101
|
Rivero-Gutierrez B, Haller A, Holland J, Yates E, Khrisna R, Habegger K, Dimarchi R, D'Alessio D, Perez-Tilve D. Deletion of the glucagon receptor gene before and after experimental diabetes reveals differential protection from hyperglycemia. Mol Metab 2018; 17:28-38. [PMID: 30170980 PMCID: PMC6197675 DOI: 10.1016/j.molmet.2018.07.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/26/2018] [Accepted: 07/31/2018] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE Mice with congenital loss of the glucagon receptor gene (Gcgr-/- mice) remain normoglycemic in insulinopenic conditions, suggesting that unopposed glucagon action is the driving force for hyperglycemia in Type-1 Diabetes Mellitus (T1DM). However, chronic loss of GCGR results in a neomorphic phenotype that includes hormonal signals with hypoglycemic activity. We combined temporally-controlled GCGR deletion with pharmacological treatments to dissect the direct contribution of GCGR signaling to glucose control in a common mouse model of T1DM. METHODS We induced experimental T1DM by injecting the beta-cell cytotoxin streptozotocin (STZ) in mice with congenital or temporally-controlled Gcgr loss-of-function using tamoxifen (TMX). RESULTS Disruption of Gcgr expression, using either an inducible approach in adult mice or animals with congenital knockout, abolished the response to a long-acting Gcgr agonist. Mice with either developmental Gcgr disruption or inducible deletion several weeks before STZ treatment maintained normoglycemia. However, mice with inducible knockout of the Gcgr one week after the onset of STZ diabetes had only partial correction of hyperglycemia, an effect that was reversed by GLP-1 receptor blockade. Mice with Gcgr deletion for either 2 or 6 weeks had similar patterns of gene expression, although the changes were generally larger with longer GCGR knockout. CONCLUSIONS These findings demonstrate that the effects of glucagon to mitigate diabetic hyperglycemia are not through acute signaling but require compensations that take weeks to develop.
Collapse
Affiliation(s)
- Belen Rivero-Gutierrez
- Department of Internal Medicine, University of Cincinnati, 2180 E. Galbraith Rd, Cincinnati, OH, USA
| | - April Haller
- Department of Internal Medicine, University of Cincinnati, 2180 E. Galbraith Rd, Cincinnati, OH, USA
| | - Jenna Holland
- Department of Internal Medicine, University of Cincinnati, 2180 E. Galbraith Rd, Cincinnati, OH, USA
| | - Emily Yates
- Department of Internal Medicine, University of Cincinnati, 2180 E. Galbraith Rd, Cincinnati, OH, USA
| | - Radha Khrisna
- Department of Medicine, Duke University School of Medicine, NC, USA
| | - Kirk Habegger
- Comprehensive Diabetes Center and Department of Medicine - Endocrinology, Diabetes & and Metabolism, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Richard Dimarchi
- Novo Nordisk Research Center Indianapolis, Indianapolis, IN, USA; Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - David D'Alessio
- Department of Medicine, Duke University School of Medicine, NC, USA
| | - Diego Perez-Tilve
- Department of Internal Medicine, University of Cincinnati, 2180 E. Galbraith Rd, Cincinnati, OH, USA.
| |
Collapse
|
102
|
Gild ML, Tsang V, Samra J, Clifton-Bligh RJ, Tacon L, Gill AJ. Hypercalcemia in Glucagon Cell Hyperplasia and Neoplasia (Mahvash Syndrome): A New Association. J Clin Endocrinol Metab 2018; 103:3119-3123. [PMID: 30032256 DOI: 10.1210/jc.2018-01074] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/13/2018] [Indexed: 12/28/2022]
Abstract
CONTEXT Hyperglucagonemia in the absence of glucagonomas is rare. Biallelic-inactivating mutations in the glucagon receptor gene (GCGR) cause glucagon cell hyperplasia and neoplasia (GCHN), also termed Mahvash syndrome. Here, we report the first case to our knowledge of GCHN presenting with hypercalcemia and demonstrate a unique relationship between calcium and α-cell hyperplasia. CASE DESCRIPTION A 47-year-old man presented with severe PTH-independent hypercalcemia, 13.95 mg/dL (3.48 mmol/L). Imaging and extensive pathology tests yielded no conclusive cause. Glucagon levels >300 times the upper limit of normal were discovered. Subtotal pancreatectomy identified α-cell hyperplasia and neoplasia with metastatic disease in lymph nodes. Genomic analysis confirmed a homozygous missense variant in GCGR (Asp63Asn). This is a previously described pathologic variant and has a known association with GCHN. CONCLUSIONS Inactivating mutations of the glucagon receptor gene lead to nonfunctional hyperglucagonemia and are associated with GCHN. Homozygous or compound heterozygous GCGR mutations are associated with α-cell hyperplasia, a known precursor to pancreatic neuroendocrine tumors that can metastasize. Hypercalcemia is an unreported consequence of GCHN with an unclear mechanism.
Collapse
Affiliation(s)
- Matti L Gild
- Department of Endocrinology and Diabetes, Royal North Shore Hospital, St Leonards, New South Wales, Australia
- University of Sydney, Sydney, New South Wales, Australia
| | - Venessa Tsang
- Department of Endocrinology and Diabetes, Royal North Shore Hospital, St Leonards, New South Wales, Australia
- University of Sydney, Sydney, New South Wales, Australia
| | - Jaswinder Samra
- University of Sydney, Sydney, New South Wales, Australia
- Department of Surgery, Royal North Shore Hospital, St. Leonards, New South Wales, Australia
| | - Roderick J Clifton-Bligh
- Department of Endocrinology and Diabetes, Royal North Shore Hospital, St Leonards, New South Wales, Australia
- University of Sydney, Sydney, New South Wales, Australia
| | - Lyndal Tacon
- Department of Endocrinology and Diabetes, Royal North Shore Hospital, St Leonards, New South Wales, Australia
- University of Sydney, Sydney, New South Wales, Australia
| | - Anthony J Gill
- University of Sydney, Sydney, New South Wales, Australia
- Cancer Diagnosis and Pathology Group, Kolling Institute of Medical Research, Royal North Shore Hospital, St. Leonards, New South Wales, Australia
| |
Collapse
|
103
|
Role of mTOR in Glucose and Lipid Metabolism. Int J Mol Sci 2018; 19:ijms19072043. [PMID: 30011848 PMCID: PMC6073766 DOI: 10.3390/ijms19072043] [Citation(s) in RCA: 157] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/10/2018] [Accepted: 07/11/2018] [Indexed: 02/06/2023] Open
Abstract
The mammalian target of rapamycin, mTOR is the master regulator of a cell’s growth and metabolic state in response to nutrients, growth factors and many extracellular cues. Its dysregulation leads to a number of metabolic pathological conditions, including obesity and type 2 diabetes. Here, we review recent findings on the role of mTOR in major metabolic organs, such as adipose tissues, liver, muscle, pancreas and brain. And their potentials as the mTOR related pharmacological targets will be also discussed.
Collapse
|
104
|
Karanth S, Adams JD, Serrano MDLA, Quittner-Strom EB, Simcox J, Villanueva CJ, Ozcan L, Holland WL, Yost HJ, Vella A, Schlegel A. A Hepatocyte FOXN3-α Cell Glucagon Axis Regulates Fasting Glucose. Cell Rep 2018; 24:312-319. [PMID: 29996093 DOI: 10.1016/j.celrep.2018.06.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 05/07/2018] [Accepted: 06/08/2018] [Indexed: 01/26/2023] Open
Abstract
The common genetic variation at rs8004664 in the FOXN3 gene is independently and significantly associated with fasting blood glucose, but not insulin, in non-diabetic humans. Recently, we reported that primary hepatocytes from rs8004664 hyperglycemia risk allele carriers have increased FOXN3 transcript and protein levels and liver-limited overexpression of human FOXN3, a transcriptional repressor that had not been implicated in metabolic regulation previously, increases fasting blood glucose in zebrafish. Here, we find that injection of glucagon into mice and adult zebrafish decreases liver Foxn3 protein and transcript levels. Zebrafish foxn3 loss-of-function mutants have decreased fasting blood glucose, blood glucagon, liver gluconeogenic gene expression, and α cell mass. Conversely, liver-limited overexpression of foxn3 increases α cell mass. Supporting these genetic findings in model organisms, non-diabetic rs8004664 risk allele carriers have decreased suppression of glucagon during oral glucose tolerance testing. By reciprocally regulating each other, liver FOXN3 and glucagon control fasting glucose.
Collapse
Affiliation(s)
- Santhosh Karanth
- University of Utah Molecular Medicine Program, University of Utah School of Medicine, Salt Lake City, UT, USA; Department of Internal Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - J D Adams
- Department of Internal Medicine, Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Maria de Los Angeles Serrano
- University of Utah Molecular Medicine Program, University of Utah School of Medicine, Salt Lake City, UT, USA; Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Ezekiel B Quittner-Strom
- University of Utah Molecular Medicine Program, University of Utah School of Medicine, Salt Lake City, UT, USA; Department of Nutrition and Integrative Physiology, University of Utah College of Health, Salt Lake City, UT, USA
| | - Judith Simcox
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Claudio J Villanueva
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Lale Ozcan
- Department of Medicine, Division of Molecular Medicine, Columbia University Medical Center, New York, NY, USA
| | - William L Holland
- University of Utah Molecular Medicine Program, University of Utah School of Medicine, Salt Lake City, UT, USA; Department of Nutrition and Integrative Physiology, University of Utah College of Health, Salt Lake City, UT, USA; Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - H Joseph Yost
- University of Utah Molecular Medicine Program, University of Utah School of Medicine, Salt Lake City, UT, USA; Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, UT, USA; Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Adrian Vella
- Department of Internal Medicine, Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Amnon Schlegel
- University of Utah Molecular Medicine Program, University of Utah School of Medicine, Salt Lake City, UT, USA; Department of Internal Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Utah School of Medicine, Salt Lake City, UT, USA; Department of Nutrition and Integrative Physiology, University of Utah College of Health, Salt Lake City, UT, USA; Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA.
| |
Collapse
|
105
|
Knop FK. EJE PRIZE 2018: A gut feeling about glucagon. Eur J Endocrinol 2018; 178:R267-R280. [PMID: 29678923 DOI: 10.1530/eje-18-0197] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/13/2018] [Indexed: 12/31/2022]
Abstract
Hyperglucagonaemia (in the fasting as well as in the postprandial state) is considered a core pathophysiological component of diabetes and is found to contribute substantially to the hyperglycaemic state of diabetes. Hyperglucagonaemia is usually viewed upon as a consequence of pancreatic alpha cell insensitivity to the glucagon-suppressive effects of glucose and insulin. Since we observed that the well-known hyperglucagonaemic response to oral glucose in patients with type 2 diabetes is exchanged by normal suppression of plasma glucagon levels following isoglycaemic intravenous glucose administration in these patients, we have been focusing on the gut and gut-derived factors as potential mediators of diabetic hyperglucagonaemia. In a series of clinical experiments, we have elucidated the role of gut-derived factors in diabetic hyperglucagonaemia and shown that glucose-dependent insulinotropic polypeptide promotes hyperglucagonaemia and that glucagon, hitherto considered a pancreas-specific hormone, may also be secreted from extrapancreatic tissues - most likely from proglucagon-producing enteroendocrine cells. Furthermore, our observation that fasting hyperglucagonaemia is unrelated to the diabetic state, but strongly correlates with obesity, liver fat content and circulating amino acids, has made us question the common 'pancreacentric' and 'glucocentric' understanding of hyperglucagonaemia and led to the hypothesis that steatosis-induced hepatic glucagon resistance (and reduced amino acid turnover) and compensatory glucagon secretion mediated by increased circulating amino acids constitute a complete endocrine feedback system: the liver-alpha cell axis. This article summarises the physiological regulation of glucagon secretion in humans and considers new findings suggesting that the liver and the gut play key roles in determining fasting and postabsorptive circulating glucagon levels.
Collapse
Affiliation(s)
- Filip K Knop
- Clinical Metabolic PhysiologySteno Diabetes Center Copenhagen, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
- Department of Clinical Medicine Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic ResearchFaculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
106
|
|
107
|
Esterline RL, Vaag A, Oscarsson J, Vora J. MECHANISMS IN ENDOCRINOLOGY: SGLT2 inhibitors: clinical benefits by restoration of normal diurnal metabolism? Eur J Endocrinol 2018; 178:R113-R125. [PMID: 29371333 DOI: 10.1530/eje-17-0832] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/19/2018] [Indexed: 12/26/2022]
Abstract
Type 2 diabetes (T2D) is associated with inhibition of autophagic and lysosomal housekeeping processes that detrimentally affect key organ functioning; a process likely to be exacerbated by conventional insulin-driven anabolic therapies. We propose that the cardio-renal benefits demonstrated with sodium-glucose cotransporter-2 inhibitor (SGLT2i) treatment in T2D partly may be explained by their ability to drive consistent, overnight periods of increased catabolism brought about by constant glucosuria. Key steps driving this catabolic mechanism include: a raised glucagon/insulin ratio initially depleting glycogen in the liver and ultimately activating gluconeogenesis utilizing circulating amino acids (AAs); a general fuel switch from glucose to free fatty acids (accompanied by a change in mitochondrial morphology from a fission to a sustained fusion state driven by a decrease in AA levels); a decrease in circulating AAs and insulin driving inhibition of mammalian target of rapamycin complex 1 (mTORC1), which enhances autophagy/lysosomal degradation of dysfunctional organelles, eventually causing a change in mitochondrial morphology from a fission to a sustained fusion state. Resumption of eating in the morning restores anabolic biogenesis of new and fully functional organelles and proteins. Restoration of diurnal metabolic rhythms and flexibility by SGLT2is may have therapeutic implications beyond those already demonstrated for the cardio-renal axis and may therefore affect other non-diabetes disease states.
Collapse
Affiliation(s)
| | - Allan Vaag
- Cardiovascular and Metabolic Disease (CVMD) Translational Medicine Unit, Early Clinical Development, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Jan Oscarsson
- AstraZeneca Pharmaceuticals, Gaithersburg, Maryland, USA
| | - Jiten Vora
- Royal Liverpool University Hospital, University of Liverpool, Liverpool, UK
| |
Collapse
|
108
|
Abstract
The lobules are the functional units of the liver. They consist of 15–25 layers of hepatocytes with specialized metabolic functions and gene expression patterns relative to their position along the lobule, a phenomenon referred to as metabolic zonation. The Wnt/β-catenin pathway regulates hepatocyte function but how the zonation is controlled to meet the metabolic demands of the liver is unclear. Glucagon regulates hepatic function. We now demonstrate that glucagon contributes to liver zonation by interacting and opposing the actions of the Wnt/β-catenin pathway. Liver zonation characterizes the separation of metabolic pathways along the lobules and is required for optimal function. Wnt/β-catenin signaling controls metabolic zonation by activating genes in the perivenous hepatocytes, while suppressing genes in the periportal counterparts. We now demonstrate that glucagon opposes the actions of Wnt/β-catenin signaling on gene expression and metabolic zonation pattern. The effects were more pronounced in the periportal hepatocytes where 28% of all genes were activated by glucagon and inhibited by Wnt/β-catenin. The glucagon and Wnt/β-catenin receptors and their signaling pathways are uniformly distributed in periportal and perivenous hepatocytes and the expression is not regulated by the opposing signal. Collectively, our results show that glucagon controls gene expression and metabolic zonation in the liver through a counterplay with the Wnt/β-catenin signaling pathway.
Collapse
|
109
|
Wewer Albrechtsen NJ, Færch K, Jensen TM, Witte DR, Pedersen J, Mahendran Y, Jonsson AE, Galsgaard KD, Winther-Sørensen M, Torekov SS, Lauritzen T, Pedersen O, Knop FK, Hansen T, Jørgensen ME, Vistisen D, Holst JJ. Evidence of a liver-alpha cell axis in humans: hepatic insulin resistance attenuates relationship between fasting plasma glucagon and glucagonotropic amino acids. Diabetologia 2018; 61:671-680. [PMID: 29305624 DOI: 10.1007/s00125-017-4535-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 11/23/2017] [Indexed: 12/14/2022]
Abstract
AIMS/HYPOTHESIS The secretion of glucagon is controlled by blood glucose and inappropriate secretion of glucagon contributes to hyperglycaemia in diabetes. Besides its role in glucose regulation, glucagon regulates amino acid metabolism in hepatocytes by increasing ureagenesis. Disruption of this mechanism causes hyperaminoacidaemia, which in turn increases glucagon secretion. We hypothesised that hepatic insulin resistance (secondary to hepatic steatosis) via defective glucagon signalling/glucagon resistance would lead to impaired ureagenesis and, hence, increased plasma concentrations of glucagonotropic amino acids and, subsequently, glucagon. METHODS To examine the association between glucagon and amino acids, and to explore whether this relationship was modified by hepatic insulin resistance, we studied a well-characterised cohort of 1408 individuals with normal and impaired glucose regulation. In this cohort, we have previously reported insulin resistance to be accompanied by increased plasma concentrations of glucagon. We now measure plasma levels of amino acids in the same cohort. HOMA-IR was calculated as a marker of hepatic insulin resistance. RESULTS Fasting levels of glucagonotropic amino acids and glucagon were significantly and inversely associated in linear regression models (persisting after adjustment for age, sex and BMI). Increasing levels of hepatic, but not peripheral insulin resistance (p > 0.166) attenuated the association between glucagon and circulating levels of alanine, glutamine and tyrosine, and was significantly associated with hyperaminoacidaemia and hyperglucagonaemia. A doubling of the calculated glucagon-alanine index was significantly associated with a 30% increase in hepatic insulin resistance, a 7% increase in plasma alanine aminotransferase levels, and a 14% increase in plasma γ-glutamyltransferase levels. CONCLUSIONS/INTERPRETATION This cross-sectional study supports the existence of a liver-alpha cell axis in humans: glucagon regulates plasma levels of amino acids, which in turn feedback to regulate the secretion of glucagon. With hepatic insulin resistance, reflecting hepatic steatosis, the feedback cycle is disrupted, leading to hyperaminoacidaemia and hyperglucagonaemia. The glucagon-alanine index is suggested as a relevant marker for hepatic glucagon signalling.
Collapse
Affiliation(s)
- Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Daniel R Witte
- The Danish Diabetes Academy, Odense, Denmark
- Department of Public Health, Section of General Practice, Aarhus University, Aarhus, Denmark
| | - Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yuvaraj Mahendran
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anna E Jonsson
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katrine D Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marie Winther-Sørensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Signe S Torekov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Torsten Lauritzen
- Department of Public Health, Section of General Practice, Aarhus University, Aarhus, Denmark
| | - Oluf Pedersen
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Filip K Knop
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Torben Hansen
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marit E Jørgensen
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
- National Institute of Public Health, Southern Denmark University, Odense, Denmark
| | | | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
110
|
Ardestani A, Lupse B, Kido Y, Leibowitz G, Maedler K. mTORC1 Signaling: A Double-Edged Sword in Diabetic β Cells. Cell Metab 2018; 27:314-331. [PMID: 29275961 DOI: 10.1016/j.cmet.2017.11.004] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/11/2017] [Accepted: 11/15/2017] [Indexed: 12/21/2022]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is a central regulator of metabolic and nutrient cues that integrates environmental inputs into downstream signaling pathways to control cellular metabolism, growth, and survival. While numerous in vitro and in vivo studies reported the positive functions of mTORC1 in the regulation of β cell survival and proliferation under physiological conditions, more recent work demonstrates the opposite in the long term; this is exemplified by the constitutive inappropriate hyper-activation of mTORC1 in diabetic islets or β cells under conditions of increased β cell stress and metabolic demands. These recent findings uncover mTORC1's importance as an emerging significant player in the development and progression of β cell failure in type 2 diabetes and suggest that mTORC1 may act as a "double edge sword" in the regulation of β cell mass and function in response to metabolic stress such as nutrient overload and insulin resistance.
Collapse
Affiliation(s)
- Amin Ardestani
- University of Bremen, Centre for Biomolecular Interactions Bremen, Bremen 28359, Germany.
| | - Blaz Lupse
- University of Bremen, Centre for Biomolecular Interactions Bremen, Bremen 28359, Germany
| | - Yoshiaki Kido
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan; Division of Metabolism and Disease, Department of Biophysics, Kobe University Graduate School of Health Sciences, Kobe 654-0142, Japan
| | - Gil Leibowitz
- Endocrinology and Metabolism Service and the Hadassah Diabetes Unit, Department of Medicine, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Kathrin Maedler
- University of Bremen, Centre for Biomolecular Interactions Bremen, Bremen 28359, Germany.
| |
Collapse
|
111
|
Wewer Albrechtsen NJ. Glucagon receptor signaling in metabolic diseases. Peptides 2018; 100:42-47. [PMID: 29412830 DOI: 10.1016/j.peptides.2017.11.016] [Citation(s) in RCA: 20] [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] [Received: 09/27/2017] [Revised: 11/23/2017] [Accepted: 11/24/2017] [Indexed: 01/25/2023]
Abstract
Glucagon is a peptide hormone secreted from the pancreatic alpha cells in response to hypoglycemia but in some patients with type 2 diabetes a paradoxical hypersecretion results from the intake of glucose. In rodent, antagonizing the actions of glucagon have been shown to be effective for lowering blood glucose levels and this has recently have been solidified in patients with type 2 diabetes. Although the reported increases of liver enzymes, hyperglucagonemia, and alpha cell hyperplasia resulting from glucagon receptor antagonism may potentially limit the clinical applicability of glucagon receptor antagonists, they may serve as an instrumental toolbox for delineating the physiology of glucagon. Agonizing glucagon receptor signaling may be relevant, in particular when combined with glucagon-like peptide-1 receptor analogues in the perspective of body weight lowering therapy. Here, we will focus on new conceptual aspects of glucagon biology and how this may led to new diagnostics and treatment of metabolic diseases.
Collapse
Affiliation(s)
- Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Novo Nordisk Foundation Center for Basic Metabolic Research, and the Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
| |
Collapse
|
112
|
Nunez DJ, D'Alessio D. Glucagon receptor as a drug target: A witches' brew of eye of newt (peptides) and toe of frog (receptors). Diabetes Obes Metab 2018; 20:233-237. [PMID: 28842950 DOI: 10.1111/dom.13102] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 12/16/2022]
MESH Headings
- Animals
- Antibodies, Monoclonal/adverse effects
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Monoclonal, Humanized
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/metabolism
- Drugs, Investigational/adverse effects
- Drugs, Investigational/pharmacology
- Drugs, Investigational/therapeutic use
- Glucagon-Like Peptide-1 Receptor/agonists
- Glucagon-Like Peptide-1 Receptor/metabolism
- Humans
- Hypoglycemic Agents/adverse effects
- Hypoglycemic Agents/pharmacology
- Hypoglycemic Agents/therapeutic use
- Molecular Targeted Therapy
- Receptors, Glucagon/agonists
- Receptors, Glucagon/antagonists & inhibitors
- Receptors, Glucagon/metabolism
- Signal Transduction/drug effects
Collapse
Affiliation(s)
- Derek J Nunez
- Division of Endocrinology, Metabolism and Nutrition, Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, North Carolina
| | - David D'Alessio
- Division of Endocrinology, Metabolism and Nutrition, Duke Molecular Physiology Institute, Duke University School of Medicine, Durham, North Carolina
| |
Collapse
|
113
|
Gasbjerg LS, Christensen MB, Hartmann B, Lanng AR, Sparre-Ulrich AH, Gabe MBN, Dela F, Vilsbøll T, Holst JJ, Rosenkilde MM, Knop FK. GIP(3-30)NH 2 is an efficacious GIP receptor antagonist in humans: a randomised, double-blinded, placebo-controlled, crossover study. Diabetologia 2018; 61:413-423. [PMID: 28948296 DOI: 10.1007/s00125-017-4447-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 08/09/2017] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESIS Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone secreted postprandially from enteroendocrine K cells, but despite therapeutically interesting effects, GIP physiology in humans remains incompletely understood. Progress in this field could be facilitated by a suitable GIP receptor antagonist. For the first time in humans, we investigated the antagonistic properties of the naturally occurring GIP(3-30)NH2 in in vivo and in in vitro receptor studies. METHODS In transiently transfected COS-7 cells, GIP(3-30)NH2 was evaluated with homologous receptor binding and receptor activation (cAMP accumulation) studies at the glucagon-like peptide 1 (GLP-1), glucagon-like peptide-2 (GLP-2), glucagon, secretin and growth hormone-releasing hormone (GHRH) receptors. Ten healthy men (eligibility criteria: age 20-30 years, HbA1c less than 6.5% [48 mmol/mol] and fasting plasma glucose [FPG] less than 7 mmol/l) were included in the clinical study. Data were collected as plasma and serum samples from a cubital vein cannula. As primary outcome, insulin secretion and glucose requirements were evaluated together with in a randomised, four-period, crossover design by infusing GIP(3-30)NH2 (800 pmol kg-1 min-1), GIP (1.5 pmol kg-1 min-1), a combination of these or placebo during hyperglycaemic clamp experiments. The content of the infusions were blinded to the study participants and experimental personnel. No study participants dropped out. RESULTS GIP(3-30)NH2 neither bound, stimulated nor antagonised a series of related receptors in vitro. The elimination plasma half-life of GIP(3-30)NH2 in humans was 7.6 ± 1.4 min. Markedly larger amounts of glucose were required to maintain the clamp during GIP infusion compared with the other days. GIP-induced insulin secretion was reduced by 82% (p < 0.0001) during co-infusion with GIP(3-30)NH2, and the need for glucose was reduced to placebo levels. There were no effects of GIP(3-30)NH2 alone or of GIP with or without GIP(3-30)NH2 on plasma glucagon, GLP-1, somatostatin, triacylglycerols, cholesterol, glycerol or NEFA. GIP(3-30)NH2 administration was well tolerated and without side effects. CONCLUSIONS/INTERPRETATION We conclude that GIP(3-30)NH2 is an efficacious and specific GIP receptor antagonist in humans suitable for studies of GIP physiology and pathophysiology. TRIAL REGISTRATION ClinicalTrials.gov registration no. NCT02747472. FUNDING The study was funded by Gangstedfonden, the European Foundation for the Study of Diabetes, and Aase og Ejnar Danielsens fond.
Collapse
Affiliation(s)
- Lærke S Gasbjerg
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Kildegårdsvej 28, 2900, Hellerup, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mikkel B Christensen
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Kildegårdsvej 28, 2900, Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Pharmacology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Amalie R Lanng
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Kildegårdsvej 28, 2900, Hellerup, Denmark
| | - Alexander H Sparre-Ulrich
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maria B N Gabe
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Flemming Dela
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Geriatrics, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Tina Vilsbøll
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Kildegårdsvej 28, 2900, Hellerup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, University of Copenhagen, Gentofte, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette M Rosenkilde
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Filip K Knop
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Kildegårdsvej 28, 2900, Hellerup, Denmark.
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
114
|
Hædersdal S, Lund A, Knop FK, Vilsbøll T. The Role of Glucagon in the Pathophysiology and Treatment of Type 2 Diabetes. Mayo Clin Proc 2018; 93:217-239. [PMID: 29307553 DOI: 10.1016/j.mayocp.2017.12.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 12/04/2017] [Accepted: 12/07/2017] [Indexed: 12/19/2022]
Abstract
Type 2 diabetes is a disease involving both inadequate insulin levels and increased glucagon levels. While glucagon and insulin work together to achieve optimal plasma glucose concentrations in healthy individuals, the usual regulatory balance between these 2 critical pancreatic hormones is awry in patients with diabetes. Although clinical discussion often focuses on the role of insulin, glucagon is equally important in understanding type 2 diabetes. Furthermore, an awareness of the role of glucagon is essential to appreciate differences in the mechanisms of action of various classes of glucose-lowering therapies. Newer drug classes such as dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists improve glycemic control, in part, by affecting glucagon levels. This review provides an overview of the effect of glucose-lowering therapies on glucagon on the basis of an extensive PubMed literature search to identify clinical studies of glucose-lowering therapies in type 2 diabetes that included assessment of glucagon. Clinical practice currently benefits from available therapies that impact the glucagon regulatory pathway. As clinicians look to the future, improved treatment strategies are likely to emerge that will either use currently available therapies whose mechanisms of action complement each other or take advantage of new therapies based on an improved understanding of glucagon pathophysiology.
Collapse
Affiliation(s)
- Sofie Hædersdal
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Asger Lund
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Filip K Knop
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark; Faculty of Health and Medical Sciences, Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tina Vilsbøll
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark; Steno Diabetes Center Copenhagen, University of Copenhagen, Gentofte, Denmark; Faculty of Health and Medical Sciences, Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
115
|
van der Meulen T, Lee S, Noordeloos E, Donaldson CJ, Adams MW, Noguchi GM, Mawla AM, Huising MO. Artemether Does Not Turn α Cells into β Cells. Cell Metab 2018; 27:218-225.e4. [PMID: 29103923 PMCID: PMC5762275 DOI: 10.1016/j.cmet.2017.10.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 08/05/2017] [Accepted: 10/05/2017] [Indexed: 12/27/2022]
Abstract
Pancreatic α cells retain considerable plasticity and can, under the right circumstances, transdifferentiate into functionally mature β cells. In search of a targetable mechanistic basis, a recent paper suggested that the widely used anti-malaria drug artemether suppresses the α cell transcription factor Arx to promote transdifferentiation into β cells. However, key initial experiments in this paper were carried out in islet cell lines, and most subsequent validation experiments implied transdifferentiation without direct demonstration of α to β cell conversion. Indeed, we find no evidence that artemether promotes transdifferentiation of primary α cells into β cells. Moreover, artemether reduces Ins2 expression in primary β cells >100-fold, suppresses glucose uptake, and abrogates β cell calcium responses and insulin secretion in response to glucose. Our observations suggest that artemether induces general islet endocrine cell dedifferentiation and call into question the utility of artemisinins to promote α to β cell transdifferentiation in treating diabetes.
Collapse
Affiliation(s)
- Talitha van der Meulen
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Sharon Lee
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Els Noordeloos
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Cynthia J Donaldson
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Michael W Adams
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Glyn M Noguchi
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Alex M Mawla
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Mark O Huising
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, CA 95616, USA; Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, CA 95616, USA.
| |
Collapse
|
116
|
Hayashi Y, Seino Y. Regulation of amino acid metabolism and α-cell proliferation by glucagon. J Diabetes Investig 2018; 9:464-472. [PMID: 29314731 PMCID: PMC5934249 DOI: 10.1111/jdi.12797] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 12/21/2017] [Indexed: 12/25/2022] Open
Abstract
Both glucagon and glucagon-like peptide-1 (GLP-1) are produced from proglucagon through proteolytic cleavage. Blocking glucagon action increases the circulating levels of glucagon and GLP-1, reduces the blood glucose level, and induces the proliferation of islet α-cells. Glucagon blockade also suppresses hepatic amino acid catabolism and increases the serum amino acid level. In animal models defective in both glucagon and GLP-1, the blood glucose level is not reduced, indicating that GLP-1 is required for glucagon blockade to reduce the blood glucose level. In contrast, hyperplasia of α-cells and hyperaminoacidemia are observed in such animal models, indicating that GLP-1 is not required for the regulation of α-cell proliferation or amino acid metabolism. These findings suggest that the regulation of amino acid metabolism is a more important specific physiological role of glucagon than the regulation of glucose metabolism. Although the effects of glucagon deficiency on glucose metabolism are compensated by the suppression of insulin secretion, the effects on amino acid metabolism are not. Recently, data showing a feedback regulatory mechanism between the liver and islet α-cells, which is mediated by glucagon and amino acids, are accumulating. However, a number of questions on the mechanism of this regulation remain to be addressed. The profile of glucagon as a regulator of amino acid metabolism must be carefully considered for glucagon blockade to be applied therapeutically in the treatment of patients with diabetes.
Collapse
Affiliation(s)
- Yoshitaka Hayashi
- Division of Stress Adaptation and ProtectionResearch Institute of Environmental MedicineNagoyaJapan
| | - Yusuke Seino
- Department of Endocrinology and DiabetesNagoya University Graduate School of MedicineNagoya UniversityNagoyaJapan
| |
Collapse
|
117
|
Wewer Albrechtsen NJ, Junker AE, Christensen M, Hædersdal S, Wibrand F, Lund AM, Galsgaard KD, Holst JJ, Knop FK, Vilsbøll T. Hyperglucagonemia correlates with plasma levels of non-branched-chain amino acids in patients with liver disease independent of type 2 diabetes. Am J Physiol Gastrointest Liver Physiol 2018; 314:G91-G96. [PMID: 28971838 DOI: 10.1152/ajpgi.00216.2017] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Patients with type 2 diabetes (T2D) and patients with nonalcoholic fatty liver disease (NAFLD) frequently exhibit elevated plasma concentrations of glucagon (hyperglucagonemia). Hyperglucagonemia and α-cell hyperplasia may result from elevated levels of plasma amino acids when glucagon's action on hepatic amino acid metabolism is disrupted. We therefore measured plasma levels of glucagon and individual amino acids in patients with and without biopsy-verified NAFLD and with and without type T2D. Fasting levels of amino acids and glucagon in plasma were measured, using validated ELISAs and high-performance liquid chromatography, in obese, middle-aged individuals with I) normal glucose tolerance (NGT) and NAFLD, II) T2D and NAFLD, III) T2D without liver disease, and IV) NGT and no liver disease. Elevated levels of total amino acids were observed in participants with NAFLD and NGT compared with NGT controls (1,310 ± 235 µM vs. 937 ± 281 µM, P = 0.03) and in T2D and NAFLD compared with T2D without liver disease (1,354 ± 329 µM vs. 511 ± 235 µM, P < 0.0001). Particularly amino acids with known glucagonotropic effects (e.g., glutamine) were increased. Plasma levels of total amino acids correlated to plasma levels of glucagon also when adjusting for body mass index (BMI), glycated hemoglobin (HbA1c), and cholesterol levels (β = 0.013 ± 0.007, P = 0.024). Elevated plasma levels of total amino acids associate with hyperglucagonemia in NAFLD patients independently of glycemic control, BMI or cholesterol - supporting the potential importance of a "liver-α-cell axis" in which glucagon regulates hepatic amino acid metabolism. Fasting hyperglucagonemia as seen in T2D may therefore represent impaired hepatic glucagon action with increasing amino acids levels. NEW & NOTEWORTHY Hypersecretion of glucagon (hyperglucagonemia) has been suggested to be linked to type 2 diabetes. Here, we show that levels of amino acids correlate with levels of glucagon. Hyperglucagonemia may depend on hepatic steatosis rather than type 2 diabetes.
Collapse
Affiliation(s)
- Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Anders E Junker
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Mette Christensen
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet , Copenhagen , Denmark
| | - Sofie Hædersdal
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Flemming Wibrand
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet , Copenhagen , Denmark
| | - Allan M Lund
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet , Copenhagen , Denmark
| | - Katrine D Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Filip K Knop
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark.,Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Tina Vilsbøll
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark.,Steno Diabetes Center Copenhagen, University of Copenhagen, Gentofte, Denmark
| |
Collapse
|
118
|
Galsgaard KD, Winther-Sørensen M, Ørskov C, Kissow H, Poulsen SS, Vilstrup H, Prehn C, Adamski J, Jepsen SL, Hartmann B, Hunt J, Charron MJ, Pedersen J, Wewer Albrechtsen NJ, Holst JJ. Disruption of glucagon receptor signaling causes hyperaminoacidemia exposing a possible liver-alpha-cell axis. Am J Physiol Endocrinol Metab 2018; 314:E93-E103. [PMID: 28978545 PMCID: PMC6048389 DOI: 10.1152/ajpendo.00198.2017] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glucagon secreted from the pancreatic alpha-cells is essential for regulation of blood glucose levels. However, glucagon may play an equally important role in the regulation of amino acid metabolism by promoting ureagenesis. We hypothesized that disruption of glucagon receptor signaling would lead to an increased plasma concentration of amino acids, which in a feedback manner stimulates the secretion of glucagon, eventually associated with compensatory proliferation of the pancreatic alpha-cells. To address this, we performed plasma profiling of glucagon receptor knockout ( Gcgr-/-) mice and wild-type (WT) littermates using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics, and tissue biopsies from the pancreas were analyzed for islet hormones and by histology. A principal component analysis of the plasma metabolome from Gcgr-/- and WT littermates indicated amino acids as the primary metabolic component distinguishing the two groups of mice. Apart from their hyperaminoacidemia, Gcgr-/- mice display hyperglucagonemia, increased pancreatic content of glucagon and somatostatin (but not insulin), and alpha-cell hyperplasia and hypertrophy compared with WT littermates. Incubating cultured α-TC1.9 cells with a mixture of amino acids (Vamin 1%) for 30 min and for up to 48 h led to increased glucagon concentrations (~6-fold) in the media and cell proliferation (~2-fold), respectively. In anesthetized mice, a glucagon receptor-specific antagonist (Novo Nordisk 25-2648, 100 mg/kg) reduced amino acid clearance. Our data support the notion that glucagon secretion and hepatic amino acid metabolism are linked in a close feedback loop, which operates independently of normal variations in glucose metabolism.
Collapse
Affiliation(s)
- Katrine D Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Marie Winther-Sørensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Cathrine Ørskov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Hannelouise Kissow
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Steen S Poulsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Hendrik Vilstrup
- Department of Hepato-Gastroenterology, Aarhus University Hospital , Aarhus , Denmark
| | - Cornelia Prehn
- Institute of Experimental Genetics, Genome Analysis Center, Helmholtz Zentrum, German Research Center for Environmental Health, München-Neuerberg, Germany
| | - Jerzy Adamski
- Institute of Experimental Genetics, Genome Analysis Center, Helmholtz Zentrum, German Research Center for Environmental Health, München-Neuerberg, Germany
- Lehrstul für Experimentelle Genetik, Technishe Universität München, Freising- Weihenstephan , Germany
- German Center for Diabetes Research, München-Nueherberg, Germany
| | - Sara L Jepsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Jenna Hunt
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Maureen J Charron
- Departments of Biochemistry, Obstetrics and Gynecology and Women's Health, and Medicine, Albert Einstein College of Medicine , New York, New York
| | - Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| |
Collapse
|
119
|
Thiessen SE, Derde S, Derese I, Dufour T, Vega CA, Langouche L, Goossens C, Peersman N, Vermeersch P, Vander Perre S, Holst JJ, Wouters PJ, Vanhorebeek I, Van den Berghe G. Role of Glucagon in Catabolism and Muscle Wasting of Critical Illness and Modulation by Nutrition. Am J Respir Crit Care Med 2017; 196:1131-1143. [PMID: 28475354 DOI: 10.1164/rccm.201702-0354oc] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
RATIONALE Critical illness is hallmarked by muscle wasting and disturbances in glucose, lipid, and amino acid homeostasis. Circulating concentrations of glucagon, a catabolic hormone that affects these metabolic pathways, are elevated during critical illness. Insight in the nutritional regulation of glucagon and its metabolic role during critical illness is lacking. OBJECTIVES To evaluate whether macronutrient infusion can suppress plasma glucagon during critical illness and study the role of illness-induced glucagon abundance in the disturbed glucose, lipid, and amino acid homeostasis and in muscle wasting during critical illness. METHODS In human and mouse studies, we infused macronutrients and manipulated glucagon availability up and down to investigate its acute and chronic metabolic role during critical illness. MEASUREMENTS AND MAIN RESULTS In critically ill patients, infusing glucose with insulin did not lower glucagon, whereas parenteral nutrition containing amino acids increased glucagon. In critically ill mice, infusion of amino acids increased glucagon and up-regulated markers of hepatic amino acid catabolism without affecting muscle wasting. Immunoneutralizing glucagon in critically ill mice only transiently affected glucose and lipid metabolism, did not affect muscle wasting, but drastically suppressed markers of hepatic amino acid catabolism and reversed the illness-induced hypoaminoacidemia. CONCLUSIONS These data suggest that elevated glucagon availability during critical illness increases hepatic amino acid catabolism, explaining the illness-induced hypoaminoacidemia, without affecting muscle wasting and without a sustained impact on blood glucose. Furthermore, amino acid infusion likely results in a further breakdown of amino acids in the liver, mediated by increased glucagon, without preventing muscle wasting. Clinical trial registered with www.clinicaltrials.gov (NCT 00512122).
Collapse
Affiliation(s)
- Steven E Thiessen
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| | - Sarah Derde
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| | - Inge Derese
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| | - Thomas Dufour
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| | - Chloé Albert Vega
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| | - Lies Langouche
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| | - Chloë Goossens
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| | - Nele Peersman
- 2 Department of Laboratory Medicine, KU Leuven, Leuven, Belgium; and
| | - Pieter Vermeersch
- 2 Department of Laboratory Medicine, KU Leuven, Leuven, Belgium; and
| | - Sarah Vander Perre
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| | - Jens J Holst
- 3 Novo Nordisk Foundation Center for Basic Metabolic Research and.,4 Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Pieter J Wouters
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| | - Ilse Vanhorebeek
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| | - Greet Van den Berghe
- 1 Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
| |
Collapse
|
120
|
Bozadjieva N, Blandino-Rosano M, Chase J, Dai XQ, Cummings K, Gimeno J, Dean D, Powers AC, Gittes GK, Rüegg MA, Hall MN, MacDonald PE, Bernal-Mizrachi E. Loss of mTORC1 signaling alters pancreatic α cell mass and impairs glucagon secretion. J Clin Invest 2017; 127:4379-4393. [PMID: 29106387 DOI: 10.1172/jci90004] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 09/26/2017] [Indexed: 01/19/2023] Open
Abstract
Glucagon plays a major role in the regulation of glucose homeostasis during fed and fasting states. However, the mechanisms responsible for the regulation of pancreatic α cell mass and function are not completely understood. In the current study, we identified mTOR complex 1 (mTORC1) as a major regulator of α cell mass and glucagon secretion. Using mice with tissue-specific deletion of the mTORC1 regulator Raptor in α cells (αRaptorKO), we showed that mTORC1 signaling is dispensable for α cell development, but essential for α cell maturation during the transition from a milk-based diet to a chow-based diet after weaning. Moreover, inhibition of mTORC1 signaling in αRaptorKO mice and in WT animals exposed to chronic rapamycin administration decreased glucagon content and glucagon secretion. In αRaptorKO mice, impaired glucagon secretion occurred in response to different secretagogues and was mediated by alterations in KATP channel subunit expression and activity. Additionally, our data identify the mTORC1/FoxA2 axis as a link between mTORC1 and transcriptional regulation of key genes responsible for α cell function. Thus, our results reveal a potential function of mTORC1 in nutrient-dependent regulation of glucagon secretion and identify a role for mTORC1 in controlling α cell-mass maintenance.
Collapse
Affiliation(s)
- Nadejda Bozadjieva
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, and.,Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Manuel Blandino-Rosano
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, and.,Department of Internal Medicine, Division Endocrinology, Metabolism and Diabetes, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Jennifer Chase
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Xiao-Qing Dai
- Alberta Diabetes Institute and Department of Pharmacology, Edmonton, Alberta, Canada
| | - Kelsey Cummings
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, and
| | - Jennifer Gimeno
- Department of Internal Medicine, Division Endocrinology, Metabolism and Diabetes, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Danielle Dean
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, and
| | - Alvin C Powers
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, and.,Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, Tennessee, USA.,VA Tennessee Valley Healthcare, Nashville, Tennessee, USA
| | - George K Gittes
- Children's Hospital, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | | | | | - Patrick E MacDonald
- Alberta Diabetes Institute and Department of Pharmacology, Edmonton, Alberta, Canada
| | - Ernesto Bernal-Mizrachi
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, and.,Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan, USA.,Department of Internal Medicine, Division Endocrinology, Metabolism and Diabetes, Miller School of Medicine, University of Miami, Miami, Florida, USA.,Veterans Affairs Medical Center, Miami, Florida, USA
| |
Collapse
|
121
|
Kraft G, Coate KC, Winnick JJ, Dardevet D, Donahue EP, Cherrington AD, Williams PE, Moore MC. Glucagon's effect on liver protein metabolism in vivo. Am J Physiol Endocrinol Metab 2017; 313:E263-E272. [PMID: 28536182 PMCID: PMC5625084 DOI: 10.1152/ajpendo.00045.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 05/22/2017] [Accepted: 05/22/2017] [Indexed: 11/22/2022]
Abstract
The postprandial state is characterized by a storage of nutrients in the liver, muscle, and adipose tissue for later utilization. In the case of a protein-rich meal, amino acids (AA) stimulate glucagon secretion by the α-cell. The aim of the present study was to determine the impact of the rise in glucagon on AA metabolism, particularly in the liver. We used a conscious catheterized dog model to recreate a postprandial condition using a pancreatic clamp. Portal infusions of glucose, AA, and insulin were used to achieve postprandial levels, while portal glucagon infusion was either maintained at the basal level or increased by three-fold. The high glucagon infusion reduced the increase in arterial AA concentrations compared with the basal glucagon level (-23%, P < 0.05). In the presence of high glucagon, liver AA metabolism shifted toward a more catabolic state with less protein synthesis (-36%) and increased urea production (+52%). Net hepatic glucose uptake was reduced modestly (-35%), and AA were preferentially used in gluconeogenesis, leading to lower glycogen synthesis (-54%). The phosphorylation of AMPK was increased by the high glucagon infusion (+40%), and this could be responsible for increasing the expression of genes related to pathways producing energy and lowering those involved in energy consumption. In conclusion, the rise in glucagon associated with a protein-rich meal promotes a catabolic utilization of AA in the liver, thereby, opposing the storage of AA in proteins.
Collapse
Affiliation(s)
- Guillaume Kraft
- Department of Molecular Physiology and Biophysics,Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Katie C Coate
- Department of Molecular Physiology and Biophysics,Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Jason J Winnick
- Department of Molecular Physiology and Biophysics,Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Dominique Dardevet
- Université Clermont Auvergne, Institut National de la Recherche Agronomique, Unité de Nutrition Humaine, Clermont-Ferrand, France
| | - E Patrick Donahue
- Department of Molecular Physiology and Biophysics,Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Alan D Cherrington
- Department of Molecular Physiology and Biophysics,Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Phillip E Williams
- Department of Molecular Physiology and Biophysics,Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Mary Courtney Moore
- Department of Molecular Physiology and Biophysics,Vanderbilt University School of Medicine, Nashville, Tennessee; and
| |
Collapse
|
122
|
Kim J, Okamoto H, Huang Z, Anguiano G, Chen S, Liu Q, Cavino K, Xin Y, Na E, Hamid R, Lee J, Zambrowicz B, Unger R, Murphy AJ, Xu Y, Yancopoulos GD, Li WH, Gromada J. Amino Acid Transporter Slc38a5 Controls Glucagon Receptor Inhibition-Induced Pancreatic α Cell Hyperplasia in Mice. Cell Metab 2017; 25:1348-1361.e8. [PMID: 28591637 PMCID: PMC8206958 DOI: 10.1016/j.cmet.2017.05.006] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 03/09/2017] [Accepted: 05/21/2017] [Indexed: 12/22/2022]
Abstract
Glucagon supports glucose homeostasis by stimulating hepatic gluconeogenesis, in part by promoting the uptake and conversion of amino acids into gluconeogenic precursors. Genetic disruption or pharmacologic inhibition of glucagon signaling results in elevated plasma amino acids and compensatory glucagon hypersecretion involving expansion of pancreatic α cell mass. Recent findings indicate that hyperaminoacidemia triggers pancreatic α cell proliferation via an mTOR-dependent pathway. We confirm and extend these findings by demonstrating that glucagon pathway blockade selectively increases expression of the sodium-coupled neutral amino acid transporter Slc38a5 in a subset of highly proliferative α cells and that Slc38a5 controls the pancreatic response to glucagon pathway blockade; most notably, mice deficient in Slc38a5 exhibit markedly decreased α cell hyperplasia to glucagon pathway blockade-induced hyperaminoacidemia. These results show that Slc38a5 is a key component of the feedback circuit between glucagon receptor signaling in the liver and amino-acid-dependent regulation of pancreatic α cell mass in mice.
Collapse
Affiliation(s)
- Jinrang Kim
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - Haruka Okamoto
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - ZhiJiang Huang
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Guillermo Anguiano
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Shiuhwei Chen
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Qing Liu
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Katie Cavino
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - Yurong Xin
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - Erqian Na
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - Rachid Hamid
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | - Joseph Lee
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA
| | | | - Roger Unger
- Touchstone Center for Diabetes Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | | | - Yan Xu
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | | | - Wen-Hong Li
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA.
| | - Jesper Gromada
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY 10591, USA.
| |
Collapse
|
123
|
Dean ED, Li M, Prasad N, Wisniewski SN, Von Deylen A, Spaeth J, Maddison L, Botros A, Sedgeman LR, Bozadjieva N, Ilkayeva O, Coldren A, Poffenberger G, Shostak A, Semich MC, Aamodt KI, Phillips N, Yan H, Bernal-Mizrachi E, Corbin JD, Vickers KC, Levy SE, Dai C, Newgard C, Gu W, Stein R, Chen W, Powers AC. Interrupted Glucagon Signaling Reveals Hepatic α Cell Axis and Role for L-Glutamine in α Cell Proliferation. Cell Metab 2017; 25:1362-1373.e5. [PMID: 28591638 PMCID: PMC5572896 DOI: 10.1016/j.cmet.2017.05.011] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 03/15/2017] [Accepted: 05/23/2017] [Indexed: 02/06/2023]
Abstract
Decreasing glucagon action lowers the blood glucose and may be useful therapeutically for diabetes. However, interrupted glucagon signaling leads to α cell proliferation. To identify postulated hepatic-derived circulating factor(s) responsible for α cell proliferation, we used transcriptomics/proteomics/metabolomics in three models of interrupted glucagon signaling and found that proliferation of mouse, zebrafish, and human α cells was mTOR and FoxP transcription factor dependent. Changes in hepatic amino acid (AA) catabolism gene expression predicted the observed increase in circulating AAs. Mimicking these AA levels stimulated α cell proliferation in a newly developed in vitro assay with L-glutamine being a critical AA. α cell expression of the AA transporter Slc38a5 was markedly increased in mice with interrupted glucagon signaling and played a role in α cell proliferation. These results indicate a hepatic α islet cell axis where glucagon regulates serum AA availability and AAs, especially L-glutamine, regulate α cell proliferation and mass via mTOR-dependent nutrient sensing.
Collapse
Affiliation(s)
- E Danielle Dean
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Mingyu Li
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; School of Pharmaceutical Sciences, Xiamen University, Xiamen 361005, China
| | - Nripesh Prasad
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Scott N Wisniewski
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alison Von Deylen
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Jason Spaeth
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Lisette Maddison
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Anthony Botros
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Leslie R Sedgeman
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Nadejda Bozadjieva
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Health System, Ann Arbor, MI 48103, USA
| | - Olga Ilkayeva
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, NC 27701, USA
| | - Anastasia Coldren
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Greg Poffenberger
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alena Shostak
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Michael C Semich
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Kristie I Aamodt
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Neil Phillips
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Hai Yan
- REMD Biotherapeutics, Camarillo, CA 93012, USA
| | - Ernesto Bernal-Mizrachi
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Miami, Miami, FL 33146, USA
| | - Jackie D Corbin
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Kasey C Vickers
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Shawn E Levy
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Chunhua Dai
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Christopher Newgard
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, NC 27701, USA
| | - Wei Gu
- Amgen, Thousand Oaks, CA 91320, USA
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Wenbiao Chen
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alvin C Powers
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; VA Tennessee Valley Healthcare, Nashville, TN 37212, USA.
| |
Collapse
|
124
|
van der Meulen T, Mawla AM, DiGruccio MR, Adams MW, Nies V, Dólleman S, Liu S, Ackermann AM, Cáceres E, Hunter AE, Kaestner KH, Donaldson CJ, Huising MO. Virgin Beta Cells Persist throughout Life at a Neogenic Niche within Pancreatic Islets. Cell Metab 2017; 25:911-926.e6. [PMID: 28380380 PMCID: PMC8586897 DOI: 10.1016/j.cmet.2017.03.017] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 02/14/2017] [Accepted: 03/21/2017] [Indexed: 12/21/2022]
Abstract
Postnatal maintenance or regeneration of pancreatic beta cells is considered to occur exclusively via the replication of existing beta cells, but clinically meaningful restoration of human beta cell mass by proliferation has never been achieved. We discovered a population of immature beta cells that is present throughout life and forms from non-beta precursors at a specialized micro-environment or "neogenic niche" at the islet periphery. These cells express insulin, but lack other key beta cell markers, and are transcriptionally immature, incapable of sensing glucose, and unable to support calcium influx. They constitute an intermediate stage in the transdifferentiation of alpha cells to cells that are functionally indistinguishable from conventional beta cells. We thus identified a lifelong source of new beta cells at a specialized site within healthy islets. By comparing co-existing immature and mature beta cells within healthy islets, we stand to learn how to mature insulin-expressing cells into functional beta cells.
Collapse
Affiliation(s)
- Talitha van der Meulen
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA
| | - Alex M Mawla
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA
| | - Michael R DiGruccio
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA
| | - Michael W Adams
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Vera Nies
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sophie Dólleman
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Siming Liu
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA
| | - Amanda M Ackermann
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA
| | - Elena Cáceres
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Anna E Hunter
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Cynthia J Donaldson
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Mark O Huising
- Department of Neurobiology, Physiology, and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA; Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, CA 95616, USA.
| |
Collapse
|
125
|
|
126
|
Holst JJ, Wewer Albrechtsen NJ, Pedersen J, Knop FK. Glucagon and Amino Acids Are Linked in a Mutual Feedback Cycle: The Liver-α-Cell Axis. Diabetes 2017; 66:235-240. [PMID: 28108603 DOI: 10.2337/db16-0994] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/31/2016] [Indexed: 11/13/2022]
Abstract
Glucagon is usually viewed as an important counterregulatory hormone in glucose metabolism, with actions opposing those of insulin. Evidence exists that shows glucagon is important for minute-to-minute regulation of postprandial hepatic glucose production, although conditions of glucagon excess or deficiency do not cause changes compatible with this view. In patients with glucagon-producing tumors (glucagonomas), the most conspicuous signs are skin lesions (necrolytic migratory erythema), while in subjects with inactivating mutations of the glucagon receptor, pancreatic swelling may be the first sign; neither condition is necessarily associated with disturbed glucose metabolism. In glucagonoma patients, amino acid turnover and ureagenesis are greatly accelerated, and low plasma amino acid levels are probably at least partly responsible for the necrolytic migratory erythema, which resolves after amino acid administration. In patients with receptor mutations (and in knockout mice), pancreatic swelling is due to α-cell hyperplasia with gross hypersecretion of glucagon, which according to recent groundbreaking research may result from elevated amino acid levels. Additionally, solid evidence indicates that ureagenesis, and thereby amino acid levels, is critically controlled by glucagon. Together, this constitutes a complete endocrine system; feedback regulation involving amino acids regulates α-cell function and secretion, while glucagon, in turn, regulates amino acid turnover.
Collapse
Affiliation(s)
- Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Filip K Knop
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| |
Collapse
|
127
|
Angptl4 does not control hyperglucagonemia or α-cell hyperplasia following glucagon receptor inhibition. Proc Natl Acad Sci U S A 2017; 114:2747-2752. [PMID: 28143927 DOI: 10.1073/pnas.1620989114] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Genetic disruption or pharmacologic inhibition of glucagon signaling effectively lowers blood glucose but results in compensatory glucagon hypersecretion involving expansion of pancreatic α-cell mass. Ben-Zvi et al. recently reported that angiopoietin-like protein 4 (Angptl4) links glucagon receptor inhibition to hyperglucagonemia and α-cell proliferation [Ben-Zvi et al. (2015) Proc Natl Acad Sci USA 112:15498-15503]. Angptl4 is a secreted protein and inhibitor of lipoprotein lipase-mediated plasma triglyceride clearance. We report that Angptl4-/- mice treated with an anti-glucagon receptor monoclonal antibody undergo elevation of plasma glucagon levels and α-cell expansion similar to wild-type mice. Overexpression of Angptl4 in liver of mice caused a 8.6-fold elevation in plasma triglyceride levels, but did not alter plasma glucagon levels or α-cell mass. Furthermore, administration of glucagon receptor-blocking antibody to healthy individuals increased plasma glucagon and amino acid levels, but did not change circulating Angptl4 concentration. These data show that Angptl4 does not link glucagon receptor inhibition to compensatory hyperglucagonemia or expansion of α-cell mass, and that it cannot be given to induce such secretion and growth. The reduction of plasma triglyceride levels in Angptl4-/- mice and increase following Angptl4 overexpression suggest that changes in plasma triglyceride metabolism do not regulate α-cells in the pancreas. Our findings corroborate recent data showing that increased plasma amino acids and their transport into α-cells link glucagon receptor blockage to α-cell hyperplasia.
Collapse
|
128
|
Maddison LA, Chen W. Modeling Pancreatic Endocrine Cell Adaptation and Diabetes in the Zebrafish. Front Endocrinol (Lausanne) 2017; 8:9. [PMID: 28184214 PMCID: PMC5266698 DOI: 10.3389/fendo.2017.00009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/11/2017] [Indexed: 12/13/2022] Open
Abstract
Glucose homeostasis is an important element of energy balance and is conserved in organisms from fruit fly to mammals. Central to the control of circulating glucose levels in vertebrates are the endocrine cells of the pancreas, particularly the insulin-producing β-cells and the glucagon producing α-cells. A feature of α- and β-cells is their plasticity, an ability to adapt, in function and number as a response to physiological and pathophysiological conditions of increased hormone demand. The molecular mechanisms underlying these adaptive responses that maintain glucose homeostasis are incompletely defined. The zebrafish is an attractive model due to the low cost, high fecundity, and amenability to genetic and compound screens, and mechanisms governing the development of the pancreatic endocrine cells are conserved between zebrafish and mammals. Post development, both β- and α-cells of zebrafish display plasticity as in mammals. Here, we summarize the studies of pancreatic endocrine cell adaptation in zebrafish. We further explore the utility of the zebrafish as a model for diabetes, a relevant topic considering the increase in diabetes in the human population.
Collapse
Affiliation(s)
- Lisette A. Maddison
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Wenbiao Chen
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| |
Collapse
|
129
|
Glucagon receptor inhibition normalizes blood glucose in severe insulin-resistant mice. Proc Natl Acad Sci U S A 2017; 114:2753-2758. [PMID: 28115707 DOI: 10.1073/pnas.1621069114] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Inactivating mutations in the insulin receptor results in extreme insulin resistance. The resulting hyperglycemia is very difficult to treat, and patients are at risk for early morbidity and mortality from complications of diabetes. We used the insulin receptor antagonist S961 to induce severe insulin resistance, hyperglycemia, and ketonemia in mice. Using this model, we show that glucagon receptor (GCGR) inhibition with a monoclonal antibody normalized blood glucose and β-hydroxybutyrate levels. Insulin receptor antagonism increased pancreatic β-cell mass threefold. Normalization of blood glucose levels with GCGR-blocking antibody unexpectedly doubled β-cell mass relative to that observed with S961 alone and 5.8-fold over control. GCGR antibody blockage expanded α-cell mass 5.7-fold, and S961 had no additional effects. Collectively, these data show that GCGR antibody inhibition represents a potential therapeutic option for treatment of patients with extreme insulin-resistance syndromes.
Collapse
|
130
|
Larger E, Wewer Albrechtsen NJ, Hansen LH, Gelling RW, Capeau J, Deacon CF, Madsen OD, Yakushiji F, De Meyts P, Holst JJ, Nishimura E. Pancreatic α-cell hyperplasia and hyperglucagonemia due to a glucagon receptor splice mutation. Endocrinol Diabetes Metab Case Rep 2016; 2016:EDM160081. [PMID: 27933176 PMCID: PMC5118975 DOI: 10.1530/edm-16-0081] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/03/2016] [Indexed: 12/12/2022] Open
Abstract
Glucagon stimulates hepatic glucose production by activating specific glucagon receptors in the liver, which in turn increase hepatic glycogenolysis as well as gluconeogenesis and ureagenesis from amino acids. Conversely, glucagon secretion is regulated by concentrations of glucose and amino acids. Disruption of glucagon signaling in rodents results in grossly elevated circulating glucagon levels but no hypoglycemia. Here, we describe a patient carrying a homozygous G to A substitution in the invariant AG dinucleotide found in a 3′ mRNA splice junction of the glucagon receptor gene. Loss of the splice site acceptor consensus sequence results in the deletion of 70 nucleotides encoded by exon 9, which introduces a frame shift and an early termination signal in the receptor mRNA sequence. The mutated receptor neither bound 125I-labeled glucagon nor induced cAMP production upon stimulation with up to 1 µM glucagon. Despite the mutation, the only obvious pathophysiological trait was hyperglucagonemia, hyperaminoacidemia and massive hyperplasia of the pancreatic α-cells assessed by histology. Our case supports the notion of a hepato–pancreatic feedback system, which upon disruption leads to hyperglucagonemia and α-cell hyperplasia, as well as elevated plasma amino acid levels. Together with the glucagon-induced hypoaminoacidemia in glucagonoma patients, our case supports recent suggestions that amino acids may provide the feedback link between the liver and the pancreatic α-cells.
Collapse
Affiliation(s)
- Etienne Larger
- Department of Diabetology , Hôpital Bichat and University Paris Denis Diderot, Paris , France
| | - Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lars H Hansen
- Department of Molecular Signaling , Hagedorn Research Institute, Gentofte , Denmark
| | - Richard W Gelling
- Department of Medicine , Yong Loo Lin School of Medicine, National University of Singapore , Singapore
| | - Jacqueline Capeau
- Inserm UMR_S 938, Centre de Recherche Saint-Antoine, Paris, France; Sorbonne University, UPMC, University of Paris 6, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Carolyn F Deacon
- Department of Biomedical Sciences; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ole D Madsen
- Global Research External Affairs , Novo Nordisk A/S, 2760 Måløv , Denmark
| | - Fumiatsu Yakushiji
- Department of Internal Medicine, Tokyo Metropolitan Bokutoh Hospital, Tokyo, Japan; Department of Education Planning and Development, Faculty of Medicine, Toho University, Tokyo, Japan
| | - Pierre De Meyts
- Global Research External Affairs , Novo Nordisk A/S, 2760 Måløv , Denmark
| | - Jens J Holst
- Department of Biomedical Sciences; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Erica Nishimura
- Metabolic Disease Research , Novo Nordisk A/S, Måløv , Denmark
| |
Collapse
|
131
|
Wewer Albrechtsen NJ, Kuhre RE, Pedersen J, Knop FK, Holst JJ. The biology of glucagon and the consequences of hyperglucagonemia. Biomark Med 2016; 10:1141-1151. [PMID: 27611762 DOI: 10.2217/bmm-2016-0090] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The proglucagon-derived peptide hormone, glucagon, comprises 29 amino acids. Its secretion from the pancreatic α cells is regulated by several factors. Glucagon increases blood glucose levels through gluconeogenesis and glycogenolysis. Elevated plasma concentrations of glucagon, hyperglucagonemia, may contribute to diabetes. However, hyperglucagonemia is also observed in other clinical conditions than diabetes, including nonalcoholic fatty liver disease, glucagon-producing tumors and after gastric bypass surgery. Here, we review the current literature on hyperglucagonemia in disease with a particular focus on diabetes, and finally speculate that the primary physiological importance of glucagon may not reside in glucose homeostasis but in regulation of amino acid metabolism exerted via a hitherto unrecognized hepato-pancreatic feedback loop.
Collapse
Affiliation(s)
- Nicolai J Wewer Albrechtsen
- Department of Biomedical Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health & Medical Sciences, University of Copenhagen, Denmark
| | - Rune E Kuhre
- Department of Biomedical Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health & Medical Sciences, University of Copenhagen, Denmark
| | - Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health & Medical Sciences, University of Copenhagen, Denmark
| | - Filip K Knop
- Department of Biomedical Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health & Medical Sciences, University of Copenhagen, Denmark.,Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health & Medical Sciences, University of Copenhagen, Denmark
| |
Collapse
|
132
|
Rhyu J, Yu R. Mahvash disease: an autosomal recessive hereditary pancreatic neuroendocrine tumor syndrome. INTERNATIONAL JOURNAL OF ENDOCRINE ONCOLOGY 2016. [DOI: 10.2217/ije-2016-0005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Jane Rhyu
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- Division of Endocrinology, Cedars-Sinai Medical Center, Los Angeles, CA, USA; current address Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, CA, USA,
| | - Run Yu
- Division of Endocrinology, Cedars-Sinai Medical Center, Los Angeles, CA, USA; current address Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, CA, USA,
| |
Collapse
|
133
|
Pearson MJ, Unger RH, Holland WL. Clinical Trials, Triumphs, and Tribulations of Glucagon Receptor Antagonists. Diabetes Care 2016; 39:1075-7. [PMID: 27330122 PMCID: PMC5876017 DOI: 10.2337/dci15-0033] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Mackenzie J Pearson
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Roger H Unger
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX VA North Texas Health Care System, Dallas, TX
| | - William L Holland
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| |
Collapse
|
134
|
Lund A, Bagger JI, Wewer Albrechtsen NJ, Christensen M, Grøndahl M, Hartmann B, Mathiesen ER, Hansen CP, Storkholm JH, van Hall G, Rehfeld JF, Hornburg D, Meissner F, Mann M, Larsen S, Holst JJ, Vilsbøll T, Knop FK. Evidence of Extrapancreatic Glucagon Secretion in Man. Diabetes 2016; 65:585-97. [PMID: 26672094 DOI: 10.2337/db15-1541] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/06/2015] [Indexed: 12/27/2022]
Abstract
Glucagon is believed to be a pancreas-specific hormone, and hyperglucagonemia has been shown to contribute significantly to the hyperglycemic state of patients with diabetes. This hyperglucagonemia has been thought to arise from α-cell insensitivity to suppressive effects of glucose and insulin combined with reduced insulin secretion. We hypothesized that postabsorptive hyperglucagonemia represents a gut-dependent phenomenon and subjected 10 totally pancreatectomized patients and 10 healthy control subjects to a 75-g oral glucose tolerance test and a corresponding isoglycemic intravenous glucose infusion. We applied novel analytical methods of plasma glucagon (sandwich ELISA and mass spectrometry-based proteomics) and show that 29-amino acid glucagon circulates in patients without a pancreas and that glucose stimulation of the gastrointestinal tract elicits significant hyperglucagonemia in these patients. These findings emphasize the existence of extrapancreatic glucagon (perhaps originating from the gut) in man and suggest that it may play a role in diabetes secondary to total pancreatectomy.
Collapse
Affiliation(s)
- Asger Lund
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark The Novo Nordisk Foundation Center for Basic Metabolic Research and Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jonatan I Bagger
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark The Novo Nordisk Foundation Center for Basic Metabolic Research and Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicolai J Wewer Albrechtsen
- The Novo Nordisk Foundation Center for Basic Metabolic Research and Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Mikkel Christensen
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark The Novo Nordisk Foundation Center for Basic Metabolic Research and Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Magnus Grøndahl
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Bolette Hartmann
- The Novo Nordisk Foundation Center for Basic Metabolic Research and Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elisabeth R Mathiesen
- Center for Pregnant Women with Diabetes, Department of Endocrinology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Carsten P Hansen
- Department of Gastrointestinal Surgery, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Jan H Storkholm
- Department of Gastrointestinal Surgery, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Gerrit van Hall
- Clinical Metabolomics Core Facility, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Jens F Rehfeld
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Daniel Hornburg
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Felix Meissner
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany The Novo Nordisk Foundation Center for Protein Research, Proteomics Program, University of Copenhagen, Copenhagen, Denmark
| | - Steen Larsen
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Jens J Holst
- The Novo Nordisk Foundation Center for Basic Metabolic Research and Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tina Vilsbøll
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Filip K Knop
- Center for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark The Novo Nordisk Foundation Center for Basic Metabolic Research and Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
135
|
Angptl4 links α-cell proliferation following glucagon receptor inhibition with adipose tissue triglyceride metabolism. Proc Natl Acad Sci U S A 2015; 112:15498-503. [PMID: 26621734 DOI: 10.1073/pnas.1513872112] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Type 2 diabetes is characterized by a reduction in insulin function and an increase in glucagon activity that together result in hyperglycemia. Glucagon receptor antagonists have been developed as drugs for diabetes; however, they often increase glucagon plasma levels and induce the proliferation of glucagon-secreting α-cells. We find that the secreted protein Angiopoietin-like 4 (Angptl4) is up-regulated via Pparγ activation in white adipose tissue and plasma following an acute treatment with a glucagon receptor antagonist. Induction of adipose angptl4 and Angptl4 supplementation promote α-cell proliferation specifically. Finally, glucagon receptor antagonist improves glycemia in diet-induced obese angptl4 knockout mice without increasing glucagon levels or α-cell proliferation, underscoring the importance of this protein. Overall, we demonstrate that triglyceride metabolism in adipose tissue regulates α-cells in the endocrine pancreas.
Collapse
|