Fig. 3. Gadd45β expression in FL-N/35 mice transgenic for the entire HCV open reading frame.

(A) Western blot analysis of Gadd45β expression in FL-N/35 and wt mice using representative samples from each genotype. Nuclear extracts of isolated livers were analyzed for Gadd45β and lamin A/C expression, and bands corresponding to these proteins are indicated. (B) Liver-specific Gadd45β mRNA expression in untreated and benzo[a]pyrene-treated wt and FL-N/35 mice. The expression levels of Gadd45β, GusB, GAPDH and HPRT1 were determined by quantitative real-time PCR. The results were normalized to expression of GAPDH, GusB and HPRT1, and the mean±SEM mRNA quantities are expressed in relation to untreated wt controls. Statistical significance was analyzed using a Mann-Whitney nonparametric test. (C) Gadd45β promoter activity in FL-N/35 hepatocytes. Isolated hepatocytes from wt or FL-N/35 animals were cotransfected with pmaxGFP and a plasmid expressing firefly luciferase under the control of either the human Gadd45β promoter (pGL2-Gadd45β-luc) or the SV40 promoter (pGL2), and either mock irradiated or treated with UV-C. The mean±SEM luciferase levels (normalized to GFP expression) from three independent experiments are shown relative to those obtained in untreated wt hepatocytes. The statistical significances of the data were analyzed with a Mann-Whitney nonparametric test.