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Ivanov AV, Smirnova OA, Petrushanko IY, Ivanova ON, Karpenko IL, Alekseeva E, Sominskaya I, Makarov AA, Bartosch B, Kochetkov SN, Isaguliants MG. HCV core protein uses multiple mechanisms to induce oxidative stress in human hepatoma Huh7 cells. Viruses 2015; 7:2745-70. [PMID: 26035647 PMCID: PMC4488712 DOI: 10.3390/v7062745] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 05/12/2015] [Accepted: 05/26/2015] [Indexed: 12/13/2022] Open
Abstract
Hepatitis C virus (HCV) infection is accompanied by the induction of oxidative stress, mediated by several virus proteins, the most prominent being the nucleocapsid protein (HCV core). Here, using the truncated forms of HCV core, we have delineated several mechanisms by which it induces the oxidative stress. The N-terminal 36 amino acids of HCV core induced TGF\(\upbeta\)1-dependent expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases 1 and 4, both of which independently contributed to the production of reactive oxygen species (ROS). The same fragment also induced the expression of cyclo-oxygenase 2, which, however, made no input into ROS production. Amino acids 37-191 of HCV core up-regulated the transcription of a ROS generating enzyme cytochrome P450 2E1. Furthermore, the same fragment induced the expression of endoplasmic reticulum oxidoreductin 1\(\upalpha\). The latter triggered efflux of Ca2+ from ER to mitochondria via mitochondrial Ca2+ uniporter, leading to generation of superoxide anions, and possibly also H2O2. Suppression of any of these pathways in cells expressing the full-length core protein led to a partial inhibition of ROS production. Thus, HCV core causes oxidative stress via several independent pathways, each mediated by a distinct region of the protein.
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Affiliation(s)
- Alexander V Ivanov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| | - Olga A Smirnova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| | - Irina Y Petrushanko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| | - Olga N Ivanova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| | - Inna L Karpenko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| | - Ekaterina Alekseeva
- Latvian Biomedical Research and Study Center, Ratsupites 1, Riga LV1067, Latvia.
| | - Irina Sominskaya
- Latvian Biomedical Research and Study Center, Ratsupites 1, Riga LV1067, Latvia.
| | - Alexander A Makarov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| | - Birke Bartosch
- Inserm U1052, Cancer Research Center of Lyon, University of Lyon, 151, Cours A Thomas, 69424 Lyon Cedex, Lyon, France.
- DevWeCan Laboratories of Excellence Network (Labex), Lyon F-69000, France.
| | - Sergey N Kochetkov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia.
| | - Maria G Isaguliants
- Ivanovsky Institute of Virology, Gamaleya str. 16, Moscow 123098, Russia.
- Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Ratsupites 5, Riga LV-1069, Latvia.
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobelsvägen 16, Stockholm 17177, Sweden.
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Khan AJ, Sharma A, Choudhuri G, Parmar D. Induction of blood lymphocyte cytochrome P450 2E1 in early stage alcoholic liver cirrhosis. Alcohol 2011; 45:81-7. [PMID: 20843640 DOI: 10.1016/j.alcohol.2010.08.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 07/30/2010] [Accepted: 08/07/2010] [Indexed: 10/19/2022]
Abstract
To validate the induction of blood lymphocyte cytochrome P450 2E1 (CYP2E1) expression in alcoholic liver cirrhosis and mRNA and protein expression of CYP2E1 in freshly prepared blood lymphocytes of alcoholic liver cirrhotic (ACP), nonalcoholic cirrhotic patients (NACP), alcoholic controls (ACs), and nonalcoholic controls (NACs) were investigated. Registered ACP and NACP patients at Sanjay Gandhi Postgraduate Institute of Medical Science, Lucknow, India along with NACs and ACs were included in the study. Real time polymerase chain reaction, enzyme-linked immunosorbent assay, and CYP2E1-dependent enzyme activity were determined in blood lymphocytes isolated from cases and controls. Significant increases in CYP2E1 mRNA and protein expression were observed in freshly prepared blood lymphocytes isolated from ACs and ACP patients as compared with respective NACs or NACP patients. A concomitant increase in N-nitrosodimethyamine demethylase activity was evident in the blood lymphocytes of ACs and ACP patients. Interestingly, the comparative increase observed in CYP2E1 expression was of greater magnitude in the blood lymphocytes isolated from ACP patients, although they abstained from alcohol drinking. Findings suggest that significant increase in the CYP2E1 mRNA and protein expression in the blood lymphocytes, isolated from early stage ACP patients, can be used to predict alcohol-induced toxicity.
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Wang J, Hu Y, Nekvindova J, Ingelman-Sundberg M, Neve EPA. IL-4-mediated transcriptional regulation of human CYP2E1 by two independent signaling pathways. Biochem Pharmacol 2010; 80:1592-600. [PMID: 20723539 DOI: 10.1016/j.bcp.2010.08.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 08/05/2010] [Accepted: 08/05/2010] [Indexed: 01/21/2023]
Abstract
Cytochrome P450 2E1 (CYP2E1), the alcohol-inducible member of the cytochrome P450 super family, plays an important role in both physiological and pathophysiological processes. The present study focused on the induction of human CYP2E1 transcription by the anti-inflammatory cytokine interleukin-4 (IL-4) in human hepatoma B16A2 cells and revealed that this regulation is mediated by two independent pathways. RNA interference and overexpression of STAT6, indicated that the JAK-STAT signaling pathway is involved in IL-4-dependent induction and mutagenesis revealed the presence of a STAT6 binding site in CYP2E1 proximal promoter region (-583/-574-bp). However, inhibition of the JAK-STAT6 pathway using JAK1 siRNA constructs could only partially inhibit the induction of CYP2E1 promoter constructs indicating the presence of a second IL-4 responsive element. Indeed by using a series of truncated CYP2E1 promoter constructs a second more distal IL-4 responsive element (-1604/-1428-bp) was identified, which was further shown to involve the activation of IRS1/2. This induction was dependent on the transcription factor NFATc1 as IL-4-induced CYP2E1 expression was altered by silencing or overexpressing NFATc1. A NFATc1 binding site was identified in the second distal IL-4 responsive element (-1551/-1545-bp) by chromatin immunoprecipitation (ChIP) analysis. Finally simultaneous siRNA-mediated down-regulation of both STAT6 and NFATc1 or mutation of both STAT6 and NFATc1 binding sites abolished the IL-4-dependent transcriptional induction of CYP2E1, demonstrating that both pathways are required for maximal activation. In conclusion, the present study indicates that the induction of CYP2E1 transcription by IL-4 is mediated through two independent parallel pathways, involving JAK-STAT6 and IRS1/2 and NFATc1.
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Affiliation(s)
- Jue Wang
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institute, Nanna Svartz väg 2, 171 77 Stockholm, Sweden
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Hubich AI, Lakhvich FA, Sholukh MV. The mechanism of the rat liver cytochrome P4502E1 inhibition by the synthetic prostanoids of A-type. Prostaglandins Other Lipid Mediat 2009; 89:16-9. [PMID: 19464662 DOI: 10.1016/j.prostaglandins.2009.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 01/27/2009] [Accepted: 02/20/2009] [Indexed: 11/19/2022]
Abstract
AIM The elucidation of mechanism of A-type synthetic prostanoids inhibitory action on microsomal cytochrome P(450)2E1 (CYP2E1) from rat liver activity was carried out. RESULTS Analogs U-34 and U-26 in a final concentration of 1 x 10(-5)M inhibited CYP2E1 activity by 93% and 46%, respectively; however natural prostaglandins had no effect. These synthetic prostanoids of A-type (5 x 10(-8) to 10(-4)M) inhibited chlorzoxazone hydroxylation in a dose-dependent manner while IC(50)=7.1 x 10(-7)M and 8.0 x 10(-7)M for U-26 and U-34, respectively. The curves of CYP2E1 activity in the presence of different concentrations of chlorzoxazone and varying concentration of prostanoids were hyperbolic. Double-reciprocal plots of these results 1/V=f(1/S) indicated that prostanoids inhibit CYP2E1 through a competitive mechanism with particular effect. CONCLUSION CYP2E1 is a target for A-type prostanoids, possessing 2-oxo-4-amino-oct-3(E)-enyl in alpha- or omega-chain, which are able to inhibit its action through a competitive mechanism.
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Affiliation(s)
- A I Hubich
- Department of Biochemistry, Belarussian State University, Minsk, Belarus.
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Abstract
Chronic hepatitis C infection persists in more than 170 million people worldwide and is one of the major causes of hepatic failure and liver transplantation. Recent studies have demonstrated that hepatitis C virus (HCV)-derived proteins have the capacity to generate substantial oxidative stress within the hepatocyte. Subsequently, oxidative stress has been identified as a significant mechanistic pathway culminating in the development of hepatic cirrhosis, liver failure and liver cancer. In vitro HCV-induced oxidative stress has been demonstrated to activate cellular signaling pathways involved in both inflammatory and fibrogenic responses. In addition, oxidative stress has also been shown to play a role in HCV replication. Preliminary data from small clinical trials have implicated oxidative stress as a risk factor for liver fibrosis and increased HCV viral load. Although conclusive evidence from large-scale clinical trials is lacking, it is possible that antioxidant co-therapies may improve hepatic inflammation, retard fibrosis progression and improve the ability to achieve a sustained viral response with standard antiviral therapy.
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