ARE -luciferase activity significantly increases by 4-HNE treatment. (A) HeLa cells were transiently transfected with ARE-luciferase construct for 24 h and treated with 0.01-10 μM 4-HNE. Cells were harvested and lysed after 6 h, and luciferase activity was measured. (B) HepG2 cells stably expressed with ARE-luciferase reporter gene were treated with 10 μM 4-HNE with or without 2 h pretreatment of 5 mM GSH. Cells were harvested and lysed after 18 h, and luciferase activity was measured. Relative fold of induction was obtained as compared to the untreated cells. *: P < 0.05.