Expression of ΔN-IκBα in hepatocytes does not inhibit liver regeneration or IL-6 or STAT3 activation after PH. (a) Hepatocyte DNA synthesis. Mifepristone-treated single-transgenic and double-transgenic mice were injected with BrdU 2 hours prior to killing at the indicated times after PH. Liver sections were stained with an antibody to BrdU as described in Methods, and BrdU-positive hepatocyte nuclei were scored for 30 fields (×400) per slide. Four mice were analyzed per group, and data represent average percentage (± SEM) of BrdU-positive nuclei per group. (b) Mitotic index. Mitotic hepatocytes were counted in mifepristone-treated mice killed 48 hours after PH. Four mice were analyzed per group, and data represent average total number ± SEM of mitotic hepatocytes counted per 30 fields (×400). (c) Liver/body weight ratio. Liver and whole body weights were determined for untreated mice (no PH) or mifepristone-treated mice killed 2 weeks after PH. Three mice were used per group, and data represent average (± SEM) liver weight expressed as a percentage of whole body weight. (d) DNA synthesis at 48 hours after PH in mice injected with mifepristone at 12-hour intervals. (e) IL-6 ELISA. Serum was obtained from mifepristone-treated single- or double-transgenic mice killed at the indicated times after PH. Data represent average (± SEM) IL-6 levels per group. Three mice were analyzed per group. (f) STAT3 EMSA. Nuclear extracts were prepared from livers of mice described in e. Five micrograms of nuclear protein were analyzed for STAT3 DNA binding activity as described in Methods. Each lane represents an individual animal.