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Guo X, Zhou Q, Jin J, Lan F, Wen C, Li J, Yang N, Sun C. Hepatic steatosis is associated with dysregulated cholesterol metabolism and altered protein acetylation dynamics in chickens. J Anim Sci Biotechnol 2023; 14:108. [PMID: 37568219 PMCID: PMC10422840 DOI: 10.1186/s40104-023-00910-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 06/28/2023] [Indexed: 08/13/2023] Open
Abstract
BACKGROUND Hepatic steatosis is a prevalent manifestation of fatty liver, that has detrimental effect on the health and productivity of laying hens, resulting in economic losses to the poultry industry. Here, we aimed to systematically investigate the genetic regulatory mechanisms of hepatic steatosis in laying hens. METHODS Ninety individuals with the most prominent characteristics were selected from 686 laying hens according to the accumulation of lipid droplets in the liver, and were graded into three groups, including the control, mild hepatic steatosis and severe hepatic steatosis groups. A combination of transcriptome, proteome, acetylome and lipidome analyses, along with bioinformatics analysis were used to screen the key biological processes, modifications and lipids associated with hepatic steatosis. RESULTS The rationality of the hepatic steatosis grouping was verified through liver biochemical assays and RNA-seq. Hepatic steatosis was characterized by increased lipid deposition and multiple metabolic abnormalities. Integration of proteome and acetylome revealed that differentially expressed proteins (DEPs) interacted with differentially acetylated proteins (DAPs) and were involved in maintaining the metabolic balance in the liver. Acetylation alterations mainly occurred in the progression from mild to severe hepatic steatosis, i.e., the enzymes in the fatty acid oxidation and bile acid synthesis pathways were significantly less acetylated in severe hepatic steatosis group than that in mild group (P < 0.05). Lipidomics detected a variety of sphingolipids (SPs) and glycerophospholipids (GPs) were negatively correlated with hepatic steatosis (r ≤ -0.5, P < 0.05). Furthermore, the severity of hepatic steatosis was associated with a decrease in cholesterol and bile acid synthesis and an increase in exogenous cholesterol transport. CONCLUSIONS In addition to acquiring a global and thorough picture of hepatic steatosis in laying hens, we were able to reveal the role of acetylation in hepatic steatosis and depict the changes in hepatic cholesterol metabolism. The findings provides a wealth of information to facilitate a deeper understanding of the pathophysiology of fatty liver and contributes to the development of therapeutic strategies.
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Affiliation(s)
- Xiaoli Guo
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100193 China
| | - Qianqian Zhou
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100193 China
| | - Jiaming Jin
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100193 China
| | - Fangren Lan
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100193 China
| | - Chaoliang Wen
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100193 China
| | - Junying Li
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100193 China
| | - Ning Yang
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100193 China
| | - Congjiao Sun
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, 100193 China
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Investigation of the protective and therapeutic effects of thiamine in thioacetamide-induced liver injury. Biologia (Bratisl) 2022. [DOI: 10.1007/s11756-022-01062-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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3
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The Role and Mechanism of Oxidative Stress and Nuclear Receptors in the Development of NAFLD. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:6889533. [PMID: 34745420 PMCID: PMC8566046 DOI: 10.1155/2021/6889533] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 10/11/2021] [Indexed: 12/12/2022]
Abstract
The overproduction of reactive oxygen species (ROS) and consequent oxidative stress contribute to the pathogenesis of acute and chronic liver diseases. It is now acknowledged that nonalcoholic fatty liver disease (NAFLD) is characterized as a redox-centered disease due to the role of ROS in hepatic metabolism. However, the underlying mechanisms accounting for these alternations are not completely understood. Several nuclear receptors (NRs) are dysregulated in NAFLD, and have a direct influence on the expression of a set of genes relating to the progress of hepatic lipid homeostasis and ROS generation. Meanwhile, the NRs act as redox sensors in response to metabolic stress. Therefore, targeting NRs may represent a promising strategy for improving oxidation damage and treating NAFLD. This review summarizes the link between impaired lipid metabolism and oxidative stress and highlights some NRs involved in regulating oxidant/antioxidant turnover in the context of NAFLD, shedding light on potential therapies based on NR-mediated modulation of ROS generation and lipid accumulation.
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Yang J, Zhang Y, Pan Y, Sun C, Liu Z, Liu N, Fu Y, Li X, Li Y, Kong J. The Protective Effect of 1,25(OH) 2D 3 on Myocardial Function is Mediated via Sirtuin 3-Regulated Fatty Acid Metabolism. Front Cell Dev Biol 2021; 9:627135. [PMID: 33981701 PMCID: PMC8107292 DOI: 10.3389/fcell.2021.627135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 03/30/2021] [Indexed: 11/13/2022] Open
Abstract
Energy substrate imbalance is a major cause of cardiac dysfunction. Vitamin D/vitamin D receptor (VD/VDR) deficiency is involved in the pathogenesis of various cardiac diseases; however, the exact underlying mechanism remains unclear. The aim of this study was to investigate whether vitamin D modulates mitochondrial fatty acid oxidase via sirtuin 3 signaling to protect the myocardium. 1-Alpha-hydroxylase-defficient mice exhibited a high metabolic rate and lower myocardial contractility than wild-type mice. Sirtuin 3 upregulation was detected in high-fat diet-fed mice receiving vitamin D3 compared with that in high-fat diet-fed mice. Both sirtuin 3 blockade and knockout inhibited the VD/VDR-induced downregulation of fatty acid oxidase in myocardial mitochondria. VD/VDR suppressed fatty acid metabolism by upregulating sirtuin 3 and lowering mitochondrial fat uptake, thereby improving myocardial function and balancing energy substrates, rather than by altering fat endocytosis and exocytosis.
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Affiliation(s)
- Jingxin Yang
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yalin Zhang
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yiming Pan
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang, China
| | - Can Sun
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang, China
| | - Zuwang Liu
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang, China
| | - Ning Liu
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yu Fu
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xiaofeng Li
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang, China
| | - Ye Li
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang, China
| | - Juan Kong
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang, China
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5
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Liu J, Zhu J, Zhang X, Jia Y, Lee X, Gao Z. Hsa-miR-637 inhibits human hepatocyte proliferation by targeting Med1-interacting proteins. LIVER RESEARCH 2021. [DOI: 10.1016/j.livres.2021.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Goodson ML, Knotts TA, Campbell EL, Snyder CA, Young BM, Privalsky ML. Specific ablation of the NCoR corepressor δ splice variant reveals alternative RNA splicing as a key regulator of hepatic metabolism. PLoS One 2020; 15:e0241238. [PMID: 33104749 PMCID: PMC7588069 DOI: 10.1371/journal.pone.0241238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 10/10/2020] [Indexed: 12/15/2022] Open
Abstract
The NCoR corepressor plays critical roles in mediating transcriptional repression by both nuclear receptors and non-receptor transcription factors. Alternative mRNA splicing of NCoR produces a series of variants with differing molecular and biological properties. The NCoRω splice-variant inhibits adipogenesis whereas the NCoRδ splice-variant promotes it, and mice bearing a splice-specific knockout of NCoRω display enhanced hepatic steatosis and overall weight gain on a high fat diet as well as a greatly increased resistance to diet-induced glucose intolerance. We report here that the reciprocal NCoRδ splice-specific knock-out mice display the contrary phenotypes of reduced hepatic steatosis and reduced weight gain relative to the NCoRω-/- mice. The NCoRδ-/- mice also fail to demonstrate the strong resistance to diet-induced glucose intolerance exhibited by the NCoRω-/- animals. The NCoR δ and ω variants possess both unique and shared transcriptional targets, with expression of certain hepatic genes affected in opposite directions in the two mutants, others altered in one but not the other genotype, and yet others changed in parallel in both NCoRδ-/- and NCoRω-/- animals versus WT. Gene set expression analysis (GSEA) identified a series of lipid, carbohydrate, and amino acid metabolic pathways that are likely to contribute to their distinct steatosis and glucose tolerance phenotypes. We conclude that alternative-splicing of the NCoR corepressor plays a key role in the regulation of hepatic energy storage and utilization, with the NCoRδ and NCoRω variants exerting both opposing and shared functions in many aspects of this phenomenon and in the organism as a whole.
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Affiliation(s)
- Michael L. Goodson
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, California, United States of America
- * E-mail:
| | - Trina A. Knotts
- Department of Molecular Biosciences, School of Veterinary Medicine and Mouse Metabolic Phenotyping Center, Microbiome & Host Response Core, University of California at Davis, Davis, California, United States of America
| | - Elsie L. Campbell
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, California, United States of America
| | - Chelsea A. Snyder
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, California, United States of America
| | - Briana M. Young
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, California, United States of America
| | - Martin L. Privalsky
- Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, California, United States of America
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Neddylation of sterol regulatory element-binding protein 1c is a potential therapeutic target for nonalcoholic fatty liver treatment. Cell Death Dis 2020; 11:283. [PMID: 32332706 PMCID: PMC7181738 DOI: 10.1038/s41419-020-2472-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 12/27/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a risk factor for progression of steatohepatitis, liver cirrhosis, and liver cancer. Although pathological condition of NAFLD, which arises from an excessive accumulation of triglyceride in the liver, is accompanied by elevated sterol regulatory element-binding protein 1c (SREBP1c) level, it is largely unknown which factors are involved in the modification of SREBP1c. In this study, we discovered that neddylation of SREBP1c competes with its ubiquitination and stabilizes SREBP1c protein level, and eventually promotes hepatic steatosis. We also demonstrated that human homolog of mouse double minute 2 (HDM2) acts as an E3 neddylation ligase of SREBP1c. Further, treatment with the neddylation inhibitor, MLN4924, attenuates high-fat diet-induced hepatic steatosis by reducing the levels of SREBP1c protein and hepatic triglyceride. Our results indicate that the blockade of SREBP1c neddylation could be a novel approach in the defense against NAFLD.
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8
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Martin GG, Landrock D, Dangott LJ, McIntosh AL, Kier AB, Schroeder F. Human Liver Fatty Acid Binding Protein-1 T94A Variant, Nonalcohol Fatty Liver Disease, and Hepatic Endocannabinoid System. Lipids 2019; 53:27-40. [PMID: 29488637 DOI: 10.1002/lipd.12008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 10/26/2017] [Accepted: 10/31/2017] [Indexed: 12/16/2022]
Abstract
Hepatic endocannabinoids (EC) and their major binding/"chaperone" protein (i.e., liver fatty acid binding protein-1 [FABP1]) are associated with development of nonalcoholic fatty liver (NAFLD) in animal models and humans. Since expression of the highly prevalent human FABP1 T94A variant induces serum lipid accumulation, it is important to determine its impact on hepatic lipid accumulation and the EC system. This issue was addressed in livers from human subjects expressing only wild-type (WT) FABP1 T94T (TT genotype) or T94A variant (TC or CC genotype). WT FABP1 males had lower total lipids (both neutral cholesteryl esters, triacylglycerols) and phospholipids than females. WT FABP1 males' lower lipids correlated with lower levels of the N-acylethanolamide DHEA and 2-monoacylglycerols (2-MAG) (2-OG, 2-PG). T94A expression in males increased the hepatic total lipids (triacylglycerol, cholesteryl ester), which is consistent with their higher level of CB1-potentiating 2-OG and lower antagonistic EPEA. In contrast, in females, T94A expression did not alter the total lipids, neutral lipids, or phospholipids, which is attributable to the higher cannabinoid receptor-1 (CB1) agonist arachidonoylethanolamide (AEA) and its CB1-potentiator OEA being largely offset by reduced potentiating 2-OG and increased antagonistic EPEA. Taken together, these findings indicate that T94A-induced alterations in the hepatic EC system contribute at least in part to the hepatic accumulation of lipids associated with NAFLD, especially in males.
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Lawrence J Dangott
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843-2128, USA
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843-4466, USA
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9
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Guimarães J, Bargut TCL, Mandarim-de-Lacerda CA, Aguila MB. Medium-chain triglyceride reinforce the hepatic damage caused by fructose intake in mice. Prostaglandins Leukot Essent Fatty Acids 2019; 140:64-71. [PMID: 30553406 DOI: 10.1016/j.plefa.2018.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 11/06/2018] [Accepted: 11/08/2018] [Indexed: 01/16/2023]
Abstract
We aimed to investigate the effects of medium-chain triglyceride oil on the high fructose diet-provoked hepatic abnormalities in mice. We used C57bl/6 mice of 3-months-old divided into four groups for 12 weeks: control (C), control with MCT (C-MCT), fructose (F), and fructose with MCT (F-MCT). We investigated food and water intake, body mass, blood pressure, glucose tolerance, plasma and liver biochemistry, hepatic protein and gene expression. There were no changes in body mass, food intake and glucose tolerance among the groups. The F group presented increased water intake and blood pressure associated with hepatic steatosis and elevated de novo lipogenesis, beta-oxidation, mitochondrial biogenesis and inflammation in the liver. Surprisingly, the C-MCT group also showed hepatic steatosis and inflammation in the liver, and the F-MCT group had no exacerbations of fructose-induced abnormalities, showing marked hepatic steatosis, lipogenesis de novo and hepatic inflammation. The MCT oil groups also presented increased beta-oxidation and mitochondrial biogenesis. In conclusion, MCT oil showed detrimental hepatic effects and should be used with caution, especially in the presence of hepatic alterations.
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Affiliation(s)
- Janaina Guimarães
- Laboratory of Morphometry, Metabolism and Cardiovascular Diseases, Biomedical Center, Institute of Biology, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Carlos Alberto Mandarim-de-Lacerda
- Laboratory of Morphometry, Metabolism and Cardiovascular Diseases, Biomedical Center, Institute of Biology, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Marcia Barbosa Aguila
- Laboratory of Morphometry, Metabolism and Cardiovascular Diseases, Biomedical Center, Institute of Biology, State University of Rio de Janeiro, Rio de Janeiro, Brazil
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10
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Milligan S, Martin GG, Landrock D, McIntosh AL, Mackie JT, Schroeder F, Kier AB. Ablating both Fabp1 and Scp2/Scpx (TKO) induces hepatic phospholipid and cholesterol accumulation in high fat-fed mice. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:323-338. [PMID: 29307784 DOI: 10.1016/j.bbalip.2017.12.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 12/13/2017] [Accepted: 12/31/2017] [Indexed: 01/16/2023]
Abstract
Although singly ablating Fabp1 or Scp2/Scpx genes may exacerbate the impact of high fat diet (HFD) on whole body phenotype and non-alcoholic fatty liver disease (NAFLD), concomitant upregulation of the non-ablated gene, preference for ad libitum fed HFD, and sex differences complicate interpretation. Therefore, these issues were addressed in male and female mice ablated in both genes (Fabp1/Scp2/Scpx null or TKO) and pair-fed HFD. Wild-type (WT) males gained more body weight as fat tissue mass (FTM) and exhibited higher hepatic lipid accumulation than WT females. The greater hepatic lipid accumulation in WT males was associated with higher hepatic expression of enzymes in glyceride synthesis, higher hepatic bile acids, and upregulation of transporters involved in hepatic reuptake of serum bile acids. While TKO had little effect on whole body phenotype and hepatic bile acid accumulation in either sex, TKO increased hepatic accumulation of lipids in both, specifically phospholipid and cholesteryl esters in males and females and free cholesterol in females. TKO-induced increases in glycerides were attributed not only to complete loss of FABP1, SCP2 and SCPx, but also in part to sex-dependent upregulation of hepatic lipogenic enzymes. These data with WT and TKO mice pair-fed HFD indicate that: i) Sex significantly impacted the ability of HFD to increase body weight, induce hepatic lipid accumulation and increase hepatic bile acids; and ii) TKO exacerbated the HFD ability to induce hepatic lipid accumulation, regardless of sex, but did not significantly alter whole body phenotype in either sex.
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Affiliation(s)
- Sherrelle Milligan
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Gregory G Martin
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - Danilo Landrock
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Avery L McIntosh
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - John T Mackie
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - Ann B Kier
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA.
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11
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Ning R, Zhan Y, He S, Hu J, Zhu Z, Hu G, Yan B, Yang J, Liu W. Interleukin-6 Induces DEC1, Promotes DEC1 Interaction with RXRα and Suppresses the Expression of PXR, CAR and Their Target Genes. Front Pharmacol 2017; 8:866. [PMID: 29234281 PMCID: PMC5712319 DOI: 10.3389/fphar.2017.00866] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 11/09/2017] [Indexed: 12/17/2022] Open
Abstract
Inflammatory burden is a primary cellular event in many liver diseases, and the overall capacity of drug elimination is decreased. PXR (pregnane X receptor) and CAR (constitutive androstane receptor) are two master regulators of genes encoding drug-metabolizing enzymes and transporters. DEC1 (differentiated embryonic chondrocyte-expressed gene 1) is a ligand-independent transcription factor and reportedly is induced by many inflammatory cytokines including IL-6. In this study, we used primary hepatocytes (human and mouse) as well as HepG2 cell line and demonstrated that IL-6 increased DEC1 expression and decreased the expressions of PXR, CAR, and their target genes. Overexpression of DEC1 had similar effect as IL-6 on the expression of these genes, and knockdown of DEC1 reversed their downregulation by IL-6. Interestingly, neither IL-6 nor DEC1 altered the expression of RXRα, a common dimerization partner for many nuclear receptors including PXR and CAR. Instead, DEC1 was found to interact with RXRα and IL-6 enhanced the interaction. These results conclude that DEC1 uses diverse mechanisms of action and supports IL-6 downregulation of drug-elimination genes and their regulators.
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Affiliation(s)
- Rui Ning
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Yunran Zhan
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Shuangcheng He
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Jinhua Hu
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Zhu Zhu
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Gang Hu
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Bingfang Yan
- Pharmaceutical Sciences, Center for Pharmacogenomics and Molecular Therapy, University of Rhode Island, Kingston, RI, United States
| | - Jian Yang
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Wei Liu
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
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12
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Bozic M, Guzmán C, Benet M, Sánchez-Campos S, García-Monzón C, Gari E, Gatius S, Valdivielso JM, Jover R. Hepatocyte vitamin D receptor regulates lipid metabolism and mediates experimental diet-induced steatosis. J Hepatol 2016; 65:748-757. [PMID: 27245430 DOI: 10.1016/j.jhep.2016.05.031] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 05/03/2016] [Accepted: 05/23/2016] [Indexed: 01/10/2023]
Abstract
BACKGROUND & AIMS The pathogenesis and progression of non-alcoholic fatty liver disease (NAFLD) is still incompletely understood. Several nuclear receptors play a role in liver lipid metabolism and can promote hepatosteatosis, but the possible role of vitamin D receptor (VDR) in NAFLD has not been investigated. METHODS The expression of liver VDR was investigated in apolipoprotein E knockout (apoE(-/-)) mice on a high fat diet, in wild-type mice on methionine and choline deficient diet and in NAFLD patients with hepatosteatosis and non-alcoholic steatohepatitis. The relevance of VDR was assessed in apoE(-/-) mice by deletion of VDR or paricalcitol treatment and in human HepG2 cells by VDR transfection or silencing. The role of VDR in fibrosis was also determined in VDR knockout mice (VDR(-/-)) treated with thioacetamide. RESULTS Expression of liver VDR was markedly induced in two mouse models of NAFLD, as well as in patients with hepatosteatosis, but decreased in non-alcoholic steatohepatitis. VDR deletion in high fat diet-fed apoE(-/-) mice protected against fatty liver, dyslipidemia and insulin resistance, and caused a decrease in taurine-conjugated bile acids, but did not influence fibrosis by thioacetamide. apoE(-/-)VDR(-/-) mouse livers showed decreased gene expression of CD36, DGAT2, C/EBPα and FGF21, and increased expression of PNPLA2, LIPIN1 and PGC1α. Treatment of apoE(-/-) mice on high fat diet with paricalcitol had modest opposite effects on steatosis and gene expression. Finally, this set of genes showed concordant responses when VDR was overexpressed or silenced in HepG2 cells. CONCLUSIONS Induced hepatocyte VDR in NAFLD regulates key hepatic lipid metabolism genes and promotes high fat diet-associated liver steatosis. Therapeutic inhibition of liver VDR may reverse steatosis in early NAFLD. LAY SUMMARY The amount of vitamin D receptor is induced early in the livers of mice and humans when they develop non-alcoholic fatty liver disease. If the gene for the vitamin D receptor is deleted, hepatic lipid metabolism changes and mice do not accumulate fat in the liver. We conclude that the vitamin D receptor can contribute to the fatty liver disease promoted by a high fat diet.
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Affiliation(s)
- Milica Bozic
- Experimental Nephrology Laboratory, IRBLLEIDA, Lleida, Spain
| | - Carla Guzmán
- Experimental Hepatology Unit, IIS Hospital La Fe, Valencia, Spain
| | - Marta Benet
- Experimental Hepatology Unit, IIS Hospital La Fe, Valencia, Spain
| | - Sonia Sánchez-Campos
- Institute of Biomedicine (IBIOMED), University of León, Spain; CIBERehd, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Spain
| | - Carmelo García-Monzón
- Liver Research Unit, Hospital Santa Cristina, IIS Princesa, Madrid, Spain; CIBERehd, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Spain
| | - Eloi Gari
- Dep. Ciències Mèdiques Bàsiques, Universitat de Lleida, Spain
| | - Sonia Gatius
- Department of Pathology and Molecular Genetics, HUAV, IRBLLEIDA, Lleida, Spain
| | | | - Ramiro Jover
- Experimental Hepatology Unit, IIS Hospital La Fe, Valencia, Spain; CIBERehd, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Spain; Dep. Biochemistry and Molecular Biology, University of Valencia, Spain.
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13
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Notch1 deficiency decreases hepatic lipid accumulation by induction of fatty acid oxidation. Sci Rep 2016; 6:19377. [PMID: 26786165 PMCID: PMC4726366 DOI: 10.1038/srep19377] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 12/07/2015] [Indexed: 12/15/2022] Open
Abstract
Notch signaling pathways modulate various cellular processes, including cell proliferation, differentiation, adhesion, and communication. Recent studies have demonstrated that Notch1 signaling also regulates hepatic glucose production and lipid synthesis. However, the effect of Notch1 signaling on hepatic lipid oxidation has not yet been directly investigated. To define the function of Notch1 signaling in hepatic lipid metabolism, wild type mice and Notch1 deficient antisense transgenic (NAS) mice were fed a high-fat diet. High-fat diet -fed NAS mice exhibited a marked reduction in hepatic triacylglycerol accumulation compared with wild type obese mice. The improved fatty liver was associated with an increased expression of hepatic genes involved in fatty acid oxidation. However, lipogenic genes were not differentially expressed in the NAS liver, suggesting lipolytic-specific regulatory effects by Notch1 signaling. Expression of fatty acid oxidative genes and the rate of fatty acid oxidation were also increased by inhibition of Notch1 signaling in HepG2 cells. In addition, similar regulatory effects on lipid accumulation were observed in adipocytes. Taken together, these data show that inhibition of Notch1 signaling can regulate the expression of fatty acid oxidation genes and may provide therapeutic strategies in obesity-induced hepatic steatosis.
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El Kebbaj R, Andreoletti P, El Hajj HI, El Kharrassi Y, Vamecq J, Mandard S, Saih FE, Latruffe N, El Kebbaj MS, Lizard G, Nasser B, Cherkaoui-Malki M. Argan oil prevents down-regulation induced by endotoxin on liver fatty acid oxidation and gluconeogenesis and on peroxisome proliferator-activated receptor gamma coactivator-1α, (PGC-1α), peroxisome proliferator-activated receptor α (PPARα) and estrogen related receptor α (ERRα). BIOCHIMIE OPEN 2015; 1:51-59. [PMID: 29632829 PMCID: PMC5889474 DOI: 10.1016/j.biopen.2015.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 10/20/2015] [Indexed: 01/04/2023]
Abstract
In patients with sepsis, liver metabolism and its capacity to provide other organs with energetic substrates are impaired. This and many other pathophysiological changes seen in human patients are reproduced in mice injected with purified endotoxin (lipopolysaccharide, LPS). In the present study, down-regulation of genes involved in hepatic fatty acid oxidation (FAOx) and gluconeogenesis in mice exposed to LPS was challenged by nutritional intervention with Argan oil. Mice given a standard chow supplemented or not with either 6% (w/w) Argan oil (AO) or 6% (w/w) olive oil (OO) prior to exposure to LPS were explored for liver gene expressions assessed by mRNA transcript levels and/or enzyme activities. AO (or OO) food supplementation reveals that, in LPS-treated mice, hepatic expression of genes involved in FAOx and gluconeogenesis was preserved. This preventive protection might be related to the recovery of the gene expressions of nuclear receptors peroxisome proliferator-activated receptor α (PPARα) and estrogen related receptor α (ERRα) and their coactivator peroxisome proliferator-activated receptor gamma coactivator-1α, (PGC-1α). These preventive mechanisms conveyed by AO against LPS-induced metabolic dysregulation might add new therapeutic potentialities in the management of human sepsis. Argan oil prevents LPS-treated mice from liver dysregulation of FAOx and gluconeogenesis. Argan oil improves hepatic expression of PPARα and ERRα, and their coactivators PGC-1α and Lipin-1. New preventive mechanisms conveyed by Argan oil against LPS-induced metabolic dysregulation.
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Key Words
- ACADL, acyl CoA dehydrogenase long-chain
- ACADM, acyl CoA dehydrogenase medium-chain
- ACADS, acyl CoA dehydrogenase short-chain
- ACOX1, acyl-CoA oxidase 1
- AO, Argan oil
- Argan oil
- Beta-oxidation
- Coactivator
- ERRα, estrogen related receptor α
- G6PH, glucose-6-phosphatase
- Gluconeogenesis
- Glut2, glucose transporter 2
- Glut4, glucose transporter 4
- HNF-4α, hepatic nuclear factor-4α
- LPS, lipopolysaccharide
- Nuclear receptor
- OO, olive oil
- PEPCK, phospoenolpyruvate carboxykinase
- PGC-1α, peroxisome proliferator-activated receptor γ coactivator-1α
- PPARα, peroxisome proliferator-activated receptor α
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Affiliation(s)
- Riad El Kebbaj
- Univ. Bourgogne-Franche Comté, Laboratoire BioPeroxIL (Biochimie du Peroxysome, Inflammation et Métabolisme Lipidique), EA 7270, 21000 Dijon, France.,Laboratoir de Biochimie et Neurosciences, Faculté des Sciences et Techniques, Université Hassan I, BP 577, 26 000 Settat, Morocco.,Laboratoire des Sciences et Technologies de la Santé, Institut supérieur des sciences de la santé Université Hassan I, Route de Casablanca. 14 BP 539, 26 000 Settat, Morocco
| | - Pierre Andreoletti
- Univ. Bourgogne-Franche Comté, Laboratoire BioPeroxIL (Biochimie du Peroxysome, Inflammation et Métabolisme Lipidique), EA 7270, 21000 Dijon, France
| | - Hammam I El Hajj
- Univ. Bourgogne-Franche Comté, Laboratoire BioPeroxIL (Biochimie du Peroxysome, Inflammation et Métabolisme Lipidique), EA 7270, 21000 Dijon, France
| | - Youssef El Kharrassi
- Univ. Bourgogne-Franche Comté, Laboratoire BioPeroxIL (Biochimie du Peroxysome, Inflammation et Métabolisme Lipidique), EA 7270, 21000 Dijon, France.,Laboratoir de Biochimie et Neurosciences, Faculté des Sciences et Techniques, Université Hassan I, BP 577, 26 000 Settat, Morocco
| | - Joseph Vamecq
- INSERM and HMNO, CBP, CHRU Lille, 59037 Lille and RADEME EA 7364, Faculté de Médecine, Université de Lille 2, 59045 Lille, France
| | - Stéphane Mandard
- Lipness Team, INSERM, Research Center UMR866 and LabEx LipSTIC, Université de Bourgogne-Franche Comté, Dijon, France
| | - Fatima-Ezzahra Saih
- Univ. Bourgogne-Franche Comté, Laboratoire BioPeroxIL (Biochimie du Peroxysome, Inflammation et Métabolisme Lipidique), EA 7270, 21000 Dijon, France.,Laboratoir de Biochimie et Neurosciences, Faculté des Sciences et Techniques, Université Hassan I, BP 577, 26 000 Settat, Morocco
| | - Norbert Latruffe
- Univ. Bourgogne-Franche Comté, Laboratoire BioPeroxIL (Biochimie du Peroxysome, Inflammation et Métabolisme Lipidique), EA 7270, 21000 Dijon, France
| | - M'Hammed Saïd El Kebbaj
- Laboratoire de recherche sur les lipoprotéines et l'Athérosclérose, Faculté des Sciences Ben M'sik, Avenue Cdt Driss El Harti, BP 7955, Université Hassan II-Mohammedia-Casablanca, Morocco
| | - Gérard Lizard
- Univ. Bourgogne-Franche Comté, Laboratoire BioPeroxIL (Biochimie du Peroxysome, Inflammation et Métabolisme Lipidique), EA 7270, 21000 Dijon, France
| | - Boubker Nasser
- Laboratoir de Biochimie et Neurosciences, Faculté des Sciences et Techniques, Université Hassan I, BP 577, 26 000 Settat, Morocco
| | - Mustapha Cherkaoui-Malki
- Univ. Bourgogne-Franche Comté, Laboratoire BioPeroxIL (Biochimie du Peroxysome, Inflammation et Métabolisme Lipidique), EA 7270, 21000 Dijon, France
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15
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Martin GG, Atshaves BP, Landrock KK, Landrock D, Schroeder F, Kier AB. Loss of L-FABP, SCP-2/SCP-x, or both induces hepatic lipid accumulation in female mice. Arch Biochem Biophys 2015; 580:41-9. [PMID: 26116377 DOI: 10.1016/j.abb.2015.06.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 06/08/2015] [Accepted: 06/17/2015] [Indexed: 02/06/2023]
Abstract
Although roles for both sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) and liver fatty acid binding protein (L-FABP) have been proposed in hepatic lipid accumulation, individually ablating these genes has been complicated by concomitant alterations in the other gene product(s). For example, ablating SCP2/SCP-x induces upregulation of L-FABP in female mice. Therefore, the impact of ablating SCP-2/SCP-x (DKO) or L-FABP (LKO) individually or both together (TKO) was examined in female mice. Loss of SCP-2/SCP-x (DKO, TKO) more so than loss of L-FABP alone (LKO) increased hepatic total lipid and total cholesterol content, especially cholesteryl ester. Hepatic accumulation of nonesterified long chain fatty acids (LCFA) and phospholipids occurred only in DKO and TKO mice. Loss of SCP-2/SCP-x (DKO, TKO) increased serum total lipid primarily by increasing triglycerides. Altered hepatic level of proteins involved in cholesterol uptake, efflux, and/or secretion was observed, but did not compensate for the loss of L-FABP, SCP-2/SCP-x or both. However, synergistic responses were not seen with the combinatorial knock out animals-suggesting that inhibiting SCP-2/SCP-x is more correlative with hepatic dysfunction than L-FABP. The DKO- and TKO-induced hepatic accumulation of cholesterol and long chain fatty acids shared significant phenotypic similarities with non-alcoholic fatty liver disease (NAFLD).
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, United States
| | - Barbara P Atshaves
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, United States
| | - Kerstin K Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, United States
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States.
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16
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Cheng P, Li G, Yang SS, Liu R, Jin G, Zhou XY, Hu XG. Tumor suppressor Menin acts as a corepressor of LXRα to inhibit hepatic lipogenesis. FEBS Lett 2015; 589:3079-84. [PMID: 25962847 DOI: 10.1016/j.febslet.2015.04.049] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 04/03/2015] [Accepted: 04/23/2015] [Indexed: 01/07/2023]
Abstract
Menin, encoded by the MEN1 gene, was initially identified as a tumor suppressor for endocrine neoplasia. Our previous report showed that Menin enhances PPARα transactivity preventing triglyceride accumulation in the liver. Here, we further explore the role of Menin in liver steatosis. Transient transfection assays demonstrate that Menin inhibits the transcriptional activity of nuclear receptor liver X receptor α (LXRα). Accordingly, Menin overexpression results in reduced expression of LXRα target genes, such as lipogenic enzymes including SREBP-1c, FASN and SCD-1. Co-immunoprecipitation assays revealed physical interaction between Menin and LXRα. Collectively, our data suggest that Menin acts as a novel corepressor of LXRα and functions as a negative regulator of hepatic lipogenesis.
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Affiliation(s)
- Peng Cheng
- Department of Hepatobiliary Pancreatic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Gang Li
- Department of Hepatobiliary Pancreatic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Sheng Sheng Yang
- Department of Biochemistry and Molecular Biology, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Rui Liu
- Department of Hepatobiliary Pancreatic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
| | - Gang Jin
- Department of Hepatobiliary Pancreatic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China.
| | - Xu Yu Zhou
- Department of Hepatobiliary Pancreatic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China.
| | - Xian Gui Hu
- Department of Hepatobiliary Pancreatic Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, People's Republic of China
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17
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Wang Y, Tong J, Chang B, Wang BF, Zhang D, Wang BY. Effects of ethanol on the expression of caveolin-1 in HepG2 cells. Mol Med Rep 2015; 11:4409-13. [PMID: 25651074 DOI: 10.3892/mmr.2015.3296] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 06/09/2014] [Indexed: 11/05/2022] Open
Abstract
This study aimed to investigate the effects of ethanol on the expression of caveolin‑1 (CAV‑1) in HepG2 hepatocarcinoma cells. Ethanol‑treated HepG2 cells were investigated using the in vitro model to determine whether ethanol can influence the expression of CAV‑1. Cell viability was measured using the colorimetric 3‑(4, 5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Expression of CAV‑1 was detected using western blot analysis. Quantitative PCR (qPCR) was used to determine CAV‑1 mRNA levels. The distribution of CAV‑1 in HepG2 cells was analyzed using immunofluorescence. The MTT assay results revealed that cell viability was not altered at ethanol concentrations of <1.0%, while ethanol concentrations >1.0% caused cell shedding, but not cell fragmentation. Western blot analysis showed significant differences in the levels of CAV‑1 expression between the control group and the 1.0% ethanol‑treated group at 6, 12 and 24 h (all P<0.05). qPCR showed significant differences in the expression levels of caveolin‑1 mRNA between the control group and the 1.0% ethanol‑treated group at 6 h, 12 h and 24 h (all P<0.05). Immunofluorescence demonstrated that CAV‑1 was distributed discontinuously at the boundaries of HepG2 cells. The results indicate that ethanol may increase the expression of CAV‑1 in HepG2 cells.
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Affiliation(s)
- Ying Wang
- Department of Gastroenterology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Jing Tong
- Department of Gastroenterology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Bing Chang
- Department of Gastroenterology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Bai-Fang Wang
- Department of Gastroenterology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Dai Zhang
- Department of Gastroenterology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Bing-Yuan Wang
- Department of Gastroenterology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
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18
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Friedman SL, Quigley EMM, Sharkey KA, Sung JJY, Whitcomb DC. The past 10 years of gastroenterology and hepatology-reflections and predictions. Nat Rev Gastroenterol Hepatol 2014; 11:692-700. [PMID: 25291429 DOI: 10.1038/nrgastro.2014.167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In November 2004, the very first issue of this journal featured articles on the pathogenesis of ulcerative colitis, mechanisms leading to chronic pancreatitis, and treatment of recurrent Clostridium-difficile-associated diarrhoea. Although those topics might seem familiar, much has changed in the intervening years in our understanding, diagnosis and treatment of many different diseases across the field of gastroenterology and hepatology. Nonetheless, many challenges remain. Here, we have asked five of our Advisory Board members-international experts across different subspecialties in gastroenterology and hepatology-to reflect on the progress and frustrations of the past 10 years. They also comment on where effort and money should be invested now, as well as their predictions for progress in the next 10 years.
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Affiliation(s)
- Scott L Friedman
- Division of Liver Disease, Box 1123, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Room 11-70C, New York, NY 10029-6574, USA
| | - Eamonn M M Quigley
- Division of Gastroenterology and Hepatology, Houston Methodist Hospital, 6550 Fannin Street, SM 1001, Houston, TX 77030, USA
| | - Keith A Sharkey
- Hotchkiss Brain Institute and Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| | - Joseph J Y Sung
- University Administration Building, The Chinese University of Hong Kong, 1/F, Room 101, Shatin, NT, Hong Kong SAR, The People's Republic of China
| | - David C Whitcomb
- Department of Medicine, Cell Biology &Molecular Physiology and Human Genetics, University of Pittsburgh and UPMC, Room 401.4, 3708 Fifth Avenue, Pittsburgh, PA 15231, USA
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19
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Lonardo A, Adinolfi LE, Restivo L, Ballestri S, Romagnoli D, Baldelli E, Nascimbeni F, Loria P. Pathogenesis and significance of hepatitis C virus steatosis: An update on survival strategy of a successful pathogen. World J Gastroenterol 2014; 20:7089-7103. [PMID: 24966582 PMCID: PMC4064057 DOI: 10.3748/wjg.v20.i23.7089] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 04/03/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) is a successful pathogen on the grounds that it exploits its host’s metabolism to build up viral particles; moreover it favours its own survival by inducing chronic disease and the development of specific anatomic changes in the infected organ. Steatosis, therefore, is associated with HCV infection by necessity rather than by chance alone. Approximately 6% of HCV patients have steatohepatitis. Interestingly, HCV steatosis occurs in the setting of multiple metabolic abnormalities (hyperuricemia, reversible hypocholesterolemia, insulin resistance, arterial hypertension and expansion of visceral adipose tissue) collectively referred to as “hepatitis C-associated dysmetabolic syndrome” (HCADS). General, nonalcoholic fatty liver disease (NAFLD)-like, mechanisms of steatogenesis (including increased availability of lipogenic substrates and de novo lipogenesis; decreased oxidation of fatty substrates and export of fatty substrates) are shared by all HCV genotypes. However, genotype 3 seemingly amplifies such steatogenic molecular mechanisms reported to occur in NAFLD via more profound changes in microsomal triglyceride transfer protein; peroxisome proliferator-activated receptor alpha; sterol regulatory element-binding proteins and phosphatase and tensin homologue. HCV steatosis has a remarkable clinical impact in as much as it is an acknowledged risk factor for accelerated fibrogenesis; for impaired treatment response to interferon and ribavirin; and development of hepatocellular carcinoma. Recent data, moreover, suggest that HCV-steatosis contributes to premature atherogenesis via both direct and indirect mechanisms. In conclusion, HCV steatosis fulfills all expected requirements necessary to perpetuate the HCV life cycle. A better understanding of the physiology of HCADS will likely result in a more successful handling of disease with improved antiviral success rates.
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Misra P, Reddy JK. Peroxisome proliferator-activated receptor-α activation and excess energy burning in hepatocarcinogenesis. Biochimie 2014; 98:63-74. [DOI: 10.1016/j.biochi.2013.11.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 11/14/2013] [Indexed: 01/23/2023]
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21
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Jia Y, Viswakarma N, Reddy JK. Med1 subunit of the mediator complex in nuclear receptor-regulated energy metabolism, liver regeneration, and hepatocarcinogenesis. Gene Expr 2014; 16:63-75. [PMID: 24801167 PMCID: PMC4093800 DOI: 10.3727/105221614x13919976902219] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Several nuclear receptors regulate diverse metabolic functions that impact on critical biological processes, such as development, differentiation, cellular regeneration, and neoplastic conversion. In the liver, some members of the nuclear receptor family, such as peroxisome proliferator-activated receptors (PPARs), constitutive androstane receptor (CAR), farnesoid X receptor (FXR), liver X receptor (LXR), pregnane X receptor (PXR), glucocorticoid receptor (GR), and others, regulate energy homeostasis, the formation and excretion of bile acids, and detoxification of xenobiotics. Excess energy burning resulting from increases in fatty acid oxidation systems in liver generates reactive oxygen species, and the resulting oxidative damage influences liver regeneration and liver tumor development. These nuclear receptors are important sensors of exogenous activators as well as receptor-specific endogenous ligands. In this regard, gene knockout mouse models revealed that some lipid-metabolizing enzymes generate PPARα-activating ligands, while others such as ACOX1 (fatty acyl-CoA oxidase1) inactivate these endogenous PPARα activators. In the absence of ACOX1, the unmetabolized ACOX1 substrates cause sustained activation of PPARα, and the resulting increase in energy burning leads to hepatocarcinogenesis. Ligand-activated nuclear receptors recruit the multisubunit Mediator complex for RNA polymerase II-dependent gene transcription. Evidence indicates that the Med1 subunit of the Mediator is essential for PPARα, PPARγ, CAR, and GR signaling in liver. Med1 null hepatocytes fail to respond to PPARα activators in that these cells do not show induction of peroxisome proliferation and increases in fatty acid oxidation enzymes. Med1-deficient hepatocytes show no increase in cell proliferation and do not give rise to liver tumors. Identification of nuclear receptor-specific coactivators and Mediator subunits should further our understanding of the complexities of metabolic diseases associated with increased energy combustion in liver.
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Affiliation(s)
- Yuzhi Jia
- *Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
| | - Navin Viswakarma
- †Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Maywood, IL, USA
| | - Janardan K. Reddy
- *Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
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22
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Serviddio G, Bellanti F, Vendemiale G. Free radical biology for medicine: learning from nonalcoholic fatty liver disease. Free Radic Biol Med 2013; 65:952-968. [PMID: 23994574 DOI: 10.1016/j.freeradbiomed.2013.08.174] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 08/20/2013] [Accepted: 08/20/2013] [Indexed: 02/07/2023]
Abstract
Reactive oxygen species, when released under controlled conditions and limited amounts, contribute to cellular proliferation, senescence, and survival by acting as signaling intermediates. In past decades there has been an epidemic diffusion of nonalcoholic fatty liver disease (NAFLD) that represents the result of the impairment of lipid metabolism, redox imbalance, and insulin resistance in the liver. To date, most studies and reviews have been focused on the molecular mechanisms by which fatty liver progresses to steatohepatitis, but the processes leading toward the development of hepatic steatosis in NAFLD are not fully understood yet. Several nuclear receptors, such as peroxisome proliferator-activated receptors (PPARs) α/γ/δ, PPARγ coactivators 1α and 1β, sterol-regulatory element-binding proteins, AMP-activated protein kinase, liver-X-receptors, and farnesoid-X-receptor, play key roles in the regulation of lipid homeostasis during the pathogenesis of NAFLD. These nuclear receptors may act as redox sensors and may modulate various metabolic pathways in response to specific molecules that act as ligands. It is conceivable that a redox-dependent modulation of lipid metabolism, nuclear receptor-mediated, could cause the development of hepatic steatosis and insulin resistance. Thus, this network may represent a potential therapeutic target for the treatment and prevention of hepatic steatosis and its progression to steatohepatitis. This review summarizes the redox-dependent factors that contribute to metabolism alterations in fatty liver with a focus on the redox control of nuclear receptors in normal liver as well as in NAFLD.
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Affiliation(s)
- Gaetano Serviddio
- C.U.R.E. Centre for Liver Disease Research and Treatment, Institute of Internal Medicine, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy.
| | - Francesco Bellanti
- C.U.R.E. Centre for Liver Disease Research and Treatment, Institute of Internal Medicine, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
| | - Gianluigi Vendemiale
- C.U.R.E. Centre for Liver Disease Research and Treatment, Institute of Internal Medicine, Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy
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Affiliation(s)
- Ramon Bataller
- Departments of Medicine and Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Bin Gao
- Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
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24
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El Kebbaj R, Kamouni SE, El Hajj HI, Andreoletti P, Gresti J, Latruffe N, El Kebbaj MS, Vamecq J, Lizard G, Nasser B, Cherkaoui-Malki M. Modulation of peroxisomes abundance by argan oil and lipopolysaccharides in acyl-CoA oxidase 1-deficient fibroblasts. Health (London) 2013. [DOI: 10.4236/health.2013.51009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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