C/EBP-β and p50-NFκB mediate the induction of the CRP promoter by IL-1.

(A) The fragment of the human CRP core promoter containing the overlapping REs for C/EBP-β and p50-NFκB. (B) HuH7 cells were transfected with the wild-type human CRP promoter construct pCRP-luc and the mutated constructs pCRPΔp50NF-κB-luc and pCRPΔC/EBP-β-luc, as indicated, and subsequently were stimulated with IL-1. (C) Dose-dependent 18-hour stimulation of HuH7 cells with IL-1, as indicated, and Western blot analysis of p50-NFκB and C/EBP-β in nuclear extracts. Levels of histone H1 are shown for confirmation of equal loading. (D) HuH7 cells were transfected with pCRP-luc in the presence of p50-NFκB and C/EBP-β expression vectors or control vector (Con) and were stimulated with 10 ng/mL IL-1 for 18 hours. Luciferase activities represent means ± SDs of several (3 or more) transfection experiments.