Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic...Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic function approximation （GFA） method of variable selection was used to generate the model. Highly statistically significant model with r^2 = 0.966 and r^2cv = 0.951 was obtained when the number of descriptors in the equation was set to 5. High r^2pred value of 0.884 indicates the good predictive power of the best model. Spatial descriptors of radius of gyration （RadOfGration）, molecular volume （Vm）, length of molecule in the z dimension （Shadow-Zlength）, thermodynamic descriptors of the octanol/water partition coefficient （LogP） and molecular refractivity index （MR） showed enormous contributions to HCV NS5B polymerase inhibition. The validation of the model was done by leave-one-out （LOO） test, randomization tests and external test set prediction. The model gives insight on indispensable structural requirements for the activity and can be used to design more potent analogs against HCV NSSB polymerase.展开更多
Objective: To explore inhibitory effects of genome-specific, chemically synthesized siRNAs(small interference RNA) against NS3 gene of hepatitis C virus(HCV) 1a genotype in stable Huh-7(human hepatoma) cells as well a...Objective: To explore inhibitory effects of genome-specific, chemically synthesized siRNAs(small interference RNA) against NS3 gene of hepatitis C virus(HCV) 1a genotype in stable Huh-7(human hepatoma) cells as well as against viral replication in serum-inoculated Huh-7 cells. Methods: Stable Huh-7 cells persistently expressing NS3 gene were produced under antibiotic gentamycin(G418) selection. The cell clones resistant to 1 000 μg antibiotic concentration(G418) were picked as stable cell clones. The NS3 gene expression in stable cell clone was confirmed by RT-PCR and Western blotting. siRNA cell cytotoxicity was determined by MTT cell proliferation assay. Stable cell lines were transfected with sequence specific siRNAs and their inhibitory effects were determined by RT-PCR, real-time PCR and Western blotting. The viral replication inhibition by siRNAs in serum inoculated Huh-7 cells was determined by real-time PCR. Results: RT-PCR and Western blot analysis confirmed NS3 gene and protein expression in stable cell lines on day 10, 20 and 30 post transfection. MTT cell proliferation assay revealed that at most concentrated dose tested(50 nmol/L), siRNA had no cytotoxic effects on Huh-7 cells and cell proliferation remained unaffected. As demonstrated by the siRNA time-dependent inhibitory analysis, siRNA NS3-is44 showed maximum inhibition of NS3 gene in stable Huh-7 cell clones at 24(80%, P=0.013) and 48 h(75%, P=0.002) post transfection. The impact of siRNAs on virus replication in serum inoculated Huh-7 cells also demonstrated significant decrease in viral copy number, where siRNA NS3-is44 exhibited 70%(P<0.05) viral RNA reduction as compared to NS3-is33, which showed a 64%(P<0.05) decrease in viral copy number. siRNA synergism(NS3-is33 + NS3-is44) decreased viral load by 84%(P<0.05) as compared to individual inhibition by each siRNA(i.e., 64%–70%(P<0.05) in serum-inoculated cells. Synthetic siRNAs mixture(NS5Bis88 + NS3-is33) targeting different region of HCV genome(NS5B and NS3) also decreased HCV viral load by 85%(P< 0.05) as compared to siRNA inhibitory effects alone(70% and 64% respectively, P<0.05). Conclusions: siRNAs directed against NS3 gene significantly decreased m RNA and protein expression in stable cell clones. Viral replication was also vividly decreased in serum infected Huh-7 cells. Stable Huh-7 cells expressing NS3 gene is helpful to develop anti-hepatitis C drug screening assays. siRNA therapeutic potential along with other anti-HCV agents can be considered against hepatitis C.展开更多
AIM:To study the subtype prevalence and the phylogenetic relatedness of hepatitis C virus(HCV)sequences obtained from the Argentine general population,a large cohort of individuals was analyzed.METHODS:Healthy Argenti...AIM:To study the subtype prevalence and the phylogenetic relatedness of hepatitis C virus(HCV)sequences obtained from the Argentine general population,a large cohort of individuals was analyzed.METHODS:Healthy Argentinian volunteers(n=6251)from 12 provinces representing all geographical regions of the country were studied.All parents or legal guardians of individuals younger than 18 years provided informed written consent for participation.The corresponding written permission from all municipal authorities was obtained from each city or town where subjects were to be included.HCV RNA reverse transcription-polymerase chain reaction products were sequenced and phylogenetically analyzed.The 5’untranslated region(5’UTR)was used for RNA detection and initial genotype classification.The NS5B polymerase region,encompassing nt 8262-8610,was used for subtyping.RESULTS:An unexpectedly low prevalence of HCV infection in the general population(0.32%)was observed.Our data contrasted with previous studies that reported rates ranging from 1.5%to 2.5%,mainly performed in selected populations of blood donors or vulnerable groups.The latter values are in keeping with the prevalence reported by the 2007 Argentinian HCV Consensus(approximately 2%).HCV subtypes weredistributed as follows:1a(25%),1b(25%),2c(25%),3a(5%),and 2j(5%).Two isolates ascribed either to genotype 1(5%)or to genotype 3(5%)by 5’UTR phylogenetic analysis could not be subtyped.Subtype 1a sequences comprised a highly homogeneous population and clustered with United States sequences.Genotype1b sequences represented a heterogeneous population,suggesting that this genotype might have been introduced from different sources.Most subtype 2c sequences clustered close to the 2c reported from Italy and Southern France.CONCLUSION:HCV has a low prevalence of 0.32%in the studied general population of Argentina.The pattern of HCV introduction and transmission in Argentina appears to be a consequence of multiple events and different for each subtype.展开更多
Over the last decade, the standard of care for the treat- ment of chronic hepatitis C has been the combination of pegylated-interferon-alfa （PEG-IFN） and ribavirin （RBV） which results in sustained virological resp...Over the last decade, the standard of care for the treat- ment of chronic hepatitis C has been the combination of pegylated-interferon-alfa （PEG-IFN） and ribavirin （RBV） which results in sustained virological response （SVR） rates of 75%-85% in patients with genotypes 2 or 3 but only of 40%-50% in patients with genotype 1. Cur- rently, there are rapid and continuous developments of numerous new agents against hepatitis C virus （HCV）, which are the focus of this review. Boceprevir and tela- previr, two first-generation NS3/4A HCV protease inhibi- tors, have been recently licensed in several countries around the world to be used in combination with PEG- IFN and RBV for the treatment of genotype 1 patients. Boceprevir or telaprevir based triple regimens, com- pared with the PEG-IFN/RBV combination, improve the SVR rates by 25%-31% in treatment-naTve genotype 1 patients, by 40%-64% in prior relapsers, by 33%-45% in prior partial responders and by 24%-28% in prior null responders. At the same time, the application of response-guided treatment algorithms according to the on-treatment virological response results in shortening of the total therapy duration to only 24 wk in 45%-55% of treatment-na＇ive patients. There are, however, several challenges with the use of the new triple combinations in genotype 1 patients, such as the need for immediate results of HCV RNA testing using sensitive quantitative assays, new and more frequent adverse events （anemia and dysgeusia for boceprevir; pruritus, rash and anemia for telaprevir）, new drug interactions and increasing dif- ficulties in compliance. Moreover, the SVR rates are still poor in very difficult to treat subgroups of genotype 1 patients, such as null responders with cirrhosis, while there is no benefit for patients who cannot tolerate PEG- IFN/RBV or who are infected with non-1 HCV genotype. Many newer anti-HCV agents of different classes and numerous combinations are currently under evaluation with encouraging results. Preliminary data suggest that the treatment of chronic HCV patients with well toler- ated combinations of oral agents without PEG-IFN is feasible and may lead to a universal HCV cure over the next 5-10 years.展开更多
GBV C/HGV is a newly identified virus associated with human hepatitis In this study, the nucleotide sequences of the partial NS5 gene of GBV C/HGV derived from sera of 8 Chinese patien...GBV C/HGV is a newly identified virus associated with human hepatitis In this study, the nucleotide sequences of the partial NS5 gene of GBV C/HGV derived from sera of 8 Chinese patients were determined The nucleotide homology among the 8 isolates were 92% on average On the basis of sequence analysis, two sets of oligonucleotide primers derived from highly conserved region of GBV C/HGV NS5 gene were designed to establish both sensitive and specific nested PCR for detection of GBV C/HGV RNA 253 Chinese patients were examined for the virus RNA GBV C/HGV RNA positive rates in patients infected with HBV, HCV and patients with chronic non B,non C hepatitis were 18 4%, 19 8% and 8 9% respectively This result suggested that HBV,HCV and GBV C/HGV shared the same transmission risk factors 8 patients with GBV C/HGV and HCV coinfection were retrospectively observed for the response to interferon Coinfection with GBV/HGV did not negatively influence the responsiveness of HCV, and GBV C/HGV was sensitive to interferon to a certain degree展开更多
Hepatitis C virus(HCV) affects 3% of the world population. It represents the main cause of chronic liver disease and is responsible for extra-hepatic complications, such as type 2 diabetes and cardiovascular diseases....Hepatitis C virus(HCV) affects 3% of the world population. It represents the main cause of chronic liver disease and is responsible for extra-hepatic complications, such as type 2 diabetes and cardiovascular diseases. HCV includes 7 genotypes differing in the nucleotide sequence variability, the geographic distribution, the rates of viral clearance, the risk of progression to liver fibrosis and to hepatocellular carcinoma, and the response to therapy. Last years have seen remarkable advances in the field of HCV infection with the approval of direct antiviral agents(DAAs) targeting key viral proteins involved in the HCV replication. Several oral regimens combining DAAs from different families have been developed and these regimens showed increased and sustained virological response rates to above 90% reducing the treatment duration to 12 wk or less. In particular, sofosbuvir, a nucleotide analogue nonstructural(NS)5B polymerase inhibitor, and velpatasvir, a NS5 A inhibitor, have been tested in two phase 3 trials, the ASTRAL-2(against HCV genotype 2) and the ASTRAL-3(against HCV genotype 3), demonstrating to be effective, safe, and well tolerated in patients who were 18 years of age or older and had at least a 6-mo history of HCV infection with a compensated liver disease.展开更多
Hepatitis C virus(HCV) infects approximately 180 million people worldwide. Significant progress has been made since the establishment of in vitro HCV infection models in cells. However, the replication of HCV is compl...Hepatitis C virus(HCV) infects approximately 180 million people worldwide. Significant progress has been made since the establishment of in vitro HCV infection models in cells. However, the replication of HCV is complex and not completely understood. Here, we found that the expression of host prion protein(Pr P) was induced in an HCV replication cell model. We then showed that increased Pr P expression facilitated HCV genomic replication. Finally, we demonstrated that the KKRPK motif on the N-terminus of Pr P bound nucleic acids and facilitated HCV genomic replication. Our results provided important insights into how viruses may harness cellular protein to achieve propagation.展开更多
基金supported by the National Natural Science Foundation of China (No. 30500339)Natural Science Foundation of Zhejiang Province (NO.Y407308)the Sprout Talented Project Program of Zhejiang Province (No. 2008R40G2020019)
文摘Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic function approximation （GFA） method of variable selection was used to generate the model. Highly statistically significant model with r^2 = 0.966 and r^2cv = 0.951 was obtained when the number of descriptors in the equation was set to 5. High r^2pred value of 0.884 indicates the good predictive power of the best model. Spatial descriptors of radius of gyration （RadOfGration）, molecular volume （Vm）, length of molecule in the z dimension （Shadow-Zlength）, thermodynamic descriptors of the octanol/water partition coefficient （LogP） and molecular refractivity index （MR） showed enormous contributions to HCV NS5B polymerase inhibition. The validation of the model was done by leave-one-out （LOO） test, randomization tests and external test set prediction. The model gives insight on indispensable structural requirements for the activity and can be used to design more potent analogs against HCV NSSB polymerase.
文摘Objective: To explore inhibitory effects of genome-specific, chemically synthesized siRNAs(small interference RNA) against NS3 gene of hepatitis C virus(HCV) 1a genotype in stable Huh-7(human hepatoma) cells as well as against viral replication in serum-inoculated Huh-7 cells. Methods: Stable Huh-7 cells persistently expressing NS3 gene were produced under antibiotic gentamycin(G418) selection. The cell clones resistant to 1 000 μg antibiotic concentration(G418) were picked as stable cell clones. The NS3 gene expression in stable cell clone was confirmed by RT-PCR and Western blotting. siRNA cell cytotoxicity was determined by MTT cell proliferation assay. Stable cell lines were transfected with sequence specific siRNAs and their inhibitory effects were determined by RT-PCR, real-time PCR and Western blotting. The viral replication inhibition by siRNAs in serum inoculated Huh-7 cells was determined by real-time PCR. Results: RT-PCR and Western blot analysis confirmed NS3 gene and protein expression in stable cell lines on day 10, 20 and 30 post transfection. MTT cell proliferation assay revealed that at most concentrated dose tested(50 nmol/L), siRNA had no cytotoxic effects on Huh-7 cells and cell proliferation remained unaffected. As demonstrated by the siRNA time-dependent inhibitory analysis, siRNA NS3-is44 showed maximum inhibition of NS3 gene in stable Huh-7 cell clones at 24(80%, P=0.013) and 48 h(75%, P=0.002) post transfection. The impact of siRNAs on virus replication in serum inoculated Huh-7 cells also demonstrated significant decrease in viral copy number, where siRNA NS3-is44 exhibited 70%(P<0.05) viral RNA reduction as compared to NS3-is33, which showed a 64%(P<0.05) decrease in viral copy number. siRNA synergism(NS3-is33 + NS3-is44) decreased viral load by 84%(P<0.05) as compared to individual inhibition by each siRNA(i.e., 64%–70%(P<0.05) in serum-inoculated cells. Synthetic siRNAs mixture(NS5Bis88 + NS3-is33) targeting different region of HCV genome(NS5B and NS3) also decreased HCV viral load by 85%(P< 0.05) as compared to siRNA inhibitory effects alone(70% and 64% respectively, P<0.05). Conclusions: siRNAs directed against NS3 gene significantly decreased m RNA and protein expression in stable cell clones. Viral replication was also vividly decreased in serum infected Huh-7 cells. Stable Huh-7 cells expressing NS3 gene is helpful to develop anti-hepatitis C drug screening assays. siRNA therapeutic potential along with other anti-HCV agents can be considered against hepatitis C.
基金Supported by Argentinian Fresenius Medical Care CentreSpanish Ministry of Science and Innovation(MINECO)Grants+2 种基金SAF2009-10403Spanish Ministry of Health(FIS)PI10/01505 and 09/0899
文摘AIM:To study the subtype prevalence and the phylogenetic relatedness of hepatitis C virus(HCV)sequences obtained from the Argentine general population,a large cohort of individuals was analyzed.METHODS:Healthy Argentinian volunteers(n=6251)from 12 provinces representing all geographical regions of the country were studied.All parents or legal guardians of individuals younger than 18 years provided informed written consent for participation.The corresponding written permission from all municipal authorities was obtained from each city or town where subjects were to be included.HCV RNA reverse transcription-polymerase chain reaction products were sequenced and phylogenetically analyzed.The 5’untranslated region(5’UTR)was used for RNA detection and initial genotype classification.The NS5B polymerase region,encompassing nt 8262-8610,was used for subtyping.RESULTS:An unexpectedly low prevalence of HCV infection in the general population(0.32%)was observed.Our data contrasted with previous studies that reported rates ranging from 1.5%to 2.5%,mainly performed in selected populations of blood donors or vulnerable groups.The latter values are in keeping with the prevalence reported by the 2007 Argentinian HCV Consensus(approximately 2%).HCV subtypes weredistributed as follows:1a(25%),1b(25%),2c(25%),3a(5%),and 2j(5%).Two isolates ascribed either to genotype 1(5%)or to genotype 3(5%)by 5’UTR phylogenetic analysis could not be subtyped.Subtype 1a sequences comprised a highly homogeneous population and clustered with United States sequences.Genotype1b sequences represented a heterogeneous population,suggesting that this genotype might have been introduced from different sources.Most subtype 2c sequences clustered close to the 2c reported from Italy and Southern France.CONCLUSION:HCV has a low prevalence of 0.32%in the studied general population of Argentina.The pattern of HCV introduction and transmission in Argentina appears to be a consequence of multiple events and different for each subtype.
文摘Over the last decade, the standard of care for the treat- ment of chronic hepatitis C has been the combination of pegylated-interferon-alfa （PEG-IFN） and ribavirin （RBV） which results in sustained virological response （SVR） rates of 75%-85% in patients with genotypes 2 or 3 but only of 40%-50% in patients with genotype 1. Cur- rently, there are rapid and continuous developments of numerous new agents against hepatitis C virus （HCV）, which are the focus of this review. Boceprevir and tela- previr, two first-generation NS3/4A HCV protease inhibi- tors, have been recently licensed in several countries around the world to be used in combination with PEG- IFN and RBV for the treatment of genotype 1 patients. Boceprevir or telaprevir based triple regimens, com- pared with the PEG-IFN/RBV combination, improve the SVR rates by 25%-31% in treatment-naTve genotype 1 patients, by 40%-64% in prior relapsers, by 33%-45% in prior partial responders and by 24%-28% in prior null responders. At the same time, the application of response-guided treatment algorithms according to the on-treatment virological response results in shortening of the total therapy duration to only 24 wk in 45%-55% of treatment-na＇ive patients. There are, however, several challenges with the use of the new triple combinations in genotype 1 patients, such as the need for immediate results of HCV RNA testing using sensitive quantitative assays, new and more frequent adverse events （anemia and dysgeusia for boceprevir; pruritus, rash and anemia for telaprevir）, new drug interactions and increasing dif- ficulties in compliance. Moreover, the SVR rates are still poor in very difficult to treat subgroups of genotype 1 patients, such as null responders with cirrhosis, while there is no benefit for patients who cannot tolerate PEG- IFN/RBV or who are infected with non-1 HCV genotype. Many newer anti-HCV agents of different classes and numerous combinations are currently under evaluation with encouraging results. Preliminary data suggest that the treatment of chronic HCV patients with well toler- ated combinations of oral agents without PEG-IFN is feasible and may lead to a universal HCV cure over the next 5-10 years.
文摘GBV C/HGV is a newly identified virus associated with human hepatitis In this study, the nucleotide sequences of the partial NS5 gene of GBV C/HGV derived from sera of 8 Chinese patients were determined The nucleotide homology among the 8 isolates were 92% on average On the basis of sequence analysis, two sets of oligonucleotide primers derived from highly conserved region of GBV C/HGV NS5 gene were designed to establish both sensitive and specific nested PCR for detection of GBV C/HGV RNA 253 Chinese patients were examined for the virus RNA GBV C/HGV RNA positive rates in patients infected with HBV, HCV and patients with chronic non B,non C hepatitis were 18 4%, 19 8% and 8 9% respectively This result suggested that HBV,HCV and GBV C/HGV shared the same transmission risk factors 8 patients with GBV C/HGV and HCV coinfection were retrospectively observed for the response to interferon Coinfection with GBV/HGV did not negatively influence the responsiveness of HCV, and GBV C/HGV was sensitive to interferon to a certain degree
文摘Hepatitis C virus(HCV) affects 3% of the world population. It represents the main cause of chronic liver disease and is responsible for extra-hepatic complications, such as type 2 diabetes and cardiovascular diseases. HCV includes 7 genotypes differing in the nucleotide sequence variability, the geographic distribution, the rates of viral clearance, the risk of progression to liver fibrosis and to hepatocellular carcinoma, and the response to therapy. Last years have seen remarkable advances in the field of HCV infection with the approval of direct antiviral agents(DAAs) targeting key viral proteins involved in the HCV replication. Several oral regimens combining DAAs from different families have been developed and these regimens showed increased and sustained virological response rates to above 90% reducing the treatment duration to 12 wk or less. In particular, sofosbuvir, a nucleotide analogue nonstructural(NS)5B polymerase inhibitor, and velpatasvir, a NS5 A inhibitor, have been tested in two phase 3 trials, the ASTRAL-2(against HCV genotype 2) and the ASTRAL-3(against HCV genotype 3), demonstrating to be effective, safe, and well tolerated in patients who were 18 years of age or older and had at least a 6-mo history of HCV infection with a compensated liver disease.
基金supported by the Strategic Priority Research Program A of the Chinese Academy of Sciences(XDA12010309)the National Science Foundation of China(31670170)+1 种基金the Nature Science Foundation of Hubei Province(2015CFA087)the National Basic Research Priorities Program of China(2013CB911102)
文摘Hepatitis C virus(HCV) infects approximately 180 million people worldwide. Significant progress has been made since the establishment of in vitro HCV infection models in cells. However, the replication of HCV is complex and not completely understood. Here, we found that the expression of host prion protein(Pr P) was induced in an HCV replication cell model. We then showed that increased Pr P expression facilitated HCV genomic replication. Finally, we demonstrated that the KKRPK motif on the N-terminus of Pr P bound nucleic acids and facilitated HCV genomic replication. Our results provided important insights into how viruses may harness cellular protein to achieve propagation.
