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Acreman S, Ma J, Denwood G, Gao R, Tarasov A, Rorsman P, Zhang Q. The endoplasmic reticulum plays a key role in α-cell intracellular Ca 2+ dynamics and glucose-regulated glucagon secretion in mouse islets. iScience 2024; 27:109665. [PMID: 38646167 PMCID: PMC11033163 DOI: 10.1016/j.isci.2024.109665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 02/13/2024] [Accepted: 04/02/2024] [Indexed: 04/23/2024] Open
Abstract
Glucagon is secreted by pancreatic α-cells to counteract hypoglycaemia. How glucose regulates glucagon secretion remains unclear. Here, using mouse islets, we studied the role of transmembrane and endoplasmic reticulum (ER) Ca2+ on intrinsic α-cell glucagon secretion. Blocking isradipine-sensitive L-type voltage-gated Ca2+ (Cav) channels abolished α-cell electrical activity but had little impact on its cytosolic Ca2+ oscillations or low-glucose-stimulated glucagon secretion. In contrast, depleting ER Ca2+ with cyclopiazonic acid or blocking ER Ca2+-releasing ryanodine receptors abolished α-cell glucose sensitivity and low-glucose-stimulated glucagon secretion. ER Ca2+ mobilization in α-cells is regulated by intracellular ATP and likely to be coupled to Ca2+ influx through P/Q-type Cav channels. ω-Agatoxin IVA blocked α-cell ER Ca2+ release and cell exocytosis, but had no additive effect on glucagon secretion when combined with ryanodine. We conclude that glucose regulates glucagon secretion through the control of ER Ca2+ mobilization, a mechanism that can be independent of α-cell electrical activity.
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Affiliation(s)
- Samuel Acreman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK
- Institute of Neuroscience and Physiology, Department of Physiology, Metabolic Research Unit, Sahlgrenska Academy, University of Gothenburg, Box 430, S-405 30 Gothenburg, Sweden
| | - Jinfang Ma
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK
- Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
| | - Geoffrey Denwood
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK
| | - Rui Gao
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK
| | - Andrei Tarasov
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK
- Institute of Neuroscience and Physiology, Department of Physiology, Metabolic Research Unit, Sahlgrenska Academy, University of Gothenburg, Box 430, S-405 30 Gothenburg, Sweden
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Quan Zhang
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK
- CNC - Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
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Shin MK, Tang WY, Amorim MR, Sham JSK, Polotsky VY. Carotid body denervation improves hyperglycemia in obese mice. J Appl Physiol (1985) 2024; 136:233-243. [PMID: 38126089 PMCID: PMC11219014 DOI: 10.1152/japplphysiol.00215.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 11/14/2023] [Accepted: 12/13/2023] [Indexed: 12/23/2023] Open
Abstract
The carotid bodies (CBs) have been implicated in glucose abnormalities in obesity via elevation of activity of the sympathetic nervous system. Obesity-induced hypertension is mediated by insulin receptor (INSR) signaling and by leptin, which binds to the leptin receptor (LEPRb) in CB and activates transient receptor potential channel subfamily M member 7 (TRPM7). We hypothesize that in mice with diet-induced obesity, hyperglycemia, glucose intolerance, and insulin resistance will be attenuated by the CB denervation (carotid sinus nerve dissection, CSND) and by knockdown of Leprb, Trpm7, and Insr gene expression in CB. In series of experiments in 75 male diet-induced obese (DIO) mice, we performed either CSND (vs. sham) surgeries or shRNA-induced suppression of Leprb, Trpm7, or Insr gene expression in CB, followed by blood pressure telemetry, intraperitoneal glucose tolerance and insulin tolerance tests, and measurements of fasting plasma insulin, leptin, corticosterone, glucagon and free fatty acids (FFAs) levels, hepatic expression of gluconeogenesis enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G-6-Pase) mRNA and liver glycogen levels. CSND decreased blood pressure, fasting blood glucose levels and improved glucose tolerance without any effect on insulin resistance. CSND did not affect any hormone levels and gluconeogenesis enzymes, but increased liver glycogen level. Genetic knockdown of CB Leprb, Trpm7, and Insr had no effect on glucose metabolism. We conclude that CB contributes to hyperglycemia of obesity, probably by modulation of the glycogen-glucose equilibrium. Diabetogenic effects of obesity on CB in mice do not occur via activation of CB Leprb, Trpm7, and Insr.NEW & NOTEWORTHY This paper provides first evidence that carotid body denervation abolishes hypertension and improves fasting blood glucose levels and glucose tolerance in mice with diet-induced obesity. Furthermore, we have shown that this phenomenon is associated with increased liver glycogen content, whereas insulin sensitivity and enzymes of gluconeogenesis were not affected.
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Affiliation(s)
- Mi-Kyung Shin
- Department of Anesthesiology and Critical Care Medicine, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
| | - Wan-Yee Tang
- Department of Environmental and Occupational Health, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania, United States
| | - Mateus R Amorim
- Department of Anesthesiology and Critical Care Medicine, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
| | - James S-K Sham
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Vsevolod Y Polotsky
- Department of Anesthesiology and Critical Care Medicine, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
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Xiao Y, Wang Y, Ryu J, Liu W, Zou H, Zhang R, Yan Y, Dai Z, Zhang D, Sun LZ, Liu F, Zhou Z, Dong LQ. Upregulated TGF-β1 contributes to hyperglycaemia in type 2 diabetes by potentiating glucagon signalling. Diabetologia 2023; 66:1142-1155. [PMID: 36917279 DOI: 10.1007/s00125-023-05889-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 01/12/2023] [Indexed: 03/16/2023]
Abstract
AIMS/HYPOTHESIS Glucagon-stimulated hepatic gluconeogenesis contributes to endogenous glucose production during fasting. Recent studies suggest that TGF-β is able to promote hepatic gluconeogenesis in mice. However, the physiological relevance of serum TGF-β levels to human glucose metabolism and the mechanism by which TGF-β enhances gluconeogenesis remain largely unknown. As enhanced gluconeogenesis is a signature feature of type 2 diabetes, elucidating the molecular mechanisms underlying TGF-β-promoted hepatic gluconeogenesis would allow us to better understand the process of normal glucose production and the pathophysiology of this process in type 2 diabetes. This study aimed to investigate the contribution of upregulated TGF-β1 in human type 2 diabetes and the molecular mechanism underlying the action of TGF-β1 in glucose metabolism. METHODS Serum levels of TGF-β1 were measured by ELISA in 74 control participants with normal glucose tolerance and 75 participants with type 2 diabetes. Human liver tissue was collected from participants without obesity and with or without type 2 diabetes for the measurement of TGF-β1 and glucagon signalling. To investigate the role of Smad3, a key signalling molecule downstream of the TGF-β1 receptor, in mediating the effect of TGF-β1 on glucagon signalling, we generated Smad3 knockout mice. Glucose levels in Smad3 knockout mice were measured during prolonged fasting and a glucagon tolerance test. Mouse primary hepatocytes were isolated from Smad3 knockout and wild-type (WT) mice to investigate the underlying molecular mechanisms. Smad3 phosphorylation was detected by western blotting, levels of cAMP were detected by ELISA and levels of protein kinase A (PKA)/cAMP response element-binding protein (CREB) phosphorylation were detected by western blotting. The dissociation of PKA subunits was measured by immunoprecipitation. RESULTS We observed higher levels of serum TGF-β1 in participants without obesity and with type 2 diabetes than in healthy control participants, which was positively correlated with HbA1c and fasting blood glucose levels. In addition, hyperactivation of the CREB and Smad3 signalling pathways was observed in the liver of participants with type 2 diabetes. Treating WT mouse primary hepatocytes with TGF-β1 greatly potentiated glucagon-stimulated PKA/CREB phosphorylation and hepatic gluconeogenesis. Mechanistically, TGF-β1 treatment induced the binding of Smad3 to the regulatory subunit of PKA (PKA-R), which prevented the association of PKA-R with the catalytic subunit of PKA (PKA-C) and led to the potentiation of glucagon-stimulated PKA signalling and gluconeogenesis. CONCLUSIONS/INTERPRETATION The hepatic TGF-β1/Smad3 pathway sensitises the effect of glucagon/PKA signalling on gluconeogenesis and synergistically promotes hepatic glucose production. Reducing serum levels of TGF-β1 and/or preventing hyperactivation of TGF-β1 signalling could be a novel approach for alleviating hyperglycaemia in type 2 diabetes.
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Affiliation(s)
- Yang Xiao
- National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
- Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Yanfei Wang
- National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
- Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
- Department of Endocrinology, The First People's Hospital of Foshan, Foshan, China
| | - Jiyoon Ryu
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Wei Liu
- National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
- Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
- Division of Biliopancreatic Surgery and Bariatric Surgery, Department of General Surgery, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Hailan Zou
- National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
- Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Rong Zhang
- National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
- Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Yin Yan
- National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
- Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Zhe Dai
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Deling Zhang
- Department of Pathophysiology, Wuhan University School of Basic Medical Sciences, Wuhan, China
| | - Lu-Zhe Sun
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Feng Liu
- National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
- Metabolic Syndrome Research Center, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Zhiguang Zhou
- National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
- Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Lily Q Dong
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA.
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Kang Q, Zheng J, Jia J, Xu Y, Bai X, Chen X, Zhang XK, Wong FS, Zhang C, Li M. Disruption of the glucagon receptor increases glucagon expression beyond α-cell hyperplasia in zebrafish. J Biol Chem 2022; 298:102665. [PMID: 36334626 PMCID: PMC9719020 DOI: 10.1016/j.jbc.2022.102665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/11/2022] Open
Abstract
The glucagon receptor (GCGR) is a potential target for diabetes therapy. Several emerging GCGR antagonism-based therapies are under preclinical and clinical development. However, GCGR antagonism, as well as genetically engineered GCGR deficiency in animal models, are accompanied by α-cell hyperplasia and hyperglucagonemia, which may limit the application of GCGR antagonism. To better understand the physiological changes in α cells following GCGR disruption, we performed single cell sequencing of α cells isolated from control and gcgr-/- (glucagon receptor deficient) zebrafish. Interestingly, beyond the α-cell hyperplasia, we also found that the expression of gcga, gcgb, pnoca, and several glucagon-regulatory transcription factors were dramatically increased in one cluster of gcgr-/- α cells. We further confirmed that glucagon mRNA was upregulated in gcgr-/- animals by in situ hybridization and that glucagon promoter activity was increased in gcgr-/-;Tg(gcga:GFP) reporter zebrafish. We also demonstrated that gcgr-/- α cells had increased glucagon protein levels and increased granules after GCGR disruption. Intriguingly, the increased mRNA and protein levels could be suppressed by treatment with high-level glucose or knockdown of the pnoca gene. In conclusion, these data demonstrated that GCGR deficiency not only induced α-cell hyperplasia but also increased glucagon expression in α cells, findings which provide more information about physiological changes in α-cells when the GCGR is disrupted.
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Affiliation(s)
- Qi Kang
- School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, China
| | - Jihong Zheng
- Fundamental Research Center, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jianxin Jia
- School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, China
| | - Ying Xu
- Fundamental Research Center, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xuanxuan Bai
- School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen, China; Fundamental Research Center, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xinhua Chen
- Key Laboratory of Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiao-Kun Zhang
- School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, China
| | - F Susan Wong
- Division of Infection and Immunity, Cardiff University School of Medicine, Cardiff, UK
| | - Chao Zhang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Mingyu Li
- School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, China.
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5
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Competing paradigms of obesity pathogenesis: energy balance versus carbohydrate-insulin models. Eur J Clin Nutr 2022; 76:1209-1221. [PMID: 35896818 PMCID: PMC9436778 DOI: 10.1038/s41430-022-01179-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/24/2022] [Accepted: 06/28/2022] [Indexed: 02/07/2023]
Abstract
The obesity pandemic continues unabated despite a persistent public health campaign to decrease energy intake (“eat less”) and increase energy expenditure (“move more”). One explanation for this failure is that the current approach, based on the notion of energy balance, has not been adequately embraced by the public. Another possibility is that this approach rests on an erroneous paradigm. A new formulation of the energy balance model (EBM), like prior versions, considers overeating (energy intake > expenditure) the primary cause of obesity, incorporating an emphasis on “complex endocrine, metabolic, and nervous system signals” that control food intake below conscious level. This model attributes rising obesity prevalence to inexpensive, convenient, energy-dense, “ultra-processed” foods high in fat and sugar. An alternative view, the carbohydrate-insulin model (CIM), proposes that hormonal responses to highly processed carbohydrates shift energy partitioning toward deposition in adipose tissue, leaving fewer calories available for the body’s metabolic needs. Thus, increasing adiposity causes overeating to compensate for the sequestered calories. Here, we highlight robust contrasts in how the EBM and CIM view obesity pathophysiology and consider deficiencies in the EBM that impede paradigm testing and refinement. Rectifying these deficiencies should assume priority, as a constructive paradigm clash is needed to resolve long-standing scientific controversies and inform the design of new models to guide prevention and treatment. Nevertheless, public health action need not await resolution of this debate, as both models target processed carbohydrates as major drivers of obesity.
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Ludwig DS, Aronne LJ, Astrup A, de Cabo R, Cantley LC, Friedman MI, Heymsfield SB, Johnson JD, King JC, Krauss RM, Lieberman DE, Taubes G, Volek JS, Westman EC, Willett WC, Yancy WS, Ebbeling CB. The carbohydrate-insulin model: a physiological perspective on the obesity pandemic. Am J Clin Nutr 2021; 114:1873-1885. [PMID: 34515299 PMCID: PMC8634575 DOI: 10.1093/ajcn/nqab270] [Citation(s) in RCA: 122] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 07/26/2021] [Indexed: 12/29/2022] Open
Abstract
According to a commonly held view, the obesity pandemic is caused by overconsumption of modern, highly palatable, energy-dense processed foods, exacerbated by a sedentary lifestyle. However, obesity rates remain at historic highs, despite a persistent focus on eating less and moving more, as guided by the energy balance model (EBM). This public health failure may arise from a fundamental limitation of the EBM itself. Conceptualizing obesity as a disorder of energy balance restates a principle of physics without considering the biological mechanisms that promote weight gain. An alternative paradigm, the carbohydrate-insulin model (CIM), proposes a reversal of causal direction. According to the CIM, increasing fat deposition in the body-resulting from the hormonal responses to a high-glycemic-load diet-drives positive energy balance. The CIM provides a conceptual framework with testable hypotheses for how various modifiable factors influence energy balance and fat storage. Rigorous research is needed to compare the validity of these 2 models, which have substantially different implications for obesity management, and to generate new models that best encompass the evidence.
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Affiliation(s)
- David S Ludwig
- New Balance Foundation Obesity Prevention Center, Boston Children's Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
- Department of Nutrition, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Louis J Aronne
- Comprehensive Weight Control Center, Weill Cornell Medicine, New York, NY, USA
| | - Arne Astrup
- Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging, NIH, Baltimore, MD, USA
| | - Lewis C Cantley
- Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Mark I Friedman
- Monell Chemical Senses Center, Philadelphia, PA, USA
- Nutrition Science Initiative, San Diego, CA, USA
| | - Steven B Heymsfield
- Metabolism & Body Composition Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - James D Johnson
- Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Institute for Personalized Therapeutic Nutrition, Vancouver, British Columbia, Canada
| | - Janet C King
- Department of Nutritional Sciences & Toxicology, University of California Berkeley, Berkeley, CA, USA
| | - Ronald M Krauss
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Daniel E Lieberman
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Gary Taubes
- Nutrition Science Initiative, San Diego, CA, USA
| | - Jeff S Volek
- Department of Human Sciences, Ohio State University, Columbus, OH, USA
| | - Eric C Westman
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Walter C Willett
- Department of Nutrition, Harvard TH Chan School of Public Health, Boston, MA, USA
- Channing Division of Network Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - William S Yancy
- Department of Medicine, Duke University School of Medicine, Durham, NC, USA
| | - Cara B Ebbeling
- New Balance Foundation Obesity Prevention Center, Boston Children's Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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7
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Zhu X, Lin C, Li L, Hu S, Cai X, Ji L. SGLT2i increased the plasma fasting glucagon level in patients with diabetes: A meta-analysis. Eur J Pharmacol 2021; 903:174145. [PMID: 33957085 DOI: 10.1016/j.ejphar.2021.174145] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 04/11/2021] [Accepted: 04/28/2021] [Indexed: 02/06/2023]
Abstract
Increased glucagon level was hypothesized to participate in the ketoacidosis associated with sodium-glucose co-transporter 2 inhibitors (SGLT2i) treatment. However, the effect of SGLT2i on glucagon remains controversial. Hence, we conducted this meta-analysis to assess the overall effect of SGLT2i treatment on plasma fasting glucagon level in patients with diabetes. PubMed/MEDLINE, Embase, and Cochrane databases were searched for studies published before August 2020. Clinical trials in patients with type 1 diabetes mellitus and type 2 diabetes mellitus with reports of glucagon changes before and after SGLT2i intervention were included. Eligible trials were analyzed by fixed-effect model, random effect model, and meta-regression analysis accordingly. In total, ten trials were included in this meta-analysis. Compared with the non-SGLT2i treatment group, SGLT2i treatment resulted in increased plasma fasting glucagon levels with significance (WMD, 8.35 pg/ml; 95% CI, 2.17-14.54 pg/ml, P<0.01) in patients with diabetes mellitus. Besides, when compared with non-SGLT2i control group, the insulin level decreased (WMD, -2.78 μU/ml; 95% CI, -5.11 to -0.46 μU/ml, P = 0.02) and ketone body level increased (WMD, 0.17 mmol/l; 95% CI, 0.09-0.25 mmol/l, P<0.01) in patients with type 2 diabetes. In conclusion, our result indicated SGLT2i intervention would increase the plasma fasting glucagon level in patients with diabetes mellitus. The increase in plasma fasting glucagon level may be associated with reduced insulin level. The increased glucagon-insulin ratio after the use of SGLT2i may make diabetic patients susceptible to ketosis.
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Affiliation(s)
- Xingyun Zhu
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Beijing, China.
| | - Chu Lin
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Beijing, China.
| | - Li Li
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Beijing, China.
| | - Suiyuan Hu
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Beijing, China.
| | - Xiaoling Cai
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Beijing, China.
| | - Linong Ji
- Department of Endocrinology and Metabolism, Peking University People's Hospital, Beijing, China.
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8
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Liao W, Yang W, Shen Z, Ai W, Pan Q, Sun Y, Guo S. Heme Oxygenase-1 Regulates Ferrous Iron and Foxo1 in Control of Hepatic Gluconeogenesis. Diabetes 2021; 70:696-709. [PMID: 33408127 PMCID: PMC7897351 DOI: 10.2337/db20-0954] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/15/2020] [Indexed: 12/23/2022]
Abstract
The liver is a key player for maintaining glucose homeostasis. Excessive hepatic glucose production is considered to be a key for the onset of type 2 diabetes. The primary function of heme oxygenase-1 (HO1) is to catalyze the degradation of heme into biliverdin, ferrous iron, and carbon monoxide. Previous studies have demonstrated that the degradation of heme by HO1 in the liver results in mitochondrial dysfunction and drives insulin resistance. In this study, by overexpressing HO1 in hepatocytes and mice, we showed that HO1 promotes gluconeogenesis in a Foxo1-dependent manner. Importantly, HO1 overexpression increased the generation of ferrous iron in the liver, which further activates nuclear factor-κB and phosphorylates Foxo1 at Ser273 to enhance gluconeogenesis. We further assessed the role of HO1 in insulin-resistant liver-specific knockout of IRS1 and IRS2 genes (L-DKO) mice, which exhibit upregulation of HO1 in the liver and hepatic ferrous iron overload. HO1 knockdown by shRNA or treatment of iron chelator rescued the aberrant gluconeogenesis in L-DKO mice. In addition, we found that systemic iron overload promotes gluconeogenesis by activating the hepatic protein kinase A→Foxo1 axis. Thus, our results demonstrate the role of HO1 in regulating hepatic iron status and Foxo1 to control gluconeogenesis and blood glucose.
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Affiliation(s)
- Wang Liao
- Department of Nutrition, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Wanbao Yang
- Department of Nutrition, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Zheng Shen
- Department of Nutrition, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Weiqi Ai
- Department of Nutrition, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Quan Pan
- Department of Nutrition, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Yuxiang Sun
- Department of Nutrition, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Shaodong Guo
- Department of Nutrition, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
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9
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Guo K, Tian Q, Yang L, Zhou Z. The Role of Glucagon in Glycemic Variability in Type 1 Diabetes: A Narrative Review. Diabetes Metab Syndr Obes 2021; 14:4865-4873. [PMID: 34992395 PMCID: PMC8710064 DOI: 10.2147/dmso.s343514] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 12/01/2021] [Indexed: 01/20/2023] Open
Abstract
Type 1 diabetes mellitus (T1DM) is a progressive disease as a result of the severe destruction of islet β-cell function, which leads to high glucose variability in patients. However, α-cell function is also compromised in patients with T1DM, characterized by aberrant fasting and postprandial glucagon secretion. According to recent studies, this aberrant glucagon secretion plays an increasing role in hyperglycemia, insulin-induced hypoglycemia and exercise-associated hypoglycemia in patients with T1DM. With application of continuous glucose monitoring system, dozens of metrics enable the assessment of glycemic variability, which is an integral component of glycemic control for patients with T1DM. There is growing evidences to illustrate the contribution of glucagon secretion to the glycemic variability in patients with T1DM, which may promote the development of new treatment strategies aiming to mitigate glycemic variability associated with aberrant glucagon secretion.
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Affiliation(s)
- Keyu Guo
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, People’s Republic of China
| | - Qi Tian
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, People’s Republic of China
| | - Lin Yang
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, People’s Republic of China
- Correspondence: Lin Yang; Zhiguang Zhou Email ;
| | - Zhiguang Zhou
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, People’s Republic of China
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11
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Saponaro C, Gmyr V, Thévenet J, Moerman E, Delalleau N, Pasquetti G, Coddeville A, Quenon A, Daoudi M, Hubert T, Vantyghem MC, Bousquet C, Martineau Y, Kerr-Conte J, Staels B, Pattou F, Bonner C. The GLP1R Agonist Liraglutide Reduces Hyperglucagonemia Induced by the SGLT2 Inhibitor Dapagliflozin via Somatostatin Release. Cell Rep 2020; 28:1447-1454.e4. [PMID: 31390560 DOI: 10.1016/j.celrep.2019.07.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 08/02/2018] [Accepted: 07/01/2019] [Indexed: 12/20/2022] Open
Abstract
The newest classes of anti-diabetic agents include sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide 1 receptor (GLP1R) agonists. The SGLT2 inhibitor dapagliflozin reduces glucotoxicity by glycosuria but elevates glucagon secretion. The GLP1R agonist liraglutide inhibits glucagon; therefore, we hypothesize that the cotreatment of dapagliflozin with liraglutide could reduce hyperglucagonemia and hyperglycemia. Here we use five complementary models: human islet cultures, healthy mice, db/db mice, diet-induced obese (DIO) mice, and somatostatin receptor-2 (SSTR2) KO mice. A single administration of liraglutide and dapagliflozin in combination improves glycemia and reduces dapagliflozin-induced glucagon secretion in diabetic mice. Chronic treatment with liraglutide and dapagliflozin produces a sustainable reduction of glycemia compared with each drug alone. Moreover, liraglutide reduces dapagliflozin-induced glucagon secretion by enhancing somatostatin release, as demonstrated by SSTR2 inhibition in human islets and in mice. Collectively, these data provide mechanistic insights into how intra-islet GLP1R activation is critical for the regulation of glucose homeostasis.
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Affiliation(s)
- Chiara Saponaro
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Valéry Gmyr
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Julien Thévenet
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Ericka Moerman
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Nathalie Delalleau
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Gianni Pasquetti
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Anais Coddeville
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Audrey Quenon
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Mehdi Daoudi
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Thomas Hubert
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Marie-Christine Vantyghem
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France; CHU Lille, Clinique Médicale: Endocrinologie Diabétologie Métabolismes, 59000 Lille, France
| | - Corinne Bousquet
- Cancer Research Center of Toulouse (CRCT), INSERM U1037, University Toulouse III Paul Sabatier, Toulouse, France; Equipe Labellisée Ligue Contre le Cancer, Toulouse, France
| | - Yvan Martineau
- Cancer Research Center of Toulouse (CRCT), INSERM U1037, University Toulouse III Paul Sabatier, Toulouse, France; Equipe Labellisée Ligue Contre le Cancer, Toulouse, France
| | - Julie Kerr-Conte
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France
| | - Bart Staels
- University of Lille, U1011-EGID, 59000 Lille, France; INSERM, U1011, 59000 Lille, France; CHU Lille, Service Biochimie Automatisée Pathologies des Protéines, 59000 Lille, France; Institut Pasteur de Lille, 59000 Lille, France
| | - François Pattou
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France; CHU Lille, Service de Chirurgie Métabolique et Endocrienne, 59000 Lille, France
| | - Caroline Bonner
- University of Lille, U1190-EGID, 59000 Lille, France; INSERM, U1190, 59000 Lille, France; Institut Pasteur de Lille, 59000 Lille, France.
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12
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Samms RJ, Coghlan MP, Sloop KW. How May GIP Enhance the Therapeutic Efficacy of GLP-1? Trends Endocrinol Metab 2020; 31:410-421. [PMID: 32396843 DOI: 10.1016/j.tem.2020.02.006] [Citation(s) in RCA: 184] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/30/2020] [Accepted: 02/06/2020] [Indexed: 12/25/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) receptor agonists improve glucose homeostasis, reduce bodyweight, and over time benefit cardiovascular health in type 2 diabetes mellitus (T2DM). However, dose-related gastrointestinal effects limit efficacy, and therefore agents possessing GLP-1 pharmacology that can also target alternative pathways may expand the therapeutic index. One approach is to engineer GLP-1 activity into the sequence of glucose-dependent insulinotropic polypeptide (GIP). Although the therapeutic implications of the lipogenic actions of GIP are debated, its ability to improve lipid and glucose metabolism is especially evident when paired with the anorexigenic mechanism of GLP-1. We review the complexity of GIP in regulating adipose tissue function and energy balance in the context of recent findings in T2DM showing that dual GIP/GLP-1 receptor agonist therapy produces profound weight loss, glycemic control, and lipid lowering.
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Affiliation(s)
- Ricardo J Samms
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Matthew P Coghlan
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Kyle W Sloop
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA.
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13
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Coco D, Leanza S, Guerra F. Total Pancreatectomy: Indications, Advantages and Disadvantages - A Review. MÆDICA 2020; 14:391-396. [PMID: 32153671 DOI: 10.26574/maedica.2019.14.4.391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background: Total pancreatectomy is an obligatory surgical procedure in locally advanced or centrally located pancreatic neoplasms to achieve complete tumour clearance. Owing to sound understanding of tumour biology and evolution in intervention technique and improved postoperative care, nowadays the indications of total pancreatectomy have taken a significant change. Aim: To review the indications of total pancreatectomy and its advantages and disadvantages under current perspectives. Method: Major databases, including PubMed, EMBASE, Science Citation Index Expanded, Scopus and the Cochrane Library, were searched for studies of total pancreatectomy and the results reported by various authors were summarized. Results: The indications of total pancreatectomy in subjects diagnosed with chronic pancreatitis were classified into four subgroups, including "Tumour", "Trouble", "Technical difficulties" and "Therapy-refractory pain". Today, total pancreatectomy has more specific and different indications than before. Currently, IPMN (intraductal papillary mucinous neoplasm) seems to have the most essential indication quantitatively. Morbidity and mortality related to total pancreatectomy are more profoundly decreased than before due to improvements in the operative techniques and post-operative managements. Some of the metabolic disorders are reported as major disadvantages of total pancreatectomy. Conclusion: Despite the disadvantages of total pancreatectomy, it remains an inevitable procedure for subjects with chronic pancreatitis, improvements in operative techniques and postoperative management ensuring long-term survival, a better quality of life, and diminished mortality and morbidity rates.
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Affiliation(s)
- Danilo Coco
- Department of General Surgery, Ospedali Riuniti Marche Nord, Pesaro, Italy
| | - Silvana Leanza
- Department of General Surgery Carlo Urbani Hospital, Jesi, Italy
| | - Francesco Guerra
- Department of General Surgery, Ospedali Riuniti Marche Nord, Pesaro, Italy
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14
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Liu X, Wang G. The Effect of High-Intensity Interval Training on Physical Parameters, Metabolomic Indexes and Serum Ficolin-3 Levels in Patients with Prediabetes and Type 2 Diabetes. Exp Clin Endocrinol Diabetes 2020; 129:740-749. [PMID: 31931532 DOI: 10.1055/a-1027-6511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Exercise benefits people with abnormal glucose metabolism, and serum ficolin-3 levels have been reported to be associated with diabetes. However, no relevant study has discussed the relationship between high-intensity interval training (HIIT) and ficolin-3 in a Chinese population. OBJECTIVE To compare the effect of HIIT and moderate-intensity continuous training (MICT) on blood pressure, glucose control, the lipid profile and the serum ficolin-3 level in patients with prediabetes and type 2 diabetes (T2D). METHODS We recruited 145 patients with prediabetes and 196 T2D patients from March to June 2018. All participants were randomly grouped into HIIT and MICT groups. HIIT consisted of progressing to twelve 1-min bouts at 90% maximal aerobic capacity (1 min recovery), and MICT consisted of progressing to 20 min at 65% maximal aerobic capacity. ˙VO2peak, body composition, blood pressure, glucose, the lipid profile and the serum ficolin-3 level were measured before and after three weeks of training. RESULTS After 3 weeks of training, participants in both the HIIT and MICT groups had significantly lower SBP, BMI, waist circumference, % body fat, and serum levels of FPG, TC, TGs, UA and ficolin-3, as well as increased vital capacity and VOmax. Additionally, the patients in the HIIT group still had significantly lower levels of 2hPG and LDL-C, regardless of prediabetes or diabetes status. After comparing the differences in the variation in parameters between the HIIT and MICT groups, we found that HIIT could help patients with prediabetes or diabetes acquire better effects of treatment in regard to anthropometry, blood pressure, glucose control, UA and ficolin-3 levels than MICT. Finally, the patients in the HIIT group had a lower rate of loss to follow-up and a higher rate of session attendance. CONCLUSIONS Both HIIT and MICT were beneficial exercise strategies for health in patients with prediabetes or T2D. However, HIIT is a more time-efficient strategy and could lower the serum level of ficolin-3 in patients after 3 weeks of training.
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Affiliation(s)
- Xiaochen Liu
- Department of Physical Education, Henan Finance University, Zhengzhou, Henan, China
| | - Gaifeng Wang
- Encephalopathy Ward, Henan Province Hospital of TCM, Zhengzhou, Henan, China
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15
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Janah L, Kjeldsen S, Galsgaard KD, Winther-Sørensen M, Stojanovska E, Pedersen J, Knop FK, Holst JJ, Wewer Albrechtsen NJ. Glucagon Receptor Signaling and Glucagon Resistance. Int J Mol Sci 2019; 20:E3314. [PMID: 31284506 PMCID: PMC6651628 DOI: 10.3390/ijms20133314] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 06/28/2019] [Accepted: 07/03/2019] [Indexed: 02/08/2023] Open
Abstract
Hundred years after the discovery of glucagon, its biology remains enigmatic. Accurate measurement of glucagon has been essential for uncovering its pathological hypersecretion that underlies various metabolic diseases including not only diabetes and liver diseases but also cancers (glucagonomas). The suggested key role of glucagon in the development of diabetes has been termed the bihormonal hypothesis. However, studying tissue-specific knockout of the glucagon receptor has revealed that the physiological role of glucagon may extend beyond blood-glucose regulation. Decades ago, animal and human studies reported an important role of glucagon in amino acid metabolism through ureagenesis. Using modern technologies such as metabolomic profiling, knowledge about the effects of glucagon on amino acid metabolism has been expanded and the mechanisms involved further delineated. Glucagon receptor antagonists have indirectly put focus on glucagon's potential role in lipid metabolism, as individuals treated with these antagonists showed dyslipidemia and increased hepatic fat. One emerging field in glucagon biology now seems to include the concept of hepatic glucagon resistance. Here, we discuss the roles of glucagon in glucose homeostasis, amino acid metabolism, and lipid metabolism and present speculations on the molecular pathways causing and associating with postulated hepatic glucagon resistance.
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Affiliation(s)
- Lina Janah
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Sasha Kjeldsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Katrine D Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Marie Winther-Sørensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Elena Stojanovska
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Department of Cardiology, Nephrology and Endocrinology, Nordsjællands Hospital Hillerød, University of Copenhagen, 3400 Hillerød, Denmark
| | - Filip K Knop
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, 2900 Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, 2820 Gentofte, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark.
- Department of Clinical Biochemistry, Rigshospitalet, 2100 Copenhagen, Denmark.
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark.
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16
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Ojha A, Ojha U, Mohammed R, Chandrashekar A, Ojha H. Current perspective on the role of insulin and glucagon in the pathogenesis and treatment of type 2 diabetes mellitus. Clin Pharmacol 2019; 11:57-65. [PMID: 31191043 PMCID: PMC6515536 DOI: 10.2147/cpaa.s202614] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/28/2019] [Indexed: 01/17/2023] Open
Abstract
According to the World Health Organization, 422 million adults worldwide live with diabetes mellitus (DM), a significant portion of whom have type 2 diabetes. The discovery of insulin as a key regulator of glucose metabolism has revolutionized our understanding of DM and provided several therapeutic avenues. Most studies have so far predominantly focused on the role of insulin in type 2 diabetes. However, the balance between insulin and glucagon is essential in ensuring glucose homeostasis. In this review, we begin by evaluating the principal differences between insulin and glucagon with regard to their mechanism and control of their secretion. Next, we discuss their mode of action and effects on metabolism. We further explore how the two hormones impact the natural history of type 2 diabetes. Finally, we outline how current and emerging pharmacological agents attempt to exploit the properties of insulin and glucagon to benefit patients with type 2 diabetes.
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Affiliation(s)
- Ashutosh Ojha
- Shobhaben Pratapbhai Patel School Of Pharmacy & Technology Management, SVKM's Narsee Monjee Institute of Management Studies, Mumbai, India
| | - Utkarsh Ojha
- Faculty of Medicine, Imperial College London, London, UK
| | - Raihan Mohammed
- Department of Medicine, University of Cambridge, Cambridge, UK
| | | | - Harsh Ojha
- Department of Life Sciences, University of Warwick, Coventry, UK
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17
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Capozzi ME, Svendsen B, Encisco SE, Lewandowski SL, Martin MD, Lin H, Jaffe JL, Coch RW, Haldeman JM, MacDonald PE, Merrins MJ, D'Alessio DA, Campbell JE. β Cell tone is defined by proglucagon peptides through cAMP signaling. JCI Insight 2019; 4:126742. [PMID: 30720465 DOI: 10.1172/jci.insight.126742] [Citation(s) in RCA: 156] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 01/29/2019] [Indexed: 01/05/2023] Open
Abstract
Paracrine interactions between pancreatic islet cells have been proposed as a mechanism to regulate hormone secretion and glucose homeostasis. Here, we demonstrate the importance of proglucagon-derived peptides (PGDPs) for α to β cell communication and control of insulin secretion. Signaling through this system occurs through both the glucagon-like peptide receptor (Glp1r) and glucagon receptor (Gcgr). Loss of PGDPs, or blockade of their receptors, decreases insulin secretion in response to both metabolic and nonmetabolic stimulation of mouse and human islets. This effect is due to reduced β cell cAMP and affects the quantity but not dynamics of insulin release, indicating that PGDPs dictate the magnitude of insulin output in an isolated islet. In healthy mice, additional factors that stimulate cAMP can compensate for loss of PGDP signaling; however, input from α cells is essential to maintain glucose tolerance during the metabolic stress induced by high-fat feeding. These findings demonstrate an essential role for α cell regulation of β cells, raising the possibility that abnormal paracrine signaling contributes to impaired insulin secretion in diabetes. Moreover, these findings support reconsideration of the role for α cells in postprandial glucose control.
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Affiliation(s)
- Megan E Capozzi
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Berit Svendsen
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Sara E Encisco
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Sophie L Lewandowski
- Department of Medicine, Division of Endocrinology, Diabetes & Metabolism, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Mackenzie D Martin
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Haopeng Lin
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Alberta, Canada
| | - Justin L Jaffe
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Reilly W Coch
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA.,Department of Medicine and
| | - Jonathan M Haldeman
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA.,Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, USA
| | - Patrick E MacDonald
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Alberta, Canada
| | - Matthew J Merrins
- Department of Medicine, Division of Endocrinology, Diabetes & Metabolism, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - David A D'Alessio
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA.,Department of Medicine and
| | - Jonathan E Campbell
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA.,Department of Medicine and.,Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, USA
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18
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Drucker DJ. The Discovery of GLP-2 and Development of Teduglutide for Short Bowel Syndrome. ACS Pharmacol Transl Sci 2019; 2:134-142. [PMID: 32219218 DOI: 10.1021/acsptsci.9b00016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Indexed: 12/18/2022]
Abstract
The proglucagon gene encodes multiple structurally related peptides with overlapping actions promoting the absorption and assimilation of ingested energy. Notably, glucagon has been developed pharmaceutically to treat hypoglycemia, and glucagon-like peptide-1 (GLP-1) receptor agonists are used for the therapy of type 2 diabetes and obesity. Here I describe the discovery of glucagon-like peptide-2 (GLP-2), a 33 amino acid peptide cosecreted together with GLP-1 from gut endocrine cells. GLP-2 was found to exhibit robust intestinal growth-promoting activity, following serendipitous observations that proglucagon-producing tumors induced intestinal growth in mice. Key developments in the pharmaceutical development of GLP-2 included the cloning of the GLP-2 receptor, and the recognition of the importance of dipeptidyl peptidase-4 as a critical determinant of GLP-2 bioactivity. A therapeutic focus on short bowel syndrome, a serious medical disorder with compelling unmet medical need, enabled the pharmaceutical development of a simple GLP-2 analogue, teduglutide, suitable for once daily administration.
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Affiliation(s)
- Daniel J Drucker
- Department of Medicine, the Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Ontario M5G 1X5, Canada
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19
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Pre-meal and postprandial lipaemia in subjects with the metabolic syndrome: effects of timing and protein quality (randomised crossover trial). Br J Nutr 2019; 121:312-321. [PMID: 30599817 DOI: 10.1017/s0007114518003264] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Non-fasting TAG - postprandial lipaemia (PPL) - are to a higher degree associated with cardiovascular risk compared with fasting TAG. Dietary protein, especially whey proteins (WP), may lower PPL. We hypothesised that a WP pre-meal (17·6 g protein) consumed 15 v. 30 min before a fat-rich meal reduces the PPL response in subjects with the metabolic syndrome (MetS) and that a WP pre-meal has more potent effects than casein and gluten pre-meals. A total of sixteen subjects with the MetS completed an acute, randomised, crossover trial. WP pre-meals were consumed 15 and 30 min, and casein and gluten 15 min before a fat-rich meal. Blood samples were drawn 360 min postprandially to determine metabolite and hormone responses, S-paracetamol (for assessment of gastric emptying) and amino acids. Insulin and glucagon responses were affected by both timing and protein type (for all P <0·01), with significantly higher concentrations for WP given at -15 min than WP at -30 min and higher responses compared with gluten for the first 30 min after pre-meal consumption (for all P <0·05). The PPL responses changed neither by timing nor by protein type. Glucose-dependent insulinotropic peptide but not glucagon-like peptide 1 responses differed between the three protein types. S-paracetamol concentration was higher for WP (-30 min) than for WP (-15 min) 15 min after the main meal (P = 0·028), and higher for casein and gluten than for WP at time point 30 min (for all P <0·05). In conclusion, the PPL response was not changed by ingestion of a 17·6 g protein pre-meal, whereas both timing and protein quality affected hormone secretion (insulin and glucagon).
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20
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Wu Y, Pan Q, Yan H, Zhang K, Guo X, Xu Z, Yang W, Qi Y, Guo CA, Hornsby C, Zhang L, Zhou A, Li L, Chen Y, Zhang W, Sun Y, Zheng H, Wondisford F, He L, Guo S. Novel Mechanism of Foxo1 Phosphorylation in Glucagon Signaling in Control of Glucose Homeostasis. Diabetes 2018; 67:2167-2182. [PMID: 30201683 PMCID: PMC6198346 DOI: 10.2337/db18-0674] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/21/2018] [Indexed: 12/19/2022]
Abstract
Dysregulation of hepatic glucose production (HGP) serves as a major underlying mechanism for the pathogenesis of type 2 diabetes. The pancreatic hormone glucagon increases and insulin suppresses HGP, controlling blood glucose homeostasis. The forkhead transcription factor Foxo1 promotes HGP through increasing expression of genes encoding the rate-limiting enzymes responsible for gluconeogenesis. We previously established that insulin suppresses Foxo1 by Akt-mediated phosphorylation of Foxo1 at Ser256 in human hepatocytes. In this study, we found a novel Foxo1 regulatory mechanism by glucagon, which promotes Foxo1 nuclear translocation and stability via cAMP- and protein kinase A-dependent phosphorylation of Foxo1 at Ser276 Replacing Foxo1-S276 with alanine (A) or aspartate (D) to block or mimic phosphorylation, respectively, markedly regulates Foxo1 stability and nuclear localization in human hepatocytes. To establish in vivo function of Foxo1-Ser276 phosphorylation in glucose metabolism, we generated Foxo1-S273A and Foxo1-S273D knock-in (KI) mice. The KI mice displayed impaired blood glucose homeostasis, as well as the basal and glucagon-mediated HGP in hepatocytes. Thus, Foxo1-Ser276 is a new target site identified in the control of Foxo1 bioactivity and associated metabolic diseases.
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Affiliation(s)
- Yuxin Wu
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Quan Pan
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Hui Yan
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Kebin Zhang
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Xiaoqin Guo
- Department of Endocrinology, Third Military Medical University, Chongqing, China
- Division of Endocrinology, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Zihui Xu
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Wanbao Yang
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Yajuan Qi
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Cathy A Guo
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Caitlyn Hornsby
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Lin Zhang
- Department of Chemistry, Cleveland State University, Cleveland, OH
| | - Aimin Zhou
- Department of Chemistry, Cleveland State University, Cleveland, OH
| | - Ling Li
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Yunmei Chen
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Weiping Zhang
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Yuxiang Sun
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
| | - Hongting Zheng
- Department of Endocrinology, Third Military Medical University, Chongqing, China
| | - Fred Wondisford
- Division of Endocrinology, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Ling He
- Division of Endocrinology, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Shaodong Guo
- Department of Nutrition and Food Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX
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21
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Strowski MZ. Impact of FGF21 on glycemic control. Horm Mol Biol Clin Investig 2017; 30:/j/hmbci.ahead-of-print/hmbci-2017-0001/hmbci-2017-0001.xml. [PMID: 28593912 DOI: 10.1515/hmbci-2017-0001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 02/07/2017] [Indexed: 11/15/2022]
Abstract
Fibroblast growth factor 21 (FGF21) plays a role in regulating adaptation to various metabolic abnormalities. In addition, FGF21 is involved in controlling glucose and lipid homeostasis. The regulation of FGF21 is a complex process and depends upon multiple metabolic factors and hormones. Humans and animals with obesity or type 2 diabetes have abnormal expression and changes of FGF21 in the circulation. Interventional studies in rodents and monkeys with obesity, insulin resistance or type 2 diabetes revealed a potential therapeutic relevance of FGF21 in correcting these abnormalities. This review summarizes the current knowledge about the regulation of FGF21 by distinct metabolic and endogenous factors, considering the most relevant studies. In this context, the results of interventional studies in humans and various animal models of diseases, such as diabetes and obesity, are discussed. In addition, potential mechanisms of the molecular regulation of FGF21 expression and secretion are reviewed.
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Yu J, Zhang Y, Sun W, Kahkoska AR, Wang J, Buse JB, Gu Z. Insulin-Responsive Glucagon Delivery for Prevention of Hypoglycemia. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:10.1002/smll.201603028. [PMID: 28318091 PMCID: PMC5769873 DOI: 10.1002/smll.201603028] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 01/01/2017] [Indexed: 05/17/2023]
Abstract
Hypoglycemia, the state of abnormally low blood glucose level, is an acute complication of insulin and sulfonylurea therapy in diabetes management. Frequent insulin dosing and boluses during daily diabetes care leads to an increased risk of dangerously low glucose levels, which can cause behavioral and cognitive disturbance, seizure, coma, and even death. This study reports an insulin-responsive glucagon delivery method based on a microneedle (MN)-array patch for the prevention of hypoglycemia. The controlled release of glucagon is achieved in response to elevated insulin concentration by taking advantage of the specific interaction between insulin aptamer and target insulin. Integrating a painless MN-array patch, it is demonstrated that this insulin-triggered glucagon delivery device is able to prevent hypoglycemia following a high-dose insulin injection in a chemically induced type 1 diabetic mouse model.
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Affiliation(s)
- Jicheng Yu
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, 27695, USA
- Center for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Yuqi Zhang
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, 27695, USA
- Center for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Wujin Sun
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, 27695, USA
- Center for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Anna R Kahkoska
- Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Jinqiang Wang
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, 27695, USA
- Center for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - John B Buse
- Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Zhen Gu
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, 27695, USA
- Center for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
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23
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Ranjan A, Schmidt S, Damm-Frydenberg C, Steineck I, Clausen TR, Holst JJ, Madsbad S, Nørgaard K. Low-Carbohydrate Diet Impairs the Effect of Glucagon in the Treatment of Insulin-Induced Mild Hypoglycemia: A Randomized Crossover Study. Diabetes Care 2017; 40:132-135. [PMID: 27797928 DOI: 10.2337/dc16-1472] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 10/01/2016] [Indexed: 02/03/2023]
Abstract
OBJECTIVE This study compared the ability of glucagon to restore plasma glucose (PG) after mild hypoglycemia in patients with type 1 diabetes on an isocaloric high-carbohydrate diet (HCD) versus a low-carbohydrate diet (LCD). RESEARCH DESIGN AND METHODS Ten patients with insulin pump-treated type 1 diabetes randomly completed 1 week of the HCD (≥250 g/day) and 1 week of the LCD (≤50 g/day). After each week, mild hypoglycemia was induced by a subcutaneous insulin bolus in the fasting state. When PG reached 3.9 mmol/L, 100 µg glucagon was given subcutaneously, followed by 500 µg glucagon 2 h later. RESULTS Compared with the HCD, the LCD resulted in lower incremental rises in PG after the first (mean ± SEM: 1.3 ± 0.3 vs. 2.7 ± 0.4 mmol/L, P = 0.002) and second glucagon bolus (4.1 ± 0.2 vs. 5.6 ± 0.5 mmol/L, P = 0.002). No differences were observed between the diets regarding concentrations of insulin, glucagon, and triglycerides. CONCLUSIONS The LCD reduces the treatment effect of glucagon on mild hypoglycemia. Carbohydrate intake should be considered when low-dose glucagon is used to correct hypoglycemia.
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Affiliation(s)
- Ajenthen Ranjan
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark .,Danish Diabetes Academy, Odense, Denmark
| | - Signe Schmidt
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.,Danish Diabetes Academy, Odense, Denmark
| | | | - Isabelle Steineck
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.,Danish Diabetes Academy, Odense, Denmark
| | | | - Jens Juul Holst
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sten Madsbad
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kirsten Nørgaard
- Department of Endocrinology, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
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24
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Taleb N, Haidar A, Messier V, Gingras V, Legault L, Rabasa-Lhoret R. Glucagon in artificial pancreas systems: Potential benefits and safety profile of future chronic use. Diabetes Obes Metab 2017; 19:13-23. [PMID: 27629286 DOI: 10.1111/dom.12789] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 09/09/2016] [Accepted: 09/11/2016] [Indexed: 12/17/2022]
Abstract
The role of glucagon in the pathophysiology of diabetes has long been recognized, although its approved clinical use has so far been limited to the emergency treatment of severe hypoglycaemia. A novel use of glucagon as intermittent mini-boluses is proposed in the dual-hormone version (insulin and glucagon) of the external artificial pancreas. Short-term studies suggest that the incorporation of glucagon into artificial pancreas systems has the potential to further decrease hypoglycaemic risk and improve overall glucose control; however, the potential long-term safety and benefits also need to be investigated given the recognized systemic effects of glucagon. In the present report, we review the available animal and human data on the physiological functions of glucagon, as well as its pharmacological use, according to dosing and duration (acute and chronic). Along with its main role in hepatic glucose metabolism, glucagon affects the cardiovascular, renal, pulmonary and gastrointestinal systems. It has a potential role in weight reduction through its central satiety function and its role in increasing energy expenditure. Most of the pharmacological studies investigating the effects of glucagon have used doses exceeding 1 mg, in contrast to the mini-boluses used in the artificial pancreas. The available data are reassuring but comprehensive human studies using small but chronic glucagon doses that are close to the physiological ranges are lacking. We propose a list of variables that could be monitored during long-term trials of the artificial pancreas. Such trials should address the questions about the risk-benefit ratio of chronic glucagon use.
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Affiliation(s)
- Nadine Taleb
- Metabolic diseases unit, Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
- Department of Biomedical Sciences, Faculty of Medicine, Édouard-Montpetit, Université de Montréal, Montréal, Québec, Canada
| | - Ahmad Haidar
- Department of Biomedical Engineering, Faculty of Medicine, McGill University, Montréal, Québec, Canada
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, McGill University, Montréal, Québec, Canada
| | - Virginie Messier
- Metabolic diseases unit, Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
| | - Véronique Gingras
- Metabolic diseases unit, Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
- Nutrition Department, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Laurent Legault
- Montreal Children's Hospital, Department of Pediatrics, McGill University Health Centre, Montréal, Québec, Canada
| | - Rémi Rabasa-Lhoret
- Metabolic diseases unit, Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
- Montreal Diabetes Research Center, Montréal, Québec, Canada
- Nutrition Department, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
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25
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Kruger DF, Aronoff SL, Edelman SV. Through the Looking Glass. DIABETES EDUCATOR 2016; 33 Suppl 2:32S-46S; quiz 47S-48S. [PMID: 17483531 DOI: 10.1177/0145721707299766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Davida F Kruger
- The Division of Endocrinology and Metabolism, Henry Ford Health System, Detroit, Michigan (Ms Kruger)
| | - Stephen L Aronoff
- The Research Institute of Dallas, University of Texas Southwestern Medical School at Dallas, and Endocrine Associates of Dallas, Texas (Dr Aronoff)
| | - Steven V Edelman
- Taking Control of Your Diabetes, Del Mar, California, and the Division of Endocrinology, Diabetes and Metabolism, University of California, San Diego, School of Medicine (Dr Edelman)
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26
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Abstract
An elective total pancreatectomy (TP) was first performed by Eugene Rockey of Portland, Oregon, in 1942. In the 1960s and 1970s, TP was the routine resection for pancreatic cancer in many centers because of fear of a leaking pancreatojejunostomy and multicentricity of the disease but the result used to be dreadful (in today's perspective). However, more recently, postoperative mortality and morbidity after pancreatic resections have improved due to better anastomotic technique and pre-, peri- and postoperative care. Today, TP - despite being a more extensive operation - can be offered with about the same operation risk as that of a Whipple procedure. Also, major improvements in the control of diabetes have been seen and there is actually an ongoing discussion on the actual severity of the diabetic state after TP. Also, the development of modern pancreatic enzyme preparations with sufficient control of endocrine and exocrine pancreatic insufficiency provides options for overcoming the postoperative problems following TP. Due to the improved results, there are today different - and more specific - indications than before for TP: malignant tumors growing from the pancreatic head into the left pancreas, pancreatic head cancer where it is not possible to secure a tumor-free resection margin with extended resection or with dubious changes in the pancreatic main duct at frozen section, recurrent malignancy in the pancreatic remnant, at cancer surgery with resection of the celiac trunk, rescue pancreatectomy after a leaking pancreatojejunostomy with sepsis or bleeding after a Whipple-type first resection, multifocal intraductal papillary mucinous neoplasm with potentially malignant foci present in all parts of the gland, multiple metastases of renal cell carcinoma and melanoma without any residual tumor outside the pancreatic gland (possibly also other specified but uncommon metastatic tumors with a potential for cure by pancreatectomy), multifocal neuroendocrine tumors including multiple endocrine neoplasia and hereditary pancreatic cancer with a high grade of cancer penetration risk for the bearers.
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Affiliation(s)
- Åke Andrén-Sandberg
- Department of Digestive Diseases, Karolinska University Hospital, Stockholm, Sweden
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27
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Damond N, Thorel F, Moyers JS, Charron MJ, Vuguin PM, Powers AC, Herrera PL. Blockade of glucagon signaling prevents or reverses diabetes onset only if residual β-cells persist. eLife 2016; 5. [PMID: 27092792 PMCID: PMC4871705 DOI: 10.7554/elife.13828] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/07/2016] [Indexed: 12/15/2022] Open
Abstract
Glucagon secretion dysregulation in diabetes fosters hyperglycemia. Recent studies report that mice lacking glucagon receptor (Gcgr-/-) do not develop diabetes following streptozotocin (STZ)-mediated ablation of insulin-producing β-cells. Here, we show that diabetes prevention in STZ-treated Gcgr-/- animals requires remnant insulin action originating from spared residual β-cells: these mice indeed became hyperglycemic after insulin receptor blockade. Accordingly, Gcgr-/- mice developed hyperglycemia after induction of a more complete, diphtheria toxin (DT)-induced β-cell loss, a situation of near-absolute insulin deficiency similar to type 1 diabetes. In addition, glucagon deficiency did not impair the natural capacity of α-cells to reprogram into insulin production after extreme β-cell loss. α-to-β-cell conversion was improved in Gcgr-/- mice as a consequence of α-cell hyperplasia. Collectively, these results indicate that glucagon antagonism could i) be a useful adjuvant therapy in diabetes only when residual insulin action persists, and ii) help devising future β-cell regeneration therapies relying upon α-cell reprogramming. DOI:http://dx.doi.org/10.7554/eLife.13828.001 After meals, digested food causes sugar to accumulate in the blood. This triggers the release of the hormone insulin from beta cells in the pancreas, which allows liver cells, muscle cells and fat cells to use and store the sugar for energy. Other cells in the pancreas, called alpha cells, release a hormone called glucagon that counteracts the effects of insulin by telling the liver to release sugar into the bloodstream. The balance between the activity of insulin and glucagon keeps blood sugar levels steady. Diabetes results from the body being unable to produce enough insulin or respond to the insulin that is produced, which results in sugar accumulating in the blood. Diabetes also increases the production of glucagon, which further increases blood sugar levels. Recently, some researchers have reported that mice that lack the receptor proteins through which glucagon works do not develop diabetes, even when they are treated with a drug called streptozotocin that wipes out most of their beta cells. This suggests that the high blood sugar levels seen in diabetes result from an excess of glucagon, and not a lack of insulin. Drugs that block the action of glucagon have been found to reduce the symptoms of mild diabetes in mice and are now being tested in humans. However, it is less clear whether this treatment has any benefits in animals with more severe diabetes. Streptozotocin destroys most of a mouse’s beta cells but a significant fraction of them persist, while a different system relying on diphtheria toxin destroys more than 99% of these cells. Damond et al. have now found that treating mice that lack glucagon receptors with diphtheria toxin causes the mice to develop severe diabetes. Mice that lacked glucagon receptors that had been treated with streptozotocin also developed diabetes after they had been treated with an insulin-blocking drug. Further experiments showed that blocking glucagon receptors in typical mice with diabetes reduces blood sugar, but only if there is some insulin left in their bodies. Damond et al. also found that the glucagon receptor-lacking mice have more alpha cells, which have the ability to convert into insulin-producing cells after the widespread destruction of beta cells. Together, the experiments suggest that blocking glucagon could be a useful treatment for diabetes, but only in individuals who still have some insulin-producing cells. Such treatment would help reduce the release of sugar from the liver and increase the production of insulin in converted alpha cells in the pancreas. Damond et al. are now investigating how alpha cells convert into beta cells, with the aim of learning how to make beta cells regenerate more efficiently. DOI:http://dx.doi.org/10.7554/eLife.13828.002
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Affiliation(s)
- Nicolas Damond
- Department of Genetic Medicine and Development of the Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland.,Centre facultaire du diabète, University of Geneva, Geneva, Switzerland
| | - Fabrizio Thorel
- Department of Genetic Medicine and Development of the Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland.,Centre facultaire du diabète, University of Geneva, Geneva, Switzerland
| | - Julie S Moyers
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, United States
| | - Maureen J Charron
- Departments of Biochemistry, Medicine, and Obstetrics & Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, United States
| | - Patricia M Vuguin
- Pediatric Endocrinology, Women's and Childrens Health, College of Physicians & Surgeons, Columbia University, New York, United States
| | - Alvin C Powers
- Division of Diabetes, Endocrinology & Metabolism, Department of Medicine, Department of Molecular Physiology, Vanderbilt University, Nashville, United States.,VA Tennessee Valley Healthcare System, Nashville, United States
| | - Pedro L Herrera
- Department of Genetic Medicine and Development of the Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland.,Centre facultaire du diabète, University of Geneva, Geneva, Switzerland
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28
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Timofte D, Ionescu L, Ochiuz L. Mini-Review on the Glucose Metabolism Modifications after Pancreatic Resection. INTERNATIONAL LETTERS OF NATURAL SCIENCES 2016. [DOI: 10.56431/p-3zq2cx] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Pancreatic cancer is one of the most severe malignant disease, with an extreme degree of lethality, considering that the survival rate at 5 years is up to 4%. In addition, a major disadvantage of this disease is the fact that the diagnosis is determined very late in the evolution of the disorder, despite the development of new technologies. In this way, the main symptoms are occurring later on, when the tumour is already locally advanced and unresectable. Up to now surgery is the only modality that can provide a greater chance of survival, but unfortunately the pancreatic resection has many unknowns and controversies around it. Moreover, the studies on endocrine pancreatic function after resection are very few and somehow controversial. In this way, in the present mini-review we will describe the most relevant experimental data regarding the post-resection pancreatogenic diabetes, the pancreatic polypeptide PP and the pancreatic glucose metabolism after resection or the glucose metabolism after partial or total pancreatectomy.
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29
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Timofte D, Ionescu L, Ochiuz L. Mini-Review on the Glucose Metabolism Modifications after Pancreatic Resection. INTERNATIONAL LETTERS OF NATURAL SCIENCES 2016. [DOI: 10.18052/www.scipress.com/ilns.53.65] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Pancreatic cancer is one of the most severe malignant disease, with an extreme degree of lethality, considering that the survival rate at 5 years is up to 4%. In addition, a major disadvantage of this disease is the fact that the diagnosis is determined very late in the evolution of the disorder, despite the development of new technologies. In this way, the main symptoms are occurring later on, when the tumour is already locally advanced and unresectable. Up to now surgery is the only modality that can provide a greater chance of survival, but unfortunately the pancreatic resection has many unknowns and controversies around it. Moreover, the studies on endocrine pancreatic function after resection are very few and somehow controversial. In this way, in the present mini-review we will describe the most relevant experimental data regarding the post-resection pancreatogenic diabetes, the pancreatic polypeptide PP and the pancreatic glucose metabolism after resection or the glucose metabolism after partial or total pancreatectomy.
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30
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Abstract
OBJECTIVE There is general recognition that insulin and glucagon are the main hormones involved in the pathophysiology of diabetes, but the role of glucagon in diabetes is complex and in some circumstances controversial. The increasing appreciation of the role of glucagon in currently used hypoglycemic agents and the ongoing development of glucagon-targeted therapies underscores glucagon's important contribution in optimizing diabetes management. The current review provides a background on glucagon physiology and pathophysiology and an update for investigators, endocrinologists, and other healthcare providers on glucagon-modulating therapies. METHODS A literature review was conducted utilizing published literature in PubMed and AccessMedicine including the years 1922-2015 using the following key words: glucagon, bihormonal, diabetes mellitus, glucagon antagonists, glucagon-targeted therapies. RESULTS Glucagon is a counterregulatory hormone that promotes hepatic glucose production, thus preventing hypoglycemia in normal physiology. In patients with diabetes mellitus, glucagon secretion may be unregulated, which contributes to problems with glucose homeostasis. Several of the most effective therapies for diabetes have been found to suppress glucagon secretion or action, which may contribute to their success. Additionally, glucagon-specific targeted therapies, such as glucagon receptor antagonists, are being studied at a basic and clinical level. CONCLUSION Glucagon plays an important role in contributing to hyperglycemia in patients with diabetes. Utilizing hypoglycemic agents that decrease glucagon secretion or inhibit glucagon action can help improve glycemic control, making these agents a valuable resource in diabetes therapy.
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31
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de Herder WW, Rehfeld JF, Kidd M, Modlin IM. A short history of neuroendocrine tumours and their peptide hormones. Best Pract Res Clin Endocrinol Metab 2016; 30:3-17. [PMID: 26971840 DOI: 10.1016/j.beem.2015.10.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The discovery of neuroendocrine tumours of the gastrointestinal tract and pancreas started in 1870, when Rudolf Heidenhain discovered the neuroendocrine cells, which can lead to the development of these tumours. Siegfried Oberndorfer was the first to introduce the term carcinoid in 1907. The pancreatic islet cells were first described in 1869 by Paul Langerhans. In 1924, Seale Harris was the first to describe endogenous hyperinsulinism/insulinoma. In 1942 William Becker and colleagues were the first to describe the glucagonoma syndrome. The first description of gastrinoma by Robert Zollinger and Edwin Ellison dates from 1955. The first description of the VIPoma syndrome by John Verner and Ashton Morrison dates from 1958. In 1977, the groups of Lars-Inge Larsson and Jens Rehfeld, and of Om Ganda reported the first cases of somatostatinoma. But only in 2013, Jens Rehfeld and colleagues described the CCK-oma syndrome. The most recently updated WHO classification for gastrointestinal neuroendocrine tumours dates from 2010.
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Affiliation(s)
- Wouter W de Herder
- Department of Internal Medicine, Section of Endocrinology, Erasmus MC, Rotterdam, The Netherlands.
| | - Jens F Rehfeld
- Department of Clinical Biochemistry, The National University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Mark Kidd
- Wren Laboratories LLC, Branford, CT, USA
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32
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Abstract
The alpha cells that co-occupy the islets in association with beta cells have been long recognized as the source of glucagon, a hyperglycemia-producing and diabetogenic hormone. Although the mechanisms that control the functions of alpha cells, glucagon secretion, and the role of glucagon in diabetes have remained somewhat enigmatic over the fifty years since their discovery, seminal findings during the past few years have moved alpha cells into the spotlight of scientific discovery. These findings obtained largely from studies in mice are: Alpha cells have the capacity to trans-differentiate into insulin-producing beta cells. Alpha cells contain a GLP-1 generating system that produces GLP-1 locally for paracrine actions within the islets that likely promotes beta cell growth and survival and maintains beta cell mass. Impairment of glucagon signaling both prevents the occurrence of diabetes in conditions of the near absence of insulin and expands alpha cell mass. Alpha cells appear to serve as helper cells or guardians of beta cells to ensure their health and well-being. Of potential relevance to the possibility of promoting the transformation of alpha to beta cells is the observation that impairment of glucagon signaling leads to a marked increase in alpha cell mass in the islets. Such alpha cell hyperplasia provides an increased supply of alpha cells for their transdifferentiation into new beta cells. In this review we discuss these recent discoveries from the perspective of their potential relevance to the treatment of diabetes.
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Affiliation(s)
- Violeta Stanojevic
- Laboratory of Molecular Endocrinology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Joel F Habener
- Laboratory of Molecular Endocrinology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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33
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Triplitt C, Solis-Herrera C, Cersosimo E, Abdul-Ghani M, Defronzo RA. Empagliflozin and linagliptin combination therapy for treatment of patients with type 2 diabetes mellitus. Expert Opin Pharmacother 2015; 16:2819-33. [PMID: 26583910 DOI: 10.1517/14656566.2015.1114098] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Many patients with type 2 diabetes mellitus (T2DM) fail to achieve the desired A1c goal because the antidiabetic medications used do not correct the underlying pathophysiologic abnormalities and monotherapy is not sufficiently potent to reduce the A1c to the 6.5 - 7.0% range. Insulin resistance and islet (beta and alpha) cell dysfunction are major pathophysiologic abnormalities in T2DM. We examine combination therapy with linagliptin plus empagliflozin as a therapeutic approach for the treatment of inadequately controlled T2DM patients. AREAS COVERED A literature search of all human diabetes, metabolism and general medicine journals from year 2000 to the present was conducted. Glucagon like peptide-1 (GLP-1) deficiency/resistance contributes to islet cell dysfunction by impairing insulin secretion and increasing glucagon secretion. DPP-4 inhibitors (DPP4i) improve pancreatic islet function by augmenting glucose-dependent insulin secretion and decreasing elevated plasma glucagon levels. Linagliptin, a DPP-4 inhibitor, reduces HbA1c, is weight neutral, has an excellent safety profile and a low risk of hypoglycemia. The expression of sodium-glucose cotransporter-2 (SGLT2) in the proximal renal tubule is upregulated in T2DM, causing excess reabsorption of filtered glucose. The SGLT2 inhibitor (SGLT2i), empagliflozin, improves HbA1c by causing glucosuria and ameliorating glucotoxicity. It also decreases weight and blood pressure, and has a low risk of hypoglycemia. EXPERT OPINION The once daily oral combination of linagliptin plus empagliflozin does not increase the risk of hypoglycemia and tolerability and discontinuation rates are similar to those with each as monotherapy. At HbA1c values below 8.5% linagliptin/empagliflozin treatment produces an additive effect, whereas above 8.5%, there is a less than additive reduction with combination therapy compared with the effect of each agent alone. Linagliptin/empagliflozin addition is a logical combination in patients with T2DM, especially those with an HbA1c < 8.5%.
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Affiliation(s)
- C Triplitt
- a Department of Medicine, Diabetes Division , University of Texas Health Science Center and Texas Diabetes Institute , San Antonio , TX 78229 , USA
| | - C Solis-Herrera
- a Department of Medicine, Diabetes Division , University of Texas Health Science Center and Texas Diabetes Institute , San Antonio , TX 78229 , USA
| | - E Cersosimo
- a Department of Medicine, Diabetes Division , University of Texas Health Science Center and Texas Diabetes Institute , San Antonio , TX 78229 , USA
| | - M Abdul-Ghani
- a Department of Medicine, Diabetes Division , University of Texas Health Science Center and Texas Diabetes Institute , San Antonio , TX 78229 , USA
| | - Ralph A Defronzo
- a Department of Medicine, Diabetes Division , University of Texas Health Science Center and Texas Diabetes Institute , San Antonio , TX 78229 , USA
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Reiband HK, Schmidt S, Ranjan A, Holst JJ, Madsbad S, Nørgaard K. Dual-hormone treatment with insulin and glucagon in patients with type 1 diabetes. Diabetes Metab Res Rev 2015; 31:672-9. [PMID: 25533565 DOI: 10.1002/dmrr.2632] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 12/08/2014] [Indexed: 11/09/2022]
Abstract
Intensive insulin treatment in type 1 diabetes reduces the incidence and slows the progression of microvascular and macrovascular complications; however, it is associated with an increased risk of hypoglycaemia and weight gain. In this review, we propose dual-hormone treatment with insulin and glucagon as a method for achieving near normalization of blood glucose levels without increasing hypoglycaemia frequency and weight gain. We briefly summarize glucagon pathophysiology in type 1 diabetes as well as the current applications of glucagon for the treatment of hypoglycaemia. Until now, the use of glucagon has been limited by the need for reconstitution immediately before use, because of instability of the available compounds; however, stabile compounds are soon to be launched and will render long-term intensive dual-hormone treatment in type 1 diabetes possible.
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Affiliation(s)
- H K Reiband
- Department of Endocrinology, Copenhagen University Hospital, Hvidovre, Denmark
| | - S Schmidt
- Department of Endocrinology, Copenhagen University Hospital, Hvidovre, Denmark
- Danish Diabetes Academy, Odense University Hospital, Odense, Denmark
| | - A Ranjan
- Department of Endocrinology, Copenhagen University Hospital, Hvidovre, Denmark
- Danish Diabetes Academy, Odense University Hospital, Odense, Denmark
| | - J J Holst
- NNF Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - S Madsbad
- Department of Endocrinology, Copenhagen University Hospital, Hvidovre, Denmark
| | - K Nørgaard
- Department of Endocrinology, Copenhagen University Hospital, Hvidovre, Denmark
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Hieronymus L, Griffin S. Role of Amylin in Type 1 and Type 2 Diabetes. DIABETES EDUCATOR 2015; 41:47S-56S. [DOI: 10.1177/0145721715607642] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Purpose The pathophysiology of diabetes has historically focused on alterations in insulin secretion and function; however, diabetes involves multiple hormonal alterations, including abnormal regulation of amylin. This review discusses the physiologic functions of amylin in glucose homeostasis and the rationale for amylin replacement in type 1 and 2 diabetes. The use of pramlintide, a synthetic amylin analog, is also discussed. Conclusions Amylin, formed primarily in pancreatic islet β cells, is cosecreted with insulin in response to caloric intake. Patients with type 1 diabetes have lower baseline amylin serum concentrations, and amylin response to caloric intake is absent. Patients with type 2 diabetes requiring insulin also have a diminished amylin response to caloric intake, potentially related to the degree of β-cell impairment. Key physiologic functions of amylin in maintaining glucose homeostasis include suppressing glucagon release in response to caloric intake, delaying the rate of gastric emptying, and stimulating the satiety center in the brain to limit caloric intake. Pramlintide is indicated for adults with type 1 and 2 diabetes who have not achieved adequate glucose control despite optimal insulin therapy. As an adjunct to insulin therapy, pramlintide demonstrated significant reductions in A1C in patients with type 1 and 2 diabetes, with favorable effects on body weight. It is administered subcutaneously before each major meal. There is an increased risk of hypoglycemia with insulin when used in combination with pramlintide. Other adverse effects may include nausea, vomiting, anorexia, reduced appetite, and headache. Proper patient selection and education are essential to successful pramlintide use.
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Affiliation(s)
- Laura Hieronymus
- DiabetesCare & Communications, Lexington, KY, USA (Dr Hieronymus)
- Baptist Health-Lexington, KY, USA (Dr Griffin)
| | - Stacy Griffin
- DiabetesCare & Communications, Lexington, KY, USA (Dr Hieronymus)
- Baptist Health-Lexington, KY, USA (Dr Griffin)
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High Intensity Interval Training Improves Glycaemic Control and Pancreatic β Cell Function of Type 2 Diabetes Patients. PLoS One 2015; 10:e0133286. [PMID: 26258597 PMCID: PMC4530878 DOI: 10.1371/journal.pone.0133286] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 06/19/2015] [Indexed: 11/19/2022] Open
Abstract
Physical activity improves the regulation of glucose homeostasis in both type 2 diabetes (T2D) patients and healthy individuals, but the effect on pancreatic β cell function is unknown. We investigated glycaemic control, pancreatic function and total fat mass before and after 8 weeks of low volume high intensity interval training (HIIT) on cycle ergometer in T2D patients and matched healthy control individuals. Study design/method: Elderly (56 yrs±2), non-active T2D patients (n = 10) and matched (52 yrs±2) healthy controls (CON) (n = 13) exercised 3 times (10×60 sec. HIIT) a week over an 8 week period on a cycle ergometer. Participants underwent a 2-hour oral glucose tolerance test (OGTT). On a separate day, resting blood pressure measurement was conducted followed by an incremental maximal oxygen uptake ( V˙O2max) cycle ergometer test. Finally, a whole body dual X-ray absorptiometry (DXA) was performed. After 8 weeks of training, the same measurements were performed. Results: in the T2D-group, glycaemic control as determined by average fasting venous glucose concentration (p = 0.01), end point 2-hour OGTT (p = 0.04) and glycosylated haemoglobin (p = 0.04) were significantly reduced. Pancreatic homeostasis as determined by homeostatic model assessment of insulin resistance (HOMA-IR) and HOMA β cell function (HOMA-%β) were both significantly ameliorated (p = 0.03 and p = 0.03, respectively). Whole body insulin sensitivity as determined by the disposition index (DI) was significantly increased (p = 0.03). During OGTT, the glucose continuum was significantly reduced at -15 (p = 0.03), 30 (p = 0.03) and 120 min (p = 0.03) and at -10 (p = 0.003) and 0 min (p = 0.003) with an additional improvement (p = 0.03) of its 1st phase (30 min) area under curve (AUC). Significant abdominal fat mass losses were seen in both groups (T2D: p = 0.004 and CON: p = 0.02) corresponding to a percentage change of -17.84%±5.02 and -9.66%±3.07, respectively. Conclusion: these results demonstrate that HIIT improves overall glycaemic control and pancreatic β cell function in T2D patients. Additionally, both groups experienced abdominal fat mass losses. These findings demonstrate that HIIT is a health beneficial exercise strategy in T2D patients.
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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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Patarrão RS, Lautt WW, Macedo MP. Acute glucagon induces postprandial peripheral insulin resistance. PLoS One 2015; 10:e0127221. [PMID: 25961284 PMCID: PMC4427479 DOI: 10.1371/journal.pone.0127221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 04/13/2015] [Indexed: 11/18/2022] Open
Abstract
Glucagon levels are often moderately elevated in diabetes. It is known that glucagon leads to a decrease in hepatic glutathione (GSH) synthesis that in turn is associated with decreased postprandial insulin sensitivity. Given that cAMP pathway controls GSH levels we tested whether insulin sensitivity decreases after intraportal (ipv) administration of a cAMP analog (DBcAMP), and investigated whether glucagon promotes insulin resistance through decreasing hepatic GSH levels.Insulin sensitivity was determined in fed male Sprague-Dawley rats using a modified euglycemic hyperinsulinemic clamp in the postprandial state upon ipv administration of DBcAMP as well as glucagon infusion. Glucagon effects on insulin sensitivity was assessed in the presence or absence of postprandial insulin sensitivity inhibition by administration of L-NMMA. Hepatic GSH and NO content and plasma levels of NO were measured after acute ipv glucagon infusion. Insulin sensitivity was assessed in the fed state and after ipv glucagon infusion in the presence of GSH-E. We founf that DBcAMP and glucagon produce a decrease of insulin sensitivity, in a dose-dependent manner. Glucagon-induced decrease of postprandial insulin sensitivity correlated with decreased hepatic GSH content and was restored by administration of GSH-E. Furthermore, inhibition of postprandial decrease of insulin sensitivity L-NMMA was not overcome by glucagon, but glucagon did not affect hepatic and plasma levels of NO. These results show that glucagon decreases postprandial insulin sensitivity through reducing hepatic GSH levels, an effect that is mimicked by increasing cAMP hepatic levels and requires physiological NO levels. These observations support the hypothesis that glucagon acts via adenylate cyclase to decrease hepatic GSH levels and induce insulin resistance. We suggest that the glucagon-cAMP-GSH axis is a potential therapeutic target to address insulin resistance in pathological conditions.
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Affiliation(s)
- Rita S. Patarrão
- Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, Lisboa, Portugal
| | - W. Wayne Lautt
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - M. Paula Macedo
- Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, Lisboa, Portugal
- APDP-ERC Portuguese Diabetes AssociationEducationand Research Center, Rua do Salitre, Lisboa, Portugal
- * E-mail:
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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.
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Affiliation(s)
- B Ahrén
- Department of Clinical Sciences, Lund University, Lund, Sweden
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Vater A, Sell S, Kaczmarek P, Maasch C, Buchner K, Pruszynska-Oszmalek E, Kolodziejski P, Purschke WG, Nowak KW, Strowski MZ, Klussmann S. A mixed mirror-image DNA/RNA aptamer inhibits glucagon and acutely improves glucose tolerance in models of type 1 and type 2 diabetes. J Biol Chem 2013; 288:21136-21147. [PMID: 23744070 PMCID: PMC3774380 DOI: 10.1074/jbc.m112.444414] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 06/04/2013] [Indexed: 11/23/2022] Open
Abstract
Excessive secretion of glucagon, a functional insulin antagonist, significantly contributes to hyperglycemia in type 1 and type 2 diabetes. Accordingly, immunoneutralization of glucagon or genetic deletion of the glucagon receptor improved glucose homeostasis in animal models of diabetes. Despite this strong evidence, agents that selectively interfere with endogenous glucagon have not been implemented in clinical practice yet. We report the discovery of mirror-image DNA-aptamers (Spiegelmer®) that bind and inhibit glucagon. The affinity of the best binding DNA oligonucleotide was remarkably increased (>25-fold) by the introduction of oxygen atoms at selected 2'-positions through deoxyribo- to ribonucleotide exchanges resulting in a mixed DNA/RNA-Spiegelmer (NOX-G15) that binds glucagon with a Kd of 3 nm. NOX-G15 shows no cross-reactivity with related peptides such as glucagon-like peptide-1, glucagon-like peptide-2, gastric-inhibitory peptide, and prepro-vasoactive intestinal peptide. In vitro, NOX-G15 inhibits glucagon-stimulated cAMP production in CHO cells overexpressing the human glucagon receptor with an IC50 of 3.4 nm. A single injection of NOX-G15 ameliorated glucose excursions in intraperitoneal glucose tolerance tests in mice with streptozotocin-induced (type 1) diabetes and in a non-genetic mouse model of type 2 diabetes. In conclusion, the data suggest NOX-G15 as a therapeutic candidate with the potential to acutely attenuate hyperglycemia in type 1 and type 2 diabetes.
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MESH Headings
- Animals
- Aptamers, Nucleotide/blood
- Aptamers, Nucleotide/pharmacokinetics
- Aptamers, Nucleotide/pharmacology
- Aptamers, Nucleotide/therapeutic use
- Blood Glucose/metabolism
- Body Weight/drug effects
- CHO Cells
- Cricetinae
- Cricetulus
- Cyclic AMP/biosynthesis
- Diabetes Mellitus, Type 1/blood
- Diabetes Mellitus, Type 1/drug therapy
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/drug therapy
- Disease Models, Animal
- Fasting/blood
- Glucagon/antagonists & inhibitors
- Glucagon/metabolism
- Glucose Tolerance Test
- Humans
- Kinetics
- Male
- Mice
- Mice, Inbred BALB C
- RNA/metabolism
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Affiliation(s)
- Axel Vater
- From the NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Simone Sell
- From the NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Przemyslaw Kaczmarek
- the Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, 35 Wolynska Street, 60637 Poznan, Poland, and
| | - Christian Maasch
- From the NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Klaus Buchner
- From the NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Ewa Pruszynska-Oszmalek
- the Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, 35 Wolynska Street, 60637 Poznan, Poland, and
| | - Pawel Kolodziejski
- the Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, 35 Wolynska Street, 60637 Poznan, Poland, and
| | - Werner G Purschke
- From the NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Krzysztof W Nowak
- the Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, 35 Wolynska Street, 60637 Poznan, Poland, and
| | - Mathias Z Strowski
- the Department of Hepatology and Gastroenterology and Interdisciplinary Centre of Metabolism: Endocrinology, Diabetes and Metabolism, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Sven Klussmann
- From the NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany,.
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Gastrointestinal factors contribute to glucometabolic disturbances in nondiabetic patients with end-stage renal disease. Kidney Int 2013; 83:915-23. [PMID: 23325073 DOI: 10.1038/ki.2012.460] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Nondiabetic patients with end-stage renal disease (ESRD) have disturbed glucose metabolism, the underlying pathophysiology of which is unclear. To help elucidate this, we studied patients with ESRD and either normal or impaired glucose tolerance (10 each NGT or IGT, respectively) and 11 controls using an oral glucose tolerance test and an isoglycemic intravenous glucose infusion on separate days. Plasma glucose, insulin, glucagon, and incretin hormones were measured repeatedly, and gastrointestinal-mediated glucose disposal (GIGD) based on glucose amounts utilized, and incretin effect based on incremental insulin responses, were calculated. The GIGD was significantly reduced in both ESRD groups compared with controls. Incretin effects were 69% (controls), 55% (ESRD with NGT), and 41% (ESRD with IGT), with a significant difference between controls and ESRDs with IGT. Fasting concentrations of glucagon and incretin hormones were significantly increased in patients with ESRD. Glucagon suppression was significantly impaired in both groups with ESRD compared with controls, while the baseline-corrected incretin hormone responses were unaltered between groups. Thus, patients with ESRD had reduced GIGD, a diminished incretin effect in those with IGT, and severe fasting hyperglucagonemia that seemed irrepressible in response to glucose stimuli. These factors may contribute to disturbed glucose metabolism in ESRD.
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Glycemic control after total pancreatectomy for intraductal papillary mucinous neoplasm: an exploratory study. HPB SURGERY : A WORLD JOURNAL OF HEPATIC, PANCREATIC AND BILIARY SURGERY 2012; 2012:381328. [PMID: 22966212 PMCID: PMC3433133 DOI: 10.1155/2012/381328] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 07/03/2012] [Indexed: 01/08/2023]
Abstract
Background. Glycemic control following total pancreatectomy (TP) has been thought to be difficult to manage. Diffuse intraductal papillary mucinous neoplasm (IPMN) is a potentially curable precursor to pancreatic adenocarcinoma, best treated by TP. Objective. Compare glycemic control in patients undergoing TP for IPMN to patients with type 1 diabetes mellitus (DM). Design/Setting. Retrospective cohort. Outcome Measure. Hemoglobin A1C(HbA1C) at 6, 12, 18, and 24 months after TP. In the control group, baseline was defined as 6 months prior to the first HbA1c measure. Results. Mean HgbA1C at each point of interest was similar between TP and type I DM patients (6 months (7.5% versus 7.7%, P = 0.52), 12 months (7.3% versus 8.0%, P = 0.081), 18 months (7.7% and 7.6%, P = 0.64), and at 24 months (7.3% versus 7.8%, P = 0.10)). Seven TP patients (50%) experienced a hypoglycemic event compared to 65 type 1 DM patients (65%, P = 0.38). Limitations. Small number of TP patients, retrospective design, lack of long-termfollowup. Conclusion. This suggests that glycemic control following TP for IPMNcan be well managed, similar to type 1 DM patients. Fear of DM following TP for IPMN should not preclude surgery when TP is indicated.
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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.
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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.
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Shen XX, Li HL, Pan L, Hong J, Xiao J, Hermansen K, Jeppesen PB, Li GW. Glucotoxicity and α cell dysfunction: involvement of the PI3K/Akt pathway in glucose-induced insulin resistance in rat islets and clonal αTC1-6 cells. Endocr Res 2012; 37:12-24. [PMID: 22007944 DOI: 10.3109/07435800.2011.610855] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIM/HYPOTHESIS The objective of this study was to assess how long-term exposure to high glucose affects the α cell function and whether the increased glucagon secretion is mediated via insulin resistance. MATERIALS AND METHODS We established a β cell-depleted rat model to obtain pure primary α cells. Furthermore, isolated rat islets and TC1-6 cells (a clonal α cell line) were exposed to high glucose (25 or 30 mmol/L) and low glucose (5.5 mmol/L) for up to 5 days to evaluate the influence of chronic glucose toxicity on glucagon secretion and glucagon gene expression. Moreover, we added insulin and/or Wortmannin to examine if the inhibitory effect of insulin on glucagon secretion was impaired by high glucose via the phosphatidylinositol 3 kinase/PKB protein kinase B pathway. RESULTS Both glucagon secretion and glucagon gene expression were increased in response to 5 days exposure to high glucose. While a moderate insulin concentration slightly inhibits glucagon secretion from rat islets and α TC1-6 cells at high glucose, a pronounced increase in glucagon secretion was observed at low glucose. We found that the insulin-mediated activity of the phosphatidylinositol 3 kinase/PKB protein kinase B pathway in the α cell was markedly impaired by chronic exposure to high glucose. CONCLUSION The hypersecretion of glucagon induced by glucotoxicity may be secondary to insulin resistance of the α cell induced by impaired activity of the insulin signaling pathway.
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Affiliation(s)
- Xiao-Xia Shen
- Endocrinology and Cardiac Disease Clinical Center, Fuwai Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, PR China.
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The complex exocrine-endocrine relationship and secondary diabetes in exocrine pancreatic disorders. J Clin Gastroenterol 2011; 45:850-61. [PMID: 21897283 DOI: 10.1097/mcg.0b013e31822a2ae5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The pancreas is a dual organ with exocrine and endocrine functions. The interrelationship of the endocrine-exocrine parts of the pancreas is a complex one, but recent clinical and experimental studies have expanded our knowledge. Many disorders primarily of the exocrine pancreas, often solely in the clinical realm of gastroenterologists are associated with diabetes mellitus (DM). Although, the DM becoming disorders are often grouped with type 2 diabetes, the pathogenesis, clinical manifestations and management differ. We review here data on the association of exocrine-endocrine pancreas, the many hormones of the pancreas and their possible effects on the exocrine functions followed by data on the epidemiology, pathogenesis, and management of DM in chronic pancreatitis, cystic fibrosis, pancreatic cancer, and clinical states after pancreatic surgery.
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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.
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Affiliation(s)
- J Mu
- Merck, RY80N-A58, 126 East Lincoln Avenue, Rahway, NJ, USA.
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Triplitt C, Cersosimo E, DeFronzo RA. Pioglitazone and alogliptin combination therapy in type 2 diabetes: a pathophysiologically sound treatment. Vasc Health Risk Manag 2010; 6:671-90. [PMID: 20859539 PMCID: PMC2941781 DOI: 10.2147/vhrm.s4852] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Indexed: 01/11/2023] Open
Abstract
Insulin resistance and islet (beta and alpha) cell dysfunction are major pathophysiologic abnormalities in type 2 diabetes mellitus (T2DM). Pioglitazone is a potent insulin sensitizer, improves pancreatic beta cell function and has been shown in several outcome trials to lower the risk of atherosclerotic and cardiovascular events. Glucagon-like peptide-1 deficiency/resistance contributes to islet cell dysfunction by impairing insulin secretion and increasing glucagon secretion. Dipeptidyl peptidase-4 (DPP-4) inhibitors improve pancreatic islet function by augmenting glucose-dependent insulin secretion and decreasing elevated plasma glucagon levels. Alogliptin is a new DPP-4 inhibitor that reduces glycosylated hemoglobin (HbA1c), is weight neutral, has an excellent safety profile, and can be used in combination with oral agents and insulin. Alogliptin has a low risk of hypoglycemia, and serious adverse events are uncommon. An alogliptin–pioglitazone combination is advantageous because it addresses both insulin resistance and islet dysfunction in T2DM. HbA1c reductions are significantly greater than with either monotherapy. This once-daily oral combination medication does not increase the risk of hypoglycemia, and tolerability and discontinuation rates do not differ significantly from either monotherapy. Importantly, measures of beta cell function and health are improved beyond that observed with either monotherapy, potentially improving durability of HbA1c reduction. The alogliptin–pioglitazone combination represents a pathophysiologically sound treatment of T2DM.
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Affiliation(s)
- Curtis Triplitt
- Diabetes Division, Department of Medicine, University of Texas, Health Science Center at San Antonio, San Antonio, Texas 78229-3900, USA
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Le Marchand SJ, Piston DW. Glucose suppression of glucagon secretion: metabolic and calcium responses from alpha-cells in intact mouse pancreatic islets. J Biol Chem 2010; 285:14389-98. [PMID: 20231269 DOI: 10.1074/jbc.m109.069195] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glucagon is released from alpha-cells present in intact pancreatic islets at glucose concentrations below 4 mm, whereas higher glucose levels inhibit its secretion. The mechanisms underlying the suppression of alpha-cell secretory activity are poorly understood, but two general types of models have been proposed as follows: direct inhibition by glucose or paracrine inhibition from non-alpha-cells within the islet of Langerhans. To identify alpha-cells for analysis, we utilized transgenic mice expressing fluorescent proteins targeted specifically to these cells. Measurements of glucagon secretion from pure populations of flow-sorted alpha-cells show that contrary to its effect on intact islets, glucose does stimulate glucagon secretion from isolated alpha-cells. This observation argues against a direct inhibition of glucagon secretion by glucose and supports the paracrine inhibition model. Imaging of cellular metabolism by two-photon excitation of NAD(P)H autofluorescence indicates that glucose is metabolized in alpha-cells and that glucokinase is the likely rate-limiting step in this process. Imaging calcium dynamics of alpha-cells in intact islets reveals that inhibiting concentrations of glucose increase the intracellular calcium concentration and the frequency of alpha-cell calcium oscillations. Application of candidate paracrine inhibitors leads to reduced glucagon secretion but did not decrease the alpha-cell calcium activity. Taken together, the data suggest that suppression occurs downstream from alpha-cell calcium signaling, presumably at the level of vesicle trafficking or exocytotic machinery.
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Affiliation(s)
- Sylvain J Le Marchand
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37232, USA
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Lau DC. Of Mentors and Mentoring. Can J Diabetes 2010. [DOI: 10.1016/s1499-2671(10)43003-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Maeda H, Okabayashi T, Yatabe T, Yamashita K, Hanazaki K. Perioperative intensive insulin therapy using artificial endocrine pancreas in patients undergoing pancreatectomy. World J Gastroenterol 2009; 15:4111-5. [PMID: 19725142 PMCID: PMC2738804 DOI: 10.3748/wjg.15.4111] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Perioperative glycemic control is important for reducing postoperative infectious complications. However, clinical trials have shown that efforts to maintain normoglycemia in intensive care unit patients result in deviation of glucose levels from the optimal range, and frequent attacks of hypoglycemia. Tight glycemic control is even more challenging in those undergoing pancreatic resection. Removal of lesions and surrounding normal pancreatic tissue often cause hormone deficiencies that lead to the destruction of glucose homeostasis, which is termed pancreatogenic diabetes. Pancreatogenic diabetes is characterized by the occurrence of hyperglycemia and iatrogenic severe hypoglycemia, which adversely effects patient recovery. Postoperatively, a variety of factors including surgical stress, inflammatory cytokines, sympathomimetic drug therapy, and aggressive nutritional support can also affect glycemic control. This review discusses the endocrine aspects of pancreatic resection and highlights postoperative glycemic control using a closed-loop system or artificial pancreas. In previous experiments, we have demonstrated the reliability of the artificial pancreas in dogs with total pancreatectomy, and its postoperative clinical use has been shown to be effective and safe, without the occurrence of hypoglycemic episodes, even in patients after total pancreatectomy. Considering the increasing requirement for tight perioperative glycemic control and the recognized risk of hypoglycemia, we propose the use of an artificial endocrine pancreas that is able to monitor continuously blood glucose concentrations with proven accuracy, and administer automatically substances to return blood glucose concentration to the optimal narrow range.
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