title: NF-kappaB and Bcl-2 in Helicobacter pylori-induced apoptosis in gastric epithelial cells.
abstract: Helicobacter pylori (H. pylori) has been considered as an important pathogen of gastroduodenal inflammation and gastric carcinogenesis. However, the pathogenic mechanisms including H. pylori-induced apoptosis and subsequent molecular mechanisms have not been clarified yet. The present study examined the role of Bcl-2 and its relation to NF-kappaB in H. pylori-induced apoptosis in human gastric epithelial AGS cells. AGS cells were cultured in the presence of H. pylori, at a bacterium/cell ratio of 300:1, for the determination of apoptosis, NF-kappaB activation with IkBa degradation, and Bcl-2 level. AGS cells were transfected with a control vector (pCMV cells) or a full-length human Bcl-2 expression vector (Bcl-2 cells). H. pylori-induced apoptosis and NF-kappaB activation were compared in the wild-type cells and the transfected cells. As a result, H. pylori increased apoptotic cells with chromatin condensation and reduced Bcl-2 levels, which were accompanied with NF-kappaB activation. H. pylori induced sixfold increase in the number of apoptotic cells in wild-type cells and pCMV cells. H. pylori-induced increment of apoptotic cells were relatively lower in Bcl-2 cells than pCMV cells. H. pylori-induced NF-kappaB activation and IkBa degradation were not different in the wild-type cells, pCMV cells, and Bcl-2 cells. In conclusion, the reduced gastric Bcl-2 level may be the main pathogenic mechanism of H. pylori-induced apoptosis in gastric epithelial cells.
authors.affiliation: Department of Pharmacology and Institute of Gastroenterology, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, Korea.
authors.forename: Sang Hui
authors.initials: SH
authors.lastname: Chu
authors.forename: Joo Weon
authors.initials: JW
authors.lastname: Lim
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Kim
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma; D017209:Apoptosis / Q000502:physiology*; D045744:Cell Line, Tumor; D005753:Gastric Mucosa / Q000378:metabolism* / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori; D006801:Humans; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013274:Stomach Neoplasms; D014162:Transfection
chemical_list: D016328:NF-kappa B; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins