Expression of nuclear factor-kappa B in Helicobacter pylori-infected gastric mucosa detected with Southwestern histochemistry

Background: The transcription factor nuclear factor-kappa B (NF-kappa B) pl ays a pivotal role in inflammatory responses by upregulating mRNA expressio n of, for example, proinflammatory cytokines and chemokines. Although in vi tro studies have shown that Helicobacter pylori can induce NF-kappa B activ ation in gastric cancer cell lines, there is little information on cellular localization of NF-kappa B in H. pylori-infected gastric mucosa. Methods: H. pylori-infected and -negative patients with various endoscopic findings were examined. NF-kappa B expression was studied by means of Southwestern h istochemistry, a new method of localizing transcription factors. Labeled do uble-stranded oligo-DNA with specific consensus sequence for the NF-kappa B binding site was reacted with frozen sections from gastric biopsy specimen s. We compared mucosal interleukin-8 (IL-8) and IL-1 beta levels as measure d with enzyme-linked immunosorbent assay with the degree of NF-kappa B expr ession. Results: NF-kappa B expression was often evident in nuclei of epith elial cells in H. pylori-infected gastric mucosa. The degree of NF-kappa B expression on the epithelium was significantly more severe in H. pylori-inf ected than in -negative mucosa. The degree of NF-kappa B expression also co rrelated with mucosal IL-8 levels but not with IL-1 beta. Conclusions: H. p ylori infection increases the expression of NF-kappa B in gastric mucosa, s uggesting that NF-kappa B is involved in inflammatory responses to H. pylor i.