Fig. 3.

Induction and regulation of NRF2 are APE1-dependent. (A–C) Knockdown of APE1 downregulated NRF2 protein levels in CPB, OE33, and FLO1 cells. Cells were transfected with si-APE1 or sh-APE1 and controls (si-Ctrl or sh-Ctrl). Whole-cell lysates were collected for western blotting analysis of APE1, NRF2, and KEAP-1. (D–F) Relative ARE luciferase activity was determined in CPB, OE33, and FLO1 cells with or without APE1 knockdown followed by transfection with PGL3- NRF2-ARE-luc and renilla for 48 h. (G–H) FLO1 and OE33 cells were knockdown of APE1 followed by transfection with PGL3- NRF2-ARE-luc and renilla for 24 h and treatment with 200 μM bile salts cocktails for another 24 h, ARE luciferase activity was determined as previously described. (I–J) mRNA expression of NRF2 downstream genes HO-1 and TRXND1 in OE33 cells treated with and without ABS. Values are mean ± SD of three independent experiments. *P < 0.05; **P < 0.01; ***P < 0.001.