Korean J Anat.
2005 Feb;38(1):21-30.
Involvement of Protein Kinase C delta in Iron Chelator-Induced IL-8 Production in Human Intestinal Epithelial Cells
- Affiliations
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- 1Department of Internal Medicine, Wonkwang University School of Medicine, Iksan, Chonbuk 570-749, Korea.
- 2Department of Microbiology and Immunology, Wonkwang University School of Medicine, Iksan, Chonbuk 570-749, Korea. cdjun@wonkwang.ac.kr
- 3Department of Pathology, Wonkwang University School of Medicine, Iksan, Chonbuk 570-749, Korea.
- 4Department of Anatomy, Wonkwang University School of Medicine, Iksan, Chonbuk 570-749, Korea.
Abstract
- Our previous study demonstrated that a bacterial siderophore, deferoxamine (DFO), could trigger inflammatory signals in human intestinal epithelial cells as a single stimulus, leading to IL-8 production via ERK1/2 and p38 phosphorylation and NF-kappa B-independent mechanism. In the present study, we proved that a novel protein kinase C (PKC)isoform, PKCdelta, is necessary for DFO-induced IL-8 production. Pretreatment of HT-29 cells with rottlerin showed remarkable inhibition of DFO-induced IL-8 production. In contrast, a conventional PKC inhibitor Go6976 did not show significant inhibition of DFO-induced IL-8 production. DFO induced strong phosphorylation of PKCdelta in the epithelial cells. Overexpression of PKCdelta resulted in enhanced PKCdelta phosphorylation, while transfection with dominant-negative PKCdelta vector failed DFO-induced phosphorylation. In addition, transfection of HT-29 cells with siRNA targeting endogenous PKCdelta, which suppressed PKCdelta expression, attenuated DFO-induced IL-8 production. These results demonstrate that PKCdelta plays an important role in regulating iron chelator-induced IL-8 production in human intestinal epithelial cells.