Figure 2.

Loss of hepatic Atf4 alters the integrated stress response in liver. (A, B) Average ratios of hepatic phosphorylated eukaryotic initiation factor 2α (eIF2α) (p-S51) to total eIF2α in male (A) and female (B) mice without or with liver-specific knockdown of Atf4 (Atf4^fl/fl and lsAtf4KO, respectively). Mice were fed either a control (Ctrl) diet or subjected to dietary sulfur amino acid restriction (SAAR) for 10-wk. Representative immunoblots are shown above summary bar charts. Ratios are expressed as relative to the respective Ctrl-fed Atf4^fl/fl groups for male and female mice. (C, D) Hepatic mRNA concentrations of Atf3, Atf4, Atf5, Asns, and Chop (Ddit3), relative to the respective Atf4^fl/fl Ctrl-fed group for each specific gene, in male (C) and female (D) mice following the 10-wk experimental period. n = 5–12/group. *P < 0.05 with a main effect of diet. ^#P < 0.05 with a main effect of genotype. n.s. indicates no statistically significant differences at α = 0.05, as determined by two-factor ANOVA. In case of a statistical interaction effect (between diet and genotype), groups not sharing a common letter indicate a statistically significant difference between groups as determined by post hoc analysis using pairwise t tests with Bonferroni correction. Bar chart values are presented as mean ± SEM with individual data points overlaid. Boxplots indicate median values, with upper and lower hinges representing the 25th and 75th percentiles, respectively, and with upper and lower whiskers reaching to the largest and smallest values, respectively, while not extending further than 1.5 times the interquartile range, with individual data points overlaid.