Korean J Gastroenterol.
2002 May;39(5):324-334.
Expression of Inducible Nitric Oxide Synthase and Nitric Oxide Production in Human Gastric Epithelial Cells Infected with Helicobacter pylori
- Affiliations
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- 1Department of Microbiology and Institute of Biomedical Science, Hanyang University College of Medicine, Seoul, Korea. hyunchae@plaza.snu.ac.kr
- 2Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
Abstract
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BACKGROUND/AIMS: Nitric oxide (NO) is known to be an important regulator of inflammatory response. Our aim was to study the role of inducible nitric oxide synthase (iNOS) expression and NO production in Helicobacter pylori (H. pylori)-infected gastric epithelial cells.
METHODS
Human gastric epithelial Hs746T cells were infected with H. pylori and iNOS mRNA expression was assessed by quantitative RT-PCR. NO production was assayed by determining nitrite/nitrate levels in culture supernatants. To determine the polarity of NO secretion, Caco-2 cells were cultured in transwell chambers and NO production was measured.
RESULTS
iNOS mRNA and NO production were significantly increased in the cells infected with H. pylori. The specific MAP kinase inhibitors decreased H. pylori-induced iNOS and NO up-regulation. After polarized Caco-2 epithelial cells were infected with H. pylori, NO was released predominantly into the apical compartment, and IL-8 was released predominantly into basolateral compartment. The addition of IFN-gamma to H. pylori-infected Caco-2 cells showed a synergistically apical and basolateral NO release.
CONCLUSIONS
These results suggest that apical NO production in H. pylori-infected gastric epithelial cells may influence the bacteria and basolateral production of NO may play a role in the tissue inflammation.