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Janković SM, Đešević M. Advancements in neuroactive peptides in seizures. Expert Rev Neurother 2022; 22:129-143. [DOI: 10.1080/14737175.2022.2031983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Slobodan M. Janković
- - University of Kragujevac, Faculty of Medical Sciences, Kragujevac, Serbia
- University Clinical Center, Kragujevac, Serbia
| | - Miralem Đešević
- - Private Policlinic Center Eurofarm Sarajevo, Cardiology Department, Sarajevo, Bosnia and Herzegovina
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Bencze J, Pocsai K, Murnyák B, Gergely PA, Juhász B, Szilvássy Z, Hortobágyi T. The Melanin-concentrating Hormone System in Human, Rodent and Avian Brain. Open Med (Wars) 2018; 13:264-269. [PMID: 29992190 PMCID: PMC6034100 DOI: 10.1515/med-2018-0040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/06/2018] [Indexed: 12/20/2022] Open
Abstract
Melanin-concentrating hormone (MCH) is a cyclic 19 amino acid orexigenic hypothalamic peptide. MCH is located in the lateral and dorsal hypothalamus, as well as in the zona incerta. In mammals MCH increases food intake, contributes to regulation of energy balance, temperature, reproductive function, endocrine homeostasis and biological rhythms. Several studies have proved the significance of MCH in obesity, diabetes and depression. Although the peptide is well-characterized in mouse models, much less is known about its functions in avians. In birds the MCH system especially in the lateral and basal hypothalamus has important connections to the limbic system and it coordinates the vegetative and endocrine functions, as well as the emotional behaviour. Pharmacological modulation of MCH system could contribute to the therapy of eating disorders and improve agricultural efficiency regarding avians. Reviewing the current knowledge on MCH system in human, rodents and avians may stimulate a new wave of studies in the field.
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Affiliation(s)
- János Bencze
- Division of Neuropathology, Institute of Pathology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Krisztina Pocsai
- Division of Neuropathology, Institute of Pathology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Balázs Murnyák
- MTA-DE Cerebrovascular and Neurodegenerative Research Group, Debrecen, Hungary.,Division of Neuropathology, Institute of Pathology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter Attila Gergely
- Department of Forensic Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Béla Juhász
- Department of Pharmacology and Pharmacotherapy, University of Debrecen, Debrecen, Hungary
| | - Zoltán Szilvássy
- Department of Pharmacology and Pharmacotherapy, University of Debrecen, Debrecen, Hungary
| | - Tibor Hortobágyi
- Division of Neuropathology, Institute of Pathology, Faculty of Medicine, University of Debrecen, Debrecen, Nagyerdei krt. 98., H-4032, Hungary.,Department of Pathology, Faculty of Medicine, University of Szeged, Szeged, Hungary.,Department of Old Age Psychiatry, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, UK.,MTA-DE Cerebrovascular and Neurodegenerative Research Group, Debrecen, Hungary
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Deletion of Melanin Concentrating Hormone Receptor-1 disrupts overeating in the presence of food cues. Physiol Behav 2015; 152:402-7. [DOI: 10.1016/j.physbeh.2015.05.037] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 05/09/2015] [Accepted: 05/29/2015] [Indexed: 11/24/2022]
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The melanin-concentrating hormone receptors: neuronal and non-neuronal functions. INTERNATIONAL JOURNAL OF OBESITY SUPPLEMENTS 2014; 4:S31-6. [PMID: 27152164 DOI: 10.1038/ijosup.2014.9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Melanin-concentrating hormone (MCH) is a cyclic peptide highly conserved in vertebrates and was originally identified as a skin-paling factor in Teleosts. In fishes, MCH also participates in the regulation of the stress-response and feeding behaviour. Mammalian MCH is a hypothalamic neuropeptide that displays multiple functions, mostly controlling feeding behaviour and energy homeostasis. Transgenic mouse models and pharmacological studies have shown the importance of the MCH system as a potential target in the treatment of appetite disorders and obesity as well as anxiety and psychiatric diseases. Two G-protein-coupled receptors (GPCRs) binding MCH have been characterized so far. The first, named MCH-R1 and also called SLC1, was identified through reverse pharmacology strategies by several groups as a cognate receptor of MCH. This receptor is expressed at high levels in many brain areas of rodents and primates and is also expressed in peripheral organs, albeit at a lower rate. A second receptor, designated MCH-R2, exhibited 38% identity to MCH-R1 and was identified by sequence analysis of the human genome. Interestingly, although MCH-R2 orthologues were also found in fishes, dogs, ferrets and non-human primates, this MCH receptor gene appeared either lacking or non-functional in rodents and lagomorphs. Both receptors are class I GPCRs, whose main roles are to mediate the actions of peptides and neurotransmitters in the central nervous system. However, examples of action of MCH on neuronal and non-neuronal cells are emerging that illustrate novel MCH functions. In particular, the functionality of endogenously expressed MCH-R1 has been explored in human neuroblastoma cells, SK-N-SH and SH-SY5Y cells, and in non-neuronal cell types such as the ependymocytes. Indeed, we have identified mitogen-activated protein kinase (MAPK)-dependent or calcium-dependent signalling cascades that ultimately contributed to neurite outgrowth in neuroblastoma cells or to modulation of ciliary beating in ependymal cells. The putative role of MCH on cellular shaping and plasticity on one side and volume transmission on the other must be now considered.
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Conductier G, Martin AO, Risold PY, Jego S, Lavoie R, Lafont C, Mollard P, Adamantidis A, Nahon JL. Control of ventricular ciliary beating by the melanin concentrating hormone-expressing neurons of the lateral hypothalamus: a functional imaging survey. Front Endocrinol (Lausanne) 2013; 4:182. [PMID: 24324458 PMCID: PMC3839296 DOI: 10.3389/fendo.2013.00182] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 11/07/2013] [Indexed: 12/26/2022] Open
Abstract
The cyclic peptide Melanin Concentrating Hormone (MCH) is known to control a large number of brain functions in mammals such as food intake and metabolism, stress response, anxiety, sleep/wake cycle, memory, and reward. Based on neuro-anatomical and electrophysiological studies these functions were attributed to neuronal circuits expressing MCHR1, the single MCH receptor in rodents. In complement to our recently published work (1) we provided here new data regarding the action of MCH on ependymocytes in the mouse brain. First, we establish that MCHR1 mRNA is expressed in the ependymal cells of the third ventricle epithelium. Second, we demonstrated a tonic control of MCH-expressing neurons on ependymal cilia beat frequency using in vitro optogenics. Finally, we performed in vivo measurements of CSF flow using fluorescent micro-beads in wild-type and MCHR1-knockout mice. Collectively, our results demonstrated that MCH-expressing neurons modulate ciliary beating of ependymal cells at the third ventricle and could contribute to maintain cerebro-spinal fluid homeostasis.
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Affiliation(s)
- Grégory Conductier
- UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Valbonne, France
- University of Nice Sophia Antipolis, Nice, France
| | - Agnès O. Martin
- UMR5203, Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Montpellier, France
- U661, INSERM, Montpellier, France
- UMR-5203, Universités de Montpellier 1 & 2, Montpellier, France
| | - Pierre-Yves Risold
- Laboratoire d’Histologie, IFR 133, Faculté de Médecine et de Pharmacie, Besançon, France
| | - Sonia Jego
- Douglas Mental Health University Institute, Montreal, QC, Canada
| | - Raphaël Lavoie
- Douglas Mental Health University Institute, Montreal, QC, Canada
| | - Chrystel Lafont
- UMR5203, Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Montpellier, France
- U661, INSERM, Montpellier, France
- UMR-5203, Universités de Montpellier 1 & 2, Montpellier, France
| | - Patrice Mollard
- UMR5203, Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Montpellier, France
- U661, INSERM, Montpellier, France
- UMR-5203, Universités de Montpellier 1 & 2, Montpellier, France
| | | | - Jean-Louis Nahon
- UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Valbonne, France
- University of Nice Sophia Antipolis, Nice, France
- Station de Primatologie, UPS 846, Centre National de la Recherche Scientifique, Rousset sur Arc, France
- *Correspondence: Jean-Louis Nahon, UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, 660 Route des Lucioles, Sophia Antipolis, Valbonne, France e-mail:
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Klenke S, Siffert W. SNPs in genes encoding G proteins in pharmacogenetics. Pharmacogenomics 2011; 12:633-54. [DOI: 10.2217/pgs.10.203] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Heterotrimeric guanine-binding proteins (G proteins) transmit signals from the cell surface to intracellular signal cascades and are involved in various physiological and pathophysiological processes. Polymorphisms in the genes GNB3 (encoding the Gβ3 subunit), GNAS (encoding the Gαs subunit) and GNAQ (encoding the Gαq subunit) have been the primary focus of investigation. Polymorphisms in these genes could be associated with different complex phenotypes underlining that alterations in G-protein signaling can cause multiple disorders. G proteins present a point of convergence or ‘bottleneck’ between various receptors and effectors, thus making them a sensible tool for pharmacogenetic studies. The pharmacogenetic studies performed to date mostly demonstrate an association between G-protein polymorphisms and response to therapy or occurrence of adverse drug effects. Therefore, polymorphisms in genes encoding G-protein subunits may help to individualize drug treatment in various diseases with regard to both efficacy and safety.
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Affiliation(s)
| | - Winfried Siffert
- Institut für Pharmakogenetik, Universität Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany
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Eberle AN, Mild G, Zumsteg U. Cellular models for the study of the pharmacology and signaling of melanin-concentrating hormone receptors. J Recept Signal Transduct Res 2010; 30:385-402. [PMID: 21083507 DOI: 10.3109/10799893.2010.524223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cellular models for the study of the neuropeptide melanin-concentrating hormone (MCH) have become indispensable tools for pharmacological profiling and signaling analysis of MCH and its synthetic analogues. Although expression of MCH receptors is most abundant in the brain, MCH-R(1) is also found in different peripheral tissues. Therefore, not only cell lines derived from nervous tissue but also from peripheral tissues that naturally express MCH receptors have been used to study receptor signaling and regulation. For screening of novel compounds, however, heterologous expression of MCH-R(1) or MCH-R(2) genes in HEK293, Chinese hamster ovary, COS-7, or 3T3-L1 cells, or amplified MCH-R(1) expression/signaling in IRM23 cells transfected with the G(q) protein gene are the preferred tools because of more distinct pharmacological effects induced by MCH, which include inhibition of cAMP formation, stimulation of inositol triphosphate production, increase in intracellular free Ca(2+) and/or activation of mitogen-activated protein kinases. Most of the published data originate from this type of model system, whereas data based on studies with cell lines endogenously expressing MCH receptors are more limited. This review presents an update on the different cellular models currently used for the analysis of MCH receptor interaction and signaling.
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Affiliation(s)
- Alex N Eberle
- Laboratory of Endocrinology, Department of Biomedicine, University Hospital and University Children's Hospital, University of Basel, Basel, Switzerland
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Vaudry H, Nahon JL. Melanin-concentrating hormone. Editorial. Peptides 2009; 30:1965-6. [PMID: 19765628 DOI: 10.1016/j.peptides.2009.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Accepted: 09/08/2009] [Indexed: 11/19/2022]
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Audinot V, Zuana OD, Fabry N, Ouvry C, Nosjean O, Henlin JM, Fauchère JL, Boutin JA. S38151 [p-guanidinobenzoyl-[Des-Gly(10)]-MCH(7-17)] is a potent and selective antagonist at the MCH(1) receptor and has anti-feeding properties in vivo. Peptides 2009; 30:1997-2007. [PMID: 19619599 DOI: 10.1016/j.peptides.2009.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 06/21/2009] [Accepted: 07/10/2009] [Indexed: 11/19/2022]
Abstract
Structure-activity relationships studies have established the minimal sequence of melanin-concentrating hormone (MCH) that retains full agonist potency at the MCH(1), to be the dodecapeptide MCH(6-17). The alpha-amino function is not required for activity since arginine(6) can be replaced by p-guanidinobenzoyl, further improving activity. We report that the deletion of glycine in this short potent agonist (EC(50) 3.4nM) turns it into a potent and new MCH(1) antagonist (S38151, K(B) 4.3nM in the [(35)S]-GTPgammaS binding assay), which is selective versus MCH(2). A compared Ala-scan of the agonist and antagonist sequences reveals major differences in the residues that are mandatory for affinity, including arginine(11) and tyrosine(13) for the agonist and leucine(9) for the antagonist, whereas methionine(8) was necessary for both agonist and antagonist activities. A complete molecular study of the antagonist behavior is described in the present report, with a particular focus on the description of several analogues, attempting to find structure-activity relationships. Finally, S38151 antagonizes food intake when injected intra-cerebroventricularly in the rat. This is in agreement with the in vitro data and with our previous demonstration of a good correlation between in vitro and in vivo data on MCH(1) agonists.
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Affiliation(s)
- Valérie Audinot
- Pharmacologie Moléculaire et Cellulaire, Institut de Recherches Servier, Croissy-sur-Seine, France
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MacNeil DJ, Bednarek MA. MCH receptor peptide agonists and antagonists. Peptides 2009; 30:2008-13. [PMID: 19397944 DOI: 10.1016/j.peptides.2009.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 04/14/2009] [Accepted: 04/17/2009] [Indexed: 10/20/2022]
Abstract
Melanin-concentrating hormone (MCH) is an important neuropeptide hormone involved in multiple physiological processes. Peptide derivatives of MCH have been developed as tools to aid research including potent radioligands, receptor selective agonists, and potent antagonists. These tools have been used to further understand the role of MCH in physiology, primarily in rodents. However, the tools could also help elucidate the role for MCHR1 and MCHR2 in mediating MCH signaling in higher species.
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Affiliation(s)
- Douglas J MacNeil
- Department of Metabolic Disorders, Merck Research Laboratories, Rahway, NJ 07065, USA.
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Mizusawa K, Saito Y, Wang Z, Kobayashi Y, Matsuda K, Takahashi A. Molecular cloning and expression of two melanin-concentrating hormone receptors in goldfish. Peptides 2009; 30:1990-6. [PMID: 19397943 DOI: 10.1016/j.peptides.2009.04.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 04/15/2009] [Accepted: 04/17/2009] [Indexed: 02/04/2023]
Abstract
Melanin-concentrating hormone (MCH) is a neurohypophysial hormone and induces melanin aggregation in the skin in teleosts. MCH also has multiple roles in the central regulation of food intake in teleosts and mammals. MCH receptors (MCH-R) are among type I G-protein-coupled receptors. Here, we cloned two MCH receptors from goldfish, Carassius auratus. The amino acid sequence of goldfish MCH-R1 had 57-88% homology with fish MCH-R1 and 49-50% homology with mammalian MCH-R1, while the amino acid sequence of goldfish MCH-R2 had 72-92% homology with fish MCH-R2 and 32% homology with human MCH-R2. Phylogenetic analysis showed that these two MCH-Rs are orthologous to the respective mammalian MCH-Rs. The common amino acid residues for ligand binding, signal transduction, and receptor conformation were well conserved in these receptors, although some intracellular basic-amino-acid-rich domains, which have been shown to exist in human MCH-R1 and MCH-R2, were absent in goldfish MCH-R2. When stably expressed in HEK293 cells, both goldfish MCH-R1 and MCH-R2 displayed a strong, dose-dependent, transient elevation of intracellular calcium in response to salmon MCH (EC(50)=0.8nM and 31.8nM, respectively). In contrast to goldfish MCH-R2, goldfish MCH-R1 signaling is not sensitive to pertussis toxin, suggesting an exclusive Galphaq coupling of goldfish MCH-R1 in the mammalian cell-based assay. Reverse transcriptase PCR revealed that both MCH-R1 and MCH-R2 mRNA are distributed in various tissues in goldfish. The various tissues including the brain and skin express both MCH-R1 and MCH-R2. These results suggest that these functional receptors mediate multiple effects of MCH in goldfish.
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Oh KS, Ryu SY, Lee S, Seo HW, Oh BK, Kim YS, Lee BH. Melanin-concentrating hormone-1 receptor antagonism and anti-obesity effects of ethanolic extract from Morus alba leaves in diet-induced obese mice. JOURNAL OF ETHNOPHARMACOLOGY 2009; 122:216-220. [PMID: 19330910 DOI: 10.1016/j.jep.2009.01.020] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE In Korea, Morus alba leaves have been traditionally administered as natural therapeutic agent for the alleviating dropsy and diabetes. AIM OF THE STUDY The present study was performed to evaluate melanin-concentrating hormone receptor subtype 1 (MCH1) antagonism of the ethanol extract of Morus alba leaves (EMA) and its anti-obesity effect in diet-induced obese (DIO) mice. MATERIALS AND METHODS The binding affinity of EMA for the MCH1 receptor with europium-labeled MCH (Eu-MCH), the function of recombinant MCH1 receptors expressed in CHO cells, and the anti-obesity effects in DIO mice were evaluated. RESULTS MCH1 receptor binding studies showed, EMA exhibited a potent inhibitory activity with IC50 value of 2.3+/-1.0 microg/ml. EMA (10-100 microg/ml) also inhibited the intracellular calcium mobilization with the recombinant MCH1 receptors expressed in CHO cells. In an anti-obesity study with DIO mice, longterm oral administrations of EMA for 32 consecutive days produced a dose-dependent decrease in body weight and hepatic lipid accumulation. CONCLUSIONS These results suggest that chronic treatment with EMA exerts an anti-obesity effect in DIO mice, and its direct MCH1 receptor antagonism may contribute to decrease body weight.
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Affiliation(s)
- Kwang-Seok Oh
- Drug Discovery Division, Korea Research Institute of Chemical Technology, 100 Jangdong, Yuseong, Daejeon 305-343, Republic of Korea
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Cavasotto CN, Orry AJW, Murgolo NJ, Czarniecki MF, Kocsi SA, Hawes BE, O'Neill KA, Hine H, Burton MS, Voigt JH, Abagyan RA, Bayne ML, Monsma FJ. Discovery of novel chemotypes to a G-protein-coupled receptor through ligand-steered homology modeling and structure-based virtual screening. J Med Chem 2008; 51:581-8. [PMID: 18198821 DOI: 10.1021/jm070759m] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Melanin-concentrating hormone receptor 1 (MCH-R1) is a G-protein-coupled receptor (GPCR) and a target for the development of therapeutics for obesity. The structure-based development of MCH-R1 and other GPCR antagonists is hampered by the lack of an available experimentally determined atomic structure. A ligand-steered homology modeling approach has been developed (where information about existing ligands is used explicitly to shape and optimize the binding site) followed by docking-based virtual screening. Top scoring compounds identified virtually were tested experimentally in an MCH-R1 competitive binding assay, and six novel chemotypes as low micromolar affinity antagonist "hits" were identified. This success rate is more than a 10-fold improvement over random high-throughput screening, which supports our ligand-steered method. Clearly, the ligand-steered homology modeling method reduces the uncertainty of structure modeling for difficult targets like GPCRs.
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Brown SN, Chitravanshi VC, Kawabe K, Sapru HN. Microinjections of melanin concentrating hormone into the nucleus tractus solitarius of the rat elicit depressor and bradycardic responses. Neuroscience 2007; 150:796-806. [PMID: 17988799 DOI: 10.1016/j.neuroscience.2007.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 09/28/2007] [Accepted: 10/04/2007] [Indexed: 02/07/2023]
Abstract
The presence of melanin-concentrating hormone (MCH) containing processes, projecting from the lateral hypothalamus to the medial nucleus tractus solitarius (mNTS), has been reported in the rat. It was hypothesized that MCH acting within the mNTS may modulate the central regulation of cardiovascular function. This hypothesis was tested in urethane-anesthetized, artificially ventilated, adult male Wistar rats. Microinjections (100 nl) of MCH (0.25, 0.5, 0.75, and 1 mM) into the mNTS of anesthetized rats elicited decreases in mean arterial pressure (20.4+/-1.6, 50.7+/-3.3, 35.7+/-2.8 and 30.0+/-2.6 mm Hg, respectively). The decreases in heart rate in response to these concentrations of MCH were 40.0+/-8.7, 90.0+/-13.0, 48.0+/-7.3 and 48.0+/-8.0 beats/min, respectively. Maximum cardiovascular responses were elicited by a 0.5 mM concentration of MCH. Cardiovascular responses to MCH were similar in unanesthetized mid-collicular decerebrate rats. Control microinjections of normal saline (100 nl) did not elicit any cardiovascular response. Ipsilateral or bilateral vagotomy significantly attenuated MCH-induced bradycardia. Prior microinjections of PMC-3881-PI (2 mM; MCH-1 receptor antagonist) into the mNTS blocked the cardiovascular responses to microinjections of MCH. Microinjection of MCH (0.5 mM) into the mNTS decreased efferent greater splanchnic nerve activity. Direct application of MCH (0.5 mM; 4 nl) to barosensitive nucleus tractus solitarius (NTS) neurons increased their firing rate. These results indicate that: 1) MCH microinjections into the mNTS activate MCH-1 receptors and excite barosensitive NTS neurons, causing a decrease in efferent sympathetic activity and blood pressure, and 2) MCH-induced bradycardia is mediated via the activation of the vagus nerves.
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Affiliation(s)
- S N Brown
- Department of Neurological Surgery, MSB H-586, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
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Takahashi A, Kosugi T, Kobayashi Y, Yamanome T, Schiöth HB, Kawauchi H. The melanin-concentrating hormone receptor 2 (MCH-R2) mediates the effect of MCH to control body color for background adaptation in the barfin flounder. Gen Comp Endocrinol 2007; 151:210-9. [PMID: 17324419 DOI: 10.1016/j.ygcen.2007.01.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 01/12/2007] [Accepted: 01/19/2007] [Indexed: 10/23/2022]
Abstract
Melanin-concentrating hormone (MCH) is a neuropeptide generated in neurons originating in the hypothalamus, from which axons project to the entire brain and neurohypophysis in fish. MCH has both central and peripheral roles such as food intake and body color change. Here we cloned two MCH receptors (MCH-R) from the barfin flounder, Verasper moseri, Pleuronectiformes. The phylogenetic analysis shows that these are orthologues to the mammalian MCH-R1 and MCH-R2 showing 49 and 30% amino acid sequence identity to the corresponding human receptors while they have 31% amino acid sequence identify between them. Essential amino acid residues for ligand binding, signal transduction and receptor conformation, which have been shown in mammalian MCH-R, are well conserved in the flounder MCH-Rs. MCH-R1 has one intron in the extracellular N-terminal region and MCH-R2 has one intron in the DRY motif, which is a homologous position to one of the five introns of human MCH-R2. Orthologues of MCH-R1 and MCH-R2 may have appeared by gene duplication of the ancestry of MCH-Rs having at least two introns, and then MCH-R1 and MCH-R2 inherited different introns in flounder strains. We also determined their tissue distribution and functional role in rearing condition. Reverse transcription PCR revealed that the expression of MCH-R1 is confined to the brain of the barfin flounder, while transcripts of MCH-R2 were detected in the brain, pituitary, eyeball, gill, atrium, ventricle, head kidney, body kidney, spleen, intestine, inclinator, skeletal muscle testis, ovary, eyed-side skin, and non-eyed-side skin. The expression of MCH-R2 in eyed-side skin was higher in fish reared in a black tank (121 days) than in a white tank while the expression levels of MCH in the brain were significantly greater in the group reared with the white background suggesting down-regulation of this receptor gene with increased levels of MCH. The results suggest that the MCH-R2 mediates the effect of MCH to control body color for background adaptation in the eyed-side skin of the barfin flounder.
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Affiliation(s)
- Akiyoshi Takahashi
- School of Fisheries Sciences, Kitasato University, Ofunato, Iwate 022-0101, Japan.
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Cooke D, Bloom S. The obesity pipeline: current strategies in the development of anti-obesity drugs. Nat Rev Drug Discov 2006; 5:919-31. [PMID: 17080028 DOI: 10.1038/nrd2136] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This review provides a summary of currently available pharmaceutical therapies for the treatment of obesity, along with an overview of the pipeline of products currently in development, and the key mechanisms on which the major development candidates are based. In particular, the recent increase in understanding of the role of gut peptides in energy homeostasis is highlighted as a promising source of potential future obesity therapies.
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Affiliation(s)
- Dunstan Cooke
- Thiakis Limited, Imperial BioIncubator, Bessemer Building (RSM), Prince Consort Road, London SW7 2BP, UK
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Hudson S, Kiankarimi M, Rowbottom MW, Vickers TD, Wu D, Pontillo J, Ching B, Dwight W, Goodfellow VS, Schwarz D, Heise CE, Madan A, Wen J, Ban W, Wang H, Wade WS. Synthesis and structure–activity relationships of retro bis-aminopyrrolidine urea (rAPU) derived small-molecule antagonists of the melanin-concentrating hormone receptor-1 (MCH-R1). Part 2. Bioorg Med Chem Lett 2006; 16:4922-30. [PMID: 16824755 DOI: 10.1016/j.bmcl.2006.06.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 06/13/2006] [Accepted: 06/14/2006] [Indexed: 11/20/2022]
Abstract
The design, synthesis, and SAR of a series of retro bis-aminopyrrolidine ureas are described. Compounds from this series exhibited considerable binding affinity (Ki = 1 nM) and functional activity at MCH-R1, acceptable CYP2D6 inhibition, and good rat brain exposure.
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Affiliation(s)
- Sarah Hudson
- Department of Medicinal Chemistry, Neurocrine Biosciences Inc., 12790 El Camino Real, San Diego, CA 92130, USA.
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18
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Rowbottom MW, Vickers TD, Dyck B, Grey J, Tamiya J, Zhang M, Kiankarimi M, Wu D, Dwight W, Wade WS, Schwarz D, Heise CE, Madan A, Fisher A, Petroski R, Goodfellow VS. Synthesis and structure–activity relationships of retro bis-aminopyrrolidine urea (rAPU) derived small-molecule antagonists of the melanin-concentrating hormone receptor-1 (MCH-R1). Part 1. Bioorg Med Chem Lett 2006; 16:4450-7. [PMID: 16814542 DOI: 10.1016/j.bmcl.2006.06.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 06/12/2006] [Accepted: 06/12/2006] [Indexed: 10/24/2022]
Abstract
The design, synthesis, and SAR of a series of retro bis-aminopyrrolidine ureas are described. Compounds from this series exhibited potent binding affinity and functional activity at MCH-R1, and good oral bioavailability in rat.
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Affiliation(s)
- Martin W Rowbottom
- Department of Medicinal Chemistry, Neurocrine Biosciences Inc., San Diego, CA 92130, USA.
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19
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Nahon JL. The melanocortins and melanin-concentrating hormone in the central regulation of feeding behavior and energy homeostasis. C R Biol 2006; 329:623-38; discussion 653-5. [PMID: 16860280 DOI: 10.1016/j.crvi.2006.03.021] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Accepted: 03/08/2006] [Indexed: 11/16/2022]
Abstract
A number of different neuropeptides exert powerful concerted controls on feeding behavior and energy balance, most of them being produced in hypothalamic neuronal networks under stimulation by anabolic and catabolic peripheral hormones such as ghrelin and leptin, respectively. These peptide-expressing neurons interconnect extensively to integrate the multiple opposing signals that mediate changes in energy expenditure. In the present review I have summarized our current knowledge about two key peptidic systems involved in regulating appetite and energy homeostasis, the melanocortin system (alpha-MSH, agouti and Agouti-related peptides, MC receptors and mahogany protein) and the melanin-concentrating hormone system (proMCH-derived peptides and MCH receptors) that contribute to satiety and feeding-initiation, respectively, with concurrent effects on energy expenditure. I have focused particularly on recent data concerning transgenic mice and the ongoing development of MC/MCH receptor antagonists/agonists that may represent promising drugs to treat human eating disorders on both sides of the energy balance (anorexia, obesity).
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Affiliation(s)
- Jean-Louis Nahon
- Institut de pharmacologie moléculaire et cellulaire, UMR 6097, Centre national de la recherche scientifique (CNRS), 660, route des Lucioles, Sophia-Antipolis, 06560 Valbonne, France.
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20
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Kanuma K, Omodera K, Nishiguchi M, Funakoshi T, Chaki S, Nagase Y, Iida I, Yamaguchi JI, Semple G, Tran TA, Sekiguchi Y. Identification of 4-amino-2-cyclohexylaminoquinazolines as metabolically stable melanin-concentrating hormone receptor 1 antagonists. Bioorg Med Chem 2006; 14:3307-19. [PMID: 16434202 DOI: 10.1016/j.bmc.2005.12.052] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Revised: 12/20/2005] [Accepted: 12/21/2005] [Indexed: 10/25/2022]
Abstract
The optimization of the distance between two key pharmacophore features within our first hit compounds 1a and 2a led to the identification of a new class of potent non-peptidic antagonists for the MCH-R1, based around 4-amino-2-cyclohexylaminoquinazolines. In particular, ATC0065 (2c), N2-[cis-4-([2-[4-Bromo-2-(trifluoromethoxy)phenyl]ethyl]amino)cyclohexyl]-N4,N4-dimethylquinazoline-2,4-diamine dihydrochloride, bound with high affinity to the MCH-R1 (IC50 value of 16 nM) and showed good metabolic stability in liver microsomes from human and rat.
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Affiliation(s)
- Kosuke Kanuma
- Medicinal Research Laboratories, Taisho Pharmaceutical Co. Ltd, 1-403 Yoshino-cho, Kita-ku, Saitama, Saitama 331-9530, Japan
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21
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Hervieu GJ. Further insights into the neurobiology of melanin-concentrating hormone in energy and mood balances. Expert Opin Ther Targets 2006; 10:211-29. [PMID: 16548771 DOI: 10.1517/14728222.10.2.211] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Melanin-concentrating hormone (MCH) is a critical hypothalamic anabolic neuropeptide, with key central and peripheral actions on energy balance regulation. The actions of MCH are, so far, known to be transduced through two seven-transmembrane-like receptor paralogues, named MCH1R and MCH2R. MCH2R is not functional in rodents. MCH1R is an important receptor involved in mediating feeding behaviour modulation by MCH in rodents. Pharmacological antagonism at MCH1R in rodents diminishes food intake and results in significant and sustained weight loss in fat tissues, particularly in obese animals. Additionally, MCH1R antagonists have been shown to have anxiolytic and antidepressant properties. The purpose of this review is to highlight the recent numerous pieces of evidence showing that pharmacological blockade at MCH1R could be a potential treatment for obesity and its related metabolic syndrome, as well as for various psychiatric disorders.
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Affiliation(s)
- Guillaume J Hervieu
- GlaxoSmithKline R&D, Neurology Centre of Excellence for Drug Discovery, NFSP-North, HW1713 Building H17, L1-130 C06 Third Avenue, Harlow, Essex CM19 5AW, UK.
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22
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Abstract
Heterotrimeric G proteins are key players in transmembrane signaling by coupling a huge variety of receptors to channel proteins, enzymes, and other effector molecules. Multiple subforms of G proteins together with receptors, effectors, and various regulatory proteins represent the components of a highly versatile signal transduction system. G protein-mediated signaling is employed by virtually all cells in the mammalian organism and is centrally involved in diverse physiological functions such as perception of sensory information, modulation of synaptic transmission, hormone release and actions, regulation of cell contraction and migration, or cell growth and differentiation. In this review, some of the functions of heterotrimeric G proteins in defined cells and tissues are described.
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Affiliation(s)
- Nina Wettschureck
- Institute of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, D-69120 Heidelberg, Germany
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23
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Abstract
Obesity is becoming a major public health problem throughout the world. It is now the second leading cause of death in the United States and is associated with significant, potentially life-threatening co-morbidities. Significant advances in the understanding of the physiology of body weight regulation and the pathogenesis of obesity have been achieved. A better understanding of the physiology of appetite control has enabled advances in the medical and surgical treatment of obesity. Visceral or abdominal obesity is associated with an increased risk of cardiovascular disease and type 2 diabetes. Various drugs are used in the treatment of mild obesity but they are associated with adverse effects. Surgery has become an essential part of the treatment of morbid obesity, notwithstanding the potential adverse events that accompany it. An appreciation of these problems is essential to the anaesthetist and intensivist involved in the management of this group of patients.
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Affiliation(s)
- M H Cheah
- Department of Anaesthesia and Intensive Care, Selayang Hospital, Selayang, Selangor, Malaysia
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24
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Dyke HJ, Ray NC. Recent developments in the discovery of MCH-1R antagonists for the treatment of obesity – an update. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.15.10.1303] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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25
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Rowbottom MW, Vickers TD, Dyck B, Tamiya J, Zhang M, Zhao L, Grey J, Provencal D, Schwarz D, Heise CE, Mistry M, Fisher A, Dong T, Hu T, Saunders J, Goodfellow VS. Synthesis and structure–activity relationships of biarylcarboxamide bis-aminopyrrolidine urea derived small-molecule antagonists of the melanin-concentrating hormone receptor-1 (MCH-R1). Bioorg Med Chem Lett 2005; 15:3439-45. [PMID: 15950467 DOI: 10.1016/j.bmcl.2005.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2005] [Revised: 04/27/2005] [Accepted: 05/03/2005] [Indexed: 11/21/2022]
Abstract
A novel series of bis-aminopyrrolidine ureas containing either a 4-biphenylcarboxmide or 5-phenyl-2-thiophenecarboxamide group have been identified as potent and functional antagonists of the melanin-concentrating hormone receptor-1. Syntheses and SAR are described, which led to the discovery of compounds with high binding affinity (Ki = 1 nM) for the receptor. Preliminary in vitro metabolic stability data are also reported for key compounds.
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Affiliation(s)
- Martin W Rowbottom
- Department of Medicinal Chemistry, Neurocrine Biosciences Inc., 12790 El Camino Real, San Diego, CA 92130, USA.
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26
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Beauverger P, Rodriguez M, Nicolas JP, Audinot V, Lamamy V, Dromaint S, Nagel N, Macia C, Léopold O, Galizzi JP, Caignard DH, Aldana I, Monge A, Chomarat P, Boutin JA. Functional characterization of human neuropeptide Y receptor subtype five specific antagonists using a luciferase reporter gene assay. Cell Signal 2005; 17:489-96. [PMID: 15601626 DOI: 10.1016/j.cellsig.2004.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2004] [Accepted: 09/10/2004] [Indexed: 10/26/2022]
Abstract
Neuropeptide Y (NPY) has several receptors; one of them, the neuropeptide Y5 receptor (NPY5) seems involved in feeding behavior in mammals. Although this particular receptor has been extensively studied in the literature, the difficulties encountered to obtain a stable cell line expressing this recombinant receptor have impaired the development of tools necessary to establish its molecular pharmacology. We thus established a method for the functional study of new ligands. It is based upon the cotransfection in human melatonin receptor 1 (MT1)-overexpressing HEK293 cells of three plasmids encoding melanocortin receptor (MC5), neuropeptide Y5 receptor (NPY5) and a cyclic AMP response element-controlled luciferase. Once challenged with alphaMSH, the MC5 receptor activates the cyclic AMP response, through the coupling protein subunit G(s). In contrast, NPY5 agonists, through the NPY5 receptor which is negatively coupled to the same pathway, counteract the alphaMSH-mediated effect on cyclic AMP level. Using appropriate controls, this method can pinpoint compounds with antagonistic activity. Simple and straightforward, this system permits reproducible measurements of agonist or antagonist effects in the presence of neuropeptide Y, the natural agonist. This method has the advantage over already existing methods and beyond its apparent complexity, to enhance the cyclic AMP concentration at a 'physiological' level, by opposition to a forskolin-induced adenylate cyclase activation. Finally, to further validate this assay, we showed results from (1) a series of natural peptidic agonists that permitted the standardization and (2) a series of potent nonpeptidic antagonists (affinity >10(-9) M) that form a new class of active NPY5 receptor antagonists.
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Affiliation(s)
- Philippe Beauverger
- Division de Pharmacologie Moléculaire et Cellulaire, Institut de Recherches Servier, 125 Chemin de Ronde, 78 290 Croissy-sur-Seine, France
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27
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Browning A. Recent developments in the discovery of melanin-concentrating hormone antagonists: novel antiobesity agents. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.14.3.313] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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28
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Carpenter AJ, Hertzog DL. Melanin-concentrating hormone receptor antagonists as potential antiobesity agents. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.12.11.1639] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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29
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Eberle AN, Mild G, Schlumberger S, Drozdz R, Hintermann E, Zumsteg U. Expression and characterization of melanin-concentrating hormone receptors on mammalian cell lines. Peptides 2004; 25:1585-95. [PMID: 15476925 DOI: 10.1016/j.peptides.2004.06.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Accepted: 06/08/2004] [Indexed: 11/24/2022]
Abstract
The neuropeptide melanin-concentrating hormone (MCH) is expressed in central and peripheral tissues where it participates in the complex network regulating energy homeostasis as well as in other physiologically important functions. Two MCH receptor subtypes, MCH-R1 and MCH-R2, have been cloned which signal through activation of Gi/o/q proteins and hence regulate different intracellular signals, such as inhibition of cAMP formation, stimulation of IP3 production, increase in intracellular free Ca2+ and/or activation of MAP kinases. Most of the data were obtained with cell systems heterologously expressing either of the MCH receptors. Fewer reports exist on studies with cell lines which endogenously express MCH receptors. Here, we describe human and other mammalian cell lines with which MCH receptor activation can be studied under "natural" conditions and we summarize the characteristics and signaling pathways of the MCH receptors in the different cell systems.
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Affiliation(s)
- Alex N Eberle
- Laboratory of Endocrinology, Department of Research, University Hospital Basel and University Children's Hospital Basel, Klingelbergstrasse 23, CH-4031 Basel, Switzerland.
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30
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Cardinaud B, Darré-Toulemonde F, Duhault J, Boutin JA, Nahon JL. Comparative analysis of melanin-concentrating hormone structure and activity in fishes and mammals. Peptides 2004; 25:1623-32. [PMID: 15476929 DOI: 10.1016/j.peptides.2004.05.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2004] [Accepted: 05/26/2004] [Indexed: 10/26/2022]
Abstract
A comparative analysis of the structure of the melanin-concentrating hormone (MCH) precursor reveals that this sequence has been subjected to a higher selection pressure in mammals than in teleosts, suggesting that the structural constraints have not been the same throughout the vertebrate lineage. In contrast, the MCH peptide sequence has been very well conserved in all species. A sensitive and reproducible eel skin assay was developed and allowed us to define the structural features needed for a full MCH bioactivity. It was shown that the minimal structure carrying the critical residues was the same in fishes and in mammals. A pharmacological approach confirmed that MCH receptor activation decreased the cAMP levels in the fish skin, but this effect appeared to be independent from a Galphai protein. We propose that one of the intracellular signaling pathways of the MCH receptor in fish skin is the activation of one or several cellular phosphodiesterases.
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Affiliation(s)
- Bruno Cardinaud
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR 6097, 660 route des Lucioles, Sophia Antipolis, Valbonne 06560, France
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31
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Abstract
For decades, increasingly sophisticated methods have been designed to address the problem of the involvement of the brain in the physiology of energy homeostasis and the pathogenesis of obesity. A vast number of experimental observations have been made from novel genetic and physiologic approaches that allowed the identification of metabolic hormones and their relationship to key peptidergic systems in the brain. Although the central integration of afferent signals reflecting acute and chronic energy requirements is becoming clearer, the blueprint of the central regulation of energy expenditure is not known. This review offers a look at central neuronal circuitries that are implicated in metabolism regulation and strongly suggests that without a blueprint, attempts to intervene and control energy balance will remain futile.
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Affiliation(s)
- Tamas L Horvath
- Department of Obstetrics/Gynecology and Reproductive Sciences, Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut,
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32
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Vitale RM, Pedone C, De Benedetti PG, Fanelli F. Structural features of the inactive and active states of the melanin-concentrating hormone receptors: Insights from molecular simulations. Proteins 2004; 56:430-48. [PMID: 15229878 DOI: 10.1002/prot.20125] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Comparative molecular dynamics simulations of both subtypes 1 and 2 of the melanin-concentrating hormone receptor (MCHR1 and MCHR2, respectively) in their free and hormone-bound forms have been carried out. The hormone has been used in its full-length and truncated forms, as well as in 16 mutated forms. Moreover, MCHR1 has been simulated in complex with T-226296, a novel orally active and selective antagonist. The comparative analysis of an extended number of receptor configurations suggests that the differences between inactive (i.e., free and antagonist-bound) and active (i.e., agonist-bound) states of MCHRs involve the receptor portions close to the E/DRY and NPxxY motifs, with prominence to the cytosolic extensions of helices 2, 3, 6, and 7. In fact, the active forms of these receptors share the release of selected intramolecular interactions found in the inactive forms, such as that between R3.50 of the E/DRY motif and D2.40, and that between Y7.53 of the NPxxY motif and F7.60. Another feature of the active forms of both MCHRs is the approach of "helix 8" to the cytosolic extension of helix 3. These features of the active forms are concurrent with the opening of a cleft at the cytosolic end of the helix bundle. For both MCHRs, the agonist-induced chemical information transfer from the extracellular to the cytosolic domains is mediated by a cluster of aromatic amino acids in helix 6, following the ligand interaction with selected amino acids in the extracellular half of the receptor.
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MESH Headings
- Amino Acid Motifs
- Amino Acid Sequence
- Binding Sites
- Biphenyl Compounds/metabolism
- Chemical Phenomena
- Chemistry, Physical
- Computer Simulation
- Hydrogen Bonding
- Hypothalamic Hormones/chemistry
- Hypothalamic Hormones/metabolism
- Ligands
- Melanins/chemistry
- Melanins/metabolism
- Models, Chemical
- Molecular Sequence Data
- Naphthalenes/metabolism
- Peptide Fragments/chemistry
- Pituitary Hormones/chemistry
- Pituitary Hormones/metabolism
- Protein Conformation
- Protein Structure, Secondary
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Pituitary Hormone/antagonists & inhibitors
- Receptors, Pituitary Hormone/chemistry
- Receptors, Pituitary Hormone/metabolism
- Receptors, Somatostatin/chemistry
- Rhodopsin/chemistry
- Sequence Deletion
- Sequence Homology, Amino Acid
- Thermodynamics
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Affiliation(s)
- Rosa Maria Vitale
- Department of Chemistry, University of Modena and Reggio Emilia, Modena, Italy
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33
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Shearman LP, Camacho RE, Sloan Stribling D, Zhou D, Bednarek MA, Hreniuk DL, Feighner SD, Tan CP, Howard AD, Van der Ploeg LHT, MacIntyre DE, Hickey GJ, Strack AM. Chronic MCH-1 receptor modulation alters appetite, body weight and adiposity in rats. Eur J Pharmacol 2003; 475:37-47. [PMID: 12954357 DOI: 10.1016/s0014-2999(03)02146-0] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Central administration of the neuropeptide melanin-concentrating hormone (MCH) stimulates feeding in rodents. We studied the effects of intracerebroventricular (i.c.v.) administration of an MCH-1 receptor agonist (Compound A) and an MCH-1 receptor antagonist (Compound B) on feeding in satiated rats. Compound B (10 microg, i.c.v.) blocked the acute orexigenic effect of Compound A (5 microg, i.c.v.). In an experiment designed to either stimulate or inhibit MCH-1 receptor signaling over an extended period, rats received continuous i.c.v. infusions of vehicle (saline), Compound A (30 microg/day), Compound B (30 or 48 microg/day) or neuropeptide Y (24 microg/day, as positive control) via implantable infusion pumps. Continuous MCH-1 receptor activation recapitulated the obese phenotype of MCH-over-expressor mice, manifest as enhanced feeding (+23%, P<0.001), caloric efficiency and body weight gain (+38%, P<0.005) over the 14-day period relative to controls. Chronic MCH-1 receptor activation also elevated plasma insulin and leptin levels significantly. Conversely, continuous MCH-1 receptor antagonism led to sustained reductions in food intake (-16%, P<0.001), body weight gain (-35%, P<0.01), and body fat gain relative to controls, without an effect on lean mass. Antagonism of the MCH-1 receptor may be an effective approach for the treatment of obesity.
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Affiliation(s)
- Lauren P Shearman
- Department of Pharmacology, Merck Research Laboratories, PO Box 2000, Building RY80Y-150, Rahway, NJ 07065, USA.
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34
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Hervieu G. Melanin-concentrating hormone functions in the nervous system: food intake and stress. Expert Opin Ther Targets 2003; 7:495-511. [PMID: 12885269 DOI: 10.1517/14728222.7.4.495] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Melanin-concentrating hormone (MCH) is a cyclic neuropeptide, which centrally regulates food intake and stress. MCH induces food intake in rodents and, more generally, acts as an anabolic signal in energy regulation. In addition, MCH seems to be activatory on the stress axis. Two receptors for MCH in humans have very recently been characterised, namely, MCH-R1 and MCH-R2. MCH-R1 has received considerable attention, as potent and selective antagonists acting at that receptor display anxiolytic, antidepressant and/or anorectic properties. Feeding and affective disorders are both debilitating conditions that have become serious worldwide health threats. There are as yet no efficient and/or safe cures that could contain the near-pandemia phenomen of both diseases. Thus, the discovery of MCH-R1 antagonists may lead to the development of valuable drugs to treat obesity, anxiety and depressive syndromes. In addition, it opens wide avenues to probe additional functions of the peptide, both in the brain and in the peripheral nervous system.
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Affiliation(s)
- Guillaume Hervieu
- GlaxoSmithKline R&D, Drug Discovery, Neurology Centre of Excellence for Drug Discovery, New Frontiers Science Park - North, HW1713 Building H17, L1-130 C06 Third Avenue, Harlow, Essex CM19 5AW, UK.
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35
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Schlumberger SE, Saito Y, Giller T, Hintermann E, Tanner H, Jäggin V, Zumsteg U, Civelli O, Eberle AN. Different structural requirements for melanin-concentrating hormone (MCH) interacting with rat MCH-R1 (SLC-1) and mouse B16 cell MCH-R. J Recept Signal Transduct Res 2003; 23:69-81. [PMID: 12680590 DOI: 10.1081/rrs-120018761] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Melanin-concentrating hormone (MCH) is a neuropeptide occurring in all vertebrates and some invertebrates and is now known to stimulate pigment aggregation in teleost melanophores and food-intake in mammals. Whereas the two MCH receptor subtypes hitherto cloned, MCH-R1 and MCH-R2, are thought to mediate mainly the central effects of MCH, the MCH-R on pigment cells has not yet been identified, although in some studies MCH-R1 was reported to be expressed by human melanocytes and melanoma cells. Here we present data of a structure-activity study in which 12 MCH peptides were tested on rat MCH-R1 and mouse B16 melanoma cell MCH-R, by comparing receptor binding affinities and biological activities. For receptor binding analysis with HEK-293 cells expressing rat MCH-R1 (SLC-1), the radioligand was [125I]-[Tyr13]-MCH with the natural sequence. For B16 cells (F1 and G4F sublines) expressing B16 MCH-R, the analog [125I]-[D-Phe13, Tyr19]-MCH served as radioligand. The bioassay used for MCH-R1 was intracellular Ca2+ mobilization quantified with the FLIPR instrument, whereas for B16 MCH-R the signal determined was MAP kinase activation. Our data show that some of the peptides displayed a similar relative increase or decrease of potency in both cell types tested. For example, linear MCH with Ser residues at positions 7 and 16 was almost inactive whereas a slight increase in side-chain hydrophilicity at residues 4 and 8, or truncation of MCH at the N-terminus by two residues hardly changed binding affinity or bioactivity. On the other hand, salmonic MCH which also lacks the first two residues of the mammalian sequence but in addition has different residues at positions 4, 5, 9, and 18 exhibited a 5- to 10-fold lower binding activity than MCH in both cell systems. A striking difference in ligand recognition between MCH-R1 and B16 MCH-R was however observed with modifications at position 13 of MCH: whereas L-Phe13 in [Phe13, Tyr19]-MCH was well tolerated by both MCH-R1 and B16 MCH-R, change of configuration to D-Phe13 in [D-Phe13, Tyr19]-MCH or [D-Phe13]-MCH led to a complete loss of biological activity and to a 5- to 10-fold lower binding activity with MCH-R1. By contrast, the D-Phe13 residue increased the affinity of [D-Phe13, Tyr19]-MCH to B16 MCH-R about 10-fold and elicited MAP kinase activation as observed with [Phe13, Tyr19]-MCH or MCH. These data demonstrate that ligand recognition by B16 MCH-R differs from that of MCH-R1 in several respects, indicating that the B16 MCH-R represents an MCH-R subtype different from MCH-R1.
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Affiliation(s)
- Sophie E Schlumberger
- Laboratory of Endocrinology, Department of Research (ZLF), University Hospital and University Children's Hospital, Basel, Switzerland
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36
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Chapter 2. Neuropeptide receptor antagonists for CNS disorders. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2003. [DOI: 10.1016/s0065-7743(03)38003-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Maulon-Feraille L, Della Zuana O, Suply T, Rovere-Jovene C, Audinot V, Levens N, Boutin JA, Duhault J, Nahon JL. Appetite-boosting property of pro-melanin-concentrating hormone(131-165) (neuropeptide-glutamic acid-isoleucine) is associated with proteolytic resistance. J Pharmacol Exp Ther 2002; 302:766-73. [PMID: 12130742 DOI: 10.1124/jpet.302.2.766] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Melanin-concentrating hormone (MCH) is a cyclic neuropeptide, with a major role in stimulation of feeding behavior in mammals. MCH signals in the brain occur via two seven-transmembrane G protein-coupled receptors, namely MCH1 (SLC-1, MCH(1), MCH-R1, or MCH-1R) and MCH2 (SLT, MCH(2), MCH-R2, or MCH-2R). In this study, we demonstrate that the pro-MCH(131-165) peptide neuropeptide-glutamic acid-isoleucine (NEI)-MCH is more potent than MCH in stimulating feeding in the rat. Using rat MCH1-expressed human embryonic kidney 293 cells, we show that NEI-MCH exhibits 5-fold less affinity in a binding assay and 2-fold less potency in a cAMP assay than MCH. A similar 7- to 8-fold shift in potency was observed in a Ca(2+)(i) assay using rat MCH1 or human MCH2-transfected Chinese hamster ovary cell models. This demonstrates that NEI-MCH is not a better agonist than MCH at either of the MCH receptors. Then, we compared the proteolysis resistance of MCH and NEI-MCH to rat brain membrane homogenates and purified proteases. Kinetics of peptide degradation using brain extracts indicated a t(1/2) of 34.8 min for MCH and 78.5 min for NEI-MCH with a specific pattern of cleavage of MCH but not NEI-MCH by exo- and endo-proteases. Furthermore, MCH was found highly susceptible to degradation by aminopeptidase M and endopeptidase 24.11, whereas NEI-MCH was fully resistant to proteolysis by these enzymes. Therefore, our results strongly suggest that reduced susceptibility to proteases of NEI-MCH compared with MCH account for its enhanced activity in feeding behavior. NEI-MCH represents therefore the first MCH natural functional "superagonist" so far described.
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Affiliation(s)
- Laurence Maulon-Feraille
- Institut de Pharmacologie Moléculaire et Cellulaire-Centre National de la Recherche Scientifique, Unité Mixte de Recherche 6097, 660 route des Lucioles-Sophia-Antipolis, 06560 Valbonne, France
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Audinot V, Lahaye C, Suply T, Rovère-Jovène C, Rodriguez M, Nicolas JP, Beauverger P, Cardinaud B, Galizzi JP, Fauchère JL, Nahon JL, Boutin JA. SVK14 cells express an MCH binding site different from the MCH1 or MCH2 receptor. Biochem Biophys Res Commun 2002; 295:841-8. [PMID: 12127971 DOI: 10.1016/s0006-291x(02)00763-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Melanin-concentrating hormone (MCH) is a cyclic peptide, mainly involved in the regulation of skin pigmentation in teleosts and feeding behavior in mammals. The human keratinocyte SVK14 cell line has been previously shown to express binding sites for the MCH analog [125I]-[Phe13,3-iodo-Tyr19]MCH. We report here that: (1) this binding site similarly recognized [125I]-[3-iodo-Tyr13]MCH; (2) its pharmacological profile clearly differed from those observed at the two human MCH receptor subtypes, MCH1-R and MCH2-R; (3) MCH did not induce any effect on second messenger systems (including cAMP, calcium, and MAP kinase signaling pathways), and (4) no mRNAs corresponding to the MCH receptors were found. In conclusion, the binding site characterized in the SVK14 cell line is distinct from the MCH1 and MCH2 receptors and deserves therefore further investigation.
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Affiliation(s)
- Valérie Audinot
- Division de Pharmacologie Moléculaire et Cellulaire, Institut de Recherches Servier, 125, Chemin de Ronde, Croissy-sur-Seine, France
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Schlumberger SE, Talke-Messerer C, Zumsteg U, Eberle AN. Expression of receptors for melanin-concentrating hormone (MCH) in different tissues and cell lines. J Recept Signal Transduct Res 2002; 22:509-31. [PMID: 12503638 DOI: 10.1081/rrs-120014618] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Melanin-concentrating hormone (MCH) is a potent orexigenic neuropeptide and a physiological antagonist of alpha-melanocyte-stimulating hormone (alpha-MSH) in the brain as well as at peripheral sites, including the pigmentary systems of specific vertebrates. Two receptor subtypes for MCH, MCH-R1 and MCH-R2, have been cloned, but other receptor subtypes are likely to exist. Based on our own data and the current literature, we have compared the expression of different receptors for MCH in various mammalian cell lines and tissues. Summarizing all data currently available, we conclude that the two cloned MCH receptors, MCH-R1 and MCH-R2, exhibit differences in their expression pattern, although MCH-R1 is generally colocalized in all tissues where MCH-R2 expression is found. It appears that MCH-R1 is more abundant and has a wider distribution pattern than MCH-R2. Other hypothetical MCH-R subtypes may be expressed in specific tissues, e.g., in the pigment cell system.
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Affiliation(s)
- Sophie E Schlumberger
- Laboratory of Endocrinology, Department of Research (ZLF) University Hospital and University Children's Hospital, CH-4031 Basel, Switzerland
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Chapter II The melanin-concentrating hormone. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0924-8196(02)80004-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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