Figure 6.
Inhibition of NAD(P)H oxidase partially blocks NF-κB activation. (A) Human ECs were transfected with a plasmid containing the luciferase gene under the control of the NF-κB promoter and an internal control. Then cells were preincubated with NAD(P)H oxidase inhibitor (apocynin, 1 mM), or sphingosine kinase inhibitor (SPKI, 10 μM) and stimulated with TNF-α (1 ng/mL) for 6 hours. Luciferase activity was measured and normalized to internal control to eliminate the transfection variation (n = 8–12). #P < 0.05 compared with None. *P < 0.05 compared with vehicle. (B) ECs were pretreated with apocynin or sphingosine kinase inhibitor as in (A). Cells were then stimulated with TNF-α for 2 hours, and CCL2 mRNA was determined by semiquantitative PCR (n = 3). #P < 0.05 compared with None. *P < 0.05 compared with vehicle.