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Sun EW, Iepsen EW, Pezos N, Lumsden AL, Martin AM, Schober G, Isaacs NJ, Rayner CK, Nguyen NQ, de Fontgalland D, Rabbitt P, Hollington P, Wattchow DA, Hansen T, Holm JC, Liou AP, Jackson VM, Torekov SS, Young RL, Keating DJ. A Gut-Intrinsic Melanocortin Signaling Complex Augments L-Cell Secretion in Humans. Gastroenterology 2021; 161:536-547.e2. [PMID: 33848536 DOI: 10.1053/j.gastro.2021.04.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 04/04/2021] [Accepted: 04/06/2021] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Hypothalamic melanocortin 4 receptors (MC4R) are a key regulator of energy homeostasis. Brain-penetrant MC4R agonists have failed, as concentrations required to suppress food intake also increase blood pressure. However, peripherally located MC4R may also mediate metabolic benefits of MC4R activation. Mc4r transcript is enriched in mouse enteroendocrine L cells and peripheral administration of the endogenous MC4R agonist, α-melanocyte stimulating hormone (α-MSH), triggers the release of the anorectic hormones Glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) in mice. This study aimed to determine whether pathways linking MC4R and L-cell secretion exist in humans. DESIGN GLP-1 and PYY levels were assessed in body mass index-matched individuals with or without loss-of-function MC4R mutations following an oral glucose tolerance test. Immunohistochemistry was performed on human intestinal sections to characterize the mucosal MC4R system. Static incubations with MC4R agonists were carried out on human intestinal epithelia, GLP-1 and PYY contents of secretion supernatants were assayed. RESULTS Fasting PYY levels and oral glucose-induced GLP-1 secretion were reduced in humans carrying a total loss-of-function MC4R mutation. MC4R was localized to L cells and regulates GLP-1 and PYY secretion from ex vivo human intestine. α-MSH immunoreactivity in the human intestinal epithelia was predominantly localized to L cells. Glucose-sensitive mucosal pro-opiomelanocortin cells provide a local source of α-MSH that is essential for glucose-induced GLP-1 secretion in small intestine. CONCLUSION Our findings describe a previously unidentified signaling nexus in the human gastrointestinal tract involving α-MSH release and MC4R activation on L cells in an autocrine and paracrine fashion. Outcomes from this study have direct implications for targeting mucosal MC4R to treat human metabolic disorders.
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Affiliation(s)
- Emily W Sun
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, Australia
| | - Eva W Iepsen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Nektaria Pezos
- Nutrition, Diabetes and Metabolism, Lifelong Health, South Australia Health and Medical Research Institute, Adelaide, Australia; Adelaide Medical School and NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Australia
| | - Amanda L Lumsden
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, Australia
| | - Alyce M Martin
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, Australia
| | - Gudrun Schober
- Nutrition, Diabetes and Metabolism, Lifelong Health, South Australia Health and Medical Research Institute, Adelaide, Australia; Adelaide Medical School and NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Australia
| | - Nichole J Isaacs
- Nutrition, Diabetes and Metabolism, Lifelong Health, South Australia Health and Medical Research Institute, Adelaide, Australia; Adelaide Medical School and NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Australia
| | - Christopher K Rayner
- Adelaide Medical School and NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Australia; Department of Gastroenterology and Hepatology, Royal Adelaide Hospital, Adelaide, Australia
| | - Nam Q Nguyen
- Adelaide Medical School and NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Australia; Department of Gastroenterology and Hepatology, Royal Adelaide Hospital, Adelaide, Australia
| | | | - Philippa Rabbitt
- Department of Surgery, Flinders Medical Centre, Bedford Park, Australia
| | - Paul Hollington
- Department of Surgery, Flinders Medical Centre, Bedford Park, Australia
| | - David A Wattchow
- Department of Surgery, Flinders Medical Centre, Bedford Park, Australia
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Jens-Christian Holm
- The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark; Department of Pediatrics, Holbæk University Hospital, Holbæk, Denmark
| | - Alice P Liou
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, Massachusetts
| | - V Margaret Jackson
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, Massachusetts
| | - Signe S Torekov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
| | - Richard L Young
- Nutrition, Diabetes and Metabolism, Lifelong Health, South Australia Health and Medical Research Institute, Adelaide, Australia; Adelaide Medical School and NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Australia.
| | - Damien J Keating
- Flinders Health and Medical Research Institute, College of Medicine and Public Health, Flinders University, Bedford Park, Australia.
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2
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Frisbee AL, Saleh MM, Young MK, Leslie JL, Simpson ME, Abhyankar MM, Cowardin CA, Ma JZ, Pramoonjago P, Turner SD, Liou AP, Buonomo EL, Petri WA. IL-33 drives group 2 innate lymphoid cell-mediated protection during Clostridium difficile infection. Nat Commun 2019; 10:2712. [PMID: 31221971 PMCID: PMC6586630 DOI: 10.1038/s41467-019-10733-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/23/2019] [Indexed: 12/19/2022] Open
Abstract
Clostridium difficile (C. difficile) incidence has tripled over the past 15 years and is attributed to the emergence of hypervirulent strains. While it is clear that C. difficile toxins cause damaging colonic inflammation, the immune mechanisms protecting from tissue damage require further investigation. Through a transcriptome analysis, we identify IL-33 as an immune target upregulated in response to hypervirulent C. difficile. We demonstrate that IL-33 prevents C. difficile-associated mortality and epithelial disruption independently of bacterial burden or toxin expression. IL-33 drives colonic group 2 innate lymphoid cell (ILC2) activation during infection and IL-33 activated ILC2s are sufficient to prevent disease. Furthermore, intestinal IL-33 expression is regulated by the microbiota as fecal microbiota transplantation (FMT) rescues antibiotic-associated depletion of IL-33. Lastly, dysregulated IL-33 signaling via the decoy receptor, sST2, predicts C. difficile-associated mortality in human patients. Thus, IL-33 signaling to ILC2s is an important mechanism of defense from C. difficile colitis. Here, Frisbee et al. show that hypervirulent Clostridium difficile induces IL-33 expression in the gut and IL-33 reduces mortality and morbidity via group 2 innate lymphoid cells. Furthermore, serum levels of the soluble IL-33 decoy receptor, sST2, are associated with enhanced disease severity in human C. difficile patients.
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Affiliation(s)
- Alyse L Frisbee
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA, 22908, USA
| | - Mahmoud M Saleh
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA, 22908, USA
| | - Mary K Young
- Department of Medicine, University of Virginia Health System, Charlottesville, VA, 22908, USA
| | - Jhansi L Leslie
- Department of Medicine, University of Virginia Health System, Charlottesville, VA, 22908, USA
| | - Morgan E Simpson
- Department of Pathology, University of Virginia Health System, Charlottesville, VA, 22908, USA
| | - Mayuresh M Abhyankar
- Department of Medicine, University of Virginia Health System, Charlottesville, VA, 22908, USA
| | - Carrie A Cowardin
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA, 22908, USA
| | - Jennie Z Ma
- Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Patcharin Pramoonjago
- Department of Pathology, University of Virginia Health System, Charlottesville, VA, 22908, USA
| | - Stephen D Turner
- Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | | | - Erica L Buonomo
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA, 22908, USA
| | - William A Petri
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA, 22908, USA. .,Department of Medicine, University of Virginia Health System, Charlottesville, VA, 22908, USA. .,Department of Pathology, University of Virginia Health System, Charlottesville, VA, 22908, USA.
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3
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Patel S, Alvarez-Guaita A, Melvin A, Rimmington D, Dattilo A, Miedzybrodzka EL, Cimino I, Maurin AC, Roberts GP, Meek CL, Virtue S, Sparks LM, Parsons SA, Redman LM, Bray GA, Liou AP, Woods RM, Parry SA, Jeppesen PB, Kolnes AJ, Harding HP, Ron D, Vidal-Puig A, Reimann F, Gribble FM, Hulston CJ, Farooqi IS, Fafournoux P, Smith SR, Jensen J, Breen D, Wu Z, Zhang BB, Coll AP, Savage DB, O'Rahilly S. GDF15 Provides an Endocrine Signal of Nutritional Stress in Mice and Humans. Cell Metab 2019; 29:707-718.e8. [PMID: 30639358 PMCID: PMC6408327 DOI: 10.1016/j.cmet.2018.12.016] [Citation(s) in RCA: 244] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/10/2018] [Accepted: 12/17/2018] [Indexed: 01/07/2023]
Abstract
GDF15 is an established biomarker of cellular stress. The fact that it signals via a specific hindbrain receptor, GFRAL, and that mice lacking GDF15 manifest diet-induced obesity suggest that GDF15 may play a physiological role in energy balance. We performed experiments in humans, mice, and cells to determine if and how nutritional perturbations modify GDF15 expression. Circulating GDF15 levels manifest very modest changes in response to moderate caloric surpluses or deficits in mice or humans, differentiating it from classical intestinally derived satiety hormones and leptin. However, GDF15 levels do increase following sustained high-fat feeding or dietary amino acid imbalance in mice. We demonstrate that GDF15 expression is regulated by the integrated stress response and is induced in selected tissues in mice in these settings. Finally, we show that pharmacological GDF15 administration to mice can trigger conditioned taste aversion, suggesting that GDF15 may induce an aversive response to nutritional stress.
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Affiliation(s)
- Satish Patel
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Anna Alvarez-Guaita
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Audrey Melvin
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Debra Rimmington
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Alessia Dattilo
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Emily L Miedzybrodzka
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Irene Cimino
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Anne-Catherine Maurin
- INRA, Unité de Nutrition Humaine, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Geoffrey P Roberts
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Claire L Meek
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Samuel Virtue
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Lauren M Sparks
- Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Orlando, FL, USA
| | - Stephanie A Parsons
- Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Orlando, FL, USA
| | | | - George A Bray
- Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Alice P Liou
- Internal Medicine Research Unit, Pfizer Global R&D, 1 Portland Street, Cambridge, MA, USA
| | - Rachel M Woods
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK
| | - Sion A Parry
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK
| | - Per B Jeppesen
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus University, Aarhus, Denmark
| | - Anders J Kolnes
- Section of Specialized Endocrinology, Department of Endocrinology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Heather P Harding
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK; Cambridge Institute for Medical Research, Cambridge University, Cambridge CB2 0XY, UK
| | - David Ron
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK; Cambridge Institute for Medical Research, Cambridge University, Cambridge CB2 0XY, UK
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Frank Reimann
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Fiona M Gribble
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Carl J Hulston
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK
| | - I Sadaf Farooqi
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Pierre Fafournoux
- INRA, Unité de Nutrition Humaine, Université Clermont Auvergne, 63000 Clermont-Ferrand, France
| | - Steven R Smith
- Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Orlando, FL, USA
| | - Jorgen Jensen
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Danna Breen
- Internal Medicine Research Unit, Pfizer Global R&D, 1 Portland Street, Cambridge, MA, USA
| | - Zhidan Wu
- Internal Medicine Research Unit, Pfizer Global R&D, 1 Portland Street, Cambridge, MA, USA
| | - Bei B Zhang
- Internal Medicine Research Unit, Pfizer Global R&D, 1 Portland Street, Cambridge, MA, USA
| | - Anthony P Coll
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - David B Savage
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK.
| | - Stephen O'Rahilly
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK.
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4
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Bahne E, Sun EWL, Young RL, Hansen M, Sonne DP, Hansen JS, Rohde U, Liou AP, Jackson ML, de Fontgalland D, Rabbitt P, Hollington P, Sposato L, Due S, Wattchow DA, Rehfeld JF, Holst JJ, Keating DJ, Vilsbøll T, Knop FK. Metformin-induced glucagon-like peptide-1 secretion contributes to the actions of metformin in type 2 diabetes. JCI Insight 2018; 3:93936. [PMID: 30518693 DOI: 10.1172/jci.insight.93936] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 10/24/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Metformin reduces plasma glucose and has been shown to increase glucagon-like peptide 1 (GLP-1) secretion. Whether this is a direct action of metformin on GLP-1 release, and whether some of the glucose-lowering effect of metformin occurs due to GLP-1 release, is unknown. The current study investigated metformin-induced GLP-1 secretion and its contribution to the overall glucose-lowering effect of metformin and underlying mechanisms in patients with type 2 diabetes. METHODS Twelve patients with type 2 diabetes were included in this placebo-controlled, double-blinded study. On 4 separate days, the patients received metformin (1,500 mg) or placebo suspended in a liquid meal, with subsequent i.v. infusion of the GLP-1 receptor antagonist exendin9-39 (Ex9-39) or saline. During 240 minutes, blood was sampled. The direct effect of metformin on GLP-1 secretion was tested ex vivo in human ileal and colonic tissue with and without dorsomorphin-induced inhibiting of the AMPK activity. RESULTS Metformin increased postprandial GLP-1 secretion compared with placebo (P = 0.014), and the postprandial glucose excursions were significantly smaller after metformin + saline compared with metformin + Ex9-39 (P = 0.004). Ex vivo metformin acutely increased GLP-1 secretion (colonic tissue, P < 0.01; ileal tissue, P < 0.05), but the effect was abolished by inhibition of AMPK activity. CONCLUSIONS Metformin has a direct and AMPK-dependent effect on GLP-1-secreting L cells and increases postprandial GLP-1 secretion, which seems to contribute to metformin's glucose-lowering effect and mode of action. TRIAL REGISTRATION NCT02050074 (https://clinicaltrials.gov/ct2/show/NCT02050074). FUNDING This study received grants from the A.P. Møller Foundation, the Novo Nordisk Foundation, the Danish Medical Association research grant, the Australian Research Council, the National Health and Medical Research Council, and Pfizer Inc.
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Affiliation(s)
- Emilie Bahne
- Clinical Metabolic Physiology, Steno Diabetes Center Copenhagen, Gentofte Hospital, Hellerup, Denmark
| | - Emily W L Sun
- Discipline of Human Physiology and Centre for Neuroscience, Flinders University of South Australia, Adelaide, Australia
| | - Richard L Young
- Adelaide Medical School, University of Adelaide, Adelaide, Australia.,Nutrition and Metabolism, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Morten Hansen
- Clinical Metabolic Physiology, Steno Diabetes Center Copenhagen, Gentofte Hospital, Hellerup, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University Copenhagen, Copenhagen, Denmark
| | - David P Sonne
- Clinical Metabolic Physiology, Steno Diabetes Center Copenhagen, Gentofte Hospital, Hellerup, Denmark.,Department of Clinical Pharmacology, Frederiksberg and Bispebjerg Hospital, University of Copenhagen, Denmark
| | - Jakob S Hansen
- Clinical Metabolic Physiology, Steno Diabetes Center Copenhagen, Gentofte Hospital, Hellerup, Denmark
| | - Ulrich Rohde
- Clinical Metabolic Physiology, Steno Diabetes Center Copenhagen, Gentofte Hospital, Hellerup, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University Copenhagen, Copenhagen, Denmark
| | - Alice P Liou
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, Massachusetts, USA
| | - Margaret L Jackson
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, Massachusetts, USA
| | - Dayan de Fontgalland
- Discipline of Surgery, Flinders University, Adelaide, South Australia, Australia
| | - Philippa Rabbitt
- Discipline of Surgery, Flinders University, Adelaide, South Australia, Australia
| | - Paul Hollington
- Discipline of Surgery, Flinders University, Adelaide, South Australia, Australia
| | - Luigi Sposato
- Discipline of Surgery, Flinders University, Adelaide, South Australia, Australia
| | - Steven Due
- Discipline of Surgery, Flinders University, Adelaide, South Australia, Australia
| | - David A Wattchow
- Discipline of Surgery, Flinders University, Adelaide, South Australia, Australia
| | - Jens F Rehfeld
- Department of Clinical Biochemistry, Rigshospitalet, University Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University Copenhagen, Copenhagen, Denmark
| | - Damien J Keating
- Discipline of Human Physiology and Centre for Neuroscience, Flinders University of South Australia, Adelaide, Australia.,Nutrition and Metabolism, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Tina Vilsbøll
- Clinical Metabolic Physiology, Steno Diabetes Center Copenhagen, Gentofte Hospital, Hellerup, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University Copenhagen, Copenhagen, Denmark
| | - Filip K Knop
- Clinical Metabolic Physiology, Steno Diabetes Center Copenhagen, Gentofte Hospital, Hellerup, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University Copenhagen, Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University Copenhagen, Copenhagen, Denmark
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5
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Young RL, Lumsden AL, Martin AM, Schober G, Pezos N, Thazhath SS, Isaacs NJ, Cvijanovic N, Sun EWL, Wu T, Rayner CK, Nguyen NQ, Fontgalland DD, Rabbitt P, Hollington P, Sposato L, Due SL, Wattchow DA, Liou AP, Jackson VM, Keating DJ. Augmented capacity for peripheral serotonin release in human obesity. Int J Obes (Lond) 2018; 42:1880-1889. [PMID: 29568107 DOI: 10.1038/s41366-018-0047-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 01/08/2018] [Accepted: 01/16/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND/OBJECTIVES Evidence from animal studies highlights an important role for serotonin (5-HT), derived from gut enterochromaffin (EC) cells, in regulating hepatic glucose production, lipolysis and thermogenesis, and promoting obesity and dysglycemia. Evidence in humans is limited, although elevated plasma 5-HT concentrations are linked to obesity. SUBJECTS/METHODS We assessed (i) plasma 5-HT concentrations before and during intraduodenal glucose infusion (4 kcal/min for 30 min) in non-diabetic obese (BMI 44 ± 4 kg/m2, N = 14) and control (BMI 24 ± 1 kg/m2, N = 10) subjects, (ii) functional activation of duodenal EC cells (immunodetection of phospho-extracellular related-kinase, pERK) in response to glucose, and in separate subjects, (iii) expression of tryptophan hydroxylase-1 (TPH1) in duodenum and colon (N = 39), and (iv) 5-HT content in primary EC cells from these regions (N = 85). RESULTS Plasma 5-HT was twofold higher in obese than control responders prior to (P = 0.025), and during (iAUC, P = 0.009), intraduodenal glucose infusion, and related positively to BMI (R2 = 0.334, P = 0.003) and HbA1c (R2 = 0.508, P = 0.009). The density of EC cells in the duodenum was twofold higher at baseline in obese subjects than controls (P = 0.023), with twofold more EC cells activated by glucose infusion in the obese (EC cells co-expressing 5-HT and pERK, P = 0.001), while the 5-HT content of EC cells in duodenum and colon was similar; TPH1 expression was 1.4-fold higher in the duodenum of obese subjects (P = 0.044), and related positively to BMI (R2 = 0.310, P = 0.031). CONCLUSIONS Human obesity is characterized by an increased capacity to produce and release 5-HT from the proximal small intestine, which is strongly linked to higher body mass, and glycemic control. Gut-derived 5-HT is likely to be an important driver of pathogenesis in human obesity and dysglycemia.
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Affiliation(s)
- Richard L Young
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.,Nutrition & Metabolism, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, 5000, Australia
| | - Amanda L Lumsden
- Centre for Neuroscience & Department of Human Physiology, Flinders University, Bedford Park, SA, 5042, Australia
| | - Alyce M Martin
- Centre for Neuroscience & Department of Human Physiology, Flinders University, Bedford Park, SA, 5042, Australia
| | - Gudrun Schober
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.,Nutrition & Metabolism, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, 5000, Australia
| | - Nektaria Pezos
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.,Nutrition & Metabolism, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, 5000, Australia
| | - Sony S Thazhath
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.,NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Nicole J Isaacs
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.,Nutrition & Metabolism, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, 5000, Australia
| | - Nada Cvijanovic
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.,Nutrition & Metabolism, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, 5000, Australia
| | - Emily W L Sun
- Centre for Neuroscience & Department of Human Physiology, Flinders University, Bedford Park, SA, 5042, Australia
| | - Tongzhi Wu
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.,NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Christopher K Rayner
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.,NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Nam Q Nguyen
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.,NHMRC Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Dayan de Fontgalland
- Department of Surgery, Flinders Medical Centre, Bedford Park, SA, 5042, Australia
| | - Philippa Rabbitt
- Department of Surgery, Flinders Medical Centre, Bedford Park, SA, 5042, Australia
| | - Paul Hollington
- Department of Surgery, Flinders Medical Centre, Bedford Park, SA, 5042, Australia
| | - Luigi Sposato
- Department of Surgery, Flinders Medical Centre, Bedford Park, SA, 5042, Australia
| | - Steven L Due
- Department of Surgery, Flinders Medical Centre, Bedford Park, SA, 5042, Australia
| | - David A Wattchow
- Department of Surgery, Flinders Medical Centre, Bedford Park, SA, 5042, Australia
| | - Alice P Liou
- Cardiovascular, Metabolic, and Endocrine Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 02139, USA
| | - V Margaret Jackson
- Cardiovascular, Metabolic, and Endocrine Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, 02139, USA
| | - Damien J Keating
- Nutrition & Metabolism, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, 5000, Australia. .,Centre for Neuroscience & Department of Human Physiology, Flinders University, Bedford Park, SA, 5042, Australia.
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6
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Liou AP, Paziuk M, Luevano JM, Machineni S, Turnbaugh PJ, Kaplan LM. Conserved shifts in the gut microbiota due to gastric bypass reduce host weight and adiposity. Sci Transl Med 2013; 5:178ra41. [PMID: 23536013 DOI: 10.1126/scitranslmed.3005687] [Citation(s) in RCA: 671] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Roux-en-Y gastric bypass (RYGB) results in rapid weight loss, reduced adiposity, and improved glucose metabolism. These effects are not simply attributable to decreased caloric intake or absorption, but the mechanisms linking rearrangement of the gastrointestinal tract to these metabolic outcomes are largely unknown. Studies in humans and rats have shown that RYGB restructures the gut microbiota, prompting the hypothesis that some of the effects of RYGB are caused by altered host-microbial interactions. To test this hypothesis, we used a mouse model of RYGB that recapitulates many of the metabolic outcomes in humans. 16S ribosomal RNA gene sequencing of murine fecal samples collected after RYGB surgery, sham surgery, or sham surgery coupled to caloric restriction revealed that alterations to the gut microbiota after RYGB are conserved among humans, rats, and mice, resulting in a rapid and sustained increase in the relative abundance of Gammaproteobacteria (Escherichia) and Verrucomicrobia (Akkermansia). These changes were independent of weight change and caloric restriction, were detectable throughout the length of the gastrointestinal tract, and were most evident in the distal gut, downstream of the surgical manipulation site. Transfer of the gut microbiota from RYGB-treated mice to nonoperated, germ-free mice resulted in weight loss and decreased fat mass in the recipient animals relative to recipients of microbiota induced by sham surgery, potentially due to altered microbial production of short-chain fatty acids. These findings provide the first empirical support for the claim that changes in the gut microbiota contribute to reduced host weight and adiposity after RYGB surgery.
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Affiliation(s)
- Alice P Liou
- Obesity, Metabolism & Nutrition Institute and Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA 02114, USA
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Lu X, Zhao X, Feng J, Liou AP, Anthony S, Pechhold S, Sun Y, Lu H, Wank S. Postprandial inhibition of gastric ghrelin secretion by long-chain fatty acid through GPR120 in isolated gastric ghrelin cells and mice. Am J Physiol Gastrointest Liver Physiol 2012; 303:G367-76. [PMID: 22678998 PMCID: PMC3774249 DOI: 10.1152/ajpgi.00541.2011] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Ghrelin is a gastric peptide hormone that controls appetite and energy homeostasis. Plasma ghrelin levels rise before a meal and fall quickly thereafter. Elucidation of the regulation of ghrelin secretion has been hampered by the difficulty of directly interrogating ghrelin cells diffusely scattered within the complex gastric mucosa. Therefore, we generated transgenic mice with ghrelin cell expression of green fluorescent protein (GFP) to enable characterization of ghrelin secretion in a pure population of isolated gastric ghrelin-expressing GFP (Ghr-GFP) cells. Using quantitative RT-PCR and immunofluorescence staining, we detected a high level of expression of the long-chain fatty acid (LCFA) receptor GPR120, while the other LCFA receptor, GPR40, was undetectable. In short-term-cultured pure Ghr-GFP cells, the LCFAs docosadienoic acid, linolenic acid, and palmitoleic acid significantly suppressed ghrelin secretion. The physiological mechanism of LCFA inhibition on ghrelin secretion was studied in mice. Serum ghrelin levels were transiently suppressed after gastric gavage of LCFA-rich lipid in mice with pylorus ligation, indicating that the ghrelin cell may directly sense increased gastric LCFA derived from ingested intraluminal lipids. Meal-induced increase in gastric mucosal LCFA was assessed by measuring the transcripts of markers for tissue uptake of LCFA, lipoprotein lipase (LPL), fatty acid translocase (CD36), glycosylphosphatidylinositol-anchored HDL-binding protein 1, and nuclear fatty acid receptor peroxisome proliferator-activated receptor-γ. Quantitative RT-PCR studies indicate significantly increased mRNA levels of lipoprotein lipase, glycosylphosphatidylinositol-anchored HDL-binding protein 1, and peroxisome proliferator-activated receptor-γ in postprandial gastric mucosa. These results suggest that meal-related increases in gastric mucosal LCFA interact with GPR120 on ghrelin cells to inhibit ghrelin secretion.
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Affiliation(s)
- Xinping Lu
- 1Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Xilin Zhao
- 1Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Jianying Feng
- 1Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Alice P. Liou
- 1Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Shari Anthony
- 1Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Susanne Pechhold
- 2Diabetes Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Yuxiang Sun
- 3Children's Nutrition Research Center, Huffington Center on Aging, Departments of Pediatrics and Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas; and
| | - Huiyan Lu
- 4Transgenic Facility, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Stephen Wank
- 1Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
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Liou AP, Chavez DI, Espero E, Hao S, Wank SA, Raybould HE. Protein hydrolysate-induced cholecystokinin secretion from enteroendocrine cells is indirectly mediated by the intestinal oligopeptide transporter PepT1. Am J Physiol Gastrointest Liver Physiol 2011; 300:G895-902. [PMID: 21311026 PMCID: PMC3094145 DOI: 10.1152/ajpgi.00521.2010] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Dietary protein is a major stimulant for cholecystokinin (CCK) secretion by the intestinal I cell, however, the mechanism by which protein is detected is unknown. Indirect functional evidence suggests that PepT1 may play a role in CCK-mediated changes in gastric motor function. However, it is unclear whether this oligopeptide transporter directly or indirectly activates the I cell. Using both the CCK-expressing enteroendocrine STC-1 cell and acutely isolated native I cells from CCK-enhanced green fluorescent protein (eGFP) mice, we aimed to determine whether PepT1 directly activates the enteroendocrine cell to elicit CCK secretion in response to oligopeptides. Both STC-1 cells and isolated CCK-eGFP cells expressed PepT1 transcripts. STC-1 cells were activated, as measured by ERK(1/2) phosphorylation, by both peptone and the PepT1 substrate Cefaclor; however, the PepT1 inhibitor 4-aminomethyl benzoic acid (AMBA) had no effect on STC-1 cell activity. The PepT1-transportable substrate glycyl-sarcosine dose-dependently decreased gastric motility in anesthetized rats but had no affect on activation of STC-1 cells or on CCK secretion by CCK-eGFP cells. CCK secretion was significantly increased in response to peptone but not to Cefaclor, cephalexin, or Phe-Ala in CCK-eGFP cells. Taken together, the data suggest that PepT1 does not directly mediate CCK secretion in response to PepT1 specific substrates. PepT1, instead, may have an indirect role in protein sensing in the intestine.
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Affiliation(s)
- Alice P. Liou
- 1Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, California; and ,2Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Diana I. Chavez
- 1Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, California; and
| | - Elvis Espero
- 1Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, California; and
| | - Shuzhen Hao
- 1Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, California; and
| | - Stephen A. Wank
- 2Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Helen E. Raybould
- 1Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, California; and
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Liou AP, Sei Y, Zhao X, Feng J, Lu X, Thomas C, Pechhold S, Raybould HE, Wank SA. The extracellular calcium-sensing receptor is required for cholecystokinin secretion in response to L-phenylalanine in acutely isolated intestinal I cells. Am J Physiol Gastrointest Liver Physiol 2011; 300:G538-46. [PMID: 21252045 PMCID: PMC3074990 DOI: 10.1152/ajpgi.00342.2010] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The extracellular calcium-sensing receptor (CaSR) has recently been recognized as an L-amino acid sensor and has been implicated in mediating cholecystokinin (CCK) secretion in response to aromatic amino acids. We investigated whether direct detection of L-phenylalanine (L-Phe) by CaSR results in CCK secretion in the native I cell. Fluorescence-activated cell sorting of duodenal I cells from CCK-enhanced green fluorescent protein (eGFP) transgenic mice demonstrated CaSR gene expression. Immunostaining of fixed and fresh duodenal tissue sections confirmed CaSR protein expression. Intracellular calcium fluxes were CaSR dependent, stereoselective for L-Phe over D-Phe, and responsive to type II calcimimetic cinacalcet in CCK-eGFP cells. Additionally, CCK secretion by an isolated I cell population was increased by 30 and 62% in response to L-Phe in the presence of physiological (1.26 mM) and superphysiological (2.5 mM) extracellular calcium concentrations, respectively. While the deletion of CaSR from CCK-eGFP cells did not affect basal CCK secretion, the effect of L-Phe or cinacalcet on intracellular calcium flux was lost. In fact, both secretagogues, as well as superphysiological Ca(2+), evoked an unexpected 20-30% decrease in CCK secretion compared with basal secretion in CaSR(-/-) CCK-eGFP cells. CCK secretion in response to KCl or tryptone was unaffected by the absence of CaSR. The present data suggest that CaSR is required for hormone secretion in the specific response to L-Phe by the native I cell, and that a receptor-mediated mechanism may inhibit hormone secretion in the absence of a fully functional CaSR.
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Affiliation(s)
- Alice P. Liou
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; ,2School of Veterinary Medicine, Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, Davis, California; and
| | - Yoshitatsu Sei
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Xilin Zhao
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Jianying Feng
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Xinping Lu
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
| | - Craig Thomas
- 3Chemical Genomics Center, National Human Genome Research Institute, and
| | - Susanne Pechhold
- 4Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Helen E. Raybould
- 2School of Veterinary Medicine, Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, Davis, California; and
| | - Stephen A. Wank
- 1Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
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Abstract
Intestinal infusion of protein digests activates a vago-vagal reflex inhibition of gastric motility. Protein digests release cholecystokinin (CCK) from enteroendocrine cells; however, the precise cellular mechanisms leading to vagal afferent activation is unclear. The hypothesis that the oligopeptide transporter PepT1 plays a major role in the initiation of this vago-vagal reflex was tested by recording activation of duodenal vagal afferent activity and inhibition of gastric motility in response to protein hydrolysates in the presence of 4-aminomethylbenzoic acid (4-AMBA), a competitive inhibitor of PepT1, or 4-aminophenylacetic acid (4-APAA), an inactive 4-AMBA analog. Duodenal infusion of the protein hydrolysate increased vagal afferent discharge and inhibited gastric motility; these responses were abolished by concomitant infusion of 4-AMBA, but not 4-APAA. Duodenal infusion with Cefaclor, a substrate of PepT1, increased duodenal vagal afferent activity; Cefaclor and protein hydrolysates selectively activated CCK-responsive vagal afferents. This study demonstrates that products of protein digestion increase spontaneous activity of CCK-sensitive duodenal vagal afferents via a mechanism involving the oligopeptide transporter PepT1.
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Affiliation(s)
- N P Darcel
- Department of Anatomy, Physiology and Cell Biology, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA
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