Dataset Information

Modulation of Cell Death Pathways by Hepatitis C Virus Proteins in Huh7.5 Hepatoma Cells.

ABSTRACT: The hepatitis C virus (HCV) causes chronic liver disease leading to fibrosis, cirrhosis, and hepatocellular carcinoma. HCV infection triggers various types of cell death which contribute to hepatitis C pathogenesis. However, much is still unknown about the impact of viral proteins on them. Here we present the results of simultaneous immunocytochemical analysis of markers of apoptosis, autophagy, and necrosis in Huh7.5 cells expressing individual HCV proteins or their combinations, or harboring the virus replicon. Stable replication of the full-length HCV genome or transient expression of its core, ?1/?2, NS3 and NS5B led to the death of 20-47% cells, 72 h posttransfection, whereas the expression of the NS4A/B, NS5A or NS3-NS5B polyprotein did not affect cell viability. HCV proteins caused different impacts on the activation of caspases-3, -8 and -9 and on DNA fragmentation. The structural core and E1/E2 proteins promoted apoptosis, whereas non-structural NS4A/B, NS5A, NS5B suppressed apoptosis by blocking various members of the caspase cascade. The majority of HCV proteins also enhanced autophagy, while NS5A also induced necrosis. As a result, the death of Huh7.5 cells expressing the HCV core was induced via apoptosis, the cells expressing NS3 and NS5B via autophagy-associated death, and the cells expressing E1/E2 glycoproteins or harboring HCV the replicon via both apoptosis and autophagy.

SUBMITTER: Masalova OV

PROVIDER: S-EPMC5713315 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Modulation of Cell Death Pathways by Hepatitis C Virus Proteins in Huh7.5 Hepatoma Cells.

Masalova Olga V OV Lesnova Ekaterina I EI Solyev Pavel N PN Zakirova Natalia F NF Prassolov Vladimir S VS Kochetkov Sergey N SN Ivanov Alexander V AV Kushch Alla A AA

International journal of molecular sciences 20171106 11

The hepatitis C virus (HCV) causes chronic liver disease leading to fibrosis, cirrhosis, and hepatocellular carcinoma. HCV infection triggers various types of cell death which contribute to hepatitis C pathogenesis. However, much is still unknown about the impact of viral proteins on them. Here we present the results of simultaneous immunocytochemical analysis of markers of apoptosis, autophagy, and necrosis in Huh7.5 cells expressing individual HCV proteins or their combinations, or harboring t ...[more]

PMID: 29113144

Similar Datasets

Project description:Hepatitis C virus (HCV) directly induces oxidative stress and liver injury. Bach1, a basic leucine zipper mammalian transcriptional repressor, negatively regulates heme oxygenase 1 (HMOX1), a key cytoprotective enzyme that has antioxidant and anti-inflammatory activities. microRNAs (miRNAs) are small noncoding RNAs ( approximately 22 nt) that are important regulators of gene expression. Whether and how miRNAs regulate Bach1 or HCV are largely unknown. The aims of this study were to determine whether miR-196 regulates Bach1, HMOX1, and/or HCV gene expression. HCV replicon cell lines (Con1 and 9-13) of the Con1 isolate and J6/JFH1-based HCV cell culture system were used in this study. The effects of miR-196 mimic on Bach1, HMOX1, and HCV RNA, and protein levels were measured by way of quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting, respectively. The Dual Glo Luciferase Assay System was used to determine reporter activities. miR-196 mimic significantly down-regulated Bach1 and up-regulated HMOX1 gene expression and inhibited HCV expression. Dual luciferase reporter assays demonstrated that transfection of miR-196 mimic resulted in a significant decrease in Bach1 3'-untranslated region (UTR)-dependent luciferase activity but not in mutant Bach1 3'-UTR-dependent luciferase activity. Moreover, there was no detectable effect of mutant miR-196 on Bach1 3'-UTR-dependent luciferase activity.miR-196 directly acts on the 3'-UTR of Bach1 messenger RNA and translationally represses the expression of this protein, and up-regulates HMOX1. miR-196 also inhibits HCV expression in HCV replicon cell lines (genotype 1b) and in J6/JFH1 (genotype 2a) HCV cell culture system. Thus, miR-196 plays a role in both HMOX1/Bach1 expression and the regulation of HCV expression in human hepatocytes. Overexpression of miR-196 holds promise as a potential novel strategy to prevent or ameliorate hepatitis C infection, and to protect against liver injury in chronic HCV infection.

Project description:HCV infection is a major cause of chronic liver disease and liver cancer in the United States. To address the pathogenesis caused by HCV infection, recent studies have focused on the direct cytopathic effects of individual HCV proteins, with the objective of identifying their specific roles in the overall pathogenesis. However, this approach precludes examination of the possible interactions between different HCV proteins and organelles. To obtain a better understanding of the various cytopathic effects of and cellular responses to HCV proteins, we used human hepatoma cells constitutively replicating HCV RNA encoding either the full-length polyprotein or the non-structural proteins, or cells constitutively expressing the structural protein core, to model the state of persistent HCV infection and examined the combination of various HCV proteins in cellular pathogenesis. Increased reactive oxygen species (ROS) generation in the mitochondria, mitochondrial injury and degeneration, and increased lipid accumulation were common among all HCV protein-expressing cells regardless of whether they expressed the structural or non-structural proteins. Expression of the non-structural proteins also led to increased oxidative stress in the cytosol, membrane blebbing in the endoplasmic reticulum, and accumulation of autophagocytic vacuoles. Alterations of cellular redox state, on the other hand, significantly changed the level of autophagy, suggesting a direct link between oxidative stress and HCV-mediated activation of autophagy. With the wide-spread cytopathic effects, cells with the full-length HCV polyprotein showed a modest antioxidant response and exhibited a significant increase in population doubling time and a concomitant decrease in cyclin D1. In contrast, cells expressing the non-structural proteins were able to launch a vigorous antioxidant response with up-regulation of antioxidant enzymes. The population doubling time and cyclin D1 level were also comparable to that of control cells. Finally, the cytopathic effects of core protein appeared to focus on the mitochondria without remarkable disturbances in the cytosol.

Dataset Information

Modulation of Cell Death Pathways by Hepatitis C Virus Proteins in Huh7.5 Hepatoma Cells.

Publications

Modulation of Cell Death Pathways by Hepatitis C Virus Proteins in Huh7.5 Hepatoma Cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets