Fig. 2

PTP1B attenuation of PAF-induced IL-8 promoter activation depends on a C/EBPß binding site. a HEK-PAFR were co-transfected with WT PTP1B or vector control and pGL3-IL-8 WT or deleted for C/EBPß-binding site (ΔC/EBPß) or AP-1-binding site (ΔAP-1). Cells were starved overnight in DMEM+ 0.2% BSA and stimulated for 6 h with PAF (100 nM) or vehicle and luciferase activity was measured. Data are presented as mean ± S.E.M of fold increase of at least 3 experiments. Significance was established with paired two-way ANOVA with Sidak post-test: *:p < 0.05. b HEK-PAFR were transfected with pGL3 IL-8 WT or ΔC/EBPß, incubated for 20 min with 10 μM PTP1B inhibitor or its vehicle, then stimulated for 6 h with PAF (100 nM) and luciferase activity was measured. Results are presented as the % of variation of PAF-induced fold increase of promoter activity caused by PTP1B inhibitor. Stimulated control cell promoter activity was set at 1. Data are presented as mean ± S.E.M of at least 4 experiments. Significance was established for pGL3-IL-8 WT and ΔC/EBPß with Mann-Whitney test. *:p > 0.05