Protein Kinase C Activation by Helicobacter pylori in Human Gastric Epithelial Cells Limits Interleukin-8 Production Through Suppression of Extracellular Signal-Regulated Kinase

• Main Authors: Yoshihisa Nozawa, Katsushi Nishihara, Yushiro Akizawa, Naoki Orimoto, Motoko Nakano, Tatsuya Uji, Hirofusa Ajioka, Atsuhiro Kanda, Naosuke Matsuura, Mamoru Kiniwa
• Format: Article
• Language: English
• Published: Elsevier 2004-01-01
• Series: Journal of Pharmacological Sciences
• Online Access: http://www.sciencedirect.com/science/article/pii/S1347861319324909

Helicobacter pylori (H. pylori) infection of gastric epithelial cells has been shown to induce interleukin (IL)-8 production, but the signal transduction mechanism leading to IL-8 production has not been clearly defined. Here, we investigate the role of protein kinase C (PKC) in the mechanism of induction of IL-8 release by H. pylori in human gastric epithelial cells. In MKN45 cells, H. pylori-induced IL-8 release was enhanced by treatment with PKC inhibitors (GF109203X and calphostin C) and PKC depletion, which completely inhibited PKC activity. Moreover, PKC inhibitors and PKC depletion increased extracellular signal-regulated kinase (ERK) activity and phosphorylation, but not calcium /calmodulin-dependent protein kinase II (CaMK II) activity, in response to H. pylori infection. PKC activated by H. pylori inhibited activation of ERK induced by H. pylori without affecting the CaMK II activity and negatively regulated IL-8 production in human gastric epithelial cells. Keywords:: H. pylori, interleukin-8, protein kinase C, extracellular signal-regulated kinase, MKN45 cell