Figure 3 Urocortin II (UcnII) stimulates IL8 expression in human colonic epithelial cells via the nuclear factor‐κB (NF‐κB)‐ and mitogen activated protein (MAP) kinase‐dependent pathways. (A) ΙκBα, phospho p65 and phospho ERK (extracellularly regulated kinase) 1/2 expression in NCM460/CRHR2α cells treated with UcnII (10−7 M) for the indicated times as determined by western blot analysis. (B) Interleukin (IL)8 promoter transcription activity in NCM460/CRHR2α cells transfected with wild‐type IL8 promoter (IL8 WT), IL8 promoter with a mutated NF‐κB‐binding site (IL8 NF‐κBmut) and vector (PGL3 basic) after stimulation with UcnII (10−7 M) with or without astressin 2B for 6 h (*p<0.05, **p<0.01). (C) IL8 concentration (ng/ml) was determined using a human IL8 ELISA assay in NCM460/CRHR2α cells stimulated with UcnII (10−7 M) for 6 h with or without astressin 2B or the ERK1/2 antagonist PD98059 (*p<0.05).