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Kang S, Koh JM, Im DS. N-3 Polyunsaturated Fatty Acids Protect against Alcoholic Liver Steatosis by Activating FFA4 in Kupffer Cells. Int J Mol Sci 2024; 25:5476. [PMID: 38791514 PMCID: PMC11122576 DOI: 10.3390/ijms25105476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 05/11/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024] Open
Abstract
Supplementation with fish oil rich in omega-3 polyunsaturated fatty acids (n-3 PUFAs) effectively reduces acute and chronic alcohol-induced hepatic steatosis. We aimed to find molecular mechanisms underlying the effects of n-3 PUFAs in alcohol-induced hepatic steatosis. Because free fatty acid receptor 4 (FFA4, also known as GPR120) has been found as a receptor for n-3 PUFAs in an ethanol-induced liver steatosis model, we investigated whether n-3 PUFAs protect against liver steatosis via FFA4 using AH7614, an FFA4 antagonist, and Ffa4 knockout (KO) mice. N-3 PUFAs and compound A (CpdA), a selective FFA4 agonist, reduced the ethanol-induced increase in lipid accumulation in hepatocytes, triglyceride content, and serum ALT levels, which were not observed in Ffa4 KO mice. N-3 PUFAs and CpdA also reduced the ethanol-induced increase in lipogenic sterol regulatory element-binding protein-1c expression in an FFA4-dependent manner. In Kupffer cells, treatment with n-3 PUFA and CpdA reversed the ethanol-induced increase in tumor necrosis factor-α, cyclooxygenase-2, and NLR family pyrin domain-containing 3 expression levels in an FFA4-dependent manner. In summary, n-3 PUFAs protect against ethanol-induced hepatic steatosis via the anti-inflammatory actions of FFA4 on Kupffer cells. Our findings suggest FFA4 as a therapeutic target for alcoholic hepatic steatosis.
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Affiliation(s)
- Saeromi Kang
- Research Institute for Drug Development, Pusan National University, Busan 46241, Republic of Korea;
| | - Jung-Min Koh
- Division of Endocrinology and Metabolism, Asan Medical Center, College of Medicine, University of Ulsan, Seoul 05505, Republic of Korea;
| | - Dong-Soon Im
- Research Institute for Drug Development, Pusan National University, Busan 46241, Republic of Korea;
- Department of Basic Pharmaceutical Sciences, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
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2
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Graham DS, Liu G, Arasteh A, Yin XM, Yan S. Ability of high fat diet to induce liver pathology correlates with the level of linoleic acid and Vitamin E in the diet. PLoS One 2023; 18:e0286726. [PMID: 37267350 DOI: 10.1371/journal.pone.0286726] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 05/20/2023] [Indexed: 06/04/2023] Open
Abstract
Increased uptake of fat, such as through the ingestion of high fat diet (HFD), can lead to fatty liver diseases and metabolic syndrome. It is not clear whether certain fatty acids may be more pathogenic than others to the liver. Linoleic acid (LA) is the most abundant polyunsaturated fatty acid in the Western diet and its excessive consumption can lead to increased lipid peroxidation. We hypothesized that a high level of LA in HFD will contribute significantly to the hepatic steatosis and injury, whereas vitamin E (VIT-E) may reverse the effects from LA by inhibiting lipid peroxidation. To test this hypothesis, we fed mice with the following diets for 20 weeks: a standard low-fat diet (CHOW), HFD with a low level of LA (LOW-LA, 1% of energy from LA), HFD with a high level of LA (HI-LA, 8% of energy from LA), or HI-LA diet with VIT-E supplement (HI-LA + VIT-E). We found that the HI-LA diet resulted in more body weight gain, larger adipocyte area, and higher serum levels of triglycerides (TG) and free fatty acids (FFA) relative to the CHOW and LOW-LA diets. In mice fed with the HI-LA diet, severer hepatic steatosis was seen with higher levels of hepatic TG and FFA. Expression of genes related to lipid metabolism was altered in the liver by HI-LA diet, including fibroblast growth factor 21 (Fgf21), cluster of differentiation 36 (Cd36), stearoyl-CoA desaturase 1 (Scd1), and acyl-CoA oxidase 1 (Acox1). Liver injury, inflammation and fibrotic response were all enhanced in mice fed with the HI-LA diet when compared with the LOW-LA diet. Notably, addition of VIT-E supplement, which restores the proper VIT-E/PUFA ratio, significantly reduced the detrimental effects of the high level of LA. Taken together, our results suggest that a high level of LA and a low ratio of VIT-E/PUFA in HFD can contribute significantly to metabolic abnormalities and hepatic injury.
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Affiliation(s)
- Dalton S Graham
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Gang Liu
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Ailar Arasteh
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Xiao-Ming Yin
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Shengmin Yan
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
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3
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Ismaeel A, Laudato JA, Fletcher E, Papoutsi E, Tice A, Hwa LS, Miserlis D, Jamurtas AZ, Steiner J, Koutakis P. High-Fat Diet Augments the Effect of Alcohol on Skeletal Muscle Mitochondrial Dysfunction in Mice. Nutrients 2022; 14:1016. [PMID: 35267991 PMCID: PMC8912391 DOI: 10.3390/nu14051016] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 11/16/2022] Open
Abstract
Previous studies have shown that chronic heavy alcohol consumption and consumption of a high-fat (HF) diet can independently contribute to skeletal muscle oxidative stress and mitochondrial dysfunction, yet the concurrent effect of these risk factors remains unclear. We aimed to assess the effect of alcohol and different dietary compositions on mitochondrial activity and oxidative stress markers. Male and female mice were randomized to an alcohol (EtOH)-free HF diet, a HF + EtOH diet, or a low-Fat (LF) + EtOH diet for 6 weeks. At the end of the study, electron transport chain complex activity and expression as well as antioxidant activity and expression, were measured in skeletal muscles. Complex I and III activity were diminished in muscles of mice fed a HF + EtOH diet relative to the EtOH-free HF diet. Lipid peroxidation was elevated, and antioxidant activity was diminished, in muscles of mice fed a HF + EtOH diet as well. Consumption of a HF diet may exacerbate the negative effects of alcohol on skeletal muscle mitochondrial health and oxidative stress.
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Affiliation(s)
- Ahmed Ismaeel
- Department of Biology, Baylor University, Waco, TX 76798, USA; (A.I.); (E.F.); (E.P.)
| | - Joseph A. Laudato
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL 32304, USA; (J.A.L.); (A.T.); (J.S.)
| | - Emma Fletcher
- Department of Biology, Baylor University, Waco, TX 76798, USA; (A.I.); (E.F.); (E.P.)
| | - Evlampia Papoutsi
- Department of Biology, Baylor University, Waco, TX 76798, USA; (A.I.); (E.F.); (E.P.)
| | - Abigail Tice
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL 32304, USA; (J.A.L.); (A.T.); (J.S.)
| | - Lara S. Hwa
- Department of Psychology and Neuroscience, Baylor University, Waco, TX 76798, USA;
| | - Dimitrios Miserlis
- Department of Surgery, University of Texas Health Science Center San Antonio, San Antonio, TX 78229, USA;
| | - Athanasios Z. Jamurtas
- Department of Physical Education and Sport Sciences, University of Thessaly, 42100 Trikala, Greece;
- Department of Nutrition and Dietetics, University of Thessaly, 42100 Trikala, Greece
| | - Jennifer Steiner
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL 32304, USA; (J.A.L.); (A.T.); (J.S.)
| | - Panagiotis Koutakis
- Department of Biology, Baylor University, Waco, TX 76798, USA; (A.I.); (E.F.); (E.P.)
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4
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Yang SC. A New Perspective on Fish Oil: The Prevention of Alcoholic Liver Disease. J Oleo Sci 2021; 70:1531-1538. [PMID: 34732632 DOI: 10.5650/jos.ess21216] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The mechanisms of alcoholic liver diseases (ALD) are very complex and interrelated, including abnormal lipid metabolism, oxidative stress, and gut-derived endotoxin pathway. On the other hand, fish oil is rich in n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which decrease blood triglyceride concentration in hypertriglycemia patients and show protective effects against fatty liver. However, there is limited evidence from studies of the relationship between fish oil and ALD based on the viewpoint of the intestinal integrity and microflora. Therefore, this review discusses the mechanism of amelioration for ALD by fish oil. Based on our previous studies, partial replacement of olive oil by fish oil in alcohol-containing liquid diet ameliorated the liver damage including fatty liver and inflammation in rats. Based on these results, the mechanisms of hepatoprotective effects due to fish oil substitution were discussed in three parts, such as regulating lipid metabolism, decreasing oxidative stress and maintaining intestinal health. First of all, we found that fish oil substitution increased plasma adiponectin levels, and then increasing MCAD and CPT-1 mRNA levels to accelerate fatty acid oxidation in liver, then further prevent ethanol-induced hepatosteatosis in rats with chronic alcohol-feeding. Fish oil replacement also enhanced hepatic autophagy flux, which enhanced lipid degradation, then inhibited lipid accumulation in liver. Secondly, the appreciable proportion of fish oil decreased lipid peroxidation by reducing the protein expression of cytochrome p450 2E1 in chronic alcohol-feeding rats. We also speculated that the appropriate proportion of n-6 and n-3 PUFAs is very important for preventing alcoholic liver disease. At last, substituting fish oil for olive oil normalized the intestinal permeability and fecal microbiota composition, thus providing a low plasma endotoxin level and inflammatory responses, which exert ameliorative effects on ethanol-induced liver injuries in rats.
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Affiliation(s)
- Suh-Ching Yang
- School of Nutrition and Health Sciences, Taipei Medical University.,Research Center of Geriatric Nutrition, College of Nutrition, Taipei Medical University.,Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University.,School of Gerontology Health Management, College of Nursing, Taipei Medical University.,Nutrition Research Center, Taipei Medical University Hospital
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5
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Feng R, Ma LJ, Wang M, Liu C, Yang R, Su H, Yang Y, Wan JB. Oxidation of fish oil exacerbates alcoholic liver disease by enhancing intestinal dysbiosis in mice. Commun Biol 2020; 3:481. [PMID: 32879433 PMCID: PMC7468239 DOI: 10.1038/s42003-020-01213-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 08/04/2020] [Indexed: 02/06/2023] Open
Abstract
The role of n-3 polyunsaturated fatty acids (PUFAs) in alcoholic liver disease (ALD) has been controversial. N-3 PUFA oxidation in animal feeding stuffs was rarely concerned, likely contributing to inconsistent outcomes. Here, we report the impacts of oxidized fish oil (OFO) on ALD in C57BL/6 mice. Alcohol exposure increased plasma aminotransferase levels and hepatic inflammation. These deleterious effects were ameliorated by unoxidized FO but exacerbated by OFO. Sequencing analysis showed the accentuated intestinal dysbiosis and the increased proportion of Proteobacteria in OFO-fed mice. Intestinal sterilization by antibiotics completely abolished OFO-aggravated liver injury. Additionally, alcohol exposure leads to the greater increase in plasma endotoxin and decrease in intestinal tight junction protein expressions in OFO-fed mice. Stabilization of intestinal barrier by obeticholic acid markedly blunted OFO-aggravated liver injury in alcohol-fed mice. These results demonstrate that OFO exacerbates alcoholic liver injury through enhancing intestinal dysbiosis, barrier dysfunction, and hepatic inflammation mediated by gut-derived endotoxin. Feng et al. show that oxidized fish oil exacerbates alcoholic liver injury in mice by enhancing intestinal dysbiosis, barrier dysfunction, and hepatic inflammation that is mediated by gut-derived endotoxin. This study suggests that n-3 polyunsaturated fatty acids enriched in fish oil should be kept from oxidation to exert their health benefits.
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Affiliation(s)
- Ruibing Feng
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.,Key Laboratory of Tropical Biological Resources of Ministry of Education, Key Laboratory for Marine Drugs of Haikou, School of Life and Pharmaceutical Sciences, Hainan University, Haikou, 570228, China
| | - Li-Juan Ma
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Meng Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.,Center for Drug Innovation and Discovery, College of Life Science, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Conghui Liu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Rujie Yang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Huanxing Su
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Yan Yang
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Jian-Bo Wan
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
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6
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Jeon S, Carr R. Alcohol effects on hepatic lipid metabolism. J Lipid Res 2020; 61:470-479. [PMID: 32029510 DOI: 10.1194/jlr.r119000547] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/28/2020] [Indexed: 12/16/2022] Open
Abstract
Alcoholic liver disease (ALD) is the most prevalent type of chronic liver disease with significant morbidity and mortality worldwide. ALD begins with simple hepatic steatosis and progresses to alcoholic steatohepatitis, fibrosis, and cirrhosis. The severity of hepatic steatosis is highly associated with the development of later stages of ALD. This review explores the disturbances of alcohol-induced hepatic lipid metabolism through altered hepatic lipid uptake, de novo lipid synthesis, fatty acid oxidation, hepatic lipid export, and lipid droplet formation and catabolism. In addition, we review emerging data on the contributions of genetics and bioactive lipid metabolism in alcohol-induced hepatic lipid accumulation.
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Affiliation(s)
- Sookyoung Jeon
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
| | - Rotonya Carr
- Division of Gastroenterology, University of Pennsylvania, Philadelphia, PA
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7
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Fish oil up-regulates hepatic autophagy in rats with chronic ethanol consumption. J Nutr Biochem 2019; 77:108314. [PMID: 31884243 DOI: 10.1016/j.jnutbio.2019.108314] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/12/2019] [Accepted: 11/27/2019] [Indexed: 12/12/2022]
Abstract
In this study, we examined the regulation of autophagy by fish oil in rats under ethanol-containing diets. Thirty male Wistar rats (8-week-old) were divided into six groups and fed a control diet or an ethanol-containing diet, which was adjusted with fish oil to replace 25% or 57% of the olive oil. After 8 weeks, rats in the E (ethanol diet) group showed the significantly higher plasma aspartate transaminase (AST) and alanine transaminase (ALT) activities, protein expression of cytochrome P450 2E1 (CYP2E1), and levels of hepatic inflammatory cytokines. However, all of those items had significantly decreased in the EF25 (ethanol with 25% fish oil) and EF57 (ethanol with 57% fish oil) groups. As to autophagic indicators, protein expressions of mammalian target of rapamycin (mTOR), Unc-51-like autophagy activating kinase 1 (ULK1) and p62 were significantly increased in the E group. Conversely, the protein expressions of light chain 3II (LC3II)/LC3I and Beclin1 were significantly decreased in the E group. On the other hand, protein expressions of phosphorylated Akt, mTOR, ULK1, and p62 were down-regulated, protein expressions of LC3II/LC3I and Beclin1 were conversely up-regulated in the EF25 and EF57 groups. Fish oil activated hepatic autophagy via inhibiting the Akt signaling pathway, which exerted protective effects against ethanol-induced liver injury in rats.
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8
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Wang M, Ma LJ, Yang Y, Xiao Z, Wan JB. n-3 Polyunsaturated fatty acids for the management of alcoholic liver disease: A critical review. Crit Rev Food Sci Nutr 2018; 59:S116-S129. [PMID: 30580553 DOI: 10.1080/10408398.2018.1544542] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Excess alcohol exposure leads to alcoholic liver disease (ALD), a predominant cause of liver-related morbidity and mortality worldwide. In the past decade, increasing attention has been paid to understand the association between n-3 polyunsaturated fatty acids (n-3 PUFAs) and ALD. In this review, we summarize the metabolism of n-3 PUFAs, animal model of ALD, and the findings from recent studies determining the role of n-3 PUFAs in ALD as a possible treatment. The animal models of acute ethanol exposure, chronic ethanol exposure and chronic-plus-single binge ethanol feeding have been widely used to explore the impact of n-3 PUFAs. Although the results of studies regarding the role of n-3 PUFAs in ALD have been inconsistent or controversial, increasing evidence has demonstrated that n-3 PUFAs may be useful in alleviating alcoholic steatosis and alcohol-induced liver injury through multiple mechanisms, including decreased de novo lipogenesis and lipid mobilization from adipose tissue, enhanced mitochondrial fatty acid β-oxidation, reduced hepatic inflammation and oxidative stress, and promoted intestinal homeostasis, positively suggesting that n-3 PUFAs might be promising for the management of ALD. The oxidation of n-3 PUFAs ex vivo in an experimental diet was rarely considered in most n-3 PUFA-related studies, likely contributing to the inconsistent results. Thus, the role of n-3 PUFAs in ALD deserves greater research efforts and remains to be evaluated in randomized, placebo-controlled clinic trial. ABBREVIATION AA arachidonic acid ACC acetyl-CoA carboxylase ACLY ATP-citrate lyase ACO acyl-CoA oxidase ALA α-linolenic acid ALD alcoholic liver disease ALP alkaline phosphatase ALT alanine aminotransferase AMPK AMP-activated protein kinase AST aspartate aminotransferase ATGL adipose triglyceride lipase cAMP cyclic adenosine 3',5'-monophosphate COX cyclooxygenases CPT1 carnitine palmitoyltransferase 1 CYP2E1 cytochrome P450 2E1 DGAT2 diacylglycerol acyltransferase 2 DGLA dihomo-γ-linolenic acid DHA docosahexaenoic acid DPA docosapentaenoic acid DTA docosatetraenoic acid EPA eicosapentaenoic acid ER endoplasmic reticulum ETA eicosatetraenoic acid FAS fatty acid synthase FATPs fatty acid transporter proteins GLA,γ linolenic acid GPR120 G protein-coupled receptor 120 GSH glutathione; H&E haematoxylin-eosin; HO-1 heme oxygenase-1; HSL hormone-sensitive lipase; IL-6 interleukin-6 iNOS nitric oxide synthase LA linoleic acid LBP lipopolysaccharide binding protein LOX lipoxygenases LXR liver X receptor LXREs LXR response elements MCP-1 monocyte chemotactic protein-1 MTP microsomal triglyceride transfer protein MUFA monounsaturated fatty acids MyD88 myeloid differentiation factor 88 n-3 PUFAs omega-3 polyunsaturated fatty acid NAFLD nonalcoholic fatty liver disease NASH nonalcoholic steatohepatitis NF-κB transcription factor nuclear factor κB PDE3B phosphodiesterase 3B PPAR peroxisome proliferator-activated receptor ROS reactive oxygen species RXR retinoid X receptor SCD-1 stearyl CoA desaturase-1 SDA stearidonic acid SFA saturated fatty acids SIRT1 sirtuin 1 SOD superoxide dismutase SREBP sterol regulatory element-binding protein TB total bilirubin TC total cholesterol TG triacylglycerol TLR4 Toll-like receptor-4 TNF-α tumor necrosis factor-α VLDLR very low-density lipoprotein receptor WT wild type; ZO-1 zonula occludens-1.
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Affiliation(s)
- Meng Wang
- a State Key Laboratory of Quality Research in Chinese Medicine , Institute of Chinese Medical Sciences, University of Macau , Macao , China.,b Center for Drug Innovation and Discovery, College of Life Science, Hebei Normal University , Shijiazhuang , Hebei , China
| | - Li-Juan Ma
- a State Key Laboratory of Quality Research in Chinese Medicine , Institute of Chinese Medical Sciences, University of Macau , Macao , China
| | - Yan Yang
- c Department of Nutrition, School of Public Health , Sun Yat-Sen University , Guangzhou , China
| | - Zeyu Xiao
- d Collaborative Translational Medicine Collaborative Innovation Center, Department of Pharmacology and Chemical Biology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jian-Bo Wan
- a State Key Laboratory of Quality Research in Chinese Medicine , Institute of Chinese Medical Sciences, University of Macau , Macao , China
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9
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Ethanol and C2 ceramide activate fatty acid oxidation in human hepatoma cells. Sci Rep 2018; 8:12923. [PMID: 30150688 PMCID: PMC6110824 DOI: 10.1038/s41598-018-31025-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 08/04/2018] [Indexed: 02/07/2023] Open
Abstract
Obesogenic lipids and the sphingolipid ceramide have been implicated as potential cofactors in alcoholic liver disease (ALD) patients. However, the mechanisms by which these lipids modulate lipid trafficking in ethanol-treated human liver cells to promote steatosis, an early stage of ALD, are poorly understood. We measured fatty acid (FA) uptake, triglyceride export, FA synthesis and FA oxidation in human hepatoma (VL-17A) cells in response to ethanol and the exogenous lipids oleate, palmitate and C2 ceramide. We found that in combination with ethanol, both oleate and palmitate promote lipid droplet accumulation while C2 ceramide inhibits lipid droplet accumulation by enhancing FA oxidation. Further, using both a pharmacologic and siRNA approach to reduce peroxisome proliferator-activated receptors α (PPARα) gene expression, we demonstrate that C2 ceramide abrogates ethanol-mediated suppression of FA oxidation through an indirect PPARα mechanism. Together, these data suggest that lipids interact differentially with ethanol to modulate hepatocellular lipid droplet accumulation and may provide novel targets for preventing the earliest stage of alcoholic liver disease, alcoholic steatosis.
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10
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Wang HY, Peng HC, Chien YW, Chen YL, Lu NS, Yang SC. Effects of Fish Oil on Lipid Metabolism and Its Molecular Biological Regulators in Chronic Ethanol-Fed Rats. Nutrients 2018; 10:E802. [PMID: 29932129 PMCID: PMC6073669 DOI: 10.3390/nu10070802] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 06/14/2018] [Accepted: 06/20/2018] [Indexed: 02/07/2023] Open
Abstract
The purpose of this study was to clarify the hepatoprotective mechanisms of fish oil in ethanol-fed rats based on lipid metabolism. Thirty eight-week-old male Wistar rats were divided into six groups: C (control), CF25 (control diet with 25% fish oil substitution), CF57 (control diet with 57% fish oil substitution), E (ethanol-containing diet) group, EF25 (ethanol-containing diet with 25% fish oil substitution), and EF57 (ethanol-containing diet with 57% fish oil substitution) groups. All of the groups were pair-fed an isoenergetic diet based on E group. Rats were sacrificed after eight weeks. When compared with C group, the plasma aspartate transaminase (AST) activity and hepatic steatosis and inflammatory cell infiltration were significantly higher, while plasma adiponectin level and hepatic AMP-activated protein kinase α (AMPKα) protein expression was significantly lower in the E group. However, the hepatic damage, including steatosis and inflammation were ameliorated in the EF25 and EF57 groups. Moreover, mRNA levels of fatty acid-oxidative enzymes, such as medium-chain acyl-coenzyme A dehydrogenase (MCAD) and carnitine palmitoyltransferase I (CPT-1) were significantly elevated in the EF57 group than those in E group. Partial replacement with fish oil might improve the fatty acid oxidation by raising mRNA levels of downstream transcription factors, finally inhibit the ethanol-induced hepatic steatosis in rats.
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Affiliation(s)
- Hsiao-Yun Wang
- School of Nutrition and Health Sciences, Taipei Medical University, Taipei 11031, Taiwan.
| | - Hsiang-Chi Peng
- School of Nutrition and Health Sciences, Taipei Medical University, Taipei 11031, Taiwan.
- Research Center of Geriatric Nutrition, College of Nutrition, Taipei Medical University, Taipei 11031, Taiwan.
| | - Yi-Wen Chien
- School of Nutrition and Health Sciences, Taipei Medical University, Taipei 11031, Taiwan.
- Research Center of Geriatric Nutrition, College of Nutrition, Taipei Medical University, Taipei 11031, Taiwan.
- Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University, Taipei 11031, Taiwan.
| | - Ya-Ling Chen
- Department of Nutrition and Health Sciences, Chang Gung University of Science and Technology, Taoyuan 33303, Taiwan.
| | - Nien-Shan Lu
- School of Nutrition and Health Sciences, Taipei Medical University, Taipei 11031, Taiwan.
| | - Suh-Ching Yang
- School of Nutrition and Health Sciences, Taipei Medical University, Taipei 11031, Taiwan.
- Research Center of Geriatric Nutrition, College of Nutrition, Taipei Medical University, Taipei 11031, Taiwan.
- Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University, Taipei 11031, Taiwan.
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11
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Ely PH. Is psoriasis a bowel disease? Successful treatment with bile acids and bioflavonoids suggests it is. Clin Dermatol 2018; 36:376-389. [PMID: 29908580 DOI: 10.1016/j.clindermatol.2018.03.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The gut is the largest lymphoid organ in the body. The human microbiome is composed of trillions of bacteria. The DNA of these bacteria dwarfs the human genome. Diet and ethanol can cause rapid shifts in the number and types of bacteria in the gut. The psoriatic microbiome is similar to that seen in alcoholics; there is a decrease in bacterial diversity and overgrowth of bacteria in the small bowel. Psoriatics often have liver disease and deficiencies in bile acids. Psoriasis is a disease characterized by a leaky gut. All of the comorbidities of this disease are due to systemic endotoxemia. Bacterial peptidoglycans absorbed from the gut have direct toxic effects on the liver and skin. Their absorption, as well as endotoxin absorption, must be eliminated to treat psoriasis successfully. Endotoxin absorption is markedly increased by ethanol and peppers. Bioflavonoids, such as quercetin and citrus bioflavonoids, prevent this absorption. Bile acids, given orally, break up endotoxin in the intestinal lumen. Pathogens, including Helicobacter pylori and Streptococcus pyogenes, must be eliminated with antimicrobial therapy for any treatment to work. A complete protocol for curing psoriasis is provided.
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Affiliation(s)
- P Haines Ely
- VA North California Health Care System, Mather, CA; University of California Davis School of Medicine, Sacramento, CA; Department of Dermatology, Sacramento VA Medical Center, Mather, CA.
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12
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Yao Y, Zhang P, Wang J, Chen J, Wang Y, Huang Y, Zhang Z, Xu F. Dissecting Target Toxic Tissue and Tissue Specific Responses of Irinotecan in Rats Using Metabolomics Approach. Front Pharmacol 2017; 8:122. [PMID: 28344557 PMCID: PMC5344918 DOI: 10.3389/fphar.2017.00122] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 02/27/2017] [Indexed: 12/26/2022] Open
Abstract
As an anticancer agent, irinotecan (CPT-11) has been widely applied in clinical, especially in the treatment of colorectal cancer. However, its clinical use has long been limited by the side effects and potential tissue toxicity. To discriminate the target toxic tissues and dissect the specific response of target tissues after CPT-11 administration in rats, untargeted metabolomic study was conducted. First, differential metabolites between CPT-11 treated group and control group in each tissue were screened out. Then, based on fold changes of these differential metabolites, principal component analysis and hierarchical cluster analysis were performed to visualize the degree and specificity of the influences of CPT-11 on the metabolic profiles of nine tissues. Using this step-wise method, ileum, jejunum, and liver were finally recognized as target toxic tissues. Furthermore, tissue specific responses of liver, ileum, and jejunum to CPT-11 were dissected and specific differential metabolites were screened out. Perturbations in Krebs cycle, amino acid, purine and bile acid metabolism were observed in target toxic tissues. In conclusion, our study put forward a new approach to dissect target toxic tissues and tissue specific responses of CPT-11 using metabolomics.
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Affiliation(s)
- Yiran Yao
- Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical UniversityNanjing, China; Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical UniversityNanjing, China; State Key Laboratory of Natural Medicine, China Pharmaceutical UniversityNanjing, China
| | - Pei Zhang
- Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical UniversityNanjing, China; Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical UniversityNanjing, China; State Key Laboratory of Natural Medicine, China Pharmaceutical UniversityNanjing, China
| | - Jing Wang
- School of Pharmacy, Shanxi University of Chinese Medicine Xianyang, China
| | - Jiaqing Chen
- Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical UniversityNanjing, China; Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical UniversityNanjing, China; State Key Laboratory of Natural Medicine, China Pharmaceutical UniversityNanjing, China
| | - Yong Wang
- Jiangsu Institute for Food and Drug Control Nanjing, China
| | - Yin Huang
- Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical UniversityNanjing, China; Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical UniversityNanjing, China; State Key Laboratory of Natural Medicine, China Pharmaceutical UniversityNanjing, China
| | - Zunjian Zhang
- Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical UniversityNanjing, China; Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical UniversityNanjing, China; State Key Laboratory of Natural Medicine, China Pharmaceutical UniversityNanjing, China
| | - Fengguo Xu
- Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical UniversityNanjing, China; Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical UniversityNanjing, China; State Key Laboratory of Natural Medicine, China Pharmaceutical UniversityNanjing, China
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Low- ω3 Fatty Acid and Soy Protein Attenuate Alcohol-Induced Fatty Liver and Injury by Regulating the Opposing Lipid Oxidation and Lipogenic Signaling Pathways. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:1840513. [PMID: 28074114 PMCID: PMC5203909 DOI: 10.1155/2016/1840513] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/14/2016] [Accepted: 11/15/2016] [Indexed: 12/20/2022]
Abstract
Chronic ethanol-induced downregulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) and upregulation of peroxisome proliferator-activated receptor gamma coactivator 1-beta (PGC1β) affect hepatic lipid oxidation and lipogenesis, respectively, leading to fatty liver injury. Low-ω3 fatty acid (Low-ω3FA) that primarily regulates PGC1α and soy protein (SP) that seems to have its major regulatory effect on PGC1β were evaluated for their protective effects against ethanol-induced hepatosteatosis in rats fed with Lieber-deCarli control or ethanol liquid diets with high or low ω3FA fish oil and soy protein. Low-ω3FA and SP opposed the actions of chronic ethanol by reducing serum and liver lipids with concomitant decreased fatty liver. They also prevented the downregulation of hepatic Sirtuin 1 (SIRT1) and PGC1α and their target fatty acid oxidation pathway genes and attenuated the upregulation of hepatic PGC1β and sterol regulatory element-binding protein 1c (SREBP1c) and their target lipogenic pathway genes via the phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK). Thus, these two novel modulators attenuate ethanol-induced hepatosteatosis and consequent liver injury potentially by regulating the two opposing lipid oxidation and lipogenic pathways.
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Anders LC, Yeo H, Kaelin BR, Lang AL, Bushau AM, Douglas AN, Cave M, Arteel GE, McClain CJ, Beier JI. Role of dietary fatty acids in liver injury caused by vinyl chloride metabolites in mice. Toxicol Appl Pharmacol 2016; 311:34-41. [PMID: 27693805 PMCID: PMC5079761 DOI: 10.1016/j.taap.2016.09.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 09/24/2016] [Accepted: 09/27/2016] [Indexed: 02/09/2023]
Abstract
BACKGROUND Vinyl chloride (VC) causes toxicant-associated steatohepatitis at high exposure levels. Recent work by this group suggests that underlying liver disease may predispose the liver to VC hepatotoxicity at lower exposure levels. The most common form of underlying liver disease in the developed world is non-alcoholic fatty liver disease (NAFLD). It is well-known that the type of dietary fat can play an important role in the pathogenesis of NAFLD. However, whether the combination of dietary fat and VC/metabolites promotes liver injury has not been studied. METHODS Mice were administered chloroethanol (CE - a VC metabolite) or vehicle once, 10weeks after being fed diets rich in saturated fatty acids (HSFA), rich in poly-unsaturated fatty acids (HPUFA), or the respective low-fat control diets (LSFA; LPUFA). RESULTS In control mice, chloroethanol caused no detectable liver injury, as determined by plasma transaminases and histologic indices of damage. In HSFA-fed mice, chloroethanol increased HSFA-induced liver damage, steatosis, infiltrating inflammatory cells, hepatic expression of proinflammatory cytokines, and markers of endoplasmic reticulum (ER) stress. Moreover, markers of inflammasome activation were increased, while markers of inflammasome inhibition were downregulated. In mice fed HPUFA all of these effects were significantly attenuated. CONCLUSIONS Chloroethanol promotes inflammatory liver injury caused by dietary fatty acids. This effect is far more exacerbated with saturated fat, versus poly-unsaturated fat; and strongly correlates with a robust activation of the NLRP3 inflammasome in the saturated fed animals only. Taken together these data support the hypothesis that environmental toxicant exposure can exacerbate the severity of NAFLD/NASH.
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Affiliation(s)
- Lisanne C Anders
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Heegook Yeo
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Brenna R Kaelin
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Anna L Lang
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Adrienne M Bushau
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Amanda N Douglas
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Matt Cave
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Diabetes and Obesity Center, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Robley Rex Louisville VAMC, Louisville, KY 40206, USA
| | - Gavin E Arteel
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Craig J McClain
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Department of Medicine, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Diabetes and Obesity Center, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Robley Rex Louisville VAMC, Louisville, KY 40206, USA
| | - Juliane I Beier
- Department of Pharmacology and Toxicology, University of Louisville Health Sciences Center, Louisville, KY 40292, USA; Hepatobiology and Toxicology Program, University of Louisville Health Sciences Center, Louisville, KY 40292, USA.
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15
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Hartmann P, Seebauer CT, Schnabl B. Alcoholic liver disease: the gut microbiome and liver cross talk. Alcohol Clin Exp Res 2016; 39:763-75. [PMID: 25872593 DOI: 10.1111/acer.12704] [Citation(s) in RCA: 175] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 02/18/2015] [Indexed: 01/18/2023]
Abstract
Alcoholic liver disease (ALD) is a leading cause of morbidity and mortality worldwide. Alcoholic fatty liver disease can progress to steatohepatitis, alcoholic hepatitis, fibrosis, and cirrhosis. Patients with alcohol abuse show quantitative and qualitative changes in the composition of the intestinal microbiome. Furthermore, patients with ALD have increased intestinal permeability and elevated systemic levels of gut-derived microbial products. Maintaining eubiosis, stabilizing the mucosal gut barrier, or preventing cellular responses to microbial products protect from experimental ALD. Therefore, intestinal dysbiosis and pathological bacterial translocation appear fundamental for the pathogenesis of ALD. This review highlights causes for intestinal dysbiosis and pathological bacterial translocation, their relationship, and consequences for ALD. We also discuss how the liver affects the intestinal microbiota.
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Affiliation(s)
- Phillipp Hartmann
- Department of Medicine, University of California, San Diego, La Jolla, California
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Chen YL, Peng HC, Wang XD, Yang SC. Dietary saturated fatty acids reduce hepatic lipid accumulation but induce fibrotic change in alcohol-fed rats. Hepatobiliary Surg Nutr 2015; 4:172-83. [PMID: 26151057 DOI: 10.3978/j.issn.2304-3881.2015.01.04] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 12/09/2014] [Indexed: 12/20/2022]
Abstract
BACKGROUND In this study, we evaluated the influence of an ethanol-containing diet with high saturated fatty acids (SFAs) on alcoholic liver disease (ALD) in rats. METHODS Male Wistar rats weighing about 160 g were divided into four groups: an ethanol (E) group fed an ethanol-containing liquid diet with 36% total calories as fat (corn oil, olive oil and safflower oil); a control (C) group pair-fed an isoenergetic diet without ethanol; an ethanol with saturated fat (EHS) group fed an ethanol-containing diet which contained 40% total calories as fat (90% lard); and a control with saturated fat (CHS) group fed an isoenergetic diet without ethanol, which contained 40% total calories as fat. RESULTS After 8 weeks of treatment, the liver weight and plasma aspartate aminotransferase (AST) activities in E and EHS groups were significantly higher than those of C group. Significantly higher scores of inflammation, necrosis, and fatty changes were found in E group, whereas significantly higher scores of necrosis, bile duct hyperplasia, and fibrosis were found in EHS group. Although significantly lower plasma adiponectin concentrations were observed in both E and EHS groups, compared to C group, plasma adiponectin in EHS group was significantly higher than that in E group. There was no change in hepatic peroxisome proliferator activated receptor (PPAR)-α expression between E and C groups, and rats in EHS group showed a significantly elevated level compared to the other groups. A lower hepatic sirtuins (SIRT)-1 level was found in E group, but it did not reach statistical significance. Moreover, the highest plasma TGF-β1 level was found in EHS group. Compared to C group, the hepatic reduced glutathione/oxidized glutathione ratio and thiobarbituric acid (TBA)-reactive substance level were significantly increased in E and EHS groups; however, there was no significant difference between E and EHS groups. Significantly increased hepatic CYP2E1 expression was observed in both E and EHS groups, while at the same time, hepatic CYP2E1 in EHS group was the highest among all groups. The hepatic tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 concentrations in the E group were significantly higher than those in C group, whereas the hepatic IL-6 and IL-10 concentrations in ES group were significantly lower than those of E group. CONCLUSIONS These results suggested that dietary saturated fats may inhibit hepatic fat accumulation and induce hepatic fibrosis in rats under chronic alcohol intake.
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Affiliation(s)
- Ya-Ling Chen
- 1 School of Nutrition and Health Sciences, Taipei Medical University, Taipei 110, Taiwan ; 2 Nutrition and Cancer Biology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111-1524, USA
| | - Hsiang-Chi Peng
- 1 School of Nutrition and Health Sciences, Taipei Medical University, Taipei 110, Taiwan ; 2 Nutrition and Cancer Biology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111-1524, USA
| | - Xiang-Dong Wang
- 1 School of Nutrition and Health Sciences, Taipei Medical University, Taipei 110, Taiwan ; 2 Nutrition and Cancer Biology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111-1524, USA
| | - Suh-Ching Yang
- 1 School of Nutrition and Health Sciences, Taipei Medical University, Taipei 110, Taiwan ; 2 Nutrition and Cancer Biology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111-1524, USA
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Chen P, Torralba M, Tan J, Embree M, Zengler K, Stärkel P, van Pijkeren JP, DePew J, Loomba R, Ho SB, Bajaj JS, Mutlu EA, Keshavarzian A, Tsukamoto H, Nelson KE, Fouts DE, Schnabl B. Supplementation of saturated long-chain fatty acids maintains intestinal eubiosis and reduces ethanol-induced liver injury in mice. Gastroenterology 2015; 148:203-214.e16. [PMID: 25239591 PMCID: PMC4274236 DOI: 10.1053/j.gastro.2014.09.014] [Citation(s) in RCA: 214] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 08/08/2014] [Accepted: 09/11/2014] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Alcoholic liver disease is a leading cause of mortality. Chronic alcohol consumption is accompanied by intestinal dysbiosis, and development of alcoholic liver disease requires gut-derived bacterial products. However, little is known about how alterations to the microbiome contribute to pathogenesis of alcoholic liver disease. METHODS We used the Tsukamoto-French mouse model, which involves continuous intragastric feeding of isocaloric diet or alcohol for 3 weeks. Bacterial DNA from the cecum was extracted for deep metagenomic sequencing. Targeted metabolomics assessed concentrations of saturated fatty acids in cecal contents. To maintain intestinal metabolic homeostasis, diets of ethanol-fed and control mice were supplemented with saturated long-chain fatty acids (LCFA). Bacterial genes involved in fatty acid biosynthesis, amounts of lactobacilli, and saturated LCFA were measured in fecal samples of nonalcoholic individuals and patients with active alcohol abuse. RESULTS Analyses of intestinal contents from mice revealed alcohol-associated changes to the intestinal metagenome and metabolome, characterized by reduced synthesis of saturated LCFA. Maintaining intestinal levels of saturated fatty acids in mice resulted in eubiosis, stabilized the intestinal gut barrier, and reduced ethanol-induced liver injury. Saturated LCFA are metabolized by commensal Lactobacillus and promote their growth. Proportions of bacterial genes involved in fatty acid biosynthesis were lower in feces from patients with active alcohol abuse than controls. Total levels of LCFA correlated with those of lactobacilli in fecal samples from patients with active alcohol abuse but not in controls. CONCLUSIONS In humans and mice, alcohol causes intestinal dysbiosis, reducing the capacity of the microbiome to synthesize saturated LCFA and the proportion of Lactobacillus species. Dietary approaches to restore levels of saturated fatty acids in the intestine might reduce ethanol-induced liver injury in patients with alcoholic liver disease.
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Affiliation(s)
- Peng Chen
- Department of Medicine, University of California San Diego, La Jolla, CA
| | | | - Justin Tan
- Department of Bioengineering, University of California San Diego, La Jolla, CA
| | - Mallory Embree
- Department of Bioengineering, University of California San Diego, La Jolla, CA
| | - Karsten Zengler
- Department of Bioengineering, University of California San Diego, La Jolla, CA
| | - Peter Stärkel
- St. Luc University Hospital, Université Catholique de Louvain, Brussels, Belgium
| | | | | | - Rohit Loomba
- Department of Medicine, University of California San Diego, La Jolla, CA
| | - Samuel B. Ho
- Department of Medicine, University of California San Diego, La Jolla, CA,Department of Medicine, VA San Diego Healthcare System, San Diego, CA
| | - Jasmohan S. Bajaj
- Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University and McGuire VA Medical Center, Richmond, VA
| | - Ece A. Mutlu
- Department of Medicine, Rush University Medical Center, Chicago, IL
| | - Ali Keshavarzian
- Department of Medicine, Rush University Medical Center, Chicago, IL
| | - Hidekazu Tsukamoto
- Southern California Research Center for Alcoholic Liver and Pancreatic Diseases and Cirrhosis, Department of Pathology, Keck School of Medicine of the University of Southern California, Greater Los Angeles VA Healthcare System, Los Angeles, CA
| | | | | | - Bernd Schnabl
- Department of Medicine, University of California San Diego, La Jolla, California.
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Tilg H, Gao B. Dietary saturated lipids in alcoholic liver disease: new microbiota-targeting bullets? Gastroenterology 2015; 148:16-9. [PMID: 25451649 DOI: 10.1053/j.gastro.2014.11.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Herbert Tilg
- Department of Internal Medicine I, Endocrinology, Gastroenterology & Metabolism, Medical University Innsbruck, Innsbruck, Austria.
| | - Bin Gao
- Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland.
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Neuman MG, French SW, French BA, Seitz HK, Cohen LB, Mueller S, Osna NA, Kharbanda KK, Seth D, Bautista A, Thompson KJ, McKillop IH, Kirpich IA, McClain CJ, Bataller R, Nanau RM, Voiculescu M, Opris M, Shen H, Tillman B, Li J, Liu H, Thomes PG, Ganesan M, Malnick S. Alcoholic and non-alcoholic steatohepatitis. Exp Mol Pathol 2014; 97:492-510. [PMID: 25217800 PMCID: PMC4696068 DOI: 10.1016/j.yexmp.2014.09.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 09/08/2014] [Indexed: 02/08/2023]
Abstract
This paper is based upon the "Charles Lieber Satellite Symposia" organized by Manuela G. Neuman at the Research Society on Alcoholism (RSA) Annual Meetings, 2013 and 2014. The present review includes pre-clinical, translational and clinical research that characterize alcoholic liver disease (ALD) and non-alcoholic steatohepatitis (NASH). In addition, a literature search in the discussed area was performed. Strong clinical and experimental evidence lead to recognition of the key toxic role of alcohol in the pathogenesis of ALD. The liver biopsy can confirm the etiology of NASH or alcoholic steatohepatitis (ASH) and assess structural alterations of cells, their organelles, as well as inflammatory activity. Three histological stages of ALD are simple steatosis, ASH, and chronic hepatitis with hepatic fibrosis or cirrhosis. These latter stages may also be associated with a number of cellular and histological changes, including the presence of Mallory's hyaline, megamitochondria, or perivenular and perisinusoidal fibrosis. Genetic polymorphisms of ethanol metabolizing enzymes such as cytochrome p450 (CYP) 2E1 activation may change the severity of ASH and NASH. Alcohol mediated hepatocarcinogenesis, immune response to alcohol in ASH, as well as the role of other risk factors such as its co-morbidities with chronic viral hepatitis in the presence or absence of human immunodeficiency virus are discussed. Dysregulation of hepatic methylation, as result of ethanol exposure, in hepatocytes transfected with hepatitis C virus (HCV), illustrates an impaired interferon signaling. The hepatotoxic effects of ethanol undermine the contribution of malnutrition to the liver injury. Dietary interventions such as micro and macronutrients, as well as changes to the microbiota are suggested. The clinical aspects of NASH, as part of metabolic syndrome in the aging population, are offered. The integrative symposia investigate different aspects of alcohol-induced liver damage and possible repair. We aim to (1) determine the immuno-pathology of alcohol-induced liver damage, (2) examine the role of genetics in the development of ASH, (3) propose diagnostic markers of ASH and NASH, (4) examine age differences, (5) develop common research tools to study alcohol-induced effects in clinical and pre-clinical studies, and (6) focus on factors that aggravate severity of organ-damage. The intention of these symposia is to advance the international profile of the biological research on alcoholism. We also wish to further our mission of leading the forum to progress the science and practice of translational research in alcoholism.
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Affiliation(s)
- Manuela G Neuman
- In Vitro Drug Safety and Biotechnology, University of Toronto, Toronto, Ontario, Canada; Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
| | | | | | - Helmut K Seitz
- Centre of Alcohol Research, University of Heidelberg and Department of Medicine (Gastroenterology and Hepatology), Salem Medical Centre, Heidelberg, Germany
| | - Lawrence B Cohen
- Division of Gastroenterology, Sunnybrook Health Sciences Centre, Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Sebastian Mueller
- Centre of Alcohol Research, University of Heidelberg and Department of Medicine (Gastroenterology and Hepatology), Salem Medical Centre, Heidelberg, Germany
| | - Natalia A Osna
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Internal Medicine, Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Kusum K Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Internal Medicine, Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Devanshi Seth
- Drug Health Services, Royal Prince Alfred Hospital, Centenary Institute of Cancer Medicine and Cell Biology, Camperdown, NSW 2050, Australia; Faculty of Medicine, The University of Sydney, Sydney, NSW 2006, Australia
| | - Abraham Bautista
- Office of Extramural Activities, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Rockville, MD, USA
| | - Kyle J Thompson
- Department of Surgery, Carolinas Medical Center, Charlotte, NC, USA
| | - Iain H McKillop
- Department of Surgery, Carolinas Medical Center, Charlotte, NC, USA
| | - Irina A Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine and Department of Pharmacology; Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Craig J McClain
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine and Department of Pharmacology; Toxicology, University of Louisville School of Medicine, Louisville, KY, USA; Robley Rex Veterans Medical Center, Louisville, KY, USA
| | - Ramon Bataller
- Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Radu M Nanau
- In Vitro Drug Safety and Biotechnology, University of Toronto, Toronto, Ontario, Canada
| | - Mihai Voiculescu
- Division of Nephrology and Internal Medicine, Fundeni Clinical Institute and University of Medicine and Pharmacy, "Carol Davila", Bucharest, Romania
| | - Mihai Opris
- In Vitro Drug Safety and Biotechnology, University of Toronto, Toronto, Ontario, Canada; Family Medicine Clinic CAR, Bucharest, Romania
| | - Hong Shen
- Harbor-UCLA Medical Center, Torrance, CA, USA
| | | | - Jun Li
- Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Hui Liu
- Harbor-UCLA Medical Center, Torrance, CA, USA
| | - Paul G Thomes
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Internal Medicine, Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Murali Ganesan
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Internal Medicine, Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Steve Malnick
- Department Internal Medicine, Kaplan Medical Centre and Hebrew University of Jerusalem, Rehovot, Israel
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Lu F, Cao M, Wu B, Li XZ, Liu HY, Chen DZ, Liu SM. Urinary metabonomics study on toxicity biomarker discovery in rats treated with Xanthii Fructus. JOURNAL OF ETHNOPHARMACOLOGY 2013; 149:311-320. [PMID: 23831081 DOI: 10.1016/j.jep.2013.06.040] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 05/18/2013] [Accepted: 06/24/2013] [Indexed: 06/02/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Xanthii Fructus (XF) is commonly called "Cang-Erzi" in traditional Chinese medicine (TCM) and widely used for the treatment of sinusitis, headache, rheumatism, and skin itching. However, the clinical utilization of XF is relatively restricted owing to its toxicity. AIM OF THE STUDY To discover the characteristic potential biomarkers in rats treated with XF by urinary metabonomics. MATERIALS AND METHODS Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was applied in the study. The total ion chromatograms obtained from control and different dosage groups were distinguishable by a multivariate statistical analysis method. RESULTS The greatest difference in metabolic profile was observed between high dosage group and control group, and the metabolic characters in rats treated with XF were perturbed in a dose-dependent manner. The metabolic changes in response for XF treatment were observed in urinary samples, which were revealed by orthogonal projection to latent structures discriminate analysis (OPLS-DA), and 10 metabolites could be served as the potential toxicity biomarkers. In addition, the mechanism associated with the damages of lipid per-oxidation and the metabolic disturbances of fatty acid oxidation were investigated. CONCLUSIONS These results indicate that metabonomics analysis in urinary samples may be useful for predicting the toxicity induced by XF.
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Affiliation(s)
- Fang Lu
- Chinese Medicine Toxicological Laboratory, Institute of Traditional Chinese Medicine, Heilongjiang University of Chinese Medicine, Harbin 150040, PR China
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Huang LL, Wan JB, Wang B, He CW, Ma H, Li TW, Kang JX. Suppression of acute ethanol-induced hepatic steatosis by docosahexaenoic acid is associated with downregulation of stearoyl-CoA desaturase 1 and inflammatory cytokines. Prostaglandins Leukot Essent Fatty Acids 2013; 88:347-53. [PMID: 23474173 DOI: 10.1016/j.plefa.2013.02.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 02/03/2013] [Accepted: 02/06/2013] [Indexed: 12/22/2022]
Abstract
Excessive alcohol consumption can lead to hepatic steatosis. Omega-3 (n-3) polyunsaturated fatty acids (PUFA) have been shown to be effective in reducing hepatic accumulation of triglycerides (TG) by downregulation of TG biosynthesis in the liver. The aim of this study was to examine whether supplementation with the n-3 PUFA, docosahexaenoic acid (DHA), can effectively reduce acute alcohol-induced hepatic steatosis. Acute alcohol-induced hepatic steatosis was generated in 9-week-old male mice (C57BL/6J) by oral gavage of ethanol (4.7 g/kg BW) diluted in water (60%, v/v), with or without DHA (250 mg/kg BW), every 12 h for 3 administrations. Compared to the control (ethanol-alone) group, animals supplemented with DHA were protected against ethanol-induced TG accumulation in the liver. Accordingly, hepatic stearoyl-CoA desaturase-1 (SCD-1) expression, serum alanine aminotransferase (ALT) activity, and the levels of inflammatory cytokines (such as IL-6 and TNF-α) in the liver were significantly reduced, whereas the expression of heme oxygenase-1 (HO-1), an enzyme that can improve cell survival in liver tissue, was markedly increased in DHA-supplemented mice compared to the control animals. There were no differences in serum TG level and hepatic production of reactive oxygen species (ROS) between the two groups. Our findings demonstrate that DHA supplementation protects against acute ethanol-induced hepatic steatosis, which may be associated with reduced expression of SCD-1 and inflammatory cytokines.
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Affiliation(s)
- Li-Li Huang
- Laboratory for Lipid Medicine and Technology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02129, USA
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de Oliveira C, de Mattos ABM, Silva CBR, Mota JF, Zemdegs JCS. Nutritional and hormonal modulation of adiponectin and its receptors adipoR1 and adipoR2. VITAMINS AND HORMONES 2012; 90:57-94. [PMID: 23017712 DOI: 10.1016/b978-0-12-398313-8.00003-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Adiponectin is the most abundant plasma protein synthesized mostly by adipose tissue and is an insulin-sensitive hormone, playing a central role in glucose and lipid metabolism. Adiponectin effects are mediated via two receptors, adipoR1 and adipoR2. Several hormones and diet components that are involved in insulin resistance may impair insulin sensitivity at least in part by decreasing adiponectin and adiponectin receptors. Adiponectin expression and serum levels are associated with the amount and type of fatty acids and carbohydrate consumed. Other food items, such as vitamins, alcohol, sodium, green tea, and coffee, have been reported to modify adiponectin levels. Several hormones, including testosterone, estrogen, prolactin, glucocorticoids, catecholamines, and growth hormone, have been shown to inhibit adiponectin production, but the studies are still controversial. Even so, adiponectin is a potential therapeutic target in the treatment of diabetes mellitus and other diseases associated with hypoadiponectinemia.
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Affiliation(s)
- Cristiane de Oliveira
- Systemic Inflammation Laboratory, Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, USA.
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Kirpich IA, Feng W, Wang Y, Liu Y, Barker DF, Barve SS, McClain CJ. The type of dietary fat modulates intestinal tight junction integrity, gut permeability, and hepatic toll-like receptor expression in a mouse model of alcoholic liver disease. Alcohol Clin Exp Res 2011; 36:835-46. [PMID: 22150547 DOI: 10.1111/j.1530-0277.2011.01673.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Interactions between the gut, immune system, and the liver, as well as the type of fat in the diet, are critical components of alcoholic liver disease (ALD). The goal of the present study was to determine the effects of saturated fat (SF) and unsaturated fat (USF) on ethanol (EtOH)-induced gut-liver interactions in a mouse model of ALD. METHODS C57BL/6N mice were fed Lieber-DeCarli liquid diets containing EtOH and enriched in USF (corn oil) or SF (medium chain triglycerides:beef tallow). Control mice were pair-fed on an isocaloric basis. Liver injury and steatosis, blood endotoxin levels, intestinal permeability, and tight junction (TJ) integrity, as well as hepatic Toll-like receptor (TLR) gene expression, were evaluated. RESULTS After 8 weeks of EtOH feeding, liver injury and steatosis were observed in USF + EtOH group compared with control and SF + EtOH. Significantly increased intestinal permeability in conjunction with elevated blood endotoxin levels were observed in the ileal segments of the mice fed USF + EtOH. USF diet alone resulted in down-regulation of intestinal TJ protein mRNA expression compared with SF. Importantly, alcohol further suppressed TJ proteins in USF + EtOH, but did not affect intestinal TJ in SF + EtOH group. The type of fat in the diet alone did not affect hepatic TLR expression. Compared with control animals, hepatic TLR (TLR 1, 2, 3, 4, 7, 8, 9) mRNA expression was significantly (p < 0.05) increased in USF + EtOH, but not in SF + EtOH group. Notably, TLR5 was the only up-regulated TLR in both SF + EtOH and USF + EtOH groups. CONCLUSIONS Dietary fat is an important cofactor in alcohol-associated liver injury. We demonstrate that USF (corn oil/linoleic acid) by itself results in dysregulation of intestinal TJ integrity leading to increased gut permeability, and alcohol further exacerbates these alterations. We postulate that elevated blood endotoxin levels in response to USF and alcohol in conjunction with up-regulation of hepatic TLRs combine to cause hepatic injury in ALD.
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Affiliation(s)
- Irina A Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville School of Medicine, Kentucky, USA
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Hurt RT, Frazier TH, McClave SA, Cave MC. Pharmaconutrition for the Obese, Critically Ill Patient. JPEN J Parenter Enteral Nutr 2011; 35:60S-72S. [DOI: 10.1177/0148607111413775] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Ryan T. Hurt
- Department of Medicine
- Division of General Internal Medicine, Mayo Clinic, Rochester, Minnesota
| | - Thomas H. Frazier
- Department of Medicine
- Division of Gastroenterology, Hepatology, and Nutrition, University of Louisville School of Medicine, Louisville, Kentucky
| | - Stephen A. McClave
- Department of Medicine
- Division of Gastroenterology, Hepatology, and Nutrition, University of Louisville School of Medicine, Louisville, Kentucky
| | - Matt C. Cave
- Department of Medicine
- Division of Gastroenterology, Hepatology, and Nutrition, University of Louisville School of Medicine, Louisville, Kentucky
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Mei S, Ni HM, Manley S, Bockus A, Kassel KM, Luyendyk JP, Copple BL, Ding WX. Differential roles of unsaturated and saturated fatty acids on autophagy and apoptosis in hepatocytes. J Pharmacol Exp Ther 2011; 339:487-98. [PMID: 21856859 DOI: 10.1124/jpet.111.184341] [Citation(s) in RCA: 230] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Fatty acid-induced lipotoxicity plays a critical role in the pathogenesis of nonalcoholic liver disease. Saturated fatty acids and unsaturated fatty acids have differential effects on cell death and steatosis, but the mechanisms responsible for these differences are not known. Using cultured HepG2 cells and primary mouse hepatocytes, we found that unsaturated and saturated fatty acids differentially regulate autophagy and apoptosis. The unsaturated fatty acid, oleic acid, promoted the formation of triglyceride-enriched lipid droplets and induced autophagy but had a minimal effect on apoptosis. In contrast, the saturated fatty acid, palmitic acid, was poorly converted into triglyceride-enriched lipid droplets, suppressed autophagy, and significantly induced apoptosis. Subsequent studies revealed that palmitic acid-induced apoptosis suppressed autophagy by inducing caspase-dependent Beclin 1 cleavage, indicating cross-talk between apoptosis and autophagy. Moreover, our data suggest that the formation of triglyceride-enriched lipid droplets and induction of autophagy are protective mechanisms against fatty acid-induced lipotoxicity. In line with our in vitro findings, we found that high-fat diet-induced hepatic steatosis was associated with autophagy in the mouse liver. Potential modulation of autophagy may be a novel approach that has therapeutic benefits for obesity-induced steatosis and liver injury.
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Affiliation(s)
- Shuang Mei
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center MS 1018, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
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Gyamfi MA, Wan YJY. Pathogenesis of alcoholic liver disease: the role of nuclear receptors. Exp Biol Med (Maywood) 2010; 235:547-60. [PMID: 20463294 DOI: 10.1258/ebm.2009.009249] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Ethanol consumption causes fatty liver, which can lead to inflammation, fibrosis, cirrhosis and even liver cancer. The molecular mechanisms by which ethanol exerts its damaging effects are extensively studied, but not fully understood. It is now evident that nuclear receptors (NRs), including retinoid x receptor alpha and peroxisome proliferator-activated receptors, play key roles in the regulation of lipid homeostasis and inflammation during the pathogenesis of alcoholic liver disease (ALD). Given their pivotal roles in physiological processes, NRs represent potential therapeutic targets for the treatment and prevention of numerous metabolic and lipid-related diseases including ALD. This review summarizes the factors that contribute to ALD and the molecular mechanisms of ALD with a focus on the role of NRs.
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Affiliation(s)
- Maxwell Afari Gyamfi
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, Kansas City, Kansas 66160-7417, USA
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Abstract
This article discusses several subjects pertinent to a consideration of the role of gender and hormones in alcoholic liver injury (ALI). Beginning with an overview of factors involved in the pathogenesis of ALI, we review changes in sex hormone metabolism resulting from alcohol ingestion, summarize research that points to estrogen as a cofactor in ALI, consider evidence that gut injury is linked to liver injury in the setting of alcohol, and briefly review the limited evidence regarding sex hormones and gut barrier function. In both women and female animals, most studies reveal a propensity toward greater alcohol-induced liver injury due to female gender, although exact hormonal influences are not yet understood. Thus, women and their physicians should be alert to the dangers of excess alcohol consumption and the increased potential for liver injury in females.
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Feng L, Song YF, Guan QB, Liu HJ, Ban B, Dong HX, Hou XL, Lee KO, Gao L, Zhao JJ. Long-term ethanol exposure inhibits glucose transporter 4 expression via an AMPK-dependent pathway in adipocytes. Acta Pharmacol Sin 2010; 31:329-40. [PMID: 20173759 DOI: 10.1038/aps.2010.11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
AIM The roles of AMP-activated protein kinase (AMPK) and myocyte enhancer factor 2 isoforms (MEF2A, D) as mediators of the effects of ethanol on glucose transporter 4 (GLUT4) expression are unclear. We studied the effects of ethanol in adipocytes in vivo and in vitro. METHODS Thirty-six male Wistar rats were divided into three groups and given ethanol in a single daily dose of 0, 0.5, or 5 g/kg for 22 weeks. The expression of AMPK, MEF2 isoforms A and D, and GLUT4 was measured and compared in the three groups. The existence of the AMPK/MEF2/GLUT4 pathway in adipocytes and the effects of ethanol on this pathway were studied in (a) epididymal adipose tissue from six male Wistar rats subcutaneously injected with 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR, an AMPK activator) or with 0.9% NaCl (control); and (b) isolated rat and human adipocytes treated with or without ethanol, AICAR, and compound C (a selective AMPK inhibitor). Expression of AMPK, MEF2, and GLUT4 was measured by RT-PCR and Western blotting. RESULTS (1) Long-term ethanol exposure decreased activated AMPK, MEF2A, MEF2D, and GLUT4 expression in rat adipose tissue. (2) In rat and human adipocytes, AICAR-induced AMPK activation, with subsequent elevation of MEF2 and GLUT4 expression, was inhibited by compound C. (3) In vitro ethanol-treatment suppressed the AMPK/MEF2/GLUT4 pathway. CONCLUSION The AMPK/MEF2/GLUT4 pathway exists in both rat and human adipocytes, and activated AMPK may positively regulate MEF2 and GLUT4 expression. Ethanol inhibition of this pathway leads to decreased GLUT4 expression, thus reducing insulin sensitivity and glucose tolerance.
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Abstract
INTRODUCTION Oxidative stress plays an important role in pathogenesis of alcoholic liver injury. The main source of free oxygen species is cytochrome P450-dependent monooxygenase, which can be induced by ethanol. ROLE OF CYTOCHROME P4502E1 IN ETHANOL-INDUCED OXIDATIVE STRESS: Reactive oxygen species produced by this enzyme are more important in intracellular oxidative damage compared to species derived from activated phagocytes. Free radicals lead to lipid peroxidation, enzymatic inactivation and protein oxidation. ROLE OF MITOCHONDRIA IN ALCOHOL-INDUCED OXIDATIVE STRESS. Production of mitochondrial reactive oxygen species is increased, and glutathione content is decreased in chronically ethanol-fed animals. Oxidative stress in mitochondria leads to mitochondrial DNA damage and has a dual effect on apoptosis. ROLE OF KUPFFER CELLS IN ALCOHOL-INDUCED LIVER INJURY: Chronic ethanol consumption is associated with increased release of endotoxin from gut lumen into portal circulation. Endotoxin activates Kupffer cells, which then release proinflammatory cytokines and oxidants. ROLE OF NEUTROPHILS IN ALCOHOL-INDUCED LIVER INJURY: Alcoholic liver injury leads to the accumulation of neutrophils, which release reactive oxygen species and lysosomal enzymes and contribute to hepatocyte damage and necrosis. ROLE OF NITRIC OXIDE IN ALCOHOL-INDUCED OXIDATIVE STRESS: High amounts of nitric oxide contribute to the oxidative damage, mainly by generating peroxynitrites. ROLE OF ANTIOXIDANTS IN ETHANOL-INDUCED OXIDATIVE STRESS: Chronic ethanol consumption is associated with reduced liver glutathione and alpha-tocopherol level and with reduced superoxide dismutase, catalase and glutathione peroxidase activity. CONCLUSION Oxidative stress in alcoholic liver disease is a consequence of increased production of oxidants and decreased antioxidant defense in the liver.
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Hwang J. Diets with corn oil and/or low protein increase acute acetaminophen hepatotoxicity compared to diets with beef tallow in a rat model. Nutr Res Pract 2009; 3:95-101. [PMID: 20016708 PMCID: PMC2788177 DOI: 10.4162/nrp.2009.3.2.95] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 05/07/2009] [Accepted: 06/04/2009] [Indexed: 11/23/2022] Open
Abstract
It has been reported that dietary polyunsaturated fats (PUFA) increase liver injury in response to ethanol feeding. We tested the hypothesis that diets rich in linoleic acid (18:2n-6) would affect acute liver injury after acetaminophen injection and that protein restriction might exacerbate the liver injury. We examined effects of feeding diets with either 15% (wt/wt) corn oil or 14% beef tallow and 1% corn oil for six weeks with either 6 or 20 g/100 g protein on acute hepatotoxicity. After the feeding period, liver injury was induced by injecting either with 600 mg/kg body weight acetaminophen suspended in gum arabic-based vehicle, or with vehicle alone during fasting status. Samples of liver and plasma were taken for analyses of hepatic glutathione (GSH) levels and liver-specific enzymes [(Glutamate-pyruvate transaminase (GPT) and glutamate-oxaloacetate transaminase (GOT)], respectively. Whereas GSH level was significantly lower in only group fed 15% corn oil with 6 g/100 g protein among acetaminophen-treated groups, activities of GPT and GOT were significantly elevated in all groups except the one fed beef tallow with 20 g/100 g protein, suggesting low protein might exacerbate drug-induced hepatotoxicity. The feeding regimens changed the ratio of 18:2n-6 to oleic acid (18:1n-9) in total liver lipids approximately five-fold, and produced modest changes in arachidonic acid (20:4n-6). We conclude that diets with high 18:2n-6 promote acetaminophen-induced liver injury compared to diets with more saturated fatty acids (SFA). In addition, protein restriction appeared to exacerbate the liver injury.
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Affiliation(s)
- Jinah Hwang
- Department of Foods and Nutrition, College of Natural Sciences, Myongji University, San 38-2 Nam-dong, Cheoin-gu, Yongin, Gyeonggi 449-728, Korea
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Tipoe GL, Liong EC, Casey CA, Donohue TM, Eagon PK, So H, Leung TM, Fogt F, Nanji AA. A voluntary oral ethanol-feeding rat model associated with necroinflammatory liver injury. Alcohol Clin Exp Res 2008; 32:669-82. [PMID: 18341647 DOI: 10.1111/j.1530-0277.2008.00623.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND The intragastric (IG) ethanol infusion model results in fatty liver, necrosis, inflammation and fibrosis. This model was utilized to study the pathogenesis of alcoholic liver disease (ALD). Disadvantages of the IG model include maintenance of the animals and equipment expense. To develop a voluntary feeding model for ALD, we took advantage of two important observations in the IG model: (i) female rats demonstrate greater severity of alcohol-induced liver injury than males and (ii) rats fed fish oil as a source of fatty acids develop more severe alcoholic liver injury than rats fed other fatty acids with ethanol. METHODS Female Wistar rats (205 to 220 g) were fed for 8 weeks a diet containing 8% ethanol, fish oil (30% of calories), protein, and dextrose. Pair-fed controls (FD) received dextrose in amounts isocaloric to ethanol. The following measurements were made: liver pathology [fatty liver (0 to 4), necrosis, inflammation and fibrosis by Sirius Red], endotoxin and alanine aminotransferase (ALT) in plasma, urine ethanol, lipid peroxidation, nuclear factor kappa-B (NF-kappaB) and mRNA levels for tumor necrosis factor-alpha (TNF-alpha), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). Protein levels for iNOS and nitrotyrosine were evaluated by immunohistochemistry and Western Blot analysis. Liver proteasome and cytochrome P450 2E1 activity and protein levels of asialoglycoprotein receptor (ASGPR) were also evaluated. In addition, mRNA levels of fibrogenic markers were assessed. RESULTS All animals lost weight for the initial 2 to 3 weeks but then gained weight until killing at 8 weeks. There was, however, a significant difference (p < 0.05) in weight between the ethanol-fed (Etoh) and (FD) groups at the end of the experiment. The mean urine ethanol levels ranged between 190 and 240 mg/dl. The severity of pathological changes was greater (p < 0.01) in Etoh vs. FD: fatty liver, 3.0 +/- 1.2 vs. 1.2 +/- 0.4; necrosis (foci/mm(2)), 3.9 +/- 2.3 vs. 0.4 +/- 0.3; inflammation (cells/mm(2)), 19.0 +/- 6.3 vs. 1.8 +/- 0.6. Centrilobular collagen deposition (% area), assessed by Sirius Red staining, was greater in Etoh vs. FD. Levels of endotoxin, ALT, CYP2E1 and lipid peroxidation markers were also higher (p < 0.01) in Etoh vs. FD. Levels of NF-kappaB and mRNA of pro-inflammatory mediators (TNF-alpha, COX-2, iNOS) and procollagen-I were increased (p < 0.05) in ethanol-fed rats. Immunohistochemical analysis showed more intense staining for both iNOS and nitrotyrosine in the centrilobular areas in the Etoh vs. FD groups. The greater area of positive staining for iNOS and nitrotyrosine in Etoh vs. FD was confirmed by Western Blot analysis. An increase in the expression of mRNA for profibrogenic genes (p < 0.05) was seen in ethanol-fed rats. CONCLUSIONS A voluntary feeding regimen consisting of fish oil and ethanol in female rats is technically less demanding yet produces pathological and biochemical changes similar to those observed with the IG model. Pathological changes include fatty liver, necrosis and inflammation. Increased NF-kappaB and mRNA and protein levels of the pro-inflammatory mediators TNF-alpha, COX-2 and iNOS, coincided with the presence of necroinflammatory changes. The voluntary feeding regimen is proposed as an alternative to the IG model in the study of alcoholic liver injury.
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Affiliation(s)
- George L Tipoe
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
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You M, Cao Q, Liang X, Ajmo JM, Ness GC. Mammalian sirtuin 1 is involved in the protective action of dietary saturated fat against alcoholic fatty liver in mice. J Nutr 2008; 138:497-501. [PMID: 18287356 DOI: 10.1093/jn/138.3.497] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study was undertaken to elucidate the mechanism underlying the protective effect of a high saturated fat (HSF) diet against the development of alcoholic fatty liver in mice. We tested the effects of a HSF diet on the ethanol-mediated increase in hepatic sterol regulatory element binding protein 1 (SREBP-1) activity. Thirty-two male mice were divided into 4 groups and fed liquid diets consisting of either a high polyunsaturated fat (40% of energy from corn oil) or a HSF (40% of energy from cocoa butter) diet with or without ethanol for 4 wk. In the ethanol-containing diets, ethanol was substituted for an equivalent amount of carbohydrate to provide 27.5% of the total energy. Control mice were pair-fed the same volume of liquid diets as the ethanol-fed mice. The HSF diet suppressed the increase in mature SREBP-1 protein and prevented increased mRNA of the SREBP-1-regulated lipogenic enzymes in the ethanol-fed mice (P < 0.05). Sirtuins 1 (SIRT1), a NAD+-dependent class III histone deacetylase, was upregulated by ethanol administration in mice fed the HSF diet (P < 0.05). The HSF diet blocked histone H3 at lysine 9 (lys9) hyperacetylation and attenuated association of acetylated histone H3-Lys9 with the promoters of mitochondrial glycerol-3-phosphate acyltransferase and stearoyl-CoA desaturase 1 in the livers of the ethanol-fed mice. These results suggest that the protective effects of HSF diet against the development of alcoholic liver steatosis may occur via regulation of the hepatic SIRT1-SREBP-1-histone H3 axis, suppressing the expression of genes encoding lipogenic enzymes and slowing the synthesis of hepatic fatty acids.
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Affiliation(s)
- Min You
- Department of Molecular Pharmacology and Physiology, University of South Florida Health Sciences Center, Tampa, FL 33612, USA.
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Tipoe GL, Liong EC, Leung TM, Nanji AA. A voluntary oral-feeding rat model for pathological alcoholic liver injury. Methods Mol Biol 2008; 447:11-31. [PMID: 18369908 DOI: 10.1007/978-1-59745-242-7_2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The variety of animal models used in the study of alcoholic liver disease reflects the formidable task of developing a model that replicates the human disease. We show that oral feeding of fatty acids derived from fish oil and ethanol induces fatty liver, necrosis, inflammation, and fibrosis. Together with the study of oxidative and nitrosative stress markers, cytokines, proteasome function, and protein studies, this model has provided an inexpensive and technically simple method of establishing pathological alcoholic liver injury.
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Affiliation(s)
- George L Tipoe
- Department of Anatomy, The University of Hong Kong, Hong Kong, SAR China
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Abstract
The involvement of free radical mechanisms in the pathogenesis of alcoholic liver disease (ALD) is demonstrated by the detection of lipid peroxidation markers in the liver and the serum of patients with alcoholism, as well as by experiments in alcohol-feed rodents that show a relationship between alcohol-induced oxidative stress and the development of liver pathology. Ethanol-induced oxidative stress is the result of the combined impairment of antioxidant defences and the production of reactive oxygen species by the mitochondrial electron transport chain, the alcohol-inducible cytochrome P450 (CYP) 2E1 and activated phagocytes. Furthermore, hydroxyethyl free radicals (HER) are also generated during ethanol metabolism by CYP2E1. The mechanisms by which oxidative stress contributes to alcohol toxicity are still not completely understood. The available evidence indicates that, by favouring mitochondrial permeability transition, oxidative stress promotes hepatocyte necrosis and/or apoptosis and is implicated in the alcohol-induced sensitization of hepatocytes to the pro-apoptotic action of TNF-alpha. Moreover, oxidative mechanisms can contribute to liver fibrosis, by triggering the release of pro-fibrotic cytokines and collagen gene expression in hepatic stellate cells. Finally, the reactions of HER and lipid peroxidation products with hepatic proteins stimulate both humoral and cellular immune reactions and favour the breaking of self-tolerance during ALD. Thus, immune responses might represent the mechanism by which alcohol-induced oxidative stress contributes to the perpetuation of chronic hepatic inflammation. Together these observations provide a rationale for the possible clinical application of antioxidants in the therapy for ALD.
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Affiliation(s)
- Emanuele Albano
- Department of Medical Sciences, University of A. Avogadro East Piedmont, Novara, Italy.
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You M, Considine RV, Leone TC, Kelly DP, Crabb DW. Role of adiponectin in the protective action of dietary saturated fat against alcoholic fatty liver in mice. Hepatology 2005; 42:568-77. [PMID: 16108051 PMCID: PMC1398076 DOI: 10.1002/hep.20821] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The protective effect of dietary saturated fatty acids against the development of alcoholic liver disease has long been known, but the underlying mechanism is not completely understood. We examined the involvement of the adipocyte hormone adiponectin. Circulating adiponectin levels were significantly elevated by chronic ethanol administration to mice consuming a diet high in saturated fat. The increase in circulating adiponectin was associated with the activation a set of hepatic signaling pathways mediated through AMP-activated protein kinase, PPAR-alpha, and PPAR-gamma coactivator alpha, which in turn led to markedly increased rates of fatty acid oxidation, prevention of hepatic steatosis, and alleviation of liver enzyme changes. Furthermore, treatment of rat 3T3-L1 adipocytes with saturated fatty acids (palmitic or stearic acids) in the presence of ethanol increased secretion of adiponectin and enhanced activity of a mouse adiponectin promoter. In conclusion, the protective action of saturated fat against the development of alcoholic fatty liver in mice is partially mediated through induction of adiponectin. The present findings suggest a novel paradigm for dietary fatty acids in the pathogenesis of alcoholic liver disease and provide a promising therapeutic strategy-nutritional modulation of adiponectin-in treating human alcoholic fatty liver disease.
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Key Words
- adipose tissue
- hormone
- signal transduction
- amp-activated kinase
- liver steatosis
- ampk, amp-activated protein kinase
- acc, acetyl-coa carboxylase
- cpt i, carnitine palmitoyltransferase i
- pparα, peroxisome proliferator-activated receptor α
- pparγ, peroxisome proliferator-activated receptor γ
- pgc-1α, peroxisome proliferator-activated receptor γ co-activator-alpha
- aox, acetyl-coa oxidase
- ppre, ppar response element
- β-ohb, β-hydroxybutyrate
- ffa, free fatty acids
- alt ,alanine aminotransferase
- rt-pcr, reverse transcription-polymerase chain reaction
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Affiliation(s)
- Min You
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.
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Cabré E, Hernández-Pérez JM, Fluvià L, Pastor C, Corominas A, Gassull MA. Absorption and transport of dietary long-chain fatty acids in cirrhosis: a stable-isotope-tracing study. Am J Clin Nutr 2005; 81:692-701. [PMID: 15755841 DOI: 10.1093/ajcn/81.3.692] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND In rats, 30-70% of dietary fatty acids (FAs) are absorbed through the portal vein. Whether this occurs in humans is unknown, but it may occur in persons with cirrhosis, who show a blunted chylomicronemic response to dietary fat without significant steatorrhea. OBJECTIVE The objective was to investigate whether portal FA absorption occurs in humans with cirrhosis. DESIGN Six control subjects and 10 patients with (n = 5) and without (n = 5) cirrhotic ascites were fed [1-(13)C]palmitic and oleic acids in a test meal. Samples were drawn before and 30, 60, 90, 120, 240, 360, 480, and 720 min afterward for plasma [1-(13)C]-labeled FAs and breath (13)CO(2) assay. Fecal [1-(13)C]-labeled FAs were also measured. RESULTS [1-(13)C]-Labeled FAs increased in chylomicrons in all groups, but less in ascitic cirrhotic patients, because their median area under the curve from 120 to 720 min was significantly lower than in the control subjects for labeled palmitate [520 (interquartile range: 192-1137) compared with 2862 (2674-4175) micromol . min/L] and oleate [829 (781-1263) compared with 3119 (2939-4986) micromol . min/L]. [1-(13)C]-Labeled FA enrichment of VLDL was also lower in cirrhotic patients. [1-(13)C]-Labeled FA in free FAs peaked earlier in ascitic than in nonascitic patients and control subjects, mainly for [1-(13)C]oleate, and the median area under the curve from 0 to 120 min was significantly higher in ascitic patients than in control subjects [301 (255-400) compared with 48 (34-185) micromol . min/L]. Fecal excretion of [1-(13)C]-labeled FA was negligible and not significantly different between groups. CONCLUSIONS The low [1-(13)C]-labeled FA concentrations in chylomicrons and VLDL, without increased fecal losses, confirm previous data in cirrhotic patients with the use of an unlabeled fat load. The earlier [1-(13)C]-labeled FA appearance in free FAs supports the portal absorption of dietary fat in patients with advanced cirrhosis with spontaneous portal-systemic shunting.
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Affiliation(s)
- Eduard Cabré
- Department of Gastroenterology, Hospital Universitari Germans Trias i Pujol, Badalona, Catalonia, Spain
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Donohue TM, Kharbanda KK, Casey CA, Nanji AA. Decreased proteasome activity is associated with increased severity of liver pathology and oxidative stress in experimental alcoholic liver disease. Alcohol Clin Exp Res 2005; 28:1257-63. [PMID: 15318126 DOI: 10.1097/01.alc.0000134233.89896.19] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Because of its role in degrading the bulk of intracellular proteins and eliminating damaged proteins, the proteasome is important in maintaining cell viability. Previously, we showed a 35-40% decrease in proteasome peptidase activity when ethanol was administered to rats by intragastric infusion. We hypothesized that this reduction was caused by ethanol-elicited oxidative stress, the degree of which varies depending on the method of ethanol administration. This study examined the relationship of proteasome activity and content with ethanol-induced oxidative stress and the degree of liver injury. METHODS Rats were given ethanol or isocaloric dextrose-containing liquid diets by intragastric infusion for 1 month. The diets contained medium-chain triglycerides (MCT), palm oil (PO), corn oil (CO), or fish oil (FO) as the principal source of fat. RESULTS Rats given ethanol and MCT exhibited no significant liver pathology, whereas cumulative pathology scores in ethanol-fed rats given PO, CO, or FO were 2.5, 5.4 and 7.0, respectively, indicating that ethanol and FO caused the greatest liver damage. The severity of liver pathology in the last three groups of animals correlated with levels of lipid peroxides and serum 8-isoprostanes. Alpha smooth muscle actin, an indicator of stellate cell activation, was increased relative to controls in the livers of all ethanol-fed rats except FO-fed animals, in which both control and ethanol-fed rats had similar levels of this protein. In livers of CO and FO ethanol-fed rats, proteasome chymotrypsin-like activity was decreased by 55-60%, but there was no quantitative alteration in 20S proteasome subunit content. In contrast, ethanol affected neither proteasome activity nor its content in MCT- and PO-treated animals. CONCLUSIONS Our findings indicate that the severity of liver injury and ethanol-induced oxidative stress is associated with a reduction in proteasome catalysis.
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Affiliation(s)
- Terrence M Donohue
- Liver Study Unit, The Omaha Department of Veterans Affairs Medical Center, Omaha, Nebraska 68105, USA.
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Piquet MA, Roulet M, Nogueira V, Filippi C, Sibille B, Hourmand-Ollivier I, Pilet M, Rouleau V, Leverve XM. Polyunsaturated fatty acid deficiency reverses effects of alcohol on mitochondrial energy metabolism. J Hepatol 2004; 41:721-9. [PMID: 15519643 DOI: 10.1016/j.jhep.2004.07.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2004] [Revised: 06/26/2004] [Accepted: 07/02/2004] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS Polyunsaturated fatty acids (PUFA) deficiency is common in patients with alcoholic liver disease. The suitability of reversing such deficiency remains controversial. The aim was to investigate the role played by PUFA deficiency in the occurrence of alcohol-related mitochondrial dysfunction. METHODS Wistar rats were fed either a control diet with or without alcohol (control and ethanol groups) or a PUFA deficient diet with or without alcohol (PUFA deficient and PUFA deficient+ethanol groups). After 6 weeks, liver mitochondria were isolated for energetic studies and fatty acid analysis. RESULTS Mitochondria from ethanol fed rats showed a dramatic decrease in oxygen consumption rates and in cytochrome oxidase activity. PUFA deficiency showed an opposite picture. PUFA deficient+ethanol group roughly reach control values, regarding cytochrome oxidase activity and respiratory rates. The relationship between ATP synthesis and respiratory rate was shifted to the left in ethanol group and to the right in PUFA-deficient group. The plots of control and PUFA deficient+ethanol groups were overlapping. Phospholipid arachidonic over linoleic ratio closely correlated to cytochrome oxidase and oxygen uptake. CONCLUSIONS PUFA deficiency reverses alcohol-related mitochondrial dysfunction via an increase in phospholipid arachidonic over linoleic ratio, which raises cytochrome oxidase activity. Such deficiency may be an adaptive mechanism.
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Alvarez MA, Cabré E, Lorenzo-Zúñiga V, Montoliu S, Planas R, Gassull MA. Combining steroids with enteral nutrition: a better therapeutic strategy for severe alcoholic hepatitis? Results of a pilot study. Eur J Gastroenterol Hepatol 2004; 16:1375-80. [PMID: 15618848 DOI: 10.1097/00042737-200412000-00023] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND Results of a previous randomized controlled trial comparing the outcome of patients with severe alcoholic hepatitis treated with total enteral nutrition (TEN) or corticosteroids suggest that these treatments act through different mechanisms and may be complementary. We report a pilot study of combined treatment with TEN and a shorter course of steroids in patients with severe alcoholic hepatitis. METHODS Thirteen patients with severe alcoholic hepatitis were treated with systemic steroids and TEN. Steroid therapy started with 40 mg oral prednisolone daily, and was progressively tapered as soon as both serum bilirubin and prothrombin time decreased below 50% of their baseline values. TEN (2000 kcal, or 8374 kJ, daily) was administered throughout the hospital stay. Patients were followed for at least 12 months or until death. RESULTS Tapering of prednisolone dose could be started after a mean (SD) of 15.4 (3.8) days, whereas TEN was maintained for 22 (3.8) days. TEN was tolerated in 10 of the 13 patients. The major adverse event attributable to therapy was hyperglycemia requiring insulin therapy, which occurred in 12 of 13 patients. Only two patients (15%) died during the treatment period. Another patient died within the first 2 months of follow-up. In no case was the death due to infectious complications, despite two-thirds of patients developing infections during the treatment period. Infections during follow-up occurred only in three patients. CONCLUSION This pilot study suggests that TEN associated with a short course of steroids could be a good therapeutic strategy for severe alcoholic hepatitis. This possibility deserves investigation in a randomized controlled trial.
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Affiliation(s)
- Marco A Alvarez
- Department of Gastroenterology, University Hospital Germans Trias i Pujol, Badalona, Catalonia, Spain
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Caldwell SH, Chang CY, Nakamoto RK, Krugner-Higby L. Mitochondria in nonalcoholic fatty liver disease. Clin Liver Dis 2004; 8:595-617, x. [PMID: 15331066 DOI: 10.1016/j.cld.2004.04.009] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nonalcoholic fatty liver (NAFL) is associated with fundamental issues of fat metabolism and insulin resistance. These abnormalities have been linked to impairment of ATP homeostasis, and a growing body of literature has reported mitochondrial abnormalities in various forms of hepatic steatosis. The changes are evident as structural abnormalities, including greatly increased size and the development of crystalline inclusions, and are usually regarded as pathologic, reflecting either a protective or degenerative response to injury. Although the relationships between structural changes,decreased mitochondrial function, and disease states are becoming clearer, the molecular basis for the perturbations is not well understood. Oxidative damage is the most likely causative process and may result in alterations of mitochondrial DNA (mtDNA), stimulated apoptotic pathways, and increased propensity for necrosis.Overall mitochondrial health likely depends on multiple factors including the integrity of the mtDNA, the composition of cellular lipids, lipoprotein trafficking, the balance of pro- and antioxidant factors, and the metabolic demands placed on the liver. Mitochondrial dysfunction may play a role in numerous clinical conditions associated with NAFL, such as hepatocellular carcinoma, lipodystrophy,age-related insulin resistance, gut dysmotility, cryptogenic cirrhosis, a mild form of gaze palsy, and possibly other more severe neurodegenerative diseases. The prominent role of mitochondrial dysfunction in NAFL provides a new and exciting paradigm in which to view this disorder, its complications, and potential dietary and pharmacologic intervention.
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Affiliation(s)
- Stephen H Caldwell
- Division of Gastroenterology and Hepatology, University of Virginia Health System, PO Box 800708, Charlottesville, VA 22908, USA.
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Nanji AA, Dannenberg AJ, Jokelainen K, Bass NM. Alcoholic liver injury in the rat is associated with reduced expression of peroxisome proliferator-alpha (PPARalpha)-regulated genes and is ameliorated by PPARalpha activation. J Pharmacol Exp Ther 2004; 310:417-24. [PMID: 15016835 DOI: 10.1124/jpet.103.064717] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Alcoholic liver disease is associated with a state of hepatic fatty acid overload. We examined the effect of ethanol and different types of dietary fat on the expression of mRNA for liver fatty acid binding protein (L-FABP), peroxisome proliferator-activated receptor-alpha (PPARalpha), and peroxisomal fatty acyl CoA oxidase (FACO). Four groups of rats (n = 5) were fed intragastrically, a liquid diet with or without ethanol (10-16 g/kg/day) for 4 weeks. Pair-fed controls received isocaloric amounts of dextrose. The source of fat was either corn oil or fish oil. Ethanolfed rats developed fatty liver, necrosis, and inflammation; the changes were more severe in the fish oil-ethanol (FE) rats. PPARalpha mRNA levels were not different between groups, although there was a trend toward increased levels in ethanol-fed rats. We calculated L-FABP/PPARalpha and FACO/PPARalpha ratios as a measure of FACO and L-FABP up-regulation relative to PPARalpha expression. Both FACO/PPARalpha and L-FABP/PPARalpha ratios were significantly decreased in FE rats. However, only L-FABP/PPARalpha was decreased in corn oil plus ethanol rats. Also, the level of L-FABP/mRNA correlated inversely with the degree of fatty liver in ethanol-fed rats. Since expression of PPARalpha response genes was impaired in ethanol-fed rats, we determined whether activation of PPARalpha would normalize the PPARalpha response and prevent the pathological changes in ethanol-fed rats. Treatment with clofibrate, a PPARalpha-activating ligand, led to a marked decrease in fatty liver and complete abrogation of necroinflammatory changes in FE rats. Also, nuclear factor kappaB activation and up-regulation of tumor necrosis factor-alpha and cyclooxygenase-2 was also abolished in clofibrate-treated rats. We conclude that adaptive gene regulation of FACO and L-FABP by PPARalpha is impaired in ethanol-fed rats and that treatment with clofibrate, a PPARalpha ligand, prevents alcohol-induced pathological liver injury, possibly by reversing the above changes.
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Affiliation(s)
- Amin A Nanji
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104-4283, USA.
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Farina M, Soares FA, Feoli A, Roehring C, Brusque AM, Rotta L, Perry ML, Souza DO, Rocha JBT. In vitro effects of selenite and mercuric chloride on liver thiobarbituric acid-reactive substances and non-protein thiols from rats: influences of dietary cholesterol and polyunsaturated and saturated fatty acids. Nutrition 2003; 19:531-5. [PMID: 12781854 DOI: 10.1016/s0899-9007(02)01078-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE We measured the in vitro effects of mercuric chloride (Hg2+) and selenite (Se4+) on hepatic 2-thiobarbituric acid-reactive substances (TBARS) and non-protein sulfhydryl (NPSH) levels of rats fed diets enriched with polyunsaturated or saturated fatty acids with and without cholesterol. METHODS Male Wistar rats (21 d old) were assigned to one of four groups and fed diets containing 20% soybean oil, 20% soybean oil plus 1% cholesterol, 20% coconut oil, or coconut oil plus 1% cholesterol. After the feeding period (6 wk), body weight gain was equal in all groups. TBARS levels and NPSH content were measured after in vitro exposure to mercuric chloride (100 microM) and sodium selenite (25 microM) for 1 h. RESULTS The lipid peroxidation, measured as TBARS levels in the control group, were statistically higher in hepatic homogenates of rats fed diets containing soybean oil than in groups fed coconut oil (P = 0.009). However, cholesterol supplementation did not change TBARS levels. Selenite alone did not modify TBARS production, whereas mercury alone significantly increased TBARS levels. Moreover, Se4+ protected against mercury-induced lipid peroxidation only in rats fed diets containing coconut oil. In the control group, dietary fat acids did not change NPSH levels. Selenite produced higher oxidative effects toward NPSH content, whereas Hg2+ decreased NPSH levels only in liver from rats fed diets containing soybean oil. NPSH levels were higher after concomitant exposure to Se4+ and Hg2+ chloride that after exposure to Se4+ alone, suggesting an interaction between Hg2+ and Se4+. Catalase activity was higher in animals fed diets containing soybean oil. Dietary cholesterol decreased glutathione peroxidase activity. CONCLUSION Together these results indicated that the protective effect of Se4+ against mercury-induced lipid peroxidation depends on dietary fat saturation.
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Affiliation(s)
- Marcelo Farina
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 Anexo, Bairro Santana, 90035-0003 Porto Alegre, RS, Brazil.
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Abstract
Fatty liver disease that develops in the absence of alcohol abuse is recognized increasingly as a major health burden. This report summarizes the presentations and discussions at a Single Topic Conference held September 20-22, 2002, and sponsored by the American Association for the Study of Liver Diseases. The conference focused on fatty liver disorders. Estimates based on imaging and autopsy studies suggest that about 20% to 30% of adults in the United States and other Western countries have excess fat accumulation in the liver. About 10% of these individuals, or fully 2% to 3% of adults, are estimated to meet current diagnostic criteria for nonalcoholic steatohepatitis (NASH). Sustained liver injury leads to progressive fibrosis and cirrhosis in a fraction, possibly up to one third, of those with NASH, and NASH may be a cause of cryptogenic cirrhosis. NASH is now a significant health issue for obese children as well, leading to cirrhosis in some. The diagnostic criteria for NASH continue to evolve and rely on the histologic findings of steatosis, hepatocellular injury (ballooning, Mallory bodies), and the pattern of fibrosis. Generally recognized indications for biopsy include establishing the diagnosis and staging of the injury, but strict guidelines do not exist. Liver enzymes are insensitive and cannot be used reliably to confirm the diagnosis or stage the extent of fibrosis. Older age, obesity, and diabetes are predictive of fibrosis. The pathogenesis of NASH is multifactorial. Insulin resistance may be an important factor in the accumulation of hepatocellular fat, whereas excess intracellular fatty acids, oxidant stress, adenosine triphosphate (ATP) depletion, and mitochondrial dysfunction may be important causes of hepatocellular injury in the steatotic liver. Efforts are underway to refine the role of insulin resistance in NASH and determine whether improving insulin sensitivity pharmacologically is an effective treatment. An altered lifestyle may be a more effective means of improving insulin sensitivity. The research agenda for the future includes establishing the role of insulin resistance and abnormal lipoprotein metabolism in NASH, determining the pathogenesis of cellular injury, defining predisposing genetic abnormalities, identifying better noninvasive predictors of disease, and defining effective therapy.
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Kono H, Fujii H, Asakawa M, Yamamoto M, Matsuda M, Maki A, Matsumoto Y. Protective effects of medium-chain triglycerides on the liver and gut in rats administered endotoxin. Ann Surg 2003; 237:246-55. [PMID: 12560783 PMCID: PMC1522134 DOI: 10.1097/01.sla.0000048450.44868.b1] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine if medium-chain triglycerides (MCTs) prevent organ injuries and mortality in rats administered endotoxin and to investigate effects of MCT on the gut. SUMMARY BACKGROUND DATA Since dietary MCTs prevent alcohol-induced liver injury by inhibiting activation of Kupffer cells in the enteral feeding model, the authors hypothesized that MCT could prevent deleterious conditions in endotoxemia. METHODS After a preliminary experiment determined the optimal dose of MCT, rats were given MCT (5 g/kg per day) or the same dose of corn oil by gavage daily for 1 week. Then, lipopolysaccharide (LPS) was administered intravenously and survival was assessed for the next 24 hours. For analysis of mechanisms, rats were killed 9 hours after LPS injection and serum and liver sections were collected. To investigate effects of MCT on the gut, pathologic change, permeability, and microflora were assessed. Kupffer cells isolated by collagenase digestion and differential centrifugation were used for endotoxin receptor CD14 immunoblotting, phagocytic index, and TNF-alpha production assay. RESULTS All rats given corn oil died after LPS administration; however, this mortality was prevented by MCT in a dose-dependent manner. Rats given corn oil showed liver injury after LPS administration. In contrast, MCT prevented this pathologic change nearly completely. MCT blunted CD14 expression on the Kupffer cells and TNF-alpha production by isolated Kupffer cells; however, there were no differences in phagocytic index between the two groups. The length of the intestinal epithelium was increased in the MCT group compared to the corn oil group. Further, after LPS administration, increases in gut permeability and injury were prevented by MCT. Importantly, MCT also prevented hepatic energy charge and gut injuries in this condition. CONCLUSIONS Enteral feeding using MCT could be a practical way of protecting the liver and intestine during endotoxemia.
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Affiliation(s)
- Hiroshi Kono
- First Department of Surgery, Yamanashi Medical University, Yamanashi, Japan.
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Nanji AA, Jokelainen K, Fotouhinia M, Rahemtulla A, Thomas P, Tipoe GL, Su GL, Dannenberg AJ. Increased severity of alcoholic liver injury in female rats: role of oxidative stress, endotoxin, and chemokines. Am J Physiol Gastrointest Liver Physiol 2001; 281:G1348-56. [PMID: 11705739 DOI: 10.1152/ajpgi.2001.281.6.g1348] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Alcoholic liver injury is more severe and rapidly developing in women than men. To evaluate the reason(s) for these gender-related differences, we determined whether pathogenic mechanisms important in alcoholic liver injury in male rats were further upregulated in female rats. Male and age-matched female rats (7/group) were fed ethanol and a diet containing fish oil for 4 wk by intragastric infusion. Dextrose isocalorically replaced ethanol in control rats. We analyzed liver histopathology, lipid peroxidation, cytochrome P-450 (CYP)2E1 activity, nonheme iron, endotoxin, nuclear factor-kappa B (NF-kappa B) activation, and mRNA levels of cyclooxygenase-1 (COX-1) and COX-2, tumor necrosis factor-alpha (TNF-alpha), monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein-2 (MIP-2). Alcohol-induced liver injury was more severe in female vs. male rats. Female rats had higher endotoxin, lipid peroxidation, and nonheme iron levels and increased NF-kappa B activation and upregulation of the chemokines MCP-1 and MIP-2. CYP2E1 activity and TNF-alpha and COX-2 levels were similar in male and female rats. Remarkably, female rats fed fish oil and dextrose also showed necrosis and inflammation. Our findings in ethanol-fed rats suggest that increased endotoxemia and lipid peroxidation in females stimulate NF-kappa B activation and chemokine production, enhancing liver injury. TNF-alpha and COX-2 upregulation are probably important in causing liver injury but do not explain gender-related differences.
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Affiliation(s)
- A A Nanji
- Department of Pathology, The University of Hong Kong and Queen Mary Hospital, Hong Kong.
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Klurfeld DM. Synergy between medical and nutrient therapies: George Washington meets Rodney Dangerfield. J Am Coll Nutr 2001; 20:349S-353S. [PMID: 11603643 DOI: 10.1080/07315724.2001.10719167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Although medical therapies are widely accepted by health practitioners, sometimes without adequate testing, nutritional therapy is frequently looked upon uniformly as without merit. There are many reasons for this attitude. However, a substantial body of literature has accumulated that objectively demonstrates the value of adding nutritional therapy to the prevention or treatment of some diseases or specific risk factors for diseases. Examples of successful nutrition therapy that can be combined with medical management include treatment of hypertension, hyperlipidemia, intermittent claudication, osteoporosis, respiratory distress syndrome, and arthritis.
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Affiliation(s)
- D M Klurfeld
- Department of Nutrition and Food Science, Wayne State University, Detroit, Michigan 48202, USA.
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Cabré E, Rodríguez-Iglesias P, Caballería J, Quer JC, Sánchez-Lombraña JL, Parés A, Papo M, Planas R, Gassull MA. Short- and long-term outcome of severe alcohol-induced hepatitis treated with steroids or enteral nutrition: a multicenter randomized trial. Hepatology 2000; 32:36-42. [PMID: 10869286 DOI: 10.1053/jhep.2000.8627] [Citation(s) in RCA: 207] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Steroids are recommended in severe alcohol-induced hepatitis, but some data suggest that artificial nutrition could also be effective. We conducted a randomized trial comparing the short- and long-term effects of total enteral nutrition or steroids in these patients. A total of 71 patients (80% cirrhotic) were randomized to receive 40 mg/d prednisolone (n = 36) or enteral tube feeding (2,000 kcal/d) for 28 days (n = 35), and were followed for 1 year or until death. Side effects of treatment occurred in 5 patients on steroids and 10 on enteral nutrition (not significant). Eight enterally fed patients were prematurely withdrawn from the trial. Mortality during treatment was similar in both groups (9 of 36 vs. 11 of 35, intention-to-treat) but occurred earlier with enteral feeding (median 7 vs. 23 days; P =.025). Mortality during follow-up was higher with steroids (10 of 27 vs. 2 of 24 intention-to-treat; P =. 04). Seven steroid patients died within the first 1.5 months of follow-up. In contrast to total enteral nutrition (TEN), infections accounted for 9 of 10 follow-up deaths in the steroid group. In conclusion, enteral feeding does not seem to be worse than steroids in the short-term treatment of severe alcohol-induced hepatitis, although death occurs earlier with enteral nutrition. However, steroid therapy is associated with a higher mortality rate in the immediate weeks after treatment, mainly because of infections. A possible synergistic effect of both treatments should be investigated.
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