Helicobacter pylori-induced expression of interleukin-8 and cyclooxygenase-2 in AGS gastric epithelial cells: Mediation by nuclear factor-kappa B

Background: Helicobacter pylori infection might activate nuclear factor-kap paB (NF-kappaB), a transcriptional regulator of inducible expression of inf lammatory genes, interleukin-8 (IL-8) and cyclooxygenase-2 (COX-2). We stud ied the role of NF-MB on expression of IL-8 and COX-2 in H, pylori-stimulat ed AGS gastric epithelial cells by using antisense oligonucleotide: (AS ODN ) for NF-kappaB subunit p50 and an antioxidant. glutathione (GSH) as well a s a NF-kappaB inhibitor, pyrrolidine dithiocarbamate (PDTC). Methods: AGS c ells were treated with p50 AS ODN. GSH or PDTC in the presence of H. pylori . mRNA expression and protein levels for IL-8 and COX-2 were determined by Northern blot analysis and Western blot analysis. Levels of IL-8. 6-keto-pr ostaglandin F-1 alpha (6-keto-PGF(1 alpha)) and thromboxane B-2 (TXB2) were measured in the medium by enzyme-linked immunosorbent assay. NF-kappaB act ivation was examined by electrophoretic mobility shift assay. Results: H. p ylori induced a time-dependent expression of mRNA and protein for IL-8 and COX-2 via activation of NF-kappaB and increased the levels of IL-8. 6-keto- PGF(1 alpha), and TXB2. which were inhibited by GSH and PDTC. H, pylori-ind uced expression of IL-8 and COX-2 was blocked in AGS cells transfected with p50 AS ODN. Conclusion: NF-h B may play a novel role in expression of IL-8 and COX-2 in H. pylori-induced gastric inflammation.