The Role of Mitogen-activated Protein Kinase in Enteritis Induced by Bacteroides fragilis Enterotoxin.
- Author:
Jung Mogg KIM
1
;
Hwoon Yong JUNG
;
Yu Kyoung OH
;
Young Jeon KIM
Author Information
1. Department of Microbiology, Hanyang University College of Medicine, Korea. jungmogg@hanyang.ac.kr
- Publication Type:Original Article
- Keywords:
AP-1;
Bacteroides fragilis enterotoxin;
Enteritis;
MAPK
- MeSH:
Animals;
Bacterial Infections;
Bacteroides fragilis*;
Bacteroides*;
Colon;
Diarrhea;
Enteritis*;
Enterotoxins*;
Epithelial Cells;
Humans;
Ileum;
Inflammation;
Interleukin-8;
Mice;
Phosphotransferases;
Plasmids;
Protein Kinases*;
Transcription Factor AP-1
- From:Journal of Bacteriology and Virology
2005;35(1):1-10
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
A 20 kDa heat-labile toxin (BFT) produced by enterotoxigenic Bacteroides fragilis (B. fragilis) is associated with diarrhea and mucosal inflammation. Although intestinal epithelial cells are known to activate mitogen-activated protein kinase (MAPK) in response to bacterial infection, there has been little understanding on the association between MAPK activation and BFT-induced enteritis. This study was performed to investigate the role of MAPK in enteritis induced by BFT. In human colon epithelial cells, BFT increased IL-8 secretion in a dose-dependent manner. BFT activated the three main MAPK cascades, including extracellular signal-regulated kinase (ERK), p38, and c-Jun NH2-terminal kinase (JNK). BFT stimulation also activated AP-1 activation signals. Overexpression of dominant-negative plasmid of the c-Jun decreased the activated AP-1 signals and the up-regulated IL-8 expression induced by BFT stimulation. In addition, SB203580 and ERK inhibitor U0126 significantly reduced IL-8 secretion in colon epithelial cells stimulated with BFT. Furthermore, SB203580 significantly prevented BFT-induced severity of enteritis and fluid secretion in mouse ileum. These results suggest that MAPK activation may be required for IL-8 transcription in intestinal epithelial cells exposed to BFT and that the activated MAPK can mediate intestinal inflammation and mucosal damage induced by BFT.
