Extended Data Fig. 3: Expression of active p38γ in hepatocytes reverts liver proliferation in AlbCre-p38γ mice.
From: p38γ is essential for cell cycle progression and liver tumorigenesis
AlbCre control mice, AlbCre-p38γ mice and AlbCre-p38γ mice infected with AAV expressing active p38γ (AlbCre-p38γ AAVp38γ*) were subjected to 70% PHx or a sham procedure. a, Gained liver mass, liver weight and liver:body mass ratio were measured 15 days after PHx and expressed as mean ± s.e.m. Gained liver mass: AlbCre mice, n = 8; and AlbCre-p38γ mice, n = 5; Liver:body weight: AlbCre mice, n = 9; AlbCre-p38γ mice, n = 5; Liver weight: AlbCre mice, n = 9; AlbCre-p38γ mice, n = 5. Comparisons were performed using a two-sided Student’s t-test; *P < 0.05; **P < 0.01. b, BrdU incorporation quantified by cytometry. Data are mean ± s.e.m. n = 3. Comparisons were performed using a one-way ANOVA coupled to Bonferroni’s post-tests; ***P < 0.001; *P < 0.05; **P < 0.01. c, pRb Ser795 immunostaining in livers 48 h after PHx. Left, representative images. Scale bar, 100 μm. Right, quantification. Data are mean ± s.e.m. n = 5 mice. Comparisons were made by one-way ANOVA coupled to Bonferroni’s post-tests; ***P < 0.001. d, Immunoblot analysis of liver extracts with antibodies against phospho-Rb S807/S811, Rb, p38γ and vinculin (as a loading control). Each lane corresponds to a different mouse. The data are representative of at least three independent experiments. e, Liver:tibia length ratio, expressed as mean ± s.e.m. n = 6 mice. Comparisons were made by one-way ANOVA coupled to Bonferroni’s post-tests; *P < 0.05; **P < 0.01. f, Hepatocyte proliferation analysed by Ki67 immunostaining 48 h after PHx. Left, representative images. Scale bar, 100 μm. Right, quantification of Ki67-positive cells, shown as mean ± s.e.m. Comparisons were performed using a one-way ANOVA coupled to a Kruskal–Wallis post-test. g, Wild-type mice infected with AAV expressing active p38γ (AAVp38γ*) or active p38α (AAVp38α*) were subjected to 70% PHx. Rb phosphorylation at the specified residues was assessed by western blot 48 h after PHx. Anti haemagglutinin (HA)-tag antibody was used as control of liver infection by AAVp38γ* and AAVp38α*; each lane corresponds to a different mouse. The data are representative of at least three independent experiments. h, Left, hepatocyte proliferation 48 h after PHx was studied by Ki67 immunostaining (top) or BrdU incorporation (bottom) in immunohistological liver sections. Scale bar, 100 μm. Right, quantification of Ki67- and BrdU-positive cells, shown as mean ± s.e.m. n = 5 counted areas from AlbCre mice: 0 h, n = 4; 48 h, n = 4; AlbCre-p38γ mice: 0 h, n = 3; 48 h, n = 3; AlbCre-p38γ AAVp38γ* mice: 0 h, n = 3; 48 h, n = 3; n = 5–25 counted areas from wild-type AAVp38γ* mice: n = 4; and wild-type AAVp38α* mice: n = 2. Comparisons were performed using a two-sided Student’s t-test; ***P < 0.001; *P < 0.05; **P < 0.01.
