Key points are not available for this paper at this time.
Background Clinical studies demonstrate synergistic liver damage by alcohol and hepatitis C virus ( HCV ); however, the mechanisms by which alcohol promotes HCV infection remain obscure. The liver‐specific micro RNA ‐122 (miR‐122) regulates HCV replication and expression of host genes, including Cyclin G 1. Here, we hypothesized that alcohol regulates mi R ‐122 expression and thereby modulates HCV RNA replication. Methods The J 6/ JFH / H uh‐7.5 model of HCV infection was used in this study. Real‐time quantitative polymerase chain reaction , Western blotting, electrophoretic mobility shift assay, and confocal microscopy were used for experimental analysis. Results We found that acute alcohol exposure (25 mM) significantly increased intracellular HCV RNA as well as mi R ‐122 levels in H uh‐7.5 and H uh‐7.5/ CYP 2 E 1 expressing cells in the presence and absence of J 6/ JFH ‐ HCV infection. Expression of the mi R ‐122 target, Cyclin G 1, was inhibited by alcohol both in J 6/ JFH ‐infected and uninfected H uh‐7.5 cells. The use of a mi R ‐122 inhibitor increased Cyclin G 1 expression and prevented the alcohol‐induced increase in HCV RNA and protein levels, suggesting a mechanistic role for alcohol‐induced mi R 122 in HCV replication. We discovered that si RNA ‐mediated silencing of Cyclin G 1 significantly increased intracellular HCV RNA levels compared with controls, suggesting a mechanistic role for Cyclin G 1 in HCV replication. Alcohol‐induced increase in mi R ‐122 was associated with increased nuclear translocation and DNA binding of the nuclear regulatory factor‐κ B and could be prevented by NF ‐κ B inhibition. Conclusions Our novel data indicate a mi R ‐122‐mediated mechanism for alcohol increasing HCV RNA replication. We show for the first time that Cyclin G 1, a mi R ‐122 target gene, has regulatory effects on HCV replication and that alcohol increases HCV replication by regulating mi R ‐122 and Cyclin G 1.
Hou et al. (Mon,) studied this question.