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Zhao Z, Yang Y, Liu P, Yan T, Li R, Pan C, Li Y, Lan X. A Critical Functional Missense Mutation (T117M) in Sheep MC4R Gene Significantly Leads to Gain-of-Function. Animals (Basel) 2024; 14:2207. [PMID: 39123733 PMCID: PMC11311007 DOI: 10.3390/ani14152207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2024] [Revised: 07/26/2024] [Accepted: 07/27/2024] [Indexed: 08/12/2024] Open
Abstract
The melanocortin 4 receptor (MC4R) gene plays a central role in regulating energy homeostasis and food intake in livestock, thereby affecting their economic worth and growth. In a previous study, the p.T117M mutation in the sheep MC4R gene, which leads to the transition of threonine to methionine, was found to affect the body weight at six months and the average daily gain in Hu sheep. However, there are still limited studies on the frequency of the sheep p.T117M missense mutation globally, and the underlying cellular mechanism remains elusive. Therefore, this study first used WGS to investigate the distribution of the MC4R gene p.T117M mutation in 652 individuals across 22 breeds worldwide. The results showed that the mutation frequency was higher in European breeds compared with Chinese sheep breeds, particularly in Poll Dorset sheep (mutation frequency > 0.5). The p.T117M mutation occurs in the first extracellular loop of MC4R. Mechanistically, the basal activity of the mutated receptor is significantly increased. Specifically, upon treatment with α-MSH and ACTH ligands, the cAMP and MAPK/ERK signaling activation of M117 MC4R is enhanced. These results indicate that the T117M mutation may change the function of the gene by increasing the constitutive activity and signaling activation of cAMP and MAPK/ERK, and, thus, may regulate the growth traits of sheep. In conclusion, this study delved into the global distribution and underlying cellular mechanisms of the T117M mutation of the MC4R gene, establishing a scientific foundation for breeding sheep with superior growth, thereby contributing to the advancement of the sheep industry.
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Affiliation(s)
| | | | | | | | | | | | - Yang Li
- College of Animal Science and Technology, Northwest A&F University, Yangling, Xianyang 712100, China; (Z.Z.); (Y.Y.); (P.L.); (T.Y.); (R.L.); (C.P.)
| | - Xianyong Lan
- College of Animal Science and Technology, Northwest A&F University, Yangling, Xianyang 712100, China; (Z.Z.); (Y.Y.); (P.L.); (T.Y.); (R.L.); (C.P.)
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2
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Yuan XC, Tao YX. Ligands for Melanocortin Receptors: Beyond Melanocyte-Stimulating Hormones and Adrenocorticotropin. Biomolecules 2022; 12:biom12101407. [PMID: 36291616 PMCID: PMC9599618 DOI: 10.3390/biom12101407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022] Open
Abstract
The discovery of melanocortins in 1916 has resulted in more than 100 years of research focused on these peptides. Extensive studies have elucidated well-established functions of melanocortins mediated by cell surface receptors, including MSHR (melanocyte-stimulating hormone receptor) and ACTHR (adrenocorticotropin receptor). Subsequently, three additional melanocortin receptors (MCRs) were identified. Among these five MCRs, MC3R and MC4R are expressed primarily in the central nervous system, and are therefore referred to as the neural MCRs. Since the central melanocortin system plays important roles in regulating energy homeostasis, targeting neural MCRs is emerging as a therapeutic approach for treating metabolic conditions such as obesity and cachexia. Early efforts modifying endogenous ligands resulted in the development of many potent and selective ligands. This review focuses on the ligands for neural MCRs, including classical ligands (MSH and agouti-related peptide), nonclassical ligands (lipocalin 2, β-defensin, small molecules, and pharmacoperones), and clinically approved ligands (ACTH, setmelanotide, bremelanotide, and several repurposed drugs).
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Affiliation(s)
- Xiao-Chen Yuan
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230061, China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA
- Correspondence:
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3
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Witkowska E, Godlewska M, Osiejuk J, Gątarz S, Wileńska B, Kosińska K, Starnowska-Sokół J, Piotrowska A, Lipiński PFJ, Matalińska J, Dyniewicz J, Halik PK, Gniazdowska E, Przewlocka B, Misicka A. Bifunctional Opioid/Melanocortin Peptidomimetics for Use in Neuropathic Pain: Variation in the Type and Length of the Linker Connecting the Two Pharmacophores. Int J Mol Sci 2022; 23:674. [PMID: 35054860 PMCID: PMC8775902 DOI: 10.3390/ijms23020674] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 01/04/2022] [Accepted: 01/06/2022] [Indexed: 01/25/2023] Open
Abstract
Based on the mechanism of neuropathic pain induction, a new type of bifunctional hybrid peptidomimetics was obtained for potential use in this type of pain. Hybrids consist of two types of pharmacophores that are connected by different types of linkers. The first pharmacophore is an opioid agonist, and the second pharmacophore is an antagonist of the pronociceptive system, i.e., an antagonist of the melanocortin-4 receptor. The results of tests in acute and neuropathic pain models of the obtained compounds have shown that the type of linker used to connect pharmacophores had an effect on antinociceptive activity. Peptidomimetics containing longer flexible linkers were very effective at low doses in the neuropathic pain model. To elucidate the effect of linker lengths, two hybrids showing very high activity and two hybrids with lower activity were further tested for affinity for opioid (mu, delta) and melanocortin-4 receptors. Their complexes with the target receptors were also studied by molecular modelling. Our results do not show a simple relationship between linker length and affinity for particular receptor types but suggest that activity in neuropathic pain is related to a proper balance of receptor affinity rather than maximum binding to any or all of the target receptors.
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Affiliation(s)
- Ewa Witkowska
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland; (M.G.); (J.O.); (S.G.); (B.W.); (K.K.)
| | - Magda Godlewska
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland; (M.G.); (J.O.); (S.G.); (B.W.); (K.K.)
| | - Jowita Osiejuk
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland; (M.G.); (J.O.); (S.G.); (B.W.); (K.K.)
| | - Sandra Gątarz
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland; (M.G.); (J.O.); (S.G.); (B.W.); (K.K.)
| | - Beata Wileńska
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland; (M.G.); (J.O.); (S.G.); (B.W.); (K.K.)
- Biological and Chemical Research Centre, University of Warsaw, 101 Zwirki i Wigury St., 02-097 Warsaw, Poland
| | - Katarzyna Kosińska
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland; (M.G.); (J.O.); (S.G.); (B.W.); (K.K.)
| | - Joanna Starnowska-Sokół
- Department of Pain Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Str., 31-343 Krakow, Poland; (J.S.-S.); (A.P.); (B.P.)
| | - Anna Piotrowska
- Department of Pain Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Str., 31-343 Krakow, Poland; (J.S.-S.); (A.P.); (B.P.)
| | - Piotr F. J. Lipiński
- Department of Neuropeptides, Mossakowski Medical Research Institute Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland; (P.F.J.L.); (J.M.); (J.D.)
| | - Joanna Matalińska
- Department of Neuropeptides, Mossakowski Medical Research Institute Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland; (P.F.J.L.); (J.M.); (J.D.)
| | - Jolanta Dyniewicz
- Department of Neuropeptides, Mossakowski Medical Research Institute Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland; (P.F.J.L.); (J.M.); (J.D.)
| | - Paweł K. Halik
- Centre of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland; (P.K.H.); (E.G.)
| | - Ewa Gniazdowska
- Centre of Radiochemistry and Nuclear Chemistry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland; (P.K.H.); (E.G.)
| | - Barbara Przewlocka
- Department of Pain Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Str., 31-343 Krakow, Poland; (J.S.-S.); (A.P.); (B.P.)
| | - Aleksandra Misicka
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland; (M.G.); (J.O.); (S.G.); (B.W.); (K.K.)
- Biological and Chemical Research Centre, University of Warsaw, 101 Zwirki i Wigury St., 02-097 Warsaw, Poland
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4
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Yeo GSH, Chao DHM, Siegert AM, Koerperich ZM, Ericson MD, Simonds SE, Larson CM, Luquet S, Clarke I, Sharma S, Clément K, Cowley MA, Haskell-Luevano C, Van Der Ploeg L, Adan RAH. The melanocortin pathway and energy homeostasis: From discovery to obesity therapy. Mol Metab 2021; 48:101206. [PMID: 33684608 PMCID: PMC8050006 DOI: 10.1016/j.molmet.2021.101206] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 02/28/2021] [Accepted: 03/03/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Over the past 20 years, insights from human and mouse genetics have illuminated the central role of the brain leptin-melanocortin pathway in controlling mammalian food intake, with genetic disruption resulting in extreme obesity, and more subtle polymorphic variations influencing the population distribution of body weight. At the end of 2020, the U.S. Food and Drug Administration (FDA) approved setmelanotide, a melanocortin 4 receptor agonist, for use in individuals with severe obesity due to either pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency. SCOPE OF REVIEW Herein, we chart the melanocortin pathway's history, explore its pharmacology, genetics, and physiology, and describe how a neuropeptidergic circuit became an important druggable obesity target. MAJOR CONCLUSIONS Unravelling the genetics of the subset of severe obesity has revealed the importance of the melanocortin pathway in appetitive control; coupling this with studying the molecular pharmacology of compounds that bind melanocortin receptors has brought a new obesity drug to the market. This process provides a drug discovery template for complex disorders, which for setmelanotide took 25 years to transform from a single gene into an approved drug.
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Affiliation(s)
- Giles S H Yeo
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | | | - Anna-Maria Siegert
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | - Zoe M Koerperich
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Mark D Ericson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Stephanie E Simonds
- Metabolism, Diabetes, and Obesity Programme, Monash Biomedicine Discovery Institute, and Department of Physiology, Monash University, Clayton, Victoria, Australia.
| | - Courtney M Larson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Serge Luquet
- Université de Paris, BFA, UMR 8251, CNRS, Paris, France.
| | - Iain Clarke
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3010, Australia.
| | | | - Karine Clément
- Assistance Publique Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, Paris, France, Sorbonne Université, INSERM, Nutrition and Obesity: Systemic Approaches (NutriOmics) Research Unit, Paris, France.
| | - Michael A Cowley
- Metabolism, Diabetes, and Obesity Programme, Monash Biomedicine Discovery Institute, and Department of Physiology, Monash University, Clayton, Victoria, Australia.
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | | | - Roger A H Adan
- Department of Translational Neuroscience, UMCU Brain Centre, University Medical Centre Utrecht, Utrecht University, the Netherlands; Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Sweden.
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5
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Differential Signaling Profiles of MC4R Mutations with Three Different Ligands. Int J Mol Sci 2020; 21:ijms21041224. [PMID: 32059383 PMCID: PMC7072973 DOI: 10.3390/ijms21041224] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/06/2020] [Accepted: 02/06/2020] [Indexed: 12/21/2022] Open
Abstract
The melanocortin 4 receptor (MC4R) is a key player in hypothalamic weight regulation and energy expenditure as part of the leptin–melanocortin pathway. Mutations in this G protein coupled receptor (GPCR) are the most common cause for monogenetic obesity, which appears to be mediated by changes in the anorectic action of MC4R via GS-dependent cyclic adenosine-monophosphate (cAMP) signaling as well as other signaling pathways. To study potential bias in the effects of MC4R mutations between the different signaling pathways, we investigated three major MC4R mutations: a GS loss-of-function (S127L) and a GS gain-of-function mutant (H158R), as well as the most common European single nucleotide polymorphism (V103I). We tested signaling of all four major G protein families plus extracellular regulated kinase (ERK) phosphorylation and β-arrestin2 recruitment, using the two endogenous agonists, α- and β-melanocyte stimulating hormone (MSH), along with a synthetic peptide agonist (NDP-α-MSH). The S127L mutation led to a full loss-of-function in all investigated pathways, whereas V103I and H158R were clearly biased towards the Gq/11 pathway when challenged with the endogenous ligands. These results show that MC4R mutations can cause vastly different changes in the various MC4R signaling pathways and highlight the importance of a comprehensive characterization of receptor mutations.
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6
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Farr OM, Mantzoros CS. Old and new tools to study human brain physiology: Current state, future directions and implications for metabolic regulation. Metabolism 2019; 99:iii-viii. [PMID: 31400385 DOI: 10.1016/j.metabol.2019.153957] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 08/05/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Olivia M Farr
- Division of Endocrinology, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA 02215, United States of America.
| | - Christos S Mantzoros
- Division of Endocrinology, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA 02215, United States of America; Section of Endocrinology, Boston VA Healthcare System/Harvard Medical School, Boston, MA 02130, United States of America
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7
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Kutz CF, Dix AL. Repository corticotropin injection in multiple sclerosis: an update. Neurodegener Dis Manag 2018; 8:217-225. [PMID: 29869572 DOI: 10.2217/nmt-2018-0008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Relapse management is a crucial component of multiple sclerosis care. Acute relapses are defined as new neurological symptoms or worsening of existing symptoms persisting for >24 h that are not attributable to heat, overexertion, or infection. The most commonly used treatment for multiple sclerosis relapse is a 3-5-day course of corticosteroids, primarily intravenous methylprednisolone with or without oral steroid taper. Repository corticotropin injection is also the US FDA-approved option for managing acute relapse, particularly in the patients with inadequate response, intolerability or allergy to corticosteroid treatment; poor venous access; or limited ability to receive home or clinic infusions.
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Affiliation(s)
- Christen F Kutz
- Colorado Springs Neurological Associates, 2312 N. Nevada Avenue, Colorado Springs, CO 80907, USA
| | - Amy L Dix
- Kansas City Multiple Sclerosis Center College Park Neurology, 10600 Mastin, Overland Park, KS 66208, USA
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8
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Ericson MD, Lensing CJ, Fleming KA, Schlasner KN, Doering SR, Haskell-Luevano C. Bench-top to clinical therapies: A review of melanocortin ligands from 1954 to 2016. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2414-2435. [PMID: 28363699 PMCID: PMC5600687 DOI: 10.1016/j.bbadis.2017.03.020] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 10/19/2022]
Abstract
The discovery of the endogenous melanocortin agonists in the 1950s have resulted in sixty years of melanocortin ligand research. Early efforts involved truncations or select modifications of the naturally occurring agonists leading to the development of many potent and selective ligands. With the identification and cloning of the five known melanocortin receptors, many ligands were improved upon through bench-top in vitro assays. Optimization of select properties resulted in ligands adopted as clinical candidates. A summary of every melanocortin ligand is outside the scope of this review. Instead, this review will focus on the following topics: classic melanocortin ligands, selective ligands, small molecule (non-peptide) ligands, ligands with sex-specific effects, bivalent and multivalent ligands, and ligands advanced to clinical trials. Each topic area will be summarized with current references to update the melanocortin field on recent progress. This article is part of a Special Issue entitled: Melanocortin Receptors - edited by Ya-Xiong Tao.
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Affiliation(s)
- Mark D Ericson
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Cody J Lensing
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Katlyn A Fleming
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Katherine N Schlasner
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Skye R Doering
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
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9
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Andersen M, Nagaev I, Meyer MK, Nagaeva O, Wikberg J, Mincheva-Nilsson L, Andersen G. Melanocortin 2, 3 and 4 Receptor Gene Expressions are Downregulated in CD8+T Cytotoxic Lymphocytes and CD19+B Lymphocytes in Rheumatoid Arthritis Responding to TNF-αInhibition. Scand J Immunol 2017; 86:31-39. [DOI: 10.1111/sji.12555] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/13/2017] [Indexed: 12/22/2022]
Affiliation(s)
- M. Andersen
- Department of Rheumatology; North Denmark Regional Hospital; Hjørring Denmark
- Department of Health Science and Technology; Aalborg University; Aalborg Denmark
| | - I. Nagaev
- Department of Clinical Microbiology; Division of Clinical Immunology; Umeå University; Umeå Sweden
| | - M. K. Meyer
- Department of Health Science and Technology; Aalborg University; Aalborg Denmark
- Centre of Clinical Science; North Denmark Regional Hospital; Hjørring Denmark
| | - O. Nagaeva
- Department of Clinical Microbiology; Division of Clinical Immunology; Umeå University; Umeå Sweden
| | - J. Wikberg
- Department of Pharmaceutical Biosciences; Uppsala University; Uppsala Sweden
| | - L. Mincheva-Nilsson
- Department of Clinical Microbiology; Division of Clinical Immunology; Umeå University; Umeå Sweden
| | - G. N. Andersen
- Department of Rheumatology; North Denmark Regional Hospital; Hjørring Denmark
- Department of Clinical Medicine; Aalborg University; Aalborg Denmark
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10
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Navarro M. The Role of the Melanocortin System in Drug and Alcohol Abuse. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2017; 136:121-150. [DOI: 10.1016/bs.irn.2017.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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11
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The melanocortin ACTH 1-39 promotes protection of oligodendrocytes by astroglia. J Neurol Sci 2016; 362:21-6. [DOI: 10.1016/j.jns.2016.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/24/2015] [Accepted: 01/04/2016] [Indexed: 11/18/2022]
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12
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Lal R, Bell S, Challenger R, Hammock V, Nyberg M, Decker D, Becker PM, Young D. Pharmacodynamics and tolerability of repository corticotropin injection in healthy human subjects: A comparison with intravenous methylprednisolone. J Clin Pharmacol 2015; 56:195-202. [PMID: 26120075 PMCID: PMC5049675 DOI: 10.1002/jcph.582] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 06/23/2015] [Indexed: 11/12/2022]
Abstract
Repository corticotropin injection (porcine adrenocorticotropic hormone [ACTH] analog) and intravenous methylprednisolone (IVMP) are used to treat inflammatory conditions such as multiple sclerosis (MS) exacerbations and rheumatoid arthritis. This multiple‐dose, randomized, crossover, open‐label study evaluated and compared pharmacodynamic outcomes in subjects who received ACTH analog (80 U subcutaneously) or IVMP (1 g) daily for 5 days. Specific outcome measures included IVMP and cortisol concentrations, total cortisol‐equivalent exposure, immune cell population changes, and tolerability. IVMP and ACTH analog increased granulocyte numbers and decreased lymphocyte counts; effects on both were significantly less pronounced with ACTH analog. Based on total cortisol‐equivalent exposure (assuming linearity), administration of 80 U of ACTH analog equates to 30 mg IVMP. Because IVMP doses significantly higher than 30 mg are usually required to treat MS exacerbations, the lower cortisol‐equivalent exposure of 80 U ACTH analog supports the hypothesis that efficacy of ACTH analog results from both steroid‐dependent and ‐independent properties. Adverse events were mild in severity; subject incidence for adverse‐event reporting was similar following both regimens. The clinical relevance of these findings in autoimmune disease populations is unknown and requires further evaluation.
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Affiliation(s)
- Ritu Lal
- Mallinckrodt Pharmaceuticals, Ellicott City, MD, USA
| | - Stacie Bell
- Mallinckrodt Pharmaceuticals, Ellicott City, MD, USA
| | | | | | - Mary Nyberg
- Mallinckrodt Pharmaceuticals, Ellicott City, MD, USA
| | - Dima Decker
- Mallinckrodt Pharmaceuticals, Ellicott City, MD, USA
| | | | - David Young
- Mallinckrodt Pharmaceuticals, Ellicott City, MD, USA
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13
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Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Spedding M, Peters JA, Harmar AJ. The Concise Guide to PHARMACOLOGY 2013/14: G protein-coupled receptors. Br J Pharmacol 2013; 170:1459-581. [PMID: 24517644 PMCID: PMC3892287 DOI: 10.1111/bph.12445] [Citation(s) in RCA: 505] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. G protein-coupled receptors are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.
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Affiliation(s)
- Stephen PH Alexander
- School of Life Sciences, University of Nottingham Medical SchoolNottingham, NG7 2UH, UK
| | - Helen E Benson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Elena Faccenda
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Adam J Pawson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Joanna L Sharman
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | | | - John A Peters
- Neuroscience Division, Medical Education Institute, Ninewells Hospital and Medical School, University of DundeeDundee, DD1 9SY, UK
| | - Anthony J Harmar
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
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14
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Temp FR, Santos AC, Marafiga JR, Jesse AC, Lenz QF, Oliveira SM, Guerra GP, Scimonelli TN, Mello CF. Alpha melanocyte stimulating hormone (α-MSH) does not modify pentylenetetrazol- and pilocarpine-induced seizures. Life Sci 2013; 93:723-31. [DOI: 10.1016/j.lfs.2013.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 08/09/2013] [Accepted: 09/04/2013] [Indexed: 12/30/2022]
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15
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Darias MJ, Andree KB, Boglino A, Fernández I, Estévez A, Gisbert E. Coordinated regulation of chromatophore differentiation and melanogenesis during the ontogeny of skin pigmentation of Solea senegalensis (Kaup, 1858). PLoS One 2013; 8:e63005. [PMID: 23671650 PMCID: PMC3650040 DOI: 10.1371/journal.pone.0063005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 03/27/2013] [Indexed: 12/23/2022] Open
Abstract
Abnormal pigmentation of Senegalese sole has been described as one problem facing the full exploitation of its commercial production. To improve our understanding of flatfish pigmentation of this commercially important species we have evaluated eleven genes related to two different processes of pigmentation: melanophore differentiation, and melanin production. The temporal distribution of gene expression peaks corresponds well with changes in pigmentation patterns and the intensity of skin melanization. Several gene ratios were also examined to put in perspective possible genetic markers for the different stages of normal pigmentation development. Further, the phenotypic changes that occur during morphogenesis correspond well with the main transitions in gene expression that occur. Given the dramatic phenotypic alterations which flatfish undergo, including the asymmetric coloration that occurs between the ocular and the blind side, and the synchrony of the two processes of morphogenesis and pigmentation ontogenesis, these species constitute an interesting model for the study of pigmentation. In this study we present a first approximation towards explaining the genetic mechanisms for regulating pigmentation ontogeny in Senegalese sole, Solea senegalensis.
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Affiliation(s)
- Maria J Darias
- Centre de Sant Carles de la Ràpita, Unitat de Cultius Experimentals, Institut de Recerca i Tecnologia Agroalimentàries, Sant Carles de la Ràpita, Catalònia, Spain.
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16
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17
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Doyle JR, Fortin JP, Beinborn M, Kopin AS. Selected melanocortin 1 receptor single-nucleotide polymorphisms differentially alter multiple signaling pathways. J Pharmacol Exp Ther 2012; 342:318-26. [PMID: 22547573 DOI: 10.1124/jpet.112.194548] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The melanocortin 1 receptor (MC1R) is a highly polymorphic G protein-coupled receptor, which is known to modulate pigmentation and inflammation. In the current study, we investigated the pharmacological effects of select single-nucleotide polymorphisms (SNPs) (V60L, R163Q, and F196L). After transient expression of MC1Rs in human embryonic kidney 293 cells, basal and ligand-induced cAMP signaling and mitogen-activated protein kinase (MAPK) activation were assessed by using luciferase reporter gene assays and Western blot analysis, respectively. All receptor variants showed decreased basal cAMP activity. With the V60L and F196L variants, the decrease in constitutive activity was attributable, at least in part, to a reduction in surface expression. The F196L variant also displayed a significant reduction in potency for both the peptide agonist α-melanocyte-stimulating hormone (α-MSH) and the small-molecule agonist 1-[1-(3-methyl-L-histidyl-O-methyl-D-tyrosyl)-4-phenyl-4-piperidinyl]-1-butanone (BMS-470539). In MAPK signaling assays, the F196L variant showed decreased phospho-extracellular signal-regulated kinase levels after stimulation with either α-MSH or BMS-470539. In contrast, the R163Q variant displayed a selective loss of α-MSH-induced MAPK activation; whereas responsiveness to the small-molecule agonist BMS-470539 was preserved. Further assessment of MC1R variants in A549 cells, an in vitro model of inflammation, revealed an enhanced inflammatory response resulting from expression of the F196L variant (versus the wild-type MC1R). This alteration in function was restored by treatment with BMS-470539. Overall, these studies illustrate novel signaling profiles linked to distinct MC1R SNPs. Furthermore, our investigations highlight the potential for small-molecule drugs to rescue the function of MC1R variants that show reduced basal and/or α-MSH stimulated activity.
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Affiliation(s)
- J R Doyle
- Molecular Pharmacology Research Center, Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
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18
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γ1- and γ2-melanocyte stimulating hormones induce central anxiogenic effects and potentiate ethanol withdrawal responses in the elevated plus-maze test in mice. Pharmacol Biochem Behav 2009; 92:267-71. [DOI: 10.1016/j.pbb.2008.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2008] [Revised: 11/19/2008] [Accepted: 12/08/2008] [Indexed: 11/17/2022]
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19
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Targeting melanocortin receptors: an approach to treat weight disorders and sexual dysfunction. Nat Rev Drug Discov 2008; 7:307-23. [PMID: 18323849 DOI: 10.1038/nrd2331] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The melanocortin system has multifaceted roles in the control of body weight homeostasis, sexual behaviour and autonomic functions, and so targeting this pathway has immense promise for drug discovery across multiple therapeutic areas. In this Review, we first outline the physiological roles of the melanocortin system, then discuss the potential of targeting melanocortin receptors by using MC3 and MC4 agonists for treating weight disorders and sexual dysfunction, and MC4 antagonists to treat anorectic and cachectic conditions. Given the complexity of the melanocortin system, we also highlight the challenges and opportunities for future drug discovery in this area.
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20
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Harmer SC, Pepper DJ, Cooke K, Bennett HPJ, Bicknell AB. Evidence of a possible role for Lys-gamma3-MSH in the regulation of adipocyte function. J Endocrinol 2008; 196:149-58. [PMID: 18180326 PMCID: PMC2216415 DOI: 10.1677/joe-07-0391] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lys-gamma3-MSH is a melanocortin peptide derived from the C-terminal of the 16 kDa fragment of POMC. The physiological role of Lys-gamma3-MSH is unclear, although it has previously been shown that, although not directly steroidogenic, it can act to potentiate the steroidogenic response of adrenal cortical cells to ACTH. This synergistic effect appears to be correlated with an ability to increase the activity of hormone sensitive lipase (HSL) and therefore the rate of cholesterol ester hydrolysis. Ligand binding studies have suggested that high-affinity binding sites for Lys-gamma3-MSH exist in the adrenal gland and a number of other rat tissues that express HSL, including adipose, skeletal muscle and testes. To investigate the hypothesis that Lys-gamma3-MSH may play a wider role in cholesterol and lipid metabolism, we tested the effect of Lys-gamma3-MSH on lipolysis, an HSL-mediated process, in 3T3-L1 adipocytes. In comparison with other melanocortin peptides, Lys-gamma3-MSH was found to be a potent stimulator of lipolysis. It was also able to phosphorylate HSL at key serine residues and stimulate the hyperphosphorylation of perilipin A. The receptor through which the lipolytic actions of Lys-gamma3-MSH are being mediated is not clear. Attempts to characterise this receptor suggest that either the pharmacology of the melanocortin receptor 5 in 3T3-L1 adipocytes is different from that described when expressed in heterologous systems or the possibility that a further, as yet uncharacterised, receptor exists.
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Affiliation(s)
- Stephen C Harmer
- School of Biological Sciences, The University of ReadingWhiteknights, PO Box 228, Reading, Berkshire RG6 6AJUK
| | - David J Pepper
- School of Biological Sciences, The University of ReadingWhiteknights, PO Box 228, Reading, Berkshire RG6 6AJUK
| | - Katy Cooke
- School of Biological Sciences, The University of ReadingWhiteknights, PO Box 228, Reading, Berkshire RG6 6AJUK
| | - Hugh P J Bennett
- Endocrine Laboratory, Royal Victoria Hospital687 Pine Avenue West, Montreal, Quebec H3A1A1Canada
| | - Andrew B Bicknell
- School of Biological Sciences, The University of ReadingWhiteknights, PO Box 228, Reading, Berkshire RG6 6AJUK
- (Correspondence should be addressed to A B Bicknell; )
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Functional characterization of two melanocortin (MC) receptors in lamprey showing orthology to the MC1 and MC4 receptor subtypes. BMC Evol Biol 2007; 7:101. [PMID: 17603878 PMCID: PMC1925065 DOI: 10.1186/1471-2148-7-101] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Accepted: 06/29/2007] [Indexed: 11/15/2022] Open
Abstract
Background The melanocortin (MC) receptors have a key role in regulating body weight and pigmentation. They belong to the rhodopsin family of G protein-coupled receptors (GPCRs). The purpose of this study was to identify ancestral MC receptors in agnathan, river lamprey. Results We report cloning of two MC receptors from river lamprey. The lamprey receptors, designated MCa and MCb, showed orthology to the MC1 and MC4 receptor subtypes, respectively. The molecular clock analysis suggested that lamprey MC receptor genes were not duplicated recently and diverged from each other more than 400 MYR ago. Expression and pharmacological characterization showed that the lamprey MCa receptor was able to bind and be activated by both lamprey and human MSH peptides. The lamprey MCa receptor had relatively high affinity for ACTH derived peptides similarly to the fish MC receptors. We found that both of the lamprey MC receptors were expressed in skin, while the MCb receptor was also found in liver, heart and skeletal muscle. Conclusion This study shows presence of MC receptors in agnathans indicating early signs of specific functions of melanocortin receptor subtypes.
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Kontijevskis A, Petrovska R, Mutule I, Uhlen S, Komorowski J, Prusis P, Wikberg JES. Proteochemometric analysis of small cyclic peptides' interaction with wild-type and chimeric melanocortin receptors. Proteins 2007; 69:83-96. [PMID: 17557335 DOI: 10.1002/prot.21461] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The melanocortin (MC) system confines unique G-protein coupled receptor pathways, which include the MC(1-5) receptors and their endogenous agonists and antagonists, the MCs and the agouti and agouti-related proteins. The MC4 receptor is an important target for development of drugs for treatment of obesity and cachexia. While natural MC peptides are selective for the MC1 receptor, some cyclic pentapeptides, such as the HS-129 peptide, show high selectivity for the MC4 receptor. Here we gained insight into the mechanisms for its recognition by MC receptors. To this end we correlated the interaction data of four HS peptide analogues with four wild-type and 14 multiple chimeric MC receptors to the binary and physicochemical descriptions of the studied entities by use of partial least squares regression, which resulted in highly valid proteochemometric models. Analysis of the models revealed that the recognition sites of the HS peptides are different from the earlier proteochemometrically mapped linear MSH peptides' recognitions sites, although they overlap partially. The analysis also revealed important amino acids that explain the selectivity of the HS-129 peptide for the MC4 receptor.
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23
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Haitina T, Takahashi A, Holmén L, Enberg J, Schiöth HB. Further evidence for ancient role of ACTH peptides at melanocortin (MC) receptors; pharmacology of dogfish and lamprey peptides at dogfish MC receptors. Peptides 2007; 28:798-805. [PMID: 17306418 DOI: 10.1016/j.peptides.2006.12.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 12/21/2006] [Accepted: 12/21/2006] [Indexed: 11/29/2022]
Abstract
The cloning of melanocortin (MC) receptors in distant species has provided us tools to get insight in how the ligand-receptors interactions in the MC system have evolved. We have however lacked studies on pharmacology of native ancient melanocortin peptides at the ancient MC receptors. In this paper we synthesized melanocortin peptides from both the sea lamprey (Petromyzon marinus) and spiny dogfish (Squalus acanthias) and tested them on the MC3 and MC4 receptors from spiny dogfish. The results show that both the dogfish and lamprey ACTH peptides have similar or higher affinity than the dogfish alpha-, beta- and gamma-MSH peptides to the dogfish MC3 and MC4 receptors. Moreover, both the dogfish and lamprey ACTH peptides have more than 10-fold higher affinity than alpha-MSH to the dogfish MC4 receptor. We also show that dogfish delta-MSH is able to bind to MC receptors and its potency is higher than of dogfish beta-MSH, which is considered to be its precursor. Our results provide the first evidence that native ACTH ligands from dogfish and lamprey have a preference above native MSH peptides to ancient version of the MC3 and MC4 receptors. This further strengthens the hypotheses that the ligand contributing to the first version of the melanocortin ligand-receptor system resembled ACTH.
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Affiliation(s)
- Tatjana Haitina
- Department of Neuroscience, Unit of Pharmacology, Uppsala University, BMC, SE 75124 Uppsala, Sweden
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24
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Wu CSJ, Greenwood DR, Cooney JM, Jensen DJ, Tatnell MA, Cooper GJS, Mountjoy KG. Peripherally administered desacetyl alpha-MSH and alpha-MSH both influence postnatal rat growth and associated rat hypothalamic protein expression. Am J Physiol Endocrinol Metab 2006; 291:E1372-80. [PMID: 16868223 DOI: 10.1152/ajpendo.00480.2005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Desacetyl alpha-MSH predominates over alpha-MSH during development, but whether it is biologically active and has a physiological role is unclear. We compared the effects of 0.3 microg.g(-1).day(-1) desacetyl alpha-MSH with that of 0.3 microg.g(-1).day(-1) alpha-MSH on postnatal body growth by administering the peptides subcutaneously daily for postnatal days 0-14 and also used a two-dimensional gel electrophoresis gel-based proteomic approach to analyze protein changes in hypothalami, the relay center for body weight and growth regulation, after 14 days of treatment. We found that the growth rate between days 1 and 10 was significantly decreased by desacetyl alpha-MSH but not by alpha-MSH, but by day 14, a time reported for development of a mature pattern of hypothalamic innervation, both peptides had significantly increased neonatal growth compared with PBS-treated control rats. Desacetyl alpha-MSH significantly increased spleen weight, but alpha-MSH had no effect. alpha-MSH significantly decreased kidney weight, but desacetyl alpha-MSH had no effect. Both desacetyl alpha-MSH and alpha-MSH significantly decreased brain weight. By 14 days, both peptides significantly changed expression of a number of hypothalamic proteins, specifically metabolic enzymes, cytoskeleton, signaling, and stress response proteins. We show that peripherally administered desacetyl alpha-MSH is biologically active and induces responses that can differ from those for alpha-MSH. In conclusion, desacetyl alpha-MSH appears to be an important regulator of neonatal rat growth.
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Affiliation(s)
- Chia-Shan Jenny Wu
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand
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25
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Ni XP, Butler AA, Cone RD, Humphreys MH. Central receptors mediating the cardiovascular actions of melanocyte stimulating hormones. J Hypertens 2006; 24:2239-46. [PMID: 17053546 DOI: 10.1097/01.hjh.0000249702.49854.fa] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Alpha and gamma-melanocyte stimulating hormones (MSH) are peptides that possess potent hypertensinogenic actions when injected intravenously or intracerebroventricularly. We sought to define the central receptor(s) mediating these cardiovascular actions. METHODS We gave bolus injections of synthetic alpha or gamma-MSH intravenously or intracerebroventricularly to anesthetized wild-type (Mc3r+/+, Mc4r+/+) mice and mice with targeted disruption of the gamma-MSH receptor (Mc3r-/-) or the melanocortin 4 receptor (Mc4r-/-). RESULTS Gamma-MSH injected intravenously increased mean arterial pressure (MAP) and heart rate (HR) dose-dependently, with the effect being evident at 10 mol/kg; the maximum increase, at 10 mol/kg, was 38 mmHg in both strains from similar control MAP. Parallel increases in HR also occurred. Injection of the sodium channel blocker, benzamil, 4 microg/kg intracerebroventricularly, before intravenous gamma-MSH completely prevented the increases in MAP and HR in both strains. Injection of 2 x 10 mol/g body weight alpha-MSH intravenously had no effect on MAP or HR in Mc4r wild-type or -/- mice. However, the same dose given intracerebroventricularly to wild-type mice increased MAP from 76 +/- 4 to 95 +/- 5 mmHg at 10 min (P < 0.01) and HR from 416 +/- 15 to 480 +/- 15 beats/min (P < 0.01). In Mc4r-/- mice, the intracerebroventricular administration of the peptide did not alter these variables, in contrast to the results in wild-type mice. CONCLUSION Both MSH peptides exert their hypertensinogenic effects through central sites of action, which probably reflect the activation of sympathetic outflow. The actions of intracerebroventricular alpha-MSH appear to be mediated via Mc4r, whereas those of gamma-MSH are independent of its receptor Mc3r, but reflect the activation of a sodium channel in the central nervous system. These results help to reconcile the hypertensive action of gamma-MSH injections with the hypertension observed in states of gamma-MSH deficiency.
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MESH Headings
- Amiloride/analogs & derivatives
- Amiloride/pharmacology
- Animals
- Blood Pressure/drug effects
- Blood Pressure/physiology
- Dose-Response Relationship, Drug
- Heart Rate/drug effects
- Heart Rate/physiology
- Hypertension/metabolism
- Hypertension/physiopathology
- Mice
- Mice, Knockout
- Models, Animal
- Receptor, Melanocortin, Type 3/genetics
- Receptor, Melanocortin, Type 3/physiology
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/physiology
- Sodium Channel Blockers/pharmacology
- Sympatholytics/pharmacology
- alpha-MSH/pharmacology
- gamma-MSH/pharmacology
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Affiliation(s)
- Xi-Ping Ni
- Division of Nephrology, San Francisco General Hospital and University of California San Francisco, San Francisco, California 94143-1341, USA
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26
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Metz JR, Peters JJM, Flik G. Molecular biology and physiology of the melanocortin system in fish: a review. Gen Comp Endocrinol 2006; 148:150-62. [PMID: 16620815 DOI: 10.1016/j.ygcen.2006.03.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Revised: 02/27/2006] [Accepted: 03/05/2006] [Indexed: 10/24/2022]
Abstract
The melanocortin system consists of melanocortin peptides derived from the proopiomelanocortin gene (in particular adrenocorticotropic hormone, ACTH, and melanocyte-stimulating hormones, MSH) and five melanocortin receptor subtypes (MC1R-MC5R). Knowledge of the melanocortin system in fish is still limited, but information on the receptor part of the system is very rapidly growing. The melanocortin receptors (MCRs) have been recently cloned from several species of fish. The amino acid sequences appear remarkably well conserved. Pharmacological characterisation studies of the first identified piscine MCRs indicate that ACTH may be the original ligand for the MCRs, while the MSH peptides gained specialised functions in the course of evolution. Considering the tissue distribution of the MCRs, there are two distinctions between mammals and fish: where in mammals the MC4R is exclusively expressed in the central nervous system, in the fish species examined so far it is also peripherally expressed. It does however, alike the situation in mammals, likely play a key role in the central regulation of food intake and energy balance. Not only the MCRs, but also many other factors involved herewith, have been found in fish and roughly appear to function similarly as in mammals. The second difference is the distribution of the MC5R, which appears less widely expressed in fish than in mammals. Considering the available data it is predicted that, in mammals and fish alike, skin colouration is mediated via MC1R and steroidogenesis via MC2R. This review provides a short overview of the basic molecular characteristics, pharmacology, and tissue distribution of the MCRs in the fish investigated up to now, as well as their physiological role in the processes of skin colouration, steroidogenesis, and feeding behaviour.
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Affiliation(s)
- Juriaan R Metz
- Department Organismal Animal Physiology, Institute for Neuroscience, University of Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
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27
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Muceniece R, Zvejniece L, Liepinsh E, Kirjanova O, Baumane L, Petrovska R, Mutulis F, Mutule I, Kalvinsh I, Wikberg JES, Dambrova M. The MC3 receptor binding affinity of melanocortins correlates with the nitric oxide production inhibition in mice brain inflammation model. Peptides 2006; 27:1443-50. [PMID: 16414147 DOI: 10.1016/j.peptides.2005.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Revised: 12/05/2005] [Accepted: 12/05/2005] [Indexed: 11/22/2022]
Abstract
Melanocortins possess strong anti-inflammatory effects acting in the central nervous system via inhibition of the production of nitric oxide (NO) during brain inflammation. To shed more light into the role of melanocortin (MC) receptor subtypes involved we synthesized and evaluated some novel peptides, modified in the melanocyte-stimulating hormone (MSH) core structure, natural MCs and known MC receptor selective peptides - MS05, MS06. Since the study included both selective, high affinity binders and the novel peptides, it was possible to do the correlation analysis of binding activities and the NO induction-related anti-inflammatory effect of the peptides. beta-MSH, gamma1-MSH, gamma2-MSH, alpha-MSH, MS05, Ac-MS06 and Ac-[Ser12]MS06 caused dose dependent inhibition of the lipopolysaccharide (LPS)-induced increase of NO overproduction in the mice forebrain whereas MSH core modified peptides Ac-[Asp9,Ser12]MS06, [Asp9]alpha-MSH and [Asp16]beta-MSH were devoid of this effect in doses up to 10 nmol per mouse. When the minimal effective dose required for inhibition of NO production was correlated with the in vitro binding activity to MC receptor subtypes a strong and significant correlation was found for the MC3 receptor (r = 0.90; p = 0.0008), whereas weak correlation was present for the other receptors. Our results suggest that the MC3 receptor is the major player in mediating the anti-inflammatory activity of MCs in the central nervous system.
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Affiliation(s)
- Ruta Muceniece
- Faculty of Medicine, University of Latvia, Sarlotes St. 1a, Riga LV-1001, Latvia.
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28
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Roberts DW, Newton RA, Beaumont KA, Helen Leonard J, Sturm RA. Quantitative analysis of MC1R gene expression in human skin cell cultures. ACTA ACUST UNITED AC 2006; 19:76-89. [PMID: 16420249 DOI: 10.1111/j.1600-0749.2005.00286.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To address the issue of melanocortin-1 receptor (MC1R) expression in non-melanocytic cells, we have quantitatively evaluated the relative expression levels of both MC1R mRNA and protein in a subset of different cell types. Using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) at high cycle numbers, we detected MC1R mRNA in all cell types examined, including human embryonic kidney-293 (HEK 293) cells, a cell type widely used as a negative control in melanocortin expression studies. Quantitative real-time PCR revealed the highest levels of MC1R transcripts were in melanocytic cells, whereas the keratinocyte and fibroblast cell cultures examined had only a low level of expression, similar to that of HEK 293 cells. Antibody mediated detection of MC1R protein in membrane extracts demonstrated exogenous receptor in MC1R transfected cell lines, as well as endogenous MC1R in melanoma cells. However, radioligand binding procedures were required to detect MC1R protein of normal human melanocytes and no surface expression of MC1R was detected in any of the non-melanocytic cells examined. This was consistent with their low level of mRNA, and suggests that, if present, the levels of surface receptor are significantly lower than that in melanocytes. The capacity of such limited levels of MC1R protein to influence non-melanocytic skin cell biology would likely be severely compromised. Indeed, the MC1R agonist [NIe(4), D-Phe(7)] alpha-melanocyte stimulating hormone (NDP-MSH) was unable to elevate intracellular cyclic adenosine monophosphate (cAMP) levels in the keratinocyte and fibroblast cells examined, whereas a robust increase was elicited in melanocytes. Although there are a variety of cell types with detectable MC1R mRNA, the expression of physiologically significant levels of the receptor may be more restricted than the current literature indicates, and within epidermal tissue may be limited to the melanocyte.
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Affiliation(s)
- Donald W Roberts
- Melanogenix Group, Institute for Molecular Bioscience, University of Queensland, Brisbane, Qld 4072, Australia
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29
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Wilkinson CW. Roles of acetylation and other post-translational modifications in melanocortin function and interactions with endorphins. Peptides 2006; 27:453-71. [PMID: 16280185 DOI: 10.1016/j.peptides.2005.05.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Accepted: 05/13/2005] [Indexed: 10/25/2022]
Abstract
Phylogenetic, developmental, anatomic, and stimulus-specific variations in post-translational processing of POMC are well established. For melanocortins, the role of alpha-N-acetylation and the selective activities of alpha, beta, and gamma forms are of special interest. Acetylation may shift the predominant activity of POMC products between endorphinergic and melanocortinergic actions-which are often in opposition. This review addresses: (1) variations in POMC processing; (2) the influence of acetylation on the functional activity of alpha-MSH; (3) state- and stimulus-dependent effects on the proportional distribution of forms of melanocortins and endorphins; (4) divergent effects of alpha-MSH and beta-endorphin administration; (5) potential roles of beta- and gamma-MSH.
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Affiliation(s)
- Charles W Wilkinson
- Geriatric Research, Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA 98108, USA.
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30
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Martin NM, Smith KL, Bloom SR, Small CJ. Interactions between the melanocortin system and the hypothalamo-pituitary-thyroid axis. Peptides 2006; 27:333-9. [PMID: 16388877 DOI: 10.1016/j.peptides.2005.01.028] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2004] [Accepted: 01/27/2005] [Indexed: 12/31/2022]
Abstract
Recent studies of transgenic mice and humans have provided compelling evidence for the importance of the hypothalamic melanocortin system in the regulation of energy balance. Energy homeostasis is a balance between food intake (energy input) and energy expenditure. The melanocortin system regulates feeding via effects of the endogenous agonist, alpha-melanocyte stimulating hormone (alpha-MSH) and the endogenous antagonist agouti-related protein (AGRP) on melanocortin 3 and 4 receptors (MC3-Rs and MC4-Rs). It has been demonstrated that the melanocortin system interacts with the hypothalamo-pituitary-thyroid (HPT) axis. Thyroid hormones influence metabolism and hence energy expenditure. Therefore, an interaction between the HPT axis and the melanocortin system would allow control of both sides of the energy balance equation, by the regulation of both energy input and energy expenditure. Here we will discuss the evidence demonstrating interactions between the melanocortin system and the HPT axis.
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Affiliation(s)
- Niamh M Martin
- Department of Metabolic Medicine, Imperial College Faculty of Medicine at Hammersmith Campus, Du Cane Road, London W12 0NN, UK
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31
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van der Salm AL, Metz JR, Bonga SEW, Flik G. Alpha-MSH, the melanocortin-1 receptor and background adaptation in the Mozambique tilapia, Oreochromis mossambicus. Gen Comp Endocrinol 2005; 144:140-9. [PMID: 16019002 DOI: 10.1016/j.ygcen.2005.05.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Revised: 05/18/2005] [Accepted: 05/19/2005] [Indexed: 10/25/2022]
Abstract
The regulation of skin darkness in vertebrates is mediated by alpha-melanophore-stimulating-hormone (alphaMSH). For this action, alphaMSH binds to the melanocortin (MC)-1 receptor, a 7-transmembrane receptor located in melanophore cell membranes. The Mozambique tilapia, Oreochromis mossambicus, can change the hue of its body in response to a change in background, a process that may involve alphaMSH and the MC1R. Scale melanophores were isolated from tilapia that were acclimatised for 25 days to a black, control grey or white background and then tested for their sensitivity to des-, mono-, and di-acetylated alphaMSH. On all backgrounds, mono-acetylated alphaMSH was the dominant isoform present in pituitary homogenates. Mono-acetylated alphaMSH also had the highest potency to disperse melanosomes. Black background adapted fish showed the highest dispersing response to alphaMSH, independent of the isoform applied. We elucidated the nucleotide and amino acid sequence of the tilapia MC1R. We show that its expression in skin does not change when tilapia are acclimatised for 25 days to a black, grey or white background, while a clear change in hue is visible. This finding, combined with the absence of differential MC1R gene expression following background acclimation indicates that the increased sensitivity to alphaMSH is most likely a result of changes in the intracellular signalling system in melanophores of black background adapted fish, rather than up-regulation of the MC1R.
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Affiliation(s)
- A L van der Salm
- Department of Animal Physiology, Institute for Neuroscience, Faculty of Science, Radboud University Nijmegen, The Netherlands
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32
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Irani BG, Haskell-Luevano C. Feeding effects of melanocortin ligands--a historical perspective. Peptides 2005; 26:1788-99. [PMID: 16046247 DOI: 10.1016/j.peptides.2004.11.038] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Accepted: 11/18/2004] [Indexed: 11/25/2022]
Abstract
The process of energy homeostasis is a highly regulated process involving interacting signals between a variety of anorexigenic and orexigenic peptides, proteins and signaling molecules. The melanocortin system is an important component of this complex regulatory network. Involvement of the melanocortin pathway in the control of food intake and body weight regulation has been studied extensively in the past two decades. Previous studies that involve central administration of melanocortin molecules and examination of molecules that effect food intake in melanocortin knockout (KO) mice (MC3R, MC4R, POMC, AGRP and NPY) have been examined. In this review, we have summarized feeding studies that have resulted in the recognition of the melanocortin system as a major contributor to the complex neuroendocrine system regulating energy homeostasis.
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Affiliation(s)
- Boman G Irani
- Department of Medicinal Chemistry, University of Florida, P.O. Box 100485, Gainesville, FL-32610, USA
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33
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Schiöth HB, Haitina T, Ling MK, Ringholm A, Fredriksson R, Cerdá-Reverter JM, Klovins J. Evolutionary conservation of the structural, pharmacological, and genomic characteristics of the melanocortin receptor subtypes. Peptides 2005; 26:1886-900. [PMID: 15985310 DOI: 10.1016/j.peptides.2004.11.034] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2004] [Accepted: 11/21/2004] [Indexed: 11/21/2022]
Abstract
We have cloned melanocortin receptors (MCRs) from several species of fish. The MC4R and MC5R subtypes arose early in vertebrate evolution and their primary structure is remarkably conserved. Expression and pharmacological characterization of the MCRs in fish has revealed that they bind and respond to melanocortin peptides with high potency. Detailed characterization of the binding properties of the different subtypes suggests that MCRs in early vertebrates had preference for adrenocorticotropic hormone (ACTH) peptides, while the high sensitivity for the shorter proopiomelanocortin (POMC) products, such as the alpha-, beta-, and gamma-melanocyte-stimulating hormone (MSH), has appeared later, perhaps as the MCR subtypes gained more specialized functions. The MCR repertoire shows in general high similarities in their primary structures, while they are however not similar in terms of functional roles. The MCRs serve therefore as an interesting model family to understand the molecular mechanisms of how functions of the genes can diverge during evolution. In this review, we provide an overview of our recent studies on the cloning, expression, pharmacology, 3D modeling, and genomic studies of the MCRs in non-mammalian species.
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Affiliation(s)
- Helgi B Schiöth
- Department of Neuroscience, Uppsala University, Biomedical Centre, Box 593, SE75124 Uppsala, Sweden.
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34
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Metz JR, Geven EJW, van den Burg EH, Flik G. ACTH, α-MSH, and control of cortisol release: cloning, sequencing, and functional expression of the melanocortin-2 and melanocortin-5 receptor in Cyprinus carpio. Am J Physiol Regul Integr Comp Physiol 2005; 289:R814-26. [PMID: 15890786 DOI: 10.1152/ajpregu.00826.2004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cortisol release from fish head kidney during the acute phase of the stress response is controlled by the adrenocorticotropic hormone (ACTH) from the pituitary pars distalis (PD). Alpha-melanocyte-stimulating hormone (α-MSH) and β-endorphin, from the pars intermedia (PI), have been implicated in cortisol release during the chronic phase. The present study addresses the regulation of cortisol release by ACTH and α-MSH in common carp ( Cyprinus carpio) and includes characterization of their receptors, namely, the melanocortin-2 and melanocortin-5 receptors (MC2R and MC5R). We could not demonstrate corticotropic activity of α-MSH, β-endorphin, and combinations of these. We do show a corticotrope in the PI, but its identity is as yet uncertain. Carp restrained for 1 and 7 days showed elevated plasma cortisol and α-MSH levels; cortisol is still elevated but lower at day 7 than day 1 of restraint. Interrenal response capacity is unaffected, as estimated by stimulation with a maximum dose ACTH in a superfusion setup. MC2R and MC5R appear phylogenetically well conserved. MC2R is predominantly expressed in head kidney; a low abundance was found in spleen and kidney. MC5R is expressed in brain, pituitary PD, kidney, and skin. Quantitative PCR analysis of MC2R and MC5R expression in the head kidney of restrained fish reveals MC2R mRNA downregulation after 7 days restraint, in line with lower plasma cortisol levels seen. We discuss regulation of corticosteroid production from a phylogenetic perspective. We propose that increased levels of α-MSH exert a positive feedback on hypothalamic corticotropin-releasing hormone release to sustain a mild stress axis activity.
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MESH Headings
- Adrenocorticotropic Hormone/metabolism
- Adrenocorticotropic Hormone/pharmacology
- Amino Acid Sequence
- Animals
- Base Sequence
- Carps
- Cloning, Molecular
- Hydrocortisone/blood
- Hydrocortisone/metabolism
- Kidney/metabolism
- Molecular Sequence Data
- Phylogeny
- Receptor, Melanocortin, Type 2/genetics
- Receptor, Melanocortin, Type 2/metabolism
- Receptors, Corticotropin/genetics
- Receptors, Corticotropin/metabolism
- Receptors, Melanocortin
- Restraint, Physical
- Stress, Physiological/etiology
- Stress, Physiological/metabolism
- Tissue Distribution
- alpha-MSH/blood
- alpha-MSH/metabolism
- alpha-MSH/pharmacology
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Affiliation(s)
- Juriaan R Metz
- Dept. Organismal Animal Physiology, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
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35
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Kopanchuk S, Veiksina S, Petrovska R, Mutule I, Szardenings M, Rinken A, Wikberg JES. Co-operative regulation of ligand binding to melanocortin receptor subtypes: Evidence for interacting binding sites. Eur J Pharmacol 2005; 512:85-95. [PMID: 15840392 DOI: 10.1016/j.ejphar.2005.02.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Revised: 01/26/2005] [Accepted: 02/18/2005] [Indexed: 11/24/2022]
Abstract
This study evaluates the binding the melanocyte stimulating hormone peptide analogue [125I]NDP-MSH to melanocortin receptors MC1, MC3, MC4 and MC5 in insect cell membranes produced by baculovirus expression systems. The presence of Ca2+ was found to be mandatory to achieve specific [125I]NDP-MSH binding to the melanocortin receptors. Although association kinetics of [125I]NDP-MSH followed the regularities of simple bimolecular reactions, the dissociation of [125I]NDP-MSH from the melanocortin receptors was heterogeneous. Eleven linear and cyclic MSH peptides studied displaced the [125I]NDP-MSH binding to the studied melanocortin receptors, with the shapes of their competition curves varying from biphasic or shallow to super-steep (Hill coefficients ranging from 0.4 to 1.5). Notably the same peptide often gave highly different patterns on different melanocortin receptor subtypes; e.g. the MC4 receptor selective antagonist HS131 gave a Hill coefficient of 1.5 on the MC1 receptor but 0.5-0.7 on the MC(3-5) receptors. Adding a mask of one of the peptides to block its high affinity binding did not prevent other competing peptides to yield biphasic competition curves. The data indicate that the binding of MSH peptides to melanocortin receptors are governed by a complex dynamic homotropic co-operative regulations.
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MESH Headings
- Animals
- Binding Sites
- Binding, Competitive/drug effects
- Calcium/pharmacology
- Cell Line
- Cell Line, Tumor
- Cell Membrane/metabolism
- Dose-Response Relationship, Drug
- Iodine Radioisotopes
- Kinetics
- Ligands
- Melanoma, Experimental/metabolism
- Melanoma, Experimental/pathology
- Peptides, Cyclic/metabolism
- Peptides, Cyclic/pharmacology
- Radioligand Assay
- Receptor, Melanocortin, Type 1/metabolism
- Receptor, Melanocortin, Type 3/metabolism
- Receptor, Melanocortin, Type 4/metabolism
- Receptors, Melanocortin/metabolism
- Spodoptera
- Time Factors
- alpha-MSH/analogs & derivatives
- alpha-MSH/metabolism
- gamma-MSH/metabolism
- gamma-MSH/pharmacology
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Affiliation(s)
- Sergei Kopanchuk
- Department of Pharmaceutical Biosciences, Uppsala University, BMC Box 591, 751 24 Uppsala, Sweden
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Mandrika I, Petrovska R, Wikberg J. Melanocortin receptors form constitutive homo- and heterodimers. Biochem Biophys Res Commun 2005; 326:349-54. [PMID: 15582585 DOI: 10.1016/j.bbrc.2004.11.036] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2004] [Indexed: 10/26/2022]
Abstract
A significant number of G protein-coupled receptors are shown to form homo- or heterodimers/oligomers, and oligomerization of GPCRs may be a quite general phenomenon. We have here explored the possibility that the two closely related human melanocortin receptor 1 (MC(1)R) and melanocortin receptor 3 (MC(3)R) form dimers. Using bioluminescence resonance energy transfer (BRET(2)) we demonstrate that MC(1) and MC(3)Rs form homo- and heterodimers, when expressed in Cos-7 cells. Treatment with agonist, partial agonist or antagonists did not modify the BRET(2) signal for any of the receptor pairs studied, suggesting that the dimerization is not regulated by ligand binding. Rather our results indicate that melanocortin receptors exist as constitutively pre-formed dimers.
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MESH Headings
- Animals
- COS Cells
- Chlorocebus aethiops
- Dimerization
- Energy Transfer
- Humans
- Ligands
- Protein Structure, Quaternary
- Radioligand Assay
- Receptor, Melanocortin, Type 1/chemistry
- Receptor, Melanocortin, Type 1/genetics
- Receptor, Melanocortin, Type 1/metabolism
- Receptor, Melanocortin, Type 3/chemistry
- Receptor, Melanocortin, Type 3/genetics
- Receptor, Melanocortin, Type 3/metabolism
- Spectrometry, Fluorescence
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Affiliation(s)
- Ilona Mandrika
- Division of Pharmacology, Department of Pharmaceutical Biosciences, Uppsala University, SE-751 24 Uppsala, Sweden
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37
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Ringholm A, Klovins J, Rudzish R, Phillips S, Rees JL, Schiöth HB. Pharmacological characterization of loss of function mutations of the human melanocortin 1 receptor that are associated with red hair. J Invest Dermatol 2004; 123:917-23. [PMID: 15482480 DOI: 10.1111/j.0022-202x.2004.23444.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Variation in skin color is the major host risk factor for melanoma and other forms of skin cancer. Individuals with red hair show an increased ratio of phaeomelanin to eumelanin in both hair and skin. This ratio is regulated by the melanocortin (MC) 1 receptor. There are several common point mutations in the human MC1 receptor that are overrepresented in North European red-heads, and in individuals with pale skin. In order to determine the functional significance of these mutations, we expressed the Asp84Glu, Val92Met, Arg163Gln, and Asp294His variants of the human MC1 receptors in eukaryotic cells and determined their ability to bind alpha-melanocyte stimulating hormone (MSH) peptides and increase intracellular cAMP. The mutants Asp84Glu and Asp294His showed a much lower response to alpha-MSH in cAMP and a slightly impaired ability to bind alpha-MSH, and the Val92Met mutant bound alpha-MSH with 100-fold lower affinity as compared with the wild-type. The Arg163Gln variant, widely found in some Asian populations, reached normal level of cAMP response but had just slightly lower potency for alpha-MSH in binding and second messenger studies. The results provide important pharmacological characterization of common MC1 receptor variants in various world populations.
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Affiliation(s)
- Aneta Ringholm
- Department of Neuroscience, Division of Pharmacology, Uppsala University, Uppsala, Sweden
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38
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Haitina T, Klovins J, Andersson J, Fredriksson R, Lagerström MC, Larhammar D, Larson ET, Schiöth HB. Cloning, tissue distribution, pharmacology and three-dimensional modelling of melanocortin receptors 4 and 5 in rainbow trout suggest close evolutionary relationship of these subtypes. Biochem J 2004; 380:475-86. [PMID: 14965341 PMCID: PMC1224171 DOI: 10.1042/bj20031934] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Revised: 02/09/2004] [Accepted: 02/13/2004] [Indexed: 11/17/2022]
Abstract
The rainbow trout (Oncorhynchus mykiss) is one of the most widely used fish species in aquaculture and physiological research. In the present paper, we report the first cloning, 3D (three-dimensional) modelling, pharmacological characterization and tissue distribution of two melanocortin (MC) receptors in rainbow trout. Phylogenetic analysis indicates that these receptors are orthologues of the human MC4 and MC5 receptors. We created 3D molecular models of these rainbow trout receptors and their human counterparts. These models suggest greater divergence between the two human receptors than between their rainbow trout counterparts. The pharmacological analyses demonstrated that ACTH (adrenocorticotropic hormone) had surprisingly high affinity for the rainbow trout MC4 and MC5 receptors, whereas alpha-, beta- and gamma-MSH (melanocyte-stimulating hormone) had lower affinity. In second-messenger studies, the cyclic MSH analogues MTII and SHU9119 acted as potent agonist and antagonist respectively at the rainbow trout MC4 receptor, indicating that these ligands are suitable for physiological studies in rainbow trout. Interestingly, we found that the rainbow trout MC4 receptor has a natural high-affinity binding site for zinc ions (0.5 microM) indicating that zinc may play an evolutionary conserved role at this receptor. Reverse transcription PCR indicates that the rainbow trout receptors are expressed both in peripheral tissues and in the central nervous system, including the telencephalon, optic tectum and hypothalamus. Overall, this analysis indicates that the rainbow trout MC4 and MC5 receptors have more in common than their mammalian counterparts, which may suggest that these two receptors have a closer evolutionary relationship than the other MC receptor subtypes.
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MESH Headings
- Amino Acid Sequence/genetics
- Animals
- Binding Sites
- Binding, Competitive
- Cell Line
- Cloning, Molecular/methods
- Evolution, Molecular
- Humans
- Kidney/chemistry
- Kidney/cytology
- Kidney/embryology
- Kidney/metabolism
- Models, Molecular
- Molecular Sequence Data
- Oncorhynchus mykiss/genetics
- Organ Specificity
- Pharmacology
- Phylogeny
- Receptor, Melanocortin, Type 4/chemistry
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Receptors, Corticotropin/chemistry
- Receptors, Corticotropin/genetics
- Receptors, Corticotropin/metabolism
- Receptors, Melanocortin
- Sequence Alignment/methods
- Sequence Analysis, DNA/methods
- Zinc/metabolism
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Affiliation(s)
- Tatjana Haitina
- Department of Neuroscience, Unit of Pharmacology, Uppsala University, BMC, Uppsala SE75124, Sweden
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39
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Lapinsh M, Veiksina S, Uhlén S, Petrovska R, Mutule I, Mutulis F, Yahorava S, Prusis P, Wikberg JES. Proteochemometric mapping of the interaction of organic compounds with melanocortin receptor subtypes. Mol Pharmacol 2004; 67:50-9. [PMID: 15470082 DOI: 10.1124/mol.104.002857] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Proteochemometrics was applied in the analysis of the binding of organic compounds to wild-type and chimeric melanocortin receptors. Thirteen chimeric melanocortin receptors were designed based on statistical molecular design; each chimera contained parts from three of the MC(1,3-5) receptors. The binding affinities of 18 compounds were determined for these chimeric melanocortin receptors and the four wild-type melanocortin receptors. The data for 14 of these compounds were correlated to the physicochemical and structural descriptors of compounds, binary descriptors of receptor sequences, and cross-terms derived from ligand and receptor descriptors to obtain a proteochemometric model (correlation was performed using partial least-squares projections to latent structures; PLS). A well fitted mathematical model (R(2) = 0.92) with high predictive ability (Q(2) = 0.79) was obtained. In a further validation of the model, the predictive ability for ligands (Q(2)lig = 0.68) and receptors (Q(2)rec = 0.76) was estimated. The model was moreover validated by external prediction by using the data for the four additional compounds that had not at all been included in the proteochemometric model; the analysis yielded a Q(2)ext = 0.73. An interpretation of the results using PLS coefficients revealed the influence of particular properties of organic compounds on their affinity to melanocortin receptors. Three-dimensional models of melanocortin receptors were also created, and physicochemical properties of the amino acids inside the receptors' transmembrane cavity were correlated to the PLS modeling results. The importance of particular amino acids for selective binding of organic compounds was estimated and used to outline the ligand recognition site in the melanocortin receptors.
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MESH Headings
- Base Sequence
- Binding Sites
- Cloning, Molecular
- DNA Primers
- Humans
- Kinetics
- Ligands
- Models, Molecular
- Organic Chemicals/metabolism
- Protein Conformation
- Receptor, Melanocortin, Type 1/chemistry
- Receptor, Melanocortin, Type 1/metabolism
- Receptor, Melanocortin, Type 3/chemistry
- Receptor, Melanocortin, Type 3/metabolism
- Receptor, Melanocortin, Type 4/chemistry
- Receptor, Melanocortin, Type 4/metabolism
- Receptors, Corticotropin/chemistry
- Receptors, Corticotropin/metabolism
- Receptors, Melanocortin
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/metabolism
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Affiliation(s)
- Maris Lapinsh
- Pharmaceutical Pharmacology, Box 591, BMC, SE751 24 Uppsala, Sweden
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40
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Ling MK, Hotta E, Kilianova Z, Haitina T, Ringholm A, Johansson L, Gallo-Payet N, Takeuchi S, Schiöth HB. The melanocortin receptor subtypes in chicken have high preference to ACTH-derived peptides. Br J Pharmacol 2004; 143:626-37. [PMID: 15466451 PMCID: PMC1575423 DOI: 10.1038/sj.bjp.0705900] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1 Melanocortin (MC) receptors are widely distributed throughout the body of chicken, like in mammals, and participate in a wide range of physiological functions. 2 To clarify the pharmacological impact of ligands acting in the MC system, we expressed the chicken MC1, MC2, MC3, MC4 and MC5 (cMC1-5) receptors in eukaryotic cells and performed comprehensive pharmacological characterization of the potency of endogenous and synthetic melanocortin peptides. 3 Remarkably, the cMC receptors displayed high affinity for ACTH-derived peptides and in general low affinity for alpha-MSH. It is evident that not only the cMC2 receptor but also the other cMC receptors interact with ACTH-derived peptide through an epitope beyond the sequence of alpha-MSH. 4 The synthetic ligand MTII was found to be a potent agonist whereas HS024 was a potent antagonist at the cMC4 receptor, indicating that these ligands are suitable for physiological studies in chicken. 5 We also show the presence of prohormone convertase 1 (PC1) and PC2 genes in chicken, and that these peptides are coexpressed with proopiomelanocortin (POMC) in various tissues.
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Affiliation(s)
- Maria K Ling
- Department of Neuroscience, Uppsala University, BMC, Box 593, 751 24 Uppsala, Sweden
| | - Eri Hotta
- Department of Biology, Faculty of Science, Okayama University, Okayama, Japan
| | - Zuzana Kilianova
- Service of Endocrinology, Department of Medicine, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Tatjana Haitina
- Department of Neuroscience, Uppsala University, BMC, Box 593, 751 24 Uppsala, Sweden
| | - Aneta Ringholm
- Department of Neuroscience, Uppsala University, BMC, Box 593, 751 24 Uppsala, Sweden
| | - Lisa Johansson
- Department of Neuroscience, Uppsala University, BMC, Box 593, 751 24 Uppsala, Sweden
| | - Nicole Gallo-Payet
- Service of Endocrinology, Department of Medicine, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | - Sakae Takeuchi
- Department of Biology, Faculty of Science, Okayama University, Okayama, Japan
| | - Helgi B Schiöth
- Department of Neuroscience, Uppsala University, BMC, Box 593, 751 24 Uppsala, Sweden
- Author for correspondence:
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41
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Humphreys MH. Gamma-MSH, sodium metabolism, and salt-sensitive hypertension. Am J Physiol Regul Integr Comp Physiol 2004; 286:R417-30. [PMID: 14761863 DOI: 10.1152/ajpregu.00365.2003] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Alpha-, beta-, and gamma-melanocyte stimulating hormones (MSHs) are melanotropin peptides that are derived from the ACTH/beta-endorphin prohormone proopiomelanocortin (POMC). They have been highly conserved through evolutionary development, although their functions in mammals have remained obscure. The identification in the last decade of a family of five membrane-spanning melanocortin receptors (MC-Rs), for which the melanotropins are the natural ligands, has permitted the characterization of a number of important actions of these peptides, although the physiological function(s) of gamma-MSH have remained elusive. Much evidence indicates that gamma-MSH stimulates sympathetic outflow and raises blood pressure through a central mechanism. However, this review focuses on newer cardiovascular and renal actions of the peptide, acting in most cases through the MC3-R. In rodents, a high-sodium diet (HSD) increases the pituitary abundance of POMC mRNA and of gamma-MSH content and results in a doubling of plasma gamma-MSH concentration. The peptide is natriuretic and acts through renal MC3-Rs, which are also upregulated by the HSD. Thus the system appears designed to participate in the integrated response to dietary sodium excess. Genetic or pharmacologic induction of gamma-MSH deficiency results in marked salt-sensitive hypertension that is corrected by the administration of the peptide, probably through a central site of action. Deletion of the MC3-R also produces salt-sensitive hypertension, which, however, is not corrected by infusion of the hormone. These observations in aggregate suggest the operation of a hormonal system important in blood pressure control and in the regulation of sodium excretion. The relationship of these two actions to each other and the significance of this system in humans are important questions for future research.
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Affiliation(s)
- Michael H Humphreys
- Division of Nephrology, San Francisco General Hospital, San Francisco, California 94143, USA.
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42
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Abstract
Differences in skin and hair color are principally genetically determined and are due to variation in the amount, type, and packaging of melanin polymers produced by melanocytes secreted into keratinocytes. Pigmentary phenotype is genetically complex and at a physiological level complicated. Genes determining a number of rare Mendelian disorders of pigmentation such as albinism have been identified, but only one gene, the melanocortin 1 receptor (MCR1), has so far been identified to explain variation in the normal population such as that leading to red hair, freckling, and sun-sensitivity. Genotype-phenotype relations of the MC1R are reviewed, as well as methods to improve the phenotypic assessment of human pigmentary status. It is argued that given advances in model systems, increases in technical facility, and the lower cost of genotype assessment, the lack of standardized phenotype assessment is now a major limit on advance.
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Affiliation(s)
- Jonathan L Rees
- Systems Group, Dermatology, University of Edinburgh, Lauriston Buildings, Lauriston Place, Edinburgh, EH3 9YW, United Kingdom.
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43
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Muceniece R, Zvejniece L, Kirjanova O, Liepinsh E, Krigere L, Baumane L, Kalvinsh I, Wikberg JES, Dambrova M. β- and γ-melanocortins inhibit lipopolysaccharide induced nitric oxide production in mice brain. Brain Res 2004; 995:7-13. [PMID: 14644465 DOI: 10.1016/j.brainres.2003.09.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The pro-opiomelanocortin-derived peptide alpha-melanocyte stimulating hormone (alpha-MSH) mediates many diverse physiological actions, including anti-inflammatory and immunomodulatory effects. However, little is known about the physiological roles of the other melanocortins, beta- and gamma-MSH. Here, we investigated the effects of melanocortin peptides in an in vivo neuroinflammation model. Six hours following intracisternal (i.c.) administration of 10 microg lipopolysaccharide (LPS) to mice a five-fold increase in the nitric oxide (NO) level was seen in the animals' brains, when detected by electron paramagnetic resonance (EPR). All tested melanocortins, alpha-, beta-, gamma1- and gamma2-MSH (0.001-10 nmol/mouse i.c.), dose dependently reduced the LPS induced increases in brain NO, with an order of effectiveness: beta-MSH > or = gamma1-MSH=gamma2-MSH>alpha-MSH. Our results suggest specialized functions of beta- and gamma-MSH melanocortins in inflammatory signal modulation in the brain.
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Affiliation(s)
- Ruta Muceniece
- Department of Pharmacy, Faculty of Medicine, University of Latvia, Sarlotes iela la, 1001 Riga, Latvia.
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Klovins J, Haitina T, Fridmanis D, Kilianova Z, Kapa I, Fredriksson R, Gallo-Payet N, Schiöth HB. The melanocortin system in Fugu: determination of POMC/AGRP/MCR gene repertoire and synteny, as well as pharmacology and anatomical distribution of the MCRs. Mol Biol Evol 2003; 21:563-79. [PMID: 14694081 DOI: 10.1093/molbev/msh050] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The G-protein-coupled melanocortin receptors (MCRs) play an important role in a variety of essential functions such as the regulation of pigmentation, energy homeostasis, and steroid production. We performed a comprehensive characterization of the MC system in Fugu (Takifugu rubripes). We show that Fugu has an AGRP gene with high degree of conservation in the C-terminal region in addition to a POMC gene lacking gamma-MSH. The Fugu genome contains single copies of four MCRs, whereas the MC3R is missing. The MC2R and MC5R are found in tandem and remarkably contain one and two introns, respectively. We suggest that these introns were inserted through a reverse splicing mechanism into the DRY motif that is widely conserved through GPCRs. We were able to assemble large blocks around the MCRs in Fugu, showing remarkable synteny with human chromosomes 16 and 18. Detailed pharmacological characterization showed that ACTH had surprisingly high affinity for the Fugu MC1R and MC4R, whereas alpha-MSH had lower affinity. We also showed that the MC2R gene in Fugu codes for an ACTH receptor, which did not respond to alpha-MSH. All the Fugu receptors were able to couple functionally to cAMP production in line with the mammalian orthologs. The anatomical characterization shows that the MC2R is expressed in the brain in addition to the head-kidney, whereas the MC4R and MC5R are found in both brain regions and peripheral tissues. This is the first comprehensive genomic and functional characterization of a GPCR family within the Fugu genome. The study shows that some parts of the MC system are highly conserved through vertebrate evolution, such as regions in POMC coding for ACTH, alpha-MSH, and beta-MSH, the C-terminal region of AGRP, key binding units within the MC1R, MC2R, MC4R, and MC5R, synteny blocks around the MCRs, pharmacological properties of the MC2R, whereas other parts in the system are either missing, such as the MC3R and gamma-MSH, or different as compared to mammals, such as the affinity of ACTH and MSH peptides to MC1R and MC4R and the anatomical expression pattern of the MCRs.
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Affiliation(s)
- Janis Klovins
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
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Böhm M, Raghunath M, Sunderkötter C, Schiller M, Ständer S, Brzoska T, Cauvet T, Schiöth HB, Schwarz T, Luger TA. Collagen metabolism is a novel target of the neuropeptide alpha-melanocyte-stimulating hormone. J Biol Chem 2003; 279:6959-66. [PMID: 14645373 DOI: 10.1074/jbc.m312549200] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Suppression of collagen synthesis is a major therapeutic goal in the treatment of fibrotic disorders. We show here that alpha-melanocyte-stimulating hormone (alpha-MSH), a neuropeptide well known for its pigment-inducing capacity, modulates collagen synthesis and deposition. Alpha-MSH in vitro suppresses the synthesis of collagen types I, III, and V and down-regulates the secretion of procollagen type I C-terminal peptide (PICP) in human dermal fibroblasts treated with the fibrogenic cytokine transforming growth factor-beta1 (TGF-beta1). Alpha-MSH did not interfere with TGF-beta1 signaling, because TGF-beta1-induced expression of collagen mRNA was not affected, implying a posttranscriptional mechanism. Human dermal fibroblasts in vitro express a high affinity binding site for MSH, which was identified by reverse transcription PCR and immunofluorescence analysis as the melanocortin-1 receptor (MC-1R). Immunohistochemical studies on normal adult human skin confirmed MC-1R expression in distinct dermal fibroblastic cells. The MC-1R on fibroblasts appears to be functionally relevant because alpha-MSH increased the amount of intracellular cAMP, and coincubation with a synthetic peptide corresponding to the human Agouti signaling protein abrogated the inhibition of TGF-beta1-induced PICP secretion by alpha-MSH. To assess the in vivo relevance of these findings, a mouse model was used in which dermal fibrosis was induced by repetitive intracutaneous injections with TGF-beta1. The inductive activity of TGF-beta1 on collagen deposition and the number of dermal cells immunoreactive for vimentin and alpha-smooth muscle actin was significantly suppressed by injection of alpha-MSH. Melanocortins such as alpha-MSH may therefore represent a novel class of modulators with potential usefulness for the treatment of fibrotic disorders.
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Affiliation(s)
- Markus Böhm
- Department of Dermatology and the Ludwig Boltzmann Institute for Cell Biology and Immunobiology of the Skin, University of Münster, 48149 Münster, Germany.
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Goetz AS, Ignar DM. Characterization of melanocortin receptors. CURRENT PROTOCOLS IN PHARMACOLOGY 2003; Chapter 1:Unit1.28. [PMID: 21956799 DOI: 10.1002/0471141755.ph0128s22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This unit describes a Scintillation Proximity Assay (SPA) for the measurement of ligand binding to melanocortin receptors (MCRs) using membranes prepared from cell lines stably expressing recombinant MCRs. It provides a facile method for determining the affinity of compounds at MC1R, MC3R, MC4R, or MC5R.
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Affiliation(s)
- Aaron S Goetz
- GlaxoSmithKline, Research Triangle Park, North Carolina, USA
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Muceniece R, Krigere L, Süli-Vargha H, Wikberg JES. Effects of alpha-melanotropin C-terminal tripeptide analogues on macrophage NO production. Peptides 2003; 24:701-7. [PMID: 12895656 DOI: 10.1016/s0196-9781(03)00128-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The C-terminal tripeptide of melanocyte-stimulating hormone, MSH (11-13) (Lys-Pro-Val), possesses strong anti-inflammatory actions, which are mediated via mechanisms that are not fully understood. To shed more light into these mechanisms we have here synthesised and evaluated the activities of L- and D-Val substituted cyclic modifications of MSH (11-13) on nitric oxide (NO) in macrophage RAW 264.7 cells, as well as on binding to melanocortin receptors (MCRs) in B16-F1 and MCR expressing insect cells, and for effects on cAMP. MSH (11-13) and its analogues did neither bind to MCRs nor stimulate cAMP in RAW 264.7 and B16-F1 cells, except H-, which showed a tendency to increase cAMP at high (10-100 microM) concentrations. However, all investigated peptides dose dependently inhibited NO in LPS/IFN-gamma-stimulated RAW 264.7, cells with a structure activity relationship suggesting the existence of a distinct receptive site. This site appears to be distinct from the MCRs and not linked with cAMP.
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Affiliation(s)
- Ruta Muceniece
- Faculty of Medicine, University of Latvia, Sarlotes iela 1a, LV-1001 Riga, Latvia.
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Schiöth HB, Kask A, Mutulis F, Muceniece R, Mutule I, Mutule I, Mandrika I, Wikberg JES. Novel selective melanocortin 4 receptor antagonist induces food intake after peripheral administration. Biochem Biophys Res Commun 2003; 301:399-405. [PMID: 12565874 DOI: 10.1016/s0006-291x(02)03065-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We synthesized a new series of small cyclic melanocyte-stimulating hormone (MSH) analogues and screened them for binding affinity at the four MSH binding melanocortin (MC) receptors. We identified a novel substance HS131, with about 20-fold higher affinity for the MC4 receptor than the MC3 receptor. This substance proved to be antagonist for all the four MC receptors in a cAMP assay. HS131 is a six amino acid long peptide, has a molecular weight below 1000, and has only two amino acids in common with the natural MSH peptides. HS131 potently and dose dependently increased food intake after i.c.v. administration. Moreover, s.c. administration of HS131 (1.0 mg/kg) increased food intake, suggesting that HS131 may be able to pass the blood brain barrier. This cyclic low molecular weight peptidomimetic will enable studies of the functional role of the MC4 receptors by peripheral administration and it may be used as a template for further development of low molecular weight substances for the MC receptors.
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Affiliation(s)
- Helgi B Schiöth
- Department of Neuroscience, Uppsala University, BMC, Box 593, 751 24 Uppsala, Sweden.
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Schiöth HB, Tesfaye A, Mutulis F, Rudzish R, Mutule I, Muceniece R, Watanobe H, Wikberg JES. Subtype selective binding properties of substituted linear melanocyte stimulating hormone analogues. Neuropeptides 2002; 36:427-34. [PMID: 12507437 DOI: 10.1016/s0143-4179(02)00133-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The melanocortin receptors are peptide binding G-protein coupled receptors that play a role in important physiological functions such as energy balance, inflammatory processes and several aspects of reproduction. In this study, we synthesised 11 new linear MSH analogues and tested their binding to the human MC receptors (MC1, MC3, MC4 and MC5) expressed in COS cells. Our results show that introduction of Asp in position 4 similarly affects the binding to the MC1, MC4 and MC5 receptors, but drastically lowers the binding to the MC3 receptor. Arg(5) substitution shows relatively high affinity for the MC4 receptor, while the results also give further support for specific importance of His(6) for the MC1 receptor. Introduction of Asp in position 10, mimicking gamma-MSH, decreased the affinity for the MC3 receptor in similar manner as for the MC4 receptor, suggesting that there are important differences in the binding conformation of gamma-MSH and NPD-MSH. Our results provide further information about the ligand binding requirements for each of the MC receptor subtypes, and highlights differential influence of the core residues in the MSH peptides. The data set also provides useful information for further calculations and modeling of MC receptor binders.
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Affiliation(s)
- Helgi B Schiöth
- Department of Neuroscience, Biomedical Center, Uppsala University, Box 593, Uppsala 751 24, Sweden.
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Ringholm A, Fredriksson R, Poliakova N, Yan YL, Postlethwait JH, Larhammar D, Schiöth HB. One melanocortin 4 and two melanocortin 5 receptors from zebrafish show remarkable conservation in structure and pharmacology. J Neurochem 2002; 82:6-18. [PMID: 12091460 DOI: 10.1046/j.1471-4159.2002.00934.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We report the cloning, genome mapping, functional expression, pharmacology and anatomical distribution of three melanocortin (MC) receptors from zebrafish (z). Phylogenetic analysis showed with high bootstrap support that these genes represent one MC4 receptor and two MC5 receptors. Chromosomal mapping showed conserved synteny between regions containing zMC4 and human (h) MC4 receptors, whereas the two zMC5 receptor genes map on chromosome segments in which the zebrafish has several genes with two orthologues of a single mammalian gene. It is likely that the two copies of zMC5 receptors arose through a separate duplication in the teleost lineage. The zMC4, zMC5a, and zMC5b receptors share 70-71% overall amino acid identity with the respective human orthologues and over 90% in three TM regions believed to be most important for ligand binding. All three zebrafish receptors also show pharmacological properties remarkably similar to their human orthologues, with similar affinities and the same potency order, when expressed and characterized in radioligand binding assay for the natural MSH) peptides alpha-, beta-, and gamma-MSH. Stimulation of transfected mammalian cells with alpha-MSH caused a dose-dependent increase in intracellular cAMP levels for all three zebrafish receptors. All three genes were expressed in the brain, eye, ovaries and gastrointestinal tract, whereas the zMC5b receptor was also found in the heart, as determined by RT-PCR. Our studies, which represent the first characterization of MC receptors in a nonamniote species, indicate that the MC receptor subtypes arose very early in vertebrate evolution. Important pharmacological and functional properties, as well as gene structure and syntenic relationships have been highly conserved over a period of more than 400 million years implying that these receptors participate in vital physiological functions.
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MESH Headings
- Animals
- Binding, Competitive
- Biological Assay
- Blotting, Southern
- Cell Line
- Chromosome Mapping
- Cloning, Molecular
- Conserved Sequence
- Humans
- Ligands
- Molecular Sequence Data
- Organ Specificity
- Phylogeny
- Radioligand Assay
- Receptor, Melanocortin, Type 4
- Receptors, Corticotropin/biosynthesis
- Receptors, Corticotropin/chemistry
- Receptors, Corticotropin/genetics
- Receptors, Melanocortin
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Homology, Amino Acid
- Zebrafish
- Zebrafish Proteins/biosynthesis
- Zebrafish Proteins/chemistry
- Zebrafish Proteins/genetics
- alpha-MSH/analogs & derivatives
- alpha-MSH/pharmacokinetics
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Affiliation(s)
- Aneta Ringholm
- Department of Neuroscience, Unit of Pharmacology, Uppsala University, BMC, 75 124 Uppsala, Sweden
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