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Aznar N, Patel A, Rohena CC, Dunkel Y, Joosen LP, Taupin V, Kufareva I, Farquhar MG, Ghosh P. AMP-activated protein kinase fortifies epithelial tight junctions during energetic stress via its effector GIV/Girdin. eLife 2016; 5. [PMID: 27813479 PMCID: PMC5119889 DOI: 10.7554/elife.20795] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 11/03/2016] [Indexed: 02/06/2023] Open
Abstract
Loss of epithelial polarity impacts organ development and function; it is also oncogenic. AMPK, a key sensor of metabolic stress stabilizes cell-cell junctions and maintains epithelial polarity; its activation by Metformin protects the epithelial barrier against stress and suppresses tumorigenesis. How AMPK protects the epithelium remains unknown. Here, we identify GIV/Girdin as a novel effector of AMPK, whose phosphorylation at a single site is both necessary and sufficient for strengthening mammalian epithelial tight junctions and preserving cell polarity and barrier function in the face of energetic stress. Expression of an oncogenic mutant of GIV (cataloged in TCGA) that cannot be phosphorylated by AMPK increased anchorage-independent growth of tumor cells and helped these cells to evade the tumor-suppressive action of Metformin. This work defines a fundamental homeostatic mechanism by which the AMPK-GIV axis reinforces cell junctions against stress-induced collapse and also provides mechanistic insight into the tumor-suppressive action of Metformin.
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Affiliation(s)
- Nicolas Aznar
- Department of Medicine, University of California, San Diego, San Diego, United States
| | - Arjun Patel
- Department of Medicine, University of California, San Diego, San Diego, United States
| | - Cristina C Rohena
- Department of Medicine, University of California, San Diego, San Diego, United States
| | - Ying Dunkel
- Department of Medicine, University of California, San Diego, San Diego, United States
| | - Linda P Joosen
- Department of Medicine, University of California, San Diego, San Diego, United States
| | - Vanessa Taupin
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, United States
| | - Irina Kufareva
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, San Diego, United States
| | - Marilyn G Farquhar
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, United States
| | - Pradipta Ghosh
- Department of Medicine, University of California, San Diego, San Diego, United States.,Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, United States.,Moores Cancer Center, University of California, San Diego, San Diego, United States
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102
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Landmann M, Sellmann C, Engstler AJ, Ziegenhardt D, Jung F, Brombach C, Bergheim I. Hops (Humulus lupulus) Content in Beer Modulates Effects of Beer on the Liver After Acute Ingestion in Female Mice. Alcohol Alcohol 2016; 52:48-55. [DOI: 10.1093/alcalc/agw060] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 06/07/2016] [Accepted: 07/28/2016] [Indexed: 02/06/2023] Open
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103
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Sellmann C, Jin CJ, Engstler AJ, De Bandt JP, Bergheim I. Oral citrulline supplementation protects female mice from the development of non-alcoholic fatty liver disease (NAFLD). Eur J Nutr 2016; 56:2519-2527. [PMID: 27496089 DOI: 10.1007/s00394-016-1287-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 07/29/2016] [Indexed: 01/08/2023]
Abstract
PURPOSE Impairments of intestinal barrier function are discussed as risk factors for the development and progression of non-alcoholic fatty liver disease (NAFLD). Studies suggest an association between arginine/citrulline homeostasis and the development of liver damages. Here, the effect of an oral L-citrulline (Cit) supplement on the development of a Western-style diet (WSD)-induced NAFLD was determined in mice. METHODS Female 6- to 8-week-old C57BL/6J mice were either pair-fed a liquid Western-style or control diet (C) ± 2.5 g/kg bodyweight Cit for 6 weeks (C + Cit or WSD + Cit). Indices of liver damage, glucose metabolism, intestinal barrier function and NO synthesis were measured. RESULTS While bodyweight gain was similar between groups, markers of glucose metabolism like fasting blood glucose and HOMA index and markers of liver damage like hepatic triglyceride levels, number of neutrophils and plasminogen activator inhibitor-1 protein levels were significantly lower in WSD + Cit-fed mice when compared to WSD-fed mice only. Protein levels of the tight junction proteins occludin and zonula occludens-1 in duodenum were significantly lower in mice fed a WSD when compared to those fed a WSD + Cit (-~70 and -~60 %, respectively, P < 0.05), whereas portal endotoxin levels, concentration of 3-nitrotyrosine protein adducts in duodenum and toll-like receptor-4 mRNA expression in livers of WSD + Cit-fed mice were markedly lower than in WSD-fed mice (-~43 %, P = 0.056; -~80 and -~48 %, respectively, P < 0.05). CONCLUSION Our data suggest that the protective effects of supplementing Cit on the development of NAFLD in mice are associated with a decreased translocation of endotoxin into the portal vein.
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Affiliation(s)
- Cathrin Sellmann
- Institute of Nutritional Sciences, SD Model Systems of Molecular Nutrition, Friedrich-Schiller University Jena, Dornburger Str. 29, 07743, Jena, Germany
| | - Cheng Jun Jin
- Institute of Nutritional Sciences, SD Model Systems of Molecular Nutrition, Friedrich-Schiller University Jena, Dornburger Str. 29, 07743, Jena, Germany
| | - Anna Janina Engstler
- Institute of Nutritional Sciences, SD Model Systems of Molecular Nutrition, Friedrich-Schiller University Jena, Dornburger Str. 29, 07743, Jena, Germany
| | - Jean-Pascal De Bandt
- Nutrition Biology Laboratory EA4466, Faculty of Pharmacy, Paris Descartes University, Sorbonne Paris Cité, Paris, France.,Clinical Chemistry Department, Paris Centre University Hospitals, APHP, Paris, France
| | - Ina Bergheim
- Institute of Nutritional Sciences, SD Model Systems of Molecular Nutrition, Friedrich-Schiller University Jena, Dornburger Str. 29, 07743, Jena, Germany.
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104
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Bischoff SC, Volynets V. Nutritional influences of overfeeding on experimental outcomes in laboratory mice: consequences for gut microbiota and other functional studies. Int J Med Microbiol 2016; 306:328-333. [DOI: 10.1016/j.ijmm.2016.05.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 05/02/2016] [Accepted: 05/30/2016] [Indexed: 01/29/2023] Open
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105
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Gut Microbiota and Lifestyle Interventions in NAFLD. Int J Mol Sci 2016; 17:447. [PMID: 27023533 PMCID: PMC4848903 DOI: 10.3390/ijms17040447] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 02/07/2023] Open
Abstract
The human digestive system harbors a diverse and complex community of microorganisms that work in a symbiotic fashion with the host, contributing to metabolism, immune response and intestinal architecture. However, disruption of a stable and diverse community, termed "dysbiosis", has been shown to have a profound impact upon health and disease. Emerging data demonstrate dysbiosis of the gut microbiota to be linked with non-alcoholic fatty liver disease (NAFLD). Although the exact mechanism(s) remain unknown, inflammation, damage to the intestinal membrane, and translocation of bacteria have all been suggested. Lifestyle intervention is undoubtedly effective at improving NAFLD, however, not all patients respond to these in the same manner. Furthermore, studies investigating the effects of lifestyle interventions on the gut microbiota in NAFLD patients are lacking. A deeper understanding of how different aspects of lifestyle (diet/nutrition/exercise) affect the host-microbiome interaction may allow for a more tailored approach to lifestyle intervention. With gut microbiota representing a key element of personalized medicine and nutrition, we review the effects of lifestyle interventions (diet and physical activity/exercise) on gut microbiota and how this impacts upon NAFLD prognosis.
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106
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Charrez B, Qiao L, Hebbard L. The role of fructose in metabolism and cancer. Horm Mol Biol Clin Investig 2016; 22:79-89. [PMID: 25965509 DOI: 10.1515/hmbci-2015-0009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/02/2015] [Indexed: 02/07/2023]
Abstract
Fructose consumption has dramatically increased in the last 30 years. The principal form has been in the form of high-fructose corn syrup found in soft drinks and processed food. The effect of excessive fructose consumption on human health is only beginning to be understood. Fructose has been confirmed to induce several obesity-related complications associated with the metabolic syndrome. Here we present an overview of fructose metabolism and how it contrasts with that of glucose. In addition, we examine how excessive fructose consumption can affect de novo lipogenesis, insulin resistance, inflammation, and reactive oxygen species production. Fructose can also induce a change in the gut permeability and promote the release of inflammatory factors to the liver, which has potential implications in increasing hepatic inflammation. Moreover, fructose has been associated with colon, pancreas, and liver cancers, and we shall discuss the evidence for these observations. Taken together, data suggest that sustained fructose consumption should be curtailed as it is detrimental to long-term human health.
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107
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Pang J, Xi C, Huang X, Cui J, Gong H, Zhang T. Effects of Excess Energy Intake on Glucose and Lipid Metabolism in C57BL/6 Mice. PLoS One 2016; 11:e0146675. [PMID: 26745179 PMCID: PMC4706434 DOI: 10.1371/journal.pone.0146675] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 12/21/2015] [Indexed: 11/18/2022] Open
Abstract
Excess energy intake correlates with the development of metabolic disorders. However, different energy-dense foods have different effects on metabolism. To compare the effects of a high-fat diet, a high-fructose diet and a combination high-fat/high-fructose diet on glucose and lipid metabolism, male C57BL/6 mice were fed with one of four different diets for 3 months: standard chow; standard diet and access to fructose water; a high fat diet; and a high fat diet with fructose water. After 3 months of feeding, the high-fat and the combined high-fat/high-fructose groups showed significantly increased body weights, accompanied by hyperglycemia and insulin resistance; however, the high-fructose group was not different from the control group. All three energy-dense groups showed significantly higher visceral fat weights, total cholesterol concentrations, and low-density lipoprotein cholesterol concentrations compared with the control group. Assays of basal metabolism showed that the respiratory quotient of the high-fat, the high-fructose, and the high-fat/high-fructose groups decreased compared with the control group. The present study confirmed the deleterious effect of high energy diets on body weight and metabolism, but suggested that the energy efficiency of the high-fructose diet was much lower than that of the high-fat diet. In addition, fructose supplementation did not worsen the detrimental effects of high-fat feeding alone on metabolism in C57BL/6 mice.
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Affiliation(s)
- Jing Pang
- The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, China
| | - Chao Xi
- College of Life Sciences, Beijing Normal University, Beijing, China
| | - Xiuqing Huang
- The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, China
| | - Ju Cui
- The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, China
| | - Huan Gong
- The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, China
| | - Tiemei Zhang
- The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing, China
- * E-mail:
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Morinaga M, Kon K, Saito H, Arai K, Kusama H, Uchiyama A, Yamashina S, Ikejima K, Watanabe S. Sodium 4-phenylbutyrate prevents murine dietary steatohepatitis caused by trans-fatty acid plus fructose. J Clin Biochem Nutr 2015; 57:183-91. [PMID: 26566303 PMCID: PMC4639592 DOI: 10.3164/jcbn.15-75] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 06/30/2015] [Indexed: 12/19/2022] Open
Abstract
Excess consumption of trans-fatty acid could increase the risk of non-alcoholic steatohepatitis (NASH); however, treatment targeting trans-fatty acid-induced NASH has not been examined. Here we focused on the influence of trans-fatty acid intake on endoplasmic reticulum (ER) stress in hepatocytes, so we investigated the effect of the chemical chaperone 4-phenylbutyric acid (PBA), on trans-fatty acid-caused steatohepatitis using diabetic KK-A(y) mice. Elaidic acid (EA, trans-fatty acid) alone did not cause definitive liver injury. In contrast, EA plus low-dose fructose induced extensive apoptosis in hepatocytes with severe fat accumulation. EA plus fructose significantly increased ER stress markers such as glucose-regulated protein 78 (GRP78), eukaryotic initiation factor 2α (eIF2α) and phosphorylated c-jun N-terminal kinase (JNK), while PBA significantly reduced this response. In vitro, EA promoted expression of GRP78 and phosphorylation of eIF2α in primary-cultured hepatocytes. EA also increased hepatocellular susceptibility to low-dose tert-butyl hydroperoxide. Treatment with PBA significantly reduced these responses. In conclusion, EA potentiates susceptibly to non-hazardous dose of fructose, and increases ER and oxidative stress. PBA improved steatohepatitis induced by EA plus fructose through amelioration of ER stress. Therefore, ER stress-targeted therapy using a chemical chaperone is a promising novel strategy for trans-fatty acid-induced steatohepatitis.
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Affiliation(s)
- Maki Morinaga
- Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Kazuyoshi Kon
- Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Hiroaki Saito
- Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Kumiko Arai
- Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Hiromi Kusama
- Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Akira Uchiyama
- Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Shunhei Yamashina
- Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Kenichi Ikejima
- Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Sumio Watanabe
- Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
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Supplementation of sodium butyrate protects mice from the development of non-alcoholic steatohepatitis (NASH). Br J Nutr 2015; 114:1745-55. [PMID: 26450277 DOI: 10.1017/s0007114515003621] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Overnutrition, insulin resistance and an impaired intestinal barrier function are discussed as critical factors in the development of non-alcoholic fatty liver disease. Not only butyrate-producing probiotics as well as supplementation of sodium butyrate (SoB) have been suggested to bear protective effects on liver damage of various aetiologies. However, whether an oral consumption of SoB has a protective effect on Western-style diet (WSD)-induced non-alcoholic steatohepatitis (NASH) and if so molecular mechanism involved has not yet been determined. Eight-week-old C57BL/6J mice were pair-fed either a liquid control or WSD±0·6 g/kg body weight SoB. After 6 weeks, markers of liver damage, inflammation, toll-like receptor (TLR)-4 signalling, lipid peroxidation and glucose as well as lipid metabolism were determined in the liver tissue. Tight junction protein levels were determined in the duodenal tissue. SoB supplementation had no effects on the body weight gain or liver weight of WSD-fed mice, whereas liver steatosis and hepatic inflammation were significantly decreased (e.g. less inflammatory foci and neutrophils) when compared with mice fed only a WSD. Tight junction protein levels in duodenum, hepatic mRNA expression of TLR-4 and sterol regulatory element-binding protein 1c were altered similarly in both WSD groups when compared with controls, whereas protein levels of myeloid differentiation primary response gene 88, inducible nitric oxide synthase, 4-hydroxynonenal protein adducts and F4/80 macrophages were only significantly induced in livers of mice fed only the WSD. In summary, these data suggest that an oral supplementation of SoB protects mice from inflammation in the liver and thus from the development of WSD-induced NASH.
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110
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Sellmann C, Jin CJ, Degen C, De Bandt JP, Bergheim I. Oral Glutamine Supplementation Protects Female Mice from Nonalcoholic Steatohepatitis. J Nutr 2015; 145:2280-6. [PMID: 26246326 DOI: 10.3945/jn.115.215517] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 07/15/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Genetic factors, a diet rich in fat and sugar, and an impaired intestinal barrier function are critical in the development of nonalcoholic steatohepatitis (NASH). The nonessential amino acid glutamine (Gln) has been suggested to have protective effects on intestinal barrier function but also against the development of liver diseases of various etiologies. OBJECTIVE The effect of oral Gln supplementation on the development of Western-style diet (WSD)-induced NASH in mice was assessed. METHODS Female 6- to 8-wk-old C57BL/6J mice were pair-fed a control (C) diet or a WSD alone or supplemented with 2.1 g l-Gln/kg body weight for 6 wk (C+Gln or WSD+Gln). Indexes of liver damage, lipid peroxidation, and glucose metabolism and endotoxin concentrations were measured. RESULTS Although Gln supplementation had no effect on the loss of the tight junction protein occludin, the increased portal endotoxin and fasting glucose concentrations found in WSD-fed mice, markers of liver damage (e.g., nonalcoholic fatty liver disease activity score and number of neutrophils in the liver) were significantly lower in the WSD+Gln group than in the WSD group (~47% and ~60% less, respectively; P < 0.05). Concentrations of inducible nitric oxide synthase (iNOS) protein and 3-nitrotyrosin protein adducts were significantly higher in livers of WSD-fed mice than in all other groups (~8.6- and ~1.9-fold higher, respectively, compared with the C group; P < 0.05) but did not differ between WSD+Gln-, C-, and C+Gln-fed mice. Hepatic tumor necrosis factor α and plasminogen activator inhibitor 1 concentrations were significantly higher in WSD-fed mice (~1.6- and ~1.8-fold higher, respectively; P < 0.05) but not in WSD+Gln-fed mice compared with C mice. CONCLUSION Our data suggest that the protective effects of oral Gln supplementation on the development of WSD-induced NASH in mice are associated with protection against the induction of iNOS and lipid peroxidation in the liver.
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Affiliation(s)
- Cathrin Sellmann
- Institute of Nutritional Sciences, SD Model Systems of Molecular Nutrition, Friedrich-Schiller University Jena, Jena, Germany
| | - Cheng Jun Jin
- Institute of Nutritional Sciences, SD Model Systems of Molecular Nutrition, Friedrich-Schiller University Jena, Jena, Germany
| | - Christian Degen
- Institute of Nutritional Sciences, SD Model Systems of Molecular Nutrition, Friedrich-Schiller University Jena, Jena, Germany
| | - Jean-Pascal De Bandt
- Nutrition Biology Laboratory EA4466, Faculty of Pharmacy, Paris Descartes University, Sorbonne Paris Cité, Paris, France; and Clinical Chemistry Department, Paris Center University Hospitals, Public Assistance Hospitals of Paris, Paris, France
| | - Ina Bergheim
- Institute of Nutritional Sciences, SD Model Systems of Molecular Nutrition, Friedrich-Schiller University Jena, Jena, Germany;
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Song BJ, Akbar M, Abdelmegeed MA, Byun K, Lee B, Yoon SK, Hardwick JP. Mitochondrial dysfunction and tissue injury by alcohol, high fat, nonalcoholic substances and pathological conditions through post-translational protein modifications. Redox Biol 2015; 3:109-23. [PMID: 25465468 PMCID: PMC4297931 DOI: 10.1016/j.redox.2014.10.004] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 10/21/2014] [Accepted: 10/23/2014] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are critically important in providing cellular energy ATP as well as their involvement in anti-oxidant defense, fat oxidation, intermediary metabolism and cell death processes. It is well-established that mitochondrial functions are suppressed when living cells or organisms are exposed to potentially toxic agents including alcohol, high fat diets, smoking and certain drugs or in many pathophysiological states through increased levels of oxidative/nitrative stress. Under elevated nitroxidative stress, cellular macromolecules proteins, DNA, and lipids can undergo different oxidative modifications, leading to disruption of their normal, sometimes critical, physiological functions. Recent reports also indicated that many mitochondrial proteins are modified via various post-translation modifications (PTMs) and primarily inactivated. Because of the recently-emerging information, in this review, we specifically focus on the mechanisms and roles of five major PTMs (namely oxidation, nitration, phosphorylation, acetylation, and adduct formation with lipid-peroxides, reactive metabolites, or advanced glycation end products) in experimental models of alcoholic and nonalcoholic fatty liver disease as well as acute hepatic injury caused by toxic compounds. We also highlight the role of the ethanol-inducible cytochrome P450-2E1 (CYP2E1) in some of these PTM changes. Finally, we discuss translational research opportunities with natural and/or synthetic anti-oxidants, which can prevent or delay the onset of mitochondrial dysfunction, fat accumulation and tissue injury. Hepatotoxic agents including alcohol and high fat elevate nitroxidative stress. Increased nitroxidative stress promotes post-translational protein modifications. Post-translational protein modifications of many proteins lead to their inactivation. Inactivation of mitochondrial proteins contributes to mitochondrial dysfunction. Mitochondrial dysfunction contributes to necrotic or apoptotic tissue injury.
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Song BJ, Akbar M, Jo I, Hardwick JP, Abdelmegeed MA. Translational Implications of the Alcohol-Metabolizing Enzymes, Including Cytochrome P450-2E1, in Alcoholic and Nonalcoholic Liver Disease. ADVANCES IN PHARMACOLOGY 2015; 74:303-72. [PMID: 26233911 DOI: 10.1016/bs.apha.2015.04.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Fat accumulation (hepatic steatosis) in alcoholic and nonalcoholic fatty liver disease is a potentially pathologic condition which can progress to steatohepatitis (inflammation), fibrosis, cirrhosis, and carcinogenesis. Many clinically used drugs or some alternative medicine compounds are also known to cause drug-induced liver injury, which can further lead to fulminant liver failure and acute deaths in extreme cases. During liver disease process, certain cytochromes P450 such as the ethanol-inducible cytochrome P450-2E1 (CYP2E1) and CYP4A isozymes can be induced and/or activated by alcohol and/or high-fat diets and pathophysiological conditions such as fasting, obesity, and diabetes. Activation of these P450 isozymes, involved in the metabolism of ethanol, fatty acids, and various drugs, can produce reactive oxygen/nitrogen species directly and/or indirectly, contributing to oxidative modifications of DNA/RNA, proteins and lipids. In addition, aldehyde dehydrogenases including the mitochondrial low Km aldehyde dehydrogenase-2 (ALDH2), responsible for the metabolism of acetaldehyde and lipid aldehydes, can be inactivated by various hepatotoxic agents. These highly reactive acetaldehyde and lipid peroxides, accumulated due to ALDH2 suppression, can interact with cellular macromolecules DNA/RNA, lipids, and proteins, leading to suppression of their normal function, contributing to DNA mutations, endoplasmic reticulum stress, mitochondrial dysfunction, steatosis, and cell death. In this chapter, we specifically review the roles of the alcohol-metabolizing enzymes including the alcohol dehydrogenase, ALDH2, CYP2E1, and other enzymes in promoting liver disease. We also discuss translational research opportunities with natural and/or synthetic antioxidants, which can prevent or delay the onset of inflammation and liver disease.
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Affiliation(s)
- Byoung-Joon Song
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA.
| | - Mohammed Akbar
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA
| | - Inho Jo
- Department of Molecular Medicine, Ewha Womans University School of Medicine, Seoul, South Korea
| | - James P Hardwick
- Biochemistry and Molecular Pathology in Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Mohamed A Abdelmegeed
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA
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Sellmann C, Priebs J, Landmann M, Degen C, Engstler AJ, Jin CJ, Gärttner S, Spruss A, Huber O, Bergheim I. Diets rich in fructose, fat or fructose and fat alter intestinal barrier function and lead to the development of nonalcoholic fatty liver disease over time. J Nutr Biochem 2015; 26:1183-92. [PMID: 26168700 DOI: 10.1016/j.jnutbio.2015.05.011] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 05/08/2015] [Accepted: 05/13/2015] [Indexed: 02/07/2023]
Abstract
General overnutrition but also a diet rich in certain macronutrients, age, insulin resistance and an impaired intestinal barrier function may be critical factors in the development of nonalcoholic fatty liver disease (NAFLD). Here the effect of chronic intake of diets rich in different macronutrients, i.e. fructose and/or fat on liver status in mice, was studied over time. C57BL/6J mice were fed plain water, 30% fructose solution, a high-fat diet or a combination of both for 8 and 16 weeks. Indices of liver damage, toll-like receptor 4 (TLR-4) signaling cascade, macrophage polarization and insulin resistance in the liver and intestinal barrier function were analyzed. Chronic exposure to a diet rich in fructose and/or fat was associated with the development of hepatic steatosis that progressed with time to steatohepatitis in mice fed a combination of macronutrients. The development of NAFLD was also associated with a marked reduction of the mRNA expression of insulin receptor, whereas hepatic expressions of TLR-4, myeloid differentiation primary response gene 88 and markers of M1 polarization of macrophages were induced in comparison to controls. Bacterial endotoxin levels in portal plasma were found to be increased while levels of the tight junction protein occludin and zonula occludens 1 were found to be significantly lower in the duodenum of all treated groups after 8 and 16 weeks. Our data suggest that chronic intake of fructose and/or fat may lead to the development of NAFLD over time and that this is associated with an increased translocation of bacterial endotoxin.
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Affiliation(s)
- Cathrin Sellmann
- Institute of Nutritional Sciences, Model Systems of Molecular Nutrition, Friedrich-Schiller-University Jena, Jena, Germany
| | - Josephine Priebs
- Institute of Nutritional Sciences, Model Systems of Molecular Nutrition, Friedrich-Schiller-University Jena, Jena, Germany
| | - Marianne Landmann
- Institute of Nutritional Sciences, Model Systems of Molecular Nutrition, Friedrich-Schiller-University Jena, Jena, Germany
| | - Christian Degen
- Institute of Nutritional Sciences, Model Systems of Molecular Nutrition, Friedrich-Schiller-University Jena, Jena, Germany
| | - Anna Janina Engstler
- Institute of Nutritional Sciences, Model Systems of Molecular Nutrition, Friedrich-Schiller-University Jena, Jena, Germany
| | - Cheng Jun Jin
- Institute of Nutritional Sciences, Model Systems of Molecular Nutrition, Friedrich-Schiller-University Jena, Jena, Germany
| | - Stefanie Gärttner
- Institute of Nutritional Sciences, Model Systems of Molecular Nutrition, Friedrich-Schiller-University Jena, Jena, Germany
| | - Astrid Spruss
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - Otmar Huber
- Department of Biochemistry II, University Hospital Jena, Friedrich-Schiller-University Jena, Jena, Germany; Center of Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | - Ina Bergheim
- Institute of Nutritional Sciences, Model Systems of Molecular Nutrition, Friedrich-Schiller-University Jena, Jena, Germany.
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Zhang X, Zhang JH, Chen XY, Hu QH, Wang MX, Jin R, Zhang QY, Wang W, Wang R, Kang LL, Li JS, Li M, Pan Y, Huang JJ, Kong LD. Reactive oxygen species-induced TXNIP drives fructose-mediated hepatic inflammation and lipid accumulation through NLRP3 inflammasome activation. Antioxid Redox Signal 2015; 22:848-70. [PMID: 25602171 PMCID: PMC4367240 DOI: 10.1089/ars.2014.5868] [Citation(s) in RCA: 187] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AIMS Increased fructose consumption predisposes the liver to nonalcoholic fatty liver disease (NAFLD), but the mechanisms are elusive. Thioredoxin-interacting protein (TXNIP) links oxidative stress to NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation and this signaling axis may be involved in fructose-induced NAFLD. Here, we explore the role of reactive oxygen species (ROS)-induced TXNIP overexpression in fructose-mediated hepatic NLRP3 inflammasome activation, inflammation, and lipid accumulation. RESULTS Rats were fed a 10% fructose diet for 8 weeks and treated with allopurinol and quercetin during the last 4 weeks. Five millimolars of fructose-exposed hepatocytes (primary rat hepatocytes, rat hepatic parenchymal cells [RHPCs], HLO2, HepG2) were co-incubated with antioxidants or caspase-1 inhibitor or subjected to TXNIP or NLRP3 siRNA interference. Fructose induced NLRP3 inflammasome activation and pro-inflammatory cytokine secretion, janus-activated kinase 2/signal transducers and activators of transcription 3-mediated inflammatory signaling, and expression alteration of lipid metabolism-related genes in cultured hepatocytes and rat livers. NLRP3 silencing and caspase-1 suppression blocked these effects in primary rat hepatocytes and RHPCs, confirming that inflammasome activation alters hepatocyte lipid metabolism. Hepatocellular ROS and TXNIP were increased in animal and cell models. TXNIP silencing blocked NLRP3 inflammasome activation, inflammation, and lipid metabolism perturbations but not ROS induction in fructose-exposed hepatocytes, whereas antioxidants addition abrogated TXNIP induction and diminished the detrimental effects in fructose-exposed hepatocytes and rat livers. INNOVATION AND CONCLUSIONS This study provides a novel mechanism for fructose-induced NAFLD pathogenesis by which the ROS-TXNIP pathway mediates hepatocellular NLRP3 inflammasome activation, inflammation and lipid accumulation. Antioxidant-based interventions can inhibit the ROS-TXNIP pathway.
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Affiliation(s)
- Xian Zhang
- 1 State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University , Nanjing, People's Republic of China
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Hur KY, Lee MS. New mechanisms of metformin action: Focusing on mitochondria and the gut. J Diabetes Investig 2015; 6:600-9. [PMID: 26543531 PMCID: PMC4627534 DOI: 10.1111/jdi.12328] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 12/26/2014] [Accepted: 01/05/2015] [Indexed: 12/12/2022] Open
Abstract
The most well-known mechanism of metformin action, one of the most commonly prescribed antidiabetic drugs, is adenosine monophosphate-activated protein kinase activation; however, recent investigations have shown that adenosine monophosphate-activated protein kinase-independent pathways can explain some of metformin's beneficial metabolic effects as well as undesirable side-effects. Such novel pathways include induction of mitochondrial stress, inhibition of mitochondrial shuttles, alteration of intestinal microbiota, suppression of glucagon signaling, activation of autophagy, attenuation of inflammasome activation, induction of incretin receptors and reduction of terminal endoplasmic reticulum stress. Together, these studies have broadened our understanding of the mechanisms of antidiabetic agents as well as the pathogenic mechanism of diabetes itself. The results of such investigations might help to identify new target molecules and pathways for treatment of diabetes and metabolic syndrome, and could also have broad implications in diseases other than diabetes. Accordingly, new antidiabetic drugs with better efficacy and fewer adverse effects will likely result from these studies.
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Affiliation(s)
- Kyu Yeon Hur
- Division of Endocrinology & Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Korea
| | - Myung-Shik Lee
- Division of Endocrinology & Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Korea
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Develi-Is S, Ozen G, Bekpinar S, Topal G, Unlucerci Y, Dogan BSU, Uysal M. Resveratrol improves high-fructose-induced vascular dysfunction in rats. Can J Physiol Pharmacol 2014; 92:1021-7. [DOI: 10.1139/cjpp-2014-0245] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
High levels of fructose in the diet results in metabolic abnormalities and vascular disorders. In this study, the effect of resveratrol (RES) on vascular relaxation and contraction responses was examined in the aorta of high-fructose (HFr)-fed rats. mRNA expressions of aortic sirtuin 1 (SIRT1), GLUT5, and aldolase B were also investigated. Rats were given fructose (30%) and (or) RES (50 mg·L−1) in their drinking water for 8 weeks. In the HFr-fed rats, plasma levels of arginine and the ratio of arginine:asymmetric dimethylarginine (ADMA) decreased, whereas leptin levels increased. Decreased relaxation and increased contractile responses were detected in aortic rings. However, the aortic expressions of SIRT1, GLUT5, and aldolase B remained unchanged. RES treatment restored HFr-induced vascular dysfunction without improvements in insulin resistance. Treatment of HFr-fed rats with RES increased plasma levels of arginine and the l-arginine:ADMA ratio, and decreased plasma levels of leptin. RES increased SIRT1 expression, but decreased the expression of GLUT5 and aldolase B in aortas from HFr-fed rats. These results suggest that RES contributes to the restoration of HFr-induced vascular dysfunction in rats, at least in part, by up-regulation of SIRT 1 and down-regulation of GLUT5 and aldolase B in the aorta. Moreover, RES may have a positive influence on vasculature by partly restoring the plasma arginine:ADMA ratio and leptin levels.
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Affiliation(s)
- Seval Develi-Is
- Department of Biochemistry, Istanbul Faculty of Medicine, Istanbul University, Capa 34093, Istanbul, Turkey
| | - Gulsev Ozen
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Beyazit, 34116, Istanbul, Turkey
| | - Seldag Bekpinar
- Department of Biochemistry, Istanbul Faculty of Medicine, Istanbul University, Capa 34093, Istanbul, Turkey
| | - Gokce Topal
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Beyazit, 34116, Istanbul, Turkey
| | - Yesim Unlucerci
- Department of Biochemistry, Istanbul Faculty of Medicine, Istanbul University, Capa 34093, Istanbul, Turkey
| | - B. Sonmez Uydes Dogan
- Department of Pharmacology, Faculty of Pharmacy, Istanbul University, Beyazit, 34116, Istanbul, Turkey
| | - Mujdat Uysal
- Department of Biochemistry, Istanbul Faculty of Medicine, Istanbul University, Capa 34093, Istanbul, Turkey
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117
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Intestinal permeability--a new target for disease prevention and therapy. BMC Gastroenterol 2014; 14:189. [PMID: 25407511 PMCID: PMC4253991 DOI: 10.1186/s12876-014-0189-7] [Citation(s) in RCA: 1084] [Impact Index Per Article: 108.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 10/17/2014] [Indexed: 02/06/2023] Open
Abstract
Data are accumulating that emphasize the important role of the intestinal barrier and intestinal permeability for health and disease. However, these terms are poorly defined, their assessment is a matter of debate, and their clinical significance is not clearly established. In the present review, current knowledge on mucosal barrier and its role in disease prevention and therapy is summarized. First, the relevant terms 'intestinal barrier' and 'intestinal permeability' are defined. Secondly, the key element of the intestinal barrier affecting permeability are described. This barrier represents a huge mucosal surface, where billions of bacteria face the largest immune system of our body. On the one hand, an intact intestinal barrier protects the human organism against invasion of microorganisms and toxins, on the other hand, this barrier must be open to absorb essential fluids and nutrients. Such opposing goals are achieved by a complex anatomical and functional structure the intestinal barrier consists of, the functional status of which is described by 'intestinal permeability'. Third, the regulation of intestinal permeability by diet and bacteria is depicted. In particular, potential barrier disruptors such as hypoperfusion of the gut, infections and toxins, but also selected over-dosed nutrients, drugs, and other lifestyle factors have to be considered. In the fourth part, the means to assess intestinal permeability are presented and critically discussed. The means vary enormously and probably assess different functional components of the barrier. The barrier assessments are further hindered by the natural variability of this functional entity depending on species and genes as well as on diet and other environmental factors. In the final part, we discuss selected diseases associated with increased intestinal permeability such as critically illness, inflammatory bowel diseases, celiac disease, food allergy, irritable bowel syndrome, and--more recently recognized--obesity and metabolic diseases. All these diseases are characterized by inflammation that might be triggered by the translocation of luminal components into the host. In summary, intestinal permeability, which is a feature of intestinal barrier function, is increasingly recognized as being of relevance for health and disease, and therefore, this topic warrants more attention.
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Landmann M, Kanuri G, Spruss A, Stahl C, Bergheim I. Oral intake of chicoric acid reduces acute alcohol-induced hepatic steatosis in mice. Nutrition 2014; 30:882-9. [PMID: 24985007 DOI: 10.1016/j.nut.2013.11.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 10/25/2013] [Accepted: 11/12/2013] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Acute and chronic consumption of alcohol can alter intestinal barrier function thereby increasing portal endotoxin levels subsequently leading to an activation of toll-like receptor (TLR) 4-dependent signaling cascades, elevated levels of reactive oxygen species and induction of tumor necrosis factor α in the liver. Recent studies suggest that chicoric acid found in Echinacea pupurea, chicory, and other plants, may possess antioxidant and anti-inflammatory effects. The aim of the present study was to determine if chicoric acid can reduce acute alcohol-induced liver damage. METHODS Female mice were given chicoric acid orally (4 mg/kg body weight) for 4 d before acute ethanol administration (6 g/kg body weight). Furthermore, the effect of chicoric acid on the lipopolysaccharide (LPS)-dependent activation in an in vitro model of Kupffer cells (RAW264.7 macrophages) was assessed. RESULTS Acute alcohol ingestion caused a significant increase in hepatic triacylglycerols accumulation, which was associated with increased protein levels of the inducible nitric oxide synthase (iNOS), 4-hydroxynonenal protein adducts, and active plasminogen activator inhibitor 1 protein in the liver. Pretreatment of animals with chicoric acid significantly attenuated these effects of alcohol on the liver. In LPS-treated RAW264.7 macrophages, pretreatment with chicoric acid significantly suppressed LPS-induced mRNA expression of iNOS and tumor necrosis factor α. CONCLUSION These data suggest that chicoric acid may reduce acute alcohol-induced steatosis in mice through interfering with the induction of iNOS and iNOS-dependent signaling cascades in the liver.
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Affiliation(s)
- Marianne Landmann
- SD Model Systems of Molecular Nutrition, Friedrich-Schiller University, Jena, Germany
| | - Giridhar Kanuri
- SD Model Systems of Molecular Nutrition, Friedrich-Schiller University, Jena, Germany
| | - Astrid Spruss
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - Carolin Stahl
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
| | - Ina Bergheim
- SD Model Systems of Molecular Nutrition, Friedrich-Schiller University, Jena, Germany.
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119
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McCarty MF, DiNicolantonio JJ. The cardiometabolic benefits of glycine: Is glycine an 'antidote' to dietary fructose? Open Heart 2014; 1:e000103. [PMID: 25332814 PMCID: PMC4195924 DOI: 10.1136/openhrt-2014-000103] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/26/2014] [Indexed: 02/06/2023] Open
Affiliation(s)
| | - James J DiNicolantonio
- Department of Preventive Cardiology , Saint Luke's Mid America Heart Institute , Kansas City, Missouri , USA
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120
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Horton F, Wright J, Smith L, Hinton PJ, Robertson MD. Increased intestinal permeability to oral chromium (51 Cr) -EDTA in human Type 2 diabetes. Diabet Med 2014; 31:559-63. [PMID: 24236770 DOI: 10.1111/dme.12360] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/17/2013] [Accepted: 11/12/2013] [Indexed: 02/07/2023]
Abstract
OBJECTIVE In animal models of obesity and Type 2 diabetes, permeability of the intestine is increased because of impairment of tight junction proteins, allowing translocation of bacterial endotoxin and resulting in low-grade systemic inflammation. This has yet to be demonstrated in humans. The objective of this study was the demonstration of increased intestinal permeability in human Type 2 diabetes. METHODS We examined intestinal permeability using chromium ((51) Cr)-EDTA urinary recovery in twenty well-controlled men with Type 2 diabetes compared with control subjects matched for age, gender and BMI. RESULTS Intestinal permeability was significantly increased (P = 0.002) in the diabetic group and was correlated to increased levels of systemic inflammatory markers high-sensitivity C-reactive protein (r = 0.694, P = 0.001), interleukin 6 (r = 0.548, P = 0.012) and tumour necrosis factor alpha (r = 0.564, P = 0.010). CONCLUSION This is the first demonstration that increased intestinal permeability may be a feature of human Type 2 diabetes.
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Affiliation(s)
- F Horton
- Department of Nuclear Medicine, Royal Surrey County Hospital, Guildford, UK
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121
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Chiu S, Sievenpiper JL, de Souza RJ, Cozma AI, Mirrahimi A, Carleton AJ, Ha V, Di Buono M, Jenkins AL, Leiter LA, Wolever TMS, Don-Wauchope AC, Beyene J, Kendall CWC, Jenkins DJA. Effect of fructose on markers of non-alcoholic fatty liver disease (NAFLD): a systematic review and meta-analysis of controlled feeding trials. Eur J Clin Nutr 2014; 68:416-23. [PMID: 24569542 PMCID: PMC3975811 DOI: 10.1038/ejcn.2014.8] [Citation(s) in RCA: 205] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 10/12/2013] [Accepted: 11/12/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND/OBJECTIVES In the absence of consistent clinical evidence, there are concerns that fructose contributes to non-alcoholic fatty liver disease (NAFLD). To determine the effect of fructose on markers of NAFLD, we conducted a systematic review and meta-analysis of controlled feeding trials. SUBJECTS/METHODS We searched MEDLINE, EMBASE, CINAHL and the Cochrane Library (through 3 September 2013). We included relevant trials that involved a follow-up of ≥ 7 days. Two reviewers independently extracted relevant data. Data were pooled by the generic inverse variance method using random effects models and expressed as standardized mean difference (SMD) for intrahepatocellular lipids (IHCL) and mean difference (MD) for alanine aminotransferase (ALT). Inter-study heterogeneity was assessed (Cochran Q statistic) and quantified (I(2) statistic). RESULTS Eligibility criteria were met by eight reports containing 13 trials in 260 healthy participants: seven isocaloric trials, in which fructose was exchanged isocalorically for other carbohydrates, and six hypercaloric trials, in which the diet was supplemented with excess energy (+21-35% energy) from high-dose fructose (+104-220 g/day). Although there was no effect of fructose in isocaloric trials, fructose in hypercaloric trials increased both IHCL (SMD=0.45 (95% confidence interval (CI): 0.18, 0.72)) and ALT (MD=4.94 U/l (95% CI: 0.03, 9.85)). LIMITATIONS Few trials were available for inclusion, most of which were small, short (≤ 4 weeks), and of poor quality. CONCLUSIONS Isocaloric exchange of fructose for other carbohydrates does not induce NAFLD changes in healthy participants. Fructose providing excess energy at extreme doses, however, does raise IHCL and ALT, an effect that may be more attributable to excess energy than fructose. Larger, longer and higher-quality trials of the effect of fructose on histopathological NAFLD changes are required.
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Affiliation(s)
- S Chiu
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Department of Human Biology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - J L Sievenpiper
- 1] Department of Pathology and Molecular Medicine, Faculty of Health Sciences, Hamilton, ON, Canada [2] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada [3] The Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
| | - R J de Souza
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada [3] Department of Clinical Epidemiology & Biostatistics, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - A I Cozma
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada
| | - A Mirrahimi
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada
| | - A J Carleton
- 1] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada [2] Department of Undergraduate Medical Education (MD Program), Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - V Ha
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada
| | - M Di Buono
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Heart and Stroke Foundation of Ontario, Toronto, ON, Canada [3] American Heart Association, Dallas, TX, USA
| | - A L Jenkins
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada
| | - L A Leiter
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada [3] Keenan Research Center of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada [4] Division of Endocrinology, St Michael's Hospital, Toronto, ON, Canada [5] Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - T M S Wolever
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada [3] Keenan Research Center of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada [4] Division of Endocrinology, St Michael's Hospital, Toronto, ON, Canada [5] Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - A C Don-Wauchope
- 1] Department of Pathology and Molecular Medicine, Faculty of Health Sciences, Hamilton, ON, Canada [2] Division of Clinical Chemistry and Immunology, Hamilton Regional Laboratory Medicine Program, Hamilton, ON, Canada
| | - J Beyene
- 1] Department of Clinical Epidemiology & Biostatistics, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada [2] The Dalla Lana School of Public Health, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [3] Child Health Evaluative Sciences (CHES), The Hospital for Sick Children Research Institute, Toronto, ON, Canada
| | - C W C Kendall
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada [3] College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - D J A Jenkins
- 1] Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada [2] Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modification Centre, St Michael's Hospital, Toronto, ON, Canada [3] Keenan Research Center of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada [4] Division of Endocrinology, St Michael's Hospital, Toronto, ON, Canada [5] Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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122
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Fructose induced endotoxemia in pediatric nonalcoholic Fatty liver disease. Int J Hepatol 2014; 2014:560620. [PMID: 25328713 PMCID: PMC4195259 DOI: 10.1155/2014/560620] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 09/09/2014] [Accepted: 09/10/2014] [Indexed: 02/06/2023] Open
Abstract
In preclinical studies of fructose-induced NAFLD, endotoxin appears to play an important role. We retrospectively examined samples from three pediatric cohorts (1) to investigate whether endotoxemia is associated with the presence of hepatic steatosis; (2) to evaluate postprandial endotoxin levels in response to fructose beverage in an acute 24-hour feeding challenge, and (3) to determine the change of fasting endotoxin amounts in a 4-week randomized controlled trial comparing fructose to glucose beverages in NAFLD. We found that adolescents with hepatic steatosis had elevated endotoxin levels compared to obese controls and that the endotoxin level correlated with insulin resistance and several inflammatory cytokines. In a 24-hour feeding study, endotoxin levels in NAFLD adolescents increased after fructose beverages (consumed with meals) as compared to healthy children. Similarly, endotoxin was significantly increased after adolescents consumed fructose beverages for 2 weeks and remained high although not significantly at 4 weeks. In conclusion, these data provide support for the concept of low level endotoxemia contributing to pediatric NAFLD and the possible role of fructose in this process. Further studies are needed to determine if manipulation of the microbiome or other methods of endotoxin reduction would be useful as a therapy for pediatric NAFLD.
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123
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Reichold A, Brenner SA, Spruss A, Förster-Fromme K, Bergheim I, Bischoff SC. Bifidobacterium adolescentis protects from the development of nonalcoholic steatohepatitis in a mouse model. J Nutr Biochem 2013; 25:118-25. [PMID: 24445036 DOI: 10.1016/j.jnutbio.2013.09.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 07/18/2013] [Accepted: 09/10/2013] [Indexed: 02/07/2023]
Abstract
To investigate the hypothesis that an oral supplementation of Bifidobacterium adolescentis protects against a diet-induced nonalcoholic steatohepatitis in a mouse model, C57BL/6 mice were fed either a Western-style or a control diet±tap water fortified with B. adolescentis (5×10(7) cfu/ml) ad libitum for 12 weeks. Mice fed a Western-style diet gained significantly more weight than mice fed a control diet and developed a mild steatohepatitis. Western-style diet fed groups concomitantly treated with B. adolescentis had significantly decreased liver damage, whereas portal endotoxin levels and toll-like receptor-4 protein levels as well as myeloid differentiation factor 88 mRNA were increased in livers of both Western-style diet fed groups. The protective effects of the B. adolescentis were associated with a significant attenuation of the formation of reactive oxygen species, activation of nuclear factor κB (NFκB) and induction of markers of inflammation in the liver. Taken together, our data suggest that an oral supplementation of the B. adolescentis attenuates diet-induced steatohepatitis, and this effect is associated with prevention from lipid peroxidation, NFκB activation and finally inflammation in the liver.
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Affiliation(s)
- Astrid Reichold
- Department of Nutritional Medicine, University of Hohenheim, Fruwirthstr. 12, 70599 Stuttgart, Germany
| | - Sibylle A Brenner
- Department of Nutritional Medicine, University of Hohenheim, Fruwirthstr. 12, 70599 Stuttgart, Germany
| | - Astrid Spruss
- Department of Nutritional Medicine, University of Hohenheim, Fruwirthstr. 12, 70599 Stuttgart, Germany
| | - Karin Förster-Fromme
- Department of Nutritional Medicine, University of Hohenheim, Fruwirthstr. 12, 70599 Stuttgart, Germany
| | - Ina Bergheim
- Department of Model systems of molecular nutritional sciences, Institute of Nutrition, University of Jena, Dornburgerstr. 25, 07743 Jena, Germany
| | - Stephan C Bischoff
- Department of Nutritional Medicine, University of Hohenheim, Fruwirthstr. 12, 70599 Stuttgart, Germany.
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Regnault TRH, Gentili S, Sarr O, Toop CR, Sloboda DM. Fructose, pregnancy and later life impacts. Clin Exp Pharmacol Physiol 2013; 40:824-37. [DOI: 10.1111/1440-1681.12162] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 08/08/2013] [Accepted: 08/14/2013] [Indexed: 02/06/2023]
Affiliation(s)
- Timothy RH Regnault
- Department of Obstetrics and Gynaecology; Children's Health Research Institute; Western University; London ON Canada
| | - Sheridan Gentili
- School of Pharmacy and Medical Sciences; Sansom Institute for Health Research; University of South Australia; Adelaide SA Australia
| | - Ousseynou Sarr
- Department of Obstetrics and Gynaecology; Children's Health Research Institute; Western University; London ON Canada
| | - Carla R Toop
- School of Pharmacy and Medical Sciences; Sansom Institute for Health Research; University of South Australia; Adelaide SA Australia
| | - Deborah M Sloboda
- Department of Biochemistry and Biomedical Sciences; Faculty of Health Sciences; McMaster University; Hamilton ON Canada
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Abstract
Despite skeletal muscle being considered by many as the source of insulin resistance, physiology tells us that the liver is a central and cardinal regulator of glucose homeostasis. This is sometimes underestimated because, in contrast with muscle, investigations of liver function are technically very difficult. Nevertheless, recent experimental and clinical research has demonstrated clearly that, due in part to its anatomic position, the liver is exquisitely sensitive to insulin and other hormonal and neural factors, either by direct intrahepatic mechanisms or indirectly by organ cross-talk with muscle or adipose tissue. Because the liver receives absorbed nutrients, these have a direct impact on liver function, whether via a caloric excess or via the nature of food components (eg, fructose, many lipids, and trans fatty acids). An emerging observation with a possibly great future is the increase in intestinal permeability observed as a consequence of high fat intake or bacterial modifications in microbiota, whereby substances normally not crossing the gut gain access to the liver, where inflammation, oxidative stress, and lipid accumulation leads to fatty liver, a situation observed very early in the development of diabetes. The visceral adipose tissue located nearby is another main source of inflammatory substances and oxidative stress, and also acts on hepatocytes and Kupffer cells, resulting in stimulation of macrophages. Liberation of these substances, in particular triglycerides and inflammation factors, into the circulation leads to ectopic fat deposition and vascular damage. Therefore, the liver is directly involved in the development of the prediabetic cardiometabolic syndrome. Treatments are mainly metformin, and possibly statins and vitamin D. A very promising avenue is treatment of the leaky gut, which appears increasingly to be an important causal factor in hepatic insulin resistance and steatosis.
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Affiliation(s)
- Nicolas Wiernsperger
- INSERM French Institute of Health and Medical Research, U1060, National Institute of Applied Sciences, Lyon, University of Lyon, Villeurbanne, France
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126
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Scalera A, Di Minno MND, Tarantino G. What does irritable bowel syndrome share with non-alcoholic fatty liver disease? World J Gastroenterol 2013; 19:5402-5420. [PMID: 24023483 PMCID: PMC3761093 DOI: 10.3748/wjg.v19.i33.5402] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 07/25/2013] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) and irritable bowel syndrome (IBS) are two very common diseases in the general population. To date, there are no studies that highlight a direct link between NAFLD and IBS, but some recent reports have found an interesting correlation between obesity and IBS. A systematic PubMed database search was conducted highlighting that common mechanisms are involved in many of the local and systemic manifestations of NAFLD, leading to an increased cardiovascular risk, and IBS, leading to microbial dysbiosis, impaired intestinal barrier and altered intestinal motility. It is not known when considering local and systemic inflammation/immune system activation, which one has greater importance in NAFLD and IBS pathogenesis. Also, the nervous system is implicated. In fact, inflammation participates in the development of mood disorders, such as anxiety and depression, characteristics of obesity and consequently of NAFLD and, on the other hand, in intestinal hypersensitivity and dysmotility.
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Kavanagh K, Wylie AT, Tucker KL, Hamp TJ, Gharaibeh RZ, Fodor AA, Cullen JMC. Dietary fructose induces endotoxemia and hepatic injury in calorically controlled primates. Am J Clin Nutr 2013; 98:349-57. [PMID: 23783298 PMCID: PMC3712547 DOI: 10.3945/ajcn.112.057331] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Controversy exists regarding the causative role of dietary fructose in obesity and fatty liver diseases. Clinical trials have indicated that negative health consequences may occur only when fructose is consumed within excess calories. Animal studies have suggested that fructose impairs intestinal integrity and leads to hepatic steatosis (HS). OBJECTIVES We assessed nonhuman primates after chronic ad libitum and short-term calorically controlled consumption of a high-fructose (HFr), low-fat diet (24% of calories). Microbial translocation (MT), microbiome, and metabolic health indexes were evaluated. DESIGN Seventeen monkeys fed 0.3–7 y of an HFr ad libitum diet were compared with 10 monkeys fed a low-fructose, low-fat diet (control). Ten middle-aged, weight-stable, fructose-naive monkeys were stratified into HFr and control groups fed for 6 wk at caloric amounts required to maintain weight stability. Metabolic endpoints, feces, liver, small and large intestinal biopsies, and portal blood samples were collected. RESULTS Monkeys allowed ad libitum HFr developed HS in contrast to the control diet, and the extent of ectopic fat was related to the duration of feeding. Diabetes incidence also increased. Monkeys that consumed calorically controlled HFr showed significant increases in biomarkers of liver damage, endotoxemia, and MT indexes and a trend for greater hepatitis that was related to MT; however, HS did not develop. CONCLUSIONS Even in the absence of weight gain, fructose rapidly causes liver damage that we suggest is secondary to endotoxemia and MT. HS relates to the duration of fructose consumption and total calories consumed. These data support fructose inducing both MT and ectopic fat deposition in primates.
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Affiliation(s)
- Kylie Kavanagh
- Department of Pathology Section on Comparative Medicine and Lipid Sciences, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, NC 27127, USA.
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Vajro P, Paolella G, Fasano A. Microbiota and gut-liver axis: their influences on obesity and obesity-related liver disease. J Pediatr Gastroenterol Nutr 2013; 56:461-8. [PMID: 23287807 PMCID: PMC3637398 DOI: 10.1097/mpg.0b013e318284abb5] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A specific bacterial gut microbiota profile with increased extraction of energy has recently been associated with obesity, which has been shown to be a transmissible phenotype by microbiota transplantation. At the same time, there is now increasing evidence that gut microbiota plays a role in the development of hepatic steatosis and its progression to nonalcoholic steatohepatitis. This review summarizes well known and unexpected interacting factors leading to obesity and its related hepatic diseases, including intestinal mucosal permeability and its regulation, gut microbiota and translocation of its biological products, and gut-associated lymphoid tissue. These intestinal factors dictate also the balance between tolerance and immune response, which are critical for most of the complications in near and far organs or systems. We review novel mechanisms involving the development of gut permeability and adipose tissue plasticity, for example, the cross-talk between the gut microbiota, lipopolysaccharide, high-fat diet, and the endocannabinoid system tone, which have not been fully explored. Interactions between gut microbiota and other factors (eg, inflammasome deficiency) also are reviewed as emerging but far from being completely elucidated mechanisms influencing the onset of obesity and nonalcoholic fatty liver disease.
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Affiliation(s)
- Pietro Vajro
- Department of Medicine and Surgery, University of Salerno Medical School, Salerno, Italy.
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