15d-PGJ2 increases Mn-induced Nrf2 expression in astrocytes. Astrocytes were pretreated with (A) 15 d-PGJ2 (10 µM) for 2 h or (B) LY29004 (20 µM) for 1 h before treatment with Mn (500 µM) for 6 h, followed by Western blot analysis. (C) Time course of Nrf2 protein expression. Astrocytes were pretreated for 2 h with 15 d-PGJ2 (10 µM) before treatment with Mn (500 µM; several time points, up to 120 min). Nuclear and cytosolic fractions were probed for Nrf2 proteins by Western blot analysis. Data are means±SEM (n=4). *p<0.05, ***p<0.001 compared to the controls; ##p<0.01, ###p<0.001 compared to the matched groups; ^p<0.05, ^^^p<0.001; •••p<0.001; @p<0.05, @@@p<0.01.