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Merritt CR, Garcia EJ, Brehm VD, Fox RG, Moeller FG, Anastasio NC, Cunningham KA. Ghrelin receptor antagonist JMV2959 blunts cocaine and oxycodone drug-seeking, but not self-administration, in male rats. Front Pharmacol 2023; 14:1268366. [PMID: 37795028 PMCID: PMC10545966 DOI: 10.3389/fphar.2023.1268366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 09/06/2023] [Indexed: 10/06/2023] Open
Abstract
The drug overdose crisis has spawned serious health consequences, including the increased incidence of substance use disorders (SUDs), conditions manifested by escalating medical and psychological impairments. While medication management is a key adjunct in SUD treatment, this crisis has crystallized the need to develop additional therapeutics to facilitate extended recovery from SUDs. The "hunger hormone" ghrelin acts by binding to the growth hormone secretagogue receptor 1α (GHS1αR) to control homeostatic and hedonic aspects of food intake and has been implicated in the mechanisms underlying SUDs. Preclinical studies indicate that GHS1αR antagonists and inverse agonists suppress reward-related signaling associated with cocaine and opioids. In the present study, we found that the GHS1αR antagonist JMV2959 was efficacious to suppress both cue-reinforced cocaine and oxycodone drug-seeking, but not cocaine or oxycodone self-administration in male Sprague-Dawley rats. These data suggest a role of the ghrelin-GHS1αR axis in mediating overlapping reward-related aspects of cocaine and oxycodone and premises the possibility that a GHS1αR antagonist may be a valuable therapeutic strategy for relapse vulnerability in SUDs.
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Affiliation(s)
- Christina R. Merritt
- Center for Addiction Sciences and Therapeutics and Department of Pharmacology and Toxicology, John Sealy School of Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Erik J. Garcia
- Center for Addiction Sciences and Therapeutics and Department of Pharmacology and Toxicology, John Sealy School of Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Victoria D. Brehm
- Center for Addiction Sciences and Therapeutics and Department of Pharmacology and Toxicology, John Sealy School of Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Robert G. Fox
- Center for Addiction Sciences and Therapeutics and Department of Pharmacology and Toxicology, John Sealy School of Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - F. Gerard Moeller
- C. Kenneth and Dianne Wright Center for Clinical and Translational Research, Departments of Psychiatry and Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, United States
| | - Noelle C. Anastasio
- Center for Addiction Sciences and Therapeutics and Department of Pharmacology and Toxicology, John Sealy School of Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Kathryn A. Cunningham
- Center for Addiction Sciences and Therapeutics and Department of Pharmacology and Toxicology, John Sealy School of Medicine, University of Texas Medical Branch, Galveston, TX, United States
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Péraldi-Roux S, Bayle M, M'Kadmi C, Damian M, Vaillé J, Fernandez G, Paula Cornejo M, Marie J, Banères JL, Ben Haj Salah K, Fehrentz JA, Cantel S, Perello M, Denoyelle S, Oiry C, Neasta J. Design and Characterization of a Triazole-Based Growth Hormone Secretagogue Receptor Modulator Inhibiting the Glucoregulatory and Feeding Actions of Ghrelin. Biochem Pharmacol 2022; 202:115114. [DOI: 10.1016/j.bcp.2022.115114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/26/2022] [Accepted: 05/26/2022] [Indexed: 11/02/2022]
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3
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Giorgioni G, Del Bello F, Quaglia W, Botticelli L, Cifani C, Micioni Di Bonaventura E, Micioni Di Bonaventura MV, Piergentili A. Advances in the Development of Nonpeptide Small Molecules Targeting Ghrelin Receptor. J Med Chem 2022; 65:3098-3118. [PMID: 35157454 PMCID: PMC8883476 DOI: 10.1021/acs.jmedchem.1c02191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ghrelin is an octanoylated peptide acting by the activation of the growth hormone secretagogue receptor, namely, GHS-R1a. The involvement of ghrelin in several physiological processes, including stimulation of food intake, gastric emptying, body energy balance, glucose homeostasis, reduction of insulin secretion, and lipogenesis validates the considerable interest in GHS-R1a as a promising target for the treatment of numerous disorders. Over the years, several GHS-R1a ligands have been identified and some of them have been extensively studied in clinical trials. The recently resolved structures of GHS-R1a bound to ghrelin or potent ligands have provided useful information for the design of new GHS-R1a drugs. This perspective is focused on the development of recent nonpeptide small molecules acting as GHS-R1a agonists, antagonists, and inverse agonists, bearing classical or new molecular scaffolds, as well as on radiolabeled GHS-R1a ligands developed for imaging. Moreover, the pharmacological effects of the most studied ligands have been discussed.
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Affiliation(s)
- Gianfabio Giorgioni
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy
| | - Fabio Del Bello
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy
| | - Wilma Quaglia
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy
| | - Luca Botticelli
- School of Pharmacy, Pharmacology Unit, University of Camerino, Via Madonna delle Carceri 9, 62032 Camerino, Italy
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, Via Madonna delle Carceri 9, 62032 Camerino, Italy
| | - E Micioni Di Bonaventura
- School of Pharmacy, Pharmacology Unit, University of Camerino, Via Madonna delle Carceri 9, 62032 Camerino, Italy
| | - M V Micioni Di Bonaventura
- School of Pharmacy, Pharmacology Unit, University of Camerino, Via Madonna delle Carceri 9, 62032 Camerino, Italy
| | - Alessandro Piergentili
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy
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Baser T, Ozdemir E, Filiz AK, Taskiran AS, Gursoy S. Ghrelin receptor agonist hexarelin attenuates antinociceptive tolerance to morphine in rats. Can J Physiol Pharmacol 2021; 99:461-467. [PMID: 32893668 DOI: 10.1139/cjpp-2020-0218] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Ghrelin, a peptide hormone released from the gastric endocrine glands, shows analgesic activity apart from its various physiological effects. Nevertheless, the effects of ghrelin receptor (GHS-R) agonists on morphine analgesia and tolerance have not yet been elucidated. The purpose of this study was to evaluate the effects of the ghrelin receptor agonist hexarelin and antagonist [d-Lys3]-GHRP-6 on morphine antinociception and tolerance in rats. A total of 104 Wistar albino male adult rats (weighing approximately 220-240 g) were used in the experiments. To induce morphine tolerance, a three-day cumulative dose regimen was used in the rats. Then, randomly selected rats were evaluated for morphine tolerance on day 4. The analgesic effects of hexarelin (0.2 mg·kg-1), [d-Lys3]-GHRP-6 (10 mg·kg-1), and morphine (5 mg·kg-1) were measured at 30-min intervals (0, 30, 60, 90, and 120 min) by tail-flick and hot-plate analgesia tests. The findings suggest that hexarelin in combination with morphine attenuates analgesic tolerance to morphine. On the other hand, ghrelin receptor antagonist [d-Lys3]-GHRP-6 has no significant analgesic activity on the morphine tolerance in analgesia tests. Furthermore, co-administration of hexarelin and morphine increases the analgesic effect. In conclusion, these data indicate that administration of GHS-R agonist hexarelin with morphine enhances the antinociception and attenuates morphine tolerance.
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Affiliation(s)
- Tayfun Baser
- Department of Physiology, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey
| | - Ercan Ozdemir
- Department of Physiology, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey
| | - Ahmet Kemal Filiz
- Department of Physiology, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey
| | - Ahmet Sevki Taskiran
- Department of Physiology, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey
| | - Sinan Gursoy
- Department of Anesthesiology and Reanimation, Sivas Cumhuriyet University School of Medicine, Sivas, Turkey
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5
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Xiao X, Bi M, Jiao Q, Chen X, Du X, Jiang H. A new understanding of GHSR1a--independent of ghrelin activation. Ageing Res Rev 2020; 64:101187. [PMID: 33007437 DOI: 10.1016/j.arr.2020.101187] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/13/2020] [Accepted: 09/21/2020] [Indexed: 12/13/2022]
Abstract
Growth hormone secretagogue receptor 1a (GHSR1a), a member of the G protein-coupled receptor (GPCR) family, is a functional receptor of ghrelin. The expression levels and activities of GHSR1a are affected by various factors. In past years, it has been found that the ghrelin-GHSR1a system can perform biological functions such as anti-inflammation, anti-apoptosis, and anti-oxidative stress. In addition to mediating the effect of ghrelin, GHSR1a also has abnormally high constitutive activity; that is, it can still transmit intracellular signals without activation of the ghrelin ligand. This constitutive activity affects brain functions, growth and development of the body; therefore, it has profound impacts on neurodegenerative diseases and some other age-related diseases. In addition, GHSR1a can also form homodimers or heterodimers with other GPCRs, affecting the release of neurotransmitters, appetite regulation, cell proliferation and insulin release. Therefore, further understanding of the constitutive activities and dimerization of GHSR1a will enable us to better clarify the characteristics of GHSR1a and provide more therapeutic targets for drug development. Here, we focus on the roles of GHSR1a in various biological functions and provide a comprehensive summary of the current research on GHSR1a to provide broader therapeutic prospects for age-related disease treatment.
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Affiliation(s)
- Xue Xiao
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Mingxia Bi
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Qian Jiao
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Xi Chen
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Xixun Du
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China.
| | - Hong Jiang
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, School of Basic Medicine, Qingdao University, Qingdao, China.
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Sales da Silva E, Ferreira PM, Castro CH, Pacheco LF, Graziani D, Pontes CNR, Bessa ADSMD, Fernandes E, Naves LM, Ribeiro LCDS, Mendonça MM, Gomes RM, Pedrino GR, Ferreira RN, Xavier CH. Brain and kidney GHS-R1a underexpression is associated with changes in renal function and hemodynamics during neurogenic hypertension. Mol Cell Endocrinol 2020; 518:110984. [PMID: 32814069 DOI: 10.1016/j.mce.2020.110984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 08/07/2020] [Accepted: 08/07/2020] [Indexed: 10/23/2022]
Abstract
Ghrelin is a peptide hormone whose effects are mediated by the growth hormone secretagogue receptor subtype 1a (GHS-R1a), mainly expressed in the brain but also in kidneys. The hypothesis herein raised is that GHS-R1a would be player in the renal contribution to the neurogenic hypertension pathophysiology. To investigate GHS-R1a role on renal function and hemodynamics, we used Wistar (WT) and spontaneously hypertensive rats (SHR). First, we assessed the effect of systemically injected vehicle, ghrelin, GHS-R1a antagonist PF04628935, ghrelin plus PF04628935 or GHS-R1a synthetic agonist MK-677 in WT and SHR rats housed in metabolic cages (24 h). Blood and urine samples were also analyzed. Then, we assessed the GHS-R1a contribution to the control of renal vasomotion and hemodynamics in WT and SHR. Finally, we assessed the GHS-R1a levels in brain areas, aorta, renal artery, renal cortex and medulla of WT and SHR rats using western blot. We found that ghrelin and MK-677 changed osmolarity parameters of SHR, in a GHS-R1a-dependent manner. GHS-R1a antagonism reduced the urinary Na+ and K+ and creatinine clearance in WT but not in SHR. Ghrelin reduced arterial pressure and increased renal artery conductance in SHR. GHS-R1a protein levels were decreased in the kidney and brain areas of SHR when compared to WT. Therefore, GHS-R1a role in the control of renal function and hemodynamics during neurogenic hypertension seem to be different, and this may be related to brain and kidney GHS-R1a downregulation.
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Affiliation(s)
- Elder Sales da Silva
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Patrícia Maria Ferreira
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Carlos Henrique Castro
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Lilian Fernanda Pacheco
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Daniel Graziani
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Carolina Nobre Ribeiro Pontes
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Amanda de Sá Martins de Bessa
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Erika Fernandes
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Lara Marques Naves
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Larissa Cristina Dos Santos Ribeiro
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Michelle Mendanha Mendonça
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Rodrigo Mello Gomes
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Gustavo Rodrigues Pedrino
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Reginaldo Nassar Ferreira
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
| | - Carlos Henrique Xavier
- Systems Neurobiology Laboratory, Department of Physiology, Institute of Biological Sciences, Room 203, Federal University of Goiás, Goiânia, GO, 74690-900, Brazil.
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7
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Cobbina E, Lee MR, Leggio L, Akhlaghi F. A Population Pharmacokinetic Analysis of PF-5190457, a Novel Ghrelin Receptor Inverse Agonist in Healthy Volunteers and in Heavy Alcohol Drinkers. Clin Pharmacokinet 2020; 60:471-484. [PMID: 33155163 DOI: 10.1007/s40262-020-00942-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND OBJECTIVES The ghrelin receptor (GHS-R1a) is a potential target for alcohol use disorders. PF-5190457 is the first inverse agonist of GHS-R1a to progress to clinical development with potential to treat alcohol use disorder. We present a population pharmacokinetic model for PF-5190457 in non-heavy (alcohol consumption status = 0) and heavy alcohol drinkers (alcohol consumption status = 1), and identify relevant factors that can influence its pharmacokinetics. METHODS Plasma concentration-time data from non-heavy (n = 35) and heavy drinkers (n = 12) were pooled for the population pharmacokinetic model development. The influence of various covariates including alcohol consumption status was evaluated. The accuracy, precision, and robustness of the model were also evaluated using bootstrapping and visual predictive checks. RESULTS A two-compartment model best described the pharmacokinetics of PF-5190457. The apparent volume of distribution of 44.5 L, apparent clearance of 72.0 L/h, apparent peripheral volume of distribution of 271 L, apparent distributional clearance of 28.7 L/h, and first-order absorption rate constant of 0.27/h were accurate and precise. The apparent volume of distribution was 3.8-fold higher (169 L) in heavy drinkers, and correlated with a lower maximum plasma concentration in heavy drinkers compared with non-heavy drinkers at the same dose; and a corresponding reduced incidence of somnolence in heavy drinkers at doses > 50 mg. CONCLUSIONS This work provides an accurate, precise, and robust two-compartment model that describes the pharmacokinetics of PF-5190457 and suggests a possible link of PF-5190457 pharmacokinetics with somnolence. TRIAL REGISTRATION ClinicalTrials.gov identifier numbers NCT01247896 and NCT02039349.
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Affiliation(s)
- Enoch Cobbina
- Clinical Pharmacokinetics Research Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Office 495 A, Avedisian Hall, 7 Greenhouse Road, Kingston, RI, 02881, USA
| | - Mary R Lee
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research and National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Bethesda, MD, USA
| | - Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research and National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Bethesda, MD, USA.,Medication Development Program, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA.,Department of Behavioral and Social Sciences, Center for Alcohol and Addiction Studies, Brown University, Providence, RI, USA
| | - Fatemeh Akhlaghi
- Clinical Pharmacokinetics Research Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Office 495 A, Avedisian Hall, 7 Greenhouse Road, Kingston, RI, 02881, USA.
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Childs MD, Luyt LG. A Decade's Progress in the Development of Molecular Imaging Agents Targeting the Growth Hormone Secretagogue Receptor. Mol Imaging 2020; 19:1536012120952623. [PMID: 33104445 PMCID: PMC8865914 DOI: 10.1177/1536012120952623] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The growth hormone secretagogue receptor 1a (GHSR), also called the ghrelin receptor, is a G protein-coupled receptor known to play an important metabolic role in the regulation of various physiological processes, including energy expenditure, growth hormone secretion, and cell proliferation. This receptor has been implicated in numerous health issues including obesity, gastrointestinal disorders, type II diabetes, and regulation of body weight in patients with Prader-Willi syndrome, and there has been growing interest in studying its mechanism of behavior to unlock further applications of GHSR-targeted therapeutics. In addition, the GHSR is expressed in various types of cancer including prostate, breast, and testicular cancers, while aberrant expression has been reported in cardiac disease. Targeted molecular imaging of the GHSR could provide insights into its role in biological processes related to these disease states. Over the past decade, imaging probes targeting this receptor have been discovered for the imaging modalities PET, SPECT, and optical imaging. High-affinity analogues of ghrelin, the endogenous ligand for the GHSR, as well as small molecule inhibitors have been developed and evaluated both in vitro and in pre-clinical models. This review provides a comprehensive overview of the molecular imaging agents targeting the GHSR reported to the end of 2019.
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Affiliation(s)
- Marina D Childs
- Department of Chemistry, University of Western Ontario, London, Ontario, Canada
| | - Leonard G Luyt
- Department of Chemistry, University of Western Ontario, London, Ontario, Canada.,Lawson Health Research Institute, London, Ontario, Canada.,Department of Oncology, University of Western Ontario, London, Ontario, Canada.,Department of Medical Imaging, University of Western Ontario, London, Ontario, Canada
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9
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Haj Salah KB, Maingot M, Blayo AL, M'Kadmi C, Damian M, Mary S, Cantel S, Neasta J, Oiry C, Péraldi-Roux S, Fernandez G, Romero GG, Perello M, Marie J, Banères JL, Fehrentz JA, Denoyelle S. Development of Nonpeptidic Inverse Agonists of the Ghrelin Receptor (GHSR) Based on the 1,2,4-Triazole Scaffold. J Med Chem 2020; 63:10796-10815. [PMID: 32882134 DOI: 10.1021/acs.jmedchem.9b02122] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
GHSR controls, among others, growth hormone and insulin secretion, adiposity, feeding, and glucose metabolism. Therefore, an inverse agonist ligand capable of selectively targeting GHSR and reducing its high constitutive activity appears to be a good candidate for the treatment of obesity-related metabolic diseases. In this context, we present a study that led to the development of several highly potent and selective inverse agonists of GHSR based on the 1,2,4-triazole scaffold. We demonstrate that, depending on the nature of the substituents on positions 3, 4, and 5, this scaffold leads to ligands that exert an intrinsic inverse agonist activity on GHSR-catalyzed G protein activation through the stabilization of a specific inactive receptor conformation. Thanks to an in vivo evaluation, we also show that one of the most promising ligands not only exerts an effect on insulin secretion in rat pancreatic islets but also affects the orexigenic effects of ghrelin in mice.
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Affiliation(s)
| | - Mathieu Maingot
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Anne-Laure Blayo
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Céline M'Kadmi
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Marjorie Damian
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Sophie Mary
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Sonia Cantel
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Jérémie Neasta
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Catherine Oiry
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Sylvie Péraldi-Roux
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Gimena Fernandez
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell, La Plata, Buenos Aires 1900, Argentina
| | - Guadalupe García Romero
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell, La Plata, Buenos Aires 1900, Argentina
| | - Mario Perello
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell, La Plata, Buenos Aires 1900, Argentina
| | - Jacky Marie
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Jean-Louis Banères
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Jean-Alain Fehrentz
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
| | - Séverine Denoyelle
- IBMM, Univ Montpellier, CNRS, ENSCM, Faculty of Pharmacy, 34000 Montpellier, France
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10
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Moose JE, Leets KA, Mate NA, Chisholm JD, Hougland JL. An overview of ghrelin O-acyltransferase inhibitors: a literature and patent review for 2010-2019. Expert Opin Ther Pat 2020; 30:581-593. [PMID: 32564644 DOI: 10.1080/13543776.2020.1776263] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION The peptide hormone ghrelin regulates physiological processes associated with energy homeostasis such as appetite, insulin signaling, glucose metabolism, and adiposity. Ghrelin has also been implicated in a growing number of neurological pathways involved in stress response and addiction behavior. For ghrelin to bind the growth hormone secretagogue receptor 1a (GHS-R1a) and activate signaling, the hormone must first be octanoylated on a specific serine side chain. This key transformation is performed by the enzyme ghrelin O-acyltransferase (GOAT), and therefore GOAT inhibitors may be useful in treating disorders related to ghrelin signaling such as diabetes, obesity, and related metabolic syndromes. AREAS COVERED This report covers ghrelin and GOAT as potential therapeutic targets and summarizes work on GOAT inhibitors through the end of 2019, highlighting recent successes with both peptidomimetics and small molecule GOAT inhibitors as potent modulators of GOAT-catalyzed ghrelin octanoylation. EXPERT OPINION A growing body of biochemical and structural knowledge regarding the ghrelin/GOAT system now enables multiple avenues for identifying and optimizing GOAT inhibitors. We are at the beginning of a new era with increased opportunities for leveraging ghrelin and GOAT in the understanding and treatment of multiple health conditions including diabetes, obesity, and addiction.
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Affiliation(s)
- Jacob E Moose
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Katelyn A Leets
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Nilamber A Mate
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - John D Chisholm
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - James L Hougland
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
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11
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Worm DJ, Els‐Heindl S, Beck‐Sickinger AG. Targeting of peptide‐binding receptors on cancer cells with peptide‐drug conjugates. Pept Sci (Hoboken) 2020. [DOI: 10.1002/pep2.24171] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Dennis J. Worm
- Faculty of Life Sciences, Institute of BiochemistryLeipzig University Leipzig Germany
| | - Sylvia Els‐Heindl
- Faculty of Life Sciences, Institute of BiochemistryLeipzig University Leipzig Germany
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12
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Abstract
The use of an acetylene (ethynyl) group in medicinal chemistry coincides with the launch of the Journal of Medicinal Chemistry in 1959. Since then, the acetylene group has been broadly exploited in drug discovery and development. As a result, it has become recognized as a privileged structural feature for targeting a wide range of therapeutic target proteins, including MAO, tyrosine kinases, BACE1, steroid receptors, mGlu5 receptors, FFA1/GPR40, and HIV-1 RT. Furthermore, a terminal alkyne functionality is frequently introduced in chemical biology probes as a click handle to identify molecular targets and to assess target engagement. This Perspective is divided into three parts encompassing: (1) the physicochemical properties of the ethynyl group, (2) the advantages and disadvantages of the ethynyl group in medicinal chemistry, and (3) the impact of the ethynyl group on chemical biology approaches.
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Affiliation(s)
- Tanaji T Talele
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, New York 11439, United States
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13
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Ghrelin Aggravates Prostate Enlargement in Rats with Testosterone-Induced Benign Prostatic Hyperplasia, Stromal Cell Proliferation, and Smooth Muscle Contraction in Human Prostate Tissues. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4748312. [PMID: 31885795 PMCID: PMC6893282 DOI: 10.1155/2019/4748312] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/01/2019] [Accepted: 10/30/2019] [Indexed: 12/15/2022]
Abstract
Epidemiologic studies revealed a context between lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH) and metabolic syndrome. However, molecular mechanisms underlying this relationship are largely unknown. Prostate enlargement and increased prostate smooth muscle tone are important factors in the pathophysiology of LUTS suggestive of BPH. In the present study, we studied effects of the metabolic hormone ghrelin on prostate enlargement in rats with experimentally induced BPH, growth of cultured stromal cells from human prostate (WPMY-1), and smooth muscle contraction of human prostate tissues. Ghrelin (20 nmol/kg daily, p.o., 2 weeks) increased prostate size in rats with testosterone-induced BPH. Microarray identified 114 ghrelin-upregulated genes (2-fold or more) in these prostates, with possible roles in growth, smooth muscle contraction, or metabolism. 12 genes were selected for further analyses. In human prostate tissues, mRNA levels of 11 of them correlated positively with ghrelin receptor (GHSR) expression, but only two with the degree of BPH. Accordingly, no correlation was evident between GHSR expression level and BPH in human prostate tissues. In WPMY-1 cells, the GHRS agonist MK0677 upregulated 11 of the selected genes. MK0677 induced proliferation of WPMY-1 cells, shown by EdU assay, colony formation, proliferation markers, flow cytometry, and viability. In myographic measurements, GHSR agonists enhanced contractions of human prostate strips. Together, ghrelin may aggravate prostate enlargement, stromal cell growth, and prostate smooth muscle contraction in BPH. Ghrelin may deteriorate urethral obstruction independently from BPH, qualifying the ghrelin system as an attractive new target to be tested for LUTS treatment in BPH.
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Abstract
PURPOSE OF REVIEW Obesity is affecting over 600 million adults worldwide and has numerous negative effects on health. Since ghrelin positively regulates food intake and body weight, targeting its signaling to induce weight loss under conditions of obesity seems promising. Thus, the present work reviews and discusses different possibilities to alter ghrelin signaling. RECENT FINDINGS Ghrelin signaling can be altered by RNA Spiegelmers, GHSR/Fc, ghrelin-O-acyltransferase inhibitors as well as antagonists, and inverse agonists of the ghrelin receptor. PF-05190457 is the first inverse agonist of the ghrelin receptor tested in humans shown to inhibit growth hormone secretion, gastric emptying, and reduce postprandial glucose levels. Effects on body weight were not examined. Although various highly promising agents targeting ghrelin signaling exist, so far, they were mostly only tested in vitro or in animal models. Further research in humans is thus needed to further assess the effects of ghrelin antagonism on body weight especially under conditions of obesity.
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Affiliation(s)
- Martha A Schalla
- Charité Center for Internal Medicine and Dermatology, Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine; Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Andreas Stengel
- Charité Center for Internal Medicine and Dermatology, Charité Center for Internal Medicine and Dermatology, Department for Psychosomatic Medicine; Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tübingen, Tübingen, Germany.
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15
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Wenthur CJ, Gautam R, Zhou B, Vendruscolo LF, Leggio L, Janda KD. Ghrelin Receptor Influence on Cocaine Reward is Not Directly Dependent on Peripheral Acyl-Ghrelin. Sci Rep 2019; 9:1841. [PMID: 30755699 PMCID: PMC6372697 DOI: 10.1038/s41598-019-38549-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 12/31/2018] [Indexed: 12/30/2022] Open
Abstract
The peptide hormone acyl-ghrelin and its receptor, GHSR1a, represent intriguing therapeutic targets due to their actions in metabolic homeostasis and reward activity. However, this pleotropic activity makes it difficult to intervene in this system without inducing unwanted effects. Thus, it is desirable to identify passive and active regulatory mechanisms that allow differentiation between functional domains. Anatomical restriction by the blood brain barrier represents one major passive regulatory mechanism. However, it is likely that the ghrelin system is subject to additional passive mechanisms that promote independent regulation of orexigenic behavior and reward processing. By applying acyl-ghrelin sequestering antibodies, it was determined that peripheral sequestration of acyl-ghrelin is sufficient to blunt weight gain, but not cocaine rewarding effects. However, both weight gain and reward-associated behaviors were shown to be blocked by direct antagonism of GHSR1a. Overall, these data indicate that GHSR1a effects on reward are independent from peripheral acyl-ghrelin binding, whereas centrally-mediated alteration of energy storage requires peripheral acyl-ghrelin binding. This demonstration of variable ligand-dependence amongst functionally-distinct GHSR1a populations is used to generate a regulatory model for functional manipulation of specific effects when attempting to therapeutically target the ghrelin system.
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Affiliation(s)
- Cody J Wenthur
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
- Department of Pharmacy, University of Wisconsin - Madison, Madison, WI, USA
| | - Ritika Gautam
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Bin Zhou
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Leandro F Vendruscolo
- Neurobiology of Addiction Section, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research and National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Bethesda, MD, USA
- Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, RI, USA
| | - Kim D Janda
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA.
- Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, and The Worm Institute for Research and Medicine (WIRM), The Scripps Research Institute, La Jolla, CA, USA.
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16
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Affiliation(s)
- Leonard G. Luyt
- Departments of Chemistry, Oncology, and Medical Imaging, University of Western Ontario, London, ON N6A 4L6, Canada
- London Regional Cancer Program, Lawson Health Research Institute, London, ON N6A 5W9, Canada
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17
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Daina A, Giuliano C, Pietra C, Wang J, Chi Y, Zou Z, Li F, Yan Z, Zhou Y, Guainazzi A, Garcia Rubio S, Zoete V. Rational Design, Synthesis, and Pharmacological Characterization of Novel Ghrelin Receptor Inverse Agonists as Potential Treatment against Obesity-Related Metabolic Diseases. J Med Chem 2018; 61:11039-11060. [DOI: 10.1021/acs.jmedchem.8b00794] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Antoine Daina
- Molecular Modeling Group, SIB Swiss Institute of Bioinformatics, CH-1015 Lausanne, Switzerland
| | - Claudio Giuliano
- Research and Preclinical Development Department, Helsinn Healthcare, CH-6912 Lugano, Switzerland
| | - Claudio Pietra
- Research and Preclinical Development Department, Helsinn Healthcare, CH-6912 Lugano, Switzerland
| | - Junbo Wang
- Department of Medicinal Chemistry, Pharmacokinetics and Metabolism, Sundia MediTech, 388 Jialilue Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China
| | - Yushi Chi
- Department of Medicinal Chemistry, Pharmacokinetics and Metabolism, Sundia MediTech, 388 Jialilue Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China
| | - Zack Zou
- Department of Medicinal Chemistry, Pharmacokinetics and Metabolism, Sundia MediTech, 388 Jialilue Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China
| | - Fugang Li
- Department of Discovery Biology, HD Biosciences, 590 Ruiqing Road Zhangjiang East Campus, Shanghai 201201, China
| | - Zhonghua Yan
- Department of Discovery Biology, HD Biosciences, 590 Ruiqing Road Zhangjiang East Campus, Shanghai 201201, China
| | - Yifan Zhou
- Department of Discovery Biology, HD Biosciences, 590 Ruiqing Road Zhangjiang East Campus, Shanghai 201201, China
| | - Angelo Guainazzi
- Research and Development Department, Helsinn Therapeutics (US), Inc., Iselin, New Jersey 08830, United-States
| | - Silvina Garcia Rubio
- Research and Development Department, Helsinn Therapeutics (US), Inc., Iselin, New Jersey 08830, United-States
| | - Vincent Zoete
- Molecular Modeling Group, SIB Swiss Institute of Bioinformatics, CH-1015 Lausanne, Switzerland
- Department of Fundamental Oncology, Lausanne University, Ludwig Institute for Cancer Research, Route de la Corniche 9A, 1066 Epalinges, Switzerland
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Camargo-Silva G, Turones LC, da Cruz KR, Gomes KP, Mendonça MM, Nunes A, de Jesus IG, Colugnati DB, Pansani AP, Pobbe RLH, Santos R, Fontes MAP, Guatimosim S, de Castro CH, Ianzer D, Ferreira RN, Xavier CH. Ghrelin potentiates cardiac reactivity to stress by modulating sympathetic control and beta-adrenergic response. Life Sci 2018; 196:84-92. [PMID: 29366747 DOI: 10.1016/j.lfs.2018.01.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/10/2018] [Accepted: 01/18/2018] [Indexed: 02/07/2023]
Abstract
Prior evidence indicates that ghrelin is involved in the integration of cardiovascular functions and behavioral responses. Ghrelin actions are mediated by the growth hormone secretagogue receptor subtype 1a (GHS-R1a), which is expressed in peripheral tissues and central areas involved in the control of cardiovascular responses to stress. AIMS In the present study, we assessed the role of ghrelin - GHS-R1a axis in the cardiovascular reactivity to acute emotional stress in rats. MAIN METHODS AND KEY FINDINGS Ghrelin potentiated the tachycardia evoked by restraint and air jet stresses, which was reverted by GHS-R1a blockade. Evaluation of the autonomic balance revealed that the sympathetic branch modulates the ghrelin-evoked positive chronotropy. In isolated hearts, the perfusion with ghrelin potentiated the contractile responses caused by stimulation of the beta-adrenergic receptor, without altering the amplitude of the responses evoked by acetylcholine. Experiments in isolated cardiomyocytes revealed that ghrelin amplified the increases in calcium transient changes evoked by isoproterenol. SIGNIFICANCE Taken together, our results indicate that the Ghrelin-GHS-R1a axis potentiates the magnitude of stress-evoked tachycardia by modulating the autonomic nervous system and peripheral mechanisms, strongly relying on the activation of cardiac calcium transient and beta-adrenergic receptors.
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Affiliation(s)
- Gabriel Camargo-Silva
- Laboratory of Cardiovascular Physiology and Therapeutics, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil
| | - Larissa Córdova Turones
- Laboratory of Cardiovascular Physiology and Therapeutics, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil
| | - Kellen Rosa da Cruz
- Laboratory of Cardiovascular Physiology and Therapeutics, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil
| | - Karina Pereira Gomes
- Integrative Laboratory of Cardiovascular and Neurological Pathophysiology, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil
| | - Michelle Mendanha Mendonça
- Laboratory of Cardiovascular Physiology and Therapeutics, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil
| | - Allancer Nunes
- Integrative Laboratory of Cardiovascular and Neurological Pathophysiology, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil
| | - Itamar Guedes de Jesus
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Diego Basile Colugnati
- Integrative Laboratory of Cardiovascular and Neurological Pathophysiology, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil
| | - Aline Priscila Pansani
- Integrative Laboratory of Cardiovascular and Neurological Pathophysiology, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil
| | - Roger Luis Henschel Pobbe
- Laboratory of Cardiovascular Physiology and Therapeutics, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil
| | - Robson Santos
- National Institute of Science and Technology Nanobiopharmaceutics (INCT NanoBioFar), Brazil
| | | | - Silvia Guatimosim
- Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil; National Institute of Science and Technology Nanobiopharmaceutics (INCT NanoBioFar), Brazil
| | - Carlos Henrique de Castro
- Integrative Laboratory of Cardiovascular and Neurological Pathophysiology, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil; National Institute of Science and Technology Nanobiopharmaceutics (INCT NanoBioFar), Brazil
| | - Danielle Ianzer
- Laboratory of Cardiovascular Physiology and Therapeutics, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil; National Institute of Science and Technology Nanobiopharmaceutics (INCT NanoBioFar), Brazil
| | - Reginaldo Nassar Ferreira
- Laboratory of Cardiovascular Physiology and Therapeutics, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil
| | - Carlos Henrique Xavier
- Laboratory of Cardiovascular Physiology and Therapeutics, Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Goiás, Goiania, GO, Brazil; National Institute of Science and Technology Nanobiopharmaceutics (INCT NanoBioFar), Brazil.
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Fernandez G, Cabral A, Andreoli MF, Labarthe A, M'Kadmi C, Ramos JG, Marie J, Fehrentz JA, Epelbaum J, Tolle V, Perello M. Evidence Supporting a Role for Constitutive Ghrelin Receptor Signaling in Fasting-Induced Hyperphagia in Male Mice. Endocrinology 2018; 159:1021-1034. [PMID: 29300858 DOI: 10.1210/en.2017-03101] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/21/2017] [Indexed: 01/22/2023]
Abstract
Ghrelin is a potent orexigenic peptide hormone that acts through the growth hormone secretagogue receptor (GHSR), a G protein-coupled receptor highly expressed in the hypothalamus. In vitro studies have shown that GHSR displays a high constitutive activity, whose physiological relevance is uncertain. As GHSR gene expression in the hypothalamus is known to increase in fasting conditions, we tested the hypothesis that constitutive GHSR activity at the hypothalamic level drives the fasting-induced hyperphagia. We found that refed wild-type (WT) mice displayed a robust hyperphagia that continued for 5 days after refeeding and changed their food intake daily pattern. Fasted WT mice showed an increase in plasma ghrelin levels, as well as in GHSR expression levels and ghrelin binding sites in the hypothalamic arcuate nucleus. When fasting-refeeding responses were evaluated in ghrelin- or GHSR-deficient mice, only the latter displayed an ∼15% smaller hyperphagia, compared with WT mice. Finally, fasting-induced hyperphagia of WT mice was significantly smaller in mice centrally treated with the GHSR inverse agonist K-(D-1-Nal)-FwLL-NH2, compared with mice treated with vehicle, whereas it was unaffected in mice centrally treated with the GHSR antagonists D-Lys3-growth hormone-releasing peptide 6 or JMV2959. Taken together, genetic models and pharmacological results support the notion that constitutive GHSR activity modulates the magnitude of the compensatory hyperphagia triggered by fasting. Thus, the hypothalamic GHSR signaling system could affect the set point of daily food intake, independently of plasma ghrelin levels, in situations of negative energy balance.
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Affiliation(s)
- Gimena Fernandez
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology (Argentine Research Council, Scientific Research Commission of the Province of Buenos Aires and National University of La Plata), La Plata, Buenos Aires, Argentina
| | - Agustina Cabral
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology (Argentine Research Council, Scientific Research Commission of the Province of Buenos Aires and National University of La Plata), La Plata, Buenos Aires, Argentina
| | - María F Andreoli
- School of Biochemistry and Biological Sciences, National University of Litoral and Institute of Environmental Health, Santa Fe, Argentina
| | - Alexandra Labarthe
- Centre de Psychiatrie et Neurosciences Unité Mixte de Recherche Scientifique_S894 INSERM Université Paris Descartes, Sorbonne Paris-Cité, Paris, France
| | - Céline M'Kadmi
- Institut des Biomolécules Max Mousseron, Unité Mixte de Recherche Scientifique 5247 Centre National de la Recherche Scientifique-Université Montpellier-École Nationale Supérieure de Chimie de Montpellier, Faculté de Pharmacie, Montpellier, France
| | - Jorge G Ramos
- School of Biochemistry and Biological Sciences, National University of Litoral and Institute of Environmental Health, Santa Fe, Argentina
| | - Jacky Marie
- Institut des Biomolécules Max Mousseron, Unité Mixte de Recherche Scientifique 5247 Centre National de la Recherche Scientifique-Université Montpellier-École Nationale Supérieure de Chimie de Montpellier, Faculté de Pharmacie, Montpellier, France
| | - Jean-Alain Fehrentz
- Institut des Biomolécules Max Mousseron, Unité Mixte de Recherche Scientifique 5247 Centre National de la Recherche Scientifique-Université Montpellier-École Nationale Supérieure de Chimie de Montpellier, Faculté de Pharmacie, Montpellier, France
| | - Jacques Epelbaum
- Centre de Psychiatrie et Neurosciences Unité Mixte de Recherche Scientifique_S894 INSERM Université Paris Descartes, Sorbonne Paris-Cité, Paris, France
- Mécanismes Adaptatifs et Evolution, Unité Mixte de Recherche Scientifique 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle France, Brunoy, France
| | - Virginie Tolle
- Centre de Psychiatrie et Neurosciences Unité Mixte de Recherche Scientifique_S894 INSERM Université Paris Descartes, Sorbonne Paris-Cité, Paris, France
| | - Mario Perello
- Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology (Argentine Research Council, Scientific Research Commission of the Province of Buenos Aires and National University of La Plata), La Plata, Buenos Aires, Argentina
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20
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Fan XT, Tian Z, Li SZ, Zhai T, Liu JL, Wang R, Zhang CS, Wang LX, Yuan JH, Zhou Y, Dong J. Ghrelin Receptor Is Required for the Effect of Nesfatin-1 on Glucose Metabolism. Front Endocrinol (Lausanne) 2018; 9:633. [PMID: 30405536 PMCID: PMC6207996 DOI: 10.3389/fendo.2018.00633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 10/05/2018] [Indexed: 12/13/2022] Open
Abstract
Studies of nesfatin-1 in glucose metabolism have become a topic of interest recently, however, the specific receptor for nesfatin-1 has not yet been identified. Some studies hinted at a connection between nesfatin-1 and the ghrelin receptor, growth hormone secretagogue receptor. Therefore, we aimed to study the role of GHSR in the glycemic effects of nesfatin-1 as well as its downstream pathways. We employed C57/BL6 mice (wild type and GHSR knockout mice) eating a normal chow diet and a high fat diet in this study, and the experimental technique included western blot, real-time PCR, immunofluorescence and ELISA. We found that in mice fed a normal chow diet (NCD), nesfatin-1 improved glucose tolerance, up-regulated AKT kinase (AKT) mRNA levels and phosphorylation and GLUT4 membrane translocation in skeletal muscle. These effects were blocked by co-injection of GHSR antagonist [D-Lys3]-GHRP-6 and were attenuated in GHSR knockout mice. In mice fed high-fat diet (HFD), nesfatin-1 not only exerted the effects observed in NCD mice, but also suppressed appetite and raised AKT levels in liver tissues that also required GHSR. Peripheral nesfatin-1 suppressed c-fos expression of GHSR immunoreactive neurons induced by fasting in hypothalamic nuclei, indicating that nesfatin-1 inhibited the activation of central GHSR. We concluded that the effects of nesfatin-1 on food intake and glucose metabolism were GHSR-dependent, and that the glycemic effect was associated with AKT and GLUT4. This study should stimulate further exploration of the nesfatin-1 receptor.
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Affiliation(s)
- Xin-Tong Fan
- Clinical Medicine Department, Medical College, Qingdao University, Qingdao, China
| | - Zhao Tian
- Clinical Medicine Department, Medical College, Qingdao University, Qingdao, China
| | - Shi-Zhen Li
- Preventive Medicine Department, School of Public Health, Qingdao University, Qingdao, China
| | - Ting Zhai
- Preventive Medicine Department, School of Public Health, Qingdao University, Qingdao, China
| | - Jun-Li Liu
- Fraser Laboratories for Diabetes Research, Department of Medicine, The Research Institute of McGill University Health Centre, Montreal, QC, Canada
| | - Rui Wang
- Special Medicine Department, Medical College, Qingdao University, Qingdao, China
| | - Cai-Shun Zhang
- Special Medicine Department, Medical College, Qingdao University, Qingdao, China
| | - Liu-Xin Wang
- Special Medicine Department, Medical College, Qingdao University, Qingdao, China
| | - Jun-Hua Yuan
- Special Medicine Department, Medical College, Qingdao University, Qingdao, China
| | - Yu Zhou
- Physiology Department, Medical College, Qingdao University, Qingdao, China
| | - Jing Dong
- Special Medicine Department, Medical College, Qingdao University, Qingdao, China
- Physiology Department, Medical College, Qingdao University, Qingdao, China
- *Correspondence: Jing Dong
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Cleverdon ER, McGovern-Gooch KR, Hougland JL. The octanoylated energy regulating hormone ghrelin: An expanded view of ghrelin's biological interactions and avenues for controlling ghrelin signaling. Mol Membr Biol 2017; 33:111-124. [PMID: 29143554 DOI: 10.1080/09687688.2017.1388930] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Ghrelin is a small peptide hormone that requires a unique post-translational modification, serine octanoylation, to bind and activate the GHS-R1a receptor. Initially demonstrated to stimulate hunger and appetite, ghrelin-dependent signaling is implicated in a variety of neurological and physiological processes influencing diseases such as diabetes, obesity, and Prader-Willi syndrome. In addition to its cognate receptor, recent studies have revealed ghrelin interacts with a range of binding partners within the bloodstream. Defining the scope of ghrelin's interactions within the body, understanding how these interactions work in concert to modulate ghrelin signaling, and developing molecular tools for controlling ghrelin signaling are essential for exploiting ghrelin for therapeutic effect. In this review, we discuss recent findings regarding the biological effects of ghrelin signaling, outline binding partners that control ghrelin trafficking and stability in circulation, and summarize the current landscape of inhibitors targeting ghrelin octanoylation.
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Affiliation(s)
| | | | - James L Hougland
- a Department of Chemistry , Syracuse University , Syracuse , NY , USA
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22
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Abstract
Ghrelin and motilin are released from gastrointestinal endocrine cells during hunger, to act through G protein-coupled receptors that have closely related amino acid sequences. The actions of ghrelin are more complex than motilin because ghrelin also exists outside the GI tract, it is processed to des-acyl ghrelin which has activity, ghrelin can exist in truncated forms and retain activity, the ghrelin receptor can have constitutive activity and is subject to biased agonism and finally additional ghrelin-like and des-acyl ghrelin receptors are proposed. Both ghrelin and motilin can stimulate gastric emptying, acting via different pathways, perhaps influenced by biased agonism at the receptors, but research is revealing additional pathways of activity. For example, it is becoming apparent that reduction of nausea may be a key therapeutic target for ghrelin receptor agonists and perhaps for compounds that modulate the constitutive activity of the ghrelin receptor. Reduction of nausea may be the mechanism through which gastroparesis symptoms are reduced. Intriguingly, a potential ability of motilin to influence nausea is also becoming apparent. Ghrelin interacts with digestive function through its effects on appetite, and ghrelin antagonists may have a place in treating Prader-Willi syndrome. Unlike motilin, ghrelin receptor agonists also have the potential to treat constipation by acting at the lumbosacral defecation centres. In conclusion, agonists of both ghrelin and motilin receptors hold potential as treatments for specific subsets of digestive system disorders.
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23
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Moldovan RP, Els-Heindl S, Worm DJ, Kniess T, Kluge M, Beck-Sickinger AG, Deuther-Conrad W, Krügel U, Brust P. Development of Fluorinated Non-Peptidic Ghrelin Receptor Ligands for Potential Use in Molecular Imaging. Int J Mol Sci 2017; 18:ijms18040768. [PMID: 28379199 PMCID: PMC5412352 DOI: 10.3390/ijms18040768] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/23/2017] [Accepted: 03/31/2017] [Indexed: 12/19/2022] Open
Abstract
The ghrelin receptor (GhrR) is a widely investigated target in several diseases. However, the current knowledge of its role and distribution in the brain is limited. Recently, the small and non-peptidic compound (S)-6-(4-bromo-2-fluorophenoxy)-3-((1-isopropylpiperidin-3-yl)methyl)-2-methylpyrido[3,2-d]pyrimidin-4(3H)-one ((S)-9) has been described as a GhrR ligand with high binding affinity. Here, we describe the synthesis of fluorinated derivatives, the in vitro evaluation of their potency as partial agonists and selectivity at GhrRs, and their physicochemical properties. These results identified compounds (S)-9, (R)-9, and (S)-16 as suitable parent molecules for 18F-labeled positron emission tomography (PET) radiotracers to enable future investigation of GhrR in the brain.
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Affiliation(s)
- Rareş-Petru Moldovan
- Helmholtz-Zentrum Dresden-Rossendorf e. V., Institute of Radiopharmaceutical Cancer Research, 04318 Leipzig, Germany.
| | - Sylvia Els-Heindl
- Institute of Biochemistry, Universität Leipzig, 04103 Leipzig, Germany.
| | - Dennis J Worm
- Institute of Biochemistry, Universität Leipzig, 04103 Leipzig, Germany.
| | - Torsten Kniess
- Helmholtz-Zentrum Dresden-Rossendorf e. V., Institute of Radiopharmaceutical Cancer Research, 04318 Leipzig, Germany.
| | - Michael Kluge
- Department of Psychiatry, Universität Leipzig, 04103 Leipzig, Germany.
| | | | - Winnie Deuther-Conrad
- Helmholtz-Zentrum Dresden-Rossendorf e. V., Institute of Radiopharmaceutical Cancer Research, 04318 Leipzig, Germany.
| | - Ute Krügel
- Rudolf Boehm Institute of Pharmacology and Toxicology, Medical Faculty, Universität Leipzig, 04107 Leipzig, Germany.
| | - Peter Brust
- Helmholtz-Zentrum Dresden-Rossendorf e. V., Institute of Radiopharmaceutical Cancer Research, 04318 Leipzig, Germany.
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Steinert RE, Feinle-Bisset C, Asarian L, Horowitz M, Beglinger C, Geary N. Ghrelin, CCK, GLP-1, and PYY(3-36): Secretory Controls and Physiological Roles in Eating and Glycemia in Health, Obesity, and After RYGB. Physiol Rev 2017; 97:411-463. [PMID: 28003328 PMCID: PMC6151490 DOI: 10.1152/physrev.00031.2014] [Citation(s) in RCA: 358] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The efficacy of Roux-en-Y gastric-bypass (RYGB) and other bariatric surgeries in the management of obesity and type 2 diabetes mellitus and novel developments in gastrointestinal (GI) endocrinology have renewed interest in the roles of GI hormones in the control of eating, meal-related glycemia, and obesity. Here we review the nutrient-sensing mechanisms that control the secretion of four of these hormones, ghrelin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide tyrosine tyrosine [PYY(3-36)], and their contributions to the controls of GI motor function, food intake, and meal-related increases in glycemia in healthy-weight and obese persons, as well as in RYGB patients. Their physiological roles as classical endocrine and as locally acting signals are discussed. Gastric emptying, the detection of specific digestive products by small intestinal enteroendocrine cells, and synergistic interactions among different GI loci all contribute to the secretion of ghrelin, CCK, GLP-1, and PYY(3-36). While CCK has been fully established as an endogenous endocrine control of eating in healthy-weight persons, the roles of all four hormones in eating in obese persons and following RYGB are uncertain. Similarly, only GLP-1 clearly contributes to the endocrine control of meal-related glycemia. It is likely that local signaling is involved in these hormones' actions, but methods to determine the physiological status of local signaling effects are lacking. Further research and fresh approaches are required to better understand ghrelin, CCK, GLP-1, and PYY(3-36) physiology; their roles in obesity and bariatric surgery; and their therapeutic potentials.
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Affiliation(s)
- Robert E Steinert
- University of Adelaide Discipline of Medicine and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia; DSM Nutritional Products, R&D Human Nutrition and Health, Basel, Switzerland; Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Department of Biomedicine and Division of Gastroenterology, University Hospital Basel, Basel, Switzerland; and Department of Psychiatry, Weill Medical College of Cornell University, New York, New York
| | - Christine Feinle-Bisset
- University of Adelaide Discipline of Medicine and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia; DSM Nutritional Products, R&D Human Nutrition and Health, Basel, Switzerland; Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Department of Biomedicine and Division of Gastroenterology, University Hospital Basel, Basel, Switzerland; and Department of Psychiatry, Weill Medical College of Cornell University, New York, New York
| | - Lori Asarian
- University of Adelaide Discipline of Medicine and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia; DSM Nutritional Products, R&D Human Nutrition and Health, Basel, Switzerland; Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Department of Biomedicine and Division of Gastroenterology, University Hospital Basel, Basel, Switzerland; and Department of Psychiatry, Weill Medical College of Cornell University, New York, New York
| | - Michael Horowitz
- University of Adelaide Discipline of Medicine and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia; DSM Nutritional Products, R&D Human Nutrition and Health, Basel, Switzerland; Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Department of Biomedicine and Division of Gastroenterology, University Hospital Basel, Basel, Switzerland; and Department of Psychiatry, Weill Medical College of Cornell University, New York, New York
| | - Christoph Beglinger
- University of Adelaide Discipline of Medicine and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia; DSM Nutritional Products, R&D Human Nutrition and Health, Basel, Switzerland; Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Department of Biomedicine and Division of Gastroenterology, University Hospital Basel, Basel, Switzerland; and Department of Psychiatry, Weill Medical College of Cornell University, New York, New York
| | - Nori Geary
- University of Adelaide Discipline of Medicine and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide, Australia; DSM Nutritional Products, R&D Human Nutrition and Health, Basel, Switzerland; Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Department of Biomedicine and Division of Gastroenterology, University Hospital Basel, Basel, Switzerland; and Department of Psychiatry, Weill Medical College of Cornell University, New York, New York
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Kong J, Chuddy J, Stock IA, Loria PM, Straub SV, Vage C, Cameron KO, Bhattacharya SK, Lapham K, McClure KF, Zhang Y, Jackson VM. Pharmacological characterization of the first in class clinical candidate PF-05190457: a selective ghrelin receptor competitive antagonist with inverse agonism that increases vagal afferent firing and glucose-dependent insulin secretion ex vivo. Br J Pharmacol 2016; 173:1452-64. [PMID: 26784385 DOI: 10.1111/bph.13439] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 01/08/2016] [Accepted: 01/08/2016] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Ghrelin increases growth hormone secretion, gastric acid secretion, gastric motility and hunger but decreases glucose-dependent insulin secretion and insulin sensitivity in humans. Antagonizing the ghrelin receptor has potential as a therapeutic approach in the treatment of obesity and type 2 diabetes. Therefore, the aim was to pharmacologically characterize the novel small-molecule antagonist PF-05190457 and assess translational pharmacology ex vivo. EXPERIMENTAL APPROACH Radioligand binding in filter and scintillation proximity assay formats were used to evaluate affinity, and europium-labelled GTP to assess functional activity. Rat vagal afferent firing and calcium imaging in dispersed islets were used as native tissues underlying food intake and insulin secretion respectively. KEY RESULTS PF-05190457 was a potent and selective inverse agonist on constitutively active ghrelin receptors and acted as a competitive antagonist of ghrelin action, with a human Kd of 3 nM requiring 4 h to achieve equilibrium. Potency of PF-05190457 was similar across different species. PF-05190457 increased intracellular calcium within dispersed islets and increased vagal afferent firing in a concentration-dependent manner with similar potency but was threefold less potent as compared with the in vitro Ki in recombinant overexpressing cells. The effect of PF-05190457 on rodent islets was comparable with glibenclamide, but glucose-dependent and additive with the insulin secretagogue glucagon-like peptide-1. CONCLUSIONS AND IMPLICATIONS Together, these data provide the pharmacological in vitro and ex vivo characterization of the first ghrelin receptor inverse agonist, which has advanced into clinical trials to evaluate the therapeutic potential of blocking ghrelin receptors in obesity and type 2 diabetes.
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Affiliation(s)
- J Kong
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - J Chuddy
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - I A Stock
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - P M Loria
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - S V Straub
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - C Vage
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - K O Cameron
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - S K Bhattacharya
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - K Lapham
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - K F McClure
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - Y Zhang
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
| | - V M Jackson
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 01239, USA
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Wang W, Tao YX. Ghrelin Receptor Mutations and Human Obesity. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 140:131-50. [PMID: 27288828 DOI: 10.1016/bs.pmbts.2016.02.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Growth hormone secretagogue receptor (GHSR) was originally identified as an orphan receptor in porcine and rat anterior pituitary membranes. In 1999, GHSR was deorphanized and shown to be a receptor for ghrelin, a peptide hormone secreted from the stomach. Therefore, GHSR is also called ghrelin receptor. In addition to regulating growth hormone secretion, ghrelin receptor regulates various physiological processes, including food intake and energy expenditure, glucose metabolism, cardiovascular functions, gastric acid secretion and motility, and immune function. Several human genetic studies conducted in populations originated from Europe, Africa, South America, and East Asia identified rare mutations and single nucleotide polymorphisms that might be associated with human obesity and short stature. Functional analyses of mutant GHSRs reveal multiple defects, including cell surface expression, ligand binding, and basal and stimulated signaling. With growing understanding in the functionality of naturally occurring GHSR mutations, potential therapeutic strategies including pharmacological chaperones and novel ligands could be used to correct the GHSR mutants.
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Affiliation(s)
- W Wang
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA
| | - Y-X Tao
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, USA.
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Abstract
The gastrointestinal tract is the major source of the related hormones ghrelin and motilin, which act on structurally similar G protein-coupled receptors. Nevertheless, selective receptor agonists are available. The primary roles of endogenous ghrelin and motilin in the digestive system are to increase appetite or hedonic eating (ghrelin) and initiate phase III of gastric migrating myoelectric complexes (motilin). Ghrelin and motilin also both inhibit nausea. In clinical trials, the motilin receptor agonist camicinal increased gastric emptying, but at lower doses reduced gastroparesis symptoms and improved appetite. Ghrelin receptor agonists have been trialled for the treatment of diabetic gastroparesis because of their ability to increase gastric emptying, but with mixed results; however, relamorelin, a ghrelin agonist, reduced nausea and vomiting in patients with this disorder. Treatment of postoperative ileus with a ghrelin receptor agonist proved unsuccessful. Centrally penetrant ghrelin receptor agonists stimulate defecation in animals and humans, although ghrelin itself does not seem to control colorectal function. Thus, the most promising uses of motilin receptor agonists are the treatment of gastroparesis or conditions with slow gastric emptying, and ghrelin receptor agonists hold potential for the reduction of nausea and vomiting, and the treatment of constipation. Therapeutic, gastrointestinal roles for receptor antagonists or inverse agonists have not been identified.
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Orally active ghrelin receptor inverse agonists and their actions on a rat obesity model. Bioorg Med Chem 2015; 23:4792-4803. [PMID: 26100441 DOI: 10.1016/j.bmc.2015.05.047] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 05/20/2015] [Accepted: 05/22/2015] [Indexed: 01/25/2023]
Abstract
A series of 2-alkylamino nicotinamide analogs was prepared as orally active ghrelin receptor (ghrelinR) inverse agonists. Starting from compound 1, oral bioavailability was improved by modifying metabolically unstable sites and reducing molecular weight. Brain-permeable compound 33 and compound 24 with low brain permeability were tested in rat models of obesity; 30 mg/kg of compound 33 suppressed weight gain. PK/PD analysis revealed that the anti-obesity effect of ghrelinR inverse agonists depends on their brain concentrations.
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