Figure 4: Silencing of Nrf2 abrogated Protandim-induced increases in HO-1 expression. (a) Cells were treated with no RNA, control RNA, or Nrf2 siRNA prior to 12 hrs Protandim, then HO-1 expression determined by Western blotting. (b) HO-1 expression in response to Protandim treatment was elevated over 1,000% of control in the no RNA and control RNA conditions, while increases in HO-1 expression in the Nrf2 siRNA condition were negligible. ( treatments per condition). Data are presented as mean + SE percent of control (no RNA, no Protandim) condition. *   # compared to within RNA condition Protandim treatment. Ptd: Protandim, Ctr: No Protandim.