Fig. 3. G9a protects hepatocytes against apoptosis after a high dose of DEN.

A Immunohistochemical analysis of the mice liver 48 h after administering a high dose of diethylnitrosamine (DEN) (100 mg/kg i.p.). G9a is upregulated after DEN administration, and cleaved-Caspase 3 induction occurs only in the G9a^ΔHep liver, whereas γH2AX and p53 levels are comparable between wild-type (WT) and G9a^ΔHep livers. Bcl-G expression is elevated in the pericentral hepatocytes of G9a^ΔHep mice. Scale bars, 50 µm. The number of positive hepatocytes is shown in the graph below (**p < 0.01, NS not significant, Student’s t test). B Serum ALT levels are significantly elevated in G9a^ΔHep mice 48 h after administering a high dose of DEN. Data are represented as mean ± SEM (WT/DEN0h, n = 4; G9a^ΔHep/DEN0h, n = 3; WT/DEN48h, n = 5; G9a^ΔHep/DEN48h, n = 3). C Cyp2e1 expression, as assessed by qRT-PCR, is comparable between WT and G9a^ΔHep livers (each, n = 3; NS not significant, Student’s t test). D Top 10 upregulated genes in the non-tumorous area of G9a^ΔHep liver are listed. E qRT-PCR analysis validates Bcl-G upregulation in the G9a^ΔHep liver (*p < 0.05, Student’s t test). F Immunoblots reveal increased Bcl-G, cleaved-PARP, and cleaved-Caspase3 protein levels in the G9a^ΔHep liver 48 h after high-dose DEN administration. Right graph shows relative protein level of Bcl-G (each, n = 3; **p < 0.01, NS not significant, Student’s t test). G Relative expression levels of G9a and BCL-G in human non-tumorous (NT) liver obtained in our institution. BCL-G expression is negatively correlated with G9a expression. (rho = −0.37, p = 0.02, Spearman’s rank correlation coefficient).