Fig. 6

Effect of Tat-SOD on TPA- or SNP-induced promoter activity of cyclooxygenase-2 (COX-2) or nuclear factor–κB (NF-κB) in PC12 cells. PC12 cells were transfected with a luciferase reporter plasmid of (a) COX-2 or (b) NF-κB for 24 h, then incubated with Tat-SOD, indomethacin (Indo), or PTIO for 2 h. After being stimulated for 4 h with TPA (50 ng/mL) or SNP (50 mM), luciferase activity was measured, and COX-2 and NF-κB activities were expressed relative to cells treated with TPA or SNP alone. Each experiment was performed in triplicate. Data are represented as mean ± SEM. Significance was calculated compared to controls and p values were calculated by applying Student’s t-test. For the relative COX-2 luciferase activity, statistically significant difference at exposed to TPA (50 ng/mL) + Tat-SOD (0.5 μM) compared to TPA control (50 ng/mL) (**p < 0.01), very significant differences at exposed to TPA (50 ng/mL) + Tat-SOD (1.0, 1.5, 2.0 μM) or Indo (20 μg/mL) compared to TPA control (50 ng/mL) (***p < 0.001); also, statistically significant differences at exposed to SNP (50 mM) + Tat-SOD (0.5 or 1.0 μM) compared to SNP control (50 mM) (**p < 0.01), very significant differences at exposed to SNP (50 mM) + Tat-SOD (1.5 or 2.0 μM) or PTIO (50 mM) compared to SNP control (50 mM) (***p < 0.001). For the relative NF-κB Luciferase activity, statistically significant difference at exposed to TPA (50 ng/mL) + Tat-SOD (0.5 or 1.0 μM) compared to TPA control (50 ng/mL) (**p < 0.01), very significant differences at exposed to TPA (50 ng/mL) + Tat-SOD (1.5 μM) compared to TPA control (50 ng/mL) (***p < 0.001), and very significant differences at exposed to TPA (50 ng/mL) + Tat-SOD (2.0 μM) or Indo (20 μg/mL) compared to TPA control (50 ng/mL) (****p < 0.0001); also, statistically significant differences at exposed to SNP (50 mM) + Tat-SOD (0.5, 1.0, 1.5, 2.0 μM) compared to SNP control (50 mM) (****p < 0.0001), very significant differences at exposed to SNP (50 mM) + PTIO (50 mM) compared to SNP control (50 mM) (***p < 0.001)