AMPK-dependent pathway activation is necessary for IL-22-mediated autophagy and cytoprotection in L02 cells treated with APAP. (A) L02 cells were pretreated with compound C (4 μM) for 6 h, incubated with IL-22 (400 ng/mL) for another 1 h, followed by treatment with APAP (5 mM) for 6 h. Western blot analysis showed cellular protein expressions of p-STAT3, STAT3, p-AMPK, AMPK, and LC3-I/II. GAPDH served as a loading control. (B) Quantification of the LC3-II to GAPDH expression ratio. (C) L02 cells were pretreated with compound C (4 μM) for 6 h, incubated with IL-22 (400 ng/mL) for another 1 h, followed by treatment with APAP (5 mM) for 24 h. Then, LDH levels released in culture medium from L02 cells were measured. Data are presented as means ± SEM; p value was calculated by one-way ANOVA (B-C), *p < 0.05, ***p < 0.001.