Background and Aims: Transcription factors of the nuclear factor κB (NF-κB) family play an important role in the regulation of genes involved in inflammation. In inflammatory bowel diseases, proinflammatory cytokines known to be regulated by NF-κB are involved. The aim of this study was to investigate the role of NF-κB activation during mucosa inflammation in situ. Methods: A monoclonal antibody, α-p65mAb, was applied for immunofluorescence and immunohistochemical analysis that recognizes activated NF-κB. Electrophoretic mobility shift assay was used to directly demonstrate the presence of active DNA-binding NF-κB. Results: Using the α-p65mAb antibody, activated NF-κB could be found in biopsy specimens from inflamed mucosa but was almost absent in uninflamed mucosa. The number of cells showing NF-κB activation correlated with the degree of mucosal inflammation but was not significantly different between inflamed mucosa from patients with Crohn's disease, ulcerative colitis, and nonspecific colitis or diverticulitis. NF- κB activation was localized in macrophages and in epithelial cells as identified by double-labeling techniques. Electrophoretic mobility shift assay with isolated lamina propria mononuclear cells and epithelial cells confirmed these results. Conclusions: This study shows for the first time the activation of NF-κB during human mucosal inflammation in situ. In addition to macrophages, epithelial cells contained activated NF-κB, indicating an involvement in the inflammatory process.
Rogler, G., Brand, K., Vogl, D., Page, S., Hofmeister, R., Andus, T., … Gross, V. (1998). Nuclear factor κB is activated in macrophages and epithelial cells of inflamed intestinal mucosa. Gastroenterology, 115(2), 357–369. https://doi.org/10.1016/S0016-5085(98)70202-1