Fig. 4

Effect of IκB kinase mutants, IKKα(K44A), and IKKβ(K44A), on the transcriptional activity of the human iNOS promoter in PVEC. Cells were cotransfected with the phiNOS-205Luc plasmid, defined in Figure 1, and expression plasmids for either or both IκB kinase mutants, as depicted. Control cultures (first set of bars) received equal amounts of expression plasmids but without the cDNA of the IκB kinase mutants. Open bars represent the expression of luciferase reporter gene in untreated cells; closed bars represent effect of IL-1β treatment. Luciferase activity is expressed relative to that achieved in untreated PVEC cotransfected with the phiNOS-205Luc plasmid and an empty expression vector. Luciferase activity was normalized to protein concentration of cell extracts. Values shown are the means ± SEM of three independent experiments.