CBP and p300 overexpression enhanced COX-2 protein levels and promoter activities in HFb and RAW 264.7. (A) CBP and p300 protein levels in transduced HFb. HFb were transfected with plasmids encoding p300, CBP, or the empty vector (mock control) and then treated with or without PMA, IL-1β, or LPS. Protein levels of p300 were analyzed by Western blots. CBP or p300 level in mock-transfected cells was similar to that in native cells. (B) Influence of p300 and CBP transduction on COX-2 protein levels in HFb. (C) Effect of p300 and CBP transduction on COX-2 promoter activities in HFb. HFb were cotransfected with luciferase expression vectors and plasmids encoding p300 or CBP. The promoter activity was expressed as relative light unit (RLU). (D) CBP and p300 protein levels in RAW 264.7 cells transfected with CBP or p300 vectors. (E) Influence of p300 and CBP transduction on COX-2 protein levels in RAW 264.7 cells. (F) Effect of p300 or CBP overexpression on COX-2 promoter activity. In panels A, B, D, and E, the top panel shows a representative of 3 experiments and the bottom panel shows mean ± SEM of the densitometry from 3 experiments. Each bar in panels C and F also denotes mean ± SEM of 3 experiments.