FIGURE 4.

A, 24 h glucose starvation activates the expression of ER stress-response genes Ddit3 and Atf4, and increases Fgf21 mRNA in Hepa-1 cells. B, ICZ exposure results in a dose-dependent suppression of Fgf21 expression in glucose-starved Hepa-1 cells. For this experiment, cells were re-treated with ICZ after 12 h. C, in glucose-starved Hepa-1 cells, 24 h TCDD exposure also suppresses Fgf21 expression in a dose-dependent manner. Treatment groups were performed in triplicate, and the data presented are representative of data from at least two independent experiments. Statistical analyses were performed using one-way ANOVA; significance *, p < 0.05; **, p < 0.01; ***, p < 0.001.