1
|
Tezenas-du-Montcel C, Tolle V. La régulation de la prise alimentaire au travers des actions antagonistes de la ghréline et du LEAP-2. CAHIERS DE NUTRITION ET DE DIÉTÉTIQUE 2023. [DOI: 10.1016/j.cnd.2022.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
|
2
|
Yang Y, Lewis MM, Huang X, Dokholyan NV, Mailman RB. Dopamine D 1 receptor-mediated β-arrestin signaling: Insight from pharmacology, biology, behavior, and neurophysiology. Int J Biochem Cell Biol 2022; 148:106235. [PMID: 35688404 PMCID: PMC10266066 DOI: 10.1016/j.biocel.2022.106235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 02/16/2022] [Accepted: 06/03/2022] [Indexed: 11/17/2022]
Abstract
The awareness of the potential importance of functional selectivity/biased signaling has led to the discovery of biased compounds as both research tools and novel drugs. A major pan-receptor focus has been to identify GPCR-selective ligands that have bias in G protein-dependent vs. β-arrestin related signaling. Although this field has exploded during the past two decades, it is only recently that highly β-arrestin biased ligands for the dopamine D1 receptor were reported. We now summarize important pharmacological, molecular, and cellular studies relevant to D1-mediated β-arrestin-related signaling. It is intriguing that many results emerged from behavioral and physiological studies implying that bias toward or against D1-mediated β-arrestin either can improve or impair functional outcomes. We discuss the importance of understanding the translatability of cell and animal models to have more precise functional targeting to harness the value of this signaling pathway.
Collapse
Affiliation(s)
- Yang Yang
- Department of Pharmacology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Translational Brain Research Center, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA.
| | - Mechelle M Lewis
- Department of Pharmacology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Department of Neurology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Translational Brain Research Center, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA
| | - Xuemei Huang
- Department of Pharmacology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Department of Neurology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Department of Humanities, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Department of Radiology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Department of Neurosurgery, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Department of Kinesiology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Translational Brain Research Center, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA
| | - Nikolay V Dokholyan
- Department of Pharmacology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA
| | - Richard B Mailman
- Department of Pharmacology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Department of Neurology, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA; Translational Brain Research Center, Penn State Milton S. Hershey Medical Center and Penn State College of Medicine, Hershey, PA 17033, USA
| |
Collapse
|
3
|
Discovery of a functionally selective ghrelin receptor (GHSR 1a) ligand for modulating brain dopamine. Proc Natl Acad Sci U S A 2022; 119:e2112397119. [PMID: 35239443 PMCID: PMC8915830 DOI: 10.1073/pnas.2112397119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The modulation of growth hormone secretagogue receptor-1a (GHSR1a) signaling is a promising strategy for treating brain conditions of metabolism, aging, and addiction. GHSR1a activation results in pleiotropic physiological outcomes through distinct and pharmacologically separable G protein– and β-arrestin (βarr)–dependent signaling pathways. Thus, pathway-selective modulation can enable improved pharmacotherapeutics that can promote therapeutic efficacy while mitigating side effects. Here, we describe the discovery of a brain-penetrant small molecule, N8279 (NCATS-SM8864), that biases GHSR1a conformations toward Gαq activation and reduces aberrant dopaminergic behavior in mice. N8279 represents a promising chemical scaffold to advance the development of better treatments for GHSR1a-related brain disorders involving the pathological dysregulation of dopamine. The growth hormone secretagogue receptor-1a (GHSR1a) is the cognate G protein–coupled receptor (GPCR) for the peptide hormone ghrelin. GHSR1a is a promising therapeutic target for a wide range of metabolic, age-related, and central nervous system (CNS)–based conditions. In addition, growing evidence supports that GHSR1a is a modulator of dopamine (DA) homeostasis and is neuroprotective within brain DA circuits. GHSR1a signaling originates from pharmacologically separable G protein– and β-arrestin (βarr)–dependent pathways, and consequently, GHSR1a-mediated physiological responses depend upon their distinctive signaling contributions. Thus, when treating disorders of disrupted DA homeostasis, a pharmacological strategy that modulates biased GHSR1a signaling may uncouple desired therapeutic outcomes from unwanted side effects. Here, we report the discovery of a small molecule GHSR1a agonist, N8279 (NCATS-SM8864), functionally selective for G protein signaling. Comprehensive pharmacological characterization reveals that N8279 elicits potent Gαq activity at the apo- and ghrelin-bound GHSR1a. Further biochemical analysis and molecular modeling demonstrate that N8279 signaling requires the extracellular domain of GHSR1a, especially extracellular loop 2. Collectively, these findings suggest that N8279 possesses an extended binding mode into the extracellular vestibule of the GHSR1a that preferentially favors Gαq signaling over alternative G proteins and βarr2-dependent cellular responses. Critically, N8279 is brain-penetrant in mice, exhibits CNS stability, and attenuates dysfunctional DA-mediated behaviors in both genetic and pharmacological mouse models of hyperdopaminergia. Our findings provide insight into the mechanisms governing GPCR functional selectivity and emphasize how biased ligand drug development can produce novel GHSR1a pharmacotherapeutics to treat pathological disruptions of brain DA homeostasis.
Collapse
|
4
|
Vohra MS, Benchoula K, Serpell CJ, Hwa WE. AgRP/NPY and POMC neurons in the arcuate nucleus and their potential role in treatment of obesity. Eur J Pharmacol 2022; 915:174611. [PMID: 34798121 DOI: 10.1016/j.ejphar.2021.174611] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 02/08/2023]
Abstract
Obesity is a major health crisis affecting over a third of the global population. This multifactorial disease is regulated via interoceptive neural circuits in the brain, whose alteration results in excessive body weight. Certain central neuronal populations in the brain are recognised as crucial nodes in energy homeostasis; in particular, the hypothalamic arcuate nucleus (ARC) region contains two peptide microcircuits that control energy balance with antagonistic functions: agouti-related peptide/neuropeptide-Y (AgRP/NPY) signals hunger and stimulates food intake; and pro-opiomelanocortin (POMC) signals satiety and reduces food intake. These neuronal peptides levels react to energy status and integrate signals from peripheral ghrelin, leptin, and insulin to regulate feeding and energy expenditure. To manage obesity comprehensively, it is crucial to understand cellular and molecular mechanisms of information processing in ARC neurons, since these regulate energy homeostasis. Importantly, a specific strategy focusing on ARC circuits needs to be devised to assist in treating obese patients and maintaining weight loss with minimal or no side effects. The aim of this review is to elucidate the recent developments in the study of AgRP-, NPY- and POMC-producing neurons, specific to their role in controlling metabolism. The impact of ghrelin, leptin, and insulin signalling via action of these neurons is also surveyed, since they also impact energy balance through this route. Lastly, we present key proteins, targeted genes, compounds, drugs, and therapies that actively work via these neurons and could potentially be used as therapeutic targets for treating obesity conditions.
Collapse
Affiliation(s)
- Muhammad Sufyan Vohra
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University Lakeside Campus, 47500, Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - Khaled Benchoula
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University Lakeside Campus, 47500, Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - Christopher J Serpell
- School of Physical Sciences, Ingram Building, University of Kent, Canterbury, Kent, CT2 7NH, United Kingdom
| | - Wong Eng Hwa
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University Lakeside Campus, 47500, Subang Jaya, Selangor Darul Ehsan, Malaysia.
| |
Collapse
|
5
|
Yang Y. Functional Selectivity of Dopamine D 1 Receptor Signaling: Retrospect and Prospect. Int J Mol Sci 2021; 22:ijms222111914. [PMID: 34769344 PMCID: PMC8584964 DOI: 10.3390/ijms222111914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/18/2021] [Accepted: 11/01/2021] [Indexed: 11/16/2022] Open
Abstract
Research progress on dopamine D1 receptors indicates that signaling no longer is limited to G protein-dependent cyclic adenosine monophosphate phosphorylation but also includes G protein-independent β-arrestin-related mitogen-activated protein kinase activation, regulation of ion channels, phospholipase C activation, and possibly more. This review summarizes recent studies revealing the complexity of D1 signaling and its clinical implications, and suggests functional selectivity as a promising strategy for drug discovery to magnify the merit of D1 signaling. Functional selectivity/biased receptor signaling has become a major research front because of its potential to improve therapeutics through precise targeting. Retrospective pharmacological review indicated that many D1 ligands have some degree of mild functional selectivity, and novel compounds with extreme bias at D1 signaling were reported recently. Behavioral and neurophysiological studies inspired new methods to investigate functional selectivity and gave insight into the biased signaling of several drugs. Results from recent clinical trials also supported D1 functional selectivity signaling as a promising strategy for discovery and development of better therapeutics.
Collapse
Affiliation(s)
- Yang Yang
- Department of Pharmacology, Penn State University College of Medicine, Hershey, PA 17033, USA
| |
Collapse
|
6
|
Peris-Sampedro F, Le May MV, Stoltenborg I, Schéle E, Dickson SL. A skeleton in the cupboard in ghrelin research: Where are the skinny dwarfs? J Neuroendocrinol 2021; 33:e13025. [PMID: 34427011 DOI: 10.1111/jne.13025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/09/2021] [Accepted: 08/05/2021] [Indexed: 12/15/2022]
Abstract
Based on studies delivering ghrelin or ghrelin receptor agonists, we have learned a great deal about the importance of the brain ghrelin signalling system for a wide range of physiological processes that include feeding behaviours, growth hormone secretion and glucose homeostasis. Because these processes can be considered as essential to life, the question arises as to why mouse models of depleted ghrelin signalling are not all skinny dwarfs with a host of behavioural and metabolic problems. Here, we provide a systematic detailed review of the phenotype of mice with deficient ghrelin signalling to help better understand the relevance and importance of the brain ghrelin signalling system, with a particular emphasis on those questions that remain unanswered.
Collapse
Affiliation(s)
- Fiona Peris-Sampedro
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Marie V Le May
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Iris Stoltenborg
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Erik Schéle
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Suzanne L Dickson
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
7
|
Yang Y, Lee SM, Imamura F, Gowda K, Amin S, Mailman RB. D1 dopamine receptors intrinsic activity and functional selectivity affect working memory in prefrontal cortex. Mol Psychiatry 2021; 26:645-655. [PMID: 30532019 PMCID: PMC9710464 DOI: 10.1038/s41380-018-0312-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/14/2018] [Accepted: 11/15/2018] [Indexed: 01/29/2023]
Abstract
Dopamine D1 agonists enhance cognition, but the role of different signaling pathways (e.g., cAMP or β-arrestin) is unclear. The current study compared 2-methyldihydrexidine and CY208,243, drugs with different degrees of both D1 intrinsic activity and functional selectivity. 2-Methyldihydrexidine is a full agonist at adenylate cyclase and a super-agonist at β-arrestin recruitment, whereas CY208,243 has relatively high intrinsic activity at adenylate cyclase, but much lower at β-arrestin recruitment. Both drugs decreased, albeit in dissimilar ways, the firing rate of neurons in prefrontal cortex sensitive to outcome-related aspects of a working memory task. 2-Methyldihydrexidine was superior to CY208,243 in prospectively enhancing similarity and retrospectively distinguishing differences between correct and error outcomes based on firing rates, enhancing the micro-network measured by oscillations of spikes and local field potentials, and improving behavioral performance. This study is the first to examine how ligand signaling bias affects both behavioral and neurophysiological endpoints in the intact animal. The data show that maximal enhancement of cognition via D1 activation occurred with a pattern of signaling that involved full unbiased intrinsic activity, or agonists with high β-arrestin activity.
Collapse
Affiliation(s)
- Yang Yang
- Department of Pharmacology, Penn State University College of Medicine, Hershey, PA, 17033, USA.
| | - Sang-Min Lee
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033
| | - Fumiaki Imamura
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033
| | - Krishne Gowda
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033
| | - Shantu Amin
- Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033
| | - Richard B. Mailman
- Department of Neurology, Penn State University College of Medicine, Hershey PA 17033.,Department of Pharmacology, Penn State University College of Medicine, Hershey PA 17033.,Correspondence to: ,
| |
Collapse
|
8
|
Vitamin C protects against chronic social isolation stress-induced weight gain and depressive-like behavior in adult male rats. Endocr Regul 2020; 54:266-274. [PMID: 33885252 DOI: 10.2478/enr-2020-0030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Objective. Considering the importance of ghrelin in stress-induced hyperphagia and a role of antioxidants in decreasing body weight, in the present study, the effect of vitamin C (VitC) on ghrelin secretion and food intake following chronic social isolation (CIS) was evaluated in rats.Methods. Thirty two male Wistar rats (200-220g) were randomly divided into: control, VitC, CIS, and CIS + VitC groups. Animals received VitC (500 mg/kg/day)/saline by gavage for 3 weeks. For 24 h cumulative and post 18-20 h fasting food intake, fasting plasma ghrelin level, and body weight were measured. Gastric histopathology was also evaluated.Results. Results showed a marked increase in fasting plasma ghrelin and food intake in stressed rats compared to controls. VitC prevented the increases in stressed rats. Histological assessment indicated a positive effect of VitC on gastric glandular cells compared to control, an effect that might partially be a reason of significant increase of plasma ghrelin levels in VitC rats. Elevated plasma ghrelin in VitC group was even higher than that one in stressed group, whereas there were no significant changes in the food intake. Assessment of the percentage of changes in body weight during 21 days showed a significant increase in stressed rats compared to controls. Vitamin C treatment prevented this increase. Stressed rats also displayed depression-like behavior as indicated by sucrose test, whereas VitC ameliorated it.Conclusions. The data of the present study indicate that VitC may overcome ghrelin-induced hyperphagia and improve the abnormal feeding and depressive behavior in CIS rats.
Collapse
|
9
|
Abizaid A, Hougland JL. Ghrelin Signaling: GOAT and GHS-R1a Take a LEAP in Complexity. Trends Endocrinol Metab 2020; 31:107-117. [PMID: 31636018 PMCID: PMC7299083 DOI: 10.1016/j.tem.2019.09.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 12/30/2022]
Abstract
Ghrelin and the growth hormone secretagogue receptor 1a (GHS-R1a) are important targets for disorders related to energy balance and metabolic regulation. Pharmacological control of ghrelin signaling is a promising avenue to address health issues involving appetite, weight gain, obesity, and related metabolic disorders, and may be an option for patients suffering from wasting conditions like cachexia. In this review, we summarize recent developments in the biochemistry of ghrelin and GHS-R1a signaling. These include unravelling the enzymatic transformations that generate active ghrelin and the discovery of multiple proteins that interact with ghrelin and GHS-R1a to regulate signaling. Furthermore, we propose that harnessing these processes will lead to highly selective treatments to address obesity, diabetes, and other metabolism-linked disorders.
Collapse
Affiliation(s)
- Alfonso Abizaid
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - James L Hougland
- Department of Chemistry, Syracuse University, Syracuse, NY, USA.
| |
Collapse
|
10
|
Toth K, Nagi K, Slosky LM, Rochelle L, Ray C, Kaur S, Shenoy SK, Caron MG, Barak LS. Encoding the β-Arrestin Trafficking Fate of Ghrelin Receptor GHSR1a: C-Tail-Independent Molecular Determinants in GPCRs. ACS Pharmacol Transl Sci 2019; 2:230-246. [PMID: 32259059 DOI: 10.1021/acsptsci.9b00018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Indexed: 12/14/2022]
Abstract
G-protein-coupled receptors (GPCRs) can bias signaling through distinct biochemical pathways that originate from G-protein/receptor and β-arrestin/receptor complexes. Receptor conformations supporting β-arrestin engagement depend on multiple receptor determinants. Using ghrelin receptor GHR1a, we demonstrate by bioluminescence resonance energy transfer and fluorescence microscopy a critical role for its second intracellular loop 2 (ICL2) domain in stabilizing β-arrestin/GHSR1a core interactions and determining receptor trafficking fate. We validate our findings in ICL2 gain- and loss-of-function experiments assessing β-arrestin and ubiquitin-dependent internalization of the CC chemokine receptor, CCR1. Like all CC and CXC subfamily chemokine receptors, CCR1 lacks a critical proline residue found in the ICL2 consensus domain of rhodopsin-family GPCRs. Our study indicates that ICL2, C-tail determinants, and the orthosteric binding pocket that regulates β-arrestin/receptor complex stability are sufficient to encode a broad repertoire of the trafficking fates observed for rhodopsin-family GPCRs, suggesting they provide the essential elements for regulating a large fraction of β-arrestin signaling bias.
Collapse
Affiliation(s)
- Krisztian Toth
- Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States.,Pharmaceutical Sciences, Campbell University, Buies Creek, North Carolina 27506, United States
| | - Karim Nagi
- Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States.,College of Medicine, Qatar University, P.O. Box 2713, Doha, Qatar
| | - Lauren M Slosky
- Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Lauren Rochelle
- Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Caroline Ray
- Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Suneet Kaur
- Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Sudha K Shenoy
- Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States.,Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Marc G Caron
- Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States.,Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States.,Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Larry S Barak
- Departments of Cell Biology, Neurobiology, and Medicine, Duke University Medical Center, Durham, North Carolina 27710, United States
| |
Collapse
|
11
|
Abstract
The organs require oxygen and other types of nutrients (amino acids, sugars, and lipids) to function, the heart consuming large amounts of fatty acids for oxidation and adenosine triphosphate (ATP) generation.
Collapse
|
12
|
Ramirez VT, van Oeffelen WEPA, Torres-Fuentes C, Chruścicka B, Druelle C, Golubeva AV, van de Wouw M, Dinan TG, Cryan JF, Schellekens H. Differential functional selectivity and downstream signaling bias of ghrelin receptor antagonists and inverse agonists. FASEB J 2018; 33:518-531. [PMID: 30020830 DOI: 10.1096/fj.201800655r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The ghrelin receptor [growth hormone secretagogue receptor (GHSR)-1a] represents a promising pharmacologic target for the treatment of metabolic disorders, including obesity and cachexia, via central appetite modulation. The GHSR-1a has a complex pharmacology, highlighted by G-protein-dependent and -independent downstream signaling pathways and high basal constitutive activity. The functional selectivity and signaling bias of many GHSR-1a-specific ligands has not been fully characterized. In this study, we investigated the pharmacologic properties of ghrelin, MK-0677, L692,585, and [d-Lys3]-growth hormone-releasing peptide-6 (Dlys), JMV2959, and [d-Arg(1),d-Phe(5),d-Trp(7, 9),Leu(11)]-substance P (SP-analog). We investigated their effect on basal GHSR-1a constitutive signaling, ligand-directed downstream GHSR-1a signaling, functional selectivity, and signaling bias. Dlys behaved as a partial antagonist with a strong bias toward GHSR-1a-β-arrestin signaling, whereas JMV2959 acted as a full unbiased GHSR-1a antagonist. Moreover, the SP-analog behaved as an inverse agonist increasing G-protein-dependent signaling, but only at high concentrations, whereas, at low concentrations, the SP-analog attenuated β-arrestin-dependent signaling. Considering the limited success in the clinical development of GHSR-1a-targeted drugs so far, these findings provide a novel insight into the pharmacologic characteristics of GHSR-1a ligands and their signaling bias, which has important implications in the design of novel, more selective GHSR-1a ligands with predictable functional outcome and selectivity for preclinical and clinical drug development.-Ramirez, V. T., van Oeffelen, W. E. P. A., Torres-Fuentes, C., Chruścicka, B., Druelle, C., Golubeva, A. V., van de Wouw, M., Dinan, T. G., Cryan, J. F., Schellekens, H. Differential functional selectivity and downstream signaling bias of ghrelin receptor antagonists and inverse agonists.
Collapse
Affiliation(s)
- Valerie T Ramirez
- Alimentary Pharmabiotic Centre (APC) Microbiome Ireland, University College Cork, Cork, Ireland
| | | | - Cristina Torres-Fuentes
- Alimentary Pharmabiotic Centre (APC) Microbiome Ireland, University College Cork, Cork, Ireland
| | - Barbara Chruścicka
- Alimentary Pharmabiotic Centre (APC) Microbiome Ireland, University College Cork, Cork, Ireland
| | - Clementine Druelle
- Alimentary Pharmabiotic Centre (APC) Microbiome Ireland, University College Cork, Cork, Ireland
| | - Anna V Golubeva
- Alimentary Pharmabiotic Centre (APC) Microbiome Ireland, University College Cork, Cork, Ireland
| | - Marcel van de Wouw
- Alimentary Pharmabiotic Centre (APC) Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Timothy G Dinan
- Alimentary Pharmabiotic Centre (APC) Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Psychiatry, University College Cork, Cork, Ireland; and
| | - John F Cryan
- Alimentary Pharmabiotic Centre (APC) Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.,Food for Health Ireland, University College Cork, Cork, Ireland
| | - Harriët Schellekens
- Alimentary Pharmabiotic Centre (APC) Microbiome Ireland, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.,Food for Health Ireland, University College Cork, Cork, Ireland
| |
Collapse
|
13
|
Morgan AH, Andrews ZB, Davies JS. Less is more: Caloric regulation of neurogenesis and adult brain function. J Neuroendocrinol 2017; 29. [PMID: 28771924 DOI: 10.1111/jne.12512] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 07/20/2017] [Accepted: 07/26/2017] [Indexed: 12/11/2022]
Abstract
Calorie intake is essential for regulating normal physiological processes and is fundamental to maintaining life. Indeed, both extremes of calorie intake result in increased morbidity and mortality. In this review, we discuss the effect of calorie intake on adult brain function, with an emphasis on the beneficial effects of mild calorie restriction. Recent findings relating to the regenerative and protective effects of the gastrointestinal hormone, ghrelin, suggest that it may underlie the beneficial effects of calorie restriction. We discuss the putative cellular mechanisms underlying the action of ghrelin and their possible role in supporting healthy brain ageing.
Collapse
Affiliation(s)
- A H Morgan
- Molecular Neurobiology, Institute of Life Science, School of Medicine, Swansea University, Swansea, UK
| | - Z B Andrews
- Department of Physiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - J S Davies
- Molecular Neurobiology, Institute of Life Science, School of Medicine, Swansea University, Swansea, UK
| |
Collapse
|
14
|
Reiter E, Ayoub MA, Pellissier LP, Landomiel F, Musnier A, Tréfier A, Gandia J, De Pascali F, Tahir S, Yvinec R, Bruneau G, Poupon A, Crépieux P. β-arrestin signalling and bias in hormone-responsive GPCRs. Mol Cell Endocrinol 2017; 449:28-41. [PMID: 28174117 DOI: 10.1016/j.mce.2017.01.052] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 01/31/2017] [Accepted: 01/31/2017] [Indexed: 12/14/2022]
Abstract
G protein-coupled receptors (GPCRs) play crucial roles in the ability of target organs to respond to hormonal cues. GPCRs' activation mechanisms have long been considered as a two-state process connecting the agonist-bound receptor to heterotrimeric G proteins. This view is now challenged as mounting evidence point to GPCRs being connected to large arrays of transduction mechanisms involving heterotrimeric G proteins as well as other players. Amongst the G protein-independent transduction mechanisms, those elicited by β-arrestins upon their recruitment to the active receptors are by far the best characterized and apply to most GPCRs. These concepts, in conjunction with remarkable advances made in the field of GPCR structural biology and biophysics, have supported the notion of ligand-selective signalling also known as pharmacological bias. Interestingly, recent reports have opened intriguing prospects to the way β-arrestins control GPCR-mediated signalling in space and time within the cells. In the present paper, we review the existing evidence linking endocrine-related GPCRs to β-arrestin recruitement, signalling, pathophysiological implications and selective activation by biased ligands and/or receptor modifications. Emerging concepts surrounding β-arrestin-mediated transduction are discussed in the light of the peculiarities of endocrine systems.
Collapse
Affiliation(s)
- Eric Reiter
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France.
| | - Mohammed Akli Ayoub
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France; LE STUDIUM(®) Loire Valley Institute for Advanced Studies, 45000, Orléans, France; Biology Department, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | | | - Flavie Landomiel
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Astrid Musnier
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Aurélie Tréfier
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Jorge Gandia
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | | | - Shifa Tahir
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Romain Yvinec
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Gilles Bruneau
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Anne Poupon
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| | - Pascale Crépieux
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
| |
Collapse
|
15
|
Labarthe A, Tolle V. [Ghrelin: a gastric hormone at the crossroad between growth and appetite regulation]. Biol Aujourdhui 2017; 210:237-257. [PMID: 28327282 DOI: 10.1051/jbio/2016027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Indexed: 06/06/2023]
Abstract
Ghrelin is a 28 amino acid peptide hormone synthesized within the gastrointestinal tract. Initially identified as the endogenous ligand of the GHS-R1a (Growth Hormone Secretagogue Receptor 1a), ghrelin is a powerful stimulator of growth hormone (GH) secretion. At the crossroad between nutrition, growth and long-term energy metabolism, ghrelin also plays a unique role as the first identified gastric hormone increasing appetite and adiposity. However, the role of the ghrelin/GHS-R system in the physiology of growth, feeding behaviour and energy homeostasis needs to be better understood. Utilization of pharmacological tools and complementary animal models with deficiency in preproghrelin, ghrelin-O-acyl-transferase (GOAT - the enzyme that acylates ghrelin -) or GHS-R in situations of chronic undernutrition or high fat diet gives a more precise overview of the role of ghrelin in the pathophysiology of eating and metabolic disorders.
Collapse
|
16
|
Alfonzo-Méndez MA, Alcántara-Hernández R, García-Sáinz JA. Novel Structural Approaches to Study GPCR Regulation. Int J Mol Sci 2016; 18:E27. [PMID: 28025563 PMCID: PMC5297662 DOI: 10.3390/ijms18010027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 12/15/2016] [Accepted: 12/21/2016] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Upon natural agonist or pharmacological stimulation, G protein-coupled receptors (GPCRs) are subjected to posttranslational modifications, such as phosphorylation and ubiquitination. These posttranslational modifications allow protein-protein interactions that turn off and/or switch receptor signaling as well as trigger receptor internalization, recycling or degradation, among other responses. Characterization of these processes is essential to unravel the function and regulation of GPCR. METHODS In silico analysis and methods such as mass spectrometry have emerged as novel powerful tools. Both approaches have allowed proteomic studies to detect not only GPCR posttranslational modifications and receptor association with other signaling macromolecules but also to assess receptor conformational dynamics after ligand (agonist/antagonist) association. RESULTS this review aims to provide insights into some of these methodologies and to highlight how their use is enhancing our comprehension of GPCR function. We present an overview using data from different laboratories (including our own), particularly focusing on free fatty acid receptor 4 (FFA4) (previously known as GPR120) and α1A- and α1D-adrenergic receptors. From our perspective, these studies contribute to the understanding of GPCR regulation and will help to design better therapeutic agents.
Collapse
Affiliation(s)
- Marco A Alfonzo-Méndez
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México 04510, Mexico.
| | - Rocío Alcántara-Hernández
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México 04510, Mexico.
| | - J Adolfo García-Sáinz
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México 04510, Mexico.
| |
Collapse
|
17
|
Hassouna R, Labarthe A, Tolle V. Hypothalamic regulation of body growth and appetite by ghrelin-derived peptides during balanced nutrition or undernutrition. Mol Cell Endocrinol 2016; 438:42-51. [PMID: 27693419 DOI: 10.1016/j.mce.2016.09.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/25/2016] [Accepted: 09/26/2016] [Indexed: 12/16/2022]
Abstract
Among the gastrointestinal hormones that regulate food intake and energy homeostasis, ghrelin plays a unique role as the first one identified to increases appetite and stimulate GH secretion. This review highlights the latest mechanism by which ghrelin modulates body growth, appetite and energy metabolism by exploring pharmacological actions of the hormone and consequences of genetic or pharmacological blockade of the ghrelin/GHS-R (Growth Hormone Secretagogue Receptor) system on physiological responses in specific nutritional situations. Within the hypothalamus, novel mechanisms of action of this hormone involve its interaction with other ghrelin-derived peptides, such as desacyl ghrelin and obestatin, which are thought to act as functional ghrelin antagonists, and possible modulation of the GHS-R with other G-protein coupled receptors. During chronic undernutrition such as anorexia nervosa, variations of ghrelin-derived peptides may be an adaptative metabolic response to maintain normal glycemic control. Interestingly, some of ghrelin's metabolic actions are thought to be relayed through modulation of GH, an anabolic and hyperglycemic agent.
Collapse
Affiliation(s)
- Rim Hassouna
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 2 ter rue d'Alésia, 75014, Paris, France; Naomi Berrie Diabetes Center, Department of Pediatrics, Columbia University Medical Center, New York, NY, 10032, USA
| | - Alexandra Labarthe
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 2 ter rue d'Alésia, 75014, Paris, France
| | - Virginie Tolle
- UMR-S 894 INSERM, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, 2 ter rue d'Alésia, 75014, Paris, France.
| |
Collapse
|
18
|
Mani BK, Osborne-Lawrence S, Vijayaraghavan P, Hepler C, Zigman JM. β1-Adrenergic receptor deficiency in ghrelin-expressing cells causes hypoglycemia in susceptible individuals. J Clin Invest 2016; 126:3467-78. [PMID: 27548523 DOI: 10.1172/jci86270] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 07/07/2016] [Indexed: 01/06/2023] Open
Abstract
Ghrelin is an orexigenic gastric peptide hormone secreted when caloric intake is limited. Ghrelin also regulates blood glucose, as emphasized by the hypoglycemia that is induced by caloric restriction in mouse models of deficient ghrelin signaling. Here, we hypothesized that activation of β1-adrenergic receptors (β1ARs) localized to ghrelin cells is required for caloric restriction-associated ghrelin release and the ensuing protective glucoregulatory response. In mice lacking the β1AR specifically in ghrelin-expressing cells, ghrelin secretion was markedly blunted, resulting in profound hypoglycemia and prevalent mortality upon severe caloric restriction. Replacement of ghrelin blocked the effects of caloric restriction in β1AR-deficient mice. We also determined that treating calorically restricted juvenile WT mice with beta blockers led to reduced plasma ghrelin and hypoglycemia, the latter of which is similar to the life-threatening, fasting-induced hypoglycemia observed in infants treated with beta blockers. These findings highlight the critical functions of ghrelin in preventing hypoglycemia and promoting survival during severe caloric restriction and the requirement for ghrelin cell-expressed β1ARs in these processes. Moreover, these results indicate a potential role for ghrelin in mediating beta blocker-associated hypoglycemia in susceptible individuals, such as young children.
Collapse
|
19
|
Smith RG. Dissociating ghrelin-dependent G protein from β-arrestin-2 signaling in transgenic rats. Sci Signal 2016; 9:fs6. [PMID: 27095592 DOI: 10.1126/scisignal.aaf7292] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The gut-derived hormone ghrelin regulates growth hormone release, appetite, metabolism, and immune function through its receptor, the growth hormone secretagogue receptor 1a (GHSR1a). In this issue of Science Signaling, Chebani et al decode GHSR1a signaling by using transgenic rats with a mutation in GHSR1a that prevents its interaction with β-arrestin. These mutant rats are more responsive to endogenous ghrelin, resulting in increased fat deposition and insulin resistance without affecting food intake.
Collapse
Affiliation(s)
- Roy G Smith
- Department of Metabolism and Aging, Scripps Research Institute-Florida, 130 Scripps Way, #3B3, Jupiter, FL 33458, USA.
| |
Collapse
|