The C-X-C chemokine ENA-78 is preferentially expressed in intestinal epithelium in inflammatory bowel disease

Background & Aims: Secretion of chemokines by epithelial cells may represent a crucial event in the pathogenesis of inflammatory bowel disease (IBD). Expression of the chemokine epithelial neutrophil-activating peptide 78 (ENA-78) was monitored in patients with IBD and normal controls. Methods: In situ hybridizations were performed on 41 tissue specimens from 15 patients with IBD and 10 controls to detect ENA-78 messenger RNA (mRNA). Immunofluorescence stainings were used to localize ENA-78 protein. Results: Intestinal epithelial cells expressing ENA-78 mRNA at detectable levels ave found at comparable frequencies in patients with Crohn's disease and ulcerative colitis. Tissue specimens with mild to moderate histological signs of disease activity show slightly higher frequencies of ENA-78 mRNA-expressing epithelial cells than areas with signs of severe disease activity (P = 0.14). Immunofluorescence stainings showed presence of the ENA-78 protein in >90% of preserved epithelial cells in IBD. In control tissues, ENA-78 mRNA was not detectable, and ENA-78 protein was detectable in 0%-30% of epithelial cells. Conclusions: The observations are in agreement with a role of the C-X-C chemokine ENA-78 in the pathogenesis of IBD.