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Verbeek J, Lannoo M, Pirinen E, Ryu D, Spincemaille P, Vander Elst I, Windmolders P, Thevissen K, Cammue BPA, van Pelt J, Fransis S, Van Eyken P, Ceuterick-De Groote C, Van Veldhoven PP, Bedossa P, Nevens F, Auwerx J, Cassiman D. Roux-en-y gastric bypass attenuates hepatic mitochondrial dysfunction in mice with non-alcoholic steatohepatitis. Gut 2015; 64:673-83. [PMID: 24917551 DOI: 10.1136/gutjnl-2014-306748] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [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: 12/19/2022]
Abstract
OBJECTIVE No therapy for non-alcoholic steatohepatitis (NASH) has been approved so far. Roux-en-y gastric bypass (RYGB) is emerging as a therapeutic option, although its effect on NASH and related hepatic molecular pathways is unclear from human studies. We studied the effect of RYGB on pre-existent NASH and hepatic mitochondrial dysfunction-a key player in NASH pathogenesis-in a novel diet-induced mouse model nicely mimicking human disease. DESIGN C57BL/6J mice were fed a high-fat high-sucrose diet (HF-HSD). RESULTS HF-HSD led to early obesity, insulin resistance and hypercholesterolaemia. HF-HSD consistently induced NASH (steatosis, hepatocyte ballooning and inflammation) with fibrosis already after 12-week feeding. NASH was accompanied by hepatic mitochondrial dysfunction, characterised by decreased mitochondrial respiratory chain (MRC) complex I and IV activity, ATP depletion, ultrastructural abnormalities, together with higher 4-hydroxynonenal (HNE) levels, increased uncoupling protein 2 (UCP2) and tumour necrosis factor-α (TNF-α) mRNA and free cholesterol accumulation. In our model of NASH and acquired mitochondrial dysfunction, RYGB induced sustained weight loss, improved insulin resistance and inhibited progression of NASH, with a marked reversal of fibrosis. In parallel, RYGB preserved hepatic MRC complex I activity, restored ATP levels, limited HNE production and decreased TNF-α mRNA. CONCLUSIONS Progression of NASH and NASH-related hepatic mitochondrial dysfunction can be prevented by RYGB. RYGB preserves respiratory chain complex activity, thereby restoring energy output, probably by limiting the amount of oxidative stress and TNF-α. These data suggest that modulation of hepatic mitochondrial function contributes to the favourable effect of RYBG on established NASH.
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Affiliation(s)
- Jef Verbeek
- Department of Hepatology, University Hospitals KU Leuven, Leuven, Belgium
| | - Matthias Lannoo
- Department of Abdominal Surgery, University Hospitals KU Leuven, Leuven, Belgium
| | - Eija Pirinen
- Laboratory for Integrative and Systems Physiology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Departments of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, Biocenter Kuopio, University of Eastern Finland, Kuopio, Finland
| | - Dongryeol Ryu
- Laboratory for Integrative and Systems Physiology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | | | - Ingrid Vander Elst
- Department of Hepatology, University Hospitals KU Leuven, Leuven, Belgium
| | - Petra Windmolders
- Department of Hepatology, University Hospitals KU Leuven, Leuven, Belgium
| | - Karin Thevissen
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium
| | - Bruno P A Cammue
- Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie (VIB), Ghent, Belgium
| | - Jos van Pelt
- Department of Hepatology, University Hospitals KU Leuven, Leuven, Belgium
| | - Sabine Fransis
- Department of Pathology, Ziekenhuis Oost-Limburg, Genk, Belgium
| | - Peter Van Eyken
- Department of Pathology, Ziekenhuis Oost-Limburg, Genk, Belgium
| | - Chantal Ceuterick-De Groote
- Laboratory of Ultrastructural Neuropathology, Institute Born-Bunge (IBB), University of Antwerp, Antwerp, Belgium
| | - Paul P Van Veldhoven
- Laboratory of Lipid Biochemistry and Protein Interactions, KU Leuven, Leuven, Belgium
| | - Pierre Bedossa
- Department of Pathology, Hopital Beaujon, Clichy, France
| | - Frederik Nevens
- Department of Hepatology, University Hospitals KU Leuven, Leuven, Belgium
| | - Johan Auwerx
- Laboratory for Integrative and Systems Physiology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - David Cassiman
- Department of Hepatology, University Hospitals KU Leuven, Leuven, Belgium Metabolic Center, University Hospitals KU Leuven, Leuven, Belgium
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Sonnweber T, Nachbaur D, Schroll A, Nairz M, Seifert M, Demetz E, Haschka D, Mitterstiller AM, Kleinsasser A, Burtscher M, Trübsbach S, Murphy AT, Wroblewski V, Witcher DR, Mleczko-Sanecka K, Vecchi C, Muckenthaler MU, Pietrangelo A, Theurl I, Weiss G. Hypoxia induced downregulation of hepcidin is mediated by platelet derived growth factor BB. Gut 2014; 63:1951-9. [PMID: 24598129 DOI: 10.1136/gutjnl-2013-305317] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [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: 12/11/2022]
Abstract
OBJECTIVE Hypoxia affects body iron homeostasis; however, the underlying mechanisms are incompletely understood. DESIGN Using a standardised hypoxia chamber, 23 healthy volunteers were subjected to hypoxic conditions, equivalent to an altitude of 5600 m, for 6 h. Subsequent experiments were performed in C57BL/6 mice, CREB-H knockout mice, primary hepatocytes and HepG2 cells. RESULTS Exposure of subjects to hypoxia resulted in a significant decrease of serum levels of the master regulator of iron homeostasis hepcidin and elevated concentrations of platelet derived growth factor (PDGF)-BB. Using correlation analysis, we identified PDGF-BB to be associated with hypoxia mediated hepcidin repression in humans. We then exposed mice to hypoxia using a standardised chamber and observed downregulation of hepatic hepcidin mRNA expression that was paralleled by elevated serum PDGF-BB protein concentrations and higher serum iron levels as compared with mice housed under normoxic conditions. PDGF-BB treatment in vitro and in vivo resulted in suppression of both steady state and BMP6 inducible hepcidin expression. Mechanistically, PDGF-BB inhibits hepcidin transcription by downregulating the protein expression of the transcription factors CREB and CREB-H, and pharmacological blockade or genetic ablation of these pathways abrogated the effects of PDGF-BB toward hepcidin expression. CONCLUSIONS Hypoxia decreases hepatic hepcidin expression by a novel regulatory pathway exerted via PDGF-BB, leading to increased availability of circulating iron that can be used for erythropoiesis.
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Affiliation(s)
- Thomas Sonnweber
- Department of Internal Medicine VI, Medical University Innsbruck, Innsbruck, Austria
| | - David Nachbaur
- Department of Internal Medicine V, Medical University Innsbruck, Innsbruck, Austria
| | - Andrea Schroll
- Department of Internal Medicine VI, Medical University Innsbruck, Innsbruck, Austria
| | - Manfred Nairz
- Department of Internal Medicine VI, Medical University Innsbruck, Innsbruck, Austria
| | - Markus Seifert
- Department of Internal Medicine VI, Medical University Innsbruck, Innsbruck, Austria
| | - Egon Demetz
- Department of Internal Medicine VI, Medical University Innsbruck, Innsbruck, Austria
| | - David Haschka
- Department of Internal Medicine VI, Medical University Innsbruck, Innsbruck, Austria
| | | | - Axel Kleinsasser
- Department of Anaesthesia and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Martin Burtscher
- Department of Sports Medicine, Leopold-Franzens University, Innsbruck, Austria
| | - Susanne Trübsbach
- Department of Anaesthesia and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Anthony T Murphy
- Biotechnology Discovery Research, Lilly Research Laboratories, Indianapolis, Indiana, USA
| | - Victor Wroblewski
- Biotechnology Discovery Research, Lilly Research Laboratories, Indianapolis, Indiana, USA
| | - Derrick R Witcher
- Biotechnology Discovery Research, Lilly Research Laboratories, Indianapolis, Indiana, USA
| | - Katarzyna Mleczko-Sanecka
- Department of Pediatric Oncology, Haematology and Immunology, University Hospital of Heidelberg, Heidelberg, Germany
| | - Chiara Vecchi
- Division of Internal Medicine 2 and Center for Hemochromatosis, "Mario Coppo" Liver Research Center, University Hospital of Modena, Modena, Italy
| | - Martina U Muckenthaler
- Department of Pediatric Oncology, Haematology and Immunology, University Hospital of Heidelberg, Heidelberg, Germany
| | - Antonello Pietrangelo
- Division of Internal Medicine 2 and Center for Hemochromatosis, "Mario Coppo" Liver Research Center, University Hospital of Modena, Modena, Italy
| | - Igor Theurl
- Department of Internal Medicine VI, Medical University Innsbruck, Innsbruck, Austria
| | - Günter Weiss
- Department of Internal Medicine VI, Medical University Innsbruck, Innsbruck, Austria
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