151
|
Lake AD, Chaput AL, Novak P, Cherrington NJ, Smith CL. Transcription factor binding site enrichment analysis predicts drivers of altered gene expression in nonalcoholic steatohepatitis. Biochem Pharmacol 2016; 122:62-71. [PMID: 27836672 PMCID: PMC5129657 DOI: 10.1016/j.bcp.2016.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/04/2016] [Indexed: 12/21/2022]
Abstract
The molecular mechanisms behind the transition from simple steatosis to nonalcoholic steatohepatitis (NASH) in nonalcoholic fatty liver disease (NAFLD) are not clearly understood. This hinders development of effective therapies for treatment and prevention of NASH. In this study expression profiling data from normal, steatosis, and NASH human livers were used to predict transcription factors that are misregulated as mechanistic features of NAFLD progression. Previously-published human NAFLD gene expression profiling data from normal, steatosis, and NASH livers were subjected to transcription factor binding site enrichment analysis. Selected transcription factors that bind enriched transcription factor binding sites were analyzed for changes in expression. Distinct transcription factor binding sites were enriched in genes significantly up- or down-regulated in NASH livers. Those enriched in up-regulated genes were bound by transcription factors such as FOXA, CEBP, and HNF1 family members, while those enriched in down-regulated genes were bound by nuclear receptors involved in xenobiotic sensing and lipid metabolism. Levels of mRNA and protein for selected transcription factors were significantly changed during disease progression. The study indicates that NAFLD progression involves changes in activity or expression of transcription factors that regulate genes involved in hepatic processes known to be altered in NASH. Transcription factors such as PPAR receptors, FoxA family members, and HNF4A might be targeted therapeutically to prevent NAFLD progression.
Collapse
Affiliation(s)
- April D Lake
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
| | - Alexandria L Chaput
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
| | - Petr Novak
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States; Biology Centre ASCR, Institute of Plant Molecular Biology, Branisovska 31, Ceske Budejovice CZ-37005, Czech Republic
| | - Nathan J Cherrington
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
| | - Catharine L Smith
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States.
| |
Collapse
|
152
|
Li J, Wang Y, Matye DJ, Chavan H, Krishnamurthy P, Li F, Li T. Sortilin 1 Modulates Hepatic Cholesterol Lipotoxicity in Mice via Functional Interaction with Liver Carboxylesterase 1. J Biol Chem 2016; 292:146-160. [PMID: 27881673 DOI: 10.1074/jbc.m116.762005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/19/2016] [Indexed: 12/13/2022] Open
Abstract
The liver plays a key role in cholesterol metabolism. Impaired hepatic cholesterol homeostasis causes intracellular free cholesterol accumulation and hepatocyte injury. Sortilin 1 (SORT1) is a lysosomal trafficking receptor that was identified by genome-wide association studies (GWAS) as a novel regulator of cholesterol metabolism in humans. Here we report that SORT1 deficiency protected against cholesterol accumulation-induced liver injury and inflammation in mice. Using an LC-MS/MS-based proteomics approach, we identified liver carboxylesterase 1 (CES1) as a novel SORT1-interacting protein. Mechanistic studies further showed that SORT1 may regulate CES1 lysosomal targeting and degradation and that SORT1 deficiency resulted in higher liver CES1 protein abundance. Previous studies have established an important role of hepatic CES1 in promoting intracellular cholesterol mobilization, cholesterol efflux, and bile acid synthesis. Consistently, high cholesterol atherogenic diet-challenged Sort1 knock-out mice showed less hepatic free cholesterol accumulation, increased bile acid synthesis, decreased biliary cholesterol secretion, and the absence of gallstone formation. SORT1 deficiency did not alter hepatic ceramide and fatty acid metabolism in high cholesterol atherogenic diet-fed mice. Finally, knockdown of liver CES1 in mice markedly increased the susceptibility to high cholesterol diet-induced liver injury and abolished the protective effect against cholesterol lipotoxicity in Sort1 knock-out mice. In summary, this study identified a novel SORT1-CES1 axis that regulates cholesterol-induced liver injury, which provides novel insights that improve our current understanding of the molecular links between SORT1 and cholesterol metabolism. This study further suggests that therapeutic inhibition of SORT1 may be beneficial in improving hepatic cholesterol homeostasis in metabolic and inflammatory liver diseases.
Collapse
Affiliation(s)
- Jibiao Li
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| | - Yifeng Wang
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| | - David J Matye
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| | - Hemantkumar Chavan
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| | - Partha Krishnamurthy
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| | - Feng Li
- the Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Tiangang Li
- From the Department of Pharmacology, Toxicology and Therapeutics, Kansas University Medical Center, Kansas City, Kansas 66160 and
| |
Collapse
|
153
|
Wang CM, Yuan RS, Zhuang WY, Sun JH, Wu JY, Li H, Chen JG. Schisandra polysaccharide inhibits hepatic lipid accumulation by downregulating expression of SREBPs in NAFLD mice. Lipids Health Dis 2016; 15:195. [PMID: 27852305 PMCID: PMC5112637 DOI: 10.1186/s12944-016-0358-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 10/28/2016] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Hepatoprotective effects of Chinese herbal medicine Schisandra Chinensis (Schisandra) have been widely investigated. However, most studies were focused on its lignan extracts. We investigated the effects of Schisandra polysaccharide (SCP) in a mouse model of non-alcoholic fatty liver disease (NAFLD), and studied its effect on sterol regulatory element binding proteins (SREBPs) and the related genes. METHODS The mouse model of NAFLD was established by feeding mice with a high-fat diet for 16 weeks. Effect of SCP-treatment (100 mg/kg, once daily for 12 weeks) on biochemical parameters and liver histopathology was assessed. Relative levels of sterol regulatory element-binding proteins (SREBPs) and their gene expressions were determined by quantitative real-time polymerase chain reaction and Western Blot. RESULTS SCP significantly reduced the liver index by 12.0%. Serum levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol, alanine aminotransferase and aspartate aminotransferase were decreased by 31.3, 28.3, 42.8, 20.1 and 15.5%, respectively. Serum high-density lipoprotein cholesterol was increased by 26.9%. Further, SCP lowered hepatic TC and TG content by 27.0% and 28.3%, respectively, and alleviated fatty degeneration and necrosis of liver cells. A significant downregulation of mRNA and protein expressions of hepatic lipogenesis genes, SREBP-1c, fatty acid synthase and acetyl-CoA carboxylase, and the mRNA expression of liver X receptor α (LXRα) was observed in NAFLD mice treated with SCP. SCP also significantly reduced the hepatic expression of SREBP-2 and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). CONCLUSION These findings demonstrate the hepatoprotective effects of SCP in a mouse model of NAFLD; the effects may be mediated via downregulation of LXRα/SREBP-1c/FAS/ACC and SREBP-2/HMGCR signaling pathways in the liver.
Collapse
Affiliation(s)
- Chun-Mei Wang
- Department of Pharmacology, College of Pharmacy, Beihua University, No. 3999 Binjiang East Road, Fengman District, Jilin City, Jilin Province, People's Republic of China
| | - Rong-Shuang Yuan
- Department of Pharmacology, College of Pharmacy, Beihua University, No. 3999 Binjiang East Road, Fengman District, Jilin City, Jilin Province, People's Republic of China
| | - Wen-Yue Zhuang
- Department of Molecular Biology, College of Laboratory Medicine, Beihua University, Jilin, Jilin, 132013, China
| | - Jing-Hui Sun
- Department of Pharmacology, College of Pharmacy, Beihua University, No. 3999 Binjiang East Road, Fengman District, Jilin City, Jilin Province, People's Republic of China
| | - Jin-Ying Wu
- Department of Pharmacology, College of Pharmacy, Beihua University, No. 3999 Binjiang East Road, Fengman District, Jilin City, Jilin Province, People's Republic of China
| | - He Li
- Department of Pharmacology, College of Pharmacy, Beihua University, No. 3999 Binjiang East Road, Fengman District, Jilin City, Jilin Province, People's Republic of China.
| | - Jian-Guang Chen
- Department of Pharmacology, College of Pharmacy, Beihua University, No. 3999 Binjiang East Road, Fengman District, Jilin City, Jilin Province, People's Republic of China.
| |
Collapse
|
154
|
Ducheix S, Vegliante MC, Villani G, Napoli N, Sabbà C, Moschetta A. Is hepatic lipogenesis fundamental for NAFLD/NASH? A focus on the nuclear receptor coactivator PGC-1β. Cell Mol Life Sci 2016; 73:3809-22. [PMID: 27522544 PMCID: PMC11108573 DOI: 10.1007/s00018-016-2331-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 08/04/2016] [Indexed: 02/07/2023]
Abstract
Non-alcoholic fatty liver diseases are the hepatic manifestation of metabolic syndrome. According to the classical pattern of NAFLD progression, de novo fatty acid synthesis has been incriminated in NAFLD progression. However, this hypothesis has been challenged by the re-evaluation of NAFLD development mechanisms together with the description of the role of lipogenic genes in NAFLD and with the recent observation that PGC-1β, a nuclear receptor/transcription factor coactivator involved in the transcriptional regulation of lipogenesis, displays protective effects against NAFLD/NASH progression. In this review, we focus on the implication of lipogenesis and triglycerides synthesis on the development of non-alcoholic fatty liver diseases and discuss the involvement of these pathways in the protective role of PGC-1β toward these hepatic manifestations.
Collapse
Affiliation(s)
- Simon Ducheix
- Clinica Medica "Cesare Frugoni", Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, 70124, Bari, Italy
- IRCCS Istituto Tumori "Giovanni Paolo II", Viale O. Flacco 65, 70124, Bari, Italy
| | - Maria Carmela Vegliante
- Clinica Medica "Cesare Frugoni", Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Gaetano Villani
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Nicola Napoli
- Clinica Medica "Cesare Frugoni", Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Carlo Sabbà
- Clinica Medica "Cesare Frugoni", Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Antonio Moschetta
- Clinica Medica "Cesare Frugoni", Department of Interdisciplinary Medicine, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, 70124, Bari, Italy.
- IRCCS Istituto Tumori "Giovanni Paolo II", Viale O. Flacco 65, 70124, Bari, Italy.
| |
Collapse
|
155
|
Caligiuri A, Gentilini A, Marra F. Molecular Pathogenesis of NASH. Int J Mol Sci 2016; 17:ijms17091575. [PMID: 27657051 PMCID: PMC5037841 DOI: 10.3390/ijms17091575] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 09/05/2016] [Accepted: 09/07/2016] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic steatohepatitis (NASH) is the main cause of chronic liver disease in the Western world and a major health problem, owing to its close association with obesity, diabetes, and the metabolic syndrome. NASH progression results from numerous events originating within the liver, as well as from signals derived from the adipose tissue and the gastrointestinal tract. In a fraction of NASH patients, disease may progress, eventually leading to advanced fibrosis, cirrhosis and hepatocellular carcinoma. Understanding the mechanisms leading to NASH and its evolution to cirrhosis is critical to identifying effective approaches for the treatment of this condition. In this review, we focus on some of the most recent data reported on the pathogenesis of NASH and its fibrogenic progression, highlighting potential targets for treatment or identification of biomarkers of disease progression.
Collapse
Affiliation(s)
- Alessandra Caligiuri
- Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi di Firenze, Firenze 50121, Italy.
| | - Alessandra Gentilini
- Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi di Firenze, Firenze 50121, Italy.
| | - Fabio Marra
- Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi di Firenze, Firenze 50121, Italy.
| |
Collapse
|
156
|
Vega-Badillo J, Gutiérrez-Vidal R, Hernández-Pérez HA, Villamil-Ramírez H, León-Mimila P, Sánchez-Muñoz F, Morán-Ramos S, Larrieta-Carrasco E, Fernández-Silva I, Méndez-Sánchez N, Tovar AR, Campos-Pérez F, Villarreal-Molina T, Hernández-Pando R, Aguilar-Salinas CA, Canizales-Quinteros S. Hepatic miR-33a/miR-144 and their target gene ABCA1 are associated with steatohepatitis in morbidly obese subjects. Liver Int 2016; 36:1383-91. [PMID: 26945479 DOI: 10.1111/liv.13109] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 02/26/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIM Abnormal cholesterol metabolism may contribute to the pathogenesis of non-alcoholic steatohepatitis (NASH) and fibrosis. miR-33 and miR-144 regulate adenosine triphosphate binding cassette transporter (ABCA1) and other target genes involved in cholesterol efflux, fatty acid oxidation and inflammation. We explored relationships between non-alcoholic fatty liver disease (NAFLD) and the hepatic expression of ABCA1/ABCG1, as well as other target genes regulated by miR-33 (carnitine O-octanoyltransferase, CROT and hydroxyacyl-CoA-dehydrogenase β-subunit, HADHB) and miR-144 (toll-like receptor-2, TLR2). Moreover, we evaluated whether the expression of these genes is correlated with miR-33a/b and miR-144 expression in Mexican individuals with morbid obesity. METHODS Eighty-four morbidly obese subjects undergoing bariatric surgery were included in this study. Liver biopsies were obtained to measure hepatic triglyceride and free cholesterol contents, as well as ABCA1, ABCG1, CROT, HADHB, TLR2, miR-33a/b and miR-144 expression. RESULTS Hepatic free cholesterol content was significantly increased in NASH as compared to non-NASH subjects, while ABCA1 and ABCG1 protein levels significantly decreased with NASH and fibrosis progression. The relative expression of miR-33a and miR-144 correlated inversely with ABCA1 but not with ABCG1 protein levels. Moreover, both miRNAs increased significantly in NASH individuals. miR-33 target genes CROT and HADHB correlated inversely with miR-33a. However, the expression of these genes was not associated with NASH. CONCLUSIONS miR-33a/144 and their target gene ABCA1 may contribute to the pathogenesis of NASH in morbidly obese subjects.
Collapse
Affiliation(s)
- Joel Vega-Badillo
- Programa de Doctorado en Ciencias Bioquímicas, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM/Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, Mexico
| | - Roxana Gutiérrez-Vidal
- Programa de Doctorado en Ciencias Bioquímicas, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM/Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, Mexico
| | - Hugo A Hernández-Pérez
- Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM/Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, Mexico
| | - Hugo Villamil-Ramírez
- Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM/Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, Mexico
| | - Paola León-Mimila
- Programa de Doctorado en Ciencias Bioquímicas, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM/Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, Mexico
| | - Fausto Sánchez-Muñoz
- Departamento de Inmunología, Instituto Nacional de Cardiología "Ignacio Chávez" (INCICh), Mexico City, Mexico
| | - Sofía Morán-Ramos
- Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM/Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, Mexico
| | - Elena Larrieta-Carrasco
- Departamento de Gastroenterología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ), Mexico City, Mexico
| | - Itzel Fernández-Silva
- Clínica Integral de Cirugía para la Obesidad y Enfermedades Metabólicas, Hospital General "Dr. Rubén Leñero", Mexico City, Mexico
| | - Nahúm Méndez-Sánchez
- Unidad de Investigación del Hígado, Fundación Clínica Médica Sur, Mexico City, Mexico
| | - Armando R Tovar
- Departamento Fisiología de la Nutrición, INCMNSZ, Mexico City, Mexico
| | - Francisco Campos-Pérez
- Clínica Integral de Cirugía para la Obesidad y Enfermedades Metabólicas, Hospital General "Dr. Rubén Leñero", Mexico City, Mexico
| | | | | | | | - Samuel Canizales-Quinteros
- Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM/Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, Mexico
| |
Collapse
|
157
|
Walenbergh SMA, Shiri-Sverdlov R. Cholesterol is a significant risk factor for non-alcoholic steatohepatitis. Expert Rev Gastroenterol Hepatol 2016; 9:1343-6. [PMID: 26395315 DOI: 10.1586/17474124.2015.1092382] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Non-alcoholic steatohepatitis (NASH) is characterized by hepatic lipid accumulation (steatosis) and inflammation (steatohepatitis). Currently, the exact underlying mechanisms leading to hepatic inflammation remain incompletely understood and therefore therapy options are poor. Analogous to the predominant metabolic risk factor for the metabolic syndrome, NASH patients often display diet-induced dyslipidemia and are therefore also at high risk for cardiovascular disease. Higher lipid levels, in general, are also widely associated with the production of reactive oxygen species during oxidation. However, the exact contribution of the specific type of lipids to hepatic inflammation still remains unclear. In this editorial, we aim to show that cholesterol, in addition to triglycerides and free fatty acids, is an important risk factor in NASH disease pathogenesis. Developing a better understanding of the contribution of lipids underlying NASH pathogenesis is essential for creating effective therapies against this prevalent disease.
Collapse
Affiliation(s)
- Sofie M A Walenbergh
- a Department of Molecular Genetics, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
| | - Ronit Shiri-Sverdlov
- a Department of Molecular Genetics, School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
| |
Collapse
|
158
|
Liver Cholesterol Overload Aggravates Obstructive Cholestasis by Inducing Oxidative Stress and Premature Death in Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:9895176. [PMID: 27635189 PMCID: PMC5011220 DOI: 10.1155/2016/9895176] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/13/2016] [Indexed: 12/14/2022]
Abstract
Nonalcoholic steatohepatitis is one of the leading causes of liver disease. Dietary factors determine the clinical presentation of steatohepatitis and can influence the progression of related diseases. Cholesterol has emerged as a critical player in the disease and hence consumption of cholesterol-enriched diets can lead to a progressive form of the disease. The aim was to investigate the impact of liver cholesterol overload on the progression of the obstructive cholestasis in mice subjected to bile duct ligation surgery. Mice were fed with a high cholesterol diet for two days and then were subjected to surgery procedure; histological, biochemical, and molecular analyses were conducted to address the effect of cholesterol in liver damage. Mice under the diet were more susceptible to damage. Results show that cholesterol fed mice exhibited increased apoptosis and oxidative stress as well as reduction in cell proliferation. Mortality following surgery was higher in HC fed mice. Liver cholesterol impairs the repair of liver during obstructive cholestasis and aggravates the disease with early fatal consequences; these effects were strongly associated with oxidative stress.
Collapse
|
159
|
Mota M, Banini BA, Cazanave SC, Sanyal AJ. Molecular mechanisms of lipotoxicity and glucotoxicity in nonalcoholic fatty liver disease. Metabolism 2016; 65:1049-61. [PMID: 26997538 PMCID: PMC4931958 DOI: 10.1016/j.metabol.2016.02.014] [Citation(s) in RCA: 364] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 02/05/2016] [Accepted: 02/23/2016] [Indexed: 12/21/2022]
Abstract
The exposure of hepatocytes to high concentrations of lipids and carbohydrates and the ensuing hepatocellular injury are termed lipotoxicity and glucotoxicity, respectively. A common denominator is metabolic derangement, especially in regards to intracellular energy homeostasis, which is brought on by glucose intolerance and insulin resistance in tissues. In this review, we highlight the lipids and carbohydrates that provoke hepatocyte injury and the mechanisms involved in lipotoxicity and glucotoxicity, including endoplasmic reticulum stress, oxidative stress and mitochondrial impairment. Through upregulation of proteins involved in various pathways including PKR-like ER kinase (PERK), CCAAT/enhancer-binding homologous protein (CHOP), c-Jun NH2-terminal kinase-1 (JNK), Bcl-2 interacting mediator (BIM), p53 upregulated modulator of apoptosis (PUMA), and eventually caspases, hepatocytes in lipotoxic states ultimately undergo apoptosis. The protective role of certain lipids and possible targets for pharmacological therapy are explored. Finally, we discuss the role of high fructose and glucose diets in contributing to organelle impairment and poor glucose transport mechanisms, which perpetuate hyperglycemia and hyperlipidemia by shunting of excess carbohydrates into lipogenesis.
Collapse
Affiliation(s)
- Manoela Mota
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
| | - Bubu A Banini
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Sophie C Cazanave
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Arun J Sanyal
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Nutrition, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
| |
Collapse
|
160
|
Bozaykut P, Sahin A, Karademir B, Ozer NK. Endoplasmic reticulum stress related molecular mechanisms in nonalcoholic steatohepatitis. Mech Ageing Dev 2016; 157:17-29. [DOI: 10.1016/j.mad.2016.07.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 06/23/2016] [Accepted: 07/02/2016] [Indexed: 12/18/2022]
|
161
|
Regnault C, Willison J, Veyrenc S, Airieau A, Méresse P, Fortier M, Fournier M, Brousseau P, Raveton M, Reynaud S. Metabolic and immune impairments induced by the endocrine disruptors benzo[a]pyrene and triclosan in Xenopus tropicalis. CHEMOSPHERE 2016; 155:519-527. [PMID: 27153234 DOI: 10.1016/j.chemosphere.2016.04.047] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/09/2016] [Accepted: 04/12/2016] [Indexed: 06/05/2023]
Abstract
Despite numerous studies suggesting that amphibians are highly sensitive to cumulative anthropogenic stresses, the role played by endocrine disruptors (EDs) in the decline of amphibian populations remains unclear. EDs have been extensively studied in adult amphibians for their capacity to disturb reproduction by interfering with the sexual hormone axis. Here, we studied the in vivo responses of Xenopus tropicalis males exposed to environmentally relevant concentrations of each ED, benzo[a]pyrene (BaP) and triclosan (TCS) alone (10 μg L(-1)) or a mixture of the two (10 μg L(-1) each) over a 24 h exposure period by following the modulation of the transcription of key genes involved in metabolic, sexual and immunity processes and the cellular changes in liver, spleen and testis. BaP, TCS and the mixture of the two all induced a marked metabolic disorder in the liver highlighted by insulin resistance-like and non-alcoholic fatty liver disease (NAFLD)-like phenotypes together with hepatotoxicity due to the impairment of lipid metabolism. For TCS and the mixture, these metabolic disorders were concomitant with modulation of innate immunity. These results confirmed that in addition to the reproductive effects induced by EDs in amphibians, metabolic disorders and immune system disruption should also be considered.
Collapse
Affiliation(s)
- Christophe Regnault
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; CNRS, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, BEeSy, F-38000, Grenoble, France.
| | - John Willison
- Univ. Grenoble-Alpes, Institut de recherches en technologies et Sciences pour le vivant, Laboratoire de chimie et biologie des métaux (iRTSV-LCBM), F-38000, France; CNRS, IRTSV-LCBM, F-38000, Grenoble, France; Commissariat à l'énergie atomique et aux énergies alternatives (CEA), iRTSV-LCBM, F-38000, Grenoble, France.
| | - Sylvie Veyrenc
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; CNRS, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, BEeSy, F-38000, Grenoble, France.
| | - Antinéa Airieau
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; CNRS, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, BEeSy, F-38000, Grenoble, France.
| | - Patrick Méresse
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, CUBE, F-38000, Grenoble, France.
| | | | | | | | - Muriel Raveton
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; CNRS, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, BEeSy, F-38000, Grenoble, France.
| | - Stéphane Reynaud
- Univ. Grenoble-Alpes, LECA, F-38000, Grenoble, France; CNRS, LECA, F-38000, Grenoble, France; Univ. Grenoble-Alpes, BEeSy, F-38000, Grenoble, France.
| |
Collapse
|
162
|
Lian J, Wei E, Groenendyk J, Das SK, Hermansson M, Li L, Watts R, Thiesen A, Oudit GY, Michalak M, Lehner R. Ces3/TGH Deficiency Attenuates Steatohepatitis. Sci Rep 2016; 6:25747. [PMID: 27181051 PMCID: PMC4867576 DOI: 10.1038/srep25747] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 04/22/2016] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease in developed countries. NAFLD describes a wide range of liver pathologies from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. NASH is distinguished from simple steatosis by inflammation, cell death and fibrosis. In this study we found that mice lacking triacylglycerol hydrolase (TGH, also known as carboxylesterase 3 or carboxylesterase 1d) are protected from high-fat diet (HFD) - induced hepatic steatosis via decreased lipogenesis, increased fatty acid oxidation and improved hepatic insulin sensitivity. To examine the effect of the loss of TGH function on the more severe NAFLD form NASH, we ablated Tgh expression in two independent NASH mouse models, Pemt(-/-) mice fed HFD and Ldlr(-/-) mice fed high-fat, high-cholesterol Western-type diet (WTD). TGH deficiency reduced liver inflammation, oxidative stress and fibrosis in Pemt(-/-) mice. TGH deficiency also decreased NASH in Ldlr(-/-) mice. Collectively, these findings indicate that TGH deficiency attenuated both simple hepatic steatosis and irreversible NASH.
Collapse
Affiliation(s)
- Jihong Lian
- Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Enhui Wei
- Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Jody Groenendyk
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Subhash K. Das
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Martin Hermansson
- Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta, Canada
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Lena Li
- Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Russell Watts
- Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Aducio Thiesen
- Department of Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Gavin Y. Oudit
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Marek Michalak
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Richard Lehner
- Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta, Canada
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
163
|
Rangboo V, Noroozi M, Zavoshy R, Rezadoost SA, Mohammadpoorasl A. The Effect of Artichoke Leaf Extract on Alanine Aminotransferase and Aspartate Aminotransferase in the Patients with Nonalcoholic Steatohepatitis. Int J Hepatol 2016; 2016:4030476. [PMID: 27293900 PMCID: PMC4879230 DOI: 10.1155/2016/4030476] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Revised: 02/22/2016] [Accepted: 03/10/2016] [Indexed: 02/07/2023] Open
Abstract
Background. Based on recent basic and clinical investigations, the extract of artichoke (Cynara scolymus) leaf has been revealed to be used for hepatoprotective and cholesterol reducing purposes. We aimed to assess the therapeutic effects of artichoke on biochemical and liver biomarkers in patients with nonalcoholic steatohepatitis (NASH). Methods. In a randomized double blind clinical trial, 60 consecutive patients suffering NASH were randomly assigned to receive Cynara scolymus extract (as 6 tablets per day consisting of 2700 mg extract of the herb) as the intervention group or placebo as the control group for two months. Results. Comparing changes in study markers following interventions showed improvement in liver enzymes. The levels of triglycerides and cholesterol were significantly reduced in the group treated with Cynara scolymus when compared to placebo group. To compare the role of Cynara scolymus use with placebo in changes in study parameters, multivariate linear regression models were employed indicating higher improvement in liver enzymes and also lipid profile particularly triglycerides and total cholesterol following administration of Cynara scolymus in comparison with placebo use. Conclusion. This study sheds light on the potential hepatoprotective activity and hypolipidemic effect of Cynara scolymus in management of NASH. This clinical trial is registered in the IRCT, Iranian Registry of Clinical Trials, by number IRCT2014070218321N1.
Collapse
Affiliation(s)
- Vajiheh Rangboo
- Department of Nutrition, Faculty of Health, Qazvin University of Medical Sciences, Qazvin, Iran
| | - Mostafa Noroozi
- Children Growth Research Center, Qazvin University of Medical Sciences, Qazvin, Iran
| | - Roza Zavoshy
- Department of Nutrition, Faculty of Nutrition, Qazvin University of Medical Sciences, Qazvin, Iran
| | | | | |
Collapse
|
164
|
Fengler VHI, Macheiner T, Kessler SM, Czepukojc B, Gemperlein K, Müller R, Kiemer AK, Magnes C, Haybaeck J, Lackner C, Sargsyan K. Susceptibility of Different Mouse Wild Type Strains to Develop Diet-Induced NAFLD/AFLD-Associated Liver Disease. PLoS One 2016; 11:e0155163. [PMID: 27167736 PMCID: PMC4863973 DOI: 10.1371/journal.pone.0155163] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 04/25/2016] [Indexed: 12/17/2022] Open
Abstract
Although non-alcoholic and alcoholic fatty liver disease have been intensively studied, concerning pathophysiological mechanisms are still incompletely understood. This may be due to the use of different animal models and resulting model-associated variation. Therefore, this study aimed to compare three frequently used wild type mouse strains in their susceptibility to develop diet-induced features of non-alcoholic/alcoholic fatty liver disease. Fatty liver disease associated clinical, biochemical, and histological features in C57BL/6, CD-1, and 129Sv WT mice were induced by (i) high-fat diet feeding, (ii) ethanol feeding only, and (iii) the combination of high-fat diet and ethanol feeding. Hepatic and subcutaneous adipose lipid profiles were compared in CD-1 and 129Sv mice. Additionally hepatic fatty acid composition was determined in 129Sv mice. In C57BL/6 mice dietary regimens resulted in heterogeneous hepatic responses, ranging from pronounced steatosis and inflammation to a lack of any features of fatty liver disease. Liver-related serum biochemistry showed high deviations within the regimen groups. CD-1 mice did not exhibit significant changes in metabolic and liver markers and developed no significant steatosis or inflammation as a response to dietary regimens. Although 129Sv mice showed no weight gain, this strain achieved most consistent features of fatty liver disease, apparent from concentration alterations of liver-related serum biochemistry as well as moderate steatosis and inflammation as a result of all dietary regimens. Furthermore, the hepatic lipid profile as well as the fatty acid composition of 129Sv mice were considerably altered, upon feeding the different dietary regimens. Accordingly, diet-induced non-alcoholic/alcoholic fatty liver disease is most consistently promoted in 129Sv mice compared to C57BL/6 and CD-1 mice. As a conclusion, this study demonstrates the importance of genetic background of used mouse strains for modeling diet-induced non-alcoholic/alcoholic fatty liver disease.
Collapse
MESH Headings
- Alanine Transaminase/metabolism
- Animals
- Aspartate Aminotransferases/metabolism
- Biomarkers/metabolism
- Cholesterol/metabolism
- Diet, High-Fat/adverse effects
- Dietary Fats/administration & dosage
- Disease Models, Animal
- Disease Susceptibility
- Ethanol/administration & dosage
- Fatty Acids, Nonesterified/metabolism
- Fatty Liver, Alcoholic/etiology
- Fatty Liver, Alcoholic/genetics
- Fatty Liver, Alcoholic/metabolism
- Fatty Liver, Alcoholic/pathology
- Liver/metabolism
- Liver/pathology
- Liver Function Tests
- Male
- Mice
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Inbred Strains
- Non-alcoholic Fatty Liver Disease/etiology
- Non-alcoholic Fatty Liver Disease/genetics
- Non-alcoholic Fatty Liver Disease/metabolism
- Non-alcoholic Fatty Liver Disease/pathology
- Species Specificity
- Subcutaneous Fat/metabolism
- Subcutaneous Fat/pathology
- Triglycerides/metabolism
- Weight Gain
Collapse
Affiliation(s)
| | - Tanja Macheiner
- BioPersMed/Biobank Graz, Medical University of Graz, Graz, Austria
| | - Sonja M. Kessler
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken, Germany
| | - Beate Czepukojc
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken, Germany
| | - Katja Gemperlein
- Department of Pharmacy, Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany
- Department of Microbial Natural Products, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research and Pharmaceutical Biotechnology (HZI), Saarbrücken, Germany
| | - Rolf Müller
- Department of Pharmacy, Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany
- Department of Microbial Natural Products, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research and Pharmaceutical Biotechnology (HZI), Saarbrücken, Germany
| | - Alexandra K. Kiemer
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken, Germany
| | - Christoph Magnes
- Institute for Biomedicine and Health Sciences, Joanneum Research, Graz, Austria
| | | | - Carolin Lackner
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Karine Sargsyan
- BioPersMed/Biobank Graz, Medical University of Graz, Graz, Austria
- * E-mail:
| |
Collapse
|
165
|
Kessler SM, Laggai S, Van Wonterg E, Gemperlein K, Müller R, Haybaeck J, Vandenbroucke RE, Ogris M, Libert C, Kiemer AK. Transient Hepatic Overexpression of Insulin-Like Growth Factor 2 Induces Free Cholesterol and Lipid Droplet Formation. Front Physiol 2016; 7:147. [PMID: 27199763 PMCID: PMC4843762 DOI: 10.3389/fphys.2016.00147] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 04/04/2016] [Indexed: 12/12/2022] Open
Abstract
Although insulin-like growth factor 2 (IGF2) has been reported to be overexpressed in steatosis and steatohepatitis, a causal role of IGF2 in steatosis development remains elusive. Aim of our study was to decipher the role of IGF2 in steatosis development. Hydrodynamic gene delivery of an Igf2 plasmid used for transient Igf2 overexpression employing codon-optimized plasmid DNA resulted in a strong induction of hepatic Igf2 expression. The exogenously delivered Igf2 had no influence on endogenous Igf2 expression. The downstream kinase AKT was activated in Igf2 animals. Decreased ALT levels mirrored the cytoprotective effect of IGF2. Serum cholesterol was increased and sulfo-phospho-vanillin colorimetric assay confirmed lipid accumulation in Igf2-livers while no signs of inflammation were observed. Interestingly, hepatic cholesterol and phospholipids, determined by thin layer chromatography, and free cholesterol by filipin staining, were specifically increased. Lipid droplet (LD) size was not changed, but their number was significantly elevated. Furthermore, free cholesterol, which can be stored in LDs and has been reported to be critical for steatosis progression, was elevated in Igf2 overexpressing mice. Accordingly, Hmgcr/HmgCoAR was upregulated. To have a closer look at de novo lipid synthesis we investigated expression of the lipogenic transcription factor SREBF1 and its target genes. SREBF1 was induced and also SREBF1 target genes were slightly upregulated. Interestingly, the expression of Cpt1a, which is responsible for mitochondrial fatty acid oxidation, was induced. Hepatic IGF2 expression induces a fatty liver, characterized by increased cholesterol and phospholipids leading to accumulation of LDs. We therefore suggest a causal role for IGF2 in hepatic lipid accumulation.
Collapse
Affiliation(s)
- Sonja M Kessler
- Department of Pharmacy, Pharmaceutical Biology, Saarland University Saarbrücken, Germany
| | - Stephan Laggai
- Department of Pharmacy, Pharmaceutical Biology, Saarland University Saarbrücken, Germany
| | - Elien Van Wonterg
- Inflammation Research Center, VIBGhent, Belgium; Department of Biomedical Molecular Biology, Ghent UniversityGhent, Belgium
| | - Katja Gemperlein
- Department of Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research and Pharmaceutical Biotechnology, Saarland University Saarbrücken, Germany
| | - Rolf Müller
- Department of Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research and Pharmaceutical Biotechnology, Saarland University Saarbrücken, Germany
| | | | - Roosmarijn E Vandenbroucke
- Inflammation Research Center, VIBGhent, Belgium; Department of Biomedical Molecular Biology, Ghent UniversityGhent, Belgium
| | - Manfred Ogris
- Department of Pharmaceutical Chemistry, University of Vienna Vienna, Austria
| | - Claude Libert
- Inflammation Research Center, VIBGhent, Belgium; Department of Biomedical Molecular Biology, Ghent UniversityGhent, Belgium
| | - Alexandra K Kiemer
- Department of Pharmacy, Pharmaceutical Biology, Saarland University Saarbrücken, Germany
| |
Collapse
|
166
|
Hepatocyte Growth Factor Reduces Free Cholesterol-Mediated Lipotoxicity in Primary Hepatocytes by Countering Oxidative Stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:7960386. [PMID: 27143995 PMCID: PMC4842075 DOI: 10.1155/2016/7960386] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 02/04/2016] [Indexed: 11/17/2022]
Abstract
Cholesterol overload in the liver has shown toxic effects by inducing the aggravation of nonalcoholic fatty liver disease to steatohepatitis and sensitizing to damage. Although the mechanism of damage is complex, it has been demonstrated that oxidative stress plays a prominent role in the process. In addition, we have proved that hepatocyte growth factor induces an antioxidant response in hepatic cells; in the present work we aimed to figure out the protective effect of this growth factor in hepatocytes overloaded with free cholesterol. Hepatocytes from mice fed with a high-cholesterol diet were treated or not with HGF, reactive oxygen species present in cholesterol overloaded hepatocytes significantly decreased, and this effect was particularly associated with the increase in glutathione and related enzymes, such as γ-gamma glutamyl cysteine synthetase, GSH peroxidase, and GSH-S-transferase. Our data clearly indicate that HGF displays an antioxidant response by inducing the glutathione-related protection system.
Collapse
|
167
|
Aylon Y, Gershoni A, Rotkopf R, Biton IE, Porat Z, Koh AP, Sun X, Lee Y, Fiel MI, Hoshida Y, Friedman SL, Johnson RL, Oren M. The LATS2 tumor suppressor inhibits SREBP and suppresses hepatic cholesterol accumulation. Genes Dev 2016; 30:786-97. [PMID: 27013235 PMCID: PMC4826395 DOI: 10.1101/gad.274167.115] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 03/01/2016] [Indexed: 02/07/2023]
Abstract
In this study, Aylon et al. performed a screen for proteins that interact with LATS2, a key player in the Hippo pathway. They delineate a new role for LATS2 in the regulation of cholesterol metabolism through direct interaction with and inhibition of the transcription factor SREBP2, a master regulator of cholesterol homeostasis. The Hippo signaling pathway is a major regulator of organ size. In the liver, Hippo pathway deregulation promotes hyperplasia and hepatocellular carcinoma primarily through hyperactivation of its downstream effector, YAP. The LATS2 tumor suppressor is a core member of the Hippo pathway. A screen for LATS2-interacting proteins in liver-derived cells identified the transcription factor SREBP2, master regulator of cholesterol homeostasis. LATS2 down-regulation caused SREBP activation and accumulation of excessive cholesterol. Likewise, mice harboring liver-specific Lats2 conditional knockout (Lats2-CKO) displayed constitutive SREBP activation and overexpressed SREBP target genes and developed spontaneous fatty liver disease. Interestingly, the impact of LATS2 depletion on SREBP-mediated transcription was clearly distinct from that of YAP overexpression. When challenged with excess dietary cholesterol, Lats2-CKO mice manifested more severe liver damage than wild-type mice. Surprisingly, apoptosis, inflammation, and fibrosis were actually attenuated relative to wild-type mice, in association with impaired p53 activation. Subsequently, Lats2-CKO mice failed to recover effectively from cholesterol-induced damage upon return to a normal diet. Additionally, decreased LATS2 mRNA in association with increased SREBP target gene expression was observed in a subset of human nonalcoholic fatty liver disease cases. Together, these findings further highlight the tight links between tumor suppressors and metabolic homeostasis.
Collapse
Affiliation(s)
- Yael Aylon
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Anat Gershoni
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ron Rotkopf
- Bioinformatics Unit, Faculty of Biological Services, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Inbal E Biton
- Department of Veterinary Resources, Faculty of Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ziv Porat
- Flow Cytometry Unit, Biological Services Department, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Anna P Koh
- Division of Liver Diseases, Department of Medicine, Liver Cancer Program, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Xiaochen Sun
- Division of Liver Diseases, Department of Medicine, Liver Cancer Program, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Youngmin Lee
- Division of Liver Diseases, Department of Medicine, Liver Cancer Program, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Maria-Isabel Fiel
- Division of Liver Diseases, Department of Medicine, Liver Cancer Program, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Yujin Hoshida
- Division of Liver Diseases, Department of Medicine, Liver Cancer Program, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Scott L Friedman
- Division of Liver Diseases, Department of Medicine, Liver Cancer Program, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Randy L Johnson
- Department of Biochemistry and Molecular Biology, Division of Basic Science Research, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Moshe Oren
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| |
Collapse
|
168
|
Li XL, Sui JQ, Lu LL, Zhang NN, Xu X, Dong QY, Xin YN, Xuan SY. Gene polymorphisms associated with non-alcoholic fatty liver disease and coronary artery disease: a concise review. Lipids Health Dis 2016; 15:53. [PMID: 26965314 PMCID: PMC4785616 DOI: 10.1186/s12944-016-0221-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 03/04/2016] [Indexed: 12/14/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease which represents a wide spectrum of hepatic damage. Several studies have reported that NAFLD is a strong independent risk factor for coronary artery disease (CAD). And patients with NAFLD are at higher risk and suggested undergoperiodic cardiovascular risk assessment. Cardiovascular disease (CVD) is responsible for the main cause of death in patients with NAFLD, and is mostly influenced by genetic factors. Both NAFLD and CAD are heterogeneous disease. Common pathways involved in the pathogenesis of NAFLD and CAD includes insulin resistance (IR), atherogenic dyslipidemia, subclinical inflammation, oxidative stress, etc. Genomic characteristics of these two diseases have been widely studied, further research about the association of these two diseases draws attention. The gene polymorphisms of adiponectin-encoding gene (ADIPOQ), leptin receptor (LEPR), apolipoprotein C3 (APOC3), peroxisome proliferator-activated receptors (PPAR), sterol regulatory elementbinding proteins (SREBP), transmembrane 6 superfamily member 2 (TM6SF2), microsomal triglyceride transfer protein (MTTP), tumor necrosis factors-alpha (TNF-α) and manganese superoxide dismutase (MnSOD) have been reported to be related to NAFLD and CAD. In this review, we aimed to provide an overview of recent insights into the genetic basis of NAFLD and CAD.
Collapse
Affiliation(s)
- Xiao-Lin Li
- Department of Gastroenterology, Qingdao Municipal Hospital, Dalian Medical University, Qingdao, 266011, China
| | - Jian-Qing Sui
- Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao, 266011, China
| | - Lin-Lin Lu
- Digestive Disease Key Laboratory of Qingdao, Qingdao, 266071, China.,Central Laboratories, Qingdao Municipal Hospital, Qingdao, 266071, China
| | - Nan-Nan Zhang
- Department of Gastroenterology, Qingdao Municipal Hospital, Dalian Medical University, Qingdao, 266011, China
| | - Xin Xu
- Department of Gastroenterology, Qingdao Municipal Hospital, Dalian Medical University, Qingdao, 266011, China
| | - Quan-Yong Dong
- Department of Gastroenterology, Qingdao Municipal Hospital, Dalian Medical University, Qingdao, 266011, China
| | - Yong-Ning Xin
- Department of Gastroenterology, Qingdao Municipal Hospital, Dalian Medical University, Qingdao, 266011, China. .,Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao, 266011, China. .,Digestive Disease Key Laboratory of Qingdao, Qingdao, 266071, China.
| | - Shi-Ying Xuan
- Department of Gastroenterology, Qingdao Municipal Hospital, Dalian Medical University, Qingdao, 266011, China. .,Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao, 266011, China. .,Digestive Disease Key Laboratory of Qingdao, Qingdao, 266071, China.
| |
Collapse
|
169
|
Højland Ipsen D, Tveden-Nyborg P, Lykkesfeldt J. Normal weight dyslipidemia: Is it all about the liver? Obesity (Silver Spring) 2016; 24:556-67. [PMID: 26868960 DOI: 10.1002/oby.21443] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/02/2015] [Accepted: 11/30/2015] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The liver coordinates lipid metabolism and may play a vital role in the development of dyslipidemia, even in the absence of obesity. Normal weight dyslipidemia (NWD) and patients with nonalcoholic fatty liver disease (NAFLD) who do not have obesity constitute a unique subset of individuals characterized by dyslipidemia and metabolic deterioration. This review examined the available literature on the role of the liver in dyslipidemia and the metabolic characteristics of patients with NAFLD who do not have obesity. METHODS PubMed was searched using the following keywords: nonobese, dyslipidemia, NAFLD, NWD, liver, and metabolically obese/unhealthy normal weight. Additionally, article bibliographies were screened, and relevant citations were retrieved. Studies were excluded if they had not measured relevant biomarkers of dyslipidemia. RESULTS NWD and NAFLD without obesity share a similar abnormal metabolic profile. When compared with patients with NAFLD who have obesity, the metabolic abnormalities of NAFLD without obesity are similar or less severe. Furthermore, hepatic lesions develop independent of obesity, and the extent of dyslipidemia seems comparable. CONCLUSIONS NAFLD may impair hepatic lipid handling, causing faulty lipid homeostasis, and serves as a likely starting point for initiation and propagation of dyslipidemia along with associated comorbidities in patients without obesity.
Collapse
Affiliation(s)
- David Højland Ipsen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pernille Tveden-Nyborg
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Lykkesfeldt
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
170
|
Ioannou GN. The Role of Cholesterol in the Pathogenesis of NASH. Trends Endocrinol Metab 2016; 27:84-95. [PMID: 26703097 DOI: 10.1016/j.tem.2015.11.008] [Citation(s) in RCA: 325] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 11/12/2015] [Accepted: 11/16/2015] [Indexed: 01/01/2023]
Abstract
Lipotoxicity drives the development of progressive hepatic inflammation and fibrosis in a subgroup of patients with nonalcoholic fatty liver disease (NAFLD), causing nonalcoholic steatohepatitis (NASH) and even progression to cirrhosis and hepatocellular carcinoma (HCC). While the underlying molecular mechanisms responsible for the development of inflammation and fibrosis that characterize progressive NASH remain unclear, emerging evidence now suggests that hepatic free cholesterol (FC) is a major lipotoxic molecule critical in the development of experimental and human NASH. In this review, we examine the effects of excess FC in hepatocytes, Kupffer cells (KCs), and hepatic stellate cells (HSCs), and the subcellular mechanisms by which excess FC can induce cellular toxicity or proinflammatory and profibrotic effects in these cells.
Collapse
Affiliation(s)
- George N Ioannou
- Research and Development, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA; Division of Gastroenterology, Department of Medicine, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA; University of Washington, Seattle, WA, USA.
| |
Collapse
|
171
|
Hu HJ, Luo XG, Dong QQ, Mu A, Shi GL, Wang QT, Chen XY, Zhou H, Zhang TC, Pan LW. Ethanol extract of Zhongtian hawthorn lowers serum cholesterol in mice by inhibiting transcription of 3-hydroxy-3-methylglutaryl-CoA reductase via nuclear factor-kappa B signal pathway. Exp Biol Med (Maywood) 2016; 241:667-74. [PMID: 26825354 DOI: 10.1177/1535370215627032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 12/15/2015] [Indexed: 12/26/2022] Open
Abstract
Hawthorn is a berry-like fruit from the species of Crataegus. In China, it has another more famous name, Shan-Zha, which has been used to improve digestion as a traditional Chinese medicine or food for thousands of years. Moreover, during the last decades, hawthorn has received more attention because of its potential to treat cardiovascular diseases. However, currently, only fruits of C. pinnatifida and C. pinnatifida var. major are included as Shan-Zha in the Chinese Pharmacopoeia. In this study, our results showed that the ethanol extract of Zhongtian hawthorn, a novel grafted cultivar of C. cuneata (wild Shan-Zha), could markedly reduce body weight and levels of serum total cholesterol, triglyceride, low-density lipoprotein cholesterol, and liver cholesterol of hyperlipidemia mice. It could suppress the stimulation effect of high-fat diet on the transcription of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and p65, and counteract the downregulation of CYP7A1 and LDLR. In addition, the results of luciferase reporter assay and Western blot showed that the transcriptional activity of HMGCR promoter was inhibited by Zhongtian hawthorn ethanol extract in a dose-dependent manner, while overexpression of p65 could reverse this transcriptional repression effect. These results suggested that Zhongtian hawthorn could provide health benefits by counteracting the high-fat diet-induced hypercholesteolemic and hyperlipidemic effects in vivo, and the mechanism underlying this event was mainly dependent on the suppressive effect of Zhongtian hawthorn ethanol extract on the transcription of HMGCR via nuclear factor-kappa B (NF-κB) signal pathway. Therefore, this novel cultivar of hawthorn cultivar which has much bigger fruits, early bearing, high yield, cold resistance, and drought resistance, might be considered as a good alternative to Shan-Zha and has great value in the food and medicine industry. In addition, to our best knowledge, this is also the first report that the extract of Crataegus could suppress the transcription of HMGCR via NF-κB signal pathway.
Collapse
Affiliation(s)
- Hai-Jie Hu
- Key Lab of Industrial Fermentation Microbiology (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457, P. R. China Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Xue-Gang Luo
- Key Lab of Industrial Fermentation Microbiology (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457, P. R. China Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Qing-Qing Dong
- Key Lab of Industrial Fermentation Microbiology (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457, P. R. China Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Ai Mu
- Key Lab of Industrial Fermentation Microbiology (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457, P. R. China Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Guo-Long Shi
- Key Lab of Industrial Fermentation Microbiology (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457, P. R. China Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Qiu-Tong Wang
- Key Lab of Industrial Fermentation Microbiology (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457, P. R. China Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Xiao-Ying Chen
- Key Lab of Industrial Fermentation Microbiology (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457, P. R. China Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Hao Zhou
- Key Lab of Industrial Fermentation Microbiology (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457, P. R. China Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Tong-Cun Zhang
- Key Lab of Industrial Fermentation Microbiology (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457, P. R. China Tianjin Key Lab of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, P. R. China
| | - Li-Wen Pan
- Hezhou University, Hezhou 542800, P. R. China
| |
Collapse
|
172
|
Wu R, Nakatsu G, Zhang X, Yu J. Pathophysiological mechanisms and therapeutic potentials of macrophages in non-alcoholic steatohepatitis. Expert Opin Ther Targets 2016; 20:615-26. [PMID: 26609894 DOI: 10.1517/14728222.2016.1125883] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Non-alcoholic steatohepatitis (NASH), a hepatic manifestation of metabolic syndrome, is a major cause of morbidity and healthcare burden worldwide. While the molecular pathogenesis of NASH remains unclear and therapeutic options are limited, inflammation is recognized as an essential factor for NASH development. Factors that link NASH to inflammation are macrophages and their secreted cytokines. AREAS COVERED This review summarizes the current knowledge of macrophage-mediated molecular pathways in NASH to shed insights on potential pharmacotherapeutic applications. EXPERT OPINION Macrophages are not only known for their role of phagocytosis in innate immunity, but also for both extrinsic and intrinsic regulation of inflammatory functions of many cytokines. Recent advances have revealed the effects of macrophage recruitment and polarization on the development of NASH. We and others have shown that the proliferation of hepatic macrophages and the subsequent production of pro-inflammatory cytokines initiates inflammatory cascades, orchestrates activities of transcription factors involved in lipid metabolism/translocation, and modulates programmed cell death. Together, these findings support the pathophysiological role of macrophages in the pathogenesis of NASH. Thus, evaluating potential therapeutic targets against the infiltration and/or polarization of specific macrophage subtypes is of clinical interest for alleviation of early-stage NASH, with the goal of halting disease progression.
Collapse
Affiliation(s)
- Ruonan Wu
- a Institute of Digestive Disease and the Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences , CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong , Shatin , Hong Kong
| | - Geicho Nakatsu
- a Institute of Digestive Disease and the Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences , CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong , Shatin , Hong Kong
| | - Xiang Zhang
- a Institute of Digestive Disease and the Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences , CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong , Shatin , Hong Kong
| | - Jun Yu
- a Institute of Digestive Disease and the Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences , CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong , Shatin , Hong Kong
| |
Collapse
|
173
|
Ham JR, Lee HI, Choi RY, Sim MO, Seo KI, Lee MK. Anti-steatotic and anti-inflammatory roles of syringic acid in high-fat diet-induced obese mice. Food Funct 2016; 7:689-697. [DOI: 10.1039/c5fo01329a] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2023]
Abstract
This study examined the effects of syringic acid (SA) on obese diet-induced hepatic dysfunction.
Collapse
Affiliation(s)
- Ju Ri Ham
- Department of Food and Nutrition
- Sunchon National University
- Suncheon
- Korea
| | - Hae-In Lee
- Mokpo Marin Food-Industry Research Center
- Mokpo
- Korea
| | - Ra-Yeong Choi
- Department of Food and Nutrition
- Sunchon National University
- Suncheon
- Korea
| | - Mi-Ok Sim
- Jeollanamdo Development Institute of Korean Traditional Medicine
- Jangheung
- Korea
| | - Kwon-Il Seo
- Department of Biotechnology
- Dong-A University
- Busan
- Korea
| | - Mi-Kyung Lee
- Department of Food and Nutrition
- Sunchon National University
- Suncheon
- Korea
- Suncheon Research Center for Natural Medicines
| |
Collapse
|
174
|
Achiwa K, Ishigami M, Ishizu Y, Kuzuya T, Honda T, Hayashi K, Hirooka Y, Katano Y, Goto H. DSS colitis promotes tumorigenesis and fibrogenesis in a choline-deficient high-fat diet-induced NASH mouse model. Biochem Biophys Res Commun 2016; 470:15-21. [DOI: 10.1016/j.bbrc.2015.12.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 12/02/2015] [Indexed: 02/08/2023]
|
175
|
Exercise-Induced Changes in Caveolin-1, Depletion of Mitochondrial Cholesterol, and the Inhibition of Mitochondrial Swelling in Rat Skeletal Muscle but Not in the Liver. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2016:3620929. [PMID: 26839631 PMCID: PMC4709766 DOI: 10.1155/2016/3620929] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/22/2015] [Accepted: 10/11/2015] [Indexed: 01/09/2023]
Abstract
The reduction in cholesterol in mitochondria, observed after exercise, is related to the inhibition of mitochondrial swelling. Caveolin-1 (Cav-1) plays an essential role in the regulation of cellular cholesterol metabolism and is required by various signalling pathways. Therefore, the aim of this study was to investigate the effect of prolonged swimming on the mitochondrial Cav-1 concentration; additionally, we identified the results of these changes as they relate to the induction of changes in the mitochondrial swelling and cholesterol in rat skeletal muscle and liver. Male Wistar rats were divided into a sedentary control group and an exercise group. The exercised rats swam for 3 hours and were burdened with an additional 3% of their body weight. After the cessation of exercise, their quadriceps femoris muscles and livers were immediately removed for experimentation. The exercise protocol caused an increase in the Cav-1 concentration in crude muscle mitochondria; this was related to a reduction in the cholesterol level and an inhibition of mitochondrial swelling. There were no changes in rat livers, with the exception of increased markers of oxidative stress in mitochondria. These data indicate the possible role of Cav-1 in the adaptive change in the rat muscle mitochondria following exercise.
Collapse
|
176
|
Recent insights on the role of cholesterol in non-alcoholic fatty liver disease. Biochim Biophys Acta Mol Basis Dis 2015; 1852:1765-78. [DOI: 10.1016/j.bbadis.2015.05.015] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/25/2015] [Accepted: 05/27/2015] [Indexed: 12/18/2022]
|
177
|
Seven weeks of Western diet in apolipoprotein-E-deficient mice induce metabolic syndrome and non-alcoholic steatohepatitis with liver fibrosis. Sci Rep 2015; 5:12931. [PMID: 26263022 PMCID: PMC4531783 DOI: 10.1038/srep12931] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 07/14/2015] [Indexed: 12/18/2022] Open
Abstract
Non-alcoholic steatohepatitis (NASH) is characterised by hepatic steatosis, inflammation and fibrosis, which might progress to cirrhosis. Human NASH is associated with metabolic syndrome (MS). Currently, rodent NASH models either lack significant fibrosis or MS. ApoE−/− mice are a MS model used in cardiovascular research. The aim of this work was to establish and characterise a novel mouse NASH model with significant fibrosis and MS. ApoE−/− and wild-type mice (wt) were fed either a western-diet (WD), methionine-choline-deficient-diet (MCD) or normal chow. Liver histology, RT-PCR, hepatic hydroxyproline content, triglycerides and cholesterol levels, and fasting glucose levels assessed hepatic steatosis, inflammation and fibrosis. Further, portal pressure was measured invasively, and kidney pathology was assessed by histology. ApoE−/− mice receiving WD showed abnormal glucose tolerance, hepatomegaly, weight gain and full spectrum of NASH including hepatic steatosis, fibrosis and inflammation, with no sign of renal damage. MCD-animals showed less severe liver fibrosis, but detectable renal pathological changes, besides weight loss and unchanged glucose tolerance. This study describes a murine NASH model with distinct hepatic steatosis, inflammation and fibrosis, without renal pathology. ApoE−/− mice receiving WD represent a novel and fast model with all characteristic features of NASH and MS well suitable for NASH research.
Collapse
|
178
|
Hu Y, Dong C, Chen M, Chen Y, Gu A, Xia Y, Sun H, Li Z, Wang Y. Effects of monobutyl phthalate on steroidogenesis through steroidogenic acute regulatory protein regulated by transcription factors in mouse Leydig tumor cells. J Endocrinol Invest 2015; 38:875-84. [PMID: 25903692 DOI: 10.1007/s40618-015-0279-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 03/17/2015] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Dibutyl phthalate (DBP) is one of the most widely used phthalate esters, and it is ubiquitous in the environment. DBP and its major metabolite, monobutyl phthalate (MBP), change steroid biosynthesis and impair male reproductive function. However, the regulatory mechanism underlying the steroid biosynthesis disruption by MBP is still unclear. METHODS We analyzed the progesterone production, steroidogenic acute regulatory protein (StAR) mRNA, protein expression, and DNA-binding affinity of transcription factors (SF-1 and GATA-4). RESULTS Our results reveal that MBP inhibited progesterone production. At the same time, StAR mRNA and protein were decreased after MBP exposure. Furthermore, electrophoretic mobility shift assay showed that DNA-binding affinity of transcription factors (SF-1 and GATA-4) was decreased in a dose-dependent manner after MBP treatments. Western blot tests next confirmed that protein of SF-1 was decreased, but GATA-4 protein was unchanged. However, phosphorylated GATA-4 protein was decreased with 800 μM of MBP. CONCLUSIONS This study reveals an important and novel mechanism whereby SF-1 and GATA-4 may regulate StAR during MBP-induced steroidogenesis disruption.
Collapse
Affiliation(s)
- Y Hu
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing, 211166, China
| | | | | | | | | | | | | | | | | |
Collapse
|
179
|
Abstract
Cardiovascular disease is a major cause of morbidity and mortality in patients with type 2 diabetes mellitus, with a two- to fourfold increase in cardiovascular disease risk compared with non-diabetic individuals. Abnormalities in lipid metabolism that are observed in the context of type 2 diabetes are among the major factors contributing to an increased cardiovascular risk. Diabetic dyslipidaemia includes not only quantitative lipoprotein abnormalities, but also qualitative and kinetic abnormalities that, together, result in a shift towards a more atherogenic lipid profile. The primary quantitative lipoprotein abnormalities are increased triacylglycerol (triglyceride) levels and decreased HDL-cholesterol levels. Qualitative lipoprotein abnormalities include an increase in large, very low-density lipoprotein subfraction 1 (VLDL1) and small, dense LDLs, as well as increased triacylglycerol content of LDL and HDL, glycation of apolipoproteins and increased susceptibility of LDL to oxidation. The main kinetic abnormalities are increased VLDL1 production, decreased VLDL catabolism and increased HDL catabolism. In addition, even though LDL-cholesterol levels are typically normal in patients with type 2 diabetes, LDL particles show reduced turnover, which is potentially atherogenic. Although the pathophysiology of diabetic dyslipidaemia is not fully understood, the insulin resistance and relative insulin deficiency observed in patients with type 2 diabetes are likely to contribute to these lipid changes, as insulin plays an important role in regulating lipid metabolism. In addition, some adipocytokines, such as adiponectin or retinol-binding protein 4, may also contribute to the development of dyslipidaemia in patients with type 2 diabetes.
Collapse
Affiliation(s)
- Bruno Vergès
- Service Endocrinologie, Diabétologie et Maladies Métaboliques, Hôpital du Bocage, 2 bd Maréchal de Lattre de Tassigny, 21000, Dijon, France,
| |
Collapse
|
180
|
Mirtoselect, an anthocyanin-rich bilberry extract, attenuates non-alcoholic steatohepatitis and associated fibrosis in ApoE(∗)3Leiden mice. J Hepatol 2015; 62:1180-6. [PMID: 25514555 DOI: 10.1016/j.jhep.2014.12.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/28/2014] [Accepted: 12/03/2014] [Indexed: 12/18/2022]
Abstract
BACKGROUND & AIMS Anthocyanins may have beneficial effects on lipid metabolism and inflammation and are demonstrated to have hepatoprotective properties in models of restraint-stress- and chemically-induced liver damage. However, their potential to protect against non-alcoholic steatohepatitis (NASH) under conditions relevant for human pathogenesis remains unclear. Therefore, we studied the effects of the standardised anthocyanin-rich extract Mirtoselect on diet-induced NASH in a translational model of disease. METHODS ApoE(∗)3Leiden mice were fed a Western-type cholesterol-containing diet without (HC) or with 0.1% (w/w) Mirtoselect (HCM) for 20weeks to study the effects on diet-induced NASH. RESULTS Mirtoselect attenuated HC-induced hepatic steatosis, as observed by decreased macro- and microvesicular hepatocellular lipid accumulation and reduced hepatic cholesteryl ester content. This anti-steatotic effect was accompanied by local anti-inflammatory effects in liver, as demonstrated by reduced inflammatory cell clusters and reduced neutrophil infiltration in HCM. On a molecular level, HC diet significantly induced hepatic expression of pro-inflammatory genes Tnf, Emr1, Ccl2, Mpo, Cxcl1, and Cxcl2 while this induction was less pronounced or significantly decreased in HCM. A similar quenching effect was observed for HC-induced pro-fibrotic genes, Acta2 and Col1a1 and this anti-fibrotic effect of Mirtoselect was confirmed histologically. Many of the pro-inflammatory and pro-fibrotic parameters positively correlated with intrahepatic free cholesterol levels. Mirtoselect significantly reduced accumulation and crystallisation of intrahepatic free cholesterol, providing a possible mechanism for the observed hepatoprotective effects. CONCLUSIONS Mirtoselect attenuates development of NASH, reducing hepatic lipid accumulation, inflammation and fibrosis, possibly mediated by local anti-inflammatory effects associated with reduced accumulation and crystallisation of intrahepatic free cholesterol.
Collapse
|
181
|
P2X7 receptor as a key player in oxidative stress-driven cell fate in nonalcoholic steatohepatitis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:172493. [PMID: 25815106 PMCID: PMC4359843 DOI: 10.1155/2015/172493] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 02/17/2015] [Indexed: 02/06/2023]
Abstract
Incidences of nonalcoholic fatty liver disease parallels increase in the global obesity epidemic. NAFLD has been shown to be associated with risks of cardiometabolic disorders and kidney disturbances. It is accompanied by insulin and leptin resistance that complicate the diagnosis and treatment of this public health menace. Though significant research is underway for understanding the molecular mechanisms of NAFLD and its subsequent inflammatory and fibrotic manifestations like nonalcoholic steatohepatitis, the role of purinergic receptors has been unclear. It is increasingly being recognized that damage associated molecular patterns like NAD and ATP that are released from injured cells via hepatocellular injury either by oxidative stress or lipotoxicity from steatosis activate the purinergic receptor. Based on evidence from inflammatory responses in the airways and vasculature and autoimmune complications in humans and rodents, it is beyond doubt that hepatocellular inflammation such as that seen in NASH can result from the activation of purinergic receptors. This event can result in the formation of inflammasomes and can be an important pathway for the progression of NASH. The present review evaluates the current knowledge of the role of oxidative stress and its signaling via P2X7 receptors in hepatocellular injury that might contribute to the NASH pathophysiology.
Collapse
|
182
|
Ramadori P, Kroy D, Streetz KL. Immunoregulation by lipids during the development of non-alcoholic steatohepatitis. Hepatobiliary Surg Nutr 2015; 4:11-23. [PMID: 25713801 DOI: 10.3978/j.issn.2304-3881.2015.01.02] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 12/19/2014] [Indexed: 12/24/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) represents the most common liver disorder in western countries and it is commonly associated with obesity and progression of the metabolic syndrome. Comprehending a wide spectrum of pathologic features, it is currently well recognized that a key point for the integrity of hepatocyte functionality in NAFLD is the progression from simple steatosis to non-alcoholic steatohepatitis (NASH). Indeed, activation of the innate immune system in response to hepatic metabolic stresses represents a central process that determines the evolution and the reversibility of liver damage. Despite of the burden of studies published in recent years, it is still intriguingly unclear how accumulation of lipids in hepatocytes triggers the activation of the inflammatory response leading to the recruitment of infiltrating cells of extra-hepatic origins. In this review we offer a general view on recent advances pointing out how different classes of lipids are able to specifically affect hepatocytes functionality and survival, thus differently influencing the organization of the hepatic immune response. On the other hand, we gathered recent studies intending to illustrate the basic mechanisms through which several non-parenchymal hepatic and extra-hepatic cell populations get activated in response to lipids. Finally, we indicate latter findings proposing how the immune system majorly contributes to the progression of NASH.
Collapse
Affiliation(s)
- Pierluigi Ramadori
- Department of Internal Medicine III, RWTH University Hospital, Aachen 52074, Germany
| | - Daniela Kroy
- Department of Internal Medicine III, RWTH University Hospital, Aachen 52074, Germany
| | - Konrad L Streetz
- Department of Internal Medicine III, RWTH University Hospital, Aachen 52074, Germany
| |
Collapse
|
183
|
SUN CHUANZHENG, HUANG FEIZHOU, LIU XUNYANG, XIAO XUEFEI, YANG MINGSHI, HU GUI, LIU HUAIZHENG, LIAO LIANGKAN. miR-21 regulates triglyceride and cholesterol metabolism in non-alcoholic fatty liver disease by targeting HMGCR. Int J Mol Med 2015; 35:847-53. [DOI: 10.3892/ijmm.2015.2076] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 01/16/2015] [Indexed: 02/07/2023] Open
|
184
|
A genetic risk score is associated with hepatic triglyceride content and non-alcoholic steatohepatitis in Mexicans with morbid obesity. Exp Mol Pathol 2015; 98:178-83. [PMID: 25597287 DOI: 10.1016/j.yexmp.2015.01.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 01/13/2015] [Accepted: 01/14/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND AIMS Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) near/in PNPLA3, NCAN, LYPLAL1, PPP1R3B, and GCKR genes associated with non-alcoholic fatty liver disease (NAFLD) mainly in individuals of European ancestry. The aim of the study was to test whether these genetic variants and a genetic risk score (GRS) are associated with elevated liver fat content and non-alcoholic steatohepatitis (NASH) in Mexicans with morbid obesity. METHODS 130 morbidly obese Mexican individuals were genotyped for six SNPs in/near PNPLA3, NCAN, LYPLAL1, PPP1R3B, and GCKR genes. Hepatic fat content [triglyceride (HTG) and total cholesterol (HTC)] was quantified directly in liver biopsies and NASH was diagnosed by histology. A GRS was tested for association with liver fat content and NASH using logistic regression models. In addition, 95 ancestry-informative markers were genotyped to estimate population admixture proportions. RESULTS After adjusting for age, sex and admixture, PNPLA3, LYPLAL1, GCKR and PPP1R3B polymorphisms were associated with higher HTG content (P < 0.05 for PNPLA3, LYPLAL1, GCKR polymorphisms and P = 0.086 for PPP1R3B). The GRS was significantly associated with higher HTG and HTC content (P = 1.0 × 10(-4) and 0.048, respectively), steatosis stage (P = 0.029), and higher ALT levels (P = 0.002). Subjects with GRS ≥ 6 showed a significantly increased risk of NASH (OR = 2.55, P = 0.045) compared to those with GRS ≤ 5. However, the GRS did not predict NASH status, as AUC of ROC curves was 0.56 (P = 0.219). CONCLUSION NAFLD associated loci in Europeans and a GRS based on these loci contribute to the accumulation of hepatic lipids and NASH in morbidly obese Mexican individuals.
Collapse
|
185
|
Acid sphingomyelinase-ceramide system in steatohepatitis: a novel target regulating multiple pathways. J Hepatol 2015; 62:219-33. [PMID: 25281863 DOI: 10.1016/j.jhep.2014.09.023] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 09/13/2014] [Accepted: 09/24/2014] [Indexed: 02/07/2023]
Abstract
Steatohepatitis (SH) is an intermediate stage of fatty liver disease and is one of the most common causes of chronic liver disease worldwide that may progress to cirrhosis and liver cancer. SH encompasses alcoholic and non-alcoholic steatohepatitis, the latter being of particular concern as it is associated with obesity and insulin resistance and has become a major cause of liver transplantation. The molecular mechanisms governing the transition from steatosis to SH are not fully understood. Here we discuss emerging data indicating that the acid sphingomyelinase (ASMase), a specific mechanism of ceramide generation, is required for the activation of key pathways that regulate steatosis, fibrosis and lipotoxicity, including endoplasmic reticulum stress, autophagy and lysosomal membrane permeabilization. Moreover, ASMase modulates alterations of the methionine cycle and phosphatidylcholine homeostasis, two crucial events involved in SH that regulate methylation reactions, antioxidant defence and membrane integrity. These new findings suggest that targeting ASMase in combination with restoring methionine metabolism and phosphatidylcholine levels may be of utility in the treatment of SH.
Collapse
|
186
|
Ringelhan M, Reisinger F, Yuan D, Weber A, Heikenwalder M. Modeling human liver cancer heterogeneity: virally induced transgenic models and mouse genetic models of chronic liver inflammation. CURRENT PROTOCOLS IN PHARMACOLOGY 2014; 67:14.31.1-14.31.17. [PMID: 25446288 DOI: 10.1002/0471141755.ph1431s67] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In addition to being the most common primary liver cancer, hepatocellular carcinoma (HCC) is the second most common cause of cancer-related death in humans. Treatment options are limited for this chemoresistant cancer, with liver transplantation and surgical intervention in early stages being the most successful treatments. Drug development over the past 15 years has focused on generating mouse models that mimic the human pathology for HCC. This has enabled the laboratory testing of potentially new human therapeutics. Described in this unit are the classification of HCC and an overview of hepatitis virus-related transgenic and genetically engineered mouse models (GEMMs) that are employed for elucidating the mechanism(s) responsible for the development of HCC, with particular emphasis on genetic, dietary, and environmental factors.
Collapse
Affiliation(s)
- Marc Ringelhan
- Institute of Virology, München, Germany.,2nd Medical Department, Klinikum rechts der Isar, Technische Universität München, München, Germany.,German Center for Infection Research (DZIF), München, Germany
| | | | | | - Achim Weber
- Institute of Surgical Pathology, Zürich, Switzerland
| | | |
Collapse
|
187
|
Gan LT, Van Rooyen DM, Koina ME, McCuskey RS, Teoh NC, Farrell GC. Hepatocyte free cholesterol lipotoxicity results from JNK1-mediated mitochondrial injury and is HMGB1 and TLR4-dependent. J Hepatol 2014; 61:1376-84. [PMID: 25064435 DOI: 10.1016/j.jhep.2014.07.024] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/02/2014] [Accepted: 07/15/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Free cholesterol (FC) accumulates in non-alcoholic steatohepatitis (NASH) but not in simple steatosis. We sought to establish how FC causes hepatocyte injury. METHODS In NASH-affected livers from diabetic mice, subcellular FC distribution (filipin fluorescence) was established by subcellular marker co-localization. We loaded murine hepatocytes with FC by incubation with low-density lipoprotein (LDL) and studied the effects of FC on JNK1 activation, mitochondrial injury and cell death and on the amplifying roles of the high-mobility-group-box 1 (HMGB1) protein and the Toll-like receptor 4 (TLR4). RESULTS In NASH, FC localized to hepatocyte plasma membrane, mitochondria and ER. This was reproduced in FC-loaded hepatocytes. At 40 μM LDL, hepatocyte FC increased to cause LDH leakage, apoptosis and necrosis associated with JNK1 activation (c-Jun phosphorylation), mitochondrial membrane pore transition, cytochrome c release, oxidative stress (GSSG:GSH ratio) and ATP depletion. Mitochondrial swelling and crystae disarray were evident by electron microscopy. Jnk1(-/-) and Tlr4(-/-) hepatocytes were refractory to FC lipotoxicity; JNK inhibitors (1-2 μM CC-401, CC-930) blocked apoptosis and necrosis. Cyclosporine A and caspase-3 inhibitors protected FC-loaded hepatocytes, confirming mitochondrial cell death pathways; in contrast, 4-phenylbutyric acid, which improves ER folding capacity did not protect FC-loaded hepatocytes. HMGB1 was released into the culture medium of FC-loaded wild type (WT) but not Jnk1(-/-) or Tlr4(-/-) hepatocytes, while anti-HMGB1 anti-serum prevented JNK activation and FC lipotoxicity in WT hepatocytes. CONCLUSIONS These novel findings show that mitochondrial FC deposition causes hepatocyte apoptosis and necrosis by activating JNK1; inhibition of which could be a novel therapeutic approach in NASH. Further, there is a tight link between JNK1-dependent HMGB1 secretion from lipotoxic hepatocytes and a paracrine cytolytic effect on neighbouring cholesterol-loaded hepatocytes operating via TLR4.
Collapse
Affiliation(s)
- Lay T Gan
- Liver Research Group, Australian National University (ANU) Medical School at The Canberra Hospital, Garran, ACT, Australia
| | - Derrick M Van Rooyen
- Liver Research Group, Australian National University (ANU) Medical School at The Canberra Hospital, Garran, ACT, Australia
| | - Mark E Koina
- Department of Anatomical Pathology, ACT Pathology, The Canberra Hospital, ACT, Australia
| | - Robert S McCuskey
- Department of Cellular and Molecular Medicine, College of Medicine, University of Arizona, USA
| | - Narcissus C Teoh
- Liver Research Group, Australian National University (ANU) Medical School at The Canberra Hospital, Garran, ACT, Australia
| | - Geoffrey C Farrell
- Liver Research Group, Australian National University (ANU) Medical School at The Canberra Hospital, Garran, ACT, Australia.
| |
Collapse
|
188
|
Mitochondrial cholesterol: mechanisms of import and effects on mitochondrial function. J Bioenerg Biomembr 2014; 48:137-51. [PMID: 25425472 DOI: 10.1007/s10863-014-9592-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 11/14/2014] [Indexed: 12/23/2022]
Abstract
Mitochondria require cholesterol for biogenesis and membrane maintenance, and for the synthesis of steroids, oxysterols and hepatic bile acids. Multiple pathways mediate the transport of cholesterol from different subcellular pools to mitochondria. In steroidogenic cells, the steroidogenic acute regulatory protein (StAR) interacts with a mitochondrial protein complex to mediate cholesterol delivery to the inner mitochondrial membrane for conversion to pregnenolone. In non-steroidogenic cells, several members of a protein family defined by the presence of a StAR-related lipid transfer (START) domain play key roles in the delivery of cholesterol to mitochondrial membranes. Subdomains of the endoplasmic reticulum (ER), termed mitochondria-associated ER membranes (MAM), form membrane contact sites with mitochondria and may contribute to the transport of ER cholesterol to mitochondria, either independently or in conjunction with lipid-transfer proteins. Model systems of mitochondria enriched with cholesterol in vitro and mitochondria isolated from cells with (patho)physiological mitochondrial cholesterol accumulation clearly demonstrate that mitochondrial cholesterol levels affect mitochondrial function. Increased mitochondrial cholesterol levels have been observed in several diseases, including cancer, ischemia, steatohepatitis and neurodegenerative diseases, and influence disease pathology. Hence, a deeper understanding of the mechanisms maintaining mitochondrial cholesterol homeostasis may reveal additional targets for therapeutic intervention. Here we give a brief overview of mitochondrial cholesterol import in steroidogenic cells, and then focus on cholesterol trafficking pathways that deliver cholesterol to mitochondrial membranes in non-steroidogenic cells. We also briefly discuss the consequences of increased mitochondrial cholesterol levels on mitochondrial function and their potential role in disease pathology.
Collapse
|
189
|
Enhanced gastrointestinal expression of cytosolic malic enzyme (ME1) induces intestinal and liver lipogenic gene expression and intestinal cell proliferation in mice. PLoS One 2014; 9:e113058. [PMID: 25402228 PMCID: PMC4234650 DOI: 10.1371/journal.pone.0113058] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 10/19/2014] [Indexed: 12/12/2022] Open
Abstract
The small intestine participates in lipid digestion, metabolism and transport. Cytosolic malic enzyme 1 (ME1) is an enzyme that generates NADPH used in fatty acid and cholesterol biosynthesis. Previous work has correlated liver and adipose ME1 expression with susceptibility to obesity and diabetes; however, the contributions of intestine-expressed ME1 to these conditions are unknown. We generated transgenic (Tg) mice expressing rat ME1 in the gastrointestinal epithelium under the control of the murine villin1 promoter/enhancer. Levels of intestinal ME1 protein (endogenous plus transgene) were greater in Tg than wildtype (WT) littermates. Effects of elevated intestinal ME1 on body weight, circulating insulin, select adipocytokines, blood glucose, and metabolism-related genes were examined. Male Tg mice fed a high-fat (HF) diet gained significantly more body weight than WT male littermates and had heavier livers. ME1-Tg mice had deeper intestinal and colon crypts, a greater intestinal 5-bromodeoxyuridine labeling index, and increased expression of intestinal lipogenic (Fasn, Srebf1) and cholesterol biosynthetic (Hmgcsr, Hmgcs1), genes. The livers from HF diet-fed Tg mice also exhibited an induction of cholesterol and lipogenic pathway genes and altered measures (Irs1, Irs2, Prkce) of insulin sensitivity. Results indicate that gastrointestinal ME1 via its influence on intestinal epithelial proliferation, and lipogenic and cholesterologenic genes may concomitantly impact signaling in liver to modify this tissue’s metabolic state. Our work highlights a new mouse model to address the role of intestine-expressed ME1 in whole body metabolism, hepatomegaly, and crypt cell proliferation. Intestinal ME1 may thus constitute a therapeutic target to reduce obesity-associated pathologies.
Collapse
|
190
|
Männistö VT, Simonen M, Soininen P, Tiainen M, Kangas AJ, Kaminska D, Venesmaa S, Käkelä P, Kärjä V, Gylling H, Ala-Korpela M, Pihlajamäki J. Lipoprotein subclass metabolism in nonalcoholic steatohepatitis. J Lipid Res 2014; 55:2676-84. [PMID: 25344588 DOI: 10.1194/jlr.p054387] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Nonalcoholic steatohepatitis (NASH) is associated with increased synthesis of triglycerides and cholesterol coupled with increased VLDL synthesis in the liver. In addition, increased cholesterol content in the liver associates with NASH. Here we study the association of lipoprotein subclass metabolism with NASH. To this aim, liver biopsies from 116 morbidly obese individuals [age 47.3 ± 8.7 (mean ± SD) years, BMI 45.1 ± 6.1 kg/m², 39 men and 77 women] were used for histological assessment. Proton NMR spectroscopy was used to measure lipid concentrations of 14 lipoprotein subclasses in native serum samples at baseline and after obesity surgery. We observed that total lipid concentration of VLDL and LDL subclasses, but not HDL subclasses, associated with NASH [false discovery rate (FDR) < 0.1]. More specifically, total lipid and cholesterol concentration of VLDL and LDL subclasses associated with inflammation, fibrosis, and cell injury (FDR < 0.1), independent of steatosis. Cholesterol concentration of all VLDL subclasses also correlated with total and free cholesterol content in the liver. All NASH-related changes in lipoprotein subclasses were reversed by obesity surgery. High total lipid and cholesterol concentration of serum VLDL and LDL subclasses are linked to cholesterol accumulation in the liver and to liver cell injury in NASH.
Collapse
Affiliation(s)
- Ville T Männistö
- Department of Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Marko Simonen
- Department of Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Pasi Soininen
- NMR Metabolomics Laboratory, School of Pharmacy, University of Eastern Finland, Kuopio, Finland Computational Medicine, Institute of Health Sciences, University of Oulu, Oulu, Finland
| | - Mika Tiainen
- NMR Metabolomics Laboratory, School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Antti J Kangas
- Computational Medicine, Institute of Health Sciences, University of Oulu, Oulu, Finland
| | - Dorota Kaminska
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
| | - Sari Venesmaa
- Department of Surgery, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Pirjo Käkelä
- Department of Surgery, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Vesa Kärjä
- Department of Pathology, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Helena Gylling
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland Department of Medicine, Division of Internal Medicine, University of Helsinki, Helsinki, Finland
| | - Mika Ala-Korpela
- NMR Metabolomics Laboratory, School of Pharmacy, University of Eastern Finland, Kuopio, Finland Computational Medicine, Institute of Health Sciences, University of Oulu, Oulu, Finland Department of Medicine, Oulu University Hospital, Oulu, Finland Computational Medicine, School of Social and Community Medicine and the Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol, UK
| | - Jussi Pihlajamäki
- Department of Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland Clinical Nutrition and Obesity Center, Kuopio University Hospital, Kuopio, Finland
| |
Collapse
|
191
|
Nonalcoholic Fatty liver disease: pathogenesis and therapeutics from a mitochondria-centric perspective. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:637027. [PMID: 25371775 PMCID: PMC4211163 DOI: 10.1155/2014/637027] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 07/31/2014] [Accepted: 07/31/2014] [Indexed: 12/12/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) describes a spectrum of disorders characterized by the accumulation of triglycerides within the liver. The global prevalence of NAFLD has been increasing as the obesity epidemic shows no sign of relenting. Mitochondria play a central role in hepatic lipid metabolism and also are affected by upstream signaling pathways involved in hepatic metabolism. This review will focus on the role of mitochondria in the pathophysiology of NAFLD and touch on some of the therapeutic approaches targeting mitochondria as well as metabolically important signaling pathways. Mitochondria are able to adapt to lipid accumulation in hepatocytes by increasing rates of beta-oxidation; however increased substrate delivery to the mitochondrial electron transport chain (ETC) leads to increased reactive oxygen species (ROS) production and eventually ETC dysfunction. Decreased ETC function combined with increased rates of fatty acid beta-oxidation leads to the accumulation of incomplete products of beta-oxidation, which combined with increased levels of ROS contribute to insulin resistance. Several related signaling pathways, nuclear receptors, and transcription factors also regulate hepatic lipid metabolism, many of which are redox sensitive and regulated by ROS.
Collapse
|
192
|
Wolf MJ, Adili A, Piotrowitz K, Abdullah Z, Boege Y, Stemmer K, Ringelhan M, Simonavicius N, Egger M, Wohlleber D, Lorentzen A, Einer C, Schulz S, Clavel T, Protzer U, Thiele C, Zischka H, Moch H, Tschöp M, Tumanov AV, Haller D, Unger K, Karin M, Kopf M, Knolle P, Weber A, Heikenwalder M. Metabolic activation of intrahepatic CD8+ T cells and NKT cells causes nonalcoholic steatohepatitis and liver cancer via cross-talk with hepatocytes. Cancer Cell 2014; 26:549-64. [PMID: 25314080 DOI: 10.1016/j.ccell.2014.09.003] [Citation(s) in RCA: 506] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 07/28/2014] [Accepted: 09/17/2014] [Indexed: 12/13/2022]
Abstract
Hepatocellular carcinoma (HCC), the fastest rising cancer in the United States and increasing in Europe, often occurs with nonalcoholic steatohepatitis (NASH). Mechanisms underlying NASH and NASH-induced HCC are largely unknown. We developed a mouse model recapitulating key features of human metabolic syndrome, NASH, and HCC by long-term feeding of a choline-deficient high-fat diet. This induced activated intrahepatic CD8(+) T cells, NKT cells, and inflammatory cytokines, similar to NASH patients. CD8(+) T cells and NKT cells but not myeloid cells promote NASH and HCC through interactions with hepatocytes. NKT cells primarily cause steatosis via secreted LIGHT, while CD8(+) and NKT cells cooperatively induce liver damage. Hepatocellular LTβR and canonical NF-κB signaling facilitate NASH-to-HCC transition, demonstrating that distinct molecular mechanisms determine NASH and HCC development.
Collapse
Affiliation(s)
- Monika Julia Wolf
- Institute of Surgical Pathology, University Hospital Zurich, Zurich 8091, Switzerland
| | - Arlind Adili
- Institute of Virology, Technische Universität München and Helmholtz Zentrum München, Munich 81675, Germany
| | - Kira Piotrowitz
- LIMES Life and Medical Sciences Institute, University of Bonn, Bonn 53125, Germany
| | - Zeinab Abdullah
- Institutes of Molecular Medicine and Experimental Immunology, University of Bonn, Bonn 53105, Germany
| | - Yannick Boege
- Institute of Surgical Pathology, University Hospital Zurich, Zurich 8091, Switzerland
| | - Kerstin Stemmer
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München & Division of Metabolic Diseases, Technische Universität München, Munich 81657, Germany
| | - Marc Ringelhan
- Institute of Virology, Technische Universität München and Helmholtz Zentrum München, Munich 81675, Germany; Second Medical Department, Klinikum Rechts der Isar, Technische Universität München, Munich 81657, Germany
| | - Nicole Simonavicius
- Institute of Virology, Technische Universität München and Helmholtz Zentrum München, Munich 81675, Germany
| | - Michèle Egger
- Institute of Surgical Pathology, University Hospital Zurich, Zurich 8091, Switzerland
| | - Dirk Wohlleber
- Institute of Molecular Immunology, Technische Universität München, Munich 81675, Germany
| | - Anna Lorentzen
- Institute of Virology, Technische Universität München and Helmholtz Zentrum München, Munich 81675, Germany
| | - Claudia Einer
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg 85764, Germany
| | - Sabine Schulz
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg 85764, Germany
| | - Thomas Clavel
- Junior Group Intestinal Microbiome, Technische Universität München, Freising-Weihenstephan 85350, Germany; Chair of Nutrition and Immunology, ZIEL-Research Center for Nutrition and Food Sciences, Biofunctionality Unit, Technische Universität München, Freising-Weihenstephan 85350, Germany
| | - Ulrike Protzer
- Institute of Virology, Technische Universität München and Helmholtz Zentrum München, Munich 81675, Germany
| | - Christoph Thiele
- LIMES Life and Medical Sciences Institute, University of Bonn, Bonn 53125, Germany
| | - Hans Zischka
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg 85764, Germany
| | - Holger Moch
- Institute of Surgical Pathology, University Hospital Zurich, Zurich 8091, Switzerland
| | - Matthias Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München & Division of Metabolic Diseases, Technische Universität München, Munich 81657, Germany
| | | | - Dirk Haller
- Chair of Nutrition and Immunology, ZIEL-Research Center for Nutrition and Food Sciences, Biofunctionality Unit, Technische Universität München, Freising-Weihenstephan 85350, Germany
| | - Kristian Unger
- Research Unit of Radiation Cytogenetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg 85764, Germany
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, University of California, San Diego, School of Medicine, San Diego, CA 92093, USA
| | - Manfred Kopf
- Molecular Biomedicine, Institute of Molecular Health Sciences, ETH Zurich, Zurich 8093, Switzerland
| | - Percy Knolle
- Institutes of Molecular Medicine and Experimental Immunology, University of Bonn, Bonn 53105, Germany; Institute of Molecular Immunology, Technische Universität München, Munich 81675, Germany
| | - Achim Weber
- Institute of Surgical Pathology, University Hospital Zurich, Zurich 8091, Switzerland.
| | - Mathias Heikenwalder
- Institute of Virology, Technische Universität München and Helmholtz Zentrum München, Munich 81675, Germany.
| |
Collapse
|
193
|
Machado MV, Cortez-Pinto H. Non-alcoholic fatty liver disease: what the clinician needs to know. World J Gastroenterol 2014; 20:12956-80. [PMID: 25278691 PMCID: PMC4177476 DOI: 10.3748/wjg.v20.i36.12956] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 04/21/2014] [Accepted: 05/25/2014] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most frequent cause of liver disease in the Western world. Furthermore, it is increasing worldwide, paralleling the obesity pandemic. Though highly frequent, only about one fifth of affected subjects are at risk of developing the progressive form of the disease, non-alcoholic steatohepatitis with fibrosis. Even in the latter, liver disease is slowly progressive, though, since it is so prevalent, it is already the third cause of liver transplantation in the United States, and it is predicted to get to the top of the ranking in few years. Of relevance, fatty liver is also associated with increased overall mortality and particularly increased cardiovascular mortality. The literature and amount of published papers on NAFLD is increasing as fast as its prevalence, which makes it difficult to keep updated in this topic. This review aims to summarize the latest knowledge on NAFLD, in order to help clinicians understanding its pathogenesis and advances on diagnosis and treatment.
Collapse
|
194
|
Chen Y, Varghese Z, Ruan XZ. The molecular pathogenic role of inflammatory stress in dysregulation of lipid homeostasis and hepatic steatosis. Genes Dis 2014; 1:106-112. [PMID: 30258859 PMCID: PMC6150078 DOI: 10.1016/j.gendis.2014.07.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 07/20/2014] [Indexed: 02/07/2023] Open
Abstract
Non-alcoholic Fatty Liver Disease (NAFLD) is becoming the leading cause of chronic liver injury in developed countries and China. Chronic systemic inflammation plays a decisive role and is fundamental in the progression of NAFLD from simple steatosis (SS) toward higher risk nonalcoholic steatohepatitis (NASH) states. However, the exact mechanisms by which inflammation leading to NASH are incompletely understood. In this review, we focus the role of the cross talk between inflammation and lipid homeostasis on the progression of NAFLD.
Collapse
Affiliation(s)
- Yaxi Chen
- Centre for Lipid Research, Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Zac Varghese
- John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, London, UK
| | - Xiong Z Ruan
- Centre for Lipid Research, Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China.,John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, London, UK
| |
Collapse
|
195
|
Wang Y, Tong J, Chang B, Wang BF, Zhang D, Wang BY. Relationship of SREBP-2 rs2228314 G>C polymorphism with nonalcoholic fatty liver disease in a Han Chinese population. Genet Test Mol Biomarkers 2014; 18:653-7. [PMID: 24992162 DOI: 10.1089/gtmb.2014.0116] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE This study aims at investigating the relationship of SREBP-2 rs2228314 G>C polymorphism with the risk of nonalcoholic fatty liver disease (NAFLD) in a Han Chinese population. METHOD This case-control study was conducted at the First Affiliated Hospital of China Medical University. Three-hundred subjects who met the diagnostic criteria of NAFLD and had typical clinical and ultrasonographic findings were placed in the case group. There were 160 matched healthy controls in the control group. A common single nucleotide polymorphism (SNP) (rs2228314 G>C) in the SREBP-2 gene was tested. Genetic analyses were performed using genomic DNA extracted from peripheral blood leukocytes. Polymerase chain reaction-restriction fragment length polymorphism was applied to detect SNP. RESULTS Our results indicated that the GG genotype and G carrier (CG+GG) of rs2228314 G>C polymorphism in the SREBP-2 gene were strongly associated with susceptibility to NAFLD (both p<0.001). However, there was no significant difference in the frequency of G allele between NAFLD patients and healthy controls (p=0.328). Multivariate logistic regression analysis revealed that GG genotype, G carrier, body mass index, high-density lipoprotein cholesterol, total cholesterol, alanine aminotransferase, and γ-glutamyl-transferase might be associated with an increased risk of NAFLD (all p<0.05). CONCLUSION The results of this study provide evidence that the GG genotype and G carrier (CG+GG) of rs2228314 G>C polymorphism in the SREBP-2 gene may increase the risk of NAFLD.
Collapse
Affiliation(s)
- Ying Wang
- Department of Gastroenterology, The First Affiliated Hospital of China Medical University , Shenyang, People's Republic of China
| | | | | | | | | | | |
Collapse
|
196
|
Ribas V, García-Ruiz C, Fernández-Checa JC. Glutathione and mitochondria. Front Pharmacol 2014; 5:151. [PMID: 25024695 PMCID: PMC4079069 DOI: 10.3389/fphar.2014.00151] [Citation(s) in RCA: 352] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 06/10/2014] [Indexed: 12/16/2022] Open
Abstract
Glutathione (GSH) is the main non-protein thiol in cells whose functions are dependent on the redox-active thiol of its cysteine moiety that serves as a cofactor for a number of antioxidant and detoxifying enzymes. While synthesized exclusively in the cytosol from its constituent amino acids, GSH is distributed in different compartments, including mitochondria where its concentration in the matrix equals that of the cytosol. This feature and its negative charge at physiological pH imply the existence of specific carriers to import GSH from the cytosol to the mitochondrial matrix, where it plays a key role in defense against respiration-induced reactive oxygen species and in the detoxification of lipid hydroperoxides and electrophiles. Moreover, as mitochondria play a central strategic role in the activation and mode of cell death, mitochondrial GSH has been shown to critically regulate the level of sensitization to secondary hits that induce mitochondrial membrane permeabilization and release of proteins confined in the intermembrane space that once in the cytosol engage the molecular machinery of cell death. In this review, we summarize recent data on the regulation of mitochondrial GSH and its role in cell death and prevalent human diseases, such as cancer, fatty liver disease, and Alzheimer’s disease.
Collapse
Affiliation(s)
- Vicent Ribas
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona, Consejo Superior de Investigaciones Científicas (IIBB-CSIC) Barcelona, Spain ; Liver Unit, Hospital Clínic, Centre Esther Koplowitz, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)-Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) Barcelona, Spain
| | - Carmen García-Ruiz
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona, Consejo Superior de Investigaciones Científicas (IIBB-CSIC) Barcelona, Spain ; Liver Unit, Hospital Clínic, Centre Esther Koplowitz, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)-Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) Barcelona, Spain ; Research Center for Alcoholic Liver and Pancreatic Diseases and Cirrhosis, Keck School of Medicine, University of Southern California Los Angeles, CA, USA
| | - José C Fernández-Checa
- Department of Cell Death and Proliferation, Institute of Biomedical Research of Barcelona, Consejo Superior de Investigaciones Científicas (IIBB-CSIC) Barcelona, Spain ; Liver Unit, Hospital Clínic, Centre Esther Koplowitz, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)-Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) Barcelona, Spain ; Research Center for Alcoholic Liver and Pancreatic Diseases and Cirrhosis, Keck School of Medicine, University of Southern California Los Angeles, CA, USA
| |
Collapse
|
197
|
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the liver disease of this century, increasing in parallel with obesity, insulin resistance and the metabolic syndrome. NAFLD can be seen as a component of the metabolic syndrome, and as such, contributing as a risk factor for cardiovascular disease. In fact, these patients die more often from cardiovascular disease than from direct consequences of liver disease. In this review, we will summarize the data that link NAFLD as a central player in this dysmetabolism, as well as the evidence for appropriate therapy, in order to improve not only liver disease prognosis, but also the overall prognosis and risk of mortality, with particular focus on cardiovascular risk.
Collapse
Affiliation(s)
- Mariana Verdelho Machado
- Departamento de Gastrenterologia, Hospital Santa Maria, CHLN, Unidade de Nutrição e Metabolismo, Faculdade de Medicina de Lisboa, IMM, Lisbon, Portugal
| | | |
Collapse
|
198
|
Steatosis and steatohepatitis: complex disorders. Int J Mol Sci 2014; 15:9924-44. [PMID: 24897026 PMCID: PMC4100130 DOI: 10.3390/ijms15069924] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/01/2014] [Accepted: 05/20/2014] [Indexed: 12/20/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) which includes steatosis and steatohepatitis, in particular non-alcoholic steatohepatitis (NASH), is a rising health problem world-wide and should be separated from alcoholic steatohepatitis (ASH). NAFLD is regarded as hepatic manifestation of the metabolic syndrome (MetSy), being tightly linked to obesity and type 2 diabetes mellitus (T2DM). Development of steatosis, liver fibrosis and cirrhosis often progresses towards hepatocellular carcinogenesis and frequently results in the indication for liver transplantation, underlining the clinical significance of this disease complex. Work on different murine models and several human patients studies led to the identification of different molecular key players as well as epigenetic factors like miRNAs and SNPs, which have a promoting or protecting function in AFLD/ASH or NAFLD/NASH. To which extent they might be translated into human biology and pathogenesis is still questionable and needs further investigation regarding diagnostic parameters, drug development and a better understanding of the genetic impact. In this review we give an overview about the currently available knowledge and recent findings regarding the development and progression of this disease.
Collapse
|
199
|
Laggai S, Kessler SM, Boettcher S, Lebrun V, Gemperlein K, Lederer E, Leclercq IA, Mueller R, Hartmann RW, Haybaeck J, Kiemer AK. The IGF2 mRNA binding protein p62/IGF2BP2-2 induces fatty acid elongation as a critical feature of steatosis. J Lipid Res 2014; 55:1087-97. [PMID: 24755648 DOI: 10.1194/jlr.m045500] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Indexed: 12/12/2022] Open
Abstract
Liver-specific overexpression of the insulin-like growth factor 2 (IGF2) mRNA binding protein p62/IGF2BP2-2 induces a fatty liver, which highly expresses IGF2 Because IGF2 expression is elevated in patients with steatohepatitis, the aim of our study was to elucidate the role and interconnection of p62 and IGF2 in lipid metabolism. Expression of p62 and IGF2 highly correlated in human liver disease. p62 induced an elevated ratio of C18:C16 and increased fatty acid elongase 6 (ELOVL6) protein, the enzyme catalyzing the elongation of C16 to C18 fatty acids and promoting nonalcoholic steatohepatitis in mice and humans. The p62 overexpression induced the activation of the ELOVL6 transcriptional activator sterol regulatory element binding transcription factor 1 (SREBF1). Recombinant IGF2 induced the nuclear translocation of SREBF1 and a neutralizing IGF2 antibody reduced ELOVL6 and mature SREBF1 protein levels. Concordantly, p62 and IGF2 correlated with ELOVL6 in human livers. Decreased palmitoyl-CoA levels, as found in p62 transgenic livers, can explain the lipogenic action of ELOVL6. Accordingly, p62 represents an inducer of hepatic C18 fatty acid production via a SREBF1-dependent induction of ELOVL6. These findings underline the detrimental role of p62 in liver disease.
Collapse
Affiliation(s)
- Stephan Laggai
- Department of Pharmacy, Pharmaceutical Biology, Department of Pharmacy, Pharmaceutical, Saarland University, Saarbrücken, Germany
| | - Sonja M Kessler
- Department of Pharmacy, Pharmaceutical Biology, Department of Pharmacy, Pharmaceutical, Saarland University, Saarbrücken, Germany Medicinal Chemistry, Saarland University, Saarbrücken, Germany Laboratory of Hepato-gastroenterology, Institut de Recherche expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | | | - Valérie Lebrun
- Laboratory of Hepato-gastroenterology, Institut de Recherche expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Katja Gemperlein
- Department of Pharmacy, Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany
| | - Eva Lederer
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Isabelle A Leclercq
- Laboratory of Hepato-gastroenterology, Institut de Recherche expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Rolf Mueller
- Department of Pharmacy, Pharmaceutical Biotechnology, Saarland University, Saarbrücken, Germany Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany
| | - Rolf W Hartmann
- Medicinal Chemistry, Saarland University, Saarbrücken, Germany Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany
| | | | - Alexandra K Kiemer
- Department of Pharmacy, Pharmaceutical Biology, Department of Pharmacy, Pharmaceutical, Saarland University, Saarbrücken, Germany
| |
Collapse
|
200
|
Finch ML, Marquardt JU, Yeoh GC, Callus BA. Regulation of microRNAs and their role in liver development, regeneration and disease. Int J Biochem Cell Biol 2014; 54:288-303. [PMID: 24731940 DOI: 10.1016/j.biocel.2014.04.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 03/25/2014] [Accepted: 04/03/2014] [Indexed: 12/12/2022]
Abstract
Since their discovery more than a decade ago microRNAs have been demonstrated to have profound effects on almost every aspect of biology. Numerous studies in recent years have shown that microRNAs have important roles in development and in the etiology and progression of disease. This review is focused on microRNAs and the roles they play in liver development, regeneration and liver disease; particularly chronic liver diseases such as alcoholic liver disease, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, viral hepatitis and primary liver cancer. The key microRNAs identified in liver development and chronic liver disease will be discussed together with, where possible, the target messenger RNAs that these microRNAs regulate to profoundly alter these processes. This article is part of a Directed Issue entitled: The Non-coding RNA Revolution.
Collapse
Affiliation(s)
- Megan L Finch
- School of Chemistry and Biochemistry, University of Western Australia, Crawley 6009, WA, Australia.
| | - Jens U Marquardt
- Department of Medicine I, Johannes Gutenberg University, Mainz, Germany.
| | - George C Yeoh
- School of Chemistry and Biochemistry, University of Western Australia, Crawley 6009, WA, Australia; Harry Perkins Institute of Medical Research, Nedlands 6000, WA, Australia.
| | - Bernard A Callus
- School of Chemistry and Biochemistry, University of Western Australia, Crawley 6009, WA, Australia.
| |
Collapse
|