Fig. 6.

Nrf2 siRNA but not ATF4 siRNA reduces sterubin-induced increases in cell survival. HT22 cells were transfected with control siRNA, ATF4 siRNA or Nrf2 siRNA 24 h before seeding. (A) Nuclear extracts from untreated and sterubin-treated (4 h, 10 µM) cells were analyzed by Western blotting for Nrf2 or ATF4 with actin as a loading control. (B–D) Transfected HT22 cells in 96-well plates were treated with 5 mM glutamate (B), 10 µM tBOOH (C) or 750 µM H₂O₂(D) and the indicated concentrations of sterubin. MTT reduction was measured after 24 h. Results in (B)–(D) are the average of three independent experiments. ** p < 0.01 relative to control siRNA transfection.