• Journal of Life Science
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• v.19 no.7
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• pp.949-955
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• 2009

Mucosal epithelia sense external stress signals and transmit them to the intracellular cascade responses. Ribotoxic stress-producing chemicals such as deoxynivalenol (DON) or other trichothecene mycotoxins have been linked with gastrointestinal inflammatory diseases by Fusarium-contamination. The purpose of this study was to test the hypothesis that DON evokes the epithelial sentinel signals of RNA-dependent protein kinase (PKR) and early growth response gene 1 (EGR-1), which together contribute to the pro-inflammatory cytokine interleukin 8 (IL-8) in human intestinal epithelial cells. PKR suppression by the dominant negative PKR expression attenuated DON-stimulated interleukin-8 production. Moreover, 1L-8 transcriptional activation by DON was also reduced by PKR inhibition in the human intestinal epithelial cells. Treatment with the PKR inhibitor also suppressed EGR-1 promoter activity, mRNA and protein induction, although mitogen-activated protein (MAP) kinases such as extracellular signal-regulated protein kinases (ERK) 1/2, p38, c-Jun N-terminal Kinase (INK) were little affected or even enhanced in presence of a PKR inhibitor. These patterns were also compared in the EGR-1-suppressed cells, which showed much more suppressed production of 1L-8. All things taken into consideration, DON-activated sentinel signals of EGR-1 via PKR mediated interleukin-8 production in human intestinal epithelial cells, which provide insight into the possible general mechanism associated with mucosal inflammation as an intestinal toxic insult by ribotoxic trichothecene mycotoxins.