FIGURE 6.

Involvement of CREB and C/EBPβ in HCV-mediated activation of PEPCK transcription. A, equal amounts of protein extracts (whole cell or nuclear) were collected from Huh7, Huh.8, and Ava.1 cell lines and subjected to Western blot analysis with CREB or pCREB (Ser-133). Representative blots are shown. B, Huh7 and Huh.8 cells were infected with recombinant adenovirus encoding dominant-negative CREB (Ad-ACREB) or Ad-GFP control and transfected with PEPCK-LUC. Luciferase activities of PEPCK-LUC were then measured and compared in both cell lines. The values are presented as the means ± S.E. *, p < 0.05 (n = 3). C, equivalent amounts of nuclear protein extract were collected from Huh7 and Huh.8 cell lines and subjected to Western blot analysis with C/EBPβ. Representative blots are presented. D, Huh.8 cells were infected with nontargeted or C/EBPβ shRNA adenoviruses, and expression of C/EBPβ was analyzed by Western blot. The values are presented as the means ± S.E. *, p < 0.05 (n = 2). E, comparison of transcription factor gene expression under C/EBPβ knockdown conditions in Huh7 and Huh.8 cells. RNA expression was analyzed by qPCR in Huh7 and Huh.8 cells, and the data was normalized to RPL13A expression. The values are presented as the means ± S.E. *, p < 0.05 Adcntl versus AdC/EBPβ (n = 3–5).