Interestingly, we found

that ethanol synergized with HCV to significantly increase protein levels of HSP90 (Fig. 5A). Inhibition of HSP90 with 17-DMAG (Fig. 5A) or an HSP90-specific siRNA (Fig. 5B) reduced HCV protein (Fig. 5A,B) and RNA (Supporting Fig. 5A) levels in J6/JFH1-infected Huh7.5 cells as well as in Con1/FL replicon cells (data not shown). The efficiency of HSP90 knockdown was confirmed in alcohol-naïve and alcohol-treated Huh7.5 or J6/JFH1-Huh7.5 cells at protein (Fig. 5B) and RNA (Fig. 5C) levels. DMAG treatment (Fig. 5D) or knockdown of HSP90 (Fig. 5E) also significantly decreased miR-122 levels. HSP90 knockdown was also associated with a decrease in GW182 RNA (Fig. 5F) and protein (Supporting Fig. 5B), and this closely correlated with a significant reduction in intracellular HCV RNA (Supporting GPCR Compound Library Fig. 5A) and HCV NS3 protein (Fig. 5B). The concentrations of 17-DMAG, HSP90 siRNA, and GW182 siRNA used showed no toxicity to cells (Supporting Fig. 6A,B). Using Huh7.5 cells and the HCV J6/JFH system, we found that acute ethanol (25 mM) treatment resulted in Deforolimus purchase a significant increase in HCV RNA (Fig. 1C) and HCV NS3 protein expression (Fig.

1D) compared with ethanol-naïve matching controls. The ethanol concentration used did not induce cytotoxicity as assessed by light microcopy cell morphology and LDH-Cytotoxicity assay (data not shown). miR-122, a highly abundant microRNA in hepatocytes, has been shown to modulate HCV replication,9 and we recently found that microRNA expression can be regulated learn more by alcohol in Kupffer cells and in liver tissue in vivo.13 Based on our

earlier observation that ethanol treatment significantly up-regulated miR-122 levels in Huh7.5 cells with and without HCV J6/JFH1 infection (Fig. 2D), we hypothesized that ethanol affects miR-122 expression and thereby regulates HCV replication. The functional role of the ethanol-induced miR-122 increase in HCV replication was evaluated by using an anti–miR-122 inhibitor. Our results show that the anti–miR-122 inhibitor, and not the anti–miR-122 negative control, attenuated HCV replication in ethanol-naïve cells and prevented the ethanol-induced increase in HCV RNA (Fig. 6A) and HCV NS3 protein levels (Fig. 6B). These observations suggest that alcohol-induced miR-122 induction has a mechanistic role in regulating HCV replication. In this study, we report a novel mechanism in which ethanol regulates GWB proteins and enhances HCV replication in human hepatoma cells involving GW182 and HSP90. We demonstrate here that alcohol increases HSP90, GW182, and miR-122 that are host factors in the regulation of HCV infection.