Lin Deng

Suez Canal University, Al Ismā‘īlīyah, Al Ismā‘īlīyah, Egypt

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Publications (41)110.5 Total impact

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    ABSTRACT: Hepatitis C virus (HCV) induces cytopathic effects in the form of hepatocytes apoptosis thought to be resulted from the interaction between viral proteins and host factors. Using pathway specific PCR array, we identified 9 apoptosis-related genes that are dysregulated during HCV infection, of which the BH3-only pro-apoptotic Bcl-2 family protein, BIK, was consistently up-regulated at the mRNA and protein levels. Depletion of BIK protected host cells from HCV-induced caspase-3/7 activation but not the inhibitory effect of HCV on cell viability. Furthermore, viral RNA replication and release were significantly suppressed in BIK-depleted cells and over-expression of the RNA-dependent RNA polymerase, NS5B, was able to induce BIK expression. Immunofluorescence and co-immunoprecipitation assays showed co-localization and interaction of BIK and NS5B, suggesting that BIK may be interacting with the HCV replication complex through NS5B. These results imply that BIK is essential for HCV replication and that NS5B is able to induce BIK expression.
    Virology. 11/2014;
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    ABSTRACT: The development of complementary and/or alternative drugs for treatment of hepatitis C virus (HCV) infection is still needed. Antiviral compounds in medicinal plants are potentially good targets to study. Morinda citrifolia is a common plant distributed widely in Indo-Pacific region, whose fruits and leaves are among the food sources and also used as a treatment in traditional medicine. In this study, by using the HCV cell culture system, we demonstrated that a methanol extract, its n-hexane and ethyl acetate fractions from M. citrifolia leaves possessed anti-HCV activities with 50%-inhibitory concentration (IC50 ) of 20.6, 6.1 and 6.6 µg/ml, respectively. Bioactivity-guided purification and structural analysis led to isolation and identification of pheophorbide a, the major catabolite of chlorophyll a, as an anti-HCV compound present in the extracts (IC50 = 0.3 µg/ml). We also found that pyropheophorbide a possessed anti-HCV activity (IC50 = 0.2 µg/ml). The 50%-cytotoxic concentrations (CC50 ) of pheophorbide a and pyropheophorbide a were 10.0 and 7.2 µg/ml, respectively, with selectivity index being 33 and 36, respectively. On the other hand, chlorophyll a, sodium copper chlorophyllin and pheophytin a barely, or only marginally, exhibited anti-HCV activities. Time-of-addition analysis revealed that pheophorbide a and pyropheophorbide a act at both the entry and the post-entry steps. The present results suggest that pheophorbide a and its related compounds would be good candidates for seed compounds to develop antivirals against HCV.
    Microbiology and Immunology 01/2014; · 1.55 Impact Factor
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    ABSTRACT: Development of complementary and/or alternative drugs for treatment of hepatitis C virus (HCV) infection is still much needed from clinical and economical points of view. Antiviral substances obtained from medicinal plants are potentially good targets to study. Glycyrrhiza uralensis and G. glabra have been commonly used in both traditional and modern medicine. In this study, we examined extracts of G. uralensis roots and their components for anti-HCV activities using the HCV cell culture system. Our results revealed that a methanol extract of G. uralensis roots and its chloroform fraction possessed anti-HCV activities with 50%-inhibitory concentrations (IC50 ) of 20.0 and 8.0 μg/ml, respectively. Through bioactivity-guided purification and structural analysis, we isolated and identified glycycoumarin, glycyrin, glycyrol and liquiritigenin as anti-HCV compounds, with IC50 being 8.8, 7.2, 4.6 and 16.4 μg/ml, respectively. On the other hand, glycyrrhizin, the most common constituent in G. uralensis, and its monoammonium salt showed only marginal levels of anti-HCV activity. We also found that licochalcone A and glabridin, known as the exclusive constituents of G. inflata and G. glabra, respectively, possessed anti-HCV activities, with IC50 being 2.5 and 6.2 μg/ml, respectively. Another chalcone, isoliquiritigenin, also showed anti-HCV activity, with IC50 of 3.7 μg/ml. Time-of-addition analysis revealed that all the Glycyrrhiza-derived anti-HCV compounds tested in this study act at the post-entry step. In conclusion, our present results suggest that glycycoumarin, glycyrin, glycyrol and liquiritigenin isolated from G. uralensis as well as isoliquiritigenin, licochalcone A and glabridin would be good candidates for seed compounds to develop antivirals against HCV.
    Microbiology and Immunology 01/2014; · 1.55 Impact Factor
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    ABSTRACT: Effective therapeutic vaccines against virus infection must induce sufficient levels of cell-mediated immune responses against the target viral epitopes and also must avoid concomitant risk factors, such as potential carcinogenic properties. The nonstructural protein 3 (NS3) of hepatitis C virus (HCV) carries a variety of CD4+ and CD8+ T cell epitopes, and induces strong HCV-specific T cell responses, which are correlated with viral clearance and resolution of acute HCV infection. On the other hand, NS3 possesses serine protease and nucleoside triphosphatase (NTPase)/RNA helicase activities, which not only play important roles in viral life cycle but also concomitantly interfere with host defense mechanisms by deregulating normal cellular functions. In this study, we constructed a series of DNA vaccines that express NS3 of HCV. To avoid the potential harm of NS3, we introduced mutations to the catalytic triad of the serine protease (H57A, D81A and S139A) and the NTPase/RNA helicase domain (K210N, F444A, R461Q and W501A) to eliminate the enzymatic activities. Immunization of BALB/c mice with each of the DNA vaccine candidates (pNS3[S139A/K210N], pNS3[S139A/F444A], pNS3[S139A/R461Q] and pNS3[S139A/W501A]) that expresses an NS3 mutant lacking both serine protease and NTPase/helicase activities induced T cell immune responses to the degree comparable to that induced by the wild type NS3 and the NS3/4A complex, as demonstrated by interferon-γ production and cytotoxic T lymphocytes activities against NS3. The present study has demonstrated that plasmids expressing NS3 mutants, NS3(S139A/K210N), NS3(S139A/F444A), NS3(S139A/R461Q) and NS3(S139A/W501A), which lack both serine protease and NTPase/RNA helicase activities, would be good candidates for safe and efficient therapeutic DNA vaccines against HCV infection.
    PLoS ONE 01/2014; 9(6):e98877. · 3.53 Impact Factor
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    ABSTRACT: Hepatitis C virus (HCV) is a major cause of liver disease and a potential cause of substantial morbidity and mortality worldwide. The overall prevalence of HCV infection is 2%, representing 120 million people worldwide. Current standard treatment using pegylated interferon and ribavirin is effective in only 50% of the patients infected with HCV genotype 1, and is associated with significant side effects. Therefore, it is still of importance to develop new drugs for treatment of HCV. Antiviral substances obtained from natural products, including medicinal plants, are potentially good targets to study. In this study, we evaluated Indonesian medicinal plants for their anti-HCV activities. Ethanol extracts of 21 samples derived from 17 species of medicinal plants explored in the East Java region were tested. Anti-HCV activities were determined by a cell culture method using Huh7.5 cells and HCV strains of 9 different genotypes (1a to 7a, 1b and 2b). Four of the 21 samples tested showed antiviral activities against HCV: Toona sureni leaves (TSL) with 50% inhibitory concentrations (IC50) of 13.9 and 2.0 mug/ml against the HCV J6/JFH1-P47 and -P1 strains, respectively, Melicope latifolia leaves (MLL) with IC50 of 3.5 and 2.1 mug/ml, respectively, Melanolepis multiglandulosa stem (MMS) with IC50 of 17.1 and 6.2 mug/ml, respectively, and Ficus fistulosa leaves (FFL) with IC50 of 15.0 and 5.7 mug/ml, respectively. Time-of-addition experiments revealed that TSL and MLL inhibited both at the entry and post-entry steps while MMS and FFL principally at the entry step. TSL and MLL inhibited all of 11 HCV strains of all the genotypes tested to the same extent. On the other hand, FFL showed significantly weaker inhibitory activities against the HCV genotype 1a strain, and MMS against the HCV strains of genotypes 2b and 7a to a lesser extent, compared to the other HCV genotypes. Ethanol extracts of TSL, MLL, MMS and FFL showed antiviral activities against all the HCV genotypes tested with the exception that some genotype(s) showed significant resistance to FFL and to MMS to a lesser extent. These plant extracts may be good candidates for the development of anti-HCV drugs.
    Virology Journal 08/2013; 10(1):259. · 2.09 Impact Factor
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    ABSTRACT: Background: Hepatitis C virus (HCV) is a major cause of liver disease and a potential cause of substantial morbidity and mortality worldwide. The overall prevalence of HCV infection is 2%, representing 120 million people worldwide. Current standard treatment using pegylated interferon and ribavirin is effective in only 50% of the patients infected with HCV genotype 1, and is associated with significant side effects. Therefore, it is still of importance to develop new drugs for treatment of HCV. Antiviral substances obtained from natural products, including medicinal plants, are potentially good targets to study. In this study, we evaluated Indonesian medicinal plants for their anti-HCV activities. Methods: Ethanol extracts of 21 samples derived from 17 species of medicinal plants explored in the East Java region were tested. Anti-HCV activities were determined by a cell culture method using Huh7.5 cells and HCV strains of 9 different genotypes (1a to 7a, 1b and 2b). Results: Four of the 21 samples tested showed antiviral activities against HCV: Toona sureni leaves (TSL) with 50% inhibitory concentrations (IC 50) of 13.9 and 2.0 μg/ml against the HCV J6/JFH1-P47 and -P1 strains, respectively, Melicope latifolia leaves (MLL) with IC 50 of 3.5 and 2.1 μg/ml, respectively, Melanolepis multiglandulosa stem (MMS) with IC 50 of 17.1 and 6.2 μg/ml, respectively, and Ficus fistulosa leaves (FFL) with IC 50 of 15.0 and 5.7 μg/ml, respectively. Time-of-addition experiments revealed that TSL and MLL inhibited both at the entry and post-entry steps while MMS and FFL principally at the entry step. TSL and MLL inhibited all of 11 HCV strains of all the genotypes tested to the same extent. On the other hand, FFL showed significantly weaker inhibitory activities against the HCV genotype 1a strain, and MMS against the HCV strains of genotypes 2b and 7a to a lesser extent, compared to the other HCV genotypes. Conclusions: Ethanol extracts of TSL, MLL, MMS and FFL showed antiviral activities against all the HCV genotypes tested with the exception that some genotype(s) showed significant resistance to FFL and to MMS to a lesser extent. These plant extracts may be good candidates for the development of anti-HCV drugs.
    Virology Journal. 08/2013; 10(259).
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    ABSTRACT: Hepatocellular carcinoma (HCC) is one of the common sequels of hepatitis C virus (HCV) infection. It remains controversial, however, whether HCV itself plays a direct role in the development of HCC. Although HCV core, NS3 and NS5A proteins were reported to display tumorigenic activities in cell culture and experimental animal systems, their clinical impact on HCC development in humans is still unclear. In this study, we investigated sequence polymorphisms in the core protein, NS3 and NS5A of HCV genotype 1b (HCV-1b) in 49 patients who later developed HCC during a follow-up of an average of 6.5 years and in 100 patients who did not develop HCC after 15-year follow-up. Sequence analysis revealed that Gln at position (70) of the core protein (core-Gln(70) ), Tyr at position (1082) plus Gln at (1112) of NS3 (NS3-Tyr  1082/Gln  111247) and 6 or more mutations in the interferon/ribavirin resistance-determining region of NS5A (NS5A-IRRDR≥6) were significantly associated with development of HCC. Multivariate analysis identified core-Gln(70) , NS3-Tyr(1082) /Gln(1112) 50 and α-fetoprotein (AFP) levels (>20 ng/L) as independent factors associated with HCC. Kaplan-Meier analysis revealed higher cumulative incidence of HCC for patients infected with HCV isolates with core-Gln(70) , NS3-Tyr(1082) /Gln(1112) 52 or both than for those with Non-(Gln(70) plus NS3-Tyr(1082) /Gln(1112) 53 ). In most cases, neither the residues at position 70 of the core protein nor positions (1082) and (1112) of the NS3 protein changed during the observation period. Conclusion, the present results suggest that HCV isolates with core-Gln(70) and/or NS3-Tyr(1082) /Gln(1112) 56 are more closely associated with HCC development compared to those with Non-(Gln(70) plus NS3-Tyr(1082) /Gln(1112) 57 ). (HEPATOLOGY 2012.).
    Hepatology 12/2012; · 12.00 Impact Factor
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    ABSTRACT: Hepatitis C virus (HCV) infection causes not only intrahepatic diseases but also extrahepatic manifestations, including type 2 diabetes. We previously reported that HCV replication suppresses cellular glucose uptake by down-regulation of cell surface expression of glucose transporter 2 (GLUT2) (J Hepatol. 2009, 50: 883-94). GLUT2 mRNA levels were decreased in both HCV RNA replicon cells and HCV J6/JFH1-infected cells. To elucidate molecular mechanisms of HCV-induced suppression of GLUT2 gene expression, we analyzed transcriptional regulation of GLUT2 promoter using a series of GLUT2 promoter-luciferase reporter plasmids. HCV-induced suppression of GLUT2 promoter activity was abrogated when hepatocyte nuclear factor 1α (HNF-1α)-binding motif was deleted from the GLUT2 promoter. HNF-1α mRNA levels were significantly reduced in HCV J6/JFH1-infected cells. Furthermore, HCV infection remarkably decreased the HNF-1α protein levels. We assessed the effects of proteasome inhibitor or lysosomal protease inhibitors on the HCV-induced reduction of HNF-1α protein levels. Treatment of the HCV-infected cells with a lysosomal protease inhibitor, but not with a proteasome inhibitor, restored HNF-1α protein levels, suggesting that HCV infection promotes lysosomal degradation of HNF-1α protein. Overexpression of NS5A protein enhanced lysosomal degradation of HNF-1α protein and suppressed GLUT2 promoter activity. Immunoprecipitation analyses revealed that the domain I of the NS5A protein physically interacts with HNF-1α protein. Taken together, our results suggest that HCV infection suppresses GLUT2 gene expression via down-regulation of HNF-1α expression at transcriptional and posttranslational levels. HCV-induced down-regulation of HNF-1α expression may play a crucial role in glucose metabolic disorders caused by HCV.
    Journal of Virology 09/2012; · 5.08 Impact Factor
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    ABSTRACT: Hepatitis C virus genotype 4 (HCV-4) is the cause of approximately 20% of the 180 million cases of chronic hepatitis C in the world. HCV-4 infection is common in the Middle East and Africa, with an extraordinary high prevalence in Egypt. Viral genetic polymorphisms, especially within core and NS5A regions, have been implicated to influence the response to pegylated-interferon and ribavirin (PEG-IFN/RBV) combination therapy in HCV-1 infection. However, it has not been confirmed in HCV-4 infection. Here, we investigated the impact of heterogeneity of NS5A and core proteins of HCV-4, mostly the subtype HCV-4a, on clinical outcome of 43 Egyptian patients treated with PEG-IFN/RBV. Sliding window analysis over carboxy-terminus of NS5A protein identified the IFN/RBV resistance-determining region (IRRDR) as the most prominent region associated with sustained virological response (SVR). Indeed, 21 (84%) of 25 patients with SVR, but only 5 (28%) of 18 patients with non-SVR, were infected with HCV having IRRDR with 4 or more mutations (IRRDR≥4) (P=0.0004). Multivariate analysis identified IRRDR≥4 as an independent SVR predictor. The positive predictive value of IRRDR≥4 for SVR was 81% (21/26; P=0.002) while its negative predictive value for non-SVR was 76% (13/17; P=0.02). On the other hand, there was no significant correlation between core protein polymorphisms, either at residues 70 or 91, and treatment outcome. In conclusion, the present results demonstrate for the first time that IRRDR≥4, a viral genetic heterogeneity, would be a useful predictive marker for SVR in HCV-4 infection when treated with PEG-IFN/RBV.
    Journal of clinical microbiology 09/2012; · 4.16 Impact Factor
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    ABSTRACT: This study explores pretreatment predictive factors for ultimate virological responses to pegylated interferon-α (1.5 μg/kg/week) and ribavirin (600-1000 mg/day) (PEG-IFN/RBV) combination therapy for patients infected with hepatitis C virus (HCV)-1b and a high viral load. A total of 75 patients underwent PEG-IFN/RBV combination therapy for 48 weeks. HCV amino acid (aa) substitutions in non-structural protein 5a, including those in the IFN/RBV resistance-determining region (IRRDR) and the IFN sensitivity-determining region and the core regions, as well as the genetic variation (rs8099917) near the interleukin 28B (IL28B) gene (genotype TT) were analyzed. Of the 75 patients, 49 % (37/75) achieved a sustained virological response (SVR), 27 % (20/75) showed relapse, and 24 % (18/75) showed null virological response (NVR). Multivariate logistic regression analysis identified IRRDR with 6 or more mutations (IRRDR ≥6) [odds ratio (OR) 11.906, p < 0.0001] and age <60 years (OR 0.228, p = 0.015) as significant determiners of SVR and IL28B minor (OR 14.618, p = 0.0019) and platelets <15 × 10(4)/mm(3) (OR 0.113, p = 0.0096) as significant determiners of NVR. A combination of IRRDR ≥6 and age <60 years improved SVR predictability (93.3 %), and that of IRRDR ≤5 and age ≥60 years improved non-SVR predictability (84.0 %). Similarly, a combination of IL28B minor and platelets <15 × 10(4)/mm(3) improved NVR predictability (85.7 %), and that of IL28B major and platelets ≥15 × 10(4)/mm(3) improved non-NVR (response) (97.1 %) predictability. IRRDR ≥6 and age <60 years were significantly associated with SVR. IL28B minor and platelets <15 × 10(4)/mm(3) were significantly associated with NVR. Certain combinations of these factors improved SVR and NVR predictability and could, therefore, be used to design therapeutic strategies.
    Journal of Gastroenterology 03/2012; 47(10):1143-51. · 3.79 Impact Factor
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    ABSTRACT: The molecular basis of antibody neutralization against hepatitis C virus (HCV) is poorly understood. The E2 glycoprotein of HCV is critically involved in viral infectivity through specific binding to the principal virus receptor component CD81, and is targeted by anti-HCV neutralizing antibodies. A previous study showed that a mutation at position 534 (N534H) within the sixth N-glycosylation motif of E2 of the J6/JFH1 strain of HCV genotype 2a (HCV-2a) was responsible for more efficient access of E2 to CD81 so that the mutant virus could infect the target cells more efficiently. The purpose of this study was to analyze the sensitivity of the parental J6/JFH1, its cell culture-adapted variant P-47 possessing 10 amino acid mutations and recombinant viruses with the adaptive mutations to neutralization by anti-HCV antibodies in sera of HCV-infected patients. The J6/JFH1 virus was neutralized by antibodies in sera of patients infected with HCV-2a and -1b, with mean 50% neutralization titers being 1:670 and 1:200, respectively (P < 0.00001). On the other hand, the P-47 variant showed 50- to 200-times higher sensitivity to antibody neutralization than the parental J6/JFH1 without genotype specificity. The N534H mutation, and another one at position 416 (T416A) near the first N-glycosylation motif to a lesser extent, were shown to be responsible for the enhanced sensitivity to antibody neutralization. The present results suggest that the residues 534, and 416 to a lesser extent, of the E2 glycoprotein are critically involved in the HCV infectivity and antibody neutralization.
    Journal of Medical Virology 02/2012; 84(2):229-34. · 2.37 Impact Factor
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    ABSTRACT: Pegylated-interferon plus ribavirin (PEG-IFN/RBV) therapy is a current standard treatment for chronic hepatitis C. We previously reported that the viral sequence heterogeneity of part of NS5A, referred to as the IFN/RBV resistance-determining region (IRRDR), and a mutation at position 70 of the core protein of hepatitis C virus genotype 1b (HCV-1b) are significantly correlated with the outcome of PEG-IFN/RBV treatment. Here, we aimed to investigate the impact of viral genetic variations within the NS5A and core regions of other genotypes, HCV-2a and HCV-2b, on PEG-IFN/RBV treatment outcome. Pretreatment sequences of NS5A and core regions were analyzed in 112 patients infected with HCV-2a or HCV-2b, who were treated with PEG-IFN/RBV for 24 weeks and followed up for another 24 weeks. The results demonstrated that HCV-2a isolates with 4 or more mutations in IRRDR (IRRDR[2a]≥4) was significantly associated with rapid virological response at week 4 (RVR) and sustained virological response (SVR). Also, another region of NS5A that corresponds to part of the IFN sensitivity-determining region (ISDR) plus its carboxy-flanking region, which we referred to as ISDR/+C[2a], was significantly associated with SVR in patients infected with HCV-2a. Multivariate analysis revealed that IRRDR[2a]≥4 was the only independent predictive factor for SVR. As for HCV-2b infection, an N-terminal half of IRRDR having two or more mutations (IRRDR[2b]/N≥2) was significantly associated with RVR, but not with SVR. No significant correlation was observed between core protein polymorphism and PEG-IFN/RBV treatment outcome in HCV-2a or HCV-2b infection. CONCLUSION: The present results suggest that sequence heterogeneity of NS5A of HCV-2a (IRRDR[2a]≥4 and ISDR/+C[2a]), and that of HCV-2b (IRRDR[2b]/N≥2) to a lesser extent, is involved in determining the viral sensitivity to PEG-IFN/RBV therapy.
    PLoS ONE 01/2012; 7(2):e30513. · 3.53 Impact Factor
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    ABSTRACT: Hepatitis C virus (HCV) infects B lymphocytes and induces mixed cryoglobulinemia and B cell non-Hodgkin's lymphoma. The molecular mechanism for the pathogenesis of HCV infection-mediated B cell disorders remains obscure. To identify the possible role for HCV nonstructural 5A (NS5A) protein in B cells, we generated the stable B cell lines expressing Myc-His tagged NS5A. Immunoprecipitation study in the presence or absence of pervanadate (PV) implied that NS5A was tyrosine phosphorylated by pervanadate (PV) treatment of the cells. Therefore we examined pull-down assay by using glutathione S-transferase (GST)-fusion proteins of various Src homology 2 (SH2) domains, which associates with phosphotyrosine within a specific amino acid sequence. The results showed that NS5A specifically bound to SH2 domain of Fyn from PV-treated B cells in addition to Src homology 3 (SH3) domain. Substitution of Arg(176) to Lys in the SH2 domain of Fyn abrogated this interaction. Deletion mutational analysis demonstrated that N-terminal region of NS5A was not required for the interaction with the SH2 domain of Fyn. Tyr(334) was identified as a tyrosine phosphorylation site in NS5A. Far-western analysis revealed that SH2 domain of Fyn directly bound to NS5A. Fyn and NS5A were colocalized in the lipid raft. These results suggest that NS5A directly binds to the SH2 domain of Fyn in a tyrosine phosphorylation-dependent manner. Lastly, we showed that the expression of NS5A in B cells increased phosphorylation of activation loop tyrosine in the kinase domain of Fyn. NS5A containing ligand for both SH2 and SH3 domains enhances an aberrant autophosphorylation and kinase activity of Fyn in B cells.
    PLoS ONE 01/2012; 7(10):e46634. · 3.53 Impact Factor
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    ABSTRACT: The lack of a culture system that efficiently produces progeny virus has hampered hepatitis C virus (HCV) research. Recently, the discovery of a novel HCV isolate JFH1 and its chimeric derivative J6/JFH1 has led to the development of an efficient virus productive culture system. To construct an easy monitoring system for the viral life cycle of HCV, we generated bicistronic luciferase reporter virus genomes based on the JFH1 and J6/JFH1 isolates, respectively. Transfection of the J6/JFH1-based reporter genome to Huh7.5 cells produced significantly greater levels of progeny virus than transfection of the JFH1 genome. Furthermore, the expression of dominant-negative Vps4, a key molecule of the endosomal sorting complex required for transport machinery, inhibited the virus production of JFH1, but not that of J6/JFH1. These results may account for the different abilities to produce progeny virus between JFH1 and J6/JFH1. Using the J6/JFH1/Luc system, we showed that the two polyanions heparin and polyvinyl sulfate decreased the infectivity of J6/JFH1/Luc virus in a dose-dependent manner. We also analyzed the function of microRNA on HCV replication and found that miR-34b could affect the replication of HCV. The reporter virus generated in this study will be useful for investigating the nature of the HCV life cycle and for identification of HCV inhibitors.
    Microbes and Infection 08/2011; 14(1):69-78. · 2.92 Impact Factor
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    ABSTRACT: Chronic hepatitis C virus (HCV) infection is often associated with type 2 diabetes. However, the precise mechanism underlying this association is still unclear. Here, using Huh-7.5 cells either harboring HCV-1b RNA replicons or infected with HCV-2a, we showed that HCV transcriptionally upregulated the genes for phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G6Pase), the rate-limiting enzymes for hepatic gluconeogenesis. In this way, HCV enhanced the cellular production of glucose 6-phosphate (G6P) and glucose. PEPCK and G6Pase gene expressions are controlled by the transcription factor forkhead box O1 (FoxO1). We observed that although neither the mRNA levels nor the protein levels of FoxO1 expression were affected by HCV, the level of phosphorylation of FoxO1 at Ser319 was markedly diminished in HCV-infected cells compared to the control cells, resulting in an increased nuclear accumulation of FoxO1, which is essential for sustaining its transcriptional activity. It was unlikely that the decreased level of FoxO1 phosphorylation was mediated through Akt inactivation, as we observed an increased phosphorylation of Akt at Ser473 in HCV-infected cells compared to control cells. By using specific inhibitors of c-Jun N-terminal kinase (JNK) and reactive oxygen species (ROS), we demonstrated that HCV infection induced JNK activation via increased mitochondrial ROS production, resulting in decreased FoxO1 phosphorylation, FoxO1 nuclear accumulation, and, eventually, increased glucose production. We also found that HCV NS5A mediated increased ROS production and JNK activation, which is directly linked with the FoxO1-dependent increased gluconeogenesis. Taken together, these observations suggest that HCV promotes hepatic gluconeogenesis through an NS5A-mediated, FoxO1-dependent pathway.
    Journal of Virology 06/2011; 85(17):8556-68. · 5.08 Impact Factor
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    ABSTRACT: Both host and viral factors have been implicated in influencing the response to pegylated-interferon/ribavirin (PEG-IFN/RBV) therapy for hepatitis C virus (HCV) infection. Among the viral factors, sequence heterogeneity within NS5A and core regions has been proposed. This study aimed to clarify the relationship between virological responses to PEG-IFN/RBV therapy and sequence heterogeneity within NS5A, including the IFN/RBV resistance-determining region (IRRDR), the interferon sensitivity-determining region (ISDR) and the core region. Pretreatment sequences of NS5A and the core regions were analyzed in 57 HCV-1b-infected patients who were to be treated with PEG-IFN/RBV. Of 40 patients infected with HCV having an IRRDR with four or more mutations (IRRDR ≥ 4), 28 (70%) patients achieved a sustained virological response (SVR). On the other hand, only 4 (24%) of 17 patients infected with HCV having an IRRDR with three or fewer mutations (IRRDR ≤ 3) achieved a SVR (P = 0.001). Similarly, 22 (71%) of 31 patients infected with HCV and having an ISDR with one or more mutations (ISDR ≥ 1) achieved a SVR while 10 (38%) of 26 patients infected with HCV and having an ISDR without any mutations (ISDR = 0) achieved a SVR (P = 0.014). As for the core region, there was significant correlation between a single mutation at position 70 (Gln(70) ) and non-SVR (P = 0.02). Notably, Gln(70) was more prominently associated with the null response (P = 0.0007). In conclusion, sequence heterogeneity within the IRRDR and ISDR, and a single point mutation at position 70 of the core region of HCV-1b are likely to be correlated with virological responses to PEG-IFN/RBV therapy.
    Microbiology and Immunology 03/2011; 55(6):418-26. · 1.55 Impact Factor
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    ABSTRACT: Objective: Hepatitis C virus (HCV genome) polymorphisms are thought to influence the outcome of pegylated-interferon/ribavirin (PEG-IFN/RBV) therapy. This study aimed to examine non-structural protein 5A (NS5A) polymorphisms, e.g. IFN/RBV resistance-determining region (IRRDR) and IFN sensitivity-determining region (ISDR), and core protein polymorphism as predictive therapeutic markers. Pretreatment sequences of NS5A and core regions were analyzed in 68 HCV-1b-infected patients treated with PEG-IFN/RBV. Of 24 patients infected withHCV having an IRRDR with 6 or more mutations (IRRDR≥6), 18 (75%) patients achieved sustained virological response (SVR), whereas only 11 (25%) of 44 patients infected with HCV having IRRDR≤5 did. IRRDR≥6 was significantly associated with SVR (p < 0.0001). On the other hand, ISDR≥2 was significantly associated with relapse (either before [breakthrough] or after end-of-treatment response [ETR[-]relapse]) (p < 0.05) and a point mutation of the core protein from Arg to Gln at position 70 (Gln(70)) was significantly associated with null-response (p < 0.05). Multivariate analysis identified IRRDR≥6 as the only viral genetic factor that independently predicted SVR. NS5A (IRRDR and ISDR) and core protein polymorphisms are associated with the outcome of PEG-IFN/RBV therapy for chronic hepatitis C. In particular, IRRDR≥6 is a useful marker for prediction of SVR.
    Intervirology 02/2011; 55(1):1-11. · 1.89 Impact Factor
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    Ikuo Shoji, Lin Deng, Hak Hotta
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    ABSTRACT: Hepatitis C virus (HCV) infection causes not only intrahepatic diseases but also extrahepatic manifestations, including metabolic disorders. Chronic HCV infection is often associated with type 2 diabetes. However, the precise mechanism underlying this association is still unclear. Glucose is transported into hepatocytes via glucose transporter 2 (GLUT2). Hepatocytes play a crucial role in maintaining plasma glucose homeostasis via the gluconeogenic and glycolytic pathways. We have been investigating the molecular mechanism of HCV-related type 2 diabetes using HCV RNA replicon cells and HCV J6/JFH1 system. We found that HCV replication down-regulates cell surface expression of GLUT2 at the transcriptional level. We also found that HCV infection promotes hepatic gluconeogenesis in HCV J6/JFH1-infected Huh-7.5 cells. HCV infection transcriptionally up-regulated the genes for phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G6Pase), the rate-limiting enzymes for hepatic gluconeogenesis. Gene expression of PEPCK and G6Pase was regulated by the transcription factor forkhead box O1 (FoxO1) in HCV-infected cells. Phosphorylation of FoxO1 at Ser319 was markedly diminished in HCV-infected cells, resulting in increased nuclear accumulation of FoxO1. HCV NS5A protein was directly linked with the FoxO1-dependent increased gluconeogenesis. This paper will discuss the current model of HCV-induced glucose metabolic disorders.
    Frontiers in Microbiology 01/2011; 2:278. · 3.90 Impact Factor
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    ABSTRACT: Persistent infection with hepatitis C virus causes serious liver diseases, such as chronic hepatitis, hepatic cirrhosis and hepatocellular carcinoma. The male gender is one of the critical factors in progression of hepatic fibrosis due to chronic HCV infection; thus female hormones may play a role in delaying the progression of hepatic fibrosis. It has also been reported that women are more likely than men to clear HCV in the acute phase of infection. These observations lead the present authors to the question: do female hormones inhibit HCV infection? In this study using HCV J6/JFH1 and Huh-7.5 cells, the possible inhibitory effect(s) of female hormones such as 17β-estradiol (the most potent physiological estrogen) and progesterone on HCV RNA replication, HCV protein synthesis and production of HCV infectious particles (virions) were analyzed. It was found that E₂, but not P₄, significantly inhibited production of the HCV virion without inhibiting HCV RNA replication or HCV protein synthesis. E₂-mediated inhibition of HCV virion production was abolished by a nuclear estrogen receptor (ER) antagonist ICI182780. Moreover, treatment with the ERα-selective agonist 4, 4', 4″- (4-propyl-[1H]-pyrazole-1, 3, 5-triyl)trisphenol (PPT), but not with the ERβ-selective agonist 2, 3-bis (4-hydroxyphenyl)-propionitrile (DPN) or the G protein-coupled receptor 30 (GPR30)-selective agonist 1-(4-[6-bromobenzo 1, 3 dioxol-5-yl]-3a, 4, 5, 9b-tetrahydro-3H-cyclopenta [c] quinolin-8-yl)-ethanone (G-1), significantly inhibited HCV virion production. Taken together, the present results suggest that the most potent physiological estrogen, E₂, inhibits the production of HCV infectious particles in an ERα-dependent manner.
    Microbiology and Immunology 11/2010; 54(11):684-90. · 1.55 Impact Factor

Publication Stats

484 Citations
110.50 Total Impact Points

Institutions

  • 2012
    • Suez Canal University
      Al Ismā‘īlīyah, Al Ismā‘īlīyah, Egypt
    • University of Indonesia
      • Physiology
      Depok, West Java, Indonesia
  • 2011
    • Kobe University
      • Division of Microbiology
      Kōbe, Hyōgo, Japan
  • 2009
    • Lanzhou General Hospital
      Kao-lan-hsien, Gansu Sheng, China
    • Fourth Military Medical University
      Xi’an, Liaoning, China
  • 2005
    • Osaka City University
      Ōsaka, Ōsaka, Japan