1
|
Gaffey RH, Takyi AK, Shukla A. Investigational and emerging gastric inhibitory polypeptide (GIP) receptor-based therapies for the treatment of obesity. Expert Opin Investig Drugs 2024; 33:757-773. [PMID: 38984950 DOI: 10.1080/13543784.2024.2377319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 07/03/2024] [Indexed: 07/11/2024]
Abstract
INTRODUCTION One billion people live with obesity. The most promising medications for its treatment are incretin-based therapies, based on enteroendocrine peptides released in response to oral nutrients, specifically glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). The mechanisms by which GLP-1 receptor agonism cause weight reduction are becoming increasingly understood. However, the mechanisms by which GIP receptor-modulating medications cause weight loss remain to be clarified. AREAS COVERED This review describes GLP-1 and GIP physiology and explores the conflicting data regarding GIP and weight management. It details examples of how to reconcile the contradictory findings that both GIP receptor agonism and antagonism cause weight reduction. Specifically, it discusses the concept of 'biased agonism' wherein exogenous peptides cause different post-receptor signaling patterns than native ligands. It discusses how GIP effects in adipose tissue and the central nervous system may cause weight reduction. It describes GIP receptor-modulating compounds and their most current trials regarding weight reduction. EXPERT OPINION Effects of GIP receptor-modulating compounds on different tissues have implications for both weight reduction and other cardiometabolic diseases. Further study is needed to understand the implications of GIP agonism on not just weight reduction, but also cardiovascular disease, liver disease, bone health and fat storage.
Collapse
Affiliation(s)
- Robert H Gaffey
- Comprehensive Weight Control Center, Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Afua K Takyi
- Comprehensive Weight Control Center, Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Alpana Shukla
- Comprehensive Weight Control Center, Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| |
Collapse
|
2
|
Bailey CJ, Flatt PR. Duodenal enteroendocrine cells and GIP as treatment targets for obesity and type 2 diabetes. Peptides 2024; 174:171168. [PMID: 38320643 DOI: 10.1016/j.peptides.2024.171168] [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: 12/16/2023] [Revised: 02/02/2024] [Accepted: 02/02/2024] [Indexed: 02/08/2024]
Abstract
The duodenum is an important source of endocrine and paracrine signals controlling digestion and nutrient disposition, notably including the main incretin hormone glucose-dependent insulinotropic polypeptide (GIP). Bariatric procedures that prevent nutrients from contact with the duodenal mucosa are particularly effective interventions to reduce body weight and improve glycaemic control in obesity and type 2 diabetes. These procedures take advantage of increased nutrient delivery to more distal regions of the intestine which enhances secretion of the other incretin hormone glucagon-like peptide-1 (GLP-1). Preclinical experiments have shown that either an increase or a decrease in the secretion or action of GIP can decrease body weight and blood glucose in obesity and non-insulin dependent hyperglycaemia, but clinical studies involving administration of GIP have been inconclusive. However, a synthetic dual agonist peptide (tirzepatide) that exerts agonism at receptors for GIP and GLP-1 has produced marked weight-lowering and glucose-lowering effects in people with obesity and type 2 diabetes. This appears to result from chronic biased agonism in which the novel conformation of the peptide triggers enhanced signalling by the GLP-1 receptor through reduced internalisation while reducing signalling by the GIP receptor directly or via functional antagonism through increased internalisation and degradation.
Collapse
Affiliation(s)
| | - Peter R Flatt
- Diabetes Research Centre, School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine BT52 1SA Northern Ireland, UK
| |
Collapse
|
3
|
Brodosi L, Petroni ML, Marchesini G. Looking ahead to potential incretin combination therapies for non-alcoholic steatohepatitis in patients with diabetes. Expert Opin Pharmacother 2023; 24:989-1000. [PMID: 37114459 DOI: 10.1080/14656566.2023.2208746] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
INTRODUCTION There are no drugs approved by regulatory agencies for the treatment of nonalcoholic fatty liver disease (NAFLD); incretin combination therapies are being developed for treatment of type 2 diabetes and research has moved to test their usefulness in NAFLD. AREAS COVERED We reviewed the literature on the effectiveness of dual and triple peptides combining receptor agonists of the glucagon-like peptide 1, the glucose-dependent insulinotropic peptide, and glucagon to treat NAFLD and its associated metabolic diseases, and/or the cardiovascular risk intimately connected with the cluster of the metabolic syndrome. Other combination peptides involved the glucagon-like peptide 2 receptor, the fibroblast growth factor 21, the cholecystokinin receptor 2, and the amylin receptor. EXPERT OPINION Both dual and triple agonists are promising, based on animal, pharmacokinetic and proof-of concept studies, showing effectiveness both in the presence and the absence of diabetes on a few validated surrogate NAFLD biomarkers, but the majority of studies are still in progress. Considering the long natural history of NAFLD, final proof of their efficacy on primary clinical liver outcomes might be also derived from the analysis of large databases of National Healthcare Systems or Insurance companies, when used in diabetes for improving glycemic control, after careful propensity-score matching.
Collapse
Affiliation(s)
- Lucia Brodosi
- IRCCS-Azienda Ospedaliera di Bologna Sant'Orsola-Malpighi, Via Massarenti 9, I-40138 Bologna, Italy
| | - Maria Letizia Petroni
- IRCCS-Azienda Ospedaliera di Bologna Sant'Orsola-Malpighi, Via Massarenti 9, I-40138 Bologna, Italy
| | - Giulio Marchesini
- Department of Medical and Surgical Sciences, Alma Mater University of Bologna, I-40138 Bologna, Italy
| |
Collapse
|
4
|
Wu Y, von Hauff IV, Jensen N, Rossner MJ, Wehr MC. Improved Split TEV GPCR β-arrestin-2 Recruitment Assays via Systematic Analysis of Signal Peptide and β-arrestin Binding Motif Variants. BIOSENSORS 2022; 13:48. [PMID: 36671883 PMCID: PMC9855867 DOI: 10.3390/bios13010048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/21/2022] [Accepted: 12/25/2022] [Indexed: 06/17/2023]
Abstract
G protein-coupled receptors (GPCRs) are major disease-relevant drug targets; robust monitoring of their activities upon drug treatment is key to drug discovery. The split TEV cell-based assay technique monitors the interaction of an activated GPCR with β-arrestin-2 through TEV protein fragment complementation using a luminescent signal as the readout. In this work, split TEV GPCR β-arrestin-2 recruitment assays were optimized to monitor the endogenous ligand-induced activities of six GPCRs (DRD1, DRD2, HTR2A, GCGR, AVPR2, and GLP1R). Each GPCR was tested in four forms; i.e., its wildtype form, a variant with a signal peptide (SP) to facilitate receptor expression, a variant containing the C-terminal tail from the V2 vasopressin receptor (V2R tail) to promote β-arrestin-2 recruitment, and a variant containing both the SP and V2R tail. These 24 GPCR variants were systematically tested for assay performance in four cell lines (HEK-293, PC12 Tet-Off, U-2 OS, and HeLa). We found that the assay performance differed significantly for each GPCR variant and was dependent on the cell line. We found that V2R improved the DRD2 split TEV assays and that HEK-293 cells were the preferred cell line across the GPCRs tested. When taking these considerations into account, the defined selection of assay modifications and conditions may improve the performance of drug development campaigns that apply the split TEV technique as a screening tool.
Collapse
Affiliation(s)
- Yuxin Wu
- Research Group Cell Signalling, Department of Psychiatry and Psychotherapy, University Hospital, Ludwig Maximilian University of Munich, Nussbaumstr. 7, 80336 Munich, Germany
| | - Isabelle V. von Hauff
- Research Group Cell Signalling, Department of Psychiatry and Psychotherapy, University Hospital, Ludwig Maximilian University of Munich, Nussbaumstr. 7, 80336 Munich, Germany
| | - Niels Jensen
- Section of Molecular Neurobiology, Department of Psychiatry and Psychotherapy, University Hospital, Ludwig Maximilian University of Munich, Nussbaumstr. 7, 80336 Munich, Germany
| | - Moritz J. Rossner
- Section of Molecular Neurobiology, Department of Psychiatry and Psychotherapy, University Hospital, Ludwig Maximilian University of Munich, Nussbaumstr. 7, 80336 Munich, Germany
- Systasy Bioscience GmbH, Balanstr. 6, 81699 Munich, Germany
| | - Michael C. Wehr
- Research Group Cell Signalling, Department of Psychiatry and Psychotherapy, University Hospital, Ludwig Maximilian University of Munich, Nussbaumstr. 7, 80336 Munich, Germany
- Systasy Bioscience GmbH, Balanstr. 6, 81699 Munich, Germany
| |
Collapse
|
5
|
Lednovich KR, Gough S, Brenner M, Qadri T, Layden BT. G
Protein‐Coupled Receptors in Metabolic Disease. GPCRS AS THERAPEUTIC TARGETS 2022:521-552. [DOI: 10.1002/9781119564782.ch15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
|
6
|
Al‐Zaid B, Chacko S, Ezeamuzie CI, Bünemann M, Krasel C, Karimian T, Lanzerstorfer P, Al‐Sabah S. Differential effects of glucose-dependent insulinotropic polypeptide receptor/glucagon-like peptide-1 receptor heteromerization on cell signaling when expressed in HEK-293 cells. Pharmacol Res Perspect 2022; 10:e01013. [PMID: 36177761 PMCID: PMC9523454 DOI: 10.1002/prp2.1013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/12/2022] [Indexed: 12/15/2022] Open
Abstract
The incretin hormones: glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are important regulators of many aspects of metabolism including insulin secretion. Their receptors (GIPR and GLP-1R) are closely related members of the secretin class of G-protein-coupled receptors. As both receptors are expressed on pancreatic β-cells there is at least the hypothetical possibility that they may form heteromers. In the present study, we investigated GIPR/GLP-1R heteromerization and the impact of GIPR on GLP-1R-mediated signaling and vice versa in HEK-293 cells. Real-time fluorescence resonance energy transfer (FRET) and bioluminescence resonance energy transfer (BRET) saturation experiments confirm that GLP-1R and GIPR form heteromers. Stimulation with 1 μM GLP-1 caused an increase in both FRET and BRET ratio, whereas stimulation with 1 μM GIP caused a decrease. The only other ligand tested to cause a significant change in BRET signal was the GLP-1 metabolite, GLP-1 (9-36). GIPR expression had no significant effect on mini-Gs recruitment to GLP-1R but significantly inhibited GLP-1 stimulated mini-Gq and arrestin recruitment. In contrast, the presence of GLP-1R improved GIP stimulated mini-Gs and mini-Gq recruitment to GIPR. These data support the hypothesis that GIPR and GLP-1R form heteromers with differential consequences on cell signaling.
Collapse
Affiliation(s)
- Bashaier Al‐Zaid
- Department of Pharmacology and Toxicology, Faculty of MedicineKuwait UniversityKuwait CityKuwait
| | - Siby Chacko
- Department of Pharmacology and Toxicology, Faculty of MedicineKuwait UniversityKuwait CityKuwait
| | | | - Moritz Bünemann
- School of Pharmacy, Institute for Pharmacology and ToxicologyThe Philipps University of MarburgMarburgGermany
| | - Cornelius Krasel
- School of Pharmacy, Institute for Pharmacology and ToxicologyThe Philipps University of MarburgMarburgGermany
| | - Tina Karimian
- University of Applied Sciences Upper Austria, School of EngineeringWelsAustria
| | - Peter Lanzerstorfer
- University of Applied Sciences Upper Austria, School of EngineeringWelsAustria
| | - Suleiman Al‐Sabah
- Department of Pharmacology and Toxicology, Faculty of MedicineKuwait UniversityKuwait CityKuwait
| |
Collapse
|
7
|
El Eid L, Reynolds CA, Tomas A, Ben Jones. Biased Agonism and Polymorphic Variation at the GLP-1 Receptor: Implications for the Development of Personalised Therapeutics. Pharmacol Res 2022; 184:106411. [PMID: 36007775 DOI: 10.1016/j.phrs.2022.106411] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 10/15/2022]
Abstract
Glucagon-like peptide-1 receptor (GLP-1R) is a well-studied incretin hormone receptor and target of several therapeutic drugs for type 2 diabetes (T2D), obesity and, more recently, cardiovascular disease. Some signalling pathways downstream of GLP-1R may be responsible for drug adverse effects such as nausea, while others mediate therapeutic outcomes of incretin-based T2D therapeutics. Understanding the interplay between different factors that alter signalling, trafficking, and receptor activity, including biased agonism, single nucleotide polymorphisms and structural modifications is key to develop the next-generation of personalised GLP-1R agonists. However, these interactions remain poorly described, especially for novel therapeutics such as dual and tri-agonists that target more than one incretin receptor. Comparison of GLP-1R structures in complex with G proteins and different peptide and non-peptide agonists has revealed novel insights into important agonist-residue interactions and networks crucial for receptor activation, recruitment of G proteins and engagement of specific signalling pathways. Here, we review the latest knowledge on GLP-1R structure and activation, providing structural evidence for biased agonism and delineating important networks associated with this phenomenon. We survey current biased agonists and multi-agonists at different stages of development, highlighting possible challenges in their translational potential. Lastly, we discuss findings related to non-synonymous genomic variants of GLP1R and the functional importance of specific residues involved in GLP-1R function. We propose that studies of GLP-1R polymorphisms, and specifically their effect on receptor dynamics and pharmacology in response to biased agonists, could have a significant impact in delineating precision medicine approaches and development of novel therapeutics.
Collapse
Affiliation(s)
- Liliane El Eid
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom
| | - Christopher A Reynolds
- Centre for Sport, Exercise and Life Sciences, Faculty of Health and Life Sciences, Coventry University, Alison Gingell Building, United Kingdom; School of Life Sciences, University of Essex, Colchester, United Kingdom
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom.
| | - Ben Jones
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom.
| |
Collapse
|
8
|
Mizera M, Latek D. Ligand-Receptor Interactions and Machine Learning in GCGR and GLP-1R Drug Discovery. Int J Mol Sci 2021; 22:ijms22084060. [PMID: 33920024 PMCID: PMC8071054 DOI: 10.3390/ijms22084060] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/31/2021] [Accepted: 04/07/2021] [Indexed: 12/03/2022] Open
Abstract
The large amount of data that has been collected so far for G protein-coupled receptors requires machine learning (ML) approaches to fully exploit its potential. Our previous ML model based on gradient boosting used for prediction of drug affinity and selectivity for a receptor subtype was compared with explicit information on ligand-receptor interactions from induced-fit docking. Both methods have proved their usefulness in drug response predictions. Yet, their successful combination still requires allosteric/orthosteric assignment of ligands from datasets. Our ligand datasets included activities of two members of the secretin receptor family: GCGR and GLP-1R. Simultaneous activation of two or three receptors of this family by dual or triple agonists is not a typical kind of information included in compound databases. A precise allosteric/orthosteric ligand assignment requires a continuous update based on new structural and biological data. This data incompleteness remains the main obstacle for current ML methods applied to class B GPCR drug discovery. Even so, for these two class B receptors, our ligand-based ML model demonstrated high accuracy (5-fold cross-validation Q2 > 0.63 and Q2 > 0.67 for GLP-1R and GCGR, respectively). In addition, we performed a ligand annotation using recent cryogenic-electron microscopy (cryo-EM) and X-ray crystallographic data on small-molecule complexes of GCGR and GLP-1R. As a result, we assigned GLP-1R and GCGR actives deposited in ChEMBL to four small-molecule binding sites occupied by positive and negative allosteric modulators and a full agonist. Annotated compounds were added to our recently released repository of GPCR data.
Collapse
|
9
|
Jones B, McGlone ER, Fang Z, Pickford P, Corrêa IR, Oishi A, Jockers R, Inoue A, Kumar S, Görlitz F, Dunsby C, French PMW, Rutter GA, Tan T, Tomas A, Bloom SR. Genetic and biased agonist-mediated reductions in β-arrestin recruitment prolong cAMP signaling at glucagon family receptors. J Biol Chem 2021; 296:100133. [PMID: 33268378 PMCID: PMC7948418 DOI: 10.1074/jbc.ra120.016334] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/29/2020] [Accepted: 12/01/2020] [Indexed: 01/20/2023] Open
Abstract
Receptors for the peptide hormones glucagon-like peptide-1 (GLP-1R), glucose-dependent insulinotropic polypeptide (GIPR), and glucagon (GCGR) are important regulators of insulin secretion and energy metabolism. GLP-1R agonists have been successfully deployed for the treatment of type 2 diabetes, but it has been suggested that their efficacy is limited by target receptor desensitization and downregulation due to recruitment of β-arrestins. Indeed, recently described GLP-1R agonists with reduced β-arrestin-2 recruitment have delivered promising results in preclinical and clinical studies. We therefore aimed to determine if the same phenomenon could apply to the closely related GIPR and GCGR. In HEK293 cells depleted of both β-arrestin isoforms the duration of G protein-dependent cAMP/PKA signaling was increased in response to the endogenous ligand for each receptor. Moreover, in wildtype cells, "biased" GLP-1, GCG, and GIP analogs with selective reductions in β-arrestin-2 recruitment led to reduced receptor endocytosis and increased insulin secretion over a prolonged stimulation period, although the latter effect was only seen at high agonist concentrations. Biased GCG analogs increased the duration of cAMP signaling, but this did not lead to increased glucose output from hepatocytes. Our study provides a rationale for the development of GLP-1R, GIPR, and GCGR agonists with reduced β-arrestin recruitment, but further work is needed to maximally exploit this strategy for therapeutic purposes.
Collapse
Affiliation(s)
- Ben Jones
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom.
| | - Emma Rose McGlone
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom
| | - Zijian Fang
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom
| | - Phil Pickford
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom
| | | | - Atsuro Oishi
- Université de Paris, Institut Cochin, INSERM, CNRS, Paris, France
| | - Ralf Jockers
- Université de Paris, Institut Cochin, INSERM, CNRS, Paris, France
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Sunil Kumar
- Department of Physics, Imperial College London, London, United Kingdom
| | - Frederik Görlitz
- Department of Physics, Imperial College London, London, United Kingdom
| | - Chris Dunsby
- Department of Physics, Imperial College London, London, United Kingdom
| | - Paul M W French
- Department of Physics, Imperial College London, London, United Kingdom
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Tricia Tan
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom.
| | - Stephen R Bloom
- Section of Endocrinology and Investigative Medicine, Imperial College London, London, United Kingdom
| |
Collapse
|
10
|
van Gastel J, Leysen H, Boddaert J, Vangenechten L, Luttrell LM, Martin B, Maudsley S. Aging-related modifications to G protein-coupled receptor signaling diversity. Pharmacol Ther 2020; 223:107793. [PMID: 33316288 DOI: 10.1016/j.pharmthera.2020.107793] [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] [Received: 10/07/2020] [Accepted: 11/26/2020] [Indexed: 02/06/2023]
Abstract
Aging is a highly complex molecular process, affecting nearly all tissue systems in humans and is the highest risk factor in developing neurodegenerative disorders such as Alzheimer's and Parkinson's disease, cardiovascular disease and Type 2 diabetes mellitus. The intense complexity of the aging process creates an incentive to develop more specific drugs that attenuate or even reverse some of the features of premature aging. As our current pharmacopeia is dominated by therapeutics that target members of the G protein-coupled receptor (GPCR) superfamily it may be prudent to search for effective anti-aging therapeutics in this fertile domain. Since the first demonstration of GPCR-based β-arrestin signaling, it has become clear that an enhanced appreciation of GPCR signaling diversity may facilitate the creation of therapeutics with selective signaling activities. Such 'biased' ligand signaling profiles can be effectively investigated using both standard molecular biological techniques as well as high-dimensionality data analyses. Through a more nuanced appreciation of the quantitative nature across the multiple dimensions of signaling bias that drugs possess, researchers may be able to further refine the efficacy of GPCR modulators to impact the complex aberrations that constitute the aging process. Identifying novel effector profiles could expand the effective pharmacopeia and assist in the design of precision medicines. This review discusses potential non-G protein effectors, and specifically their potential therapeutic suitability in aging and age-related disorders.
Collapse
Affiliation(s)
- Jaana van Gastel
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Faculty of Pharmacy, Biomedical and Veterinary Science, University of Antwerp, Antwerp, Belgium
| | - Hanne Leysen
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Faculty of Pharmacy, Biomedical and Veterinary Science, University of Antwerp, Antwerp, Belgium
| | - Jan Boddaert
- Molecular Pathology Group, Faculty of Medicine and Health Sciences, Laboratory of Cell Biology and Histology, Antwerp, Belgium
| | - Laura Vangenechten
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Louis M Luttrell
- Division of Endocrinology, Diabetes & Medical Genetics, Medical University of South Carolina, USA
| | - Bronwen Martin
- Faculty of Pharmacy, Biomedical and Veterinary Science, University of Antwerp, Antwerp, Belgium
| | - Stuart Maudsley
- Receptor Biology Lab, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Faculty of Pharmacy, Biomedical and Veterinary Science, University of Antwerp, Antwerp, Belgium.
| |
Collapse
|
11
|
Abstract
PURPOSE OF REVIEW Appetite control results from metabolic, behavioral, and environmental factors that influence hunger and the desire to eat. We summarize the latest advances in the hormonal and nutritional strategies to control appetite and reduce hunger. RECENT FINDINGS The fed-hunger-state is regulated by central and peripheric hormones, which modulate energy balance. Leptin, insulin, ghrelin, peptide YY (PYY), and other gut-derived peptides represent the main appetite controllers. The role of orexins, obestatin, and liver-expressed antimicrobial peptide 2 has been uncovered recently. New insights have demonstrated the role of hippocampal activity as a possible mechanism of action. Glucagon-like peptide 1 (GLP1) receptor agonists are well known agents controlling appetite. Association of GLP1 receptor agonist, PYY, or glucose-dependent insulinotropic polypeptide agonists have been tested as new approaches. Appetite-control hormones have also risen as factors involved in the efficacy of bariatric procedures. High-protein, ketogenic diet, and intermittent fasting have been described as nutritional strategies to reduce appetite, although the physiological mechanism and long-term safety remains unclear. SUMMARY Appetite control has been an important target for the treatment of obesity and associated disorders. New studies have demonstrated promising adoption of dietary approaches, hormone-based drugs, and bariatric surgery to control energy intake. Further research will establish a significant association, benefits, and safety of these new therapies.
Collapse
Affiliation(s)
- Rachel H Freire
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | |
Collapse
|
12
|
Al-Sabah S, Adi L, Bünemann M, Krasel C. The Effect of Cell Surface Expression and Linker Sequence on the Recruitment of Arrestin to the GIP Receptor. Front Pharmacol 2020; 11:1271. [PMID: 32903502 PMCID: PMC7438548 DOI: 10.3389/fphar.2020.01271] [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] [Received: 06/25/2020] [Accepted: 07/31/2020] [Indexed: 01/28/2023] Open
Abstract
The glucose-dependent insulinotropic polypeptide (GIP) and the glucagon-like peptide-1 (GLP-1) receptor are important targets in the treatment of both type 2 diabetes mellitus (T2DM) and obesity. Originally identified for their role in desensitization, internalization and recycling of G protein-coupled receptors (GPCRs), arrestins have since been shown to act as scaffolding proteins that allow GPCRs to signal in a G protein-independent manner. While GLP-1R has been reported to interact with arrestins, this aspect of cell signaling remains controversial for GIPR. Using a (FRET)-based assay we have previously shown that yellow fluorescent protein (YFP)-labeled GIPR does not recruit arrestin. This GIPR-YFP construct contained a 10 amino acid linker between the receptor and a XbaI restriction site upstream of the YFP. This linker was not present in the modified GIPR-SYFP2 used in subsequent FRET and bioluminescence resonance energy transfer (BRET) assays. However, its removal results in the introduction of a serine residue adjacent to the end of GIPR’s C-terminal tail which could potentially be a phosphorylation site. The resulting receptor was indeed able to recruit arrestin. To find out whether the serine/arginine (SR) coded by the XbaI site was indeed the source of the problem, it was substituted with glycine/glycine (GG) by site-directed mutagenesis. This substitution abolished arrestin recruitment in the BRET assay but only significantly reduced it in the FRET assay. In addition, we show that the presence of a N-terminal FLAG epitope and influenza hemagglutinin signal peptide were also required to detect arrestin recruitment to the GIPR, most likely by increasing receptor cell surface expression. These results demonstrate how arrestin recruitment assay configuration can dramatically alter the result. This becomes relevant when drug discovery programs aim to identify ligands with “biased agonist” properties.
Collapse
Affiliation(s)
- Suleiman Al-Sabah
- Department of Pharmacology and Toxicology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Lobna Adi
- Department of Pharmacology and Toxicology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Moritz Bünemann
- School of Pharmacy, Institute for Pharmacology and Toxicology, The Philipps University of Marburg, Marburg, Germany
| | - Cornelius Krasel
- School of Pharmacy, Institute for Pharmacology and Toxicology, The Philipps University of Marburg, Marburg, Germany
| |
Collapse
|
13
|
Holst JJ, Rosenkilde MM. GIP as a Therapeutic Target in Diabetes and Obesity: Insight From Incretin Co-agonists. J Clin Endocrinol Metab 2020; 105:dgaa327. [PMID: 32459834 PMCID: PMC7308078 DOI: 10.1210/clinem/dgaa327] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/23/2020] [Indexed: 12/21/2022]
Abstract
The 2 hormones responsible for the amplification of insulin secretion after oral as opposed to intravenous nutrient administration are the gut peptides, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). However, whereas GLP-1 also inhibits appetite and food intake and improves glucose regulation in patients with type 2 diabetes (T2DM), GIP seems to be devoid of these activities, although the 2 hormones as well as their receptors are highly related. In fact, numerous studies have suggested that GIP may promote obesity. However, chimeric peptides, combining elements of both peptides and capable of activating both receptors, have recently been demonstrated to have remarkable weight-losing and glucose-lowering efficacy in obese individuals with T2DM. At the same time, antagonists of the GIP receptor have been reported to reduce weight gain/cause weight loss in experimental animals including nonhuman primates. This suggests that both agonists and antagonist of the GIP receptor should be useful, at least for weight-losing therapy. How is this possible? We here review recent experimental evidence that agonist-induced internalization of the two receptors differs markedly and that modifications of the ligand structures, as in co-agonists, profoundly influence these cellular processes and may explain that an antagonist may activate while an agonist may block receptor signaling.
Collapse
Affiliation(s)
- Jens Juul Holst
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- NNF Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | | |
Collapse
|
14
|
Zhang J, Zhang Z, Ma C, Zeng L, Zhang Y, Wang P, Xu L. A novel thrombin-based triagonist with diabetes-protective and weight-lowering potential. Life Sci 2020; 256:117853. [PMID: 32470452 DOI: 10.1016/j.lfs.2020.117853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 05/23/2020] [Accepted: 05/24/2020] [Indexed: 01/10/2023]
Abstract
AIMS To investigate the diabetes-protective effect and weight-lowering potential of a novel long-acting triagonist at three metabolically related hormone receptors including glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), glucagon receptors. MAIN METHODS Triagonist were designed in an iterative manner from native GLP-1, GIP and Glucogan. Main peptide chain (termed TG peptides) and subsequently modified LTG peptides were synthesized via solid phase synthesis. In vitro receptor activity assay was performed to screen the TG peptide with most balanced potency on all three receptors. The in vitro biological activities of modified TG peptides were further investigated by albumin-binding measurement and proteolytic cleavage test. Subsequently, oral glucose tolerance test (OGTT), pharmacokinetic test and chronic study were subjected to the acute and long-term efficacy evaluation of selected fusion peptide, LTG-6. KEY FINDINGS TG-8 exhibited equally aligned constituent efficacy and supraphysiological potency on corresponding receptor without cross-reactivity. Modified TG-8, termed LTG-6, exerted the great binding affinity for human serum albumin and the enhanced rational controlled-release of TG-8 in vitro. Further OGTT in different gene knockout mice and diabetic mice demonstrated the promising hypoglycemic and insulinotropic abilities of LTG-6. After long-term treatment for 8 weeks, LTG-6 was proved superior to co-agonists to decrease the body weight and %HbA1c, improve reverse dyslipidemia and glycemic control in the DIO models. SIGNIFICANCE LTG-6, as a newly designed long-acting triagonist, holds potential to correct the obesity related metabolic disorders.
Collapse
Affiliation(s)
- Jingyu Zhang
- The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, PR China.
| | - Zhenyu Zhang
- Henan Institute of Disease Prevention, Zhengzhou 450052, PR China
| | - Cong Ma
- Shanghai Xuhui Central Hospital, Shanghai 200031, PR China
| | - Li Zeng
- The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, PR China
| | - Ying Zhang
- The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, PR China
| | - Peng Wang
- Zhengzhou University, 450052, PR China
| | - Lijuan Xu
- The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, PR China
| |
Collapse
|
15
|
Al-Zamel N, Al-Sabah S, Luqmani Y, Adi L, Chacko S, Schneider TD, Krasel C. Correction: Al-Zamel, N., et al. A Dual GLP-1/GIP Receptor Agonist Does Not Antagonize Glucagon at Its Receptor but May Act as a Biased Agonist at the GLP-1 Receptor. Int. J. Mol. Sci. 2019, 20, 3532. Int J Mol Sci 2020; 21:ijms21093357. [PMID: 32397501 PMCID: PMC7246989 DOI: 10.3390/ijms21093357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 05/07/2020] [Indexed: 11/16/2022] Open
Abstract
The author wishes to make the following correction to this paper [...].
Collapse
Affiliation(s)
- Noura Al-Zamel
- Department of Pharmacology & Toxicology, Faculty of Medicine, Kuwait University, PO Box 24923, 13110 Safat, Kuwait; (N.A.-Z.); (L.A.); (S.C.)
| | - Suleiman Al-Sabah
- Department of Pharmacology & Toxicology, Faculty of Medicine, Kuwait University, PO Box 24923, 13110 Safat, Kuwait; (N.A.-Z.); (L.A.); (S.C.)
- Correspondence: ; Tel.: +00-965-2463-6331
| | - Yunus Luqmani
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, PO Box 24923, 13110 Safat, Kuwait;
| | - Lobna Adi
- Department of Pharmacology & Toxicology, Faculty of Medicine, Kuwait University, PO Box 24923, 13110 Safat, Kuwait; (N.A.-Z.); (L.A.); (S.C.)
| | - Siby Chacko
- Department of Pharmacology & Toxicology, Faculty of Medicine, Kuwait University, PO Box 24923, 13110 Safat, Kuwait; (N.A.-Z.); (L.A.); (S.C.)
| | - Tom Dario Schneider
- Institute of Forensic Medicine, Department of Forensic Pharmacology and Toxicology, University of Zurich, 190/52 CH-8057 Zurich, Switzerland;
| | - Cornelius Krasel
- School of Pharmacy, Institute for Pharmacology and Toxicology, The Philipps University of Marburg, Karl-von-Frisch-Straße, 135033 Marburg, Germany;
| |
Collapse
|
16
|
Khan R, Tomas A, Rutter GA. Effects on pancreatic Beta and other Islet cells of the glucose-dependent insulinotropic polypeptide. Peptides 2020; 125:170201. [PMID: 31751656 DOI: 10.1016/j.peptides.2019.170201] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/11/2019] [Accepted: 11/11/2019] [Indexed: 12/13/2022]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is a gut-derived incretin that, in common with glucagon-like peptide-1 (GLP-1), has both insulin releasing and extra-pancreatic glucoregulatory actions. GIP is released in response to glucose or fat absorption and acts on the GIP receptor (GIPR) to potentiate insulin release from pancreatic beta cells. GIP has also been shown to promote beta cell survival and stimulate the release of GLP-1 from islet alpha cells. There is now evidence to suggest that low levels of GIP are secreted from alpha cells and may act in a paracrine manner to prime neighboring beta cells for insulin release. In addition, GIP acts on adipocytes to stimulate fat storage and can exert anorexigenic effects via actions in the hypothalamus. Contrary to GLP-1, the development of effective GIP-based T2D treatments has been hindered by poor bioavailability and attenuation of beta cell responses to GIP in some patients with sub-optimally controlled T2D. Recently, longer-acting GIP agonists that exhibit enzymatic stability, as well as dual GLP-1/GIP agonists which provide simultaneous improvement in glucose and weight control have been generated and successfully tested in animal T2D models. This, together with reports on GIP antagonists that may protect against obesity, has revived the interest on the GIP/GIPR axis as a potential anti-diabetic pathway. In this review, we summarize the known aspects of the effects of GIP on beta and other islet cells and discuss the most recent developments on GIP-based therapeutic agents for the improvement of beta cell function in T2D patients.
Collapse
Affiliation(s)
- Rabeet Khan
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| |
Collapse
|
17
|
Revisiting the Pharmacological Value of Glucagon: An Editorial for the Special Issue "The Biology and Pharmacology of Glucagon". Int J Mol Sci 2020; 21:ijms21020383. [PMID: 31936192 PMCID: PMC7013494 DOI: 10.3390/ijms21020383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 12/20/2019] [Indexed: 11/16/2022] Open
|