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Xie C, Alkhouri N, Elfeki MA. Role of incretins and glucagon receptor agonists in metabolic dysfunction-associated steatotic liver disease: Opportunities and challenges. World J Hepatol 2024; 16:731-750. [PMID: 38818288 PMCID: PMC11135259 DOI: 10.4254/wjh.v16.i5.731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 02/18/2024] [Accepted: 04/03/2024] [Indexed: 05/22/2024] Open
Abstract
Metabolic dysfunction-associated steatotic liver disease (MASLD) has become the most common chronic liver disease worldwide, paralleling the rising pandemic of obesity and type 2 diabetes. Due to the growing global health burden and complex pathogenesis of MASLD, a multifaceted and innovative therapeutic approach is needed. Incretin receptor agonists, which were initially developed for diabetes management, have emerged as promising candidates for MASLD treatment. This review describes the pathophysiological mechanisms and action sites of three major classes of incretin/glucagon receptor agonists: glucagon-like peptide-1 receptor agonists, glucose-dependent insulinotropic polypeptide receptor agonists, and glucagon receptor agonists. Incretins and glucagon directly or indirectly impact various organs, including the liver, brain, pancreas, gastrointestinal tract, and adipose tissue. Thus, these agents significantly improve glycemic control and weight management and mitigate MASLD pathogenesis. Importantly, this study provides a summary of clinical trials analyzing the effectiveness and safety of incretin receptor agonists in MASLD management and provides an in-depth analysis highlighting their beneficial effects on improving liver function, hepatic steatosis, and intrahepatic inflammation. There are emerging challenges associated with the use of these medications in the real world, particularly adverse events, drug-drug interactions, and barriers to access, which are discussed in detail. Additionally, this review highlights the evolving role of incretin receptor agonists in MASLD management and suggests future research directions.
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Affiliation(s)
- Chencheng Xie
- Department of Internal Medicine, University of South Dakota Sanford School of Medicine, Sioux Falls, SD 57105, United States
- Department of Hepatology, Avera Mckennan University Hospital and Transplant Institute, Sioux Falls, SD 57105, United States
| | - Naim Alkhouri
- Department of Hepatology, Arizona Liver Health, Chandler, AZ 85712, United States
| | - Mohamed A Elfeki
- Department of Internal Medicine, University of South Dakota Sanford School of Medicine, Sioux Falls, SD 57105, United States
- Department of Hepatology, Avera McKennan University Hospital and Transplant Institute, Sioux Falls, SD 57105, United States.
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2
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Caruso I, Marrano N, Biondi G, Genchi VA, D'Oria R, Sorice GP, Perrini S, Cignarelli A, Natalicchio A, Laviola L, Giorgino F. Glucagon in type 2 diabetes: Friend or foe? Diabetes Metab Res Rev 2023; 39:e3609. [PMID: 36637256 DOI: 10.1002/dmrr.3609] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 12/02/2022] [Accepted: 12/30/2022] [Indexed: 01/14/2023]
Abstract
Hyperglucagonemia is one of the 'ominous' eight factors underlying the pathogenesis of type 2 diabetes (T2D). Glucagon is a peptide hormone involved in maintaining glucose homoeostasis by increasing hepatic glucose output to counterbalance insulin action. Long neglected, the introduction of dual and triple agonists exploiting glucagon signalling pathways has rekindled the interest in this hormone beyond its classic effect on glycaemia. Glucagon can promote weight loss by regulating food intake, energy expenditure, and brown and white adipose tissue functions through mechanisms still to be fully elucidated, thus its role in T2D pathogenesis should be further investigated. Moreover, the role of glucagon in the development of T2D micro- and macro-vascular complications is elusive. Mounting evidence suggests its beneficial effect in non-alcoholic fatty liver disease, while few studies postulated its favourable role in peripheral neuropathy and retinopathy. Contrarily, glucagon receptor agonism might induce renal changes resembling diabetic nephropathy, and data concerning glucagon actions on the cardiovascular system are conflicting. This review aims to summarise the available findings on the role of glucagon in the pathogenesis of T2D and its complications. Further experimental and clinical data are warranted to better understand the implications of glucagon signalling modulation with new antidiabetic drugs.
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Affiliation(s)
- Irene Caruso
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Nicola Marrano
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Giuseppina Biondi
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Valentina Annamaria Genchi
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Rossella D'Oria
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Gian Pio Sorice
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Sebastio Perrini
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Angelo Cignarelli
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Annalisa Natalicchio
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Luigi Laviola
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Francesco Giorgino
- Department of Precision and Regenerative Medicine and Ionian Area, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
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3
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Story LH, Wilson LM. New Developments in Glucagon Treatment for Hypoglycemia. Drugs 2022; 82:1179-1191. [PMID: 35932416 DOI: 10.1007/s40265-022-01754-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2022] [Indexed: 11/28/2022]
Abstract
Glucagon is essential for endogenous glucose regulation along with the paired hormone, insulin. Unlike insulin, pharmaceutical use of glucagon has been limited due to the unstable nature of the peptide. Glucagon has the potential to address hypoglycemia as a major limiting factor in the treatment of diabetes, which remains very common in the type 1 and type 2 diabetes. Recent developments are poised to change this paradigm and expand the use of glucagon for people with diabetes. Glucagon emergency kits have major limitations for their use in treating severe hypoglycemia. A complicated reconstitution and injection process often results in incomplete or aborted administration. New preparations include intranasal glucagon with an easy-to-use and needle-free nasal applicator as well as two stable liquid formulations in pre-filled injection devices. These may ease the burden of severe hypoglycemia treatment. The liquid preparations may also have a role in the treatment of non-severe hypoglycemia. Despite potential benefits of expanded use of glucagon, undesirable side effects (nausea, vomiting), cost, and complexity of adding another medication may limit real-world use. Additionally, more long-term safety and outcome data are needed before widespread, frequent use of glucagon is recommended by providers.
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Affiliation(s)
- LesleAnn Hayward Story
- Division of Endocrinology, Harold Schnitzer Diabetes Health Center, Oregon Health & Science University, Portland, OR, USA
| | - Leah M Wilson
- Division of Endocrinology, Harold Schnitzer Diabetes Health Center, Oregon Health & Science University, Portland, OR, USA.
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4
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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] [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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5
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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] [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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6
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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] [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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7
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Lee JY, Lee M, Lee JY, Bae J, Shin E, Lee YH, Lee BW, Kang ES, Cha BS. Ipragliflozin, an SGLT2 Inhibitor, Ameliorates High-Fat Diet-Induced Metabolic Changes by Upregulating Energy Expenditure through Activation of the AMPK/ SIRT1 Pathway. Diabetes Metab J 2021; 45:921-932. [PMID: 33611885 PMCID: PMC8640151 DOI: 10.4093/dmj.2020.0187] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 08/19/2020] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Sodium-glucose co-transporter 2 (SGLT2) inhibitors are a new class of antidiabetic drugs that exhibit multiple extraglycemic effects. However, there are conflicting results regarding the effects of SGLT2 inhibition on energy expenditure and thermogenesis. Therefore, we investigated the effect of ipragliflozin (a selective SGLT2 inhibitor) on energy metabolism. METHODS Six-week-old male 129S6/Sv mice with a high propensity for adipose tissue browning were randomly assigned to three groups: normal chow control, 60% high-fat diet (HFD)-fed control, and 60% HFD-fed ipragliflozin-treated groups. The administration of diet and medication was continued for 16 weeks. RESULTS The HFD-fed mice became obese and developed hepatic steatosis and adipose tissue hypertrophy, but their random glucose levels were within the normal ranges; these features are similar to the metabolic features of a prediabetic condition. Ipragliflozin treatment markedly attenuated HFD-induced hepatic steatosis and reduced the size of hypertrophied adipocytes to that of smaller adipocytes. In the ipragliflozin treatment group, uncoupling protein 1 (Ucp1) and other thermogenesis-related genes were significantly upregulated in the visceral and subcutaneous adipose tissue, and fatty acid oxidation was increased in the brown adipose tissue. These effects were associated with a significant reduction in the insulin-to-glucagon ratio and the activation of the AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1) pathway in the liver and adipose tissue. CONCLUSION SGLT2 inhibition by ipragliflozin showed beneficial metabolic effects in 129S6/Sv mice with HFD-induced obesity that mimics prediabetic conditions. Our data suggest that SGLT2 inhibitors, through their upregulation of energy expenditure, may have therapeutic potential in prediabetic obesity.
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Affiliation(s)
- Ji-Yeon Lee
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Minyoung Lee
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Ji Young Lee
- Department of Molecular, Cellular and Cancer Biology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Korea
- Institute of Endocrine Research, Yonsei University College of Medicine, Seoul, Korea
| | - Jaehyun Bae
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Eugene Shin
- Institute of Endocrine Research, Yonsei University College of Medicine, Seoul, Korea
| | - Yong-ho Lee
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
- Institute of Endocrine Research, Yonsei University College of Medicine, Seoul, Korea
| | - Byung-Wan Lee
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
- Institute of Endocrine Research, Yonsei University College of Medicine, Seoul, Korea
| | - Eun Seok Kang
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
- Institute of Endocrine Research, Yonsei University College of Medicine, Seoul, Korea
| | - Bong-Soo Cha
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
- Institute of Endocrine Research, Yonsei University College of Medicine, Seoul, Korea
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8
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Hope DCD, Vincent ML, Tan TMM. Striking the Balance: GLP-1/Glucagon Co-Agonism as a Treatment Strategy for Obesity. Front Endocrinol (Lausanne) 2021; 12:735019. [PMID: 34566894 PMCID: PMC8457634 DOI: 10.3389/fendo.2021.735019] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/18/2021] [Indexed: 12/24/2022] Open
Abstract
Obesity and Type 2 diabetes represent global health challenges, and there is an unmet need for long-lasting and effective pharmacotherapies. Although long-acting glucagon-like peptide-1 (GLP-1) analogues are now in routine use for diabetes and are now being utilised for obesity per se, the need for ever better treatments has driven the development of co-agonists, with the theoretical advantages of improved efficacy by targeting multiple pathways and reduced adverse effects. In this review, we highlight the past and present progress in our understanding and development of treatments based on GLP-1/glucagon co-agonism. We also reflect on the divergent effects of varying the GLP-1:glucagon activity and ratio in the context of pre-clinical and human clinical trial findings. In particular, the multiple metabolic actions of glucagon highlight the importance of understanding the contributions of individual hormone action to inform the safe, effective and tailored use of GLP-1/glucagon co-agonists to target weight loss and metabolic disease in the future.
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Affiliation(s)
| | | | - Tricia 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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9
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Reinisch I, Schreiber R, Prokesch A. Regulation of thermogenic adipocytes during fasting and cold. Mol Cell Endocrinol 2020; 512:110869. [PMID: 32439414 DOI: 10.1016/j.mce.2020.110869] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/13/2022]
Abstract
Cold exposure activates brown and brown-like adipocytes that dissipate large amounts of glucose and fatty acids via uncoupling protein 1 (UCP1) to drive non-shivering thermogenesis (NST). Evidence for the existence of these thermogenic adipocytes in adult humans gave rise to a renaissance in research on brown adipose tissue, establishing it as linchpin of energy homeostasis and metabolic health. Besides low ambient temperature, shortage or excess of food affect thermoregulation. Upon high caloric meals thermogenic adipocytes burn excess calories and maintain energy balance. In contrast, in conditions of nutrient deprivation, counter-regulatory mechanisms prevent thermogenic adipocytes from "wasting" energy substrates that need to be conserved. In this review, we discuss cell-autonomous mechanisms, metabolites, and hormones that modify NST in response to nutrient fluctuations. In particular, we focus on how thermogenic adipocytes balance thermogenesis with systemic energy homeostasis during fasting periods.
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Affiliation(s)
- Isabel Reinisch
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center for Cell Signaling, Metabolism & Aging, Medical University of Graz, 8010, Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, 8010, Graz, Austria
| | - Andreas Prokesch
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center for Cell Signaling, Metabolism & Aging, Medical University of Graz, 8010, Graz, Austria; BioTechMed-Graz, 8010, Graz, Austria.
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10
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Kleinert M, Sachs S, Habegger KM, Hofmann SM, Müller TD. Glucagon Regulation of Energy Expenditure. Int J Mol Sci 2019; 20:ijms20215407. [PMID: 31671603 PMCID: PMC6862306 DOI: 10.3390/ijms20215407] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/23/2019] [Accepted: 10/24/2019] [Indexed: 02/07/2023] Open
Abstract
Glucagon's ability to increase energy expenditure has been known for more than 60 years, yet the mechanisms underlining glucagon's thermogenic effect still remain largely elusive. Over the last years, significant efforts were directed to unravel the physiological and cellular underpinnings of how glucagon regulates energy expenditure. In this review, we summarize the current knowledge on how glucagon regulates systems metabolism with a special emphasis on its acute and chronic thermogenic effects.
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Affiliation(s)
- Maximilian Kleinert
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Centre Munich, Ingolstädter Landstraße 1, 85764 Oberschleißheim, Germany.
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, 2100 Copenhagen, Denmark.
| | - Stephan Sachs
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Centre Munich, Ingolstädter Landstraße 1, 85764 Oberschleißheim, Germany.
- Division of Metabolic Diseases, Technische Universität München, 85740 Munich, Germany.
| | - Kirk M Habegger
- Department of Medicine-Endocrinology and Comprehensive Diabetes Center, Diabetes and Metabolism, University of Alabama at Birmingham, Birmingham, AL 35899, USA.
| | - Susanna M Hofmann
- Institute for Diabetes and Regeneration, Helmholtz Diabetes Center at Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany.
- German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
- Medizinische Klinik und Poliklinik IV, Klinikum der LMU, 80336 München, Germany.
| | - Timo D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Centre Munich, Ingolstädter Landstraße 1, 85764 Oberschleißheim, Germany.
- German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, 72076 Tübingen, Germany.
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11
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Glucagon Control on Food Intake and Energy Balance. Int J Mol Sci 2019; 20:ijms20163905. [PMID: 31405212 PMCID: PMC6719123 DOI: 10.3390/ijms20163905] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 07/24/2019] [Accepted: 08/08/2019] [Indexed: 12/17/2022] Open
Abstract
Glucagon exerts pleiotropic actions on energy balance and has emerged as an attractive target for the treatment of diabetes and obesity in the last few years. Glucagon reduces body weight and adiposity by suppression of appetite and by modulation of lipid metabolism. Moreover, this hormone promotes weight loss by activation of energy expenditure and thermogenesis. In this review, we cover these metabolic actions elicited by glucagon beyond its canonical regulation of glucose metabolism. In addition, we discuss recent developments of therapeutic approaches in the treatment of obesity and diabetes by dual- and tri-agonist molecules based on combinations of glucagon with other peptides. New strategies using these unimolecular polyagonists targeting the glucagon receptor (GCGR), have become successful approaches to evaluate the multifaceted nature of glucagon signaling in energy balance and metabolic syndrome.
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12
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Smith SB, Sweatt CR, Carstens GE. Supplementary prenatal copper increases plasma triiodothyronine and brown adipose tissue uncoupling protein-1 gene expression but depresses thermogenesis in newborn lambs. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2019; 33:506-514. [PMID: 31208177 PMCID: PMC7054628 DOI: 10.5713/ajas.18.0179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 05/07/2019] [Indexed: 11/27/2022]
Abstract
Objective We tested the hypothesis that increasing dietary copper (Cu) to gravid ewes would enhance brown adipose tissue (BAT) thermogenesis in their offspring. Methods Twin-bearing ewes were assigned on d 70 of gestation to diets containing 3, 10, or 20 ppm dietary Cu (n = 8 per group). Twin lambs were assigned at birth to a cold (6°C) or warm (28°C) environmental chamber for 48 h. Blood was collected from ewes and from lambs and perirenal BAT was collected after 48 h in the environmental chambers. Results Prenatal Cu exposure increased ewe plasma triiodothyronine (T3) and thyroxine concentration (T4) (p < 0.01) but prenatal Cu exposure had no effect on lamb plasma concentrations of T3, T4, glucose, or nonesterified fatty acid concentration (p ≥ 0.08). The high level of prenatal Cu exposure depressed 48-h rectal temperature (p = 0.03). Cold exposure decreased BAT norepinephrine (NE) and increased BAT dopamine (p ≤ 0.01), but prenatal Cu exposure had no effect on BAT cytochrome C oxidase activity or BAT NE or dopamine (p ≥ 0.07). However, BAT of lambs from high-Cu ewes maintained higher uncoupling protein-1 (UCP1) gene expression than BAT of lambs from low- and medium-Cu ewes following warm or cold exposure in environmental chambers (p = 0.02). Cold exposure caused near depletion of BAT lipid by 48 h (p < 0.001), increased BAT cytochrome c oxidase activity (p < 0.01), and depressed plasma fatty acid concentrations (p < 0.001). Conclusion Although prenatal Cu exposure increased BAT UCP1 expression during warm and cold exposure, prenatal cold Cu exposure depressed 48-h rectal temperature. Cold exposure decreased BAT lipid content by over 80% and decreased lamb plasma fatty acid concentration by over 40%, indicating that fuel reserves for thermogenesis were nearly depleted by 48 h of cold exposure.
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Affiliation(s)
- Stephen B Smith
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
| | - Craig R Sweatt
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
| | - Gordon E Carstens
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA
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13
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Beaudry JL, Kaur KD, Varin EM, Baggio LL, Cao X, Mulvihill EE, Stern JH, Campbell JE, Scherer PE, Drucker DJ. The brown adipose tissue glucagon receptor is functional but not essential for control of energy homeostasis in mice. Mol Metab 2019; 22:37-48. [PMID: 30772257 PMCID: PMC6437632 DOI: 10.1016/j.molmet.2019.01.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 02/02/2023] Open
Abstract
Objective Administration of glucagon (GCG) or GCG-containing co-agonists reduces body weight and increases energy expenditure. These actions appear to be transduced by multiple direct and indirect GCG receptor (GCGR)-dependent mechanisms. Although the canonical GCGR is expressed in brown adipose tissue (BAT) the importance of BAT GCGR activity for the physiological control of body weight, or the response to GCG agonism, has not been defined. Methods We studied the mechanisms linking GCG action to acute increases in oxygen consumption using wildtype (WT), Ucp1−/− and Fgf21−/− mice. The importance of basal GCGR expression within the Myf5+ domain for control of body weight, adiposity, glucose and lipid metabolism, food intake, and energy expenditure was examined in GcgrBAT−/− mice housed at room temperature or 4 °C, fed a regular chow diet (RCD) or after a prolonged exposure to high fat diet (HFD). Results Acute GCG administration induced lipolysis and increased the expression of thermogenic genes in BAT cells, whereas knockdown of Gcgr reduced expression of genes related to thermogenesis. GCG increased energy expenditure (measured by oxygen consumption) both in vivo in WT mice and ex vivo in BAT and liver explants. GCG also increased acute energy expenditure in Ucp1−/− mice, but these actions were partially blunted in Ffg21−/− mice. However, acute GCG administration also robustly increased oxygen consumption in GcgrBAT−/− mice. Moreover, body weight, glycemia, lipid metabolism, body temperature, food intake, activity, energy expenditure and adipose tissue gene expression profiles were normal in GcgrBAT−/− mice, either on RCD or HFD, whether studied at room temperature, or chronically housed at 4 °C. Conclusions Exogenous GCG increases oxygen consumption in mice, also evident both in liver and BAT explants ex vivo, through UCP1-independent, FGF21-dependent pathways. Nevertheless, GCGR signaling within BAT is not physiologically essential for control of body weight, whole body energy expenditure, glucose homeostasis, or the adaptive metabolic response to cold or prolonged exposure to an energy dense diet. A functional glucagon receptor is expressed in brown adipose tissue and BAT cells. Glucagon increases energy expenditure in mice, as well as in liver and BAT. Glucagon increases whole body energy expenditure through FGF21-dependent and BAT glucagon receptor-independent pathways. Loss of the BAT glucagon receptor does not impair glucose or energy homeostasis in mice.
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Affiliation(s)
- Jacqueline L Beaudry
- Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada
| | - Kiran Deep Kaur
- Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada
| | - Elodie M Varin
- Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada
| | - Laurie L Baggio
- Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada
| | - Xiemin Cao
- Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada
| | - Erin E Mulvihill
- Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada
| | - Jennifer H Stern
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, USA
| | - Jonathan E Campbell
- Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada
| | - Phillip E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, USA
| | - Daniel J Drucker
- Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Cherry consumption out of season alters lipid and glucose homeostasis in normoweight and cafeteria-fed obese Fischer 344 rats. J Nutr Biochem 2019; 63:72-86. [DOI: 10.1016/j.jnutbio.2018.09.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 07/30/2018] [Accepted: 09/12/2018] [Indexed: 02/06/2023]
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15
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Scott R, Minnion J, Tan T, Bloom SR. Oxyntomodulin analogue increases energy expenditure via the glucagon receptor. Peptides 2018; 104:70-77. [PMID: 29680267 PMCID: PMC5958244 DOI: 10.1016/j.peptides.2018.04.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/03/2018] [Accepted: 04/10/2018] [Indexed: 01/12/2023]
Abstract
The gut hormone oxyntomodulin (OXM) causes weight loss by reducing appetite and increasing energy expenditure. Several analogues are being developed to treat obesity. Exactly how oxyntomodulin works, however, remains controversial. OXM can activate both glucagon and GLP-1 receptors but no specific receptor has been identified. It is thought that the anorectic effect occurs predominantly through GLP-1 receptor activation but, to date, it has not been formally confirmed which receptor is responsible for the increased energy expenditure. We developed OX-SR, a sustained-release OXM analogue. It produces a significant and sustained increase in energy expenditure in rats as measured by indirect calorimetry. We now show that this increase in energy expenditure occurs via activation of the glucagon receptor. Blockade of the GLP-1 receptor with Exendin 9-39 does not block the increase in oxygen consumption caused by OX-SR. However, when activity at the glucagon receptor is lost, there is no increase in energy expenditure. Glucagon receptor activity therefore appears to be essential for OX-SR's effects on energy expenditure. The development of future 'dual agonist' analogues will require careful balancing of GLP-1 and glucagon receptor activities to obtain optimal effects.
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Affiliation(s)
- R Scott
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, United Kingdom.
| | - J Minnion
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, United Kingdom
| | - T Tan
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, United Kingdom
| | - S R Bloom
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN, United Kingdom.
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16
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Pedersen C, Porsgaard T, Thomsen M, Rosenkilde MM, Roed NK. Sustained effect of glucagon on body weight and blood glucose: Assessed by continuous glucose monitoring in diabetic rats. PLoS One 2018; 13:e0194468. [PMID: 29558502 PMCID: PMC5860770 DOI: 10.1371/journal.pone.0194468] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/02/2018] [Indexed: 11/18/2022] Open
Abstract
Insulin is a vital part of diabetes treatment, whereas glucagon is primarily used to treat insulin-induced hypoglycemia. However, glucagon is suggested to have a central role in the regulation of body weight, which would be beneficial for diabetic patients. Since the glucagon effect on blood glucose is known to be transient, it is relevant to investigate the pharmacodynamics of glucagon after repeated dosing. In the present study, we used telemetry to continuously measure blood glucose in streptozotocin induced diabetic Sprague-Dawley rats. This allowed for a more detailed analysis of glucose regulation compared to intermittent blood sampling. In particular, we evaluated the blood glucose-lowering effect of different insulin doses alone, and in combination with a long acting glucagon analog (LAG). We showed how the effect of the LAG accumulated and persisted over time. Furthermore, we found that addition of the LAG decreased body weight without affecting food intake. In a subsequent study, we focused on the glucagon effect on body weight and food intake during equal glycemic control. In order to obtain comparable maximum blood glucose lowering effect to insulin alone, the insulin dose had to be increased four times in combination with 1 nmol/kg of the LAG. In this set-up the LAG prevented further increase in body weight despite the four times higher insulin-dose. However, the body composition was changed. The insulin group increased both lean and fat mass, whereas the group receiving four times insulin in combination with the LAG only significantly increased the fat mass. No differences were observed in food intake, suggesting a direct effect on energy expenditure by glucagon. Surprisingly, we observed decreased levels of FGF21 in plasma compared to insulin treatment alone. With the combination of insulin and the LAG the blood glucose-lowering effect of insulin was prolonged, which could potentially be beneficial in diabetes treatment.
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Affiliation(s)
- Christina Pedersen
- Department of GLP-1 & T2D Biology, Novo Nordisk A/S, Maaloev, Denmark
- Faculty of Health and Medical Sciences, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
| | - Trine Porsgaard
- Department of Insulin Pharmacology, Novo Nordisk A/S, Maaloev, Denmark
| | - Maria Thomsen
- Department of Modelling, Novo Nordisk A/S, Maaloev, Denmark
| | - Mette Marie Rosenkilde
- Faculty of Health and Medical Sciences, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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17
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Polypharmacy through Phage Display: Selection of Glucagon and GLP-1 Receptor Co-agonists from a Phage-Displayed Peptide Library. Sci Rep 2018; 8:585. [PMID: 29330364 PMCID: PMC5766609 DOI: 10.1038/s41598-017-18494-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 11/16/2017] [Indexed: 02/07/2023] Open
Abstract
A promising emerging area for the treatment of obesity and diabetes is combinatorial hormone therapy, where single-molecule peptides are rationally designed to integrate the complementary actions of multiple endogenous metabolically-related hormones. We describe here a proof-of-concept study on developing unimolecular polypharmacy agents through the use of selection methods based on phage-displayed peptide libraries (PDL). Co-agonists of the glucagon (GCG) and GLP-1 receptors were identified from a PDL sequentially selected on GCGR- and GLP1R-overexpressing cells. After two or three rounds of selection, 7.5% of randomly picked clones were GLP1R/GCGR co-agonists, and a further 1.53% were agonists of a single receptor. The phages were sequenced and 35 corresponding peptides were synthesized. 18 peptides were potent co-agonists, 8 of whom showed EC50 ≤ 30 pM on each receptor, comparable to the best rationally designed co-agonists reported in the literature. Based on literature examples, two sequences were engineered to stabilize against dipeptidyl peptidase IV cleavage and prolong the in vivo half-life: the engineered peptides were comparably potent to the parent peptides on both receptors, highlighting the potential use of phage-derived peptides as therapeutic agents. The strategy described here appears of general value for the discovery of optimized polypharmacology paradigms across several metabolically-related hormones.
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18
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Lee MS, Shin Y, Jung S, Kim Y. Effects of epigallocatechin-3-gallate on thermogenesis and mitochondrial biogenesis in brown adipose tissues of diet-induced obese mice. Food Nutr Res 2017; 61:1325307. [PMID: 28659734 PMCID: PMC5475335 DOI: 10.1080/16546628.2017.1325307] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/27/2017] [Indexed: 11/15/2022] Open
Abstract
Background: Epigallocatechin-3-gallate (EGCG) is the major polyphenol in green tea and has been considered a natural agent that can help to reduce the risk of obesity. Objective: The aim of this study was to investigate the effects of EGCG on thermogenesis and mitochondrial biogenesis in brown adipose tissue (BAT) of diet-induced obese mice. Methods: Male C57BL/6J mice were provided a high-fat diet for 8 weeks to induce obesity, following which they were divided into two groups: one on a high-fat control diet and the other on a 0.2% EGCG (w/w)-supplemented high-fat diet for another 8 weeks. Results: The EGCG-supplemented group showed decreased body weight gain, and plasma and liver lipids. EGCG-fed mice exhibited higher body temperature and mitochondrial DNA (mtDNA) content in BAT. The messenger RNA levels of genes related to thermogenesis and mitochondrial biogenesis in BAT were increased by EGCG. Moreover, adenosine monophosphate-activated protein kinase (AMPK) activity in BAT was stimulated by EGCG. Conclusions: The results suggest that EGCG may have anti-obesity properties through BAT thermogenesis and mitochondria biogenesis, which are partially associated with the regulation of genes related to thermogenesis and mitochondria biogenesis, and the increase in mtDNA replication and AMPK activation in BAT of diet-induced obese mice.
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Affiliation(s)
- Mak-Soon Lee
- Department of Nutritional Science and Food Management, Ewha Womans University, Seoul, Republic of Korea
| | - Yoonjin Shin
- Department of Nutritional Science and Food Management, Ewha Womans University, Seoul, Republic of Korea
| | - Sunyoon Jung
- Department of Nutritional Science and Food Management, Ewha Womans University, Seoul, Republic of Korea
| | - Yangha Kim
- Department of Nutritional Science and Food Management, Ewha Womans University, Seoul, Republic of Korea
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19
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Salem V, Izzi‐Engbeaya C, Coello C, Thomas DB, Chambers ES, Comninos AN, Buckley A, Win Z, Al‐Nahhas A, Rabiner EA, Gunn RN, Budge H, Symonds ME, Bloom SR, Tan TM, Dhillo WS. Glucagon increases energy expenditure independently of brown adipose tissue activation in humans. Diabetes Obes Metab 2016; 18:72-81. [PMID: 26434748 PMCID: PMC4710848 DOI: 10.1111/dom.12585] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 08/01/2015] [Accepted: 09/29/2015] [Indexed: 02/06/2023]
Abstract
AIMS To investigate, for a given energy expenditure (EE) rise, the differential effects of glucagon infusion and cold exposure on brown adipose tissue (BAT) activation in humans. METHODS Indirect calorimetry and supraclavicular thermography was performed in 11 healthy male volunteers before and after: cold exposure; glucagon infusion (at 23 °C); and vehicle infusion (at 23 °C). All volunteers underwent (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/CT scanning with cold exposure. Subjects with cold-induced BAT activation on (18)F-FDG PET/CT (n = 8) underwent a randomly allocated second (18)F-FDG PET/CT scan (at 23 °C), either with glucagon infusion (n = 4) or vehicle infusion (n = 4). RESULTS We observed that EE increased by 14% after cold exposure and by 15% after glucagon infusion (50 ng/kg/min; p < 0.05 vs control for both). Cold exposure produced an increase in neck temperature (+0.44 °C; p < 0.001 vs control), but glucagon infusion did not alter neck temperature. In subjects with a cold-induced increase in the metabolic activity of supraclavicular BAT on (18)F-FDG PET/CT, a significant rise in the metabolic activity of BAT after glucagon infusion was not detected. Cold exposure increased sympathetic activation, as measured by circulating norepinephrine levels, but glucagon infusion did not. CONCLUSIONS Glucagon increases EE by a similar magnitude compared with cold activation, but independently of BAT thermogenesis. This finding is of importance for the development of safe treatments for obesity through upregulation of EE.
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Affiliation(s)
- V. Salem
- Section of Investigative MedicineHammersmith Hospital, Imperial College LondonLondonUK
| | - C. Izzi‐Engbeaya
- Section of Investigative MedicineHammersmith Hospital, Imperial College LondonLondonUK
| | - C. Coello
- Imanova Centre for Imaging Sciences, Hammersmith HospitalLondonUK
| | - D. B. Thomas
- Department of ComputingImperial College LondonLondonUK
| | - E. S. Chambers
- Section of Investigative MedicineHammersmith Hospital, Imperial College LondonLondonUK
| | - A. N. Comninos
- Section of Investigative MedicineHammersmith Hospital, Imperial College LondonLondonUK
| | - A. Buckley
- Section of Investigative MedicineHammersmith Hospital, Imperial College LondonLondonUK
| | - Z. Win
- Department of RadiologyImperial College NHS Healthcare TrustLondonUK
| | - A. Al‐Nahhas
- Department of RadiologyImperial College NHS Healthcare TrustLondonUK
| | - E. A. Rabiner
- Imanova Centre for Imaging Sciences, Hammersmith HospitalLondonUK
- Centre for Neuroimaging SciencesKing's CollegeLondonUK
| | - R. N. Gunn
- Imanova Centre for Imaging Sciences, Hammersmith HospitalLondonUK
- Division of Brain SciencesImperial College LondonLondonUK
| | - H. Budge
- Early Life Research Group, Academic Division of Child Health, Obsterics and Gynaecology, School of Medicine, Queen's Medical Centre, University HospitalThe University of NottinghamNottinghamUK
| | - M. E. Symonds
- Early Life Research Group, Academic Division of Child Health, Obsterics and Gynaecology, School of Medicine, Queen's Medical Centre, University HospitalThe University of NottinghamNottinghamUK
| | - S. R. Bloom
- Section of Investigative MedicineHammersmith Hospital, Imperial College LondonLondonUK
| | - T. M. Tan
- Section of Investigative MedicineHammersmith Hospital, Imperial College LondonLondonUK
| | - W. S. Dhillo
- Section of Investigative MedicineHammersmith Hospital, Imperial College LondonLondonUK
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20
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Morrison SF, Madden CJ. Central nervous system regulation of brown adipose tissue. Compr Physiol 2015; 4:1677-713. [PMID: 25428857 DOI: 10.1002/cphy.c140013] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Thermogenesis, the production of heat energy, in brown adipose tissue is a significant component of the homeostatic repertoire to maintain body temperature during the challenge of low environmental temperature in many species from mouse to man and plays a key role in elevating body temperature during the febrile response to infection. The sympathetic neural outflow determining brown adipose tissue (BAT) thermogenesis is regulated by neural networks in the CNS which increase BAT sympathetic nerve activity in response to cutaneous and deep body thermoreceptor signals. Many behavioral states, including wakefulness, immunologic responses, and stress, are characterized by elevations in core body temperature to which central command-driven BAT activation makes a significant contribution. Since energy consumption during BAT thermogenesis involves oxidation of lipid and glucose fuel molecules, the CNS network driving cold-defensive and behavioral state-related BAT activation is strongly influenced by signals reflecting the short- and long-term availability of the fuel molecules essential for BAT metabolism and, in turn, the regulation of BAT thermogenesis in response to metabolic signals can contribute to energy balance, regulation of body adipose stores and glucose utilization. This review summarizes our understanding of the functional organization and neurochemical influences within the CNS networks that modulate the level of BAT sympathetic nerve activity to produce the thermoregulatory and metabolic alterations in BAT thermogenesis and BAT energy expenditure that contribute to overall energy homeostasis and the autonomic support of behavior.
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Affiliation(s)
- Shaun F Morrison
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon
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21
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Abstract
Glucagon is secreted from islet α cells and controls blood levels of glucose in the fasting state. Impaired glucagon secretion predisposes some patients with type 1 diabetes mellitus (T1DM) to hypoglycaemia; whereas hyperglycaemia in patients with T1DM or type 2 diabetes mellitus (T2DM) is often associated with hyperglucagonaemia. Hence, therapeutic strategies to safely achieve euglycaemia in patients with diabetes mellitus now encompass bihormonal approaches to simultaneously deliver insulin and glucagon (in patients with T1DM) or reduce excess glucagon action (in patients with T1DM or T2DM). Glucagon also reduces food intake and increases energy expenditure through central and peripheral mechanisms, which suggests that activation of signalling through the glucagon receptor might be useful for controlling body weight. Here, we review new data that is relevant to understanding α-cell biology and glucagon action in the brain, liver, adipose tissue and heart, with attention to normal physiology, as well as conditions associated with dysregulated glucagon action. The feasibility and safety of current and emerging glucagon-based therapies that encompass both gain-of-function and loss-of-function approaches for the treatment of T1DM, T2DM and obesity is discussed in addition to developments, challenges and critical gaps in our knowledge that require additional investigation.
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Affiliation(s)
- Jonathan E Campbell
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, 600 University Avenue, TCP5-1004, Toronto, ON M5G 1X5, Canada
| | - Daniel J Drucker
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, 600 University Avenue, TCP5-1004, Toronto, ON M5G 1X5, Canada
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22
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Lockie SH, Heppner KM, Chaudhary N, Chabenne JR, Morgan DA, Veyrat-Durebex C, Ananthakrishnan G, Rohner-Jeanrenaud F, Drucker DJ, DiMarchi R, Rahmouni K, Oldfield BJ, Tschöp MH, Perez-Tilve D. Direct control of brown adipose tissue thermogenesis by central nervous system glucagon-like peptide-1 receptor signaling. Diabetes 2012; 61:2753-62. [PMID: 22933116 PMCID: PMC3478556 DOI: 10.2337/db11-1556] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We studied interscapular brown adipose tissue (iBAT) activity in wild-type (WT) and glucagon-like peptide 1 receptor (GLP-1R)-deficient mice after the administration of the proglucagon-derived peptides (PGDPs) glucagon-like peptide (GLP-1), glucagon (GCG), and oxyntomodulin (OXM) directly into the brain. Intracerebroventricular injection of PGDPs reduces body weight and increases iBAT thermogenesis. This was independent of changes in feeding and insulin responsiveness but correlated with increased activity of sympathetic fibers innervating brown adipose tissue (BAT). Despite being a GCG receptor agonist, OXM requires GLP-1R activation to induce iBAT thermogenesis. The increase in thermogenesis in WT mice correlates with increased expression of genes upregulated by adrenergic signaling and required for iBAT thermogenesis, including PGC1a and UCP-1. In spite of the increase in iBAT thermogenesis induced by GLP-1R activation in WT mice, Glp1r(-/-) mice exhibit a normal response to cold exposure, demonstrating that endogenous GLP-1R signaling is not essential for appropriate thermogenic response after cold exposure. Our data suggest that the increase in BAT thermogenesis may be an additional mechanism whereby pharmacological GLP-1R activation controls energy balance.
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Affiliation(s)
- Sarah H. Lockie
- Department of Internal Medicine, Metabolic Disease Institute, University of Cincinnati, Cincinnati, Ohio
- Department of Physiology, Monash University, Melbourne, Australia
| | - Kristy M. Heppner
- Department of Internal Medicine, Metabolic Disease Institute, University of Cincinnati, Cincinnati, Ohio
| | - Nilika Chaudhary
- Department of Internal Medicine, Metabolic Disease Institute, University of Cincinnati, Cincinnati, Ohio
| | | | - Donald A. Morgan
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Christelle Veyrat-Durebex
- Department of Internal Medicine, Laboratory of Metabolism, Division of Endocrinology, Diabetology and Nutrition, University of Geneva, Geneva, Switzerland
| | - Gayathri Ananthakrishnan
- Department of Internal Medicine, Metabolic Disease Institute, University of Cincinnati, Cincinnati, Ohio
| | - Françoise Rohner-Jeanrenaud
- Department of Internal Medicine, Laboratory of Metabolism, Division of Endocrinology, Diabetology and Nutrition, University of Geneva, Geneva, Switzerland
| | - Daniel J. Drucker
- Department of Medicine, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Richard DiMarchi
- Department of Chemistry, Indiana University, Bloomington, Indiana
| | - Kamal Rahmouni
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | | | - Matthias H. Tschöp
- Department of Internal Medicine, Metabolic Disease Institute, University of Cincinnati, Cincinnati, Ohio
| | - Diego Perez-Tilve
- Department of Internal Medicine, Metabolic Disease Institute, University of Cincinnati, Cincinnati, Ohio
- Corresponding author: Diego Perez-Tilve,
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Abstract
Glucagon is traditionally thought of as an antihypoglycemic hormone, for example in response to starvation. However, it actually increases energy expenditure and has other actions not in line with protection from hypoglycemia. Furthermore, it is often found to be elevated when glucose is also raised, for example in circumstances of psychological and metabolic stress. These findings seem more in keeping with glucagon having some role as a hormone enhancing the response to stress.
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Affiliation(s)
- B J Jones
- Department of Investigative Medicine, Commonwealth Building, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0HS, United Kingdom
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24
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Habegger KM, Heppner KM, Geary N, Bartness TJ, DiMarchi R, Tschöp MH. The metabolic actions of glucagon revisited. Nat Rev Endocrinol 2010; 6:689-97. [PMID: 20957001 PMCID: PMC3563428 DOI: 10.1038/nrendo.2010.187] [Citation(s) in RCA: 244] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The initial identification of glucagon as a counter-regulatory hormone to insulin revealed this hormone to be of largely singular physiological and pharmacological purpose. Glucagon agonism, however, has also been shown to exert effects on lipid metabolism, energy balance, body adipose tissue mass and food intake. The ability of glucagon to stimulate energy expenditure, along with its hypolipidemic and satiating effects, in particular, make this hormone an attractive pharmaceutical agent for the treatment of dyslipidemia and obesity. Studies that describe novel preclinical applications of glucagon, alone and in concert with glucagon-like peptide 1 agonism, have revealed potential benefits of glucagon agonism in the treatment of the metabolic syndrome. Collectively, these observations challenge us to thoroughly investigate the physiology and therapeutic potential of insulin's long-known opponent.
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Affiliation(s)
- Kirk M Habegger
- Department of Medicine, University of Cincinnati, Metabolic Diseases Institute, Office E-217, 2170 East Galbraith Road, Cincinnati, OH 45237, USA
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A new glucagon and GLP-1 co-agonist eliminates obesity in rodents. Nat Chem Biol 2009; 5:749-57. [PMID: 19597507 DOI: 10.1038/nchembio.209] [Citation(s) in RCA: 450] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Accepted: 07/07/2009] [Indexed: 12/11/2022]
Abstract
We report the efficacy of a new peptide with agonism at the glucagon and GLP-1 receptors that has potent, sustained satiation-inducing and lipolytic effects. Selective chemical modification to glucagon resulted in a loss of specificity, with minimal change to inherent activity. The structural basis for the co-agonism appears to be a combination of local positional interactions and a change in secondary structure. Two co-agonist peptides differing from each other only in their level of glucagon receptor agonism were studied in rodent obesity models. Administration of PEGylated peptides once per week normalized adiposity and glucose tolerance in diet-induced obese mice. Reduction of body weight was achieved by a loss of body fat resulting from decreased food intake and increased energy expenditure. These preclinical studies indicate that when full GLP-1 agonism is augmented with an appropriate degree of glucagon receptor activation, body fat reduction can be substantially enhanced without any overt adverse effects.
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Abstract
Glucose homeostasis is regulated primarily by the opposing actions of insulin and glucagon, hormones that are secreted by pancreatic islets from beta-cells and alpha-cells, respectively. Insulin secretion is increased in response to elevated blood glucose to maintain normoglycemia by stimulating glucose transport in muscle and adipocytes and reducing glucose production by inhibiting gluconeogenesis in the liver. Whereas glucagon secretion is suppressed by hyperglycemia, it is stimulated during hypoglycemia, promoting hepatic glucose production and ultimately raising blood glucose levels. Diabetic hyperglycemia occurs as the result of insufficient insulin secretion from the beta-cells and/or lack of insulin action due to peripheral insulin resistance. Remarkably, excessive secretion of glucagon from the alpha-cells is also a major contributor to the development of diabetic hyperglycemia. Insulin is a physiological suppressor of glucagon secretion; however, at the cellular and molecular levels, how intraislet insulin exerts its suppressive effect on the alpha-cells is not very clear. Although the inhibitory effect of insulin on glucagon gene expression is an important means to regulate glucagon secretion, recent studies suggest that the underlying mechanisms of the intraislet insulin on suppression of glucagon secretion involve the modulation of K(ATP) channel activity and the activation of the GABA-GABA(A) receptor system. Nevertheless, regulation of glucagon secretion is multifactorial and yet to be fully understood.
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Affiliation(s)
- Pritpal Bansal
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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Morales A, Lachuer J, Gélöen A, Georges B, Duchamp C, Barré H. Sympathetic control of glucagon receptor mRNA levels in brown adipose tissue of cold-exposed rats. Mol Cell Biochem 2000; 208:139-42. [PMID: 10939637 DOI: 10.1023/a:1007058525309] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Brown adipose tissue (BAT) is implicated in both cold-induced thermogenesis and regulation of energy expenditure and is mainly controlled by sympathetic innervation. To clarify the permissive and/or complementary roles of glucagon in cold-induced BAT activation, glucagon receptor gene expression and its modulation by sympathetic activity were investigated in rats. One pad of interscapular BAT was surgically denervated while the other pad was sham operated, then rats were either cold-exposed (CE) for 1 week at 4 degrees C or kept near thermoneutrality (25 degrees C, TN). Using a semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay, it was shown that cold exposure decreased (-44%) the relative abundance of BAT glucagon receptor mRNA, an effect which was prevented by unilateral surgical sympathectomy of BAT. The present results show a negative control by sympathetic nervous activity of glucagon receptor gene expression and/or of glucagon receptor mRNA stability in BAT of cold-exposed rats. The down-regulation of glucagon receptor expression during cold exposure does not support a major role of the peptide in the thermogenic control of BAT.
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Affiliation(s)
- A Morales
- Laboratoire de Physiologie des Régulations Energétiques, Cellulaires et Moléculaires, UMR 5578 CNRS-UCB LYON 1, Faculté des Sciences, Villeurbanne, France
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Kotz CM, Grace MK, Briggs J, Levine AS, Billington CJ. Effects of opioid antagonists naloxone and naltrexone on neuropeptide Y-induced feeding and brown fat thermogenesis in the rat. Neural site of action. J Clin Invest 1995; 96:163-70. [PMID: 7615787 PMCID: PMC185185 DOI: 10.1172/jci118017] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Neuropeptide Y administered intracerebroventricularly and into the paraventricular nucleus of the hypothalamus stimulates feeding and decreases brown adipose tissue thermogenesis. Although specific neuropeptide Y antagonists are not yet available, previous studies had shown that the opioid antagonist naloxone blocked neuropeptide Y-induced feeding when both drugs were injected intracerebroventricularly. We wanted to find out if naloxone injected into specific brain sites would block neuropeptide Y effects on feeding and brown fat thermogenesis. Rats were double injected in specific brain sites with neuropeptide Y and either naloxone or naltrexone (a congener of naloxone). Food intake and brown fat measures were assessed. Naloxone or naltrexone in the paraventricular nucleus weakly decreased paraventricular nucleus neuropeptide Y-induced feeding and did not affect neuropeptide Y-induced reductions in brown fat activity. Peripheral naloxone blocked intracerebroventricular neuropeptide Y-induced feeding and brown fat alterations. Fourth ventricular naloxone decreased paraventricular nucleus neuropeptide Y-induced feeding, and naltrexone given into the nucleus of the solitary tract blocked paraventricular nucleus neuropeptide Y-induced alterations in feeding and brown fat. These data indicate that neuropeptide Y in the paraventricular nucleus may act on feeding and brown fat thermogenesis through opioidergic pathways in the nucleus of the solitary tract.
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Affiliation(s)
- C M Kotz
- Department of Food Science and Nutrition, University of Minnesota, Saint Paul 55108, USA
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