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Carney EF. The renal glucagon receptor is essential to kidney metabolic and homeostatic functions. Nat Rev Nephrol 2024; 20:203. [PMID: 38424242 DOI: 10.1038/s41581-024-00825-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
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Wang MY, Zhang Z, Zhao S, Onodera T, Sun XN, Zhu Q, Li C, Li N, Chen S, Paredes M, Gautron L, Charron MJ, Marciano DK, Gordillo R, Drucker DJ, Scherer PE. Downregulation of the kidney glucagon receptor, essential for renal function and systemic homeostasis, contributes to chronic kidney disease. Cell Metab 2024; 36:575-597.e7. [PMID: 38237602 PMCID: PMC10932880 DOI: 10.1016/j.cmet.2023.12.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 09/10/2023] [Accepted: 12/19/2023] [Indexed: 02/12/2024]
Abstract
The glucagon receptor (GCGR) in the kidney is expressed in nephron tubules. In humans and animal models with chronic kidney disease, renal GCGR expression is reduced. However, the role of kidney GCGR in normal renal function and in disease development has not been addressed. Here, we examined its role by analyzing mice with constitutive or conditional kidney-specific loss of the Gcgr. Adult renal Gcgr knockout mice exhibit metabolic dysregulation and a functional impairment of the kidneys. These mice exhibit hyperaminoacidemia associated with reduced kidney glucose output, oxidative stress, enhanced inflammasome activity, and excess lipid accumulation in the kidney. Upon a lipid challenge, they display maladaptive responses with acute hypertriglyceridemia and chronic proinflammatory and profibrotic activation. In aged mice, kidney Gcgr ablation elicits widespread renal deposition of collagen and fibronectin, indicative of fibrosis. Taken together, our findings demonstrate an essential role of the renal GCGR in normal kidney metabolic and homeostatic functions. Importantly, mice deficient for kidney Gcgr recapitulate some of the key pathophysiological features of chronic kidney disease.
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Affiliation(s)
- May-Yun Wang
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Zhuzhen Zhang
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shangang Zhao
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Sam and Ann Barshop Institute for Longevity and Aging Studies, Division of Endocrinology, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Toshiharu Onodera
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xue-Nan Sun
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Qingzhang Zhu
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chao Li
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Na Li
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shiuhwei Chen
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Megan Paredes
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Laurent Gautron
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Maureen J Charron
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Denise K Marciano
- Division of Nephrology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ruth Gordillo
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Daniel J Drucker
- Lunenfeld-TanenbaumResearchInstitute, Mt. Sinai Hospital, Toronto, ON M5G1X5, Canada; Department of Medicine, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Philipp E Scherer
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Melander SA, Kayed A, Andreassen KV, Karsdal MA, Henriksen K. OXM-104, a potential candidate for the treatment of obesity, NASH and type 2 diabetes. Eur J Pharmacol 2024; 962:176215. [PMID: 38056618 DOI: 10.1016/j.ejphar.2023.176215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 11/08/2023] [Accepted: 11/16/2023] [Indexed: 12/08/2023]
Abstract
OBJECTIVE Dual glucagon-like peptide-1 (GLP-1) and glucagon receptor agonists are therapeutic agents with an interesting liver-specific mode of action suitable for metabolic complications. In this study, dual GLP-1 and glucagon receptor agonist OXM-104 is compared head-to-head with the once-daily dual GLP-1 and glucagon receptor agonist cotadutide and GLP-1 receptor agonist semaglutide to explore the metabolic efficacy of OXM-104. METHODS The in vitro potencies of OXM-104, cotadutide and semaglutide were assessed using reporter assays. In addition, in vivo efficacy was investigated using mouse models of diet-induced obesity (DIO mice), diabetes (db/db mice) and diet-induced NASH mice (MS-NASH). RESULTS OXM-104 was found to only activate the GLP-1 and glucagon with no cross-reactivity at the (GIP) receptor. Cotadutide was also found to activate the GLP-1 and glucagon receptors, whereas semaglutide only showed activity at the GLP-1 receptor. OXM-104, cotadutide, and semaglutide elicited marked reductions in body weight and improved glucose control. In contrast, hepatoprotective effects, i.e., reductions in steatosis and fibrosis, as well as liver fibrotic biomarkers, were more prominent with OXM-104 and cotadutide than those seen with semaglutide, demonstrated by an improved NAFLD activity score (NAS) by OXM-104 and cotadutide, underlining the importance of the glucagon receptor. CONCLUSION These results show that dual GLP-1 and glucagon receptor agonism is superior to GLP-1 alone. OXM-104 was found to be a promising therapeutic candidate for the treatment of metabolic complications such as obesity, type 2 diabetes and NASH.
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Affiliation(s)
| | | | | | | | - Kim Henriksen
- Nordic Bioscience, 2730 Herlev, Denmark; KeyBioscience AG, Stans, Switzerland
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Wang P, Wei R, Cui X, Jiang Z, Yang J, Zu L, Hong T. Fatty acid β-oxidation and mitochondrial fusion are involved in cardiac microvascular endothelial cell protection induced by glucagon receptor antagonism in diabetic mice. J Diabetes 2023; 15:1081-1094. [PMID: 37596940 PMCID: PMC10755618 DOI: 10.1111/1753-0407.13458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/15/2023] [Accepted: 07/26/2023] [Indexed: 08/21/2023] Open
Abstract
INTRODUCTION The role of cardiac microvascular endothelial cells (CMECs) in diabetic cardiomyopathy is not fully understood. We aimed to investigate whether a glucagon receptor (GCGR) monoclonal antibody (mAb) ameliorated diabetic cardiomyopathy and clarify whether and how CMECs participated in the process. RESEARCH DESIGN AND METHODS The db/db mice were treated with GCGR mAb or immunoglobulin G (as control) for 4 weeks. Echocardiography was performed to evaluate cardiac function. Immunofluorescent staining was used to determine microvascular density. The proteomic signature in isolated primary CMECs was analyzed by using tandem mass tag-based quantitative proteomic analysis. Some target proteins were verified by using western blot. RESULTS Compared with db/m mice, cardiac microvascular density and left ventricular diastolic function were significantly reduced in db/db mice, and this reduction was attenuated by GCGR mAb treatment. A total of 199 differentially expressed proteins were upregulated in db/db mice versus db/m mice and downregulated in GCGR mAb-treated db/db mice versus db/db mice. The enrichment analysis demonstrated that fatty acid β-oxidation and mitochondrial fusion were the key pathways. The changes of the related proteins carnitine palmitoyltransferase 1B, optic atrophy type 1, and mitofusin-1 were further verified by using western blot. The levels of these three proteins were upregulated in db/db mice, whereas this upregulation was attenuated by GCGR mAb treatment. CONCLUSION GCGR antagonism has a protective effect on CMECs and cardiac diastolic function in diabetic mice, and this beneficial effect may be mediated via inhibiting fatty acid β-oxidation and mitochondrial fusion in CMECs.
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Affiliation(s)
- Peng Wang
- Department of Endocrinology and Metabolism, Department of Cardiology and Institute of Vascular MedicinePeking University Third HospitalBeijingChina
- NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides; Key Laboratory of Molecular Cardiovascular Science, Ministry of EducationBeijing Key Laboratory of Cardiovascular Receptors ResearchBeijingChina
| | - Rui Wei
- Department of Endocrinology and Metabolism, Department of Cardiology and Institute of Vascular MedicinePeking University Third HospitalBeijingChina
| | - Xiaona Cui
- Department of Endocrinology and Metabolism, Department of Cardiology and Institute of Vascular MedicinePeking University Third HospitalBeijingChina
| | - Zongzhe Jiang
- Department of Endocrinology and MetabolismThe Affiliated Hospital of Southwest Medical UniversityLuzhouChina
| | - Jin Yang
- Department of Endocrinology and Metabolism, Department of Cardiology and Institute of Vascular MedicinePeking University Third HospitalBeijingChina
| | - Lingyun Zu
- Department of Endocrinology and Metabolism, Department of Cardiology and Institute of Vascular MedicinePeking University Third HospitalBeijingChina
- NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides; Key Laboratory of Molecular Cardiovascular Science, Ministry of EducationBeijing Key Laboratory of Cardiovascular Receptors ResearchBeijingChina
| | - Tianpei Hong
- Department of Endocrinology and Metabolism, Department of Cardiology and Institute of Vascular MedicinePeking University Third HospitalBeijingChina
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Folli F, Finzi G, Manfrini R, Galli A, Casiraghi F, Centofanti L, Berra C, Fiorina P, Davalli A, La Rosa S, Perego C, Higgins PB. Mechanisms of action of incretin receptor based dual- and tri-agonists in pancreatic islets. Am J Physiol Endocrinol Metab 2023; 325:E595-E609. [PMID: 37729025 PMCID: PMC10874655 DOI: 10.1152/ajpendo.00236.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/15/2023] [Accepted: 09/16/2023] [Indexed: 09/22/2023]
Abstract
Simultaneous activation of the incretin G-protein-coupled receptors (GPCRs) via unimolecular dual-receptor agonists (UDRA) has emerged as a new therapeutic approach for type 2 diabetes. Recent studies also advocate triple agonism with molecules also capable of binding the glucagon receptor. In this scoping review, we discuss the cellular mechanisms of action (MOA) underlying the actions of these novel and therapeutically important classes of peptide receptor agonists. Clinical efficacy studies of several UDRAs have demonstrated favorable results both as monotherapies and when combined with approved hypoglycemics. Although the additive insulinotropic effects of dual glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic peptide receptor (GIPR) agonism were anticipated based on the known actions of either glucagon-like peptide-1 (GLP-1) or glucose-dependent insulinotropic peptide (GIP) alone, the additional benefits from GCGR were largely unexpected. Whether additional synergistic or antagonistic interactions among these G-protein receptor signaling pathways arise from simultaneous stimulation is not known. The signaling pathways affected by dual- and tri-agonism require more trenchant investigation before a comprehensive understanding of the cellular MOA. This knowledge will be essential for understanding the chronic efficacy and safety of these treatments.
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Affiliation(s)
- Franco Folli
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milan, Italy
- Unit of Diabetes, Endocrinology and Metabolism, San Paolo Hospital, ASST Santi Paolo e Carlo, Milan, Italy
| | - Giovanna Finzi
- Unit of Pathology, Department of Oncology, ASST Sette Laghi, Varese, Italy
| | - Roberto Manfrini
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milan, Italy
- Unit of Diabetes, Endocrinology and Metabolism, San Paolo Hospital, ASST Santi Paolo e Carlo, Milan, Italy
| | - Alessandra Galli
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Francesca Casiraghi
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milan, Italy
| | - Lucia Centofanti
- Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milan, Italy
| | - Cesare Berra
- IRCCS MultiMedica, Sesto San Giovanni, Milan, Italy
| | - Paolo Fiorina
- International Center for T1D, Pediatric Clinical Research Center Romeo ed Enrica Invernizzi, DIBIC, Università di Milano, Milan, Italy
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States
- Division of Endocrinology, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Alberto Davalli
- Diabetes and Endocrinology Unit, Department of Internal Medicine, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Stefano La Rosa
- Unit of Pathology, Department of Medicine and Technological Innovation, University of Insubria, Varese, Italy
| | - Carla Perego
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Paul B Higgins
- Department of Life & Physical Sciences, Atlantic Technological University, Letterkenny, Ireland
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Shang J, Yan W, Cui X, Ma W, Wang Z, Liu N, Yi X, Guo T, Wei X, Sun Y, Hu H, Cui W, Chen L. Schisandrin B, a potential GLP-1R agonist, exerts anti-diabetic effects by stimulating insulin secretion. Mol Cell Endocrinol 2023; 577:112029. [PMID: 37495090 DOI: 10.1016/j.mce.2023.112029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/21/2023] [Accepted: 07/23/2023] [Indexed: 07/28/2023]
Abstract
Diabetes mellitus is a metabolic disease that is characterized by elevated blood sugar. Although glucagon-like peptide-1 receptor agonists (GLP-1RA) lower blood glucose in a glucose-dependent manner, most of them are macromolecule polypeptides. Macromolecular peptides are relatively expensive and inconvenient compared with small molecules. Therefore, this study sought to identify the small molecules binding to GLP-1R via cell membrane chromatography (CMC), confirm their agonistic activity, and further study its beneficial effects in a mouse model of type 2 diabetes mellitus (T2DM) induced by a combination of high-fat diet and streptozotocin. We used CMC, calcium imaging and molecular docking techniques to screen and identify the potential small molecule Schisandrin B (Sch B), which exhibits a strong binding effect to GLP-1R, from the small molecule library of traditional Chinese medicine. Through in-vitro experiments, we found that Sch B stimulated insulin secretion in β-TC-6 cells, while GLP-1R antagonist Exendin9-39, adenylate cyclase inhibitor SQ22536, and protein kinase A (PKA) inhibitor H89 could significantly inhibit the insulin secretion induced by Sch B. In vivo, Sch B significantly improved fasting blood glucose levels, intraperitoneal glucose tolerance test damage, and the status of pancreatic tissue damage, and reduced serum insulin levels, total cholesterol, triglyceride and low density lipoprotein in T2DM mice. These results indicate that Sch B alleviates T2DM by promoting insulin release through the GLP-1R/cAMP/PKA signaling pathway, suggesting that Sch B may be a potential GLP-1RA, which is expected to provide a new therapeutic strategy for the prevention and treatment of T2DM.
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Affiliation(s)
- Jia Shang
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Wenhui Yan
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, 710061, China
| | - Xin Cui
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Weina Ma
- School of Pharmacy, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China
| | - Zhuanzhuan Wang
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Na Liu
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Xinyao Yi
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Tingli Guo
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Xiaotong Wei
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Yuzhuo Sun
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Hao Hu
- Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, 710061, China
| | - Wei Cui
- Department of Endocrinology and Second Department of Geriatrics, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China; International Obesity and Metabolic Disease Research Center (IOMC), Xi'an Jiaotong University, Xi'an, 710061, China.
| | - Lina Chen
- Department of Endocrinology and Second Department of Geriatrics, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China; Department of Pharmacology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, 710061, China; Institute of Cardiovascular Sciences, Translational Medicine Institute, Xi'an Jiaotong University, Xi'an, 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, 710061, China; International Obesity and Metabolic Disease Research Center (IOMC), Xi'an Jiaotong University, Xi'an, 710061, China; Cardiometabolic Innovation Center, Ministry of Education, Xi'an, 710061, China.
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7
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Vishnoi S, Bhattacharya S, Walsh EM, Okoh GI, Thompson D. Computational Peptide Design Cotargeting Glucagon and Glucagon-like Peptide-1 Receptors. J Chem Inf Model 2023; 63:4934-4947. [PMID: 37523325 PMCID: PMC10428222 DOI: 10.1021/acs.jcim.3c00752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Indexed: 08/02/2023]
Abstract
Peptides are sustainable alternatives to conventional therapeutics for G protein-coupled receptor (GPCR) linked disorders, promising biocompatible and tailorable next-generation therapeutics for metabolic disorders including type-2 diabetes, as agonists of the glucagon receptor (GCGR) and the glucagon-like peptide-1 receptor (GLP-1R). However, single agonist peptides activating GLP-1R to stimulate insulin secretion also suppress obesity-linked glucagon release. Hence, bioactive peptides cotargeting GCGR and GLP-1R may remediate the blood glucose and fatty acid metabolism imbalance, tackling both diabetes and obesity to supersede current monoagonist therapy. Here, we design and model optimized peptide sequences starting from peptide sequences derived from earlier phage-displayed library screening, identifying those with predicted molecular binding profiles for dual agonism of GCGR and GLP-1R. We derive design rules from extensive molecular dynamics simulations based on peptide-receptor binding. Our newly designed coagonist peptide exhibits improved predicted coupled binding affinity for GCGR and GLP-1R relative to endogenous ligands and could in the future be tested experimentally, which may provide superior glycemic and weight loss control.
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Affiliation(s)
- Shubham Vishnoi
- Department
of Physics, Bernal Institute, University
of Limerick, Limerick V94T9PX, Ireland
| | - Shayon Bhattacharya
- Department
of Physics, Bernal Institute, University
of Limerick, Limerick V94T9PX, Ireland
| | | | | | - Damien Thompson
- Department
of Physics, Bernal Institute, University
of Limerick, Limerick V94T9PX, Ireland
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8
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Sipos B, Klöppel G. Glucagon cell hyperplasia and neoplasia: a recently recognized endocrine receptor disease. Endocr Relat Cancer 2023; 30:e230032. [PMID: 37260318 DOI: 10.1530/erc-23-0032] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Accepted: 05/22/2023] [Indexed: 06/02/2023]
Abstract
Glucagon cell hyperplasia and neoplasia (GCHN) is the name of an endocrine receptor disease, whose morphology was first described in 2006. Three years later, this rare disease was found to be to be caused by an inactivating mutation of the glucagon receptor (GCGR) gene. Functionally, the genetic defect mainly affects glucagon signaling in the liver with changes in the metabolism of glycogen, fatty acids and amino acids. Recent results of several studies in GCGR knockout mice suggested that elevated serum amino acid levels probably stimulate glucagon cell hyperplasia with subsequent transformation into glucagon cell neoplasia. This process leads over time to numerous small and some large pancreatic neuroendocrine tumors which are potentially malignant. Despite high glucagon serum levels, the patients develop no glucagonoma syndrome. In 2015, GCHN was identified as an autosomal recessive hereditary disorder.
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Affiliation(s)
- Bence Sipos
- Department of Medical Oncology and Pneumology (Internal Medicine VIII), University Hospital Tubingen, Tübingen, Germany
- ENETS Center of Excellence, University Hospital Tübingen, Tübingen, Germany
| | - Günter Klöppel
- Department of Pathology, Technical University Munich, Munich, Germany
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9
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Chen K, Zhang C, Lin S, Yan X, Cai H, Yi C, Ma L, Chu X, Liu Y, Zhu Y, Han S, Zhao Q, Wu B. Tail engagement of arrestin at the glucagon receptor. Nature 2023; 620:904-910. [PMID: 37558880 PMCID: PMC10447241 DOI: 10.1038/s41586-023-06420-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 07/11/2023] [Indexed: 08/11/2023]
Abstract
Arrestins have pivotal roles in regulating G protein-coupled receptor (GPCR) signalling by desensitizing G protein activation and mediating receptor internalization1,2. It has been proposed that the arrestin binds to the receptor in two different conformations, 'tail' and 'core', which were suggested to govern distinct processes of receptor signalling and trafficking3,4. However, little structural information is available for the tail engagement of the arrestins. Here we report two structures of the glucagon receptor (GCGR) bound to β-arrestin 1 (βarr1) in glucagon-bound and ligand-free states. These structures reveal a receptor tail-engaged binding mode of βarr1 with many unique features, to our knowledge, not previously observed. Helix VIII, instead of the receptor core, has a major role in accommodating βarr1 by forming extensive interactions with the central crest of βarr1. The tail-binding pose is further defined by a close proximity between the βarr1 C-edge and the receptor helical bundle, and stabilized by a phosphoinositide derivative that bridges βarr1 with helices I and VIII of GCGR. Lacking any contact with the arrestin, the receptor core is in an inactive state and loosely binds to glucagon. Further functional studies suggest that the tail conformation of GCGR-βarr governs βarr recruitment at the plasma membrane and endocytosis of GCGR, and provides a molecular basis for the receptor forming a super-complex simultaneously with G protein and βarr to promote sustained signalling within endosomes. These findings extend our knowledge about the arrestin-mediated modulation of GPCR functionalities.
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Affiliation(s)
- Kun Chen
- State Key Laboratory of Drug Research, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chenhui Zhang
- State Key Laboratory of Drug Research, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shuling Lin
- State Key Laboratory of Drug Research, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xinyu Yan
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Heng Cai
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
| | - Cuiying Yi
- State Key Laboratory of Drug Research, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Limin Ma
- State Key Laboratory of Drug Research, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xiaojing Chu
- State Key Laboratory of Drug Research, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yuchen Liu
- State Key Laboratory of Drug Research, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ya Zhu
- Lingang Laboratory, Shanghai, China
| | - Shuo Han
- State Key Laboratory of Drug Research, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
| | - Qiang Zhao
- State Key Laboratory of Drug Research, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China.
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan, China.
| | - Beili Wu
- State Key Laboratory of Drug Research, State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
- School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
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10
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Ouberai MM, Gomes Dos Santos AL, Kinna S, Hornigold DC, Baker D, Naylor J, Liang L, Corkill DJ, Welland ME. Self-assembled GLP-1/glucagon peptide nanofibrils prolong inhibition of food intake. Front Endocrinol (Lausanne) 2023; 14:1217021. [PMID: 37554763 PMCID: PMC10406450 DOI: 10.3389/fendo.2023.1217021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/27/2023] [Indexed: 08/10/2023] Open
Abstract
Introduction Oxyntomodulin (Oxm) hormone peptide has a number of beneficial effects on nutrition and metabolism including increased energy expenditure and reduced body weight gain. Despite its many advantages as a potential therapeutic agent, Oxm is subjected to rapid renal clearance and protease degradation limiting its clinical application. Previously, we have shown that subcutaneous administration of a fibrillar Oxm formulation can significantly prolong its bioactivity in vivo from a few hours to a few days. Methods We used a protease resistant analogue of Oxm, Aib2-Oxm, to form nanfibrils depot and improve serum stability of released peptide. The nanofibrils and monomeric peptide in solution were characterized by spectroscopic, microscopic techniques, potency assay, QCM-D and in vivo studies. Results We show that in comparison to Oxm, Aib2-Oxm fibrils display a slower elongation rate requiring higher ionic strength solutions, and a higher propensity to dissociate. Upon subcutaneous administration of fibrillar Aib2-Oxm in rodents, a 5-fold increase in bioactivity relative to fibrillar Oxm and a significantly longer bioactivity than free Aib2-Oxm were characterized. Importantly, a decrease in food intake was observed up to 72-hour post-administration, which was not seen for free Aib2-Oxm. Conclusion Our findings provides compelling evidence for the development of long-lasting peptide fibrillar formulations that yield extended plasma exposure and enhanced in vivo pharmacological response.
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Affiliation(s)
- Myriam M. Ouberai
- Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Ana L. Gomes Dos Santos
- Advanced Drug Delivery, Pharmaceutical Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - Sonja Kinna
- Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - David C. Hornigold
- Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - David Baker
- Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - Jacqueline Naylor
- Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Lihuan Liang
- Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - Dominic J. Corkill
- Bioscience In Vivo, Research and Early Development, Respiratory & Immunology, BioPharmaceuticals, R&D, AstraZeneca, Cambridge, United Kingdom
| | - Mark E. Welland
- Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
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11
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Hope DCD, Tan TMM. Glucagon and energy expenditure; Revisiting amino acid metabolism and implications for weight loss therapy. Peptides 2023; 162:170962. [PMID: 36736539 DOI: 10.1016/j.peptides.2023.170962] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023]
Abstract
Glucagon receptor (GCGR)-targeted multi-agonists are being developed for the treatment of obesity and metabolic disease. GCGR activity is utilised for its favourable weight loss and metabolic properties, including increased energy expenditure (EE) and hepatic lipid metabolism. GLP1R and GIPR activities are increasingly present in a multi-agonist strategy. Due to the compound effect of increased satiety, reduced food intake and increased energy expenditure, the striking weight loss effects of these multi-agonists has been demonstrated in pre-clinical models of obesity. The precise contribution and mechanism of GCGR activity to enhanced energy expenditure and weight loss in both rodents and humans is not fully understood. In this review, our understanding of glucagon-mediated EE is explored, and an amino acid-centric paradigm contributing to this phenomenon is presented. The current progress of GCGR-targeted multi-agonists in development is also highlighted with a focus on the implications of glucagon-stimulated hypoaminoacidemia.
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Affiliation(s)
- D C D Hope
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - T M-M Tan
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom.
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12
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Krishna Kumar K, O'Brien ES, Habrian CH, Latorraca NR, Wang H, Tuneew I, Montabana E, Marqusee S, Hilger D, Isacoff EY, Mathiesen JM, Kobilka BK. Negative allosteric modulation of the glucagon receptor by RAMP2. Cell 2023; 186:1465-1477.e18. [PMID: 37001505 PMCID: PMC10144504 DOI: 10.1016/j.cell.2023.02.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/23/2023] [Accepted: 02/17/2023] [Indexed: 04/03/2023]
Abstract
Receptor activity-modifying proteins (RAMPs) modulate the activity of many Family B GPCRs. We show that RAMP2 directly interacts with the glucagon receptor (GCGR), a Family B GPCR responsible for blood sugar homeostasis, and broadly inhibits receptor-induced downstream signaling. HDX-MS experiments demonstrate that RAMP2 enhances local flexibility in select locations in and near the receptor extracellular domain (ECD) and in the 6th transmembrane helix, whereas smFRET experiments show that this ECD disorder results in the inhibition of active and intermediate states of the intracellular surface. We determined the cryo-EM structure of the GCGR-Gs complex at 2.9 Å resolution in the presence of RAMP2. RAMP2 apparently does not interact with GCGR in an ordered manner; however, the receptor ECD is indeed largely disordered along with rearrangements of several intracellular hallmarks of activation. Our studies suggest that RAMP2 acts as a negative allosteric modulator of GCGR by enhancing conformational sampling of the ECD.
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Affiliation(s)
- Kaavya Krishna Kumar
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA
| | - Evan S O'Brien
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA
| | - Chris H Habrian
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA
| | - Naomi R Latorraca
- Department of Molecular and Cell Biology, University of California Berkeley, CA 94720, USA
| | - Haoqing Wang
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA
| | - Inga Tuneew
- Zealand Pharma A/S, Sydmarken 11, Soborg 2860, Denmark
| | - Elizabeth Montabana
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA
| | - Susan Marqusee
- Department of Molecular and Cell Biology, University of California Berkeley, CA 94720, USA; QB3 Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley CA 94720, USA; Department of Chemistry, University of California, Berkeley, Berkeley CA 94720, USA
| | - Daniel Hilger
- Department of Pharmaceutical Chemistry, Philipps-University Marburg, Marbacher Weg 6, Marburg 35037, Germany
| | - Ehud Y Isacoff
- Department of Molecular and Cell Biology, University of California Berkeley, CA 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley CA 94720, USA
| | | | - Brian K Kobilka
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA.
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13
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Zhang X, Cai Y, Yao Z, Chi H, Li Y, Shi J, Zhou Z, Sun L. Discovery of novel OXM-based glucagon-like peptide 1 (GLP-1)/glucagon receptor dual agonists. Peptides 2023; 161:170948. [PMID: 36646385 DOI: 10.1016/j.peptides.2023.170948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
Novel glucagon receptor (GCGR) and glucagon-like peptide 1 receptor (GLP-1R) dual agonists are reported to have improved efficacy over GLP-1R mono-agonists in treating type 2 diabetes (T2DM) and obesity. Here, we describe the discovery of a novel oxyntomodulin (OXM) based GLP-1R/GCGR dual agonist with potent and balanced potency toward GLP-1R and GCGR. The lead peptide OXM-7 was obtained via stepwise rational design and long-acting modification. In ICR and db/db mice, OXM-7 exhibited prominent acute and long-acting hypoglycemic effects. In diet-induced obesity (DIO) mice, twice-daily administration of OXM-7 produced significant weight loss, normalized lipid metabolism, and improved glucose control. In DIO-nonalcoholic steatohepatitis (NASH) mice, OXM-7 treatment significantly reversed hepatic steatosis, and reduced serum and hepatic lipid levels. These preclinical data suggest the therapeutic potential of OXM-7 as a novel anti-diabetic, anti-steatotic and/or anti-obesity agent.
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Affiliation(s)
- Xiaolong Zhang
- Food and Pharmaceutical Research Institute, Jiangsu Food & Pharmaceutical Science College, Huaian 223003, Jiangsu, PR China
| | - Yuchen Cai
- School of Engineering, China Pharmaceutical University, Nanjing 210009, Jiangsu, PR China
| | - Zhihong Yao
- Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, Zhejiang, PR China
| | - Heng Chi
- Food and Pharmaceutical Research Institute, Jiangsu Food & Pharmaceutical Science College, Huaian 223003, Jiangsu, PR China
| | - Yan Li
- Food and Pharmaceutical Research Institute, Jiangsu Food & Pharmaceutical Science College, Huaian 223003, Jiangsu, PR China
| | - Jingjing Shi
- Food and Pharmaceutical Research Institute, Jiangsu Food & Pharmaceutical Science College, Huaian 223003, Jiangsu, PR China
| | - Zhongbo Zhou
- School of Pharmacy, Youjiang Medical University for Nationalities, 98 Chengxiang Road, Baise 533000, Guangxi, PR China.
| | - Lidan Sun
- Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, Jiaxing 314001, Zhejiang, PR China.
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14
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Darbalaei S, Chang RL, Zhou QT, Chen Y, Dai AT, Wang MW, Yang DH. Effects of site-directed mutagenesis of GLP-1 and glucagon receptors on signal transduction activated by dual and triple agonists. Acta Pharmacol Sin 2023; 44:421-433. [PMID: 35953646 PMCID: PMC9889767 DOI: 10.1038/s41401-022-00962-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/17/2022] [Indexed: 02/04/2023] Open
Abstract
The paradigm of one drug against multiple targets, known as unimolecular polypharmacology, offers the potential to improve efficacy while overcoming some adverse events associated with the treatment. This approach is best exemplified by targeting two or three class B1 G protein-coupled receptors, namely, glucagon-like peptide-1 receptor (GLP-1R), glucagon receptor (GCGR) and glucose-dependent insulinotropic polypeptide receptor for treatment of type 2 diabetes and obesity. Some of the dual and triple agonists have already shown initial successes in clinical trials, although the molecular mechanisms underlying their multiplexed pharmacology remain elusive. In this study we employed structure-based site-directed mutagenesis together with pharmacological assays to compare agonist efficacy across two key signaling pathways, cAMP accumulation and ERK1/2 phosphorylation (pERK1/2). Three dual agonists (peptide 15, MEDI0382 and SAR425899) and one triple agonist (peptide 20) were evaluated at GLP-1R and GCGR, relative to the native peptidic ligands (GLP-1 and glucagon). Our results reveal the existence of residue networks crucial for unimolecular agonist-mediated receptor activation and their distinct signaling patterns, which might be useful to the rational design of biased drug leads.
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Affiliation(s)
- Sanaz Darbalaei
- The National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences (CAS), Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ru-Lue Chang
- School of Pharmacy, Fudan University, Shanghai, 201203, China
| | - Qing-Tong Zhou
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Yan Chen
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - An-Tao Dai
- The National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences (CAS), Shanghai, 201203, China
| | - Ming-Wei Wang
- School of Pharmacy, Fudan University, Shanghai, 201203, China.
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.
- Research Center for Deepsea Bioresources, Sanya, 572025, China.
- Department of Chemistry, School of Science, The University of Tokyo, Tokyo, 113-0033, Japan.
| | - De-Hua Yang
- The National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences (CAS), Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Research Center for Deepsea Bioresources, Sanya, 572025, China.
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15
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Wang K, Cui X, Li F, Xia L, Wei T, Liu J, Fu W, Yang J, Hong T, Wei R. Glucagon receptor blockage inhibits β-cell dedifferentiation through FoxO1. Am J Physiol Endocrinol Metab 2023; 324:E97-E113. [PMID: 36383639 DOI: 10.1152/ajpendo.00101.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glucagon-secreting pancreatic α-cells play pivotal roles in the development of diabetes. Glucagon promotes insulin secretion from β-cells. However, the long-term effect of glucagon on the function and phenotype of β-cells had remained elusive. In this study, we found that long-term glucagon intervention or glucagon intervention with the presence of palmitic acid downregulated β-cell-specific markers and inhibited insulin secretion in cultured β-cells. These results suggested that glucagon induced β-cell dedifferentiation under pathological conditions. Glucagon blockage by a glucagon receptor (GCGR) monoclonal antibody (mAb) attenuated glucagon-induced β-cell dedifferentiation. In primary islets, GCGR mAb treatment upregulated β-cell-specific markers and increased insulin content, suggesting that blockage of endogenous glucagon-GCGR signaling inhibited β-cell dedifferentiation. To investigate the possible mechanism, we found that glucagon decreased FoxO1 expression. FoxO1 inhibitor mimicked the effect of glucagon, whereas FoxO1 overexpression reversed the glucagon-induced β-cell dedifferentiation. In db/db mice and β-cell lineage-tracing diabetic mice, GCGR mAb lowered glucose level, upregulated plasma insulin level, increased β-cell area, and inhibited β-cell dedifferentiation. In aged β-cell-specific FoxO1 knockout mice (with the blood glucose level elevated as a diabetic model), the glucose-lowering effect of GCGR mAb was attenuated and the plasma insulin level, β-cell area, and β-cell dedifferentiation were not affected by GCGR mAb. Our results proved that glucagon induced β-cell dedifferentiation under pathological conditions, and the effect was partially mediated by FoxO1. Our study reveals a novel cross talk between α- and β-cells and is helpful to understand the pathophysiology of diabetes and discover new targets for diabetes treatment.NEW & NOTEWORTHY Glucagon-secreting pancreatic α-cells can interact with β-cells. However, the long-term effect of glucagon on the function and phenotype of β-cells has remained elusive. Our new finding shows that long-term glucagon induces β-cell dedifferentiation in cultured β-cells. FoxO1 inhibitor mimicks whereas glucagon signaling blockage by GCGR mAb reverses the effect of glucagon. In type 2 diabetic mice, GCGR mAb increases β-cell area, improves β-cell function, and inhibits β-cell dedifferentiation, and the effect is partially mediated by FoxO1.
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Affiliation(s)
- Kangli Wang
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Xiaona Cui
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Fei Li
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Li Xia
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Tianjiao Wei
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Junling Liu
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Wei Fu
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Jin Yang
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| | - Tianpei Hong
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| | - Rui Wei
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
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16
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Zimmermann T, Thomas L, Baader-Pagler T, Haebel P, Simon E, Reindl W, Bajrami B, Rist W, Uphues I, Drucker DJ, Klein H, Santhanam R, Hamprecht D, Neubauer H, Augustin R. BI 456906: Discovery and preclinical pharmacology of a novel GCGR/GLP-1R dual agonist with robust anti-obesity efficacy. Mol Metab 2022; 66:101633. [PMID: 36356832 PMCID: PMC9679702 DOI: 10.1016/j.molmet.2022.101633] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/18/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVE Obesity and its associated comorbidities represent a global health challenge with a need for well-tolerated, effective, and mechanistically diverse pharmaceutical interventions. Oxyntomodulin is a gut peptide that activates the glucagon receptor (GCGR) and glucagon-like peptide-1 receptor (GLP-1R) and reduces bodyweight by increasing energy expenditure and reducing energy intake in humans. Here we describe the pharmacological profile of the novel glucagon receptor (GCGR)/GLP-1 receptor (GLP-1R) dual agonist BI 456906. METHODS BI 456906 was characterized using cell-based in vitro assays to determine functional agonism. In vivo pharmacological studies were performed using acute and subchronic dosing regimens to demonstrate target engagement for the GCGR and GLP-1R, and weight lowering efficacy. RESULTS BI 456906 is a potent, acylated peptide containing a C18 fatty acid as a half-life extending principle to support once-weekly dosing in humans. Pharmacological doses of BI 456906 provided greater bodyweight reductions in mice compared with maximally effective doses of the GLP-1R agonist semaglutide. BI 456906's superior efficacy is the consequence of increased energy expenditure and reduced food intake. Engagement of both receptors in vivo was demonstrated via glucose tolerance, food intake, and gastric emptying tests for the GLP-1R, and liver nicotinamide N-methyltransferase mRNA expression and circulating biomarkers (amino acids, fibroblast growth factor-21) for the GCGR. The dual activity of BI 456906 at the GLP-1R and GCGR was supported using GLP-1R knockout and transgenic reporter mice, and an ex vivo bioactivity assay. CONCLUSIONS BI 456906 is a potent GCGR/GLP-1R dual agonist with robust anti-obesity efficacy achieved by increasing energy expenditure and decreasing food intake.
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Affiliation(s)
- Tina Zimmermann
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Leo Thomas
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Tamara Baader-Pagler
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Peter Haebel
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Eric Simon
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Wolfgang Reindl
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Besnik Bajrami
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Wolfgang Rist
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Ingo Uphues
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Daniel J Drucker
- Lunenfeld-Tanenbaum Research Institute, University of Toronto, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada.
| | - Holger Klein
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Rakesh Santhanam
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Dieter Hamprecht
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany; Boehringer Ingelheim Research Italia, Via Lorenzini 8, 20139 Milano, Italy.
| | - Heike Neubauer
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
| | - Robert Augustin
- Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Str. 65, 88400 Biberach an der Riβ, Germany.
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17
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Hope DCD, Hinds CE, Lopes T, Vincent ML, Shrewsbury JV, Yu ATC, Davies I, Scott R, Jones B, Murphy KG, Minnion JS, Sardini A, Carling D, Lutz TA, Bloom SR, Tan TMM, Owen BM. Hypoaminoacidemia underpins glucagon-mediated energy expenditure and weight loss. Cell Rep Med 2022; 3:100810. [PMID: 36384093 PMCID: PMC9729826 DOI: 10.1016/j.xcrm.2022.100810] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 09/26/2022] [Accepted: 10/13/2022] [Indexed: 11/17/2022]
Abstract
Glucagon analogs show promise as components of next-generation, multi-target, anti-obesity therapeutics. The biology of chronic glucagon treatment, in particular, its ability to induce energy expenditure and weight loss, remains poorly understood. Using a long-acting glucagon analog, G108, we demonstrate that glucagon-mediated body weight loss is intrinsically linked to the hypoaminoacidemia associated with its known amino acid catabolic action. Mechanistic studies reveal an energy-consuming response to low plasma amino acids in G108-treated mice, prevented by dietary amino acid supplementation and mimicked by a rationally designed low amino acid diet. Therefore, low plasma amino acids are a pre-requisite for G108-mediated energy expenditure and weight loss. However, preventing hypoaminoacidemia with additional dietary protein does not affect the ability of G108 to improve glycemia or hepatic steatosis in obese mice. These studies provide a mechanism for glucagon-mediated weight loss and confirm the hepatic glucagon receptor as an attractive molecular target for metabolic disease therapeutics.
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Affiliation(s)
- David C D Hope
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Charlotte E Hinds
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Tatiana Lopes
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Matthew L Vincent
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Jed V Shrewsbury
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Arthur T C Yu
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Iona Davies
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Rebecca Scott
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Ben Jones
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Kevin G Murphy
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - James S Minnion
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Alessandro Sardini
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - David Carling
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - Thomas A Lutz
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Stephen R Bloom
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Tricia M M Tan
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.
| | - Bryn M Owen
- Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.
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18
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Kang Q, Zheng J, Jia J, Xu Y, Bai X, Chen X, Zhang XK, Wong FS, Zhang C, Li M. Disruption of the glucagon receptor increases glucagon expression beyond α-cell hyperplasia in zebrafish. J Biol Chem 2022; 298:102665. [PMID: 36334626 PMCID: PMC9719020 DOI: 10.1016/j.jbc.2022.102665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/11/2022] Open
Abstract
The glucagon receptor (GCGR) is a potential target for diabetes therapy. Several emerging GCGR antagonism-based therapies are under preclinical and clinical development. However, GCGR antagonism, as well as genetically engineered GCGR deficiency in animal models, are accompanied by α-cell hyperplasia and hyperglucagonemia, which may limit the application of GCGR antagonism. To better understand the physiological changes in α cells following GCGR disruption, we performed single cell sequencing of α cells isolated from control and gcgr-/- (glucagon receptor deficient) zebrafish. Interestingly, beyond the α-cell hyperplasia, we also found that the expression of gcga, gcgb, pnoca, and several glucagon-regulatory transcription factors were dramatically increased in one cluster of gcgr-/- α cells. We further confirmed that glucagon mRNA was upregulated in gcgr-/- animals by in situ hybridization and that glucagon promoter activity was increased in gcgr-/-;Tg(gcga:GFP) reporter zebrafish. We also demonstrated that gcgr-/- α cells had increased glucagon protein levels and increased granules after GCGR disruption. Intriguingly, the increased mRNA and protein levels could be suppressed by treatment with high-level glucose or knockdown of the pnoca gene. In conclusion, these data demonstrated that GCGR deficiency not only induced α-cell hyperplasia but also increased glucagon expression in α cells, findings which provide more information about physiological changes in α-cells when the GCGR is disrupted.
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Affiliation(s)
- Qi Kang
- School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, China
| | - Jihong Zheng
- Fundamental Research Center, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jianxin Jia
- School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, China
| | - Ying Xu
- Fundamental Research Center, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xuanxuan Bai
- School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen, China; Fundamental Research Center, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xinhua Chen
- Key Laboratory of Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiao-Kun Zhang
- School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, China
| | - F Susan Wong
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, UK
| | - Chao Zhang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Mingyu Li
- School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, China.
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19
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Capozzi ME, D'Alessio DA, Campbell JE. The past, present, and future physiology and pharmacology of glucagon. Cell Metab 2022; 34:1654-1674. [PMID: 36323234 PMCID: PMC9641554 DOI: 10.1016/j.cmet.2022.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/23/2022] [Accepted: 09/30/2022] [Indexed: 11/07/2022]
Abstract
The evolution of glucagon has seen the transition from an impurity in the preparation of insulin to the development of glucagon receptor agonists for use in type 1 diabetes. In type 2 diabetes, glucagon receptor antagonists have been explored to reduce glycemia thought to be induced by hyperglucagonemia. However, the catabolic actions of glucagon are currently being leveraged to target the rise in obesity that paralleled that of diabetes, bringing the pharmacology of glucagon full circle. During this evolution, the physiological importance of glucagon advanced beyond the control of hepatic glucose production, incorporating critical roles for glucagon to regulate both lipid and amino acid metabolism. Thus, it is unsurprising that the study of glucagon has left several paradoxes that make it difficult to distill this hormone down to a simplified action. Here, we describe the history of glucagon from the past to the present and suggest some direction to the future of this field.
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Affiliation(s)
- Megan E Capozzi
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA
| | - David A D'Alessio
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Endocrinology Division, Duke University Medical Center, Durham, NC 27701, USA
| | - Jonathan E Campbell
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Endocrinology Division, Duke University Medical Center, Durham, NC 27701, USA; Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27701, USA.
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20
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Kim T, Nason S, Antipenko J, Finan B, Shalev A, DiMarchi R, Habegger KM. Hepatic mTORC2 Signaling Facilitates Acute Glucagon Receptor Enhancement of Insulin-Stimulated Glucose Homeostasis in Mice. Diabetes 2022; 71:2123-2135. [PMID: 35877180 PMCID: PMC9501720 DOI: 10.2337/db21-1018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 07/21/2022] [Indexed: 11/13/2022]
Abstract
Long-term glucagon receptor (GCGR) agonism is associated with hyperglycemia and glucose intolerance, while acute GCGR agonism enhances whole-body insulin sensitivity and hepatic AKTSer473 phosphorylation. These divergent effects establish a critical gap in knowledge surrounding GCGR action. mTOR complex 2 (mTORC2) is composed of seven proteins, including RICTOR, which dictates substrate binding and allows for targeting of AKTSer473. We used a liver-specific Rictor knockout mouse (RictorΔLiver) to investigate whether mTORC2 is necessary for insulin receptor (INSR) and GCGR cross talk. RictorΔLiver mice were characterized by impaired AKT signaling and glucose intolerance. Intriguingly, RictorΔLiver mice were also resistant to GCGR-stimulated hyperglycemia. Consistent with our prior report, GCGR agonism increased glucose infusion rate and suppressed hepatic glucose production during hyperinsulinemic-euglycemic clamp of control animals. However, these benefits to insulin sensitivity were ablated in RictorΔLiver mice. We observed diminished AKTSer473 and GSK3α/βSer21/9 phosphorylation in RictorΔLiver mice, whereas phosphorylation of AKTThr308 was unaltered in livers from clamped mice. These signaling effects were replicated in primary hepatocytes isolated from RictorΔLiver and littermate control mice, confirming cell-autonomous cross talk between GCGR and INSR pathways. In summary, our study reveals the necessity of RICTOR, and thus mTORC2, in GCGR-mediated enhancement of liver and whole-body insulin action.
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Affiliation(s)
- Teayoun Kim
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Shelly Nason
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Jessica Antipenko
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Brian Finan
- Novo Nordisk Research Center Indianapolis, Indianapolis, IN
| | - Anath Shalev
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | | | - Kirk M. Habegger
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
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21
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Abstract
Although the physiological role of glucagon receptor signaling in the liver is well defined, the impact of glucagon receptor (Gcgr) signaling on white adipose tissue (WAT) continues to be debated. Although numerous studies propose that glucagon stimulates WAT lipolysis, we lack evidence that physiological concentrations of glucagon regulate WAT lipolysis. In turn, we performed studies in both wild-type and WAT Gcgr knockout mice to determine if glucagon regulates lipolysis at WAT in the mouse. We assessed the effects of fasting and acute exogenous glucagon administration in wild-type C57BL/6J and GcgrAdipocyte+/+ versus GcgrAdipocyte-/- mice. Using an ex vivo lipolysis protocol, we further examined the direct effects of glucagon on physiologically (fasted) and pharmacologically stimulated lipolysis. We found that adipocyte Gcgr expression did not affect fasting-induced lipolysis or hepatic lipid accumulation in lean or diet-induced obese (DIO) mice. Acute glucagon administration did not affect serum nonesterified fatty acids (NEFA), leptin, or adiponectin concentration, but did increase serum glucose and FGF21, regardless of genotype. Glucagon did not affect ex vivo lipolysis in explants from either GcgrAdipocyte+/+ or GcgrAdipocyte-/- mice. Gcgr expression did not affect fasting-induced or isoproterenol-stimulated lipolysis from WAT explants. Moreover, glucagon receptor signaling at WAT did not affect body weight or glucose homeostasis in lean or DIO mice. Our studies have established that physiological levels of glucagon do not regulate WAT lipolysis, either directly or indirectly. Given that glucagon receptor agonism can improve dyslipidemia and decrease hepatic lipid accumulation, it is critical to understand the tissue-specific effects of glucagon receptor action. Unlike the crucial role of hepatic glucagon receptor signaling in maintaining glucose and lipid homeostasis, we observed no metabolic consequence of WAT glucagon receptor deletion.NEW & NOTEWORTHY It has been postulated that glucagon stimulates lipolysis and fatty acid release from white adipose tissue. We observed no metabolic effects of eliminating or activating glucagon receptor signaling at white adipose tissue.
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Affiliation(s)
- Anastasiia Vasileva
- Division of Endocrinology, University of Arizona College of Medicine, Tucson, Arizona
| | - Tyler Marx
- Division of Endocrinology, University of Arizona College of Medicine, Tucson, Arizona
| | - Jacqueline L Beaudry
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Jennifer H Stern
- Division of Endocrinology, University of Arizona College of Medicine, Tucson, Arizona
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22
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Habegger KM. Cross Talk Between Insulin and Glucagon Receptor Signaling in the Hepatocyte. Diabetes 2022; 71:1842-1851. [PMID: 35657690 PMCID: PMC9450567 DOI: 10.2337/dbi22-0002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/19/2022] [Indexed: 11/13/2022]
Abstract
While the consumption of external energy (i.e., feeding) is essential to life, this action induces a temporary disturbance of homeostasis in an animal. A primary example of this effect is found in the regulation of glycemia. In the fasted state, stored energy is released to maintain physiological glycemic levels. Liver glycogen is liberated to glucose, glycerol and (glucogenic) amino acids are used to build new glucose molecules (i.e., gluconeogenesis), and fatty acids are oxidized to fuel long-term energetic demands. This regulation is driven primarily by the counterregulatory hormones epinephrine, growth hormone, cortisol, and glucagon. Conversely, feeding induces a rapid influx of diverse nutrients, including glucose, that disrupt homeostasis. Consistently, a host of hormonal and neural systems under the coordination of insulin are engaged in the transition from fasting to prandial states to reduce this disruption. The ultimate action of these systems is to appropriately store the newly acquired energy and to return to the homeostatic norm. Thus, at first glance it is tempting to assume that glucagon is solely antagonistic regarding the anabolic effects of insulin. We have been intrigued by the role of glucagon in the prandial transition and have attempted to delineate its role as beneficial or inhibitory to glycemic control. The following review highlights this long-known yet poorly understood hormone.
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Affiliation(s)
- Kirk M. Habegger
- Comprehensive Diabetes Center and Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
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23
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McGlone ER, Ansell TB, Dunsterville C, Song W, Carling D, Tomas A, Bloom SR, Sansom MSP, Tan T, Jones B. Hepatocyte cholesterol content modulates glucagon receptor signalling. Mol Metab 2022; 63:101530. [PMID: 35718339 PMCID: PMC9254120 DOI: 10.1016/j.molmet.2022.101530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 06/13/2022] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To determine whether glucagon receptor (GCGR) actions are modulated by cellular cholesterol levels. METHODS We determined the effects of experimental cholesterol depletion and loading on glucagon-mediated cAMP production, ligand internalisation and glucose production in human hepatoma cells, mouse and human hepatocytes. GCGR interactions with lipid bilayers were explored using coarse-grained molecular dynamic simulations. Glucagon responsiveness was measured in mice fed a high cholesterol diet with or without simvastatin to modulate hepatocyte cholesterol content. RESULTS GCGR cAMP signalling was reduced by higher cholesterol levels across different cellular models. Ex vivo glucagon-induced glucose output from mouse hepatocytes was enhanced by simvastatin treatment. Mice fed a high cholesterol diet had increased hepatic cholesterol and a blunted hyperglycaemic response to glucagon, both of which were partially reversed by simvastatin. Simulations identified likely membrane-exposed cholesterol binding sites on the GCGR, including a site where cholesterol is a putative negative allosteric modulator. CONCLUSIONS Our results indicate that cellular cholesterol content influences glucagon sensitivity and indicate a potential molecular basis for this phenomenon. This could be relevant to the pathogenesis of non-alcoholic fatty liver disease, which is associated with both hepatic cholesterol accumulation and glucagon resistance.
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Affiliation(s)
- Emma Rose McGlone
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London W12 0NN, United Kingdom; Department of Surgery and Cancer, Imperial College London, London W12 0NN, United Kingdom.
| | - T Bertie Ansell
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.
| | - Cecilia Dunsterville
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London W12 0NN, United Kingdom.
| | - Wanling Song
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.
| | - David Carling
- Cellular Stress Research Group, MRC London Institute of Medical Sciences, Imperial College London, London W12 0NN, United Kingdom.
| | - Alejandra Tomas
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London W12 0NN, United Kingdom.
| | - Stephen R Bloom
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London W12 0NN, United Kingdom.
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.
| | - Tricia Tan
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London W12 0NN, United Kingdom.
| | - Ben Jones
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London W12 0NN, United Kingdom.
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24
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Li L, Dai S, Liu JY, Wu W, Zhao QX, Wang X, Wang N, Xu ZH. Antagonistic Effect and In Vitro Activity of Dauricine on Glucagon Receptor. J Nat Prod 2022; 85:2035-2043. [PMID: 35834753 DOI: 10.1021/acs.jnatprod.2c00446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Abnormal increases in glucagon (GCG) are the primary cause of type II diabetes mellitus. When GCG interacts with a glucagon receptor (GCGR), GCG can increase the blood glucose level. In this paper, a compound that could interfere with the binding of GCG and GCGR to inhibit the increase of blood glucose was investigated. First, molecular docking was used to conduct preliminary screening of compounds whose active components could combine with GCGR by AutoDock Vina. The binding of the receptor-ligand complex was analyzed by PyMOL. Results showed that dauricine could tightly bind to the receptor pocket. Second, the plasmid pcDNA3.1(+)-GCGR containing the target gene was transfected into HEK293 cells for expression, which was the cell model established to screen GCGR antagonist. Dauricine, the lead compound of glucagon receptor antagonist (GRA), was screened using the GRA screening model in vitro. Finally, using [Des-His1, Glu9]-Glucagon amide as the positive control, flow cytometry was used to express the antagonistic effect of the compound. Consequently, dauricine can antagonize the GCGR.
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Affiliation(s)
- Li Li
- College of Science, Xihua University, Chengdu 610039, China
| | - Shuang Dai
- College of Science, Xihua University, Chengdu 610039, China
| | - Jing-Ya Liu
- College of Science, Xihua University, Chengdu 610039, China
| | - Wei Wu
- College of Science, Xihua University, Chengdu 610039, China
| | - Qian-Xi Zhao
- College of Science, Xihua University, Chengdu 610039, China
| | - Xin Wang
- College of Science, Xihua University, Chengdu 610039, China
| | - Na Wang
- College of Science, Xihua University, Chengdu 610039, China
| | - Zhi-Hong Xu
- College of Science, Xihua University, Chengdu 610039, China
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25
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Qiao L, Saget S, Lu C, Zang T, Dzyuba B, Hay WW, Shao J. The Essential Role of Pancreatic α-Cells in Maternal Metabolic Adaptation to Pregnancy. Diabetes 2022; 71:978-988. [PMID: 35147704 PMCID: PMC9044124 DOI: 10.2337/db21-0923] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022]
Abstract
Pancreatic α-cells are important in maintaining metabolic homeostasis, but their role in regulating maternal metabolic adaptations to pregnancy has not been studied. The objective of this study was to determine whether pancreatic α-cells respond to pregnancy and their contribution to maternal metabolic adaptation. With use of C57BL/6 mice, the findings of our study showed that pregnancy induced a significant increase of α-cell mass by promoting α-cell proliferation that was associated with a transitory increase of maternal serum glucagon concentration in early pregnancy. Maternal pancreatic GLP-1 content also was significantly increased during pregnancy. Using the inducible Cre/loxp technique, we ablated the α-cells (α-null) before and during pregnancy while maintaining enteroendocrine L-cells and serum GLP-1 in the normal range. In contrast to an improved glucose tolerance test (GTT) before pregnancy, significantly impaired GTT and remarkably higher serum glucose concentrations in the fed state were observed in α-null dams. Glucagon receptor antagonism treatment, however, did not affect measures of maternal glucose metabolism, indicating a dispensable role of glucagon receptor signaling in maternal glucose homeostasis. However, the GLP-1 receptor agonist improved insulin production and glucose metabolism of α-null dams. Furthermore, GLP-1 receptor antagonist Exendin (9-39) attenuated pregnancy-enhanced insulin secretion and GLP-1 restored glucose-induced insulin secretion of cultured islets from α-null dams. Together, these results demonstrate that α-cells play an essential role in controlling maternal metabolic adaptation to pregnancy by enhancing insulin secretion.
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Affiliation(s)
- Liping Qiao
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Sarah Saget
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Cindy Lu
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Tianyi Zang
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Brianna Dzyuba
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | | | - Jianhua Shao
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
- Corresponding author: Jianhua Shao,
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26
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Simonsen L, Lau J, Kruse T, Guo T, McGuire J, Jeppesen JF, Niss K, Sauerberg P, Raun K, Dornonville de la Cour C. Preclinical evaluation of a protracted GLP-1/glucagon receptor co-agonist: Translational difficulties and pitfalls. PLoS One 2022; 17:e0264974. [PMID: 35245328 PMCID: PMC8896685 DOI: 10.1371/journal.pone.0264974] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 02/19/2022] [Indexed: 12/13/2022] Open
Abstract
During recent years combining GLP-1 and glucagon receptor agonism with the purpose of achieving superior weight loss and metabolic control compared to GLP-1 alone has received much attention. The superior efficacy has been shown by several in preclinical models but has been difficult to reproduce in humans. In this paper, we present the pre-clinical evaluation of NN1177, a long-acting GLP-1/glucagon receptor co-agonist previously tested in clinical trials. To further investigate the contribution from the respective receptors, two other co-agonists (NN1151, NN1359) with different GLP-1-to-glucagon receptor ratios were evaluated in parallel. In the process of characterizing NN1177, species differences and pitfalls in traditional pre-clinical evaluation methods were identified, highlighting the translational challenges in predicting the optimal receptor balance in humans. In diet-induced obese (DIO) mice, NN1177 induced a dose-dependent body weight loss, primarily due to loss of fat mass, and improvement in glucose tolerance. In DIO rats, NN1177 induced a comparable total body weight reduction, which was in contrast mainly caused by loss of lean mass, and glucose tolerance was impaired. Furthermore, despite long half-lives of the three co-agonists, glucose control during steady state was seen to depend on compound exposure at time of evaluation. When evaluated at higher compound exposure, glucose tolerance was similarly improved for all three co-agonists, independent of receptor balance. However, at lower compound exposure, glucose tolerance was gradually impaired with higher glucagon receptor preference. In addition, glucose tolerance was found to depend on study duration where the effect of glucagon on glucose control became more evident with time. To conclude, the pharmacodynamic effects at a given GLP-1-to-glucagon ratio differs between species, depends on compound exposure and study length, complicating the identification of an optimally balanced clinical candidate. The present findings could partly explain the low number of clinical successes for this dual agonism.
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Affiliation(s)
- Lotte Simonsen
- Global Obesity & Liver Disease Research, Novo Nordisk A/S, Måløv, Denmark
| | - Jesper Lau
- Research Chemistry, Novo Nordisk A/S, Måløv, Denmark
| | - Thomas Kruse
- Research Chemistry, Novo Nordisk A/S, Måløv, Denmark
| | - Tingqing Guo
- Discovery Biology, Novo Nordisk Research Centre, Beijing, China
| | - Jim McGuire
- Incretin Biology, Novo Nordisk A/S, Måløv, Denmark
| | | | - Kristoffer Niss
- Bioinformatics & Data Mining, Novo Nordisk A/S, Måløv, Denmark
| | - Per Sauerberg
- Project and Alliance Management, Novo Nordisk A/S, Måløv, Denmark
| | - Kirsten Raun
- Global Obesity & Liver Disease Research, Novo Nordisk A/S, Måløv, Denmark
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27
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Conceição-Furber E, Coskun T, Sloop KW, Samms RJ. Is Glucagon Receptor Activation the Thermogenic Solution for Treating Obesity? Front Endocrinol (Lausanne) 2022; 13:868037. [PMID: 35547006 PMCID: PMC9081793 DOI: 10.3389/fendo.2022.868037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 03/07/2022] [Indexed: 12/19/2022] Open
Abstract
A major challenge of obesity therapy is to sustain clinically relevant weight loss over time. Achieving this goal likely requires both reducing daily caloric intake and increasing caloric expenditure. Over the past decade, advances in pharmaceutical engineering of ligands targeting G protein-coupled receptors have led to the development of highly effective anorectic agents. These include mono-agonists of the GLP-1R and dual GIPR/GLP-1R co-agonists that have demonstrated substantial weight loss in experimental models and in humans. By contrast, currently, there are no medicines available that effectively augment metabolic rate to promote weight loss. Here, we present evidence indicating that activation of the GCGR may provide a solution to this unmet therapeutic need. In adult humans, GCGR agonism increases energy expenditure to a magnitude sufficient for inducing a negative energy balance. In preclinical studies, the glucagon-GCGR system affects key metabolically relevant organs (including the liver and white and brown adipose tissue) to boost whole-body thermogenic capacity and protect from obesity. Further, activation of the GCGR has been shown to augment both the magnitude and duration of weight loss that is achieved by either selective GLP-1R or dual GIPR/GLP-1R agonism in rodents. Based on the accumulation of such findings, we propose that the thermogenic activity of GCGR agonism will also complement other anti-obesity agents that lower body weight by suppressing appetite.
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28
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Park BG, Kim GM, Lee HJ, Ryu JH, Kim DH, Seong JY, Kim S, Park ZY, Kim YJ, Lee J, Kim JI. Antiobesity therapeutics with complementary dual-agonist activities at glucagon and glucagon-like peptide 1 receptors. Diabetes Obes Metab 2022; 24:50-60. [PMID: 34491605 DOI: 10.1111/dom.14546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 08/17/2021] [Accepted: 09/01/2021] [Indexed: 12/21/2022]
Abstract
AIM To develop more effective and long-lasting antiobesity and antidiabetic therapeutics by employing novel chemical modifications of glucagon-like peptide-1 receptor (GLP-1R) agonists. METHODS We constructed novel unimolecular dual agonists of GLP-1R and glucagon receptor prepared by linking sEx-4 and native glucagon (GCG) via lysine or triazole [sEx4-GCG(K) and sEx4-GCG(T), respectively] and evaluated their antiobesity and antidiabetic efficacy in the diabetic and obese mouse model. RESULTS Both sEx4-GCG(K) and sEx4-GCG(T) showed the beneficial metabolic effects of GLP-1 and glucagon: they promoted weight loss and ameliorated insulin resistance and hepatic steatosis. They also increased thermogenesis in brown adipose tissue, and lipolysis and β-oxidation in white adipose tissue, with concomitant suppression of lipogenesis. Furthermore, both dual agonists activated the 5'-AMP-activated protein kinase signalling pathway and prevented palmitate-induced oxidative stress in skeletal muscle cells. CONCLUSION Through their complementary dual agonism, sEx4-GCG(T) and sEx4-GCG(K) induce more marked weight loss and metabolic improvements than conventional agonists, and could be developed as novel therapeutic agents for the treatment of obesity and associated metabolic disorders in humans.
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Affiliation(s)
- Bong Gyu Park
- Department of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Gyeong Min Kim
- Department of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Hye-Jin Lee
- Department of Pharmacology, Korea University College of Medicine, Seoul, Republic of Korea
| | - Jae Ha Ryu
- Pilot Plant, Anygen, Gwangju, Republic of Korea
| | - Dong-Hoon Kim
- Department of Pharmacology, Korea University College of Medicine, Seoul, Republic of Korea
| | - Jae-Young Seong
- Graduate School of Medicine, Korea University, Seoul, Republic of Korea
| | - Soojeong Kim
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Zee-Yong Park
- Department of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Young-Joon Kim
- Department of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
| | - Jaemin Lee
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Jae Il Kim
- Department of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea
- Pilot Plant, Anygen, Gwangju, Republic of Korea
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Hinds CE, Owen BM, Hope DCD, Pickford P, Jones B, Tan TM, Minnion JS, Bloom SR. A glucagon analogue decreases body weight in mice via signalling in the liver. Sci Rep 2021; 11:22577. [PMID: 34799628 PMCID: PMC8604983 DOI: 10.1038/s41598-021-01912-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 10/26/2021] [Indexed: 12/30/2022] Open
Abstract
Glucagon receptor agonists show promise as components of next generation metabolic syndrome pharmacotherapies. However, the biology of glucagon action is complex, controversial, and likely context dependent. As such, a better understanding of chronic glucagon receptor (GCGR) agonism is essential to identify and mitigate potential clinical side-effects. Herein we present a novel, long-acting glucagon analogue (GCG104) with high receptor-specificity and potent in vivo action. It has allowed us to make two important observations about the biology of sustained GCGR agonism. First, it causes weight loss in mice by direct receptor signalling at the level of the liver. Second, subtle changes in GCG104-sensitivity, possibly due to interindividual variation, may be sufficient to alter its effects on metabolic parameters. Together, these findings confirm the liver as a principal target for glucagon-mediated weight loss and provide new insights into the biology of glucagon analogues.
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Affiliation(s)
- Charlotte E Hinds
- Section of Investigative Medicine, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, W12 0NN, UK
| | - Bryn M Owen
- Section of Investigative Medicine, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, W12 0NN, UK
| | - David C D Hope
- Section of Investigative Medicine, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, W12 0NN, UK
| | - Philip Pickford
- Section of Investigative Medicine, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, W12 0NN, UK
| | - Ben Jones
- Section of Investigative Medicine, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, W12 0NN, UK
| | - Tricia M Tan
- Section of Investigative Medicine, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, W12 0NN, UK
| | - James S Minnion
- Section of Investigative Medicine, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, W12 0NN, UK
| | - Stephen R Bloom
- Section of Investigative Medicine, Department of Metabolism, Digestion, and Reproduction, Imperial College London, London, W12 0NN, UK.
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McGlone ER, Manchanda Y, Jones B, Pickford P, Inoue A, Carling D, Bloom SR, Tan T, Tomas A. Receptor Activity-Modifying Protein 2 (RAMP2) alters glucagon receptor trafficking in hepatocytes with functional effects on receptor signalling. Mol Metab 2021; 53:101296. [PMID: 34271220 PMCID: PMC8363841 DOI: 10.1016/j.molmet.2021.101296] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/01/2021] [Accepted: 07/09/2021] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES Receptor Activity-Modifying Protein 2 (RAMP2) is a chaperone protein which allosterically binds to and interacts with the glucagon receptor (GCGR). The aims of this study were to investigate the effects of RAMP2 on GCGR trafficking and signalling in the liver, where glucagon (GCG) is important for carbohydrate and lipid metabolism. METHODS Subcellular localisation of GCGR in the presence and absence of RAMP2 was investigated using confocal microscopy, trafficking and radioligand binding assays in human embryonic kidney (HEK293T) and human hepatoma (Huh7) cells. Mouse embryonic fibroblasts (MEFs) lacking the Wiskott-Aldrich Syndrome protein and scar homologue (WASH) complex and the trafficking inhibitor monensin were used to investigate the effect of halted recycling of internalised proteins on GCGR subcellular localisation and signalling in the absence of RAMP2. NanoBiT complementation and cyclic AMP assays were used to study the functional effect of RAMP2 on the recruitment and activation of GCGR signalling mediators. Response to hepatic RAMP2 upregulation in lean and obese adult mice using a bespoke adeno-associated viral vector was also studied. RESULTS GCGR is predominantly localised at the plasma membrane in the absence of RAMP2 and exhibits remarkably slow internalisation in response to agonist stimulation. Rapid intracellular accumulation of GCG-stimulated GCGR in cells lacking the WASH complex or in the presence of monensin indicates that activated GCGR undergoes continuous cycles of internalisation and recycling, despite apparent GCGR plasma membrane localisation up to 40 min post-stimulation. Co-expression of RAMP2 induces GCGR internalisation both basally and in response to agonist stimulation. The intracellular retention of GCGR in the presence of RAMP2 confers a bias away from β-arrestin-2 recruitment coupled with increased activation of Gαs proteins at endosomes. This is associated with increased short-term efficacy for glucagon-stimulated cAMP production, although long-term signalling is dampened by increased receptor lysosomal targeting for degradation. Despite these signalling effects, only a minor disturbance of carbohydrate metabolism was observed in mice with upregulated hepatic RAMP2. CONCLUSIONS By retaining GCGR intracellularly, RAMP2 alters the spatiotemporal pattern of GCGR signalling. Further exploration of the effects of RAMP2 on GCGR in vivo is warranted.
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Affiliation(s)
- Emma Rose McGlone
- Section of Endocrinology and Investigative Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Yusman Manchanda
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Ben Jones
- Section of Endocrinology and Investigative Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Phil Pickford
- Section of Endocrinology and Investigative Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - David Carling
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - Stephen R Bloom
- Section of Endocrinology and Investigative Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Tricia Tan
- Section of Endocrinology and Investigative Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.
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31
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Liu Q, Lin G, Chen Y, Feng W, Xu Y, Lyu J, Yang D, Wang MW. Deleterious mutation V369M in the mouse GCGR gene causes abnormal plasma amino acid levels indicative of a possible liver-α-cell axis. Biosci Rep 2021; 41:BSR20210758. [PMID: 34002801 PMCID: PMC8173527 DOI: 10.1042/bsr20210758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 01/30/2023] Open
Abstract
Glucagon plays an important role in glucose homeostasis and amino acid metabolism. It regulates plasma amino acid levels which in turn modulate glucagon secretion from the pancreatic α-cell, thereby establishing a liver-α-cell axis described recently. We reported previously that the knock-in mice bearing homozygous V369M substitution (equivalent to a naturally occurring mutation V368M in the human glucagon receptor, GCGR) led to hypoglycemia with improved glucose tolerance. They also exhibited hyperglucagonemia, pancreas enlargement and α-cell hyperplasia. Here, we investigated the effect of V369M/V368M mutation on glucagon-mediated amino acid metabolism. It was found that GcgrV369M+/+ mice displayed increased plasma amino acid levels in general, but significant accumulation of the ketogenic/glucogenic amino acids was observed in animals fed with a high-fat diet (HFD), resulting in deleterious metabolic consequence characteristic of α-cell proliferation and hyperglucagonemia.
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Affiliation(s)
- Qiaofeng Liu
- School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Guangyao Lin
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yan Chen
- School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Wenbo Feng
- School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Yingna Xu
- School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Jianjun Lyu
- Department of Pathology, InnoStar BioTech Nantong Co., Ltd., Nantong 226133, China
| | - Dehua Yang
- The National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences (CAS), Shanghai 201203, China
| | - Ming-Wei Wang
- School of Pharmacy, Fudan University, Shanghai 201203, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- The National Center for Drug Screening and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences (CAS), Shanghai 201203, China
- School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
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32
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Borner T, Workinger JL, Tinsley IC, Fortin SM, Stein LM, Chepurny OG, Holz GG, Wierzba AJ, Gryko D, Nexø E, Shaulson ED, Bamezai A, Da Silva VAR, De Jonghe BC, Hayes MR, Doyle RP. Corrination of a GLP-1 Receptor Agonist for Glycemic Control without Emesis. Cell Rep 2021; 31:107768. [PMID: 32553160 PMCID: PMC7376604 DOI: 10.1016/j.celrep.2020.107768] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 05/10/2019] [Accepted: 05/22/2020] [Indexed: 12/21/2022] Open
Abstract
Glucagon-like peptide-1 receptor (GLP-1R) agonists used to treat type 2 diabetes mellitus often produce nausea, vomiting, and in some patients, undesired anorexia. Notably, these behavioral effects are caused by direct central GLP-1R activation. Herein, we describe the creation of a GLP-1R agonist conjugate with modified brain penetrance that enhances GLP-1R-mediated glycemic control without inducing vomiting. Covalent attachment of the GLP-1R agonist exendin-4 (Ex4) to dicyanocobinamide (Cbi), a corrin ring containing precursor of vitamin B12, produces a "corrinated" Ex4 construct (Cbi-Ex4). Data collected in the musk shrew (Suncus murinus), an emetic mammal, reveal beneficial effects of Cbi-Ex4 relative to Ex4, as evidenced by improvements in glycemic responses in glucose tolerance tests and a profound reduction of emetic events. Our findings highlight the potential for clinical use of Cbi-Ex4 for millions of patients seeking improved glycemic control without common side effects (e.g., emesis) characteristic of current GLP-1 therapeutics.
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Affiliation(s)
- Tito Borner
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Ian C Tinsley
- Department of Chemistry, Syracuse University, Syracuse, NY, USA
| | - Samantha M Fortin
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Lauren M Stein
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Oleg G Chepurny
- Department of Medicine, Upstate Medical University, State University of New York, Syracuse, NY, USA
| | - George G Holz
- Department of Medicine, Upstate Medical University, State University of New York, Syracuse, NY, USA
| | | | - Dorota Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Ebba Nexø
- Department of Clinical Biochemistry and Clinical Medicine, University of Aarhus, Aarhus, Denmark
| | - Evan D Shaulson
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ankur Bamezai
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Valentina A Rodriguez Da Silva
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bart C De Jonghe
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew R Hayes
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert P Doyle
- Department of Chemistry, Syracuse University, Syracuse, NY, USA; Department of Medicine, Upstate Medical University, State University of New York, Syracuse, NY, USA.
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33
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Bozadjieva Kramer N, Lubaczeuski C, Blandino-Rosano M, Barker G, Gittes GK, Caicedo A, Bernal-Mizrachi E. Glucagon Resistance and Decreased Susceptibility to Diabetes in a Model of Chronic Hyperglucagonemia. Diabetes 2021; 70:477-491. [PMID: 33239450 PMCID: PMC7881862 DOI: 10.2337/db20-0440] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 11/18/2020] [Indexed: 02/07/2023]
Abstract
Elevation of glucagon levels and increase in α-cell mass are associated with states of hyperglycemia in diabetes. Our previous studies have highlighted the role of nutrient signaling via mTOR complex 1 (mTORC1) regulation that controls glucagon secretion and α-cell mass. In the current studies we investigated the effects of activation of nutrient signaling by conditional deletion of the mTORC1 inhibitor, TSC2, in α-cells (αTSC2KO). We showed that activation of mTORC1 signaling is sufficient to induce chronic hyperglucagonemia as a result of α-cell proliferation, cell size, and mass expansion. Hyperglucagonemia in αTSC2KO was associated with an increase in glucagon content and enhanced glucagon secretion. This model allowed us to identify the effects of chronic hyperglucagonemia on glucose homeostasis by inducing insulin secretion and resistance to glucagon in the liver. Liver glucagon resistance in αTSC2KO mice was characterized by reduced expression of the glucagon receptor (GCGR), PEPCK, and genes involved in amino acid metabolism and urea production. Glucagon resistance in αTSC2KO mice was associated with improved glucose levels in streptozotocin-induced β-cell destruction and high-fat diet-induced glucose intolerance. These studies demonstrate that chronic hyperglucagonemia can improve glucose homeostasis by inducing glucagon resistance in the liver.
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Affiliation(s)
- Nadejda Bozadjieva Kramer
- Department of Medicine, University of Michigan Medical Center, Ann Arbor, MI
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, MI
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI
| | - Camila Lubaczeuski
- Division of Endocrinology, Metabolism and Diabetes, Department of Internal Medicine, Miller School of Medicine, University of Miami, Miami, FL
| | - Manuel Blandino-Rosano
- Department of Medicine, University of Michigan Medical Center, Ann Arbor, MI
- Division of Endocrinology, Metabolism and Diabetes, Department of Internal Medicine, Miller School of Medicine, University of Miami, Miami, FL
| | - Grant Barker
- Division of Endocrinology, Metabolism and Diabetes, Department of Internal Medicine, Miller School of Medicine, University of Miami, Miami, FL
| | - George K Gittes
- UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburg, PA
| | - Alejandro Caicedo
- Division of Endocrinology, Metabolism and Diabetes, Department of Internal Medicine, Miller School of Medicine, University of Miami, Miami, FL
| | - Ernesto Bernal-Mizrachi
- Division of Endocrinology, Metabolism and Diabetes, Department of Internal Medicine, Miller School of Medicine, University of Miami, Miami, FL
- Veterans Affairs Medical Center, Miami, FL
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34
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Winfield I, Barkan K, Routledge S, Robertson NJ, Harris M, Jazayeri A, Simms J, Reynolds CA, Poyner DR, Ladds G. The Role of ICL1 and H8 in Class B1 GPCRs; Implications for Receptor Activation. Front Endocrinol (Lausanne) 2021; 12:792912. [PMID: 35095763 PMCID: PMC8796428 DOI: 10.3389/fendo.2021.792912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
The first intracellular loop (ICL1) of G protein-coupled receptors (GPCRs) has received little attention, although there is evidence that, with the 8th helix (H8), it is involved in early conformational changes following receptor activation as well as contacting the G protein β subunit. In class B1 GPCRs, the distal part of ICL1 contains a conserved R12.48KLRCxR2.46b motif that extends into the base of the second transmembrane helix; this is weakly conserved as a [R/H]12.48KL[R/H] motif in class A GPCRs. In the current study, the role of ICL1 and H8 in signaling through cAMP, iCa2+ and ERK1/2 has been examined in two class B1 GPCRs, using mutagenesis and molecular dynamics. Mutations throughout ICL1 can either enhance or disrupt cAMP production by CGRP at the CGRP receptor. Alanine mutagenesis identified subtle differences with regard elevation of iCa2+, with the distal end of the loop being particularly sensitive. ERK1/2 activation displayed little sensitivity to ICL1 mutation. A broadly similar pattern was observed with the glucagon receptor, although there were differences in significance of individual residues. Extending the study revealed that at the CRF1 receptor, an insertion in ICL1 switched signaling bias between iCa2+ and cAMP. Molecular dynamics suggested that changes in ICL1 altered the conformation of ICL2 and the H8/TM7 junction (ICL4). For H8, alanine mutagenesis showed the importance of E3908.49b for all three signal transduction pathways, for the CGRP receptor, but mutations of other residues largely just altered ERK1/2 activation. Thus, ICL1 may modulate GPCR bias via interactions with ICL2, ICL4 and the Gβ subunit.
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MESH Headings
- Amino Acid Motifs/physiology
- Calcitonin Receptor-Like Protein/metabolism
- Calcitonin Receptor-Like Protein/physiology
- Calcitonin Receptor-Like Protein/ultrastructure
- Calcium Signaling
- Cyclic AMP/metabolism
- HEK293 Cells
- Humans
- MAP Kinase Signaling System
- Molecular Dynamics Simulation
- Protein Domains
- Protein Structure, Tertiary
- Receptor Activity-Modifying Protein 1/metabolism
- Receptor Activity-Modifying Protein 1/physiology
- Receptor Activity-Modifying Protein 1/ultrastructure
- Receptors, Calcitonin Gene-Related Peptide/metabolism
- Receptors, Calcitonin Gene-Related Peptide/physiology
- Receptors, Calcitonin Gene-Related Peptide/ultrastructure
- Receptors, Corticotropin-Releasing Hormone/metabolism
- Receptors, Corticotropin-Releasing Hormone/physiology
- Receptors, Corticotropin-Releasing Hormone/ultrastructure
- Receptors, G-Protein-Coupled
- Receptors, Glucagon/metabolism
- Receptors, Glucagon/physiology
- Receptors, Glucagon/ultrastructure
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Affiliation(s)
- Ian Winfield
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Kerry Barkan
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Sarah Routledge
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
- School of Life and Health Sciences, Aston University, Birmingham, United Kingdom
| | | | - Matthew Harris
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | | | - John Simms
- School of Life and Health Sciences, Aston University, Birmingham, United Kingdom
| | | | - David R. Poyner
- School of Life and Health Sciences, Aston University, Birmingham, United Kingdom
- *Correspondence: Graham Ladds, ; David R. Poyner,
| | - Graham Ladds
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
- *Correspondence: Graham Ladds, ; David R. Poyner,
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35
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Lee SP, Qi J, Xu G, Rankin MM, Littrell J, Xu JZ, Bakaj I, Pocai A. GRK Inhibition Potentiates Glucagon-Like Peptide-1 Action. Front Endocrinol (Lausanne) 2021; 12:652628. [PMID: 34054727 PMCID: PMC8160450 DOI: 10.3389/fendo.2021.652628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/09/2021] [Indexed: 12/11/2022] Open
Abstract
The glucagon-like peptide-1 receptor (GLP-1R) is a G-protein-coupled receptor (GPCR) whose activation results in suppression of food intake and improvement of glucose metabolism. Several receptor interacting proteins regulate the signaling of GLP-1R such as G protein-coupled receptor kinases (GRK) and β-arrestins. Here we evaluated the physiological and pharmacological impact of GRK inhibition on GLP-1R activity leveraging small molecule inhibitors of GRK2 and GRK3. We demonstrated that inhibition of GRK: i) inhibited GLP-1-mediated β-arrestin recruitment, ii) enhanced GLP-1-induced insulin secretion in isolated islets and iii) has additive effect with dipeptidyl peptidase 4 in mediating suppression of glucose excursion in mice. These findings highlight the importance of GRK to modulate GLP-1R function in vitro and in vivo. GRK inhibition is a potential therapeutic approach to enhance endogenous and pharmacologically stimulated GLP-1R signaling.
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Affiliation(s)
- Seunghun P. Lee
- Cardiovascular and Metabolic Disease Research, Janssen Research & Development, Spring House, PA, United States
| | - Jenson Qi
- Cardiovascular and Metabolic Disease Research, Janssen Research & Development, Spring House, PA, United States
| | - Guozhang Xu
- Discovery Sciences, Janssen Research & Development, Spring House, PA, United States
| | - Matthew M. Rankin
- Cardiovascular and Metabolic Disease Research, Janssen Research & Development, Spring House, PA, United States
| | - James Littrell
- Discovery Sciences, Janssen Research & Development, Spring House, PA, United States
| | - June Zhi Xu
- Cardiovascular and Metabolic Disease Research, Janssen Research & Development, Spring House, PA, United States
| | - Ivona Bakaj
- Cardiovascular and Metabolic Disease Research, Janssen Research & Development, Spring House, PA, United States
| | - Alessandro Pocai
- Cardiovascular and Metabolic Disease Research, Janssen Research & Development, Spring House, PA, United States
- *Correspondence: Alessandro Pocai,
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36
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Kaur S, Chen Y, Shenoy SK. Agonist-activated glucagon receptors are deubiquitinated at early endosomes by two distinct deubiquitinases to facilitate Rab4a-dependent recycling. J Biol Chem 2020; 295:16630-16642. [PMID: 32967969 PMCID: PMC7864061 DOI: 10.1074/jbc.ra120.014532] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 09/17/2020] [Indexed: 01/08/2023] Open
Abstract
The glucagon receptor (GCGR) activated by the peptide hormone glucagon is a seven-transmembrane G protein-coupled receptor (GPCR) that regulates blood glucose levels. Ubiquitination influences trafficking and signaling of many GPCRs, but its characterization for the GCGR is lacking. Using endocytic colocalization and ubiquitination assays, we have identified a correlation between the ubiquitination profile and recycling of the GCGR. Our experiments revealed that GCGRs are constitutively ubiquitinated at the cell surface. Glucagon stimulation not only promoted GCGR endocytic trafficking through Rab5a early endosomes and Rab4a recycling endosomes, but also induced rapid deubiquitination of GCGRs. Inhibiting GCGR internalization or disrupting endocytic trafficking prevented agonist-induced deubiquitination of the GCGR. Furthermore, a Rab4a dominant negative (DN) that blocks trafficking at recycling endosomes enabled GCGR deubiquitination, whereas a Rab5a DN that blocks trafficking at early endosomes eliminated agonist-induced GCGR deubiquitination. By down-regulating candidate deubiquitinases that are either linked with GPCR trafficking or localized on endosomes, we identified signal-transducing adaptor molecule-binding protein (STAMBP) and ubiquitin-specific protease 33 (USP33) as cognate deubiquitinases for the GCGR. Our data suggest that USP33 constitutively deubiquitinates the GCGR, whereas both STAMBP and USP33 deubiquitinate agonist-activated GCGRs at early endosomes. A mutant GCGR with all five intracellular lysines altered to arginines remains deubiquitinated and shows augmented trafficking to Rab4a recycling endosomes compared with the WT, thus affirming the role of deubiquitination in GCGR recycling. We conclude that the GCGRs are rapidly deubiquitinated after agonist-activation to facilitate Rab4a-dependent recycling and that USP33 and STAMBP activities are critical for the endocytic recycling of the GCGR.
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Affiliation(s)
- Suneet Kaur
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Yuqing Chen
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Sudha K Shenoy
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA; Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA.
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37
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Winther-Sørensen M, Galsgaard KD, Santos A, Trammell SAJ, Sulek K, Kuhre RE, Pedersen J, Andersen DB, Hassing AS, Dall M, Treebak JT, Gillum MP, Torekov SS, Windeløv JA, Hunt JE, Kjeldsen SAS, Jepsen SL, Vasilopoulou CG, Knop FK, Ørskov C, Werge MP, Bisgaard HC, Eriksen PL, Vilstrup H, Gluud LL, Holst JJ, Wewer Albrechtsen NJ. Glucagon acutely regulates hepatic amino acid catabolism and the effect may be disturbed by steatosis. Mol Metab 2020; 42:101080. [PMID: 32937194 PMCID: PMC7560169 DOI: 10.1016/j.molmet.2020.101080] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/28/2020] [Accepted: 09/09/2020] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Glucagon is well known to regulate blood glucose but may be equally important for amino acid metabolism. Plasma levels of amino acids are regulated by glucagon-dependent mechanism(s), while amino acids stimulate glucagon secretion from alpha cells, completing the recently described liver-alpha cell axis. The mechanisms underlying the cycle and the possible impact of hepatic steatosis are unclear. METHODS We assessed amino acid clearance in vivo in mice treated with a glucagon receptor antagonist (GRA), transgenic mice with 95% reduction in alpha cells, and mice with hepatic steatosis. In addition, we evaluated urea formation in primary hepatocytes from ob/ob mice and humans, and we studied acute metabolic effects of glucagon in perfused rat livers. We also performed RNA sequencing on livers from glucagon receptor knock-out mice and mice with hepatic steatosis. Finally, we measured individual plasma amino acids and glucagon in healthy controls and in two independent cohorts of patients with biopsy-verified non-alcoholic fatty liver disease (NAFLD). RESULTS Amino acid clearance was reduced in mice treated with GRA and mice lacking endogenous glucagon (loss of alpha cells) concomitantly with reduced production of urea. Glucagon administration markedly changed the secretion of rat liver metabolites and within minutes increased urea formation in mice, in perfused rat liver, and in primary human hepatocytes. Transcriptomic analyses revealed that three genes responsible for amino acid catabolism (Cps1, Slc7a2, and Slc38a2) were downregulated both in mice with hepatic steatosis and in mice with deletion of the glucagon receptor. Cultured ob/ob hepatocytes produced less urea upon stimulation with mixed amino acids, and amino acid clearance was lower in mice with hepatic steatosis. Glucagon-induced ureagenesis was impaired in perfused rat livers with hepatic steatosis. Patients with NAFLD had hyperglucagonemia and increased levels of glucagonotropic amino acids, including alanine in particular. Both glucagon and alanine levels were reduced after diet-induced reduction in Homeostatic Model Assessment for Insulin Resistance (HOMA-IR, a marker of hepatic steatosis). CONCLUSIONS Glucagon regulates amino acid metabolism both non-transcriptionally and transcriptionally. Hepatic steatosis may impair glucagon-dependent enhancement of amino acid catabolism.
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Affiliation(s)
- Marie Winther-Sørensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katrine D Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Alberto Santos
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Samuel A J Trammell
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Karolina Sulek
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rune E Kuhre
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Daniel B Andersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anna S Hassing
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten Dall
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jonas T Treebak
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Matthew P Gillum
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Signe S Torekov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Johanne A Windeløv
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jenna E Hunt
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sasha A S Kjeldsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sara L Jepsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Catherine G Vasilopoulou
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Munich, Germany
| | - Filip K Knop
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Cathrine Ørskov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mikkel P Werge
- Gastrounit, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark
| | - Hanne Cathrine Bisgaard
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Lykke Eriksen
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Hendrik Vilstrup
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Lise Lotte Gluud
- Gastrounit, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department for Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
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Lang S, Wei R, Wei T, Gu L, Feng J, Yan H, Yang J, Hong T. Glucagon receptor antagonism promotes the production of gut proglucagon-derived peptides in diabetic mice. Peptides 2020; 131:170349. [PMID: 32561493 DOI: 10.1016/j.peptides.2020.170349] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 06/14/2020] [Accepted: 06/15/2020] [Indexed: 12/23/2022]
Abstract
Glucagon is an essential regulator of glucose homeostasis, particularly in type 2 diabetes (T2D). Blocking the glucagon receptor (GCGR) in diabetic animals and humans has been shown to alleviate hyperglycemia and increase circulating glucagon-like peptide-1 (GLP-1) levels. However, the origin of the upregulated GLP-1 remains to be clarified. Here, we administered high-fat diet + streptozotocin-induced T2D mice and diabetic db/db mice with REMD 2.59, a fully competitive antagonistic human GCGR monoclonal antibody (mAb) for 12 weeks. GCGR mAb treatment decreased fasting blood glucose levels and increased plasma GLP-1 levels in the T2D mice. In addition, GCGR mAb upregulated preproglucagon gene expression and the contents of gut proglucagon-derived peptides, particularly GLP-1, in the small intestine and colon. Notably, T2D mice treated with GCGR mAb displayed a higher L-cell density in the small intestine and colon, which was associated with increased numbers of LK-cells coexpressing GLP-1 and glucose-dependent insulinotropic polypeptide and reduced L-cell apoptosis. Furthermore, GCGR mAb treatment upregulated GLP-1 production in the pancreas, which was detected at lower levels than in the intestine. Collectively, these results suggest that GCGR mAb can increase intestinal GLP-1 production and L-cell number by enhancing LK-cell expansion and inhibiting L-cell apoptosis in T2D.
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MESH Headings
- Animals
- Antibodies, Monoclonal/pharmacology
- Antibodies, Neutralizing/pharmacology
- Apoptosis/genetics
- Blood Glucose/metabolism
- Colon/drug effects
- Colon/metabolism
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/etiology
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diet, High-Fat/adverse effects
- Fasting/metabolism
- Gastric Inhibitory Polypeptide/genetics
- Gastric Inhibitory Polypeptide/metabolism
- Gene Expression Regulation
- Glucagon-Like Peptide 1/genetics
- Glucagon-Like Peptide 1/metabolism
- Humans
- Intestine, Small/drug effects
- Intestine, Small/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Pancreas/drug effects
- Pancreas/metabolism
- Proglucagon/genetics
- Proglucagon/metabolism
- Receptors, Glucagon/antagonists & inhibitors
- Receptors, Glucagon/genetics
- Receptors, Glucagon/metabolism
- Signal Transduction
- Streptozocin/administration & dosage
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Affiliation(s)
- Shan Lang
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing 100191, China; Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing 100191, China
| | - Rui Wei
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing 100191, China; Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing 100191, China
| | - Tianjiao Wei
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing 100191, China; Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing 100191, China
| | - Liangbiao Gu
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing 100191, China
| | - Jin Feng
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing 100191, China
| | - Hai Yan
- REMD Biotherapeutics, Camarillo, CA 93012, USA; Beijing Cosci-REMD, Beijing 102206, China
| | - Jin Yang
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing 100191, China.
| | - Tianpei Hong
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing 100191, China; Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing 100191, China.
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Abstract
Obesity is a chronic recurring disease whose prevalence has almost tripled over the past 40 years. In individuals with obesity, there is significant increased risk of morbidity and mortality, along with decreased quality of life. Increased obesity prevalence results, at least partly, from the increased global food supply that provides ubiquitous access to tasty, energy-dense foods. These hedonic foods and the nonfood cues that through association become reward predictive cues activate brain appetitive control circuits that drive hyperphagia and weight gain by enhancing food-seeking, motivation, and reward. Behavioral therapy (diet and lifestyle modifications) is the recommended initial treatment for obesity, yet it often fails to achieve meaningful weight loss. Furthermore, those who lose weight regain it over time through biological regulation. The need to effectively treat the pathophysiology of obesity thus centers on biologically based approaches such as bariatric surgery and more recently developed drug therapies. This review highlights neurobiological aspects relevant to obesity causation and treatment by emphasizing the common aspects of the feeding-inhibitory effects of multiple signals. We focus on glucagon like peptide-1 receptor (GLP-1R) signaling as a promising obesity treatment target by discussing the activation of intestinal- and brain-derived GLP-1 and GLP-1R expressing central nervous system circuits resulting from normal eating, bariatric surgery, and GLP-1R agonist drug therapy. Given the increased availability of energy-dense foods and frequent encounters with cues that drive hyperphagia, this review also describes how bariatric surgery and GLP-1R agonist therapies influence food reward and the motivational drive to overeat.
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Affiliation(s)
- Harvey J Grill
- Institute of Diabetes, Obesity and Metabolism, Graduate Groups for Psychology and Neuroscience, University of Pennsylvania, Philadelphia, PA
- Correspondence: Harvey J. Grill, Institute of Diabetes, Obesity and Metabolism, Graduate Groups fo Psychology and Neuroscience, University of Pennsylvania, Philadelphia, PA 19104. E-mail:
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40
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Abstract
We report on a combined activation mechanism for a class B G-protein-coupled receptor (GPCR), the glucagon receptor. By computing the conformational free-energy landscape associated with the activation of the receptor-agonist complex and comparing it with that obtained with the ternary complex (receptor-agonist-G protein) we show that the agonist stabilizes the receptor in a preactivated complex, which is then fully activated upon binding of the G protein. The proposed mechanism contrasts with the generally assumed GPCR activation mechanism, which proceeds through an opening of the intracellular region allosterically elicited by the binding of the agonist. The mechanism found here is consistent with electron cryo-microscopy structural data and might be general for class B GPCRs. It also helps us to understand the mode of action of the numerous allosteric antagonists of this important drug target.
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Affiliation(s)
- Giulio Mattedi
- Department of Chemistry, University College London, London WC1E 6BT, United Kingdom
| | | | - Timothy Clark
- Computer-Chemistry Center, Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen 91052, Germany
| | - Francesco Luigi Gervasio
- Department of Chemistry, University College London, London WC1E 6BT, United Kingdom;
- Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, United Kingdom
- Pharmaceutical Sciences, University of Geneva, Geneva CH-1211, Switzerland
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41
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Galsgaard KD, Jepsen SL, Kjeldsen SAS, Pedersen J, Wewer Albrechtsen NJ, Holst JJ. Alanine, arginine, cysteine, and proline, but not glutamine, are substrates for, and acute mediators of, the liver-α-cell axis in female mice. Am J Physiol Endocrinol Metab 2020; 318:E920-E929. [PMID: 32255678 DOI: 10.1152/ajpendo.00459.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The aim of this study was to identify the amino acids that stimulate glucagon secretion in mice and whose metabolism depends on glucagon receptor signaling. Pancreata of female C57BL/6JRj mice were perfused with 19 individual amino acids and pyruvate (at 10 mM), and secretion of glucagon was assessed using a specific glucagon radioimmunoassay. Separately, a glucagon receptor antagonist (GRA; 25-2648, 100 mg/kg) or vehicle was administered to female C57BL/6JRj mice 3 h before an intraperitoneal injection of four different isomolar amino acid mixtures (in total 7 µmol/g body wt) as follows: mixture 1 contained alanine, arginine, cysteine, and proline; mixture 2 contained aspartate, glutamate, histidine, and lysine; mixture 3 contained citrulline, methionine, serine, and threonine; and mixture 4 contained glutamine, leucine, isoleucine, and valine. Blood glucose, plasma glucagon, amino acid, and insulin concentrations were measured using well-characterized methodologies. Alanine (P = 0.03), arginine (P < 0.0001), cysteine (P = 0.01), glycine (P = 0.02), lysine (P = 0.02), and proline (P = 0.03), but not glutamine (P = 0.9), stimulated glucagon secretion from the perfused mouse pancreas. However, when the four isomolar amino acid mixtures were administered in vivo, the four mixtures elicited similar glucagon responses (P > 0.5). Plasma concentrations of total amino acids in vivo were higher after administration of GRA when mixture 1 (P = 0.004) or mixture 3 (P = 0.04) were injected. Our data suggest that alanine, arginine, cysteine, and proline, but not glutamine, are involved in the acute regulation of the liver-α-cell axis in female mice, as they all increased glucagon secretion and their disappearance rate was altered by GRA.
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Affiliation(s)
- Katrine D Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sara L Jepsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sasha A S Kjeldsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Nephrology and Endocrinology, Nordsjaellands Hospital Hilleroed, University of Copenhagen, Hilleroed, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Osaka N, Kushima H, Mori Y, Saito T, Hiromura M, Terasaki M, Yashima H, Ohara M, Fukui T, Matsui T, Hirano T, Yamagishi SI. Anti-inflammatory and atheroprotective properties of glucagon. Diab Vasc Dis Res 2020; 17:1479164120965183. [PMID: 33076703 PMCID: PMC7919216 DOI: 10.1177/1479164120965183] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Although glucagon has been shown to exert pleiotropic actions in various types of cells and organs through the interaction with its receptor, its pathophysiological role in atherosclerotic cardiovascular disease remains unclear. Here, we examined whether and how glucagon could attenuate the progression of atherosclerotic plaques in apolipoprotein E-deficient mice (ApoE-/-), an animal model of atherosclerosis. Glucagon (138 or 413 nmol/kg/day) or vehicle was infused to mice at 16 weeks of age. After 4-week treatment, vascular samples were collected for histological and RT-PCR analyses. Human monocytic THP-1 cells were pre-incubated with or without a glucagon receptor antagonist L-168049, and then treated with or without glucagon for 7 h. Gene and protein expressions were determined by RT-PCR and western blot analyses, respectively. High-dose glucagon infusion significantly decreased aortic plaque area and volume in ApoE-/- mice, both of which were inversely correlated with plasma glucagon levels. Glucagon infusion also reduced the ratio of pro-inflammatory interleukin-1β to anti-inflammatory interleukin-10 gene expression in aortae. Glucagon receptor was expressed in THP-1 cells, and 1 nM glucagon decreased the ratio of interleukin-1β to interleukin-10 gene expression, which was significantly prevented by L-168049. Our present findings suggest that glucagon could exert atheroprotection partly via its anti-inflammatory property.
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Affiliation(s)
- Naoya Osaka
- Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
| | - Hideki Kushima
- Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
| | - Yusaku Mori
- Anti-glycation Research Section, Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
- Yusaku Mori, Anti-glycation Research Section, Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
| | - Tomomi Saito
- Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
| | - Munenori Hiromura
- Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
| | - Michishige Terasaki
- Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
| | - Hironori Yashima
- Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
| | - Makoto Ohara
- Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
| | - Tomoyasu Fukui
- Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
| | - Takanori Matsui
- Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume, Fukuoka, Japan
| | - Tsutomu Hirano
- Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
- Diabetes Center, Ebina General Hospital, Ebina, Kanagawa, Japan
| | - Sho-ichi Yamagishi
- Division of Diabetes, Metabolism, and Endocrinology, Department of Medicine, Showa University School of Medicine, Shinagawa, Tokyo, Japan
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43
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Huang R, Song T, Su H, Lai Z, Qin W, Tian Y, Dong X, Wang L. High-fat diet enhances starvation-induced hyperactivity via sensitizing hunger-sensing neurons in Drosophila. eLife 2020; 9:e53103. [PMID: 32324135 PMCID: PMC7274782 DOI: 10.7554/elife.53103] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 04/22/2020] [Indexed: 12/14/2022] Open
Abstract
The function of the central nervous system to regulate food intake can be disrupted by sustained metabolic challenges such as high-fat diet (HFD), which may contribute to various metabolic disorders. Previously, we showed that a group of octopaminergic (OA) neurons mediated starvation-induced hyperactivity, an important aspect of food-seeking behavior (Yu et al., 2016). Here we find that HFD specifically enhances this behavior. Mechanistically, HFD increases the excitability of these OA neurons to a hunger hormone named adipokinetic hormone (AKH), via increasing the accumulation of AKH receptor (AKHR) in these neurons. Upon HFD, excess dietary lipids are transported by a lipoprotein LTP to enter these OA+AKHR+ neurons via the cognate receptor LpR1, which in turn suppresses autophagy-dependent degradation of AKHR. Taken together, we uncover a mechanism that links HFD, neuronal autophagy, and starvation-induced hyperactivity, providing insight in the reshaping of neural circuitry under metabolic challenges and the progression of metabolic diseases.
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Affiliation(s)
- Rui Huang
- Center for Neurointelligence, School of Medicine, Chongqing University & Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College, Chongqing UniversityChongqingChina
- Shenzhen Bay LaboratoryShenzhenChina
| | | | - Haifeng Su
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of SciencesShanghaiChina
| | - Zeliang Lai
- Center for Neurointelligence, School of Medicine, Chongqing University & Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College, Chongqing UniversityChongqingChina
- Shenzhen Bay LaboratoryShenzhenChina
| | - Wusa Qin
- Shenzhen Bay LaboratoryShenzhenChina
| | - Yinjun Tian
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang UniversityHangzhouChina
| | - Xuan Dong
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang UniversityHangzhouChina
| | - Liming Wang
- MOE Key Laboratory of Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang UniversityHangzhouChina
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Pei Z, Zhou D, Yan J, Wang S, Yang X, Pei Z. Design and characterization of novel oxyntomodulin derivatives with potent dual GLP-1/glucagon receptor activation and prolonged antidiabetic effects. Life Sci 2020; 253:117651. [PMID: 32304764 DOI: 10.1016/j.lfs.2020.117651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/05/2020] [Accepted: 04/06/2020] [Indexed: 11/18/2022]
Abstract
AIMS To investigate the combination of dimerization and PEGylation to enhance the receptor activation and in vivo stability of Oxyntomodulin (OXM). MAIN METHODS All LDM peptides were produced by using standard method of solid phase synthesis. The in vitro effects of LDM peptides were assessed by glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GcgR) binding test and Proteolytic stability test. Subsequently, saline, Liraglutide and three doses of LDM-3 treated groups were subjected to the evaluation of aute and long-term efficacy. KEY FINDINGS Five long-acting OXM conjugates, termed LDM-1 to LDM-5, were designed using cysteine (Cys)-specific modification reaction including the activated PEG, bisMal-NH2, and OXM-Cys, and all prepared with high purity. LDM-3 exhibited greater GLP-1R and GcgR activation and ameliorative serum stability. In addition, LDM-3 was identified with enhanced insulinotropic and glycemic abilities in the gene knockout mice. The prolonged glucose-lowering effects of the LDM-3 were proved by hypoglycemic duration test and multiple oral glucose tolerance tests (OGTTs) in the diet-induced obesity (DIO) mice. Furthermore, the pharmacokinetic tests in Sprague Dawley (SD) rat and cynomolgus monkey exhibited the lifespans of LDM-3 at 90 nmol·kg-1 were 101.5 h and 119.4 h, respectively. Nevertheless, consecutive 8-week administration of LDM-3 improved the cumulative body weight gain, food intake, % HbA1c, glucose tolerance and the pancreatic of the obese mice. SIGNIFICANCE LDM-3, as a dual GLP-1R and GcgR agonist, holds potential to be developed as a promising therapeutic candidate for both diabetes and obesity.
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Affiliation(s)
- Zengyang Pei
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China; Hangzhou RunChongGuiMei Bio-tech Co., Ltd., Xiao Shan, Hangzhou 310058, PR China.
| | - Degang Zhou
- National Research Center for Veterinary Medicine, Road Cuiwei, High-Tech District, Luoyang 471003, PR China
| | - Jie Yan
- Suzhou Xishan Zhongke Drug R&D Co., Ltd., Wuzhong Avenue, Suzhou 215000, PR China
| | - Shenghao Wang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China
| | - Xu Yang
- Hangzhou RunChongGuiMei Bio-tech Co., Ltd., Xiao Shan, Hangzhou 310058, PR China
| | - Zengju Pei
- Hangzhou RunChongGuiMei Bio-tech Co., Ltd., Xiao Shan, Hangzhou 310058, PR China
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45
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Abstract
Glucagon and its partner insulin are dually linked in both their secretion from islet cells and their action in the liver. Glucagon signaling increases hepatic glucose output, and hyperglucagonemia is partly responsible for the hyperglycemia in diabetes, making glucagon an attractive target for therapeutic intervention. Interrupting glucagon signaling lowers blood glucose but also results in hyperglucagonemia and α-cell hyperplasia. Investigation of the mechanism for α-cell proliferation led to the description of a conserved liver-α-cell axis where glucagon is a critical regulator of amino acid homeostasis. In return, amino acids regulate α-cell function and proliferation. New evidence suggests that dysfunction of the axis in humans may result in the hyperglucagonemia observed in diabetes. This discussion outlines important but often overlooked roles for glucagon that extend beyond glycemia and supports a new role for α-cells as amino acid sensors.
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Affiliation(s)
- E Danielle Dean
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
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46
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Pereira MJ, Thombare K, Sarsenbayeva A, Kamble PG, Almby K, Lundqvist M, Eriksson JW. Direct effects of glucagon on glucose uptake and lipolysis in human adipocytes. Mol Cell Endocrinol 2020; 503:110696. [PMID: 31891768 DOI: 10.1016/j.mce.2019.110696] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 11/25/2019] [Accepted: 12/27/2019] [Indexed: 12/14/2022]
Abstract
We aim to investigate the expression of the glucagon receptor (GCGR) in human adipose tissue, and the impact of glucagon in glucose uptake and lipolysis in human adipocytes. GCGR gene expression in human subcutaneous and visceral adipose tissue was demonstrated, albeit at low levels and with an inter-individual variation. Furthermore, GCGR expression was not significantly different between subjects with T2D and matched controls, and we found no significant association with BMI. Glucagon only at a supra-physiological concentration (10-100 nM) significantly increased basal and insulin-stimulated glucose uptake by up to 1.5-fold. Also, glucagon (0.01 and 1 nM) dose-dependently increased basal and isoproterenol-stimulated lipolysis up to 3.7- and 1.7-fold, respectively, compared to control. In addition, glucagon did not change insulin sensitivity to stimulate glucose uptake or inhibit lipolysis. In conclusion, we show that the GCGR gene is expressed at low levels in human adipose tissue, and glucagon at high concentrations can increase both glucose uptake and lipolysis in human adipocytes. Taken together, our data suggest that glucagon at physiological levels has minor direct effects on the regulation of adipocyte metabolism, but does not antagonize the insulin effect to stimulate glucose uptake and inhibit lipolysis in human adipocytes.
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Affiliation(s)
- Maria J Pereira
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden.
| | - Ketan Thombare
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Assel Sarsenbayeva
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Prasad G Kamble
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Kristina Almby
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Martin Lundqvist
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
| | - Jan W Eriksson
- Department of Medical Sciences, Clinical Diabetes and Metabolism, Uppsala University, Uppsala, Sweden
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Lang S, Yang J, Yang K, Gu L, Cui X, Wei T, Liu J, Le Y, Wang H, Wei R, Hong T. Glucagon receptor antagonist upregulates circulating GLP-1 level by promoting intestinal L-cell proliferation and GLP-1 production in type 2 diabetes. BMJ Open Diabetes Res Care 2020; 8:8/1/e001025. [PMID: 32139602 PMCID: PMC7059498 DOI: 10.1136/bmjdrc-2019-001025] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 01/24/2020] [Accepted: 01/26/2020] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE Glucagon receptor (GCGR) blockage improves glycemic control and increases circulating glucagon-like peptide-1 (GLP-1) level in diabetic animals and humans. The elevated GLP-1 has been reported to be involved in the hypoglycemic effect of GCGR blockage. However, the source of this elevation remains to be clarified. RESEARCH DESIGN AND METHODS REMD 2.59, a human GCGR monoclonal antibody (mAb), was administrated for 12 weeks in db/db mice and high-fat diet+streptozotocin (HFD/STZ)-induced type 2 diabetic (T2D) mice. Blood glucose, glucose tolerance and plasma GLP-1 were evaluated during the treatment. The gut length, epithelial area, and L-cell number and proliferation were detected after the mice were sacrificed. Cell proliferation and GLP-1 production were measured in mouse L-cell line GLUTag cells, and primary mouse and human enterocytes. Moreover, GLP-1 receptor (GLP-1R) antagonist or protein kinase A (PKA) inhibitor was used in GLUTag cells to determine the involved signaling pathways. RESULTS Treatment with the GCGR mAb lowered blood glucose level, improved glucose tolerance and elevated plasma GLP-1 level in both db/db and HFD/STZ-induced T2D mice. Besides, the treatment promoted L-cell proliferation and LK-cell expansion, and increased the gut length, epithelial area and L-cell number in these two T2D mice. Similarly, our in vitro study showed that the GCGR mAb promoted L-cell proliferation and increased GLP-1 production in GLUTag cells, and primary mouse and human enterocytes. Furthermore, either GLP-1R antagonist or PKA inhibitor diminished the effects of GCGR mAb on L-cell proliferation and GLP-1 production. CONCLUSIONS The elevated circulating GLP-1 level by GCGR mAb is mainly due to intestinal L-cell proliferation and GLP-1 production, which may be mediated via GLP-1R/PKA signaling pathways. Therefore, GCGR mAb represents a promising strategy to improve glycemic control and restore the impaired GLP-1 production in T2D.
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Affiliation(s)
- Shan Lang
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| | - Jin Yang
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
| | - Kun Yang
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
| | - Liangbiao Gu
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| | - Xiaona Cui
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| | - Tianjiao Wei
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| | - Junling Liu
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
| | - Yunyi Le
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
| | - Haining Wang
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
| | - Rui Wei
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| | - Tianpei Hong
- Department of Endocrinology and Metabolism, Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
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48
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Mizokami A, Mukai S, Gao J, Kawakubo-Yasukochi T, Otani T, Takeuchi H, Jimi E, Hirata M. GLP-1 signaling is required for improvement of glucose tolerance by osteocalcin. J Endocrinol 2020; 244:285-296. [PMID: 31693486 DOI: 10.1530/joe-19-0288] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 11/05/2019] [Indexed: 11/08/2022]
Abstract
Osteocalcin is a bone-derived hormone that in its uncarboxylated form (GluOC) plays an important role in glucose and energy metabolism by stimulating insulin secretion and pancreatic β-cell proliferation through its putative receptor GPRC6A. We previously showed that the effect of GluOC on insulin secretion is mediated predominantly by glucagon-like peptide-1 (GLP-1) released from intestinal endocrine cells in response to GluOC stimulation. Moreover, oral administration of GluOC was found to reduce the fasting blood glucose level, to improve glucose tolerance, and to increase the fasting serum insulin concentration and β-cell area in the pancreas in wild-type mice. We have now examined the effects of oral GluOC administration for at least 4 weeks in GLP-1 receptor-knockout mice. Such administration of GluOC in the mutant mice triggered glucose intolerance, enhanced gluconeogenesis and promoted both lipid accumulation in the liver as well as adipocyte hypertrophy and inflammation in adipose tissue. Furthermore, inactivation of GLP-1 receptor signaling in association with GluOC administration induced activation of the transcription factor FoxO1 and expression of its transcriptional coactivator PGC1α in the liver, likely accounting for the observed upregulation of gluconeogenic gene expression. Our results thus indicate that the beneficial metabolic effects of GluOC are dependent on GLP-1 receptor signaling.
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Affiliation(s)
- Akiko Mizokami
- OBT Research Center, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Satoru Mukai
- OBT Research Center, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Jing Gao
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Tomoyo Kawakubo-Yasukochi
- Department of Immunological and Molecular Pharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Takahito Otani
- Division of Functional Structure, Department of Morphological Biology, School of Dental Medicine, Fukuoka Dental College, Fukuoka, Japan
| | - Hiroshi Takeuchi
- Division of Applied Pharmacology, Kyushu Dental University, Kitakyushu, Japan
| | - Eijiro Jimi
- OBT Research Center, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Masato Hirata
- Oral Medicine Research Center, School of Dental Medicine, Fukuoka Dental College, Fukuoka, Japan
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49
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Graham GV, McCloskey A, Abdel-Wahab YH, Conlon JM, Flatt PR. A long-acting, dual-agonist analogue of lamprey GLP-1 shows potent insulinotropic, β-cell protective, and anorexic activities and improves glucose homeostasis in high fat-fed mice. Mol Cell Endocrinol 2020; 499:110584. [PMID: 31539596 DOI: 10.1016/j.mce.2019.110584] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/05/2019] [Accepted: 09/16/2019] [Indexed: 12/12/2022]
Abstract
Peptidase-resistant analogues of GLP-1 peptides from sea lamprey and paddlefish ([D-Ala2]palmitoyl-lamprey GLP-1 and [D-Ala2]palmitoyl-paddlefish GLP-1) produced significant (P ≤ 0.05) and concentration-dependent increases in insulin release from BRIN-BD11 clonal β-cells and from isolated mouse islets. Both analogues retained the ability of the native peptides to activate both the GLP-1 receptor (GLP1R) and the glucagon receptor (GCGR). [D-Ala2]palmitoyl-lamprey GLP-1 significantly (P < 0.001) stimulated proliferation of BRIN-BD11 cells and protected against cytokine-induced apoptosis. Administration of the lamprey analogue (25 nmol/kg body weight) to lean mice up to 4 h before a glucose load improved glucose tolerance and increased plasma insulin concentrations. Twice daily administration of the lamprey GLP-1 analogue to high fat-fed mice for 21 days decreased body weight, food intake, and circulating glucose and insulin concentrations. The analogue significantly improved glucose tolerance and insulin sensitivity with beneficial effects on islet β-cell area and insulin secretory responsiveness. Islet gene expression of Glp1r, Gcgr and Gipr significantly increased. The lamprey GLP-1 analogue shows therapeutic promise for treatment of patients with obesity-related Type 2 diabetes.
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Affiliation(s)
- Galyna V Graham
- SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland BT52 1SA, UK
| | - Andrew McCloskey
- SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland BT52 1SA, UK
| | - Yasser H Abdel-Wahab
- SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland BT52 1SA, UK
| | - J Michael Conlon
- SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland BT52 1SA, UK.
| | - Peter R Flatt
- SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland BT52 1SA, UK
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50
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Nason SR, Kim T, Antipenko JP, Finan B, DiMarchi R, Hunter CS, Habegger KM. Glucagon-Receptor Signaling Reverses Hepatic Steatosis Independent of Leptin Receptor Expression. Endocrinology 2020; 161:5610864. [PMID: 31673703 PMCID: PMC7188084 DOI: 10.1210/endocr/bqz013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 10/25/2019] [Indexed: 01/16/2023]
Abstract
Glucagon (GCG) is an essential regulator of glucose and lipid metabolism that also promotes weight loss. We have shown that glucagon-receptor (GCGR) signaling increases fatty acid oxidation (FAOx) in primary hepatocytes and reduces liver triglycerides in diet-induced obese (DIO) mice; however, the mechanisms underlying this aspect of GCG biology remains unclear. Investigation of hepatic GCGR targets elucidated a potent and previously unknown induction of leptin receptor (Lepr) expression. Liver leptin signaling is known to increase FAOx and decrease liver triglycerides, similar to glucagon action. Therefore, we hypothesized that glucagon increases hepatic LEPR, which is necessary for glucagon-mediated reversal of hepatic steatosis. Eight-week-old control and liver-specific LEPR-deficient mice (LeprΔliver) were placed on a high-fat diet for 12 weeks and then treated with a selective GCGR agonist (IUB288) for 14 days. Liver triglycerides and gene expression were assessed in liver tissue homogenates. Administration of IUB288 in both lean and DIO mice increased hepatic Lepr isoforms a-e in acute (4 hours) and chronic (72 hours,16 days) (P < 0.05) settings. LeprΔliver mice displayed increased hepatic triglycerides on a chow diet alone (P < 0.05), which persisted in a DIO state (P < 0.001), with no differences in body weight or composition. Surprisingly, chronic administration of IUB288 in DIO control and LeprΔliver mice reduced liver triglycerides regardless of genotype (P < 0.05). Together, these data suggest that GCGR activation induces hepatic Lepr expression and, although hepatic glucagon and leptin signaling have similar liver lipid targets, these appear to be 2 distinct pathways.
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Affiliation(s)
- Shelly R Nason
- Comprehensive Diabetes Center and Department of Medicine – Division of Endocrinology, Diabetes and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama
| | - Teayoun Kim
- Comprehensive Diabetes Center and Department of Medicine – Division of Endocrinology, Diabetes and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jessica P Antipenko
- Comprehensive Diabetes Center and Department of Medicine – Division of Endocrinology, Diabetes and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama
| | - Brian Finan
- Novo Nordisk Research Center, Indianapolis, IN
| | - Richard DiMarchi
- Novo Nordisk Research Center, Indianapolis, IN
- Department of Chemistry, Indiana University, Bloomington, IN
| | - Chad S Hunter
- Comprehensive Diabetes Center and Department of Medicine – Division of Endocrinology, Diabetes and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kirk M Habegger
- Comprehensive Diabetes Center and Department of Medicine – Division of Endocrinology, Diabetes and Metabolism, University of Alabama at Birmingham, Birmingham, Alabama
- Correspondence and Reprint Requests: Kirk M. Habegger, Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, BDB 783, 1808 7th Avenue South, Birmingham, AL 35294-0012. E-mail:
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