry, Photon
- Adipose Tissue/metabolism
- Animals
- Calorimetry, Indirect
- Cloning, Molecular
- Diet
- Energy Metabolism/genetics
- Energy Metabolism/physiology
- Gene Targeting
- Genetic Vectors
- Male
- Mice
- Mice, Knockout
- Obesity/genetics
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptor, Melanocortin, Type 3
- Receptors, Corticotropin/deficiency
- Receptors, Corticotropin/genetics
- Reverse Transcriptase Polymerase Chain Reaction
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Affiliation(s)
- A A Butler
- Vollum Institute, Oregon Health Sciences University, Portland 97201-3098, USA
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19
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Abstract
The central melanocortin system has been demonstrated to play a pivotal role in energy homeostasis. Genetic disruption of this system causes obesity in both humans and mice. Previous experiments have shown that centrally-administered melanocortin agonists inhibit food intake and stimulate oxygen consumption. Here we report that centrally-administered melanocortin agonists also inhibit basal insulin release, and alter glucose tolerance. Furthermore, increased plasma insulin levels occur in the young lean MC4-R knockout (MC4-RKO) mouse, and impaired insulin tolerance takes place before the onset of detectable hyperphagia or obesity. These data suggest that the central melanocortin system regulates not only energy intake and expenditure, but also processes related to energy partitioning, as indicated by effects on insulin release and peripheral insulin responsiveness. Previous studies emphasize the role of excess adipose mass in the development of tissue insulin resistance, leading to type II diabetes. The data presented here show that defects in the central control of glucose homeostasis may be an additional factor in some types of obesity-associated type II diabetes.
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Affiliation(s)
- W Fan
- The Vollum Institute, Oregon Health Sciences University, Portland 97201, USA
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20
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Abstract
A study of the effects of insulin-induced hypoglycemia in the obese yellow agouti A(y) mouse was initiated to test the hypothesis that the central melanocortin pathways are required for a normal sympathetic response to hypoglycemia. An experimental protocol was performed in which young nonobese male mice were isolated and fasted beginning on day 1, then tested for glucose responses to insulin-induced hypoglycemia on day 2. Normal mice demonstrated the expected glucose rebound to hypoglycemia, exceeding baseline glucose levels by 2-3 times as a consequence of increased gluconeogenesis and glycogenolysis before returning to baseline levels. A(y) animals lacked the rebound, exhibiting instead a gradual restoration of baseline glucose levels. The results suggested a defective sympathetic response to hypoglycemia in the A(y) mouse. However, a more detailed analysis demonstrated that the lack of a hyperglycemic rebound was due to an acute inhibition of feeding specifically in the A(y) mouse, which resulted not from the hypoglycemia stressor, but rather from the stress of isolation. Handling and intraperitoneal administration of saline also specifically inhibited food intake in the A(y) but not the wild-type mouse, while restraint stress had an equivalent inhibitory effect on food intake on wild-type and A(y) mice. Since the A(y) mouse has defective hypothalamic melanocortin-4 receptor (MC4-R) signaling, these data imply that the central melanocortin pathway is necessary for regulating the effects of stress on feeding behavior. Furthermore, these data demonstrate the need for exercising extreme caution in designing experiments to analyze feeding behavior and metabolism in genetic or pharmacological models involving perturbation of the melanocortin system.
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Affiliation(s)
- J De Souza
- Vollum Institute, Oregon Health Sciences University, Portland, Oreg., USA
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21
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22
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Affiliation(s)
- R D Cone
- Vollum Institute, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97201, USA.
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23
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Affiliation(s)
- D M Dinulescu
- Vollum Institute and Department of Cell and Developmental Biology, Oregon Health Sciences University, Portland, Oregon 97201, USA
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24
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Abstract
The melanocortin system is involved in the regulation of several diverse physiological pathways, including energy homeostasis. Several synthetic peptide analogs have been designed, synthesized, and pharmacologically characterized at the mouse melanocortin receptor subtypes MC1R, MC3R, MC4R, and MC5R. These peptides incorporate modifications of the melanocortin core amino acids His-Phe-Arg-Trp by using the cyclic lactam templates of the lead structures MTII and SHU9119. Analogs containing DNal(2') at position 7 resulted in partial agonist and antagonistic activities at the mMC3R while possessing full antagonistic activities at the mMC4R. Recently, the melanocortin-5 receptor (MC5R) has been demonstrated to have a role in the regulation of exocrine gland function. This study has characterized the following analogs of SHU9119 that possess antagonist activity at the MC5R: Ac-Nle-c[Asp-(1-Me)His(6)-DNal(2')(7)-Arg-Trp-Lys]-NH(2), pA(2) = 7. 1; Ac-Nle-c[Asp-(1-Me)His(6)-DNal(2')(7)-Arg-Nal(2')(9)-Lys]-NH(2), pA(2) = 7.2; and Ac-Nle-c[Asp-Trp(6)-DNal(2')(7)-Arg-Nal(2')(9)-Lys]-NH(2), pA(2) = 6. 6.
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Affiliation(s)
- C Haskell-Luevano
- Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA.
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25
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26
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Haskell-Luevano C, Rosenquist A, Souers A, Khong KC, Ellman JA, Cone RD. Compounds that activate the mouse melanocortin-1 receptor identified by screening a small molecule library based upon the beta-turn. J Med Chem 1999; 42:4380-7. [PMID: 10543881 DOI: 10.1021/jm990190s] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A library of 951 compounds based upon the beta-turn motif were examined for their ability to stimulate the melanocortin-1 receptor. From this screening process, we have identified two compounds possessing low micromolar agonist activity at the mMC1R. The compound EL1 with racemic Nal(2') in the i + 1 position, DPro in the i + 2 position, and Trp in the i + 3 position possesses an EC(50) of 42.5 +/- 6.9 microM. Compound EL2 with Trp in the i + 1 position, DLys in the i + 2 position, and Phe in the i + 3 position possesses an EC(50) value of 63.4 +/- 26.9 microM. The results of the library screening process are consistent with a hypothesis dating back to the 1980s proposing that a beta-turn conformation involving the melanocortin "Phe-Arg-Trp" core amino acids provides the key recognition element. Additionally, these compounds represent the first nonpeptidic heterocyclic molecules reported to date that are able to activate the MC1R, a melanocyte receptor involved in skin pigmentation and animal coat coloration.
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Affiliation(s)
- C Haskell-Luevano
- Vollum Institute, Oregon Health Sciences University, Portland, Oregon 97201,USA.
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27
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Cowley MA, Pronchuk N, Fan W, Dinulescu DM, Colmers WF, Cone RD. Integration of NPY, AGRP, and melanocortin signals in the hypothalamic paraventricular nucleus: evidence of a cellular basis for the adipostat. Neuron 1999; 24:155-63. [PMID: 10677034 DOI: 10.1016/s0896-6273(00)80829-6] [Citation(s) in RCA: 489] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Energy stores are held relatively constant in many mammals. The circuitry necessary for maintaining energy homeostasis should (1) sense the amount of energy stored in adipose tissue, (2) sense and integrate the multiple opposing signals regarding nutritional state, and (3) provide output regulating energy intake and expenditure to maintain energy homeostasis. We demonstrate that individual neurons within the paraventricular nucleus of the hypothalamus (PVH) are capable of detection and integration of orexigenic (neuropeptide Y [NPY]) and anorexigenic (melanocortin) signals, that NPY and melanocortins are functional antagonists of each other within the PVH in the regulation of feeding behavior, and that melanocortin administration within the PVH regulates both feeding behavior and energy expenditure. These data provide a cellular basis for the adipostat within neurons in the PVH that appear to be jointly regulated by NPY- and melanocortin-responsive neurons.
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Affiliation(s)
- M A Cowley
- Vollum Institute, Oregon Health Sciences University, Portland 97201, USA
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28
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Abstract
Obesity is a significant health problem owing to increased risk for diabetes and cardiovascular disease, and several lines of evidence suggest that alterations in the central melanocortin system might account for some of the genetic contribution to obesity in humans. First, the phenotypic aspects and dominant inheritance of the melanocortin obesity syndromes in the mouse are more like human obesity than other murine obesity syndromes. Second, studies recently published present two rare cases of familial obesity resulting from null alleles of the proopiomelanocortin (POMC) gene, providing the first evidence that the melanocortin pathway in humans subserves the same function in regulation of energy homeostasis as it does in the rodent. Additional studies suggest that heterozygous mutations in the melanocortin 4 receptor might be a common reason for genetic predisposition to obesity in children. Research on the central melanocortin system in rodents suggests that this system might be a fundamental component of the adipostat, the mechanism by which energy stores are held relatively constant, and this hypothesis will be the focus of this review.
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Affiliation(s)
- RD Cone
- Vollum Institute, 3181 S.W. Sam Jackson Park Road, Oregon Health Sciences University, Portland, OR 97201, USA
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29
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Chen P, Li C, Haskell-Luevano C, Cone RD, Smith MS. Altered expression of agouti-related protein and its colocalization with neuropeptide Y in the arcuate nucleus of the hypothalamus during lactation. Endocrinology 1999; 140:2645-50. [PMID: 10342854 DOI: 10.1210/endo.140.6.6829] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
During lactation, the levels of neuropeptide Y (NPY), which plays an important role in mediating food intake, are significantly elevated in a number of hypothalamic areas, including the arcuate nucleus (ARH). To identify additional hypothalamic systems that might be important in mediating the increase in food intake and alterations in energy homeostasis during lactation, the present studies examined the expression of agouti-related protein (AGRP), a recently described homologue of the skin agouti protein. AGRP is found in the hypothalamus and has been suggested to play an important role in the regulation of food intake. In the first experiment, animals were studied during diestrus of the estrous cycle, a stage of the cycle when estrogen levels are basal and similar to lactation, or during days 12-13 postpartum. Lactating animals had their litters adjusted to eight pups on day 2 postpartum. Brain tissue sections were used to measure AGRP messenger RNA (mRNA) levels by in situ hybridization. AGRP mRNA signal was found mostly in the ventromedial portion of the ARH, which has been shown to contain a high density of NPY neurons. A significant increase in AGRP mRNA content was observed in the mid- to caudal portion of the ARH of lactating animals compared with diestrous females. No difference was found in the rostral portion of the ARH. In the second experiment, double-label in situ hybridization for AGRP and NPY was performed in lactating animals to determine the extent of colocalization of the two peptides in the ARH, using 35S-labeled and digoxigenin-labeled antisense complementary RNA probes. It was found that almost all of the NPY-positive neurons throughout the ARH also expressed AGRP mRNA signal. Furthermore, AGRP expression was confined almost exclusively to NPY-positive neurons. Thus, the present study showed that during lactation, AGRP gene expression was significantly elevated in a subset of the AGRP neurons in the ARH. The high degree of colocalization of AGRP and NPY, coupled with previous reports from our laboratory demonstrating increased NPY expression in the ARH in response to suckling, suggests that AGRP and NPY are coordinately regulated and may be involved in the increase in food intake during lactation.
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Affiliation(s)
- P Chen
- Division of Neuroscience, Oregon Regional Primate Research Center, Beaverton 97006, USA
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30
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Cone RD. [The central melanocortin system and its role in energy homeostasis]. Ann Endocrinol (Paris) 1999; 60:3-9. [PMID: 10374010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Obesity is an important health concern, and the central melanocortin system is likely to play an important role in both normal regulation of energy homeostasis as well as genetic predisposition to obesity. Three different mouse models of obesity have been created by virtue of mutations which alter the function of the melanocortin system, and a rare form of human obesity has been characterized in two families with mutations in the proopiomelanocortin gene [26]. More recently published works suggests an association between common childhood obesity and dominant inheritance of a single null allele of the melanocortin-4 receptor [44, 49]. Experimental work in the rodent suggests that the central melanocortin system may be a fundamental component of the adipostat, the mechanism by which constant energy stores are maintained. This hypothesis is the subject of this review.
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Affiliation(s)
- R D Cone
- Vollum Institute, Oregon Health Sciences University, Portland 97201, USA
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31
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Haskell-Luevano C, Chen P, Li C, Chang K, Smith MS, Cameron JL, Cone RD. Characterization of the neuroanatomical distribution of agouti-related protein immunoreactivity in the rhesus monkey and the rat. Endocrinology 1999; 140:1408-15. [PMID: 10067869 DOI: 10.1210/endo.140.3.6544] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Agouti-related protein (AGRP) is a recently described homolog of the skin agouti protein. AGRP is transcribed primarily in the adrenal and hypothalamus and is a high affinity antagonist of the neural melanocortin-3 and melanocortin-4 receptors. The perikarya expressing AGRP messenger RNA are found in the arcuate nucleus of the rat and rhesus monkey. Using a polyclonal antibody against the pharmacologically active domain of AGRP (amino acids 83-132), we have also characterized the distribution of AGRP-immunoreactive neurons in both species. The major fiber tracts are conserved in both species, with dense projections originating in the arcuate nucleus and proceeding along the third ventricle. Dense fiber bundles are also visible in the paraventricular, dorsomedial, and posterior nuclei in the hypothalamus, in the bed nucleus of the stria terminalis, and in the lateral septal nucleus of the septal region. AGRP-containing neurons are not visualized in a number of areas, including portions of the amygdala, thalamus, and brain stem, that express MC3-R and MC4-R messenger RNA and receive innervation from POMC neurons that serve as the source of melanocortin agonists. Thus, AGRP is most likely to be involved in modulating a conserved subset of the physiological functions of central melanocortin peptides. Based on the particular distribution of AGRP neurons, those functions are likely to include the central control of energy homeostasis.
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Affiliation(s)
- C Haskell-Luevano
- Vollum Institute, Oregon Health Sciences University, Portland 97201, USA
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32
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Abstract
Dominant black coat color in sheep is predicted to be caused by an allele ED at the extension locus. Recent studies have shown that this gene encodes the melanocyte stimulating hormone receptor (MC1-R). In mouse and fox, naturally occurring mutations in the coding region of MC1-R produce a constitutively activated receptor that switches the synthesis from phaeomelanin to eumelanin within the melanocyte, explaining the black coat color observed phenotypically. In the sheep, we have identified a Met-->Lys mutation in position 73 (M73K) together with a Asp --> Asn change at position 121 (D121N) showing complete cosegregation with dominant black coat color in a family lineage. Only the M73K mutation showed constitutive activation when introduced into the corresponding mouse receptor (mMC1-R) for pharmacological analysis; however, the position corresponding to D121 in the mouse receptor is required for high affinity ligand binding. The pharmacological profile of the M73K change is unique compared to the constitutively active E92K mutation in the sombre mouse and C123R mutation in the Alaska silver fox, indicating that the M73K change activates the receptor via a mechanism distinct from these previously characterized mutations.
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Affiliation(s)
- D I Våge
- Department of Animal Science, Agricultural University of Norway, P.O. Box 5025, N-1432 As, Norway
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33
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Dinulescu DM, Fan W, Boston BA, McCall K, Lamoreux ML, Moore KJ, Montagno J, Cone RD. Mahogany (mg) stimulates feeding and increases basal metabolic rate independent of its suppression of agouti. Proc Natl Acad Sci U S A 1998; 95:12707-12. [PMID: 9770550 PMCID: PMC22895 DOI: 10.1073/pnas.95.21.12707] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mahogany (mg) locus originally was identified as a recessive suppressor of agouti, a locus encoding a skin peptide that modifies coat color by antagonizing the melanocyte-stimulating hormone receptor or MC1-R. Certain dominant alleles of agouti cause an obesity syndrome when ectopic expression of the peptide aberrantly antagonizes the MC4-R, a related melanocyte-stimulating hormone receptor expressed in hypothalamic circuitry and involved in the regulation of feeding behavior and metabolism. Recent work has demonstrated that mg, when homozygous, blocks not only the ability of agouti to induce a yellow coat color when expressed in the skin of the lethal yellow mouse (AY), but also the obesity resulting from ectopic expression of agouti in the brain. Detailed analysis of mg/mg AY/a animals, presented here, demonstrates that mg/mg blocks the obesity, hyperinsulinemia, and increased linear growth induced by ectopic expression of the agouti peptide. Remarkably, however, mg/mg did not reduce hyperphagia in the AY/a mouse. Furthermore, mg/mg induced hyperphagia and an increase in basal metabolic rate in the C57BL/6J mouse in the absence of AY. Consequently, although mahogany is broadly required for agouti peptide action, it also appears to be involved in the control of metabolic rate and feeding behavior independent of its suppression of agouti.
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Affiliation(s)
- D M Dinulescu
- Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA
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34
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Ni XP, Kesterson RA, Sharma SD, Hruby VJ, Cone RD, Wiedemann E, Humphreys MH. Prevention of reflex natriuresis after acute unilateral nephrectomy by melanocortin receptor antagonists. Am J Physiol 1998; 274:R931-8. [PMID: 9575953 DOI: 10.1152/ajpregu.1998.274.4.r931] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
gamma-Melanocyte-stimulating hormone (gamma-MSH), atrial natriuretic peptide (ANP), and oxytocin have been identified as candidate hormonal mediators of the reflex natriuresis that follows acute unilateral nephrectomy (AUN). Pharmacological characterization of the third melanocortin receptor (MC3-R) indicates that it uniquely responds to physiological concentrations of gamma-MSH. We tested the roles of gamma-MSH, ANP, and oxytocin in the postnephrectomy natriuresis by carrying out AUN during continuous intrarenal infusion of specific antagonists for their cognate receptors. In anesthetized Sprague-Dawley rats, urinary sodium excretion (UNaV) increased from 0.34 +/- 0.04 to 1.12 +/- 0.11 mu eq/min 90 min after AUN (P < 0.001). No change in UNaV occurred in rats undergoing a sham AUN procedure. Plasma immunoreactive gamma-MSH concentration was 53 +/- 8 fmol/ml after sham AUN but 112 +/- 17 fmol/ml after AUN (P < 0.01). SHU-9119 and SHU-9005 are substituted derivatives of alpha-MSH with potent antagonism at the MC3-R in vitro. Infusion of these compounds at 5 pmol/min completely blocked the natriuretic response to AUN despite a similar elevation in plasma gamma-MSH (111 +/- 12 vs. 49 +/- 8 fmol/ml in sham rats, P < 0.01). Intrarenal infusion of the ANP receptor antagonist A-71915 (5 pmol/min) or the oxytocin receptor antagonist [d(CH2)(5)1, Tyr(Me)2,Orn8] vasotocin (10 pmol/min) effectively inhibited the natriuresis induced by intravenous infusion of ANP or oxytocin (each at 1 pmol/min), respectively, but did not block the natriuresis after AUN. Plasma immunoreactivity of these peptides was not increased after AUN. These results indicate that reflex natriuresis after AUN is accompanied by an increase in plasma gamma-MSH but not ANP or oxytocin concentration and is prevented by intrarenal infusion of receptor antagonists with selectivity for MC3-R. The data indicate that gamma-MSH or a closely related peptide mediates postnephrectomy natriuresis and provide further support for the possibility that gamma-MSH may play a wider role in sodium homeostasis.
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Affiliation(s)
- X P Ni
- Division of Nephrology, San Francisco General Hospital, University of California 94143, USA
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35
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Abstract
Dark coat color in the mouse and fox results from constitutively activated melanocortin-1 receptors. Receptor mutations in the mouse (E92K, L98P), cow (L99P), fox (C125R), and sheep (D119N) cluster near the membrane/extracellular junctions of the second and third transmembrane domains, an acidic domain that is the likely site of electrostatic interaction with an arginine residue in the ligand, alpha-MSH. For transmembrane residues E92, D119, and C125, conversion to a basic residue is required for constitutive activation. Unlike constitutively activating mutations in many G protein-coupled receptors that increase agonist efficacy and affinity, these MC1-R mutations have the opposite effect. Therefore, these mutations do not activate the receptor by directly disrupting intramolecular constraints on formation of the active high-affinity state, R*, but do so indirectly by mimicking ligand binding.
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Affiliation(s)
- D Lu
- Vollum Institute, Oregon Health Sciences University, Portland 97201, USA
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36
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Chen W, Kelly MA, Opitz-Araya X, Thomas RE, Low MJ, Cone RD. Exocrine gland dysfunction in MC5-R-deficient mice: evidence for coordinated regulation of exocrine gland function by melanocortin peptides. Cell 1997; 91:789-98. [PMID: 9413988 DOI: 10.1016/s0092-8674(00)80467-5] [Citation(s) in RCA: 372] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The effects of pituitary-derived melanocortin peptides are primarily attributed to ACTH-mediated adrenocortical glucocorticoid production. Identification of a widely distributed receptor for ACTH/MSH peptides, the melanocortin-5 receptor (MC5-R), suggested non-steroidally mediated systemic effects of these peptides. Targeted disruption of the MC5-R produced mice with a severe defect in water repulsion and thermoregulation due to decreased production of sebaceous lipids. High levels of MC5-R was found in multiple exocrine tissues, including Harderian, preputial, lacrimal, and sebaceous glands, and was also shown to be required for production and stress-regulated synthesis of porphyrins by the Harderian gland and ACTH/MSH-regulated protein secretion by the lacrimal gland. These data show a requirement for the MC5-R in multiple exocrine glands for the production of numerous products, indicative of a coordinated system for regulation of exocrine gland function by melanocortin peptides.
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Affiliation(s)
- W Chen
- Vollum Institute, Oregon Health Sciences University, Portland 97201, USA
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37
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Kunos G, Li SJ, Varga K, Archer P, Kesterson RA, Cone RD, Hruby VJ, Sharma SD. NOVEL NEURAL PATHWAYS OF CARDIOVASCULAR CONTROL BY α- AND γ-MSH. Fundam Clin Pharmacol 1997. [DOI: 10.1111/j.1472-8206.1997.tb00874.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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38
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Abstract
The lethal yellow (AY/a) mouse has a defect in proopiomelanocortin (POMC) signaling in the brain that leads to obesity, and is resistant to the anorexigenic effects of the hormone leptin. It has been proposed that the weight-reducing effects of leptin are thus transmitted primarily by way of POMC neurons. However, the central effects of defective POMC signaling, and the absence of leptin, on weight gain in double-mutant lethal yellow (AY/a) leptin-deficient (lepob/lepob) mice were shown to be independent and additive. Furthermore, deletion of the leptin gene restored leptin sensitivity to AY/a mice. This result implies that in the AY/a mouse, obesity is independent of leptin action, and resistance to leptin results from desensitization of leptin signaling.
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Affiliation(s)
- B A Boston
- Department of Pediatrics, Oregon Health Sciences University, Portland, OR 97201, USA. Laboratories, Rahway, NJ 07065, USA
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39
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Kesterson RA, Huszar D, Lynch CA, Simerly RB, Cone RD. Induction of neuropeptide Y gene expression in the dorsal medial hypothalamic nucleus in two models of the agouti obesity syndrome. Mol Endocrinol 1997; 11:630-7. [PMID: 9139806 DOI: 10.1210/mend.11.5.9921] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Dominant mutations at the agouti locus induce several phenotypic changes in the mouse including yellow pigmentation (phaeomelanization) of the coat and adult-onset obesity. Nonpigmentary phenotypic changes associated with the agouti locus are due to ectopic expression of the agouti-signaling protein (ASP), and the pheomelanizing effects on coat color are due to ASP antagonism of alpha-MSH binding to the melanocyte MC1 receptor. Recently it has been demonstrated that pharmacological antagonism of hypothalamic melanocortin receptors or genetic deletion of the melanocortin 4 receptor (MC4-R) recapitulates aspects of the agouti obesity syndrome, thus establishing that chronic disruption of central melanocortinergic signaling is the cause of agouti-induced obesity. To learn more about potential downstream effectors involved in these melanocortinergic obesity syndromes, we have examined expression of the orexigenic peptides galanin and neuropeptide Y (NPY), as well as the anorexigenic POMC in lethal yellow (A(y)), MC4-R knockout (MC4-RKO), and leptin-deficient (ob/ob) mice. No significant changes in galanin or POMC gene expression were seen in any of the obese models. In situ hybridizations using an antisense NPY probe demonstrated that in obese A(y) mice, arcuate nucleus NPY mRNA levels were equivalent to that of their C57BL/6J littermates. However, NPY was expressed at high levels in a new site, the dorsal medial hypothalamic nucleus (DMH). Expression of NPY in the DMH was also seen in obese MC4-RKO homozygous (-/-) mice, but not in lean heterozygous (+/-) or wild type (+/+) control mice. This identifies the DMH as a brain region that is functionally altered by the disruption of melanocortinergic signaling and suggests that this nucleus, possibly via elevated NPY expression, may have an etiological role in the melanocortinergic obesity syndrome.
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Affiliation(s)
- R A Kesterson
- Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University Portland, 97201-3098, USA
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40
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Abstract
Agouti and extension are two genes that control the production of yellow-red (phaeomelanin) and brown-black (eumelanin) pigments in the mammalian coat. Extension encodes the melanocyte-stimulating hormone receptor (MC1R) while agouti encodes a peptide antagonist of the receptor. In the mouse, extension is epistatic to agouti, hence dominant mutants of the MC1R encoding constitutively active receptors are not inhibited by the agouti antagonist, and animals with dominant alleles of both loci remain darkly pigmented. In the fox the proposed extension locus is not epistatic to the agouti locus. We have cloned and characterized the MC1R and the agouti gene in coat colour variants of the fox (Vulpes vulpes). A constitutively activating C125R mutation in the MC1R was found specifically in darkly pigmented animals carrying the Alaska Silver allele (EA). A deletion in the first coding exon of the agouti gene was found associated with the proposed recessive allele of agouti in the darkly pigmented Standard Silver fox (aa). Thus, as in the mouse, dark pigmentation can be caused by a constitutively active MC1R, or homozygous recessive status at the agouti locus. Our results, demonstrating the presence of dominant extension alleles in foxes with significant red coat colouration, suggest the ability of the fox agouti protein to counteract the signalling activity of a constitutively active fox MC1R.
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Affiliation(s)
- D I Våge
- Department of Animal Science, Agricultural University of Norway, As, Norway
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41
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Huszar D, Lynch CA, Fairchild-Huntress V, Dunmore JH, Fang Q, Berkemeier LR, Gu W, Kesterson RA, Boston BA, Cone RD, Smith FJ, Campfield LA, Burn P, Lee F. Targeted disruption of the melanocortin-4 receptor results in obesity in mice. Cell 1997; 88:131-41. [PMID: 9019399 DOI: 10.1016/s0092-8674(00)81865-6] [Citation(s) in RCA: 2140] [Impact Index Per Article: 79.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The melanocortin-4 receptor (MC4-R) is a G protein-coupled, seven-transmembrane receptor expressed in the brain. Inactivation of this receptor by gene targeting results in mice that develop a maturity onset obesity syndrome associated with hyperphagia, hyperinsulinemia, and hyperglycemia. This syndrome recapitulates several of the characteristic features of the agouti obesity syndrome, which results from ectopic expression of agouti protein, a pigmentation factor normally expressed in the skin. Our data identify a novel signaling pathway in the mouse for body weight regulation and support a model in which the primary mechanism by which agouti induces obesity is chronic antagonism of the MC4-R.
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Affiliation(s)
- D Huszar
- Millennium Pharmaceuticals, Inc., Cambridge, Massachusetts 02139, USA
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42
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Abstract
Dominant alleles at the agouti locus (A) cause an obesity syndrome in the mouse, as a consequence of ectopic expression of the agouti peptide. This peptide, normally only found in the skin, is a high-affinity antagonist of the melanocyte-stimulating hormone receptor (MC1-R), thus explaining the inhibitory effect of agouti on eumelanin pigment synthesis. The agouti peptide is also an antagonist of the hypothalamic melanocortin-4 receptor (MC4-R). To test the hypothesis that agouti causes obesity by antagonism of hypothalamic melanocortin receptors, we identified cyclic melanocortin analogues that are potent agonists or antagonists of the neural MC3 (refs 11, 12) and MC4 receptors. Intracerebroventricular administration of the agonist, MTII, inhibited feeding in four models of hyperphagia: fasted C57BL/6J, ob/ob, and A(Y) mice, and mice injected with neuropeptide Y. Co-administration of the specific melanocortin antagonist and agouti-mimetic SHU9119 completely blocked this inhibition. Furthermore, administration of SHU9119 significantly enhanced nocturnal feeding, or feeding stimulated by a prior fast. Our data show that melanocortinergic neurons exert a tonic inhibition of feeding behaviour. Chronic disruption of this inhibitory signal is a likely explanation of the agouti obesity syndrome.
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MESH Headings
- Agouti Signaling Protein
- Animals
- Eating
- Feeding Behavior/physiology
- Female
- Intercellular Signaling Peptides and Proteins
- Male
- Melanocyte-Stimulating Hormones/pharmacology
- Mice
- Mice, Inbred C57BL
- Mice, Obese
- Neurons/physiology
- Neuropeptide Y/metabolism
- Obesity/genetics
- Obesity/metabolism
- Proteins/genetics
- Proteins/physiology
- Receptor, Melanocortin, Type 3
- Receptor, Melanocortin, Type 4
- Receptors, Corticotropin/agonists
- Receptors, Corticotropin/antagonists & inhibitors
- Receptors, Corticotropin/metabolism
- Receptors, Peptide/agonists
- Receptors, Peptide/antagonists & inhibitors
- Receptors, Peptide/metabolism
- alpha-MSH/analogs & derivatives
- alpha-MSH/pharmacology
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Affiliation(s)
- W Fan
- The Vollum Institute for Advanced Biomedical Research, Portland, Oregon 97201, USA
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43
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Koppula SV, Robbins LS, Lu D, Baack E, White CR, Swanson NA, Cone RD. Identification of common polymorphisms in the coding sequence of the human MSH receptor (MCIR) with possible biological effects. Hum Mutat 1997; 9:30-6. [PMID: 8990005 DOI: 10.1002/(sici)1098-1004(1997)9:1<30::aid-humu5>3.0.co;2-t] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The extension locus has been identified in many mammalian species as a gene that determines the relative amounts of eumelanin and phaeomelanin pigments in hair and skin. In at least three species, this locus has been demonstrated to encode the melanocyte-stimulating hormone receptor (MC1-R), and functionally variant alleles have been demonstrated to cause a broad range of pigmentation phenotypes. To test for MC1-R allelic variation in man, genomic DNA was extracted from skin samples collected from patients with different skin types (I-VI), and eye and hair color. A PCR-based approach was used to amplify the full-length coding sequence of the MC1-R and the resulting products were sequenced. Two polymorphic alleles were identified with single point mutations in the coding sequence: a valine-to-methionine substitution at position 92 (V92M), and an aspartic acid-to-glutamic acid substitution at position 84 (D84E). RFLP analysis demonstrated the presence of the V92M allele in 4 out of 60 (6.6%) of individuals examined, predominantly those with blue eyes and blond hair. This polymorphism was found in both heterozygous and homozygous states in individuals with type I skin. The D84E allele was found in one individual with skin type I; this person also has the V92 M allele and thus is a compound heterozygote.
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Affiliation(s)
- S V Koppula
- Vollum Institute for Advanced Biomedical Research, Portland, Oregon 97201, USA
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44
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Li SJ, Varga K, Archer P, Hruby VJ, Sharma SD, Kesterson RA, Cone RD, Kunos G. Melanocortin antagonists define two distinct pathways of cardiovascular control by alpha- and gamma-melanocyte-stimulating hormones. J Neurosci 1996; 16:5182-8. [PMID: 8756446 PMCID: PMC6579284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Melanocortin peptides and at least two subtypes of melanocortin receptors (MC3-R and MC4-R) are present in brain regions involved in cardiovascular regulation. In urethane-anesthetized rats, unilateral microinjection of alpha-melanocyte-stimulating hormone (MSH) into the medullary dorsal-vagal complex (DVC) causes dose-dependent (125-250 pmol) hypotension and bradycardia, whereas gamma-MSH is less effective. The effects of alpha-MSH are inhibited by microinjection to the same site of the novel MG4-R/MC3-R antagonist SHU9119 (2-100 pmol) but not naloxone (270 pmol), whereas the similar effects of intra-DVC injection of beta-endorphin (1 pmol) are inhibited by naloxone and not by SHU9119. Hypotensive and bradycardic responses to electrical stimulation of the arcuate nucleus also are inhibited by ipsilateral intra-DVC microinjection of SHU9119. gamma-MSH and ACTH(4-10), but not alpha-MSH, elicit dose-dependent (0.1-12.5 nmol) pressor and tachycardic effects, which are much more pronounced after intracarotid than after intravenous administration. The effects of gamma-MSH (1.25 nmol) are not inhibited by the intracarotid injection of SHU9119 (1.25-12.5 nmol) or the novel MC3-R antagonist SHU9005 (1.25-12.5 nmol). We conclude that the hypotension and bradycardia elicited by the release of alpha-MSH from arcuate neurons is mediated by neural melanocortin receptors (MC4-R/MC3-R) located in the DVC, whereas the similar effects of beta-endorphin, a peptide derived from the same precursor, are mediated by opiate receptors at the same site. In contrast, neither MC3-R nor MC4-R is involved in the centrally mediated pressor and tachycardic actions of gamma-MSH, which, likely, are mediated by an as yet unidentified receptor.
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Affiliation(s)
- S J Li
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond 23298-0613, USA
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45
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Abstract
It has been known for many years that adipocytes express high affinity ACTH and alpha-melanocyte stimulating hormone (MSH) binding sites, and that ACTH, alpha-MSH, and beta-lipotropin are potent lipolytic hormones. We show here that the adipocyte response to the melanocortin peptides results from the expression of both the MC2 (ACTH) receptor as well as the newly discovered MC5 receptor. Using RT-PCR and Northern blot hybridization, high levels of MC2 receptor messenger RNA (mRNA) were found in all adipose tissues examined in the mouse, whereas MC5 receptor mRNA was found in a subset of these. Both receptors mRNAs were also found in the 3T3-L1 cell line but only after the cells had been induced to differentiate into adipocytes. This cell line was then used to characterize the pharmacological properties of the MC2 and MC5 receptor sites in situ. The MC2 receptor exhibits properties similar to the ACTH receptor characterized in adrenocortical cells, coupling to activation of adenylyl cyclase with an EC50 of approximately 1 nM. An MSH binding site characterized in these cells is presumably the MC5 receptor, based on the observation that this is the only other melanocortin receptor mRNA detected in these cells. The MC5 receptor in the 3T3-L1 adipocyte activated adenylyl cyclase in response to alpha-MSH stimulation. Interestingly, Nle4, D-Phe7-alpha-MSH (NDP-MSH), a commonly used synthetic alpha-MSH agonist, was a potent antagonist of the MC5 receptor expressed in the 3T3-L1 cell line. Although the agouti signaling peptide is a potent antagonist of NDP-MSH binding to the MC1 and MC4 melanocortin receptors, agouti was unable to block NDP-MSH binding in the 3T3-L1 adipocyte.
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Affiliation(s)
- B A Boston
- Department of Pediatrics, Oregon Health Sciences University, Portland 97201, USA
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46
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Suzuki I, Cone RD, Im S, Nordlund J, Abdel-Malek ZA. Binding of melanotropic hormones to the melanocortin receptor MC1R on human melanocytes stimulates proliferation and melanogenesis. Endocrinology 1996; 137:1627-33. [PMID: 8612494 DOI: 10.1210/endo.137.5.8612494] [Citation(s) in RCA: 194] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
alpha-Melanocyte stimulating hormone (alpha-MSH) and ACTH increase the proliferation and melanogenesis of cultured human melanocytes. To further analyze how melanotropins produce these biological effects, we investigated the regulation of the melanocortin receptor MC1R expression by alpha-MSH and ACTH using Northern blot analysis and determine the relative affinity of the receptor for the structurally similar peptides alpha-MSH, ACTH, beta-MSH, and gamma-MSH. We also determined the relative potencies of these hormones to stimulate cAMP formation, tyrosinase activity, and melanocyte proliferation. The order of affinity and potency of the noted melanotropins in these assays were alpha-MSH = ACTH > beta-MSH > gamma-MSH. Because the binding affinity of each of these melanotropins for the MC1R correlated with its ability to stimulate human melanocyte proliferation and melanogenesis, we conclude that these effects are mediated specifically by binding to and activation of the MC1R. gamma-MSH stimulated cAMP formation without affecting proliferation or melanogenesis. However, we found that relative to alpha-MSH, the effect of gamma-MSH on cAMP formation was transient. Our results suggest that alpha-MSH, ACTH, and possibly beta-MSH, but not gamma-MSH, are capable of a physiological role in regulating human pigmentation, and that melanocytes in human skin are a specific target for these hormones.
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Affiliation(s)
- I Suzuki
- Department of Dermatology, University of Cincinnati, Ohio 45267, USA
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47
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Hruby VJ, Lu D, Sharma SD, Castrucci AL, Kesterson RA, al-Obeidi FA, Hadley ME, Cone RD. Cyclic lactam alpha-melanotropin analogues of Ac-Nle4-cyclo[Asp5, D-Phe7,Lys10] alpha-melanocyte-stimulating hormone-(4-10)-NH2 with bulky aromatic amino acids at position 7 show high antagonist potency and selectivity at specific melanocortin receptors. J Med Chem 1995; 38:3454-61. [PMID: 7658432 DOI: 10.1021/jm00018a005] [Citation(s) in RCA: 295] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The cloning of the melanocyte-stimulating hormone (MSH) and adrenocorticotropic hormone (ACTH) receptors (MC1-R and MC2-R, respectively) recently has led to the identification of three additional melanocortin receptors, MC3-R, MC4-R, and MC5-R. The MC2 receptor primarily recognizes only ACTH peptides, but the other four receptors all recognize alpha-melanocyte-stimulating hormone (alpha-MSH) and potent alpha-MSH agonists such as [Nle4,D-Phe7]alpha-MSH-NH2 and Ac-Nle4-c[Asp5,D-Phe7,Lys10]alpha-MSH-(4-10)-NH2 as well as ACTH. The absence of any known physiological role for these new receptors, expressed both in the brain (MC3-R and MC4-R) and throughout a number of peripheral tissues (MC5-R), has necessitated as search for potent and receptor selective agonists and antagonists. We report here that analogues of the superpotent cyclic agonist analogue Ac-Nle4-c[Asp5,D-Phe7, Lys10]alpha-MSH-(4-10)-NH2, in which a bulky aromatic amino acid is substituted in the 7-position, can produce potent and selective antagonists for melanocortin receptors. Thus, the D-p-iodophenylalanine7-containing analogue Ac-Nle4-c[Asp5,D-Phe(pI)7,Lys10]alpha-MSH-(4-10)-NH2 is a potent antagonist (pA2 = 10.3) in the classical frog skin (Rana pipiens) assay (MC1-R), as is the D-2'-naphthylalanine7 (D-Nal(2)7)-containing analogue Ac-Nle4-c[Asp5,D-Nal(2)7,Lys10]alpha-MSH-(4-10)-NH2 (pA2 > 10.3). Interestingly, the D-p-chloro- and D-p-fluorophenylalanine7-containing analogues lacked antagonist activities at all melanotropin receptors, and both exhibited full agonist potency in the frog skin assay. The activity of these analogues also was examined at four mammalian melanocortin receptors. Interestingly, Ac-Nle4-c[Asp5,(D-Nal(2)7,Lys10] alpha-MSH-(4-10)-NH2 was found to be a potent antagonist of the MC4-R (pA2 = 9.3) with minimal agonist activity, a less potent antagonist of the MC3-R (pA2 = 8.3) with minimal agonist activity, and a full agonist of the MC1 and MC5 receptors. Surprisingly, Nle4-c[Asp5,D-Phe(pI)7,Lys10]alpha-MSH was found to be a potent agonist at the cloned human MC1-R (EC50 = 0.055 nM) and mouse MC1-R (EC50 = 0.19 nM) but had potent antagonist activities at the human MC4-R (pA2 = 9.7) and human MC3-R (pA2 = 8.3) with significant partial agonist activities (EC50 = 0.57 and 0.68 nM, respectively) as well. Thus, highly potent and receptor selective antagonist analogues can arise from substitution of the D-Phe7 residue with a bulky aromatic amino acid. These analogues can be used to help determine the functional roles of these receptors.
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Affiliation(s)
- V J Hruby
- Department of Chemistry, University of Arizona, Tucson 85721, USA
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48
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Stenzel P, Kesterson R, Yeung W, Cone RD, Rittenberg MB, Stenzel-Poore MP. Identification of a novel murine receptor for corticotropin-releasing hormone expressed in the heart. Mol Endocrinol 1995; 9:637-45. [PMID: 7565810 DOI: 10.1210/mend.9.5.7565810] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Corticotropin-releasing hormone (CRH) is the principal regulator of the stress response. CRH stimulates production of ACTH via specific CRH receptors located on pituitary corticotropes. In addition to pituitary and central nervous system effects, peripheral effects of CRH have been observed involving the immune and cardiovascular systems. Specific CRH binding studies in several peripheral organs, as well as functional studies, have implied the existence of peripheral CRH receptors. Although a pituitary/brain CRH receptor has recently been identified, it is expressed at very low levels in peripheral sites where CRH effects have been observed. We report here the identification of a novel murine CRH receptor that is highly expressed in the heart. The newly cloned CRH receptor cDNA (CRH-R2) was isolated from a mouse heart cDNA library and encodes a 430-amino acid protein containing seven putative transmembrane domains characteristic of G protein-coupled receptors. CRH-R2 is 69% identical with the previously identified murine pituitary CRH receptor and is encoded by a distinct gene. In addition to a high level of expression in the heart, weak expression was also observed in the brain and lungs. Functional studies using CRH-R2-transfected cells indicate that CRH and the CRH-related amphibian peptide, sauvagine, bind with high affinity to CRH-R2 and stimulate intracellular accumulation of cAMP.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P Stenzel
- Department of Pathology, Oregon Health Sciences University, Portland 97201, USA
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49
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Abstract
Current assays for functional activation of Gs-coupled receptors usually involve quantitation of adenylyl cyclase or measurement of cAMP concentration by radioimmunoassay. The activation of Gq-coupled receptors is commonly assayed by measurement of the production of inositol triphosphate or diacylglycerol from phosphatidylinositol 4,5-bisphosphate or of changes in intracellular calcium. These assays generally require large numbers of cells (10(5)-10(6)) and/or the use of radioactive materials. We have developed a rapid nonradioactive colorimetric assay that utilizes a beta-galactosidase (lacZ) gene fused to five copies of the cyclic AMP response element (CRE) to detect the activation of CRE-binding protein that results from an increase in intracellular cAMP or calcium. This assay can be performed using as few as 30,000 cells in a 96-well format with the end products measured simultaneously in a microplate reader. Consequently, a single individual can readily assay 1000 samples a day. Using this assay, the fold increase in beta-galactosidase activity was similar in magnitude to increases in cAMP or adenylyl cyclase activity and was approximately linear from 0.01 to 0.27 fmol/cell of intracellular cAMP. Furthermore, pharmacological characterization of one of the melanocortin receptors, mMC5-R, using this assay resulted in a similar order of potency for several melanocortin peptides to that obtained with a commonly used adenylyl cyclase enzyme assay. This assay is also useful for the characterization of Gq-coupled receptors as is demonstrated here using cells transfected with the mouse bombesin receptor. The large-scale capacity of this assay makes it an excellent method for screening molecules of interest acting on Gs- and Gq-coupled receptors.
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Affiliation(s)
- W Chen
- Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201, USA
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Radinsky R, Beltran PJ, Tsan R, Zhang R, Cone RD, Fidler IJ. Transcriptional induction of the melanocyte-stimulating hormone receptor in brain metastases of murine K-1735 melanoma. Cancer Res 1995; 55:141-8. [PMID: 7805024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Metastatic K-1735 murine melanoma cells are amelanotic in culture or in the subcutis of syngeneic mice. When injected into the internal carotid artery, these cells produce melanotic brain metastases. The production of melanin in tumor cells growing in the brain was directly correlated with induction of melanocyte-stimulating hormone receptor (MSH-R) steady-state mRNA transcripts. K-1735 cells isolated from brain lesions and implanted into the subcutis or grown in culture lose MSH-R transcripts and become amelanotic. In contrast to K-1735 cells, B16-BL6 melanoma cells constitutively produce melanin and express high levels of MSH-R mRNA regardless of the site of growth. Somatic cell hybrids between K-1735 and B16 cells produced melanin and expressed high levels of MSH-R mRNA transcripts, regardless of the site of growth, suggesting the dominance of the B16 phenotype. Treatment with alpha-MSH failed to upregulate MSH-R expression in cultured K-1735 cells or to maintain MSH-R expression in K-1735 cells isolated from brain metastases to be grown in culture. Responsiveness to alpha-MSH as determined by cell proliferation, melanin production, and intracellular accumulation of cyclic AMP directly correlated with MSH-R expression. These data demonstrate that a specific organ environment influences the phenotype of metastatic cells by regulation of specific genes that encode for cell surface receptors.
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Affiliation(s)
- R Radinsky
- Department of Cell Biology, University of Texas M. D. Anderson Cancer Center, Houston 77030
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