Abstract | BACKGROUND AND AIM: Although interferon-alpha (IFN-alpha) is an effective treatment for hepatitis B virus (HBV) infection, its precise mechanism of action has not been identified. In this study, we investigated the role of signal transduction pathways in the activation of anti-HBV responses mediated by IFN-alpha. METHODS: Using an oligo microarray, we found that four genes in the IFN-alpha signal pathway were markedly upregulated by IFN-alpha in human hepatoma cells regardless of whether they had been transfected with a plasmid containing the HBV genome: signal transducers and activators of transcription 1 (STAT1), interferon regulatory factor-9 (IRF-9, also called ISGF3gamma or P48), IFN-alpha-inducible protein 15 (IFI-15) and IFN-alpha-inducible protein 6-16 (IFI-6-16). We also investigated the role of IFN-stimulated gene factor3 (ISGF3) complex in IFN-alpha-mediated anti-HBV responses in human hepatoma cells by measuring the mRNA of the three genes within ISGF3 (STAT1, STAT2 and IRF-9) using semiquantitative reverse-transcription PCR (RT-PCR), and expression of the three proteins by western blot, and the mRNA and protein of dsRNA-dependent protein kinase (PKR). RESULTS: STAT1, STAT2, IRF-9 and PKR mRNA as well as protein levels were upregulated by IFN-alpha treatment. When cells were pretreated with genistein, STAT1, STAT2 and IRF-9 mRNA levels remained unchanged after IFN-alpha stimulation, but PKR mRNA levels decreased, and the expression of the STAT1, P-STAT2, IRF-9 and PKR proteins decreased. Levels of HBV DNA decreased in the supernatants of cells treated with IFN-alpha, while ISGF3 levels increased. The quantity of HBV DNA remained unchanged by pretreating with genistein. CONCLUSIONS: These observations suggested that the Janus tyrosine kinase-STAT (JAK-STAT) pathway may play a major role in mediating the effects of IFN-alpha against HBV, and that ISGF3 might be a key factor.
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Authors | Quan Zhang, Yan Wang, Lai Wei, Dong Jiang, Jiang Hua Wang, Hui Ying Rao, Ling Zhu, Hongsong Chen, Ran Fei, Xu Cong |
Journal | Journal of gastroenterology and hepatology
(J Gastroenterol Hepatol)
Vol. 23
Issue 11
Pg. 1747-61
(Nov 2008)
ISSN: 1440-1746 [Electronic] Australia |
PMID | 17559358
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Antiviral Agents
- Cytokines
- DNA, Viral
- Hepatitis B Surface Antigens
- Hepatitis B e Antigens
- IFI6 protein, human
- IRF9 protein, human
- Interferon alpha-2
- Interferon-Stimulated Gene Factor 3, gamma Subunit
- Interferon-alpha
- Mitochondrial Proteins
- Protein Kinase Inhibitors
- RNA, Messenger
- Recombinant Proteins
- STAT1 Transcription Factor
- STAT1 protein, human
- STAT2 Transcription Factor
- STAT2 protein, human
- Ubiquitins
- ISG15 protein, human
- Genistein
- Janus Kinases
- eIF-2 Kinase
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Topics |
- Antiviral Agents
(pharmacology)
- Cell Line, Tumor
- Cytokines
(metabolism)
- DNA, Viral
(biosynthesis)
- Gene Expression Profiling
(methods)
- Genistein
(pharmacology)
- Hepatitis B Surface Antigens
(metabolism)
- Hepatitis B e Antigens
(metabolism)
- Hepatitis B virus
(drug effects, genetics, immunology)
- Hepatocytes
(drug effects, immunology, virology)
- Humans
- Interferon alpha-2
- Interferon-Stimulated Gene Factor 3, gamma Subunit
(genetics, metabolism)
- Interferon-alpha
(pharmacology)
- Janus Kinases
(antagonists & inhibitors, metabolism)
- Mitochondrial Proteins
(metabolism)
- Oligonucleotide Array Sequence Analysis
- Phosphorylation
- Protein Kinase Inhibitors
(pharmacology)
- RNA, Messenger
(metabolism)
- Recombinant Proteins
- STAT1 Transcription Factor
(metabolism)
- STAT2 Transcription Factor
(metabolism)
- Signal Transduction
(drug effects, genetics)
- Time Factors
- Transfection
- Ubiquitins
(metabolism)
- Virus Replication
(drug effects)
- eIF-2 Kinase
(metabolism)
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