title: Extracellular signal-regulated kinase induces phosphorylation of IkappaBalpha in Helicobacter pylori-infected gastric epithelial AGS cells.
abstract: In Helicobacter pylori (H. pylori)-induced gastric ulceration, NF-kappaB regulates the expression of inflammatory genes. NF-kappaB is activated by phosphorylation of its endogenous inhibitor, IkappaBalpha. The possible involvement of mitogen-activated protein kinase (MAPK) on NF-kappaB activation has been suggested in various cells. Present study aims to investigate whether H. pylori in a Korean isolate induces phosphorylation of IkappaBalpha and whether H. pylori-induced phosphorylation of IkappaBalpha is mediated by MAPK in gastric epithelial AGS cells. AGS cells were treated with MAPK inhibitors (U0126 for extracellular signal-regulated kinase, SB203580 for p38 kinase, SP600125 for c-Jun NH2-terminal protein kinases) and stimulated with H. pylori. As a result, H. pylori increased phospho-specific IkappaBalpha accompanied with the decrease in control IkappaBalpha. H. pylori-induced phosphorylation of IkappaBalpha was inhibited by treatment of U0126, but not by SB203580 or SP600125. In conclusion, extracellular signal-regulated kinase induces phosphorylation of IkappaBalpha in H. pylori-infected AGS cells.
authors.affiliation: Department of Pharmacology and Institute of Gastroenterology, Brain Korea 21 Project for Medical Sciences, College of Medicine Yonsei University, Seoul, 20-52, Korea.
authors.forename: S O
authors.initials: SO
authors.lastname: Cho
authors.forename: K H
authors.initials: KH
authors.lastname: Kim
authors.forename: H
authors.initials: H
authors.lastname: Kim
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D004269:DNA, Bacterial; D004847:Epithelial Cells / Q000201:enzymology; D005753:Gastric Mucosa / Q000201:enzymology; D016481:Helicobacter Infections / Q000473:pathology*; D016480:Helicobacter pylori / Q000472:pathogenicity*; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D010766:Phosphorylation
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D016328:NF-kappa B; D051550:I-kappa B Kinase; D020928:Mitogen-Activated Protein Kinases