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Abstract
The 5 known melanocortin receptors (MCs) have established physiological roles. With the exception of MC2, these receptors can behave unpredictably, and since they are more widely expressed than their established roles would suggest, it is likely that they have other poorly characterized functions. The aim of this review is to discuss some of the less well-explored aspects of the 4 enigmatic members of this receptor family (MC1,3-5) and describe how these are multifaceted G protein-coupled receptors (GPCRs). These receptors appear to be promiscuous in that they bind several endogenous agonists (products of the proopiomelanocortin [POMC] gene) and antagonists but with inconsistent relative affinities and effects. We propose that this is a result of posttranslational modifications that determine receptor localization within nanodomains. Within each nanodomain there will be a variety of proteins, including ion channels, modifying proteins, and other GPCRs, that can interact with the MCs to alter the availability of receptor at the cell surface as well as the intracellular signaling resulting from receptor activation. Different combinations of interacting proteins and MCs may therefore give rise to the complex and inconsistent functional profiles reported for the MCs. For further progress in understanding this family, improved characterization of tissue-specific functions is required. Current evidence for interactions of these receptors with a range of partners, resulting in modulation of cell signaling, suggests that each should be studied within the full context of their interacting partners. The role of physiological status in determining this context also remains to be characterized.
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Affiliation(s)
- Linda Laiho
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
| | - Joanne Fiona Murray
- Correspondence: J. F. Murray, PhD, Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, 15 George Square, Edinburgh EH8 9DX, UK.
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Chang M, Chen B, Shaffner J, Dworkin LD, Gong R. Melanocortin System in Kidney Homeostasis and Disease: Novel Therapeutic Opportunities. Front Physiol 2021; 12:651236. [PMID: 33716796 PMCID: PMC7943476 DOI: 10.3389/fphys.2021.651236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 02/03/2021] [Indexed: 12/30/2022] Open
Abstract
Melanocortin peptides, melanocortin receptors, melanocortin receptor accessory proteins, and endogenous antagonists of melanocortin receptors are the key components constituting the melanocortin hormone system, one of the most complex and important hormonal systems in our body. A plethora of evidence suggests that melanocortins possess a protective activity in a variety of kidney diseases in both rodent models and human patients. In particular, the steroidogenic melanocortin peptide adrenocorticotropic hormone (ACTH), has been shown to exert a beneficial effect in a number of kidney diseases, possibly via a mechanism independent of its steroidogenic activity. In patients with steroid-resistant nephrotic glomerulopathy, ACTH monotherapy is still effective in inducing proteinuria remission. This has inspired research on potential implications of the melanocortin system in glomerular diseases. However, our understanding of the role of the melanocortinergic pathway in kidney disease is very limited, and there are still huge unknowns to be explored. The most controversial among these is the identification of effector cells in the kidney as well as the melanocortin receptors responsible for conveying the renoprotective action. This review article introduces the melanocortin hormone system, summarizes the existing evidence for the expression of melanocortin receptors in the kidney, and evaluates the potential strategy of melanocortin therapy for kidney disease.
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Affiliation(s)
- Mingyang Chang
- Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, OH, United States
| | - Bohan Chen
- Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, OH, United States
| | - James Shaffner
- Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, OH, United States
| | - Lance D Dworkin
- Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, OH, United States
| | - Rujun Gong
- Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, OH, United States
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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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Holloway PM, Durrenberger PF, Trutschl M, Cvek U, Cooper D, Orr AW, Perretti M, Getting SJ, Gavins FNE. Both MC1 and MC3 Receptors Provide Protection From Cerebral Ischemia-Reperfusion-Induced Neutrophil Recruitment. Arterioscler Thromb Vasc Biol 2015; 35:1936-44. [PMID: 26112010 DOI: 10.1161/atvbaha.115.305348] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 06/11/2015] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Neutrophil recruitment is a key process in the pathogenesis of stroke, and may provide a valuable therapeutic target. Targeting the melanocortin (MC) receptors has previously shown to inhibit leukocyte recruitment in peripheral inflammation, however, it is not known whether treatments are effective in the unique cerebral microvascular environment. Here, we provide novel research highlighting the effects of the MC peptides on cerebral neutrophil recruitment, demonstrating important yet discrete roles for both MC1 and MC3. APPROACH AND RESULTS Using intravital microscopy, in 2 distinct murine models of cerebral ischemia-reperfusion (I/R) injury, we have investigated MC control for neutrophil recruitment. After global I/R, pharmacological treatments suppressed pathological neutrophil recruitment. MC1 selective treatment rapidly inhibited neutrophil recruitment while a nonselective MC agonist provided protection even when coadministered with an MC3/4 antagonist, suggesting the importance of early MC1 signaling. However, by 2-hour reperfusion, MC1-mediated effects were reduced, and MC3 anti-inflammatory circuits predominated. Mice bearing a nonfunctional MC1 displayed a transient exacerbation of neutrophil recruitment after global I/R, which diminished by 2 hours. However importantly, enhanced inflammatory responses in both MC1 mutant and MC3 (-/-) mice resulted in increased infarct size and poor functional outcome after focal I/R. Furthermore, we used an in vitro model of leukocyte recruitment to demonstrate these anti-inflammatory actions are also effective in human cells. CONCLUSIONS These studies reveal for the first time MC control for neutrophil recruitment in the unique pathophysiological context of cerebral I/R, while also demonstrating the potential therapeutic value of targeting multiple MCs in developing effective therapeutics.
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MESH Headings
- Animals
- Brain Ischemia/etiology
- Brain Ischemia/metabolism
- Brain Ischemia/prevention & control
- Disease Models, Animal
- Gene Expression Regulation
- Humans
- Male
- Melanocyte-Stimulating Hormones/pharmacology
- Mice
- Neutrophil Infiltration/genetics
- RNA, Messenger/genetics
- Receptor, Melanocortin, Type 1/antagonists & inhibitors
- Receptor, Melanocortin, Type 1/biosynthesis
- Receptor, Melanocortin, Type 1/genetics
- Receptor, Melanocortin, Type 3/antagonists & inhibitors
- Receptor, Melanocortin, Type 3/biosynthesis
- Receptor, Melanocortin, Type 3/genetics
- Reperfusion Injury/complications
- Reperfusion Injury/metabolism
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Affiliation(s)
- Paul M Holloway
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Pascal F Durrenberger
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Marjan Trutschl
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Urska Cvek
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Dianne Cooper
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - A Wayne Orr
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Mauro Perretti
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Stephen J Getting
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Felicity N E Gavins
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.).
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Rinne P, Penttinen AM, Nordlund W, Ahotupa M, Savontaus E. α-MSH analogue attenuates blood pressure elevation in DOCA-salt hypertensive mice. PLoS One 2013; 8:e72857. [PMID: 23977363 PMCID: PMC3745458 DOI: 10.1371/journal.pone.0072857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 07/15/2013] [Indexed: 11/18/2022] Open
Abstract
Melanocyte-stimulating hormones, α-, β- and γ-MSH, regulate important physiological functions including energy homeostasis, inflammation and sodium metabolism. Previous studies have shown that α-MSH increases sodium excretion and promotes vascular function in rodents, but it is unexplored whether these characteristics of α-MSH could translate into therapeutic benefits in the treatment of hypertension. Therefore, we first assessed the diuretic and natriuretic properties of the stable α-MSH analogue [Nle(4), D-Phe(7)]-α-MSH (NDP-α-MSH) and investigated whether it has protective effects in deoxycorticosterone acetate (DOCA)-salt hypertensive mice. Adult male C57Bl/6N mice were subjected to DOCA-salt treatment and randomized to receive intraperitoneal injections of either saline as vehicle or NDP-α-MSH (0.3 mg/kg/day for 14 days) starting 7 days after the DOCA-salt treatment. Systemic hemodynamics, serum and urine electrolytes, and oxidative stress markers were assessed in control sham-operated and DOCA-salt mice. NDP-α-MSH elicited marked diuretic and natriuretic responses that were reversible with the MC3/4 receptor antagonist SHU9119. Chronic NDP-α-MSH treatment attenuated blood pressure elevation in DOCA-salt mice without affecting the blood pressure of normotensive control animals. Owing to the enhanced sodium excretion, NDP-α-MSH-treated mice were protected from DOCA-salt-induced hypernatremia. DOCA-salt treatment mildly increased oxidative stress at the tissue level, but NDP-α-MSH had no significant effects on the oxidative stress markers. In conclusion, treatment with NDP-α-MSH increases urinary sodium excretion and protects against DOCA-salt-induced hypertension. These findings point to the potential future use of α-MSH analogues in the treatment of hypertension.
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Affiliation(s)
- Petteri Rinne
- Department of Pharmacology, Drug Development and Therapeutics, and Turku Center for Disease Modeling, University of Turku, Turku, Finland.
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