1
|
Mott J, Celly C, Glock R, Gilor C. The glucagon-receptor antagonist MK-3577 reduces glucagon-stimulated plasma glucose and insulin concentrations in metabolically healthy overweight cats. Domest Anim Endocrinol 2024; 89:106874. [PMID: 39018655 DOI: 10.1016/j.domaniend.2024.106874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 07/10/2024] [Accepted: 07/11/2024] [Indexed: 07/19/2024]
Abstract
The role of glucagon disturbances in diabetes mellitus is increasingly recognized and, hence, glucagon antagonism might aid in treatment of hyperglycemia and other metabolic disturbances. The aim of this study was to assess the pharmacokinetics of the glucagon receptor antagonist MK-3577 and its effect on plasma glucose, insulin, and glucagon concentrations in healthy cats. In a cross-over placebo-controlled study, 5 purpose-bred cats were treated with either Placebo, MK-3577 (1 mg/kg), or MK-3577 (3 mg/kg). Glucose, insulin and glucagon concentrations were measured at 0, 15, 225, 240 min post-treatment administration. Glucagon (20 mcg/kg, IM) was administered at 240 min and glucose and insulin were measured at 255, 265, 275, 285 and 300 min. Plasma MK-3577 concentrations peaked at 4.2 and 3.2 hours after 1 and 3 mg/kg dosing with a half-life of 14.8h and 15.5h respectively. Baseline glucose, insulin and glucagon concentrations did not differ significantly between treatment groups. At a dose of 3 mg/kg, MK-3577 blunted the glucagon-stimulated rise of glucose (p=0.0089) and insulin (p=0.02). Similar trends were observed with MK-3577 at the 1 mg/kg dose but the effect was smaller, and not significant. In conclusion, the GRA MK-3577 has a pharmacokinetic profile suitable for diminishing the glucagon-induced rise of glucose and insulin in healthy cats.
Collapse
Affiliation(s)
- J Mott
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, 2015 SW 16th Ave. Gainesville, FL 32608, USA
| | - C Celly
- Merck Animal Health, 126 East Lincoln Avenue, PO Box 2000, Rahway, NJ 07065, USA
| | - R Glock
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon Tharp St., Columbus, OH 43210, USA
| | - C Gilor
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon Tharp St., Columbus, OH 43210, USA; Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, 2015 SW 16th Ave. Gainesville, FL 32608, USA.
| |
Collapse
|
2
|
Perry RJ. Regulation of Hepatic Lipid and Glucose Metabolism by INSP3R1. Diabetes 2022; 71:1834-1841. [PMID: 35657697 PMCID: PMC9450566 DOI: 10.2337/dbi22-0003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 04/13/2022] [Indexed: 11/13/2022]
Abstract
With the rising epidemics of obesity and nonalcoholic fatty liver disease (NAFLD) and its downstream consequences including steatohepatitis, cirrhosis, and type 2 diabetes in the U.S. and worldwide, new therapeutic approaches are urgently needed to treat these devastating conditions. Glucagon, known for a century to be a glucose-raising hormone and clearly demonstrated to contribute to fasting and postprandial hyperglycemia in both type 1 and type 2 diabetes, represents an unlikely target to improve health in those with metabolic syndrome. However, recent work from our group and others' identifies an unexpected role for glucagon as a potential means of treating NAFLD, improving insulin sensitivity, and improving the lipid profile. We propose a unifying, calcium-dependent mechanism for glucagon's effects both to stimulate hepatic gluconeogenesis and to enhance hepatic mitochondrial oxidation: signaling through the inositol 1,4,5-trisphosphate receptor type 1 (INSP3R1), glucagon activates phospholipase C (PKC)/protein kinase A (PKA) signaling to enhance adipose triglyceride lipase (ATGL)-dependent intrahepatic lipolysis and, in turn, increase cytosolic gluconeogenesis by allosteric activation of pyruvate carboxylase. Simultaneously in the mitochondria, calcium transferred through mitochondria-associated membranes activates several dehydrogenases in the tricarboxylic acid cycle, correlated with an increase in mitochondrial energy expenditure and reduction in ectopic lipid. This model suggests that short-term, cyclic treatment with glucagon or other INSP3R1 antagonists could hold promise as a means to reset lipid homeostasis in patients with NAFLD.
Collapse
Affiliation(s)
- Rachel J. Perry
- Section of Endocrinology & Metabolism, Department of Internal Medicine, and Department of Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT
| |
Collapse
|
3
|
Yang B, Gelfanov VM, Perez-Tilve D, DuBois B, Rohlfs R, Levy J, Douros JD, Finan B, Mayer JP, DiMarchi RD. Optimization of Truncated Glucagon Peptides to Achieve Selective, High Potency, Full Antagonists. J Med Chem 2021; 64:4697-4708. [PMID: 33821647 DOI: 10.1021/acs.jmedchem.0c02069] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Antagonism of glucagon's biological action is a proven strategy for decreasing glucose in diabetic animals and patients. To achieve full, potent, and selective suppression, we chemically optimized N-terminally truncated glucagon fragments for the identification and establishment of the minimum sequence peptide, [Glu9]glucagon(6-29) amide (11) as a full antagonist in cellular signaling and receptor binding (IC50 = 36 nM). Substitution of Phe6 with l-3-phenyllactic acid (Pla) produced [Pla6, Glu9]glucagon(6-29) amide (21), resulting in a 3-fold improvement in receptor binding (IC50 = 12 nM) and enhanced antagonist potency. Further substitution of Glu9 and Asn28 with aspartic acid yielded [Pla6, Asp28]glucagon amide (26), which demonstrated a further increase in inhibitory potency (IC50 = 9 nM), and improved aqueous solubility. Peptide 26 and a palmitoylated analogue, [Pla6, Lys10(γGluγGlu-C16), Asp28]glucagon(6-29) amide (31), displayed sustained duration in vivo action that successfully reversed glucagon-induced glucose elevation in mice.
Collapse
Affiliation(s)
- Bin Yang
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States.,Novo Nordisk Research Center Indianapolis, Indianapolis, Indiana 46241, United States
| | - Vasily M Gelfanov
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States.,Novo Nordisk Research Center Indianapolis, Indianapolis, Indiana 46241, United States
| | - Diego Perez-Tilve
- Department of Medicine, University of Cincinnati, Cincinnati, Ohio 45267, United States
| | - Barent DuBois
- Novo Nordisk Research Center Indianapolis, Indianapolis, Indiana 46241, United States
| | - Rebecca Rohlfs
- Novo Nordisk Research Center Indianapolis, Indianapolis, Indiana 46241, United States
| | - Jay Levy
- Novo Nordisk Research Center Indianapolis, Indianapolis, Indiana 46241, United States
| | - Jonathan D Douros
- Novo Nordisk Research Center Indianapolis, Indianapolis, Indiana 46241, United States
| | - Brian Finan
- Novo Nordisk Research Center Indianapolis, Indianapolis, Indiana 46241, United States
| | - John P Mayer
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Richard D DiMarchi
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| |
Collapse
|
4
|
Pettus JH, D'Alessio D, Frias JP, Vajda EG, Pipkin JD, Rosenstock J, Williamson G, Zangmeister MA, Zhi L, Marschke KB. Efficacy and Safety of the Glucagon Receptor Antagonist RVT-1502 in Type 2 Diabetes Uncontrolled on Metformin Monotherapy: A 12-Week Dose-Ranging Study. Diabetes Care 2020; 43:161-168. [PMID: 31694861 DOI: 10.2337/dc19-1328] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 10/15/2019] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Evaluate the safety and efficacy of RVT-1502, a novel oral glucagon receptor antagonist, in subjects with type 2 diabetes inadequately controlled on metformin. RESEARCH DESIGN AND METHODS In a phase 2, double-blind, randomized, placebo-controlled study, subjects with type 2 diabetes (n = 166) on a stable dose of metformin were randomized (1:1:1:1) to placebo or RVT-1502 5, 10, or 15 mg once daily for 12 weeks. The primary end point was change from baseline in HbA1c for each dose of RVT-1502 compared with placebo. Secondary end points included change from baseline in fasting plasma glucose (FPG) and safety assessments. RESULTS Over 12 weeks, RVT-1502 significantly reduced HbA1c relative to placebo by 0.74%, 0.76%, and 1.05% in the 5-, 10-, and 15-mg groups (P < 0.001), respectively, and FPG decreased by 2.1, 2.2, and 2.6 mmol/L (P < 0.001). The proportions of subjects achieving an HbA1c <7.0% were 19.5%, 39.5%, 39.5%, and 45.0% with placebo and RVT-1502 5, 10, and 15 mg (P ≤ 0.02 vs. placebo). The frequency of hypoglycemia was low, and no episodes were severe. Mild increases in mean aminotransferase levels remaining below the upper limit of normal were observed with RVT-1502 but were reversible and did not appear to be dose related, with no other liver parameter changes. Weight and lipid changes were similar between RVT-1502 and placebo. RVT-1502-associated mild increases in blood pressure were not dose related or consistent across time. CONCLUSIONS Glucagon receptor antagonism with RVT-1502 significantly lowers HbA1c and FPG, with a safety profile that supports further clinical development with longer-duration studies (NCT02851849).
Collapse
Affiliation(s)
| | | | | | - Eric G Vajda
- Ligand Pharmaceuticals Incorporated, San Diego, CA
| | | | | | | | | | - Lin Zhi
- Ligand Pharmaceuticals Incorporated, San Diego, CA
| | | |
Collapse
|
5
|
Xu G, Gaul MD, Song F, Du F, Liang Y, DesJarlais RL, DiLoreto K, Shook B, Rentzeperis D, Santulli R, Eckardt A, Demarest K. Discovery of potent and orally bioavailable indazole-based glucagon receptor antagonists for the treatment of type 2 diabetes. Bioorg Med Chem Lett 2019; 29:126668. [DOI: 10.1016/j.bmcl.2019.126668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 08/30/2019] [Accepted: 09/03/2019] [Indexed: 12/27/2022]
|
6
|
Lee M, Kim M, Park JS, Lee S, You J, Ahn CW, Kim KR, Kang S. Higher glucagon-to-insulin ratio is associated with elevated glycated hemoglobin levels in type 2 diabetes patients. Korean J Intern Med 2019; 34:1068-1077. [PMID: 28882024 PMCID: PMC6718759 DOI: 10.3904/kjim.2016.233] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 06/26/2017] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND/AIMS The importance of α-cell dysfunction in the pathogenesis of type 2 diabetes has re-emerged recently. However, data on whether relative glucagon excess is present in clinical settings are scarce. We aimed to investigate associations between glucagon-to-insulin ratio and various metabolic parameters. METHODS A total of 451 patients with type 2 diabetes naïve to insulin treatment were recruited. Using glucagon-to-insulin ratio, we divided subjects into quartiles according to both fasting and postprandial glucagon-to-insulin ratios. RESULTS The mean age of the subjects was 58 years, with a mean body mass index of 25 kg/m2 . The patients in the highest quartile of glucagon-to-insulin ratio had higher glycated hemoglobin (HbA1c) levels. HbA1c levels were positively correlated with both fasting and postprandial glucagon-to-insulin ratios. Subjects in the highest quartile of postprandial glucagon-to-insulin ratio were more likely to exhibit uncontrolled hyperglycemia, even after adjusting for confounding factors (odds ratio, 2.730; 95% confidence interval, 1.236 to 6.028; p for trend < 0.01). CONCLUSION Hyperglucagonemia relative to insulin could contribute to uncontrolled hyperglycemia in type 2 diabetes patients.
Collapse
Affiliation(s)
- Minyoung Lee
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Minkyung Kim
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jong Suk Park
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
- Severance Institute for Vascular and Metabolic Research, Yonsei University College of Medicine, Seoul, Korea
| | - Sangbae Lee
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jihong You
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Chul Woo Ahn
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
- Severance Institute for Vascular and Metabolic Research, Yonsei University College of Medicine, Seoul, Korea
| | - Kyung Rae Kim
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Shinae Kang
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
- Severance Institute for Vascular and Metabolic Research, Yonsei University College of Medicine, Seoul, Korea
- Correspondence to Shinae Kang, M.D. Division of Endocrinology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, 211 Eonju-ro, Gangnam-gu, Seoul 06273, Korea Tel: +82-2-2019-3335 Fax: +82-2-3463-3882 E-mail:
| |
Collapse
|
7
|
Müller TD, Clemmensen C, Finan B, DiMarchi RD, Tschöp MH. Anti-Obesity Therapy: from Rainbow Pills to Polyagonists. Pharmacol Rev 2019; 70:712-746. [PMID: 30087160 DOI: 10.1124/pr.117.014803] [Citation(s) in RCA: 117] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
With their ever-growing prevalence, obesity and diabetes represent major health threats of our society. Based on estimations by the World Health Organization, approximately 300 million people will be obese in 2035. In 2015 alone there were more than 1.6 million fatalities attributable to hyperglycemia and diabetes. In addition, treatment of these diseases places an enormous burden on our health care system. As a result, the development of pharmacotherapies to tackle this life-threatening pandemic is of utmost importance. Since the beginning of the 19th century, a variety of drugs have been evaluated for their ability to decrease body weight and/or to improve deranged glycemic control. The list of evaluated drugs includes, among many others, sheep-derived thyroid extracts, mitochondrial uncouplers, amphetamines, serotonergics, lipase inhibitors, and a variety of hormones produced and secreted by the gastrointestinal tract or adipose tissue. Unfortunately, when used as a single hormone therapy, most of these drugs are underwhelming in their efficacy or safety, and placebo-subtracted weight loss attributed to such therapy is typically not more than 10%. In 2009, the generation of a single molecule with agonism at the receptors for glucagon and the glucagon-like peptide 1 broke new ground in obesity pharmacology. This molecule combined the beneficial anorectic and glycemic effects of glucagon-like peptide 1 with the thermogenic effect of glucagon into a single molecule with enhanced potency and sustained action. Several other unimolecular dual agonists have subsequently been developed, and, based on their preclinical success, these molecules illuminate the path to a new and more fruitful era in obesity pharmacology. In this review, we focus on the historical pharmacological approaches to treat obesity and glucose intolerance and describe how the knowledge obtained by these studies led to the discovery of unimolecular polypharmacology.
Collapse
Affiliation(s)
- T D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany (T.D.M., C.C., M.H.T.); German Center for Diabetes Research, Neuherberg, Germany (T.D.M., C.C., M.H.T.); Department of Chemistry, Indiana University, Bloomington, Indiana (B.F., R.D.D.); and Division of Metabolic Diseases, Technische Universität München, Munich, Germany (M.H.T.)
| | - C Clemmensen
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany (T.D.M., C.C., M.H.T.); German Center for Diabetes Research, Neuherberg, Germany (T.D.M., C.C., M.H.T.); Department of Chemistry, Indiana University, Bloomington, Indiana (B.F., R.D.D.); and Division of Metabolic Diseases, Technische Universität München, Munich, Germany (M.H.T.)
| | - B Finan
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany (T.D.M., C.C., M.H.T.); German Center for Diabetes Research, Neuherberg, Germany (T.D.M., C.C., M.H.T.); Department of Chemistry, Indiana University, Bloomington, Indiana (B.F., R.D.D.); and Division of Metabolic Diseases, Technische Universität München, Munich, Germany (M.H.T.)
| | - R D DiMarchi
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany (T.D.M., C.C., M.H.T.); German Center for Diabetes Research, Neuherberg, Germany (T.D.M., C.C., M.H.T.); Department of Chemistry, Indiana University, Bloomington, Indiana (B.F., R.D.D.); and Division of Metabolic Diseases, Technische Universität München, Munich, Germany (M.H.T.)
| | - M H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany (T.D.M., C.C., M.H.T.); German Center for Diabetes Research, Neuherberg, Germany (T.D.M., C.C., M.H.T.); Department of Chemistry, Indiana University, Bloomington, Indiana (B.F., R.D.D.); and Division of Metabolic Diseases, Technische Universität München, Munich, Germany (M.H.T.)
| |
Collapse
|
8
|
Brandt SJ, Müller TD, DiMarchi RD, Tschöp MH, Stemmer K. Peptide-based multi-agonists: a new paradigm in metabolic pharmacology. J Intern Med 2018; 284:581-602. [PMID: 30230640 DOI: 10.1111/joim.12837] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Obesity and its comorbidities, such as type 2 diabetes, are pressing worldwide health concerns. Available anti-obesity treatments include weight loss pharmacotherapies and bariatric surgery. Whilst surgical interventions typically result in significant and sustained weight loss, available pharmacotherapies are far less effective, typically decreasing body weight by no more than 5-10%. An emerging class of multi-agonist drugs may eventually bridge this gap. This new class of specially tailored drugs hybridizes the amino acid sequences of key metabolic hormones into one single entity with enhanced potency and sustained action. Successful examples of this strategy include multi-agonist drugs targeting the receptors for glucagon-like peptide-1 (GLP-1), glucagon and the glucose-dependent insulinotropic polypeptide (GIP). Due to the simultaneous activity at several metabolically relevant receptors, these multi-agonists offer improved body weight loss and glucose tolerance relative to their constituent monotherapies. Further advancing this concept, chimeras were generated that covalently link nuclear acting hormones such as oestrogen, thyroid hormone (T3 ) or dexamethasone to peptide hormones such as GLP-1 or glucagon. The benefit of this strategy is to restrict the nuclear hormone action exclusively to cells expressing the peptide hormone receptor, thereby maximizing combinatorial metabolic efficacy of both drug constituents in the target cells whilst preventing the nuclear hormone cargo from entering and acting on cells devoid of the peptide hormone receptor, in which the nuclear hormone might have unwanted effects. Many of these multi-agonists are in preclinical and clinical development and may represent new and effective tools in the fight against obesity and its comorbidities.
Collapse
Affiliation(s)
- S J Brandt
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - T D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - R D DiMarchi
- Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - M H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany.,Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - K Stemmer
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| |
Collapse
|
9
|
Zhou TT, Ma F, Shi XF, Xu X, Du T, Guo XD, Wang GH, Yu L, Rukachaisirikul V, Hu LH, Chen J, Shen X. DMT efficiently inhibits hepatic gluconeogenesis by regulating the Gαq signaling pathway. J Mol Endocrinol 2017. [PMID: 28637808 DOI: 10.1530/jme-17-0121] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with complicated pathogenesis and targeting gluconeogenesis inhibition is a promising strategy for anti-diabetic drug discovery. G protein-coupled receptors (GPCRs) are classified as distinct families by heterotrimeric G proteins, primarily including Gαs, Gαi and Gαq. Gαs-coupled GPCRs function potently in the regulation of hepatic gluconeogenesis by activating cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway and Gαi-coupled GPCRs exhibit inhibitory effect on adenylyl cyclase and reduce intracellular cAMP level. However, little is known about the regulation of Gαq-coupled GPCRs in hepatic gluconeogenesis. Here, small-molecule 2-(2,4-dimethoxy-3-methylphenyl)-7-(thiophen-2-yl)-9-(trifluoromethyl)-2,3-dihydropyrido[3',2':4,5]thieno[3,2-d]pyrimidin-4(1H)-one (DMT) was determined to suppress hepatic glucose production and reduce mRNA levels of gluconeogenic genes. Treatment of DMT in db/db mice decreased fasting blood glucose and hemoglobin A1C (HbA1c) levels, while improved glucose tolerance and pyruvate tolerance. Mechanism study demonstrated that DMT-inhibited gluconeogenesis by regulating the Gαq/phospholipase C (PLC)/inositol-1,4,5-triphosphate receptor (IP3R)-mediated calcium (Ca2+)/calmodulin (CaM)/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT)/forkhead box protein O1 (FOXO1) signaling pathway. To our knowledge, DMT might be the first reported small molecule able to suppress hepatic gluconeogenesis by regulating Gαq signaling, and our current work has also highlighted the potential of DMT in the treatment of T2DM.
Collapse
Affiliation(s)
- Ting-Ting Zhou
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of SciencesBeijing, China
| | - Fei Ma
- School of PharmacyEast China University of Science and Technology, Shanghai, China
| | - Xiao-Fan Shi
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of SciencesBeijing, China
| | - Xin Xu
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of SciencesBeijing, China
| | - Te Du
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of SciencesBeijing, China
| | - Xiao-Dan Guo
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of SciencesBeijing, China
| | - Gai-Hong Wang
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Liang Yu
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of SciencesBeijing, China
| | | | - Li-Hong Hu
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of SciencesBeijing, China
| | - Jing Chen
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of SciencesBeijing, China
| | - Xu Shen
- Key Laboratory of Receptor ResearchShanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of SciencesBeijing, China
- Key Laboratory of Drug Target and Drug for Degenerative DiseaseSchool of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, China
| |
Collapse
|
10
|
Müller TD, Finan B, Clemmensen C, DiMarchi RD, Tschöp MH. The New Biology and Pharmacology of Glucagon. Physiol Rev 2017; 97:721-766. [PMID: 28275047 DOI: 10.1152/physrev.00025.2016] [Citation(s) in RCA: 206] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In the last two decades we have witnessed sizable progress in defining the role of gastrointestinal signals in the control of glucose and energy homeostasis. Specifically, the molecular basis of the huge metabolic benefits in bariatric surgery is emerging while novel incretin-based medicines based on endogenous hormones such as glucagon-like peptide 1 and pancreas-derived amylin are improving diabetes management. These and related developments have fostered the discovery of novel insights into endocrine control of systemic metabolism, and in particular a deeper understanding of the importance of communication across vital organs, and specifically the gut-brain-pancreas-liver network. Paradoxically, the pancreatic peptide glucagon has reemerged in this period among a plethora of newly identified metabolic macromolecules, and new data complement and challenge its historical position as a gut hormone involved in metabolic control. The synthesis of glucagon analogs that are biophysically stable and soluble in aqueous solutions has promoted biological study that has enriched our understanding of glucagon biology and ironically recruited glucagon agonism as a central element to lower body weight in the treatment of metabolic disease. This review summarizes the extensive historical record and the more recent provocative direction that integrates the prominent role of glucagon in glucose elevation with its under-acknowledged effects on lipids, body weight, and vascular health that have implications for the pathophysiology of metabolic diseases, and the emergence of precision medicines to treat metabolic diseases.
Collapse
Affiliation(s)
- T D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research, Neuherberg, Germany; Department of Chemistry, Indiana University, Bloomington, Indiana; Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - B Finan
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research, Neuherberg, Germany; Department of Chemistry, Indiana University, Bloomington, Indiana; Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - C Clemmensen
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research, Neuherberg, Germany; Department of Chemistry, Indiana University, Bloomington, Indiana; Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - R D DiMarchi
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research, Neuherberg, Germany; Department of Chemistry, Indiana University, Bloomington, Indiana; Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| | - M H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; German Center for Diabetes Research, Neuherberg, Germany; Department of Chemistry, Indiana University, Bloomington, Indiana; Division of Metabolic Diseases, Technische Universität München, Munich, Germany
| |
Collapse
|
11
|
Vajda EG, Logan D, Lasseter K, Armas D, Plotkin DJ, Pipkin JD, Li YX, Zhou R, Klein D, Wei X, Dilzer S, Zhi L, Marschke KB. Pharmacokinetics and pharmacodynamics of single and multiple doses of the glucagon receptor antagonist LGD-6972 in healthy subjects and subjects with type 2 diabetes mellitus. Diabetes Obes Metab 2017; 19:24-32. [PMID: 27501510 PMCID: PMC5215471 DOI: 10.1111/dom.12752] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/26/2016] [Accepted: 07/27/2016] [Indexed: 01/21/2023]
Abstract
AIM To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of single and multiple doses of a novel, oral glucagon receptor antagonist, LGD-6972, in healthy subjects and subjects with type 2 diabetes (T2DM). METHODS In the single ascending dose study, LGD-6972 (2-480 mg) was administered to healthy subjects (n = 48) and T2DM subjects (n = 8). In the multiple ascending dose study, healthy subjects (n = 12) received a dose of 15 mg LGD-6972 and T2DM subjects (n = 36) received doses of 5, 10 or 15 mg of LGD-6972 daily for 14 days. RESULTS LGD-6972 had linear plasma pharmacokinetics consistent with once-daily dosing that was comparable in healthy and T2DM subjects. Dose-dependent decreases in fasting plasma glucose were observed in all groups with a maximum of 3.15 mmol/L (56.8 mg/dL) on day 14 in T2DM subjects. LGD-6972 also reduced plasma glucose in the postprandial state. Dose-dependent increases in fasting plasma glucagon were observed, but glucagon levels decreased and insulin levels increased after an oral glucose load in T2DM subjects. LGD-6972 was well tolerated at the doses tested without dose-related or clinically meaningful changes in clinical laboratory parameters. No subject experienced hypoglycaemia. CONCLUSION Inhibition of glucagon action by LGD-6972 was associated with decreases in glucose in both healthy and T2DM subjects, the magnitude of which was sufficient to predict improvement in glycaemic control with longer treatment duration in T2DM patients. The safety and pharmacological profile of LGD-6972 after 14 days of dosing supports continued clinical development.
Collapse
Affiliation(s)
- Eric G. Vajda
- Ligand Pharmaceuticals IncorporatedSan DiegoCaliforniaUSA
| | - Douglas Logan
- Cincinnati VA Medical Center Ringgold Standard InstitutionCincinnatiOhioUSA
| | | | | | | | - JD Pipkin
- Ligand Pharmaceuticals IncorporatedSan DiegoCaliforniaUSA
| | | | | | | | | | - Stacy Dilzer
- Clinical Pharmacology of Miami, Inc.MiamiFloridaUSA
| | - Lin Zhi
- Ligand Pharmaceuticals IncorporatedSan DiegoCaliforniaUSA
| | | |
Collapse
|
12
|
Rines AK, Sharabi K, Tavares CDJ, Puigserver P. Targeting hepatic glucose metabolism in the treatment of type 2 diabetes. Nat Rev Drug Discov 2016; 15:786-804. [PMID: 27516169 DOI: 10.1038/nrd.2016.151] [Citation(s) in RCA: 232] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Type 2 diabetes mellitus is characterized by the dysregulation of glucose homeostasis, resulting in hyperglycaemia. Although current diabetes treatments have exhibited some success in lowering blood glucose levels, their effect is not always sustained and their use may be associated with undesirable side effects, such as hypoglycaemia. Novel antidiabetic drugs, which may be used in combination with existing therapies, are therefore needed. The potential of specifically targeting the liver to normalize blood glucose levels has not been fully exploited. Here, we review the molecular mechanisms controlling hepatic gluconeogenesis and glycogen storage, and assess the prospect of therapeutically targeting associated pathways to treat type 2 diabetes.
Collapse
Affiliation(s)
- Amy K Rines
- Department of Cancer Biology, Dana-Farber Cancer Institute, and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Kfir Sharabi
- Department of Cancer Biology, Dana-Farber Cancer Institute, and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Clint D J Tavares
- Department of Cancer Biology, Dana-Farber Cancer Institute, and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Pere Puigserver
- Department of Cancer Biology, Dana-Farber Cancer Institute, and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| |
Collapse
|
13
|
Bankir L, Bouby N, Blondeau B, Crambert G. Glucagon actions on the kidney revisited: possible role in potassium homeostasis. Am J Physiol Renal Physiol 2016; 311:F469-86. [DOI: 10.1152/ajprenal.00560.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/31/2016] [Indexed: 12/25/2022] Open
Abstract
It is now recognized that the metabolic disorders observed in diabetes are not, or not only due to the lack of insulin or insulin resistance, but also to elevated glucagon secretion. Accordingly, selective glucagon receptor antagonists are now proposed as a novel strategy for the treatment of diabetes. However, besides its metabolic actions, glucagon also influences kidney function. The glucagon receptor is expressed in the thick ascending limb, distal tubule, and collecting duct, and glucagon regulates the transepithelial transport of several solutes in these nephron segments. Moreover, it also influences solute transport in the proximal tubule, possibly by an indirect mechanism. This review summarizes the knowledge accumulated over the last 30 years about the influence of glucagon on the renal handling of electrolytes and urea. It also describes a possible novel role of glucagon in the short-term regulation of potassium homeostasis. Several original findings suggest that pancreatic α-cells may express a “potassium sensor” sensitive to changes in plasma K concentration and could respond by adapting glucagon secretion that, in turn, would regulate urinary K excretion. By their combined actions, glucagon and insulin, working in a combinatory mode, could ensure an independent regulation of both plasma glucose and plasma K concentrations. The results and hypotheses reviewed here suggest that the use of glucagon receptor antagonists for the treatment of diabetes should take into account their potential consequences on electrolyte handling by the kidney.
Collapse
Affiliation(s)
- Lise Bankir
- INSERM UMRS 1138, Centre de Recherche des Cordeliers, Paris, France
- Université Pierre et Marie Curie, Paris, France; and
| | - Nadine Bouby
- INSERM UMRS 1138, Centre de Recherche des Cordeliers, Paris, France
- Université Pierre et Marie Curie, Paris, France; and
- Université Paris-Descartes, Paris, France
| | - Bertrand Blondeau
- INSERM UMRS 1138, Centre de Recherche des Cordeliers, Paris, France
- Université Pierre et Marie Curie, Paris, France; and
| | - Gilles Crambert
- INSERM UMRS 1138, Centre de Recherche des Cordeliers, Paris, France
- Université Pierre et Marie Curie, Paris, France; and
| |
Collapse
|
14
|
Lin S, Zhang F, Jiang G, Qureshi SA, Yang X, Chicchi GG, Tota L, Bansal A, Brady E, Trujillo M, Salituro G, Miller C, Tata JR, Zhang BB, Parmee ER. A novel series of indazole-/indole-based glucagon receptor antagonists. Bioorg Med Chem Lett 2015; 25:4143-7. [PMID: 26303893 DOI: 10.1016/j.bmcl.2015.08.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/29/2015] [Accepted: 08/06/2015] [Indexed: 02/02/2023]
Abstract
A novel, potent series of glucagon receptor antagonists (GRAs) was discovered. These indazole- and indole-based compounds were designed on an earlier pyrazole-based GRA lead MK-0893. Structure-activity relationship (SAR) studies were focused on the C3 and C6 positions of the indazole core, as well as the benzylic position on the N-1 of indazole. Multiple potent GRAs were identified with excellent in vitro profiles and good pharmacokinetics in rat. Among them, GRA 16d was found to be orally active in blunting glucagon induced glucose excursion in an acute glucagon challenge model in glucagon receptor humanized (hGCGR) mice at 1, 3 and 10mg/kg (mpk), and significantly lowered acute glucose levels in hGCGR ob/ob mice at 3 mpk dose.
Collapse
Affiliation(s)
- Songnian Lin
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States.
| | - Fengqi Zhang
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Guoqiang Jiang
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Sajjad A Qureshi
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Xiaodong Yang
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Gary G Chicchi
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Laurie Tota
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Alka Bansal
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Edward Brady
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Maria Trujillo
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Gino Salituro
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Corey Miller
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - James R Tata
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Bei B Zhang
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| | - Emma R Parmee
- Early Development and Discovery Science, and Preclinical Development, Merck Research Laboratories, 2015 Galloping Hill Rd, Kenilworth, NJ 07033, United States
| |
Collapse
|
15
|
Lotfy M, Kalasz H, Szalai G, Singh J, Adeghate E. Recent Progress in the Use of Glucagon and Glucagon Receptor Antago-nists in the Treatment of Diabetes Mellitus. THE OPEN MEDICINAL CHEMISTRY JOURNAL 2014; 8:28-35. [PMID: 25674162 PMCID: PMC4321206 DOI: 10.2174/1874104501408010028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 10/08/2014] [Accepted: 10/12/2014] [Indexed: 12/25/2022]
Abstract
Glucagon is an important pancreatic hormone, released into blood circulation by alpha cells of the islet of
Langerhans. Glucagon induces gluconeogenesis and glycogenolysis in hepatocytes, leading to an increase in hepatic glucose
production and subsequently hyperglycemia in susceptible individuals. Hyperglucagonemia is a constant feature in
patients with T2DM. A number of bioactive agents that can block glucagon receptor have been identified. These glucagon
receptor antagonists can reduce the hyperglycemia associated with exogenous glucagon administration in normal as well
as diabetic subjects. Glucagon receptor antagonists include isoserine and beta-alanine derivatives, bicyclic 19-residue peptide
BI-32169, Des-His1-[Glu9] glucagon amide and related compounds, 5-hydroxyalkyl-4-phenylpyridines, N-[3-cano-6-
(1,1 dimethylpropyl)-4,5,6,7-tetrahydro-1-benzothien-2-yl]-2-ethylbutamide, Skyrin and NNC 250926. The absorption,
dosage, catabolism, excretion and medicinal chemistry of these agents are the subject of this review. It emphasizes the
role of glucagon in glucose homeostasis and how it could be applied as a novel tool for the management of diabetes mellitus
by blocking its receptors with either monoclonal antibodies, peptide and non-peptide antagonists or gene knockout
techniques.
Collapse
Affiliation(s)
- Mohamed Lotfy
- Department of Biology, College of Science, United Arab Emirates University; School of Forensic and Investigative Sciences, University of Central Lancashire, Preston PR1 2HE, England, UK; National Research Centre, Hormones Department, Cairo, Egypt
| | - Huba Kalasz
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Gyorgy Szalai
- ENT Department, St. Janos Hospital, Budapest, Hungary
| | - Jaipaul Singh
- School of Forensic and Investigative Sciences and School of Pharmacy and Biomedical Science, University of Central Lancashire, Preston PR1 2HE, England, UK
| | - Ernest Adeghate
- Department of Anatomy, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Ar-ab Emirates
| |
Collapse
|
16
|
Ahrén B, Gautier JF, Berria R, Stager W, Aronson R, Bailey CJ. Pronounced reduction of postprandial glucagon by lixisenatide: a meta-analysis of randomized clinical trials. Diabetes Obes Metab 2014; 16:861-8. [PMID: 24641271 DOI: 10.1111/dom.12290] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 12/19/2013] [Accepted: 03/11/2014] [Indexed: 01/03/2023]
Abstract
AIM Glucagon-like peptide-1 (GLP-1) receptor agonists improve islet function and delay gastric emptying in patients with type 2 diabetes mellitus (T2DM). This meta-analysis aimed to investigate the effects of the once-daily prandial GLP-1 receptor agonist lixisenatide on postprandial plasma glucose (PPG), glucagon and insulin levels. METHODS Six randomized, placebo-controlled studies of lixisenatide 20 µg once daily were included in this analysis: lixisenatide as monotherapy (GetGoal-Mono), as add-on to oral antidiabetic drugs (OADs; GetGoal-M, GetGoal-S) or in combination with basal insulin (GetGoal-L, GetGoal-Duo-1 and GetGoal-L-Asia). Change in 2-h PPG and glucose excursion were evaluated across six studies. Change in 2-h glucagon and postprandial insulin were evaluated across two studies. A meta-analysis was performed on least square (LS) mean estimates obtained from analysis of covariance (ANCOVA)-based linear regression. RESULTS Lixisenatide significantly reduced 2-h PPG from baseline (LS mean difference vs. placebo: -4.9 mmol/l, p < 0.001) and glucose excursion (LS mean difference vs. placebo: -4.5 mmol/l, p < 0.001). As measured in two studies, lixisenatide also reduced postprandial glucagon (LS mean difference vs. placebo: -19.0 ng/l, p < 0.001) and insulin (LS mean difference vs. placebo: -64.8 pmol/l, p < 0.001). There was a stronger correlation between 2-h postprandial glucagon and 2-h PPG with lixisenatide than with placebo. CONCLUSIONS Lixisenatide significantly reduced 2-h PPG and glucose excursion together with a marked reduction in postprandial glucagon and insulin; thus, lixisenatide appears to have biological effects on blood glucose that are independent of increased insulin secretion. These effects may be, in part, attributed to reduced glucagon secretion.
Collapse
Affiliation(s)
- B Ahrén
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | | | | | | | | | | |
Collapse
|
17
|
Jones HB, Reens J, Brocklehurst SR, Betts CJ, Bickerton S, Bigley AL, Jenkins RP, Whalley NM, Morgan D, Smith DM. Islets of Langerhans from prohormone convertase-2 knockout mice show α-cell hyperplasia and tumorigenesis with elevated α-cell neogenesis. Int J Exp Pathol 2014; 95:29-48. [PMID: 24456331 DOI: 10.1111/iep.12066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 11/14/2013] [Indexed: 01/24/2023] Open
Abstract
Antagonism of the effects of glucagon as an adjunct therapy with other glucose-lowering drugs in the chronic treatment of diabetes has been suggested to aggressively control blood glucose levels. Antagonism of glucagon effects, by targeting glucagon secretion or disabling the glucagon receptor, is associated with α-cell hyperplasia. We evaluated the influence of total glucagon withdrawal on islets of Langerhans using prohormone convertase-2 knockout mice (PC2-ko), in which α-cell hyperplasia is present from a young age and persists throughout life, in order to understand whether or not sustained glucagon deficit would lead to islet tumorigenesis. PC2-ko and wild-type (WT) mice were maintained drug-free, and cohorts of these groups sampled at 3, 12 and 18 months for plasma biochemical and morphological (histological, immunohistochemical, electron microscopical and image analytical) assessments. WT mice showed no islet tumours up to termination of the study, but PC2-ko animals displayed marked changes in islet morphology from α-cell hypertrophy/hyperplasia/atypical hyperplasia, to adenomas and carcinomas, these latter being first encountered at 6-8 months. Islet hyperplasias and tumours primarily consisted of α-cells associated to varying degrees with other islet endocrine cell types. In addition to substantial increases in islet neoplasia, increased α-cell neogenesis associated primarily with pancreatic duct(ule)s was present. We conclude that absolute blockade of the glucagon signal results in tumorigenesis and that the PC2-ko mouse represents a valuable model for investigation of islet tumours and pancreatic ductal neogenesis.
Collapse
Affiliation(s)
- Huw B Jones
- Department of Pathological Sciences, AstraZeneca Pharmaceuticals, Macclesfield, Cheshire, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Identification of a novel conformationally constrained glucagon receptor antagonist. Bioorg Med Chem Lett 2014; 24:839-44. [DOI: 10.1016/j.bmcl.2013.12.090] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 11/22/2022]
|
19
|
Kim WD, Lee YH, Kim MH, Jung SY, Son WC, Yoon SJ, Lee BW. Human monoclonal antibodies against glucagon receptor improve glucose homeostasis by suppression of hepatic glucose output in diet-induced obese mice. PLoS One 2012; 7:e50954. [PMID: 23226550 PMCID: PMC3513295 DOI: 10.1371/journal.pone.0050954] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 10/25/2012] [Indexed: 11/18/2022] Open
Abstract
Aim Glucagon is an essential regulator of hepatic glucose production (HGP), which provides an alternative therapeutic target for managing type 2 diabetes with glucagon antagonists. We studied the effect of a novel human monoclonal antibody against glucagon receptor (GCGR), NPB112, on glucose homeostasis in diet-induced obese (DIO) mice. Methods The glucose-lowering efficacy and safety of NPB112 were investigated in DIO mice with human GCGR for 11 weeks, and a hyperinsulinemic-euglycemic clamp study was conducted to measure HGP. Results Single intraperitoneal injection of NPB112 with 5 mg/kg effectively decreased blood glucose levels in DIO mice for 5 days. A significant reduction in blood glucose was observed in DIO mice treated with NPB112 at a dose ≥5 mg/kg for 6 weeks, and its glucose-lowering effect was dose-dependent. Long-term administration of NPB112 also caused a mild 29% elevation in glucagon level, which was returned to the normal range after discontinuation of treatment. The clamp study showed that DIO mice injected with NPB112 at 5 mg/kg were more insulin sensitive than control mice, indicating amelioration of insulin resistance by treatment with NPB112. DIO mice treated with NPB112 showed a significant improvement in the ability of insulin to suppress HGP, showing a 33% suppression (from 8.3 mg/kg/min to 5.6 mg/kg/min) compared to the 2% suppression (from 9.8 mg/kg/min to 9.6 mg/kg/min) in control mice. In addition, no hypoglycemia or adverse effect was observed during the treatment. Conclusions A novel human monoclonal GCGR antibody, NPB112, effectively lowered the glucose level in diabetic animal models with mild and reversible hyperglucagonemia. Suppression of excess HGP with NPB112 may be a promising therapeutic modality for the treatment of type 2 diabetes.
Collapse
Affiliation(s)
- Wook-Dong Kim
- Department of New Drug Discovery, Neopharm Co., Ltd., Daejeon, Korea
| | - Yong-ho Lee
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
- Department of Medicine, Graduate School Yonsei University, Seoul, Korea
| | - Min-Hee Kim
- Department of New Drug Discovery, Neopharm Co., Ltd., Daejeon, Korea
| | - Sun-Young Jung
- Department of Pathology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Korea
| | - Woo-Chan Son
- Department of Pathology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Korea
| | - Seon-Joo Yoon
- Department of New Drug Discovery, Neopharm Co., Ltd., Daejeon, Korea
- * E-mail: (B-WL); (S-JY)
| | - Byung-Wan Lee
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
- Department of Medicine, Graduate School Yonsei University, Seoul, Korea
- * E-mail: (B-WL); (S-JY)
| |
Collapse
|
20
|
Mu J, Qureshi SA, Brady EJ, Muise ES, Candelore MR, Jiang G, Li Z, Wu MS, Yang X, Dallas-Yang Q, Miller C, Xiong Y, Langdon RB, Parmee ER, Zhang BB. Anti-diabetic efficacy and impact on amino acid metabolism of GRA1, a novel small-molecule glucagon receptor antagonist. PLoS One 2012. [PMID: 23185367 PMCID: PMC3501516 DOI: 10.1371/journal.pone.0049572] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hyperglucagonemia is implicated in the pathophysiology of hyperglycemia. Antagonism of the glucagon receptor (GCGR) thus represents a potential approach to diabetes treatment. Herein we report the characterization of GRA1, a novel small-molecule GCGR antagonist that blocks glucagon binding to the human GCGR (hGCGR) and antagonizes glucagon-induced intracellular accumulation of cAMP with nanomolar potency. GRA1 inhibited glycogenolysis dose-dependently in primary human hepatocytes and in perfused liver from hGCGR mice, a transgenic line of mouse that expresses the hGCGR instead of the murine GCGR. When administered orally to hGCGR mice and rhesus monkeys, GRA1 blocked hyperglycemic responses to exogenous glucagon. In several murine models of diabetes, acute and chronic dosing with GRA1 significantly reduced blood glucose concentrations and moderately increased plasma glucagon and glucagon-like peptide-1. Combination of GRA1 with a dipeptidyl peptidase-4 inhibitor had an additive antihyperglycemic effect in diabetic mice. Hepatic gene-expression profiling in monkeys treated with GRA1 revealed down-regulation of numerous genes involved in amino acid catabolism, an effect that was paralleled by increased amino acid levels in the circulation. In summary, GRA1 is a potent glucagon receptor antagonist with strong antihyperglycemic efficacy in preclinical models and prominent effects on hepatic gene-expression related to amino acid metabolism.
Collapse
Affiliation(s)
- James Mu
- Discovery and Preclinical Sciences, Merck Research Laboratories, Merck Sharp & Dohme Corp., Whitehouse Station, New Jersey, United States of America.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Cho YM, Merchant CE, Kieffer TJ. Targeting the glucagon receptor family for diabetes and obesity therapy. Pharmacol Ther 2012; 135:247-78. [DOI: 10.1016/j.pharmthera.2012.05.009] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 05/15/2012] [Indexed: 12/11/2022]
|
22
|
Xiong Y, Guo J, Candelore MR, Liang R, Miller C, Dallas-Yang Q, Jiang G, McCann PE, Qureshi SA, Tong X, Xu SS, Shang J, Vincent SH, Tota LM, Wright MJ, Yang X, Zhang BB, Tata JR, Parmee ER. Discovery of a novel glucagon receptor antagonist N-[(4-{(1S)-1-[3-(3, 5-dichlorophenyl)-5-(6-methoxynaphthalen-2-yl)-1H-pyrazol-1-yl]ethyl}phenyl)carbonyl]-β-alanine (MK-0893) for the treatment of type II diabetes. J Med Chem 2012; 55:6137-48. [PMID: 22708876 DOI: 10.1021/jm300579z] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A potent, selective glucagon receptor antagonist 9m, N-[(4-{(1S)-1-[3-(3,5-dichlorophenyl)-5-(6-methoxynaphthalen-2-yl)-1H-pyrazol-1-yl]ethyl}phenyl)carbonyl]-β-alanine, was discovered by optimization of a previously identified lead. Compound 9m is a reversible and competitive antagonist with high binding affinity (IC(50) of 6.6 nM) and functional cAMP activity (IC(50) of 15.7 nM). It is selective for glucagon receptor relative to other family B GPCRs, showing IC(50) values of 1020 nM for GIPR, 9200 nM for PAC1, and >10000 nM for GLP-1R, VPAC1, and VPAC2. Compound 9m blunted glucagon-induced glucose elevation in hGCGR mice and rhesus monkeys. It also lowered ambient glucose levels in both acute and chronic mouse models: in hGCGR ob/ob mice it reduced glucose (AUC 0-6 h) by 32% and 39% at 3 and 10 mpk single doses, respectively. In hGCGR mice on a high fat diet, compound 9m at 3, and 10 mpk po in feed lowered blood glucose levels by 89% and 94% at day 10, respectively, relative to the difference between the vehicle control and lean hGCGR mice. On the basis of its favorable biological and DMPK properties, compound 9m (MK-0893) was selected for further preclinical and clinical evaluations.
Collapse
Affiliation(s)
- Yusheng Xiong
- Discovery and Preclinical Sciences, Merck Research Laboratories, Rahway, NJ 07065, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Cryer PE. Minireview: Glucagon in the pathogenesis of hypoglycemia and hyperglycemia in diabetes. Endocrinology 2012; 153:1039-48. [PMID: 22166985 PMCID: PMC3281526 DOI: 10.1210/en.2011-1499] [Citation(s) in RCA: 167] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 11/22/2011] [Indexed: 01/22/2023]
Abstract
Pancreatic islet α-cell glucagon secretion is critically dependent on pancreatic islet β-cell insulin secretion. Normally, a decrease in the plasma glucose concentration causes a decrease in β-cell insulin secretion that signals an increase in α-cell glucagon secretion during hypoglycemia. In contrast, an increase in the plasma glucose concentration, among other stimuli, causes an increase in β-cell insulin secretion that signals a decrease, or at least no change, in α-cell glucagon secretion after a meal. In absolute endogenous insulin deficiency (i.e. in type 1 diabetes and in advanced type 2 diabetes), however, β-cell failure results in no decrease in β-cell insulin secretion and thus no increase in α-cell glucagon secretion during hypoglycemia and no increase in β-cell insulin secretion and thus an increase in α-cell glucagon secretion after a meal. In type 1 diabetes and advanced type 2 diabetes, the absence of an increment in glucagon secretion, in the setting of an absent decrement in insulin secretion and an attenuated increment in sympathoadrenal activity, in response to falling plasma glucose concentrations plays a key role in the pathogenesis of iatrogenic hypoglycemia. In addition, there is increasing evidence that, in the aggregate, suggests that relative hyperglucagonemia, in the setting of deficient insulin secretion, plays a role in the pathogenesis of hyperglycemia in diabetes. If so, abnormal glucagon secretion is involved in the pathogenesis of both hypoglycemia and hyperglycemia in diabetes.
Collapse
Affiliation(s)
- Philip E Cryer
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University, St. Louis, Missouri 63110, USA.
| |
Collapse
|
24
|
Unger RH, Cherrington AD. Glucagonocentric restructuring of diabetes: a pathophysiologic and therapeutic makeover. J Clin Invest 2012; 122:4-12. [PMID: 22214853 DOI: 10.1172/jci60016] [Citation(s) in RCA: 497] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The hormone glucagon has long been dismissed as a minor contributor to metabolic disease. Here we propose that glucagon excess, rather than insulin deficiency, is the sine qua non of diabetes. We base this on the following evidence: (a) glucagon increases hepatic glucose and ketone production, catabolic features present in insulin deficiency; (b) hyperglucagonemia is present in every form of poorly controlled diabetes; (c) the glucagon suppressors leptin and somatostatin suppress all catabolic manifestations of diabetes during total insulin deficiency; (d) total β cell destruction in glucagon receptor-null mice does not cause diabetes; and (e) perfusion of normal pancreas with anti-insulin serum causes marked hyperglucagonemia. From this and other evidence, we conclude that glucose-responsive β cells normally regulate juxtaposed α cells and that without intraislet insulin, unregulated α cells hypersecrete glucagon, which directly causes the symptoms of diabetes. This indicates that glucagon suppression or inactivation may provide therapeutic advantages over insulin monotherapy.
Collapse
Affiliation(s)
- Roger H Unger
- Touchstone Center for Diabetes Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8854, USA.
| | | |
Collapse
|
25
|
Bagger JI, Knop FK, Holst JJ, Vilsbøll T. Glucagon antagonism as a potential therapeutic target in type 2 diabetes. Diabetes Obes Metab 2011; 13:965-71. [PMID: 21615669 DOI: 10.1111/j.1463-1326.2011.01427.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Glucagon is a hormone secreted from the alpha cells of the pancreatic islets. Through its effect on hepatic glucose production (HGP), glucagon plays a central role in the regulation of glucose homeostasis. In patients with type 2 diabetes mellitus (T2DM), abnormal regulation of glucagon secretion has been implicated in the development of fasting and postprandial hyperglycaemia. Therefore, new therapeutic agents based on antagonizing glucagon action, and hence blockade of glucagon-induced HGP, could be effective in lowering both fasting and postprandial hyperglycaemia in patients with T2DM. This review focuses on the mechanism of action, safety and efficacy of glucagon antagonists in the treatment of T2DM and discusses the challenges associated with this new potential antidiabetic treatment modality.
Collapse
Affiliation(s)
- J I Bagger
- Diabetes Research Division, Department of Internal Medicine F, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | | | | | | |
Collapse
|
26
|
Mu J, Jiang G, Brady E, Dallas-Yang Q, Liu F, Woods J, Zycband E, Wright M, Li Z, Lu K, Zhu L, Shen X, Sinharoy R, Candelore ML, Qureshi SA, Shen DM, Zhang F, Parmee ER, Zhang BB. Chronic treatment with a glucagon receptor antagonist lowers glucose and moderately raises circulating glucagon and glucagon-like peptide 1 without severe alpha cell hypertrophy in diet-induced obese mice. Diabetologia 2011; 54:2381-91. [PMID: 21695571 DOI: 10.1007/s00125-011-2217-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 05/03/2011] [Indexed: 11/25/2022]
Abstract
AIMS/HYPOTHESIS Antagonism of the glucagon receptor (GCGR) represents a potential approach for treating diabetes. Cpd-A, a potent and selective GCGR antagonist (GRA) was studied in preclinical models to assess its effects on alpha cells. METHODS Studies were conducted with Cpd-A to examine the effects on glucose-lowering efficacy, its effects in combination with a dipeptidyl peptidase-4 (DPP-4) inhibitor, and the extent and reversibility of alpha cell hypertrophy associated with GCGR antagonism in mouse models. RESULTS Chronic treatment with Cpd-A resulted in effective and sustained glucose lowering in mouse models in which endogenous murine Gcgr was replaced with human GCGR (hGCGR). Treatment with Cpd-A also led to stable, moderate elevations in both glucagon and glucagon-like peptide 1 (GLP-1) levels, which were completely reversible and not associated with a hyperglycaemic overshoot following termination of treatment. When combined with a DPP-4 inhibitor, Cpd-A led to additional improvement of glycaemic control correlated with elevated active GLP-1 levels after glucose challenge. In contrast to Gcgr-knockout mice in which alpha cell hypertrophy was detected, chronic treatment with Cpd-A in obese hGCGR mice did not result in gross morphological changes in pancreatic tissue. CONCLUSIONS/INTERPRETATION A GRA lowered glucose effectively in diabetic models without significant alpha cell hypertrophy during or following chronic treatment. Treatment with a GRA may represent an effective approach for glycaemic control in patients with type 2 diabetes, which could be further enhanced when combined with DPP-4 inhibitors.
Collapse
Affiliation(s)
- J Mu
- Merck, RY80N-A58, 126 East Lincoln Avenue, Rahway, NJ, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
The increasing prevalence, variable pathogenesis, progressive natural history, and complications of type 2 diabetes emphasise the urgent need for new treatment strategies. Longacting (eg, once weekly) agonists of the glucagon-like-peptide-1 receptor are advanced in development, and they improve prandial insulin secretion, reduce excess glucagon production, and promote satiety. Trials of inhibitors of dipeptidyl peptidase 4, which enhance the effect of endogenous incretin hormones, are also nearing completion. Novel approaches to glycaemic regulation include use of inhibitors of the sodium-glucose cotransporter 2, which increase renal glucose elimination, and inhibitors of 11β-hydroxysteroid dehydrogenase 1, which reduce the glucocorticoid effects in liver and fat. Insulin-releasing glucokinase activators and pancreatic-G-protein-coupled fatty-acid-receptor agonists, glucagon-receptor antagonists, and metabolic inhibitors of hepatic glucose output are being assessed. Early proof of principle has been shown for compounds that enhance and partly mimic insulin action and replicate some effects of bariatric surgery.
Collapse
Affiliation(s)
- Abd A Tahrani
- Centre of Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, UK
| | | | | | | |
Collapse
|
28
|
Shen DM, Lin S, Parmee ER. A survey of small molecule glucagon receptor antagonists from recent patents (2006 – 2010). Expert Opin Ther Pat 2011; 21:1211-40. [DOI: 10.1517/13543776.2011.587001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
29
|
Abstract
OBJECTIVE To determine the role of glucagon action in the metabolic phenotype of untreated insulin deficiency. RESEARCH DESIGN AND METHODS We compared pertinent clinical and metabolic parameters in glucagon receptor-null (Gcgr(-/-)) mice and wild-type (Gcgr(+/+)) controls after equivalent destruction of β-cells. We used a double dose of streptozotocin to maximize β-cell destruction. RESULTS Gcgr(+/+) mice became hyperglycemic (>500 mg/dL), hyperketonemic, polyuric, and cachectic and had to be killed after 6 weeks. Despite comparable β-cell destruction in Gcgr(-/-) mice, none of the foregoing clinical or laboratory manifestations of diabetes appeared. There was marked α-cell hyperplasia and hyperglucagonemia (~1,200 pg/mL), but hepatic phosphorylated cAMP response element binding protein and phosphoenolpyruvate carboxykinase mRNA were profoundly reduced compared with Gcgr(+/+) mice with diabetes--evidence that glucagon action had been effectively blocked. Fasting glucose levels and oral and intraperitoneal glucose tolerance tests were normal. Both fasting and nonfasting free fatty acid levels and nonfasting β-hydroxy butyrate levels were lower. CONCLUSIONS We conclude that blocking glucagon action prevents the deadly metabolic and clinical derangements of type 1 diabetic mice.
Collapse
Affiliation(s)
- Young Lee
- Touchstone Center for Diabetes Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - May-Yun Wang
- Touchstone Center for Diabetes Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Xiu Quan Du
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York
| | - Maureen J. Charron
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York
| | - Roger H. Unger
- Touchstone Center for Diabetes Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- VA North Texas Health Care System, Dallas, Texas
- Corresponding author: Roger H. Unger,
| |
Collapse
|
30
|
Rivera N, Ramnanan CJ, An Z, Farmer T, Smith M, Farmer B, Irimia JM, Snead W, Lautz M, Roach PJ, Cherrington AD. Insulin-induced hypoglycemia increases hepatic sensitivity to glucagon in dogs. J Clin Invest 2010; 120:4425-35. [PMID: 21084754 DOI: 10.1172/jci40919] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 09/29/2010] [Indexed: 02/01/2023] Open
Abstract
In individuals with type 1 diabetes, hypoglycemia is a common consequence of overinsulinization. Under conditions of insulin-induced hypoglycemia, glucagon is the most important stimulus for hepatic glucose production. In contrast, during euglycemia, insulin potently inhibits glucagon's effect on the liver. The first aim of the present study was to determine whether low blood sugar augments glucagon's ability to increase glucose production. Using a conscious catheterized dog model, we found that hypoglycemia increased glucagon's ability to overcome the inhibitory effect of insulin on hepatic glucose production by almost 3-fold, an effect exclusively attributable to marked enhancement of the effect of glucagon on net glycogen breakdown. To investigate the molecular mechanism by which this effect comes about, we analyzed hepatic biopsies from the same animals, and found that hypoglycemia resulted in a decrease in insulin signaling. Furthermore, hypoglycemia and glucagon had an additive effect on the activation of AMPK, which was associated with altered activity of the enzymes of glycogen metabolism.
Collapse
Affiliation(s)
- Noelia Rivera
- Department of Molecular Physiology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Piya MK, Tahrani AA, Barnett AH. Emerging treatment options for type 2 diabetes. Br J Clin Pharmacol 2010; 70:631-44. [PMID: 20831513 PMCID: PMC2997303 DOI: 10.1111/j.1365-2125.2010.03711.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 05/06/2010] [Indexed: 12/25/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is rapidly increasing in prevalence and is a major public health problem. It is a progressive disease which commonly requires multiple pharmacotherapy. Current options for treatment may have undesirable side effects (particularly weight gain and hypoglycaemia) and contraindications, and little effect on disease progression. Incretin based therapy is one of several newer therapies to improve glycaemia and is available in two different forms, dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) agonists. Use of these agents results in a 'glucose-dependant' increase in insulin secretion and glucagon suppression resulting in improved glycaemia with low incidence of hypoglycaemia. DPP-4 inhibitors are oral drugs which are weight neutral, while GLP-1 agonists are injected subcutaneously and help promote weight loss while improving glycaemia. GLP-1 agonists have also been shown to increase beta cell mass in rat models. Bariatric surgery is another option for the obese patient with T2DM, with blood glucose normalizing in over half of the patients following surgery. Other therapies in development for the treatment of T2DM include sodium-glucose transporter 2 (SGLT-2) inhibitors, glucagon receptor antagonists, glucokinase activators and sirtuins. In this article, we will review the various existing and emerging treatment options for T2DM.
Collapse
Affiliation(s)
- Milan K Piya
- Department of Diabetes and Endocrinology, Heart of England NHS Foundation Trust, University of BirminghamBirmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, UK
| | - Abd A Tahrani
- Department of Diabetes and Endocrinology, Heart of England NHS Foundation Trust, University of BirminghamBirmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, UK
| | - Anthony H Barnett
- Department of Diabetes and Endocrinology, Heart of England NHS Foundation Trust, University of BirminghamBirmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, UK
| |
Collapse
|
32
|
Paracrinology of islets and the paracrinopathy of diabetes. Proc Natl Acad Sci U S A 2010; 107:16009-12. [PMID: 20798346 DOI: 10.1073/pnas.1006639107] [Citation(s) in RCA: 199] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
New results have brought to light the importance of the regulation of glucagon by β-cells in the development of diabetes. In this perspective, we examine the normal paracrinology of α- and β-cells in nondiabetic pancreatic islets. We propose a Sherringtonian model of coordinated reciprocal secretory responses of these juxtaposed cells that secrete glucagon and insulin, hormones with opposing actions on the liver. As insulin is a powerful inhibitor of glucagon, we propose that within-islet inhibition of α-cells by β-cells creates an insulin-to-glucagon ratio that maintains glycemic stability even in extremes of glucose influx or efflux. By contrast, in type 1 diabetes mellitus, α-cells lack constant action of high insulin levels from juxtaposed β-cells. Replacement with exogenous insulin does not approach paracrine levels of secreted insulin except with high doses that "overinsulinize" the peripheral insulin targets, thereby promoting glycemic volatility. Based on the stable normoglycemia of mice with type 1 diabetes during suppression of glucagon with leptin, we conclude that, in the absence of paracrine regulation of α-cells, tonic inhibition of α-cells improves the dysregulated glucose homeostasis. These results have considerable medical implications, as they suggest new approaches to normalize the extreme volatility of glycemia in diabetic patients.
Collapse
|
33
|
Abstract
Many patients with type 2 diabetes are obese (diabesity), and the two conditions together impose a particularly complex therapeutic challenge. Several differently acting agents are often required at the same time, encouraging development of more single-tablet combinations. Longer-acting (once daily and once weekly) injected agonists of glucagon-like peptide-1 are due to provide additional options to stimulate insulin secretion with weight loss and minimal risk of hypoglycemia. Further, dipeptidyl peptidase-4 inhibitors ("weight-neutral" insulinotropic agents) are also expected. Sodium-glucose cotransporter 2 inhibitors offer a new option to reduce hyperglycemia and facilitate weight loss by increasing the elimination of glucose in the urine. Selective peroxisome proliferator-activated receptor modulators are being studied to produce compounds with desired effects. Many other agents with antidiabetic and antiobesity activity are progressing in clinical development.
Collapse
Affiliation(s)
- Clifford J Bailey
- Life and Health Sciences, Aston University, Aston Street, Aston Triangle, Birmingham B4 7ET, UK.
| |
Collapse
|
34
|
Fischer AJ, Ritchey ER, Scott MA, Wynne A. Bullwhip neurons in the retina regulate the size and shape of the eye. Dev Biol 2008; 317:196-212. [PMID: 18358467 DOI: 10.1016/j.ydbio.2008.02.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 02/04/2008] [Accepted: 02/08/2008] [Indexed: 02/07/2023]
Abstract
Bullwhip and mini-bullwhip cells are unconventional types of retinal neurons that utilize the neuropeptides glucagon, glucagon-like peptide 1 (GLP1) and substance P. These cells have been implicated in regulating the proliferation of neural progenitors in the circumferential marginal zone (CMZ) of the chicken retina. The purpose of this study was to investigate the roles of the bullwhip cells in regulating ocular size and shape. We found that intravitreal delivery of colchicine at postnatal day 7 destroys the vast majority (approximately 98%) of the bullwhip and mini-bullwhip cells and their peptidergic terminals that are concentrated in the CMZ near the equator of the eye. Interestingly, colchicine-treatment resulted in excessive ocular growth that involved the expansion of equatorial diameter, but not axial length. Intraocular injections of glucagon completely prevented the equatorial expansion that occurs with colchicine-treatment. In eyes with undamaged retinas, exogenous glucagon suppressed equatorial eye growth, whereas glucagon receptor antagonists caused excessive equatorial growth. Furthermore, visual stimuli that increase or decrease rates of ocular growth caused a down- or up-regulation, respectively, of the immediate early gene Egr1 in the bullwhip cells; indicating that the activity of the bullwhip cells is regulated by growth-guiding visual cues. We found that the glucagon receptor was expressed by cells in the fibrous and cartilaginous sclera in equatorial regions of the eye. Taken together, these findings suggest that glucagon peptide released from the terminals of the bullwhip and mini-bullwhip cells regulates the growth of the equatorial sclera in a vision-dependent manner. Although the bullwhip and mini-bullwhip cells are not abundant, less than 1000 cells per retina, their influence on the development of the eye is substantial and includes vision-guided ocular growth.
Collapse
Affiliation(s)
- Andy J Fischer
- Department of Neuroscience, College of Medicine, Columbus, OH 43210-1239, USA.
| | | | | | | |
Collapse
|
35
|
Abstract
Type-2 diabetes is associated with impaired glucose clearance by the liver in the postprandial state, and with elevated glucose production in the post-absorptive state. New targets within the liver are currently being investigated for development of antihyperglycaemic drugs for type-2 diabetes. They include glucokinase, which catalyses the first step in glucose metabolism, the glucagon receptor, and enzymes of gluconeogenesis and/or glycogenolysis such as glucose 6-phosphatase, fructose 1,6-bisphosphatase and glycogen phosphorylase. Preclinical studies with candidate drugs on animal models or cell-based assays suggest that these targets have the potential for pharmacological glycaemic control. Data from clinical studies is awaited. Further work is required for better understanding of the implications of targeting these sites in terms of possible side-effects or tachyphylaxis. The advantage of combined targeting of two or more sites within the liver for minimizing side-effects and tachyphylaxis caused by single-site targeting is discussed.
Collapse
Affiliation(s)
- Loranne Agius
- Institute of Cellular Medicine, School of Clinical Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
| |
Collapse
|
36
|
Winzell MS, Brand CL, Wierup N, Sidelmann UG, Sundler F, Nishimura E, Ahrén B. Glucagon receptor antagonism improves islet function in mice with insulin resistance induced by a high-fat diet. Diabetologia 2007; 50:1453-62. [PMID: 17479245 DOI: 10.1007/s00125-007-0675-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 03/05/2007] [Indexed: 12/12/2022]
Abstract
AIMS/HYPOTHESIS Increased glucagon secretion predicts deterioration of glucose tolerance, and high glucagon levels contribute to hyperglycaemia in type 2 diabetes. Inhibition of glucagon action may therefore be a potential novel target to reduce hyperglycaemia. Here, we investigated whether chronic treatment with a glucagon receptor antagonist (GRA) improves islet dysfunction in female mice on a high-fat diet (HFD). MATERIALS AND METHODS After 8 weeks of HFD, mice were treated with a small molecule GRA (300 mg/kg, gavage once daily) for up to 30 days. Insulin secretion was studied after oral and intravenous administration of glucose and glucagon secretion after intravenous arginine. Islet morphology was examined and insulin secretion and glucose oxidation were measured in isolated islets. RESULTS Fasting plasma glucose levels were reduced by GRA (6.0 +/- 0.2 vs 7.4 +/- 0.5 mmol/l; p = 0.017). The acute insulin response to intravenous glucose was augmented (1,300 +/- 110 vs 790 +/- 64 pmol/l; p < 0.001). The early insulin response to oral glucose was reduced in mice on HFD + GRA (1,890 +/- 160 vs 3,040 +/- 420 pmol/l; p = 0.012), but glucose excursions were improved. Intravenous arginine significantly increased the acute glucagon response (129 +/- 12 vs 36 +/- 6 ng/l in controls; p < 0.01), notably without affecting plasma glucose. GRA caused a modest increase in alpha cell mass, while beta cell mass was similar to that in mice on HFD + vehicle. Isolated islets displayed improved glucose-stimulated insulin secretion after GRA treatment (0.061 +/- 0.007 vs 0.030 +/- 0.004 pmol islet(-1) h(-1) at 16.7 mmol/l glucose; p < 0.001), without affecting islet glucose oxidation. CONCLUSIONS/INTERPRETATION Chronic glucagon receptor antagonism in HFD-fed mice improves islet sensitivity to glucose and increases insulin secretion, suggesting improvement of key defects underlying impaired glucose tolerance and type 2 diabetes.
Collapse
Affiliation(s)
- M Sörhede Winzell
- Department of Clinical Sciences, Lund, Division of Medicine, BMC, B11, Lund University, 221 84, Lund, Sweden.
| | | | | | | | | | | | | |
Collapse
|