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Evason KJ, Francisco MT, Juric V, Balakrishnan S, Lopez Pazmino MDP, Gordan JD, Kakar S, Spitsbergen J, Goga A, Stainier DYR. Identification of Chemical Inhibitors of β-Catenin-Driven Liver Tumorigenesis in Zebrafish. PLoS Genet 2015; 11:e1005305. [PMID: 26134322 PMCID: PMC4489858 DOI: 10.1371/journal.pgen.1005305] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 05/28/2015] [Indexed: 12/19/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is one of the most lethal human cancers. The search for targeted treatments has been hampered by the lack of relevant animal models for the genetically diverse subsets of HCC, including the 20-40% of HCCs that are defined by activating mutations in the gene encoding β-catenin. To address this chemotherapeutic challenge, we created and characterized transgenic zebrafish expressing hepatocyte-specific activated β-catenin. By 2 months post fertilization (mpf), 33% of transgenic zebrafish developed HCC in their livers, and 78% and 80% of transgenic zebrafish showed HCC at 6 and 12 mpf, respectively. As expected for a malignant process, transgenic zebrafish showed significantly decreased mean adult survival compared to non-transgenic control siblings. Using this novel transgenic model, we screened for druggable pathways that mediate β-catenin-induced liver growth and identified two c-Jun N-terminal kinase (JNK) inhibitors and two antidepressants (one tricyclic antidepressant, amitriptyline, and one selective serotonin reuptake inhibitor) that suppressed this phenotype. We further found that activated β-catenin was associated with JNK pathway hyperactivation in zebrafish and in human HCC. In zebrafish larvae, JNK inhibition decreased liver size specifically in the presence of activated β-catenin. The β-catenin-specific growth-inhibitory effect of targeting JNK was conserved in human liver cancer cells. Our other class of hits, antidepressants, has been used in patient treatment for decades, raising the exciting possibility that these drugs could potentially be repurposed for cancer treatment. In support of this proposal, we found that amitriptyline decreased tumor burden in a mouse HCC model. Our studies implicate JNK inhibitors and antidepressants as potential therapeutics for β-catenin-induced liver tumors. Liver cancer is a leading cause of cancer-related death. Genetic analysis of liver cancer has enabled classification of these tumors into subsets with unique genetic, clinical, and prognostic features. The search for targeted liver cancer treatments has been hampered by the lack of relevant animal models for these genetically diverse subsets, including liver cancers that are defined by activating mutations in the gene encoding β-catenin, an integral component of the Wnt signaling pathway. Here we describe the generation and characterization of genetically modified zebrafish expressing hepatocyte-specific activated β-catenin. We used this new zebrafish model to screen for drugs that suppress β-catenin-induced liver growth, and identified two classes of hits, c-Jun N-terminal kinase (JNK) inhibitors and antidepressants, that suppressed this phenotype. Our findings provide insights into the mechanisms by which β-catenin promotes liver tumor formation and implicate JNK inhibitors and antidepressants as potential treatments for a subset of human liver cancers.
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Affiliation(s)
- Kimberley J. Evason
- Department of Pathology, University of California, San Francisco, San Francisco, California, United States of America
- Department of Biochemistry and Biophysics, Programs in Developmental and Stem Cell Biology, Genetics and Human Genetics, Diabetes Center, Institute for Regeneration Medicine and the Liver Center, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail: (KJE); (AG); (DYRS)
| | - Macrina T. Francisco
- Department of Pathology, University of California, San Francisco, San Francisco, California, United States of America
- Department of Cell & Tissue Biology, University of California, San Francisco, San Francisco, California, United States of America
| | - Vladislava Juric
- The George Williams Hooper Research Foundation, University of California, San Francisco, San Francisco, California, United States of America
| | - Sanjeev Balakrishnan
- Department of Cell & Tissue Biology, University of California, San Francisco, San Francisco, California, United States of America
| | - Maria del Pilar Lopez Pazmino
- Department of Biochemistry and Biophysics, Programs in Developmental and Stem Cell Biology, Genetics and Human Genetics, Diabetes Center, Institute for Regeneration Medicine and the Liver Center, University of California, San Francisco, San Francisco, California, United States of America
| | - John D. Gordan
- Department of Medicine, University of California, San Francisco, San Francisco, California, United States of America
| | - Sanjay Kakar
- Department of Pathology, University of California, San Francisco, San Francisco, California, United States of America
| | - Jan Spitsbergen
- Department of Microbiology, Oregon State University, Corvallis, Oregon, United States of America
| | - Andrei Goga
- Department of Cell & Tissue Biology, University of California, San Francisco, San Francisco, California, United States of America
- Department of Medicine, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail: (KJE); (AG); (DYRS)
| | - Didier Y. R. Stainier
- Department of Biochemistry and Biophysics, Programs in Developmental and Stem Cell Biology, Genetics and Human Genetics, Diabetes Center, Institute for Regeneration Medicine and the Liver Center, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail: (KJE); (AG); (DYRS)
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302
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Liu Q, Rehman H, Krishnasamy Y, Schnellmann RG, Lemasters JJ, Zhong Z. Improvement of liver injury and survival by JNK2 and iNOS deficiency in liver transplants from cardiac death mice. J Hepatol 2015; 63:68-74. [PMID: 25703084 PMCID: PMC4475508 DOI: 10.1016/j.jhep.2015.02.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 02/09/2015] [Accepted: 02/11/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND & AIMS Inclusion of liver grafts from cardiac death donors (CDD) would increase the availability of donor livers but is hampered by a higher risk of primary non-function. Here, we seek to determine mechanisms that contribute to primary non-function of liver grafts from CDD with the goal to develop strategies for improved function and outcome, focusing on c-Jun-N-terminal kinase (JNK) activation and mitochondrial depolarization, two known mediators of graft failure. METHODS Livers explanted from wild-type, inducible nitric oxide synthase knockout (iNOS(-/-)), JNK1(-/-) or JNK2(-/-) mice after 45-min aorta clamping were implanted into wild-type recipients. Mitochondrial depolarization was detected by intravital confocal microscopy in living recipients. RESULTS After transplantation of wild-type CDD livers, graft iNOS expression and 3-nitrotyrosine adducts increased, but hepatic endothelial NOS expression was unchanged. Graft injury and dysfunction were substantially higher in CDD grafts than in non-CDD grafts. iNOS deficiency and inhibition attenuated injury and improved function and survival of CDD grafts. JNK1/2 and apoptosis signal-regulating kinase-1 activation increased markedly in wild-type CDD grafts, which was blunted by iNOS deficiency. JNK inhibition and JNK2 deficiency, but not JNK1 deficiency, decreased injury and improved function and survival of CDD grafts. Mitochondrial depolarization and binding of phospho-JNK2 to Sab, a mitochondrial protein linked to the mitochondrial permeability transition, were higher in CDD than in non-CDD grafts. iNOS deficiency, JNK inhibition and JNK2 deficiency all decreased mitochondrial depolarization and blunted ATP depletion in CDD grafts. JNK inhibition and deficiency did not decrease 3-nitrotyrosine adducts in CDD grafts. CONCLUSION The iNOS-JNK2-Sab pathway promotes CDD graft failure via increased mitochondrial depolarization, and is an attractive target to improve liver function and survival in CDD liver transplantation recipients.
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Affiliation(s)
- Qinlong Liu
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, United States; The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province, China
| | - Hasibur Rehman
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Yasodha Krishnasamy
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Rick G Schnellmann
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, United States; Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29403, United States
| | - John J Lemasters
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, United States; Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Zhi Zhong
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, United States.
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303
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Kim YH, Hwang JH, Kim KS, Noh JR, Choi DH, Kim DK, Tadi S, Yim YH, Choi HS, Lee CH. Metformin ameliorates acetaminophen hepatotoxicity via Gadd45β-dependent regulation of JNK signaling in mice. J Hepatol 2015; 63:75-82. [PMID: 25681557 DOI: 10.1016/j.jhep.2015.02.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 02/03/2015] [Accepted: 02/05/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS Acetaminophen (APAP) overdose is a leading cause of drug-induced acute liver failure. Prolonged c-Jun N-terminal kinase (JNK) activation plays a central role in APAP-induced liver injury and growth arrest, and DNA damage-inducible 45 beta (Gadd45β) is known to inhibit JNK phosphorylation. Metformin has recently been shown to have hepatoprotective effects. The aim of the present study is to investigate whether metformin mitigates APAP-induced hepatotoxicity and to ascertain the molecular basis of this effect. METHODS We used APAP- and/or metformin-treated Gadd45β knockout (KO) mice and wild type (WT) C57BL/6J control mice. Primary mouse hepatocytes were isolated from WT and Gadd45β KO mice were used for in vitro study. RESULTS Metformin pretreatment protected against APAP toxicity with decreased liver damage, and inhibited APAP-induced prolonged hepatic JNK phosphorylation in WT mice. Gadd45β expression was increased after APAP treatment, and the expression of Gadd45β was further enhanced by metformin. The effects of metformin on APAP-induced liver injury and JNK phosphorylation were abolished in Gadd45β KO mice. Notably, subtoxic doses of APAP caused cell death and sustained JNK phosphorylation in Gadd45β-deficient primary hepatocytes. In parallel, APAP increased mortality, severe liver injury, and JNK activation in Gadd45β KO mice. Interestingly, metformin administered after APAP treatment protected against APAP-evoked hepatotoxicity in WT mice, but not in Gadd45β KO mice. CONCLUSIONS This study is the first to demonstrate that metformin shows protective and therapeutic effects against APAP overdose-evoked hepatotoxicity via Gadd45β-dependent JNK regulation. Metformin would be a promising therapeutic strategy for treatment of APAP overdose.
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Affiliation(s)
- Yong-Hoon Kim
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon 305-806, South Korea
| | - Jung Hwan Hwang
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon 305-806, South Korea
| | - Kyoung-Shim Kim
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon 305-806, South Korea
| | - Jung-Ran Noh
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon 305-806, South Korea
| | - Dong-Hee Choi
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon 305-806, South Korea
| | - Don-Kyu Kim
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea
| | - Surendar Tadi
- Korea Research Institute of Standards and Science, Daejeon, South Korea
| | - Yong-Hyeon Yim
- Korea Research Institute of Standards and Science, Daejeon, South Korea
| | - Hueng-Sik Choi
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea
| | - Chul-Ho Lee
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon 305-806, South Korea.
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304
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Song BJ, Akbar M, Jo I, Hardwick JP, Abdelmegeed MA. Translational Implications of the Alcohol-Metabolizing Enzymes, Including Cytochrome P450-2E1, in Alcoholic and Nonalcoholic Liver Disease. ADVANCES IN PHARMACOLOGY 2015; 74:303-72. [PMID: 26233911 DOI: 10.1016/bs.apha.2015.04.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Fat accumulation (hepatic steatosis) in alcoholic and nonalcoholic fatty liver disease is a potentially pathologic condition which can progress to steatohepatitis (inflammation), fibrosis, cirrhosis, and carcinogenesis. Many clinically used drugs or some alternative medicine compounds are also known to cause drug-induced liver injury, which can further lead to fulminant liver failure and acute deaths in extreme cases. During liver disease process, certain cytochromes P450 such as the ethanol-inducible cytochrome P450-2E1 (CYP2E1) and CYP4A isozymes can be induced and/or activated by alcohol and/or high-fat diets and pathophysiological conditions such as fasting, obesity, and diabetes. Activation of these P450 isozymes, involved in the metabolism of ethanol, fatty acids, and various drugs, can produce reactive oxygen/nitrogen species directly and/or indirectly, contributing to oxidative modifications of DNA/RNA, proteins and lipids. In addition, aldehyde dehydrogenases including the mitochondrial low Km aldehyde dehydrogenase-2 (ALDH2), responsible for the metabolism of acetaldehyde and lipid aldehydes, can be inactivated by various hepatotoxic agents. These highly reactive acetaldehyde and lipid peroxides, accumulated due to ALDH2 suppression, can interact with cellular macromolecules DNA/RNA, lipids, and proteins, leading to suppression of their normal function, contributing to DNA mutations, endoplasmic reticulum stress, mitochondrial dysfunction, steatosis, and cell death. In this chapter, we specifically review the roles of the alcohol-metabolizing enzymes including the alcohol dehydrogenase, ALDH2, CYP2E1, and other enzymes in promoting liver disease. We also discuss translational research opportunities with natural and/or synthetic antioxidants, which can prevent or delay the onset of inflammation and liver disease.
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Affiliation(s)
- Byoung-Joon Song
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA.
| | - Mohammed Akbar
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA
| | - Inho Jo
- Department of Molecular Medicine, Ewha Womans University School of Medicine, Seoul, South Korea
| | - James P Hardwick
- Biochemistry and Molecular Pathology in Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Mohamed A Abdelmegeed
- Section of Molecular Pharmacology and Toxicology, Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA
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305
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Lipoapoptosis induced by saturated free fatty acids stimulates monocyte migration: a novel role for Pannexin1 in liver cells. Purinergic Signal 2015; 11:347-59. [PMID: 26054298 DOI: 10.1007/s11302-015-9456-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 05/27/2015] [Indexed: 02/07/2023] Open
Abstract
Recruitment of monocytes in the liver is a key pathogenic feature of hepatic inflammation in nonalcoholic steatohepatitis (NASH), but the mechanisms involved are poorly understood. Here, we studied migration of human monocytes in response to supernatants obtained from liver cells after inducing lipoapoptosis with saturated free fatty acids (FFA). Lipoapoptotic supernatants stimulated monocyte migration with the magnitude similar to a monocyte chemoattractant protein, CCL2 (MCP-1). Inhibition of c-Jun NH2-terminal kinase (JNK) in liver cells with SP600125 blocked migration of monocytes in a dose-dependent manner, indicating that JNK stimulates release of chemoattractants in lipoapoptosis. Notably, treatment of supernatants with Apyrase to remove ATP potently inhibited migration of THP-1 monocytes and partially blocked migration of primary human monocytes. Inhibition of the CCL2 receptor (CCR2) on THP-1 monocytes with RS102895, a specific CCR2 inhibitor, did not block migration induced by lipoapoptotic supernatants. Consistent with these findings, lipoapoptosis stimulated pathophysiological extracellular ATP (eATP) release that increased supernatant eATP concentration from 5 to ~60 nM. Importantly, inhibition of Panx1 expression in liver cells with short hairpin RNA (shRNA) decreased supernatant eATP concentration and inhibited monocyte migration, indicating that monocyte migration is mediated in part by Panx1-dependent eATP release. Moreover, JNK inhibition decreased supernatant eATP concentration and inhibited Pannexin1 activation, as determined by YoPro-1 uptake in liver cells in a dose-dependent manner. These results suggest that JNK regulates activation of Panx1 channels, and provide evidence that Pannexin1-dependent pathophysiological eATP release in lipoapoptosis is capable of stimulating migration of human monocytes, and may participate in the recruitment of monocytes in chronic liver injury induced by saturated FFA.
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306
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Xie J, Liu J, Chen TM, Lan Q, Zhang QY, Liu B, Dai D, Zhang WD, Hu LP, Zhu RZ. Dihydromyricetin alleviates carbon tetrachloride-induced acute liver injury via JNK-dependent mechanism in mice. World J Gastroenterol 2015; 21:5473-5481. [PMID: 25987769 PMCID: PMC4427668 DOI: 10.3748/wjg.v21.i18.5473] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 12/31/2014] [Accepted: 02/13/2015] [Indexed: 02/06/2023] Open
Abstract
AIM: To assess the effects of dihydromyricetin (DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride (CCl4) treatment.
METHODS: C57 BL/6 mice were used in this study. Mice were orally administered with DHM (150 mg/kg) for 4 d after CCl4 treatment. Serum and liver tissue samples were collected on days 1, 2, 3, 5 and 7 after CCl4 treatment. The anti-inflammatory effect of DHM was assessed directly by hepatic histology detection and indirectly by serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, and superoxide dismutase (SOD). Inflammatory cytokines, such as interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), were detected using ELISA kits. Proliferating cell nuclear antigen (PCNA) staining was used to evaluate the role of DHM in promoting hepatocyte proliferation. Hepatocyte apoptosis was measured by TUNEL assay. Furthermore, apoptosis proteins Caspases-3, 6, 8, and 9 were detected by Western blot. SP600125 were used to confirm whether DHM regulated liver regeneration through JNK/TNF-α pathways.
RESULTS: DHM showed a strong anti-inflammatory effect on CCl4-induced liver injury in mice. DHM could significantly decrease serum ALT, AST, IL-1β, IL-6 and TNF-α and increase serum albumin, SOD and liver SOD compared to the control group after CCl4 treatment (P < 0.05). PCNA results indicated that DHM could significantly increase the number of PCNA positive cells compared to the control (348.9 ± 56.0 vs 107.1 ± 31.4, P < 0.01). TUNEL assay showed that DHM dramatically reduced the number of apoptotic cells after CCl4 treatment compared to the control (365.4 ± 99.4 vs 90.5±13.8, P < 0.01). Caspase activity detection showed that DHM could reduce the activities of Caspases- 8, 3, 6 and 9 compared to the control (P < 0.05). The results of Western blot showed that DHM increased the expression of JNK and decreased TNF-α expression. However, DHM could not affect TNF-α expression after SP600125 treatment. Furthermore, DHM could significantly improve the survival rate of acute liver failure (ALF) mice (73.3% vs 20.0%, P < 0.0001), and SP600125 could inhibit the effect of DHM.
CONCLUSION: These findings demonstrate that DHM alleviates CCl4-induced liver injury, suggesting that DHM is a promising candidate for reversing liver injury and ALF.
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MESH Headings
- Animals
- Anti-Inflammatory Agents/pharmacology
- Biomarkers/blood
- Carbon Tetrachloride
- Caspase Inhibitors/pharmacology
- Cell Proliferation/drug effects
- Chemical and Drug Induced Liver Injury/blood
- Chemical and Drug Induced Liver Injury/drug therapy
- Chemical and Drug Induced Liver Injury/enzymology
- Chemical and Drug Induced Liver Injury/pathology
- Cytochromes c/metabolism
- Disease Models, Animal
- Flavonols/pharmacology
- Inflammation Mediators/blood
- JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors
- JNK Mitogen-Activated Protein Kinases/metabolism
- Liver/drug effects
- Liver/enzymology
- Liver/pathology
- Liver Failure, Acute/blood
- Liver Failure, Acute/chemically induced
- Liver Failure, Acute/drug therapy
- Liver Failure, Acute/enzymology
- Liver Failure, Acute/pathology
- Liver Regeneration/drug effects
- Male
- Mice, Inbred C57BL
- Mitochondria, Liver/drug effects
- Mitochondria, Liver/enzymology
- Mitochondria, Liver/pathology
- Protein Kinase Inhibitors/pharmacology
- Signal Transduction/drug effects
- Time Factors
- Tumor Necrosis Factor-alpha/blood
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307
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Mujaibel LM, Kilarkaje N. Mitogen-activated protein kinase signaling and its association with oxidative stress and apoptosis in lead-exposed hepatocytes. ENVIRONMENTAL TOXICOLOGY 2015; 30:513-529. [PMID: 24293362 DOI: 10.1002/tox.21928] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 11/13/2013] [Accepted: 11/20/2013] [Indexed: 06/02/2023]
Abstract
Lead toxicity has become a serious public health concern all over the world. Previous studies have shown that lead induces biochemical and structural changes in liver. However, although lead is known to alter liver functions, the underlying molecular mechanisms of hepatotoxicity are not yet clear. We hypothesized that a correlation exists between oxidative stress, apoptosis and mitogen-activated protein kinases (MAPKs) in lead-exposed liver. Wistar rats were treated with 0, 0.5%, and 1% lead acetate for 3d, 14d, and 35d and sacrificed the next day. On 4d, oxidative stress and apoptosis were correlated with downregulated expressions of ERK1/2 and p38-MAPKα/β, and upregulated expressions of JNK1/3 in males. In females, the correlation was with downregulated expressions of ERK1/2 and upregulated expressions of p38-MAPKα/β and JNK1/3. On 15d, the correlation was observed with upregulated expressions of p38-MAPKα/β in males and downregulated expressions of p38-MAPKα/β in females. In both sexes, a correlation was observed with upregulated expressions of ERK1/2 and JNK1/3 in 1% groups. On 36d, the correlation was observed with downregulated expressions of p38-MAPKα/β in males and their upregulated expressions in females. Time-dependent increase in lipid peroxidation on 15d and 36d correlated with upregulated expressions of p38-MAPKα/β in females and ERK1/2 in 1% groups in both sexes. The lower dose induced more apoptosis up to 15d in females and the higher dose induced in males on 36d. Generally, the female livers had more p38-MAPKα/β than the male livers. On 36d, the female livers showed more p38-MAPKα/β and JNK1/3 than the male livers. In conclusion, although not clearly defined, a correlation exists among oxidative stress, apoptosis, and the MAPKs in lead-exposed hepatocytes. The sex-dependent effects may be due to differences in hormonal or other physiological mechanisms. In lead-exposed hepatocytes, the apoptosis may be induced via oxidative stress-mediated alterations in the MAPKs.
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308
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Abascal F, Tress ML, Valencia A. The evolutionary fate of alternatively spliced homologous exons after gene duplication. Genome Biol Evol 2015; 7:1392-403. [PMID: 25931610 PMCID: PMC4494069 DOI: 10.1093/gbe/evv076] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Alternative splicing and gene duplication are the two main processes responsible for expanding protein functional diversity. Although gene duplication can generate new genes and alternative splicing can introduce variation through alternative gene products, the interplay between the two processes is complex and poorly understood. Here, we have carried out a study of the evolution of alternatively spliced exons after gene duplication to better understand the interaction between the two processes. We created a manually curated set of 97 human genes with mutually exclusively spliced homologous exons and analyzed the evolution of these exons across five distantly related vertebrates (lamprey, spotted gar, zebrafish, fugu, and coelacanth). Most of these exons had an ancient origin (more than 400 Ma). We found examples supporting two extreme evolutionary models for the behaviour of homologous axons after gene duplication. We observed 11 events in which gene duplication was accompanied by splice isoform separation, that is, each paralog specifically conserved just one distinct ancestral homologous exon. At other extreme, we identified genes in which the homologous exons were always conserved within paralogs, suggesting that the alternative splicing event cannot easily be separated from the function in these genes. That many homologous exons fall in between these two extremes highlights the diversity of biological systems and suggests that the subtle balance between alternative splicing and gene duplication is adjusted to the specific cellular context of each gene.
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Affiliation(s)
- Federico Abascal
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Michael L Tress
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Alfonso Valencia
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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309
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Aminotriazole alleviates acetaminophen poisoning via downregulating P450 2E1 and suppressing inflammation. PLoS One 2015; 10:e0122781. [PMID: 25884831 PMCID: PMC4401561 DOI: 10.1371/journal.pone.0122781] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 02/14/2015] [Indexed: 12/13/2022] Open
Abstract
Aminotriazole (ATZ) is commonly used as a catalase (CAT) inhibitor. We previously found ATZ attenuated oxidative liver injury, but the underlying mechanisms remain unknown. Acetaminophen (APAP) overdose frequently induces life-threatening oxidative hepatitis. In the present study, the potential hepatoprotective effects of ATZ on oxidative liver injury and the underlying mechanisms were further investigated in a mouse model with APAP poisoning. The experimental data indicated that pretreatment with ATZ dose- and time-dependently suppressed the elevation of plasma aminotransferases in APAP exposed mice, these effects were accompanied with alleviated histological abnormality and improved survival rate of APAP-challenged mice. In mice exposed to APAP, ATZ pretreatment decreased the CAT activities, hydrogen peroxide (H2O2) levels, malondialdehyde (MDA) contents, myeloperoxidase (MPO) levels in liver and reduced TNF-α levels in plasma. Pretreatment with ATZ also downregulated APAP-induced cytochrome P450 2E1 (CYP2E1) expression and JNK phosphorylation. In addition, posttreatment with ATZ after APAP challenge decreased the levels of plasma aminotransferases and increased the survival rate of experimental animals. Posttreatment with ATZ had no effects on CYP2E1 expression or JNK phosphorylation, but it significantly decreased the levels of plasma TNF-α. Our data indicated that the LD50 of ATZ in mice was 5367.4 mg/kg body weight, which is much higher than the therapeutic dose of ATZ in the present study. These data suggested that ATZ might be effective and safe in protect mice against APAP-induced hepatotoxicity, the beneficial effects might resulted from downregulation of CYP2E1 and inhibiton of inflammation.
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310
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Nagaoka K, Hino S, Sakamoto A, Anan K, Takase R, Umehara T, Yokoyama S, Sasaki Y, Nakao M. Lysine-specific demethylase 2 suppresses lipid influx and metabolism in hepatic cells. Mol Cell Biol 2015; 35:1068-80. [PMID: 25624347 PMCID: PMC4355535 DOI: 10.1128/mcb.01404-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 12/12/2014] [Accepted: 01/21/2015] [Indexed: 01/04/2023] Open
Abstract
Cells link environmental fluctuations, such as nutrition, to metabolic remodeling. Epigenetic factors are thought to be involved in such cellular processes, but the molecular basis remains unclear. Here we report that the lysine-specific demethylase 2 (LSD2) suppresses the flux and metabolism of lipids to maintain the energy balance in hepatic cells. Using transcriptome and chromatin immunoprecipitation-sequencing analyses, we revealed that LSD2 represses the genes involved in lipid influx and metabolism through demethylation of histone H3K4. Selective recruitment of LSD2 at lipid metabolism gene loci was mediated in part by a stress-responsive transcription factor, c-Jun. Intriguingly, LSD2 depletion increased the intracellular levels of many lipid metabolites, which was accompanied by an increased susceptibility to toxic cell damage in response to fatty acid exposure. Our data demonstrate that LSD2 maintains metabolic plasticity under fluctuating environment in hepatocytes by mediating the cross talk between the epigenome and metabolism.
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Affiliation(s)
- Katsuya Nagaoka
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan Department of Gastroenterology and Hepatology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Shinjiro Hino
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Akihisa Sakamoto
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Kotaro Anan
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Ryuta Takase
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Takashi Umehara
- RIKEN Systems and Structural Biology Center, Yokohama, Japan
| | | | - Yutaka Sasaki
- Department of Gastroenterology and Hepatology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Mitsuyoshi Nakao
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Tokyo, Japan
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311
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Che Q, Lin L, Ai Q, Ge P, Dai J, Jiang R, Zhou D, Wan J, Zhang L. Caloric restriction mimetic 2-deoxyglucose alleviated lethal liver injury induced by lipopolysaccharide/D-galactosamine in mice. Biochem Biophys Res Commun 2015; 459:541-6. [PMID: 25749337 DOI: 10.1016/j.bbrc.2015.02.145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 02/25/2015] [Indexed: 12/18/2022]
Abstract
The glycolytic inhibitor 2-deoxyglucose (2-DG) is a calorie restriction (CR) mimetic produces CR-like beneficial effects in both acute and chronic pathological processes, but whether 2-DG is also helpful in critical and life-threatening situation is not known. In the present study, the potential benefits of 2-DG in lipopolysaccharide/D-galactosamine (LPS/D-Gal)-induced lethal liver injury were investigated. The results indicated that treatment with 2-DG suppressed the elevation of plasma aminotransferases, alleviated the histopathological abnormalities and improved the survival rate of LPS/D-Gal-exposed mice. Treatment with 2-DG also suppressed the production of pro-apoptotic cytokine TNF-α, the phosphorylation of JNK, the activation of caspase cascade and the count of TUNEL-positive apoptotic hepatocytes. These data suggested that the CR mimetic 2-DG could also provide beneficial effects in lethal pathological process such as LPS/D-Gal-induced fulminant liver injury.
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Affiliation(s)
- Qian Che
- Department of Pathophysiology, Chongqing Medical University, Chongqing, China
| | - Ling Lin
- Department of Pathophysiology, Chongqing Medical University, Chongqing, China
| | - Qing Ai
- Department of Physiology, Chongqing Medical University, Chongqing, China
| | - Pu Ge
- Department of Pathophysiology, Chongqing Medical University, Chongqing, China
| | - Jie Dai
- Hospital of Chongqing University of Arts and Sciences, Chongqing, China
| | - Rong Jiang
- Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing, China
| | - Dan Zhou
- Department of Pathophysiology, Chongqing Medical University, Chongqing, China
| | - Jingyuan Wan
- Department of Pharmacology, Chongqing Medical University, Chongqing, China
| | - Li Zhang
- Department of Pathophysiology, Chongqing Medical University, Chongqing, China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing, China.
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312
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Seki E, Schwabe RF. Hepatic inflammation and fibrosis: functional links and key pathways. Hepatology 2015; 61:1066-79. [PMID: 25066777 PMCID: PMC4306641 DOI: 10.1002/hep.27332] [Citation(s) in RCA: 657] [Impact Index Per Article: 73.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 07/16/2014] [Indexed: 02/06/2023]
Abstract
Inflammation is one of the most characteristic features of chronic liver disease of viral, alcoholic, fatty, and autoimmune origin. Inflammation is typically present in all disease stages and associated with the development of fibrosis, cirrhosis, and hepatocellular carcinoma. In the past decade, numerous studies have contributed to improved understanding of the links between hepatic inflammation and fibrosis. Here, we review mechanisms that link inflammation with the development of liver fibrosis, focusing on the role of inflammatory mediators in hepatic stellate cell (HSC) activation and HSC survival during fibrogenesis and fibrosis regression. We will summarize the contributions of different inflammatory cells, including hepatic macrophages, T and B lymphocytes, natural killer cells and platelets, as well as key effectors, such as cytokines, chemokines, and damage-associated molecular patterns. Furthermore, we will discuss the relevance of inflammatory signaling pathways for clinical liver disease and for the development of antifibrogenic strategies.
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Affiliation(s)
- Ekihiro Seki
- Department of Medicine, University of California, San Diego, School
of Medicine, La Jolla, CA 92093, USA,Surgery, University of California, San Diego, School of Medicine, La
Jolla, CA 92093, USA
| | - Robert F. Schwabe
- Department of Medicine, Columbia University, College of Physicians
and Surgeons, New York, NY 10032, USA,Institute of Human Nutrition, Columbia University, College of
Physicians and Surgeons, New York, NY 10032, USA
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313
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Lonardo A, Ballestri S, Marchesini G, Angulo P, Loria P. Nonalcoholic fatty liver disease: a precursor of the metabolic syndrome. Dig Liver Dis 2015; 47:181-90. [PMID: 25739820 DOI: 10.1016/j.dld.2014.09.020] [Citation(s) in RCA: 481] [Impact Index Per Article: 53.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 09/19/2014] [Accepted: 09/21/2014] [Indexed: 02/07/2023]
Abstract
The conventional paradigm of nonalcoholic fatty liver disease representing the "hepatic manifestation of the metabolic syndrome" is outdated. We identified and summarized longitudinal studies that, supporting the association of nonalcoholic fatty liver disease with either type 2 diabetes mellitus or metabolic syndrome, suggest that nonalcoholic fatty liver disease precedes the development of both conditions. Online Medical databases were searched, relevant articles were identified, their references were further assessed and tabulated data were checked. Although several cross-sectional studies linked nonalcoholic fatty liver disease to either diabetes and other components of the metabolic syndrome, we focused on 28 longitudinal studies which provided evidence for nonalcoholic fatty liver disease as a risk factor for the future development of diabetes. Moreover, additional 19 longitudinal reported that nonalcoholic fatty liver disease precedes and is a risk factor for the future development of the metabolic syndrome. Finally, molecular and genetic studies are discussed supporting the view that aetiology of steatosis and lipid intra-hepatocytic compartmentation are a major determinant of whether fatty liver is/is not associated with insulin resistance and metabolic syndrome. Data support the novel paradigm of nonalcoholic fatty liver disease as a strong determinant for the development of the metabolic syndrome, which has potentially relevant clinical implications for diagnosing, preventing and treating metabolic syndrome.
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Affiliation(s)
- Amedeo Lonardo
- AUSL Modena and University of Modena and Reggio Emilia, Department of Biomedical, Metabolic and Neural Sciences, Division of Internal Medicine, NOCSAE - Baggiovara, Modena, Italy.
| | - Stefano Ballestri
- AUSL Modena, Department of Internal Medicine, Division of Internal Medicine, Hospital of Pavullo, Pavullo nel Frignano, Italy
| | - Giulio Marchesini
- "Alma Mater Studiorum" University, Unit of Metabolic Diseases and Clinical Dietetics, Bologna, Italy
| | - Paul Angulo
- University of Kentucky, Division of Digestive Diseases & Nutrition, Section of Hepatology, Medical Center, Lexington, KY, USA
| | - Paola Loria
- AUSL Modena and University of Modena and Reggio Emilia, Department of Biomedical, Metabolic and Neural Sciences, Division of Internal Medicine, NOCSAE - Baggiovara, Modena, Italy
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314
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Compromised MAPK signaling in human diseases: an update. Arch Toxicol 2015; 89:867-82. [PMID: 25690731 DOI: 10.1007/s00204-015-1472-2] [Citation(s) in RCA: 720] [Impact Index Per Article: 80.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 02/09/2015] [Indexed: 02/08/2023]
Abstract
The mitogen-activated protein kinases (MAPKs) in mammals include c-Jun NH2-terminal kinase (JNK), p38 MAPK, and extracellular signal-regulated kinase (ERK). These enzymes are serine-threonine protein kinases that regulate various cellular activities including proliferation, differentiation, apoptosis or survival, inflammation, and innate immunity. The compromised MAPK signaling pathways contribute to the pathology of diverse human diseases including cancer and neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. The JNK and p38 MAPK signaling pathways are activated by various types of cellular stress such as oxidative, genotoxic, and osmotic stress as well as by proinflammatory cytokines such as tumor necrosis factor-α and interleukin 1β. The Ras-Raf-MEK-ERK signaling pathway plays a key role in cancer development through the stimulation of cell proliferation and metastasis. The p38 MAPK pathway contributes to neuroinflammation mediated by glial cells including microglia and astrocytes, and it has also been associated with anticancer drug resistance in colon and liver cancer. We here summarize recent research on the roles of MAPK signaling pathways in human diseases, with a focus on cancer and neurodegenerative conditions.
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315
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Schaefer FM, Peng J, Hu W, Drvarov O, Nevzorova YA, Zhao G, Masaoudi MA, Davis RJ, Trautwein C, Cubero FJ. Bone marrow-derived c-jun N-terminal kinase-1 (JNK1) mediates liver regeneration. Biochim Biophys Acta Mol Basis Dis 2015; 1852:137-45. [DOI: 10.1016/j.bbadis.2014.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/10/2014] [Accepted: 10/15/2014] [Indexed: 01/24/2023]
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316
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Lutz A, Sanwald J, Thomas M, Feuer R, Sawodny O, Ederer M, Borner C, Humar M, Merfort I. Interleukin-1β enhances FasL-induced caspase-3/-7 activity without increasing apoptosis in primary mouse hepatocytes. PLoS One 2014; 9:e115603. [PMID: 25551609 PMCID: PMC4281199 DOI: 10.1371/journal.pone.0115603] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 12/01/2014] [Indexed: 11/18/2022] Open
Abstract
Sustained inflammation may increase the susceptibility of hepatocytes to apoptotic cell death and therefore exacerbate liver damage. Here we report that the pro-inflammatory cytokine IL-1β sensitizes primary murine hepatocytes to Fas ligand (FasL)-induced caspase-3/-7 activity. This process was dependent on JNK1/2 and the BH3-only proteins Bim and Bid. Mathematical modeling revealed that incubation of hepatocytes with IL-1β depleted the anti-apoptotic Bcl-2 protein pool and thus shifted hepatocytes to mitochondrial type II apoptosis following Fas activation. As a consequence, IL-1β and FasL treatment enhanced cytochrome c release. Surprisingly, despite increased caspase-3/-7 activation, FasL-induced cell death was reduced by IL-1β pre-treatment. This protective effect was independent of JNK1/2, Bim or Bid. Furthermore, elevated caspase-3/-7 activity upon IL-1β and FasL treatment did not result in enhanced PARP cleavage. The protective effect of IL-1β was seen after 3 h of pre-incubation, indicating an anti-apoptotic transcriptional response. Indeed, NF-κB DNA binding was increased in response to IL-1β plus FasL and gene-expression profiling of NF-κB regulated genes revealed a transcriptional and translational upregulation of the caspase-8 inhibitor A20. A mathematical model was developed to explain the contradictious occurrence of both increased caspase-3/-7 activity and elevated cell viability by including a heterogeneous distribution of Bcl-2 proteins and variations in Fas signaling resulting in different subpopulations of hepatocytes.
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Affiliation(s)
- Anna Lutz
- Department of Pharmaceutical Biology and Biotechnology, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Julia Sanwald
- Institute for System Dynamics, University of Stuttgart, Stuttgart, Germany
| | - Maria Thomas
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany
| | - Ronny Feuer
- Institute for System Dynamics, University of Stuttgart, Stuttgart, Germany
| | - Oliver Sawodny
- Institute for System Dynamics, University of Stuttgart, Stuttgart, Germany
| | - Michael Ederer
- Institute for System Dynamics, University of Stuttgart, Stuttgart, Germany
| | - Christoph Borner
- Institute of Molecular Medicine and Cell Research, Albert Ludwigs University Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), Albert Ludwigs University Freiburg, Freiburg, Germany
- Bioss – Centre for Biological Signaling Studies, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Matjaz Humar
- Department of Pharmaceutical Biology and Biotechnology, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Irmgard Merfort
- Department of Pharmaceutical Biology and Biotechnology, Albert Ludwigs University Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), Albert Ludwigs University Freiburg, Freiburg, Germany
- * E-mail:
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317
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Quetier I, Brezillon N, Revaud J, Ahodantin J, DaSilva L, Soussan P, Kremsdorf D. C-terminal-truncated hepatitis B virus X protein enhances the development of diethylnitrosamine-induced hepatocellular carcinogenesis. J Gen Virol 2014; 96:614-625. [PMID: 25519169 DOI: 10.1099/vir.0.070680-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hepatitis B virus X protein (HBx) is involved in the development of hepatocellular carcinoma (HCC). The HBx sequence is a preferential site of integration into the human genome, leading to the formation of C-terminal-truncated HBx proteins (Ct-HBx). We previously reported that Ct-HBx proteins were able to potentiate cell transformation in vitro. Our present goal was to compare the ability of Ct-HBx and full-length HBx (FL-HBx) proteins to develop or enhance HCC in transgenic mice. In the absence of treatment, neither Ct-HBx- nor FL-HBx-transgenic mice developed HCC. In young mice treated with diethylnitrosamine (DEN) at 8 months of age, a significantly higher incidence and number of liver lesions were observed in Ct-HBx mice than in FL-HBx and control mice. The earlier development of tumours in Ct-HBx-transgenic mice was associated with increased liver inflammation. At 10 months, macroscopic and microscopic analyses showed that, statistically, FL-HBx mice developed more liver lesions with a larger surface area than control mice. Furthermore, during DEN-induced initiation of HCC, Ct-HBx- and FL-HBx-transgenic mice showed higher expression of IL-6, TNF-α and IL-1β transcripts, activation of STAT3, ERK and JNK proteins and an increase in cell apoptosis. In conclusion, in DEN-treated transgenic mice, the expression of Ct-HBx protein causes a more rapid onset of HCC than does FL-HBx protein. HBV genome integration leading to the expression of a truncated form of HBx protein may therefore facilitate HCC development in chronically infected patients.
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Affiliation(s)
- Ivan Quetier
- Institut Pasteur, Département de Virologie, Paris, France
- Université Paris Descartes, Sorbonne Paris-Cité, Faculté de Médecine Necker, Paris, France
- Inserm, U845, Team 'Pathogenèse des hépatites virales B et immunothérapie', Paris, France
| | - Nicolas Brezillon
- Université Paris Descartes, Sorbonne Paris-Cité, Faculté de Médecine Necker, Paris, France
- Inserm, U845, Team 'Pathogenèse des hépatites virales B et immunothérapie', Paris, France
- Institut Pasteur, Département de Virologie, Paris, France
| | - Julien Revaud
- Institut Pasteur, Département de Virologie, Paris, France
- Université Paris Descartes, Sorbonne Paris-Cité, Faculté de Médecine Necker, Paris, France
- Inserm, U845, Team 'Pathogenèse des hépatites virales B et immunothérapie', Paris, France
| | - James Ahodantin
- Institut Pasteur, Département de Virologie, Paris, France
- Université Paris Descartes, Sorbonne Paris-Cité, Faculté de Médecine Necker, Paris, France
- Inserm, U845, Team 'Pathogenèse des hépatites virales B et immunothérapie', Paris, France
| | - Lucie DaSilva
- Institut Pasteur, Département de Virologie, Paris, France
- Université Paris Descartes, Sorbonne Paris-Cité, Faculté de Médecine Necker, Paris, France
- Inserm, U845, Team 'Pathogenèse des hépatites virales B et immunothérapie', Paris, France
| | - Patrick Soussan
- Université Paris Descartes, Sorbonne Paris-Cité, Faculté de Médecine Necker, Paris, France
- Institut Pasteur, Département de Virologie, Paris, France
- Service de Virologie, Hôpital Tenon, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Inserm, U845, Team 'Pathogenèse des hépatites virales B et immunothérapie', Paris, France
| | - Dina Kremsdorf
- Institut Pasteur, Département de Virologie, Paris, France
- Université Paris Descartes, Sorbonne Paris-Cité, Faculté de Médecine Necker, Paris, France
- Inserm, U845, Team 'Pathogenèse des hépatites virales B et immunothérapie', Paris, France
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318
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Abstract
The c-Jun N-terminal kinases (JNKs) are serine/threonine kinases implicated in the pathogenesis of various diseases. Recent advances in the development of novel inhibitors of JNKs will be reviewed. Significant progress in the design of JNK inhibitors displaying selectivity versus other kinases has been achieved within the past 4 years. However, the development of isoform selective JNK inhibitors is still an open task.
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Affiliation(s)
- Pierre Koch
- Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical Sciences, Eberhard Karls Universität Tübingen , Auf der Morgenstelle 8, 72076 Tübingen, Germany
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319
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Yao J, Zhao Y, Zhang J, Hong Y, Lu H, Wu J. Serum amylase levels are decreased in Chinese non-alcoholic fatty liver disease patients. Lipids Health Dis 2014; 13:185. [PMID: 25481429 PMCID: PMC4267431 DOI: 10.1186/1476-511x-13-185] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 12/01/2014] [Indexed: 02/06/2023] Open
Abstract
Background Low serum amylase levels have been reported in patients with metabolic
syndrome (MS), diabetes, and asymptomatic non-alcoholic fatty liver disease
(NAFLD). However, no study has yet indicated the serum amylase levels in NAFLD
with MS. The aim of the present study was to evaluate serum amylase levels in
NAFLD patients with and without MS, and to explore a possible association between
serum amylase levels with the components of MS and the degree of hepatic fibrosis
in NAFLD patients. Methods Our study included 713 NAFLD participants (180 females and 533 males) and 304
healthy control participants (110 females and 194 males). The diagnosis of NAFLD
was based on ultrasonography, and advanced fibrosis was assessed by the FIB-4
index. Results Serum amylase levels were significantly lower in NAFLD patients with MS
compared with NAFLD patients without MS and healthy controls (42, 45, and 53 IU/L,
respectively). The serum amylase levels of patients with elevated glucose,
elevated triglycerides, and low high density lipoprotein cholesterol patients were
significantly lower than in case of normal parameters (both p < 0.05).
Multivariate logistic regression analysis showed that a relative serum amylase
level increase was an independent factor predicting advanced fibrosis (FIB-4 ≥1.3)
in NAFLD participants (OR: 1.840, 95% CI: 1.117-3.030, p=0.017). Conclusions Compared with NAFLD patients without MS and healthy controls, serum amylase
levels were significantly lower in NAFLD patients with MS. Moreover, a relative
serum amylase increase may be an independent factor of more advanced hepatic
fibrosis.
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Affiliation(s)
| | | | - Juanwen Zhang
- Department of Laboratory Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, 79 QingChun Road, Hangzhou 310003, Zhejiang Province, People's Republic of China.
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320
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Muth F, Günther M, Bauer SM, Döring E, Fischer S, Maier J, Drückes P, Köppler J, Trappe J, Rothbauer U, Koch P, Laufer SA. Tetra-Substituted Pyridinylimidazoles As Dual Inhibitors of p38α Mitogen-Activated Protein Kinase and c-Jun N-Terminal Kinase 3 for Potential Treatment of Neurodegenerative Diseases. J Med Chem 2014; 58:443-56. [DOI: 10.1021/jm501557a] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Felix Muth
- Department
of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical
Sciences, Eberhard Karls Universität Tübingen, Auf
der Morgenstelle 8, 72076 Tübingen, Germany
| | - Marcel Günther
- Department
of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical
Sciences, Eberhard Karls Universität Tübingen, Auf
der Morgenstelle 8, 72076 Tübingen, Germany
| | - Silke M. Bauer
- Department
of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical
Sciences, Eberhard Karls Universität Tübingen, Auf
der Morgenstelle 8, 72076 Tübingen, Germany
| | - Eva Döring
- Department
of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical
Sciences, Eberhard Karls Universität Tübingen, Auf
der Morgenstelle 8, 72076 Tübingen, Germany
| | - Sabine Fischer
- Department
of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical
Sciences, Eberhard Karls Universität Tübingen, Auf
der Morgenstelle 8, 72076 Tübingen, Germany
| | - Julia Maier
- Natural
and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse
55, 72770 Reutlingen, Germany
| | | | | | - Jörg Trappe
- Novartis Pharma AG, CH-4002 Basel, Switzerland
| | - Ulrich Rothbauer
- Natural
and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse
55, 72770 Reutlingen, Germany
| | - Pierre Koch
- Department
of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical
Sciences, Eberhard Karls Universität Tübingen, Auf
der Morgenstelle 8, 72076 Tübingen, Germany
| | - Stefan A. Laufer
- Department
of Pharmaceutical and Medicinal Chemistry, Institute of Pharmaceutical
Sciences, Eberhard Karls Universität Tübingen, Auf
der Morgenstelle 8, 72076 Tübingen, Germany
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321
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Zhang B, Roh YS, Liang S, Liu C, Naiki M, Masuda K, Seki E. Neurotropin suppresses inflammatory cytokine expression and cell death through suppression of NF-κB and JNK in hepatocytes. PLoS One 2014; 9:e114071. [PMID: 25470242 PMCID: PMC4254918 DOI: 10.1371/journal.pone.0114071] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 11/03/2014] [Indexed: 02/06/2023] Open
Abstract
Inflammatory response and cell death in hepatocytes are hallmarks of chronic liver disease, and, therefore, can be effective therapeutic targets. Neurotropin® (NTP) is a drug widely used in Japan and China to treat chronic pain. Although NTP has been demonstrated to suppress chronic pain through the descending pain inhibitory system, the action mechanism of NTP remains elusive. We hypothesize that NTP functions to suppress inflammatory pathways, thereby attenuating disease progression. In the present study, we investigated whether NTP suppresses inflammatory signaling and cell death pathways induced by interleukin-1β (IL-1β) and tumor necrosis factor-α (TNFα) in hepatocytes. NTP suppressed nuclear factor-κB (NF-κB) activation induced by IL-1β and TNFα assessed by using hepatocytes isolated from NF-κB-green fluorescent protein (GFP) reporter mice and an NF-κB-luciferase reporter system. The expression of NF-κB target genes, Il6, Nos2, Cxcl1, ccl5 and Cxcl2 induced by IL-1β and TNFα was suppressed after NTP treatment. We also found that NTP suppressed the JNK phosphorylation induced by IL-1β and TNFα. Because JNK activation contributes to hepatocyte death, we determined that NTP treatment suppressed hepatocyte death induced by IL-1β and TNFα in combination with actinomycin D. Taken together, our data demonstrate that NTP attenuates IL-1β and TNFα-mediated inflammatory cytokine expression and cell death in hepatocytes through the suppression of NF-κB and JNK. The results from the present study suggest that NTP may become a preventive or therapeutic strategy for alcoholic and non-alcoholic fatty liver disease in which NF-κB and JNK are thought to take part.
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Affiliation(s)
- Bi Zhang
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Yoon Seok Roh
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Shuang Liang
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Cheng Liu
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Mitsuru Naiki
- Department of Pharmacological Research, Institute of Bio-Active Science, Nippon Zoki Pharmaceutical Company Ltd., Kato, Hyogo, Japan
| | - Koichi Masuda
- Department of Orthopaedic Surgery, School of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Ekihiro Seki
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California, United States of America
- Department of Surgery, School of Medicine, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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322
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Wang T, Takikawa Y, Watanabe A, Kakisaka K, Oikawa K, Miyamoto Y, Suzuki K. Proliferation of mouse liver stem/progenitor cells induced by plasma from patients with acute liver failure is modulated by P2Y2 receptor-mediated JNK activation. J Gastroenterol 2014; 49:1557-66. [PMID: 24362969 DOI: 10.1007/s00535-013-0927-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 12/09/2013] [Indexed: 02/04/2023]
Abstract
BACKGROUND We recently reported that acute liver failure plasma (ALF-P) promotes the proliferation of mouse liver oval cells (OCs) through c-jun N-terminal kinase (JNK) activation. The aim of this study was to investigate the mechanism by which ALF-P induces JNK activation and OC proliferation. METHODS OCs and primary hepatocytes were exposed to ALF-P or normal control plasma (NC-P). Cell proliferation and activation of JNK and other JNK signaling molecules were detected subsequently. Next, we determined the effects of extracellular adenosine triphosphate (ATP) and ATP receptors on ALF-P-stimulated cell growth. Finally, the relationship between the tumor necrosis factor alpha (TNFα) and ATP receptor pathways was investigated. RESULTS Cell proliferation accompanied by JNK activation was only observed in ALF-P-stimulated OCs. ALF-P stimulated the activation of SEK1/MKK4 and ATF2, but not c-Jun. Both PPADS (pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid) treatment and P2Y2 (G-protein-coupled) small interfering RNA (siRNA) transfection blocked the effects of ALF-P on cell proliferation and JNK activation. However, ATP levels in ALF-P were significantly lower than that in NC-P, and ATP did not stimulate the proliferation of OCs. On the other hand, TNFα stimulated JNK activation and proliferation of OCs. TNFα receptor antagonist partly inhibited the ALF-P-stimulated proliferation of OCs. Moreover, PPADS significantly inhibited TNFα-stimulated cell proliferation, induced apoptosis, and inhibited the activation of JNK. However, our data showed no significant difference in plasma TNFα levels between the NC-P and ALF-P samples. CONCLUSIONS JNK activation induced by P2Y2 receptor crosstalk with the TNFα signaling pathway is important in mediating the effects of ALF-P on the proliferation and survival of OCs.
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Affiliation(s)
- Ting Wang
- Division of Hepatology, Department of Internal Medicine, Iwate Medical University, Morioka, Iwate, Japan,
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Hepatitis B virus core protein sensitizes hepatocytes to tumor necrosis factor-induced apoptosis by suppression of the phosphorylation of mitogen-activated protein kinase kinase 7. J Virol 2014; 89:2041-51. [PMID: 25428880 DOI: 10.1128/jvi.03106-14] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Hepatitis B, which caused by hepatitis B virus (HBV) infection, remains a major health threat worldwide. Hepatic injury and regeneration from chronic inflammation are the main driving factors of liver fibrosis and cirrhosis in chronic hepatitis B. Proinflammatory tumor necrosis factor alpha (TNF-α) has been implicated as a major inducer of liver cell death during viral hepatitis. Here, we report that in hepatoma cell lines and in primary mouse and human hepatocytes, expression of hepatitis B virus core (HBc) protein made cells susceptible to TNF-α-induced apoptosis. We found by tandem affinity purification and mass spectrometry that receptor of activated protein kinase C 1 (RACK1) interacted with HBc. RACK1 was recently reported as a scaffold protein that facilitates the phosphorylation of mitogen-activated protein kinase kinase 7 (MKK7) by its upstream activators. Our study showed that HBc abrogated the interaction between MKK7 and RACK1 by competitively binding to RACK1, thereby downregulating TNF-α-induced phosphorylation of MKK7 and the activation of c-Jun N-terminal kinase (JNK). In line with this finding, specific knockdown of MKK7 increased the sensitivity of hepatocytes to TNF-α-induced apoptosis, while overexpression of RACK1 counteracted the proapoptotic activity of HBc. Capsid particle formation was not obligatory for HBc proapoptotic activity, as analyzed using an assembly-defective HBc mutant. In conclusion, the expression of HBc sensitized hepatocytes to TNF-α-induced apoptosis by disrupting the interaction between MKK7 and RACK1. Our study is thus the first indication of the pathogenic effects of HBc in liver injury during hepatitis B. IMPORTANCE Our study revealed a previously unappreciated role of HBc in TNF-α-mediated apoptosis. The proapoptotic activity of HBc is important for understanding hepatitis B pathogenesis. In particular, HBV variants associated with severe hepatitis may upregulate apoptosis of hepatocytes through enhanced HBc expression. Our study also found that MKK7 is centrally involved in TNF-α-induced hepatocyte apoptosis and revealed a multifaceted role for JNK signaling in this process.
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Kim JB, Park SY, Kim HR, Ahn YH, Jee HG, Lee JH, Yu SJ, Lee HS, Lee M, Yoon JH, Kim YJ. JNK signaling in hepatocarcinoma cells is associated with the side population upon treatment with anticancer drugs. Mol Med Rep 2014; 11:263-8. [PMID: 25351906 DOI: 10.3892/mmr.2014.2761] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 05/15/2014] [Indexed: 11/05/2022] Open
Abstract
Liver cancer is one of the most drug-resistant cancer types, and cancer stem cells are related to drug resistance. c-Jun-N-terminal kinase (JNK) signaling is involved in drug resistance, and the side population of cells (SP cells) can be used as a model to study liver cancer stem cells. We sought to evaluate the relationship between SP cells and JNK signaling in hepatocarcinoma cells. For this purpose, we examined cell proliferation and the SP cell ratio following treatment of Huh7 cells with the anticancer drugs 5-fluorouracil (5-FU) and paclitaxel. The expression of phospho-stress-activated protein kinase (SAPK)/JNK in the treated cells was evaluated using immunoblotting. 5-FU and paclitaxel treatment increased the number of SP cells and JNK phosphorylation, and decreased cell survival. Huh7 and HepG2 cells were also treated with SP600125, a JNK inhibitor, to study the relationship between SP cells and JNK signaling. The increase in the number of SP cells and the SAPK/JNK and c-Jun phosphorylation was reverted by SP600125 treatment in these cells. We also used immunohistochemistry and showed that SAPK/JNK and c-Jun phosphorylation are increased in hepatocarcinoma tissues. In conclusion, our results demonstrate that the number of SP cells and SAPK/JNK phosphorylation are increased upon treatment with anticancer drugs, and that this increase is blocked by inhibition of JNK signaling. These findings suggest that drug resistance in liver cancer may involve an increase in the number of SP cells following JNK activation.
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Affiliation(s)
- Jong Bin Kim
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Seo-Young Park
- Biomedical Research Institute, Seoul National University Hospital, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Hye Ri Kim
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Yeon Hwa Ahn
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Hyeon-Gun Jee
- Cancer Research Institute, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Jeong-Hoon Lee
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Su Jong Yu
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Hyo-Suk Lee
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Minjong Lee
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Jung-Hwan Yoon
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Yoon Jun Kim
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Jongno-gu, Seoul 110-799, Republic of Korea
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325
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Zhao E, Amir M, Lin Y, Czaja MJ. Stathmin mediates hepatocyte resistance to death from oxidative stress by down regulating JNK. PLoS One 2014; 9:e109750. [PMID: 25285524 PMCID: PMC4186850 DOI: 10.1371/journal.pone.0109750] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 09/10/2014] [Indexed: 12/11/2022] Open
Abstract
Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK). The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth.
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Affiliation(s)
- Enpeng Zhao
- Department of Medicine and Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Muhammad Amir
- Department of Medicine and Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Yu Lin
- Department of Medicine and Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Mark J. Czaja
- Department of Medicine and Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York, United States of America
- * E-mail:
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326
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LI XIA, HE CAN, WU WANGYANG, HUANG HUAN, LI WEIZU, YIN YANYAN. Anti-fibrotic effects of Acremoniumterricola milleretal mycelium on immunological hepatic fibrosis in rats. Mol Med Rep 2014; 10:3327-33. [DOI: 10.3892/mmr.2014.2604] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 07/23/2014] [Indexed: 11/05/2022] Open
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327
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van Swelm RPL, Kramers C, Masereeuw R, Russel FGM. Application of urine proteomics for biomarker discovery in drug-induced liver injury. Crit Rev Toxicol 2014; 44:823-41. [DOI: 10.3109/10408444.2014.931341] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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328
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García-Ruiz I, Solís-Muñoz P, Fernández-Moreira D, Grau M, Colina F, Muñoz-Yagüe T, Solís-Herruzo JA. High-fat diet decreases activity of the oxidative phosphorylation complexes and causes nonalcoholic steatohepatitis in mice. Dis Model Mech 2014; 7:1287-96. [PMID: 25261569 PMCID: PMC4213732 DOI: 10.1242/dmm.016766] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most frequent histological finding in individuals with abnormal liver-function tests in the Western countries. In previous studies, we have shown that oxidative phosphorylation (OXPHOS) is decreased in individuals with NAFLD, but the cause of this mitochondrial dysfunction remains uncertain. The aims of this study were to determine whether feeding mice a high-fat diet (HFD) induces any change in the activity of OXPHOS, and to investigate the mechanisms involved in the pathogenesis of this defect. To that end, 30 mice were distributed between five groups: control mice fed a standard diet, and mice on a HFD and treated with saline solution, melatonin (an antioxidant), MnTBAP (a superoxide dismutase analog) or uric acid (a scavenger of peroxynitrite) for 28 weeks intraperitoneously. In the liver of these mice, we studied histology, activity and assembly of OXPHOS complexes, levels of subunits of these complexes, gene expression of these subunits, oxidative and nitrosative stress, and oxidative DNA damage. In HFD-fed mice, we found nonalcoholic steatohepatitis, increased gene expression of TNFα, IFNγ, MCP-1, caspase-3, TGFβ1 and collagen α1(I), and increased levels of 3-tyrosine nitrated proteins. The activity and assembly of all OXPHOS complexes was decreased to about 50–60%. The amount of all studied OXPHOS subunits was markedly decreased, particularly the mitochondrial-DNA-encoded subunits. Gene expression of mitochondrial-DNA-encoded subunits was decreased to about 60% of control. There was oxidative damage to mitochondrial DNA but not to genomic DNA. Treatment of HFD-fed mice with melatonin, MnTBAP or uric acid prevented all changes observed in untreated HFD-fed mice. We conclude that a HFD decreased OXPHOS enzymatic activity owing to a decreased amount of fully assembled complexes caused by a reduced synthesis of their subunits. Antioxidants and antiperoxynitrites prevented all of these changes, suggesting that nitro-oxidative stress played a key role in the pathogenesis of these alterations. Treatment with these agents might prevent the development of NAFLD in humans.
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Affiliation(s)
- Inmaculada García-Ruiz
- Research Center, Laboratory of Gastroenterology and Hepatology, University Hospital '12 de Octubre', Complutense University, 28041-Madrid, Spain.
| | - Pablo Solís-Muñoz
- Institute of Liver Studies, King's College Hospital, London, SE5 9RS, UK
| | - Daniel Fernández-Moreira
- Department of Bromatology and Food Hygiene, Military Center of Veterinary of Defense, 28024-Madrid, Spain
| | - Montserrat Grau
- Research Center, Laboratory of Gastroenterology and Hepatology, University Hospital '12 de Octubre', Complutense University, 28041-Madrid, Spain
| | - Francisco Colina
- Department of Pathology, University Hospital '12 de Octubre', Complutense University, 28041-Madrid, Spain
| | - Teresa Muñoz-Yagüe
- Research Center, Laboratory of Gastroenterology and Hepatology, University Hospital '12 de Octubre', Complutense University, 28041-Madrid, Spain
| | - José A Solís-Herruzo
- Research Center, Laboratory of Gastroenterology and Hepatology, University Hospital '12 de Octubre', Complutense University, 28041-Madrid, Spain
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329
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Schattenberg JM, Czaja MJ. Regulation of the effects of CYP2E1-induced oxidative stress by JNK signaling. Redox Biol 2014; 3:7-15. [PMID: 25462060 PMCID: PMC4218941 DOI: 10.1016/j.redox.2014.09.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 09/18/2014] [Accepted: 09/19/2014] [Indexed: 02/07/2023] Open
Abstract
The generation of excessive amounts of reactive oxygen species (ROS) leads to cellular oxidative stress that underlies a variety of forms of hepatocyte injury and death including that from alcohol. Although ROS can induce cell damage through direct effects on cellular macromolecules, the injurious effects of ROS are mediated largely through changes in signal transduction pathways such as the mitogen-activated protein kinase c-Jun N-terminal kinase (JNK). In response to alcohol, hepatocytes have increased levels of the enzyme cytochrome P450 2E1 (CYP2E1) which generates an oxidant stress that promotes the development of alcoholic steatosis and liver injury. These effects are mediated in large part through overactivation of JNK that alters cell death pathways. Targeting the JNK pathway or its downstream effectors may be a useful therapeutic approach to the oxidative stress generated by CYP2E1 in alcoholic liver disease.
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Affiliation(s)
- Jörn M Schattenberg
- I. Department of Medicine, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany
| | - Mark J Czaja
- Department of Medicine and Marion Bessin Liver Research Center, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
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330
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Omega-3 fatty acids reduce obesity-induced tumor progression independent of GPR120 in a mouse model of postmenopausal breast cancer. Oncogene 2014; 34:3504-13. [PMID: 25220417 PMCID: PMC4362785 DOI: 10.1038/onc.2014.283] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 06/27/2014] [Accepted: 07/27/2014] [Indexed: 01/07/2023]
Abstract
Obesity and inflammation are both risk factors for a variety of cancers, including breast cancer in postmenopausal women. Intake of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) decreases the risk of breast cancer, and also reduces obesity-associated inflammation and insulin resistance, but whether the two effects are related is currently unknown. We tested this hypothesis in a postmenopausal breast cancer model using ovariectomized, immune-competent female mice orthotopically injected with Py230 mammary tumor cells. Obesity, whether triggered genetically or by high-fat diet (HFD) feeding, increased inflammation in the mammary fat pad and promoted mammary tumorigenesis. The presence of tumor cells in the mammary fat pad further enhanced the local inflammatory milieu. Tumor necrosis factor-alpha (TNF-α) was the most highly upregulated cytokine in the obese mammary fat pad, and we observed that TNF-α dose-dependently stimulated Py230 cell growth in vitro. An ω-3 PUFA-enriched HFD (referred to as fish oil diet, FOD) reduced inflammation in the obese mammary fat pad in the absence of tumor cells and inhibited Py230 tumor growth in vivo. Although some anti-inflammatory effects of ω-3 PUFAs were previously shown to be mediated by the G-protein-coupled receptor 120 (GPR120), the FOD reduced Py230 tumor burden in GPR120-deficient mice to a similar degree as observed in wild-type mice, indicating that the effect of FOD to reduce tumor growth does not require GPR120 in the host mouse. Instead, in vitro studies demonstrated that ω-3 PUFAs act directly on tumor cells to activate c-Jun N-terminal kinase, inhibit proliferation and induce apoptosis. Our results show that obesity promotes mammary tumor progression in this model of postmenopausal breast cancer and that ω-3 PUFAs, independent of GPR120, inhibit mammary tumor progression in obese mice.
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331
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ZHANG YAN, GU MENGLI, ZHOU XINXIN, MA HAN, YAO HANGPING, JI FENG. Altered expression of ETV1 and its contribution to tumorigenic phenotypes in gastrointestinal stromal tumors. Oncol Rep 2014; 32:927-34. [DOI: 10.3892/or.2014.3281] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 02/24/2014] [Indexed: 11/05/2022] Open
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332
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Reiniers MJ, van Golen RF, van Gulik TM, Heger M. Reactive oxygen and nitrogen species in steatotic hepatocytes: a molecular perspective on the pathophysiology of ischemia-reperfusion injury in the fatty liver. Antioxid Redox Signal 2014; 21:1119-42. [PMID: 24294945 PMCID: PMC4123468 DOI: 10.1089/ars.2013.5486] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 11/14/2013] [Accepted: 12/02/2013] [Indexed: 12/13/2022]
Abstract
SIGNIFICANCE Hepatic ischemia-reperfusion (IR) injury results from the temporary deprivation of hepatic blood supply and is a common side effect of major liver surgery (i.e., transplantation or resection). IR injury, which in most severe cases culminates in acute liver failure, is particularly pronounced in livers that are affected by non-alcoholic fatty liver disease (NAFLD). In NAFLD, fat-laden hepatocytes are damaged by chronic oxidative/nitrosative stress (ONS), a state that is acutely exacerbated during IR, leading to extensive parenchymal damage. RECENT ADVANCES NAFLD triggers ONS via increased (extra)mitochondrial fatty acid oxidation and activation of the unfolded protein response. ONS is associated with widespread protein and lipid (per)oxidation, which reduces the hepatic antioxidative capacity and shifts the intracellular redox status toward an oxidized state. Moreover, activation of the transcription factor peroxisome proliferator-activated receptor α induces expression of mitochondrial uncoupling protein 2, resulting in depletion of cellular energy (ATP) reserves. The reduction in intracellular antioxidants and ATP in fatty livers consequently gives rise to severe ONS and necrotic cell death during IR. CRITICAL ISSUES Despite the fact that ONS mediates both NAFLD and IR injury, the interplay between the two conditions has never been described in detail. An integrative overview of the pathophysiology of NAFLD that renders steatotic hepatocytes more vulnerable to IR injury is therefore presented in the context of ONS. FUTURE DIRECTIONS Effective methods should be devised to alleviate ONS and the consequences thereof in NAFLD before surgery in order to improve resilience of fatty livers to IR injury.
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Affiliation(s)
- Megan J Reiniers
- Department of Surgery, Surgical Laboratory, Academic Medical Center, University of Amsterdam , Amsterdam, The Netherlands
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333
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Bubici C, Papa S. JNK signalling in cancer: in need of new, smarter therapeutic targets. Br J Pharmacol 2014; 171:24-37. [PMID: 24117156 DOI: 10.1111/bph.12432] [Citation(s) in RCA: 262] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 09/09/2013] [Accepted: 09/13/2013] [Indexed: 12/17/2022] Open
Abstract
The JNKs are master protein kinases that regulate many physiological processes, including inflammatory responses, morphogenesis, cell proliferation, differentiation, survival and death. It is increasingly apparent that persistent activation of JNKs is involved in cancer development and progression. Therefore, JNKs represent attractive targets for therapeutic intervention with small molecule kinase inhibitors. However, evidence supportive of a tumour suppressor role for the JNK proteins has also been documented. Recent studies showed that the two major JNK proteins, JNK1 and JNK2, have distinct or even opposing functions in different types of cancer. As such, close consideration of which JNK proteins are beneficial targets and, more importantly, what effect small molecule inhibitors of JNKs have on physiological processes, are essential. A number of ATP-competitive and ATP-non-competitive JNK inhibitors have been developed, but have several limitations such as a lack of specificity and cellular toxicity. In this review, we summarize the accumulating evidence supporting a role for the JNK proteins in the pathogenesis of different solid and haematological malignancies, and discuss many challenges and scientific opportunities in the targeting of JNKs in cancer.
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Affiliation(s)
- Concetta Bubici
- Section of Inflammation and Signal Transduction, Department of Medicine, Imperial College, London, UK; Biosciences Division, School of Health Sciences and Social Care, Brunel University, London, UK
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334
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Sharma G, Dua P, Agarwal SM. A Comprehensive Review of Dysregulated miRNAs Involved in Cervical Cancer. Curr Genomics 2014; 15:310-23. [PMID: 25132800 PMCID: PMC4133953 DOI: 10.2174/1389202915666140528003249] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 05/19/2014] [Accepted: 05/27/2014] [Indexed: 02/06/2023] Open
Abstract
MicroRNAs(miRNAs) have become the center of interest in oncology. In recent years, various studies have demonstrated that miRNAs regulate gene expression by influencing important regulatory genes and thus are responsible for causing cervical cancer. Cervical cancer being the third most diagnosed cancer among the females worldwide, is the fourth leading cause of cancer related mortality. Prophylactic human papillomavirus (HPV) vaccines and new HPV screening tests, combined with traditional Pap test screening have greatly reduced cervical cancer. Yet, thousands of women continue to be diagnosed with and die of this preventable disease annually. This has necessitated the scientists to ponder over ways of evolving new methods and chalk out novel treatment protocols/strategies. As miRNA deregulation plays a key role in malignant transformation of cervical cancer along with its targets that can be exploited for both prognostic and therapeutic strategies, we have collected and reviewed the role of miRNA in cervical cancer. A systematic search was performed using PubMed for articles that report aberrant expression of miRNA in cervical cancer. The present review provides comprehensive information for 246 differentially expressed miRNAs gathered from 51 published articles that have been implicated in cervical cancer progression. Of these, more than 40 miRNAs have been reported in the literature in several instances signifying their role in the regulation of cancer. We also identified 40 experimentally validated targets, studied the cause of miRNAs dysregulation along with its mechanism and role in different stages of cervical cancer. We also identified and analysed miRNA clusters and their expression pattern in cervical cancer. This review is expected to further enhance our understanding in this field and serve as a valuable reference resource.
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Affiliation(s)
- Garima Sharma
- Bioinformatics Division, Institute of Cytology and Preventive Oncology, Noida-201301, India
| | - Pradeep Dua
- Central Council for Research in Ayurvedic Sciences (CCRAS), New Delhi-110058, India
| | - Subhash Mohan Agarwal
- Bioinformatics Division, Institute of Cytology and Preventive Oncology, Noida-201301, India
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335
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Gruben N, Shiri-Sverdlov R, Koonen DPY, Hofker MH. Nonalcoholic fatty liver disease: A main driver of insulin resistance or a dangerous liaison? Biochim Biophys Acta Mol Basis Dis 2014; 1842:2329-2343. [PMID: 25128743 DOI: 10.1016/j.bbadis.2014.08.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 08/02/2014] [Accepted: 08/07/2014] [Indexed: 12/17/2022]
Abstract
Insulin resistance is one of the key components of the metabolic syndrome and it eventually leads to the development of type 2 diabetes, making it one of the biggest medical problems of modern society. Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are tightly associated with insulin resistance. While it is fairly clear that insulin resistance causes hepatic steatosis, it is not known if NAFLD causes insulin resistance. Hepatic inflammation and lipid accumulation are believed to be the main drivers of hepatic insulin resistance in NAFLD. Here we give an overview of the evidence linking hepatic lipid accumulation to the development of insulin resistance, including the accumulation of triacylglycerol and lipid metabolites, such as diacylglycerol and ceramides. In particular, we discuss the role of obesity in this relation by reviewing the current evidence in terms of the reported changes in body weight and/or adipose tissue mass. We further discuss whether the activation or inhibition of inflammatory pathways, Kupffer cells and other immune cells influences the development of insulin resistance. We show that, in contrast to what is commonly believed, neither hepatic steatosis nor hepatic inflammation is sufficient to cause insulin resistance. Many studies show that obesity cannot be ignored as an underlying factor in this relationship and NAFLD is therefore less likely to be one of the main drivers of insulin resistance.
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Affiliation(s)
- Nanda Gruben
- University of Groningen, University Medical Center Groningen, Department of Pediatrics, Molecular Genetics Section, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
| | - Ronit Shiri-Sverdlov
- Maastricht University, Department of Molecular Genetics, PO Box 616, 6200 MD Maastricht, The Netherlands.
| | - Debby P Y Koonen
- University of Groningen, University Medical Center Groningen, Department of Pediatrics, Molecular Genetics Section, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
| | - Marten H Hofker
- University of Groningen, University Medical Center Groningen, Department of Pediatrics, Molecular Genetics Section, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
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Regnault C, Worms IAM, Oger-Desfeux C, MelodeLima C, Veyrenc S, Bayle ML, Combourieu B, Bonin A, Renaud J, Raveton M, Reynaud S. Impaired liver function in Xenopus tropicalis exposed to benzo[a]pyrene: transcriptomic and metabolic evidence. BMC Genomics 2014; 15:666. [PMID: 25103525 PMCID: PMC4141109 DOI: 10.1186/1471-2164-15-666] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 07/30/2014] [Indexed: 12/20/2022] Open
Abstract
Background Despite numerous studies suggesting that amphibians are highly sensitive to cumulative anthropogenic stresses, the role pollutants play in the decline of amphibian populations remains unclear. Amongst the most common aquatic contaminants, polycyclic aromatic hydrocarbons (PAHs) have been shown to induce several adverse effects on amphibian species in the larval stages. Conversely, adults exposed to high concentrations of the ubiquitous PAH, benzo[a]pyrene (BaP), tolerate the compound thanks to their highly efficient hepatic detoxification mechanisms. Due to this apparent lack of toxic effect on adults, no studies have examined in depth the potential toxicological impact of PAH on the physiology of adult amphibian livers. This study sheds light on the hepatic responses of Xenopus tropicalis when exposed to high environmentally relevant concentrations of BaP, by combining a high throughput transcriptomic approach (mRNA deep sequencing) and a characterization of cellular and physiological modifications to the amphibian liver. Results Transcriptomic changes observed in BaP-exposed Xenopus were further characterized using a time-dependent enrichment analysis, which revealed the pollutant-dependent gene regulation of important biochemical pathways, such as cholesterol biosynthesis, insulin signaling, adipocytokines signaling, glycolysis/gluconeogenesis and MAPK signaling. These results were substantiated at the physiological level with the detection of a pronounced metabolic disorder resulting in a possible insulin resistance-like syndrome phenotype. Hepatotoxicity induced by lipid and cholesterol metabolism impairments was clearly identified in BaP-exposed individuals. Conclusions Our data suggested that BaP may disrupt overall liver physiology, and carbohydrate and cholesterol metabolism in particular, even after short-term exposure. These results are further discussed in terms of how this deregulation of liver physiology can lead to general metabolic impairment in amphibians chronically exposed to contaminants, thereby illustrating the role xenobiotics might play in the global decline in amphibian populations. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-666) contains supplementary material, which is available to authorized users.
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337
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Zhang D, Leung PS. Potential roles of GPR120 and its agonists in the management of diabetes. DRUG DESIGN DEVELOPMENT AND THERAPY 2014; 8:1013-27. [PMID: 25114508 PMCID: PMC4122337 DOI: 10.2147/dddt.s53892] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Free fatty acids (FFAs) serve not only as nutrients that provide energy but also as extracellular signaling molecules that manipulate intracellular physiological events through FFA receptors (FFARs) such as FFAR4. FFAR4 is also known as G-protein coupled receptor 120 (GPR120). The main role of GPR120 is to elicit FFA regulation on metabolism homeostasis. GPR120 agonism correlates with prevention of the occurrence and development of metabolic disorders such as obesity and diabetes. GPR120 activation directly or indirectly inhibits inflammation, modulates hormone secretion from the gastrointestinal tract and pancreas, and regulates lipid and/or glucose metabolism in adipose, liver, and muscle tissues, which may help prevent obesity and diabetes. This review summarizes recent advances in physiological roles of GPR120 in preventing insulin resistance and protecting pancreatic islet function, and examines how resident GPR120 in the pancreas may be involved in modulating pancreatic islet function.
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Affiliation(s)
- Dan Zhang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | - Po Sing Leung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
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338
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Yoshida K, Murata M, Yamaguchi T, Matsuzaki K. TGF-β/Smad signaling during hepatic fibro-carcinogenesis (review). Int J Oncol 2014; 45:1363-71. [PMID: 25050845 PMCID: PMC4151811 DOI: 10.3892/ijo.2014.2552] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 06/04/2014] [Indexed: 12/11/2022] Open
Abstract
After hepatitis virus infection, plasma transforming growth factor (TGF)-β increases in either the acute or chronic inflammatory microenvironment. Although TGF-β is upregulated in patients with hepatocellular carcinoma, it is one of the most potent growth inhibitors for hepatocytes. This cytokine also upregulates extracellular matrix (ECM) production of hepatic stellate cells. Therefore, TGF-β is considered to be the major factor regulating liver carcinogenesis and accelerating liver fibrosis. Smad2 and Smad3 act as the intracellular mediators of TGF-β signal transduction pathway. We have generated numerous antibodies against individual phosphorylation sites in Smad2/3, and identified 3 types of phosphorylated forms (phospho-isoforms): COOH-terminally phosphorylated Smad2/3 (pSmad2C and pSmad3C), linker phosphorylated Smad2/3 (pSmad2L and pSmad3L) and dually phosphorylated Smad2/3 (pSmad2L/C and pSmad3L/C). These Smad phospho-isoforms are categorized into 3 groups: cytostatic pSmad3C signaling, mitogenic pSmad3L signaling and invasive/fibrogenic pSmad2L/C signaling. In this review, we describe differential regulation of TGF-β/Smad signaling after acute or chronic liver injuries. In addition, we consider how chronic inflammation associated with hepatitis virus infection promotes hepatic fibrosis and carcinogenesis (fibro-carcinogenesis), focusing on alteration of Smad phospho-isoform signaling. Finally, we show reversibility of Smad phospho-isoform signaling after therapy against hepatitis virus infection.
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Affiliation(s)
- Katsunori Yoshida
- Department of Gastroenterology and Hepatology, Kansai Medical University, Hirakata, Osaka 573-1010, Japan
| | - Miki Murata
- Department of Gastroenterology and Hepatology, Kansai Medical University, Hirakata, Osaka 573-1010, Japan
| | - Takashi Yamaguchi
- Department of Gastroenterology and Hepatology, Kansai Medical University, Hirakata, Osaka 573-1010, Japan
| | - Koichi Matsuzaki
- Department of Gastroenterology and Hepatology, Kansai Medical University, Hirakata, Osaka 573-1010, Japan
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339
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Navasa N, Martín I, Iglesias-Pedraz JM, Beraza N, Atondo E, Izadi H, Ayaz F, Fernández-Álvarez S, Hatle K, Som A, Dienz O, Osborne BA, Martínez-Chantar ML, Rincón M, Anguita J. Regulation of oxidative stress by methylation-controlled J protein controls macrophage responses to inflammatory insults. J Infect Dis 2014; 211:135-45. [PMID: 25028693 DOI: 10.1093/infdis/jiu389] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Mitochondria contribute to macrophage immune function through the generation of reactive oxygen species, a byproduct of the mitochondrial respiratory chain. MCJ (also known as DnaJC15) is a mitochondrial inner membrane protein identified as an endogenous inhibitor of respiratory chain complex I. Here we show that MCJ is essential for the production of tumor necrosis factor by macrophages in response to a variety of Toll-like receptor ligands and bacteria, without affecting their phagocytic activity. Loss of MCJ in macrophages results in increased mitochondrial respiration and elevated basal levels of reactive oxygen species that cause activation of the JNK/c-Jun pathway, lead to the upregulation of the TACE (also known as ADAM17) inhibitor TIMP-3, and lead to the inhibition of tumor necrosis factor shedding from the plasma membrane. Consequently, MCJ-deficient mice are resistant to the development of fulminant liver injury upon lipopolysaccharide administration. Thus, attenuation of the mitochondrial respiratory chain by MCJ in macrophages exquisitely regulates the response of macrophages to infectious insults.
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Affiliation(s)
- Nicolás Navasa
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst Proteomics Unit
| | | | | | | | | | - Hooman Izadi
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst
| | - Furkan Ayaz
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst
| | | | - Ketki Hatle
- Department of Medicine, University of Vermont College of Medicine, Burlington
| | - Abhigyam Som
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst
| | - Oliver Dienz
- Department of Medicine, University of Vermont College of Medicine, Burlington
| | - Barbara A Osborne
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst
| | - Maria Luz Martínez-Chantar
- Metabolomics Unit, CIC bioGUNE Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Technology Park of Bizkaia, Derio Biochemistry and Molecular Biology Department, University of the Basque Country
| | - Mercedes Rincón
- Department of Medicine, University of Vermont College of Medicine, Burlington
| | - Juan Anguita
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst Proteomics Unit Ikerbasque, Basque Foundation for Science, Bilbao, Spain
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340
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Lu Y, Liu X, Jiao Y, Xiong X, Wang E, Wang X, Zhang Z, Zhang H, Pan L, Guan Y, Cai D, Ning G, Li X. Periostin promotes liver steatosis and hypertriglyceridemia through downregulation of PPARα. J Clin Invest 2014; 124:3501-13. [PMID: 25003192 DOI: 10.1172/jci74438] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 05/22/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatosteatosis is characterized by an aberrant accumulation of triglycerides in the liver; however, the factors that drive obesity-induced fatty liver remain largely unknown. Here, we demonstrated that the secreted cell adhesion protein periostin is markedly upregulated in livers of obese rodents and humans. Notably, overexpression of periostin in the livers of WT mice promoted hepatic steatosis and hypertriglyceridemia. Conversely, both genetic ablation of periostin and administration of a periostin-neutralizing antibody dramatically improved hepatosteatosis and hypertriglyceridemia in obese mice. Overexpression of periostin resulted in reduced expression of peroxisome proliferator-activated receptor α (PPARα), a master regulator of fatty acid oxidation, and activation of the JNK signaling pathway. In mouse primary hepatocytes, inhibition of α6β4 integrin prevented activation of JNK and suppression of PPARα in response to periostin. Periostin-dependent activation of JNK resulted in activation of c-Jun, which prevented RORα binding and transactional activation at the Ppara promoter. Together, these results identify a periostin-dependent pathway that mediates obesity-induced hepatosteatosis.
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341
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González-Rodríguez Á, Reibert B, Amann T, Constien R, Rondinone CM, Valverde ÁM. In vivo siRNA delivery of Keap1 modulates death and survival signaling pathways and attenuates concanavalin-A-induced acute liver injury in mice. Dis Model Mech 2014; 7:1093-100. [PMID: 24997191 PMCID: PMC4142729 DOI: 10.1242/dmm.015537] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Oxidative stress contributes to the progression of acute liver failure (ALF). Transcription factor nuclear factor-erythroid 2-related factor (Nrf2) serves as an endogenous regulator by which cells combat oxidative stress. We have investigated liver damage and the balance between death and survival signaling pathways in concanavalin A (ConA)-mediated ALF using in vivo siRNA delivery targeting Keap1 in hepatocytes. For that goal, mice were injected with Keap1- or luciferase-siRNA-containing liposomes via the tail vein. After 48 hours, ALF was induced by ConA. Liver histology, pro-inflammatory mediators, antioxidant responses, cellular death, and stress and survival signaling were assessed. Keap1 mRNA and protein levels significantly decreased in livers of Keap1-siRNA-injected mice. In these animals, histological liver damage was less evident than in control mice when challenged with ConA. Likewise, markers of cellular death (FasL and caspases 8, 3 and 1) decreased at 4 and 8 hours post-injection. Nuclear Nrf2 and its target, hemoxygenase 1 (HO1), were elevated in Keap1-siRNA-injected mice compared with control animals, resulting in reduced oxidative stress in the liver. Similarly, mRNA levels of pro-inflammatory cytokines were reduced in livers from Keap1-siRNA-injected mice. At the molecular level, activation of c-jun (NH2) terminal kinase (JNK) was ameliorated, whereas the insulin-like growth factor I receptor (IGFIR) survival pathway was maintained upon ConA injection in Keap1-siRNA-treated mice. In conclusion, our results have revealed a potential therapeutic use of in vivo siRNA technology targeted to Keap1 to combat oxidative stress by modulating Nrf2-mediated antioxidant responses and IGFIR survival signaling during the progression of ALF.
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Affiliation(s)
- Águeda González-Rodríguez
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Spain Instituto de Investigaciones Biomédicas "Alberto Sols" (Consejo Superior de Investigaciones Científicas/Universidad Autónoma de Madrid), 28029 Madrid, Spain
| | | | | | | | | | - Ángela M Valverde
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Spain
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342
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Zhang Y, Qiu Z, Wei L, Tang R, Lian B, Zhao Y, He X, Xie L. Integrated analysis of mutation data from various sources identifies key genes and signaling pathways in hepatocellular carcinoma. PLoS One 2014; 9:e100854. [PMID: 24988079 PMCID: PMC4079600 DOI: 10.1371/journal.pone.0100854] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 05/28/2014] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Recently, a number of studies have performed genome or exome sequencing of hepatocellular carcinoma (HCC) and identified hundreds or even thousands of mutations in protein-coding genes. However, these studies have only focused on a limited number of candidate genes, and many important mutation resources remain to be explored. PRINCIPAL FINDINGS In this study, we integrated mutation data obtained from various sources and performed pathway and network analysis. We identified 113 pathways that were significantly mutated in HCC samples and found that the mutated genes included in these pathways contained high percentages of known cancer genes, and damaging genes and also demonstrated high conservation scores, indicating their important roles in liver tumorigenesis. Five classes of pathways that were mutated most frequently included (a) proliferation and apoptosis related pathways, (b) tumor microenvironment related pathways, (c) neural signaling related pathways, (d) metabolic related pathways, and (e) circadian related pathways. Network analysis further revealed that the mutated genes with the highest betweenness coefficients, such as the well-known cancer genes TP53, CTNNB1 and recently identified novel mutated genes GNAL and the ADCY family, may play key roles in these significantly mutated pathways. Finally, we highlight several key genes (e.g., RPS6KA3 and PCLO) and pathways (e.g., axon guidance) in which the mutations were associated with clinical features. CONCLUSIONS Our workflow illustrates the increased statistical power of integrating multiple studies of the same subject, which can provide biological insights that would otherwise be masked under individual sample sets. This type of bioinformatics approach is consistent with the necessity of making the best use of the ever increasing data provided in valuable databases, such as TCGA, to enhance the speed of deciphering human cancers.
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Affiliation(s)
- Yuannv Zhang
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhaoping Qiu
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lin Wei
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ruqi Tang
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Baofeng Lian
- Shanghai Center for Bioinformation Technology, Shanghai Academy of Science and Technology, Shanghai, China
| | - Yingjun Zhao
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xianghuo He
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- * E-mail: (XH); (LX)
| | - Lu Xie
- Shanghai Center for Bioinformation Technology, Shanghai Academy of Science and Technology, Shanghai, China
- * E-mail: (XH); (LX)
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343
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Chen CL, Tsukamoto H, Machida K. Oncogenic signaling pathways and origins of tumor-initiating stem-like cells of hepatocellular carcinomas induced by hepatitis C virus, alcohol and/or obesity. Hepatol Int 2014; 8:330-8. [PMID: 26202636 PMCID: PMC10560513 DOI: 10.1007/s12072-014-9545-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 05/13/2014] [Indexed: 12/21/2022]
Abstract
This review article discusses the importance and oncogenic signaling pathways of tumor-initiating cells (TICs) in several etiologies of hepatocellular carcinomas (HCCs) induced by hepatitis C virus (HCV), alcohol, obesity and/or chemicals. Stem cells may be present in cancer tissue, and a hierarchy of cells is formed, as is the case for normal tissue. Tumor formation, growth and propagation are maintained by a small proportion of cells with stem cell-like properties. TICs are present in alcohol-fed HCV transgenic mice, diethylnitrosamine/phenobarbital-treated mice (chemical carcinogenesis) and Spnb2 +/- mice (defective TGF-β signal). Alcohol/obesity-associated endotoxemia induces the stem cell marker Nanog through TLR4 signaling to generate TICs and liver tumors in several HCC models. The oncogenic pathway (such as the STAT3 and TLR4-NANOG pathway) and mechanism of generation of TICs of HCCs associated with HCV, alcohol and obesity are discussed. Understanding the molecular stemness signaling and cellular hierarchy and defining key TIC-specific genes will accelerate the development of novel biomarkers and treatment strategies. This review highlights recent advances in understanding the pathogenesis of liver TICs and discusses unanswered questions about the concept of liver TICs. (This project was supported by NIH grants 1R01AA018857 and P50AA11999).
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Affiliation(s)
- Chia-Lin Chen
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA, 90033, USA
| | - Hidekazu Tsukamoto
- Southern California Research Center for ALPD and Cirrhosis, Los Angeles, CA, USA
- Department of Pathology, University of Southern California, Los Angeles, CA, 90033, USA
| | - Keigo Machida
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, CA, 90033, USA.
- Southern California Research Center for ALPD and Cirrhosis, Los Angeles, CA, USA.
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344
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Zhao G, Hatting M, Nevzorova YA, Peng J, Hu W, Boekschoten MV, Roskams T, Muller M, Gassler N, Liedtke C, Davis RJ, Cubero FJ, Trautwein C. Jnk1 in murine hepatic stellate cells is a crucial mediator of liver fibrogenesis. Gut 2014; 63:1159-72. [PMID: 24037431 DOI: 10.1136/gutjnl-2013-305507] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECTIVE The c-Jun N-terminal kinase-1 (Jnk1) gene has been shown to be involved in liver fibrosis. Here, we aimed to investigate the molecular mechanism and define the cell type involved in mediating the Jnk1-dependent effect on liver fibrogenesis. DESIGN Jnk1(f/f) wildtype (WT), Jnk1(-/-) and Jnk1(Δhepa) (hepatocyte-specific deletion of Jnk1) mice were subjected to (i) bile duct ligation (BDL) and (ii) CCl4-induced liver fibrosis. Additionally, we performed bone marrow transplantations (BMT), isolated primary hepatic stellate cells (HSCs), studied their activation in vitro and investigated human diseased liver samples. RESULTS Phosphorylated Jnk was expressed in myofibroblasts, epithelial and inflammatory cells during the progression of fibrogenesis in humans and mice. In mice, liver transaminases, alkaline phosphatase, bilirubin and liver histology revealed reduced injury in Jnk1(-/-) compared with WT and Jnk1(Δhepa) mice correlating with lower hepatocyte cell death and proliferation. Consequently, parameters of liver fibrosis such as Sirius red staining and collagen IA1 and α-smooth muscle actin expression were downregulated in Jnk1(-/-) compared with WT and Jnk1(Δhepa) livers, 4 weeks after CCl4 or BDL. BMT experiments excluded bone marrow-derived cells from having a major impact on the Jnk1-dependent effect on fibrogenesis, while primary HSCs from Jnk1(-/-) livers showed reduced transdifferentiation and extracellular matrix production. Moreover, Jnk1 ablation caused a reduced lifespan and poor differentiation of HSCs into matrix-producing myofibroblasts. CONCLUSIONS Jnk1 in HSCs, but not in hepatocytes, significantly contribute to liver fibrosis development, identifying Jnk1 in HSCs as a profibrotic kinase and a promising cell-directed target for liver fibrosis.
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Affiliation(s)
- Gang Zhao
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | - Maximilian Hatting
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | - Yulia A Nevzorova
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | - Jin Peng
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | - Wei Hu
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | - Mark V Boekschoten
- Division of Human Nutrition, Nutrition, Metabolism & Genomics Group, Wageningen University, Wageningen, The Netherlands
| | - Tania Roskams
- Department of Morphology and Molecular Pathology, Liver Research Unit, University of Leuven, Leuven, Belgium
| | - Michael Muller
- Division of Human Nutrition, Nutrition, Metabolism & Genomics Group, Wageningen University, Wageningen, The Netherlands
| | - Nikolaus Gassler
- Institute of Pathology, University Hospital RWTH Aachen, Aachen, Germany
| | - Christian Liedtke
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
| | - Roger J Davis
- Howard Hughes Medical Institute and University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | | | - Christian Trautwein
- Department of Internal Medicine III, University Hospital RWTH Aachen, Aachen, Germany
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345
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Hellerbrand C. Molecular targets for antifibrotic therapy in liver disease: using magic bullets for crossfire rather than a one-sided shotgun attack. Gut 2014; 63:1039-41. [PMID: 24131636 DOI: 10.1136/gutjnl-2013-305908] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
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346
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Inokuchi-Shimizu S, Park EJ, Roh YS, Yang L, Zhang B, Song J, Liang S, Pimienta M, Taniguchi K, Wu X, Asahina K, Lagakos W, Mackey MR, Akira S, Ellisman MH, Sears DD, Olefsky JM, Karin M, Brenner DA, Seki E. TAK1-mediated autophagy and fatty acid oxidation prevent hepatosteatosis and tumorigenesis. J Clin Invest 2014; 124:3566-78. [PMID: 24983318 DOI: 10.1172/jci74068] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 05/22/2014] [Indexed: 01/04/2023] Open
Abstract
The MAP kinase kinase kinase TGFβ-activated kinase 1 (TAK1) is activated by TLRs, IL-1, TNF, and TGFβ and in turn activates IKK-NF-κB and JNK, which regulate cell survival, growth, tumorigenesis, and metabolism. TAK1 signaling also upregulates AMPK activity and autophagy. Here, we investigated TAK1-dependent regulation of autophagy, lipid metabolism, and tumorigenesis in the liver. Fasted mice with hepatocyte-specific deletion of Tak1 exhibited severe hepatosteatosis with increased mTORC1 activity and suppression of autophagy compared with their WT counterparts. TAK1-deficient hepatocytes exhibited suppressed AMPK activity and autophagy in response to starvation or metformin treatment; however, ectopic activation of AMPK restored autophagy in these cells. Peroxisome proliferator-activated receptor α (PPARα) target genes and β-oxidation, which regulate hepatic lipid degradation, were also suppressed in hepatocytes lacking TAK1. Due to suppression of autophagy and β-oxidation, a high-fat diet challenge aggravated steatohepatitis in mice with hepatocyte-specific deletion of Tak1. Notably, inhibition of mTORC1 restored autophagy and PPARα target gene expression in TAK1-deficient livers, indicating that TAK1 acts upstream of mTORC1. mTORC1 inhibition also suppressed spontaneous liver fibrosis and hepatocarcinogenesis in animals with hepatocyte-specific deletion of Tak1. These data indicate that TAK1 regulates hepatic lipid metabolism and tumorigenesis via the AMPK/mTORC1 axis, affecting both autophagy and PPARα activity.
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347
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Lan F, Misu H, Chikamoto K, Takayama H, Kikuchi A, Mohri K, Takata N, Hayashi H, Matsuzawa-Nagata N, Takeshita Y, Noda H, Matsumoto Y, Ota T, Nagano T, Nakagen M, Miyamoto KI, Takatsuki K, Seo T, Iwayama K, Tokuyama K, Matsugo S, Tang H, Saito Y, Yamagoe S, Kaneko S, Takamura T. LECT2 functions as a hepatokine that links obesity to skeletal muscle insulin resistance. Diabetes 2014; 63:1649-64. [PMID: 24478397 DOI: 10.2337/db13-0728] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Recent articles have reported an association between fatty liver disease and systemic insulin resistance in humans, but the causal relationship remains unclear. The liver may contribute to muscle insulin resistance by releasing secretory proteins called hepatokines. Here we demonstrate that leukocyte cell-derived chemotaxin 2 (LECT2), an energy-sensing hepatokine, is a link between obesity and skeletal muscle insulin resistance. Circulating LECT2 positively correlated with the severity of both obesity and insulin resistance in humans. LECT2 expression was negatively regulated by starvation-sensing kinase adenosine monophosphate-activated protein kinase in H4IIEC hepatocytes. Genetic deletion of LECT2 in mice increased insulin sensitivity in the skeletal muscle. Treatment with recombinant LECT2 protein impaired insulin signaling via phosphorylation of Jun NH2-terminal kinase in C2C12 myocytes. These results demonstrate the involvement of LECT2 in glucose metabolism and suggest that LECT2 may be a therapeutic target for obesity-associated insulin resistance.
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Affiliation(s)
- Fei Lan
- Department of Disease Control and Homeostasis, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Ishikawa, Japan
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Stremmel W, Staffer S, Wannhoff A, Pathil A, Chamulitrat W. Plasma membrane phospholipase A2 controls hepatocellular fatty acid uptake and is responsive to pharmacological modulation: implications for nonalcoholic steatohepatitis. FASEB J 2014; 28:3159-70. [PMID: 24719358 DOI: 10.1096/fj.14-249763] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Excess hepatic fat accumulation leads to nonalcoholic steatohepatitis (NASH), a serious threat to health for which no effective treatment is available. However, the mechanism responsible for fatty acid uptake by hepatocytes remains unclear. Using the human hepatocyte-derived tumor cell line HepG2, we found that fatty acid influx is mediated by a heterotetrameric plasma membrane protein complex consisting of plasma membrane fatty acid-binding protein, caveolin-1, CD36, and calcium-independent membrane phospholipase A2 (iPLA2β). Blocking iPLA2β with the bile acid-phospholipid conjugate ursodeoxycholate-lysophosphatidylethanolamide (UDCA-LPE) caused the dissociation of the complex, thereby inhibiting fatty acid influx (IC50 47 μM), and suppressed the synthesis of all subunits through a reduction in lysophosphatidylcholine from 8.0 to 3.5 μmol/mg of protein and corresponding depletion of phosphorylated c-Jun N-terminal kinase. These findings were substantiated by an observed 56.5% decrease in fatty acid influx in isolated hepatocytes derived from iPLA2β-knockout mice. Moreover, steatosis and inflammation were abrogated by UDCA-LPE treatment in a cellular model of NASH. Thus, iPLA2β acts as an upstream checkpoint for mechanisms that regulate fatty acid uptake, and its inhibition by UDCA-LPE qualifies this nontoxic compound as a therapeutic candidate for the treatment of NASH.-Stremmel, W., Staffer, S., Wannhoff, A., Pathil, A., Chamulitrat, W. Plasma membrane phospholipase A2 controls hepatocellular fatty acid uptake and is responsive to pharmacological modulation: implications for nonalcoholic steatohepatitis.
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Affiliation(s)
- Wolfgang Stremmel
- Department of Gastroenterology, University Hospital Heidelberg, Heidelberg, Germany
| | - Simone Staffer
- Department of Gastroenterology, University Hospital Heidelberg, Heidelberg, Germany
| | - Andreas Wannhoff
- Department of Gastroenterology, University Hospital Heidelberg, Heidelberg, Germany
| | - Anita Pathil
- Department of Gastroenterology, University Hospital Heidelberg, Heidelberg, Germany
| | - Walee Chamulitrat
- Department of Gastroenterology, University Hospital Heidelberg, Heidelberg, Germany
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349
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Wang YY, Lin SY, Chuang YH, Sheu WHH, Tung KC, Chen CJ. Activation of hepatic inflammatory pathways by catecholamines is associated with hepatic insulin resistance in male ischemic stroke rats. Endocrinology 2014; 155:1235-46. [PMID: 24437486 DOI: 10.1210/en.2013-1593] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Patients who experience acute ischemic stroke may develop hyperglycemia, even in the absence of diabetes. In the current study we determined the effects of acute stroke on hepatic insulin signaling, TNF-α expression, endoplasmic reticulum (ER) stress, the activities of c-Jun N-terminal kinase (JNK), inhibitor κB kinase β (IKK-β), and nuclear factor-κB (NF-κB) pathways. Rats with cerebral ischemia developed higher blood glucose, and insulin levels, and insulin resistance index, as well as hepatic gluconeogenic enzyme expression compared with the sham-treated group. The hepatic TNF-α mRNA and protein levels were elevated in stroke rats in association with increased ER stress, phosphorylation of JNK1/2 and IKK-β proteins, IκB/NF-κB signaling, and phosphorylation of insulin receptor-1 (IRS-1) at serine residue. The basal and insulin-stimulated tyrosine phosphorylation of IRS-1 and AKT proteins was reduced. In addition, acute stroke increased circulating catecholamines in association with hepatic adrenergic signaling activation. After administration of a nonselective β-adrenergic receptor blocker (propranolol) before induction of cerebral ischemic injury, hepatic adrenergic transduction, TNF-α expression, ER stress, and the activation of the JNK1/2, IKK-β, and NF-κB pathways, and serine phosphorylation of IRS-1 were all attenuated. In contrast, the phosphorylated IRS-1 at tyrosine site and AKT levels were partially restored with improved poststroke hyperglycemia and insulin resistance index. These results suggest that acute ischemic stroke can activate proinflammatory pathways in the liver by the catecholamines and is associated with the development of hepatic insulin resistance.
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Affiliation(s)
- Ya-Yu Wang
- Division of Family Medicine (Y.Y.W.), Division of Endocrinology and Metabolism (S.Y. L., Y.H.C., W.H.H.S.), Department of Medical Research (C.J.C.), Taichung Veterans General Hospital, Taichung, Taiwan; and Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan (Y.Y.W., K.C.T.); and School of Medicine, National Yang Ming University, Taipei, Taiwan (Y.Y.W, S.Y.L., W.H.H.S.)
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350
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Increased expression of c-Jun in nonalcoholic fatty liver disease. J Transl Med 2014; 94:394-408. [PMID: 24492282 DOI: 10.1038/labinvest.2014.3] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 12/20/2013] [Accepted: 12/23/2013] [Indexed: 02/06/2023] Open
Abstract
Overnutrition is the major cause of nonalcoholic fatty liver disease (NAFLD) and its advanced form nonalcoholic steatohepatitis (NASH). We aimed to develop and characterize a murine model, which resembles both the pathology and nutritional situation, of NASH patients in Western societies. Mice were fed with a NASH-inducing diet (ND) containing sucrose, cholesterol and fats rich in saturated fatty acids in a composition, which mimics Western food. After 12 weeks, ND-fed mice revealed obesity and impaired glucose tolerance. In the liver, ND-feeding led to marked steatosis, hepatocellular damage, inflammation and beginning fibrosis. Transcriptome-wide gene expression analysis and search for over-represented transcription factor target sites among the differentially expressed genes identified activator protein-1 (AP-1) as the most likely factor to cause the transcriptional changes in ND livers. Combining differentially expressed gene and protein-protein interaction network analysis identified c-Jun as hub in the largest connected deregulated sub-network in ND livers. Accordingly, ND livers revealed c-Jun-phosphorylation and nuclear translocation. Moreover, hepatic c-Jun expression was enhanced in ND-fed mice. Combined tissue microarray technology and immunohistochemical analysis confirmed enhanced hepatic c-Jun levels in NAFLD patients, which correlated with inflammation, and notably, with the degree of hepatic steatosis. In summary, our new mouse model shows important pathological changes also found in human NASH and indicates c-Jun/AP-1 activation as critical regulator of hepatic alterations. Abundance of c-Jun in NAFLD likely facilitates development and progression of NASH.
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