FIG. 8.
Acute liver-specific inhibition of G9a activity by G9a-DN disrupted bile acid homeostasis and derepresses Cyp7a1 and Cyp8b1 in mice fed cholic acid. About 1 × 109 active viral particles (Ad-G9a-DN or Ad-empty) were injected into a mouse tail vein, and 3 days after infection, mice were fed normal or 0.5% cholic acid-containing chow for 5 h or 24 h. Liver, gall bladder, and small intestine were collected for further analyses. (A) Liver nuclear extracts were prepared from 3 mice for each group infected with Ad-empty or Ad-G9a-DN virus and immunoprecipitated with SHP antibody (Ab) or control IgG. The immunoprecipitates were used as the source of enzyme in in vitro HMT assays. GST-H3(1-84) (WT) or GST-H3 mutant (H3R9) was used as histone substrates. The HMT reaction samples were analyzed as described in the legend of Fig. 2A. (B) Total bile acid pool size was measured from bile acid levels in gall bladder, liver, and the entire small intestine in mice fed normal or 0.5% cholic acid-supplemented chow for 5 h or 24 h. Total bile acid pool size was determined as described in Materials and Methods. The standard errors of the mean from samples from 3 mice are shown. 
, P < 0.05; NS, statistically not significant. (C and D) Mice were infected with either Ad-G9a-DN or Ad-empty virus, and 3 days later, mice were fed normal or 0.5% cholic acid-containing chow for 5 h or 24 h. As a control, normal uninfected mice were also analyzed in parallel. Total RNA was isolated from liver and subjected to quantitative real-time RT-PCR using primer sets specific for Cyp7a1, Cyp8b1, and SHP, and the amounts of PCR product were divided by the amounts of 36B4 PCR product. The standard error of the mean is shown for samples from 6 mice for 5 h feeding and from 3 mice for 24 h feeding groups. Differences between Ad-empty- and Ad-G9a-DN-infected samples were analyzed by a Student t test. , P < 0.05; NS, statistically not significant.