Anti-HBV Activity Of INF-alpha Is Negatively Regulated By Liver-specific MicroRNA MiR-122

Hepatitis B Virus (HBV, Hepatitis B Virus) infection, one of the common infectious diseases, which not only cause acute, chronic viral hepatitis and liver fibrosis, but has close associations with the development of Hepatic carcinoma, threats human health.For present, there are two kinds of drugs used to treat Hepatitis B:Interferons and Nucleoside analog. Interferons (IFNs), a kind of highly active multifunctional glycoprotein, are produced by those cells, which are induced by the interferon induced biological agents. Greenberg et al first reported in1976that after appling human leukocyte interferon to treat four patients with chronically active hepatitis B, two patients’HBeAg had gone. Since then, IFNs have been regarded as one of the preferred anti-HBV drugs; and IFNs have received much satisfactory therapeutic effect in Europe. However, only20-30%of the hepatitis B sufferer are sensitive to IFNs treatment in Asia. Previous research findings reported that IFNs can regulate microRNA-122expression in heaptocytes, and microRNA-122is closely related with HBV replication. By appling Real-time PCR, Nanodrop and the like, our research work aimed to study the possible mechanism of microRNA-122mediated suppression of HBV replication by IFN-alpha.First of all, by in vitro with IFN-alpha treatment Huh7cells and then detection of microRNA-122expression by real-time PCR, our research found that1000IU/ml IFN-a can significantly down regulated microRNA-122expression in Huh7cells. Secondly, we constructed pSuper-miR-122eukaryotic expression vector successfully. Through co-transfection pSuper-miR-122or miR-122-mimic and HBV1.3into HepG2cells, we found that miR-122can inhibit HBV replication in vitro. Meanwhile, co-transfection miR-122-inhibitor with HBV1.3into Huh7cells, the result showed that miR-122-inhibitor can notablely facilitate HBV replication in Huh7cells. Both results demonstrated the conclusion that miR-122can inhibit HBV replication in vitro. Thirdly, to explore why miR-122can inhibit HBV replication, co-transfected HBV-luci reporter gene and miR-122into Huh7cells, we found that miR-122might act on the5non-coding region of HBV-C. Finally, we practised comprehensive experiments of miR-122, IFNs and HBV, and obtained the conclusion that microRNA-122negatively mediates suppression of HBV replication by IFN-alpha. The result offers a new pathway to treat hepatitis B, mainly embodying two aspects:firstly, it is possible to promote the capability of IFN to cure hepatitis B through some means to offset the negative regulation made by miR-122in the course of IFN anti-HBV replication; secondly, it is also possible to design RNA drug from miR-122self for hepatitis B treatment directly.