Helicobacter pylori-induced mucosal inflammation results in high production of interleukin 17 (IL-17), a potent inducer of IL-8 in gastric epithelial cells. The aim of this study was to investigate signaling pathways by which IL-17 regulates IL-8 production in human gastric epithelial cells. Activation of mitogen-activated protein (MAP) kinases in both IL-17-stimulated MKN28 cells and epithelial cells isolated from H. pylori-colonized gastric mucosa was assessed by Western blotting. In IL-17-stimulated MKN28 cells the activation of activatior protein 1 (AP-1), nuclear factor (NF)-IL-6, and NF-κB was also assessed by electrophoretic mobility shift assay IL-8 production was evaluated by reverse transcription-PCR and enzyme-linked immunosorbent assay (ELISA) both for IL-17-stimulated MKN28 cells treated with specific MAP kinase inhibitors and gastric biopsy cultures treated with a neutralizing IL-17 antibody. Serum from H. pylori-infected patients was tested for immunoglobulin G response to CagA by ELISA. Treatment of MKN28 cells with IL-17 caused activation of extracellular signal-regulated protein kinase 1/2 (ERK 1/2) but not other MAP kinases and had the downstream effects of AP-1 and NFκ-B activation and IL-8 synthesis. Blocking ERK 1/2 activity inhibited AP-1-mediated, but not NF-κB-mediated, IL-8 induction. Enhanced activation of ERK 1/2 was seen in gastric epithelial cells isolated from H. pylori-infected patients in comparison to uninfected controls, and this was associated with high IL-8. These effects were even more pronounced in patients seropositive for CagA than in seronegative ones. In gastric biopsy cultures, the addition of a neutralizing IL-17 antibody decreased ERK 1/2 activation, thus resulting in a significant inhibition of IL-8. In H. pylori-colonized gastric epithelial cells, IL-17-induced IL-8 synthesis is associated with and depends at least in part on the activation of ERK 1/2 MAP kinase.
Sebkova, L., Pellicano, A., Monteleone, G., Grazioli, B., Guarnieri, G., Imeneo, M., et al. (2004). Extracellular signal-regulated protein kinase mediates interleukin 17 (IL-17)-induced IL-8 secretion in Helicobacter pylori-infected human gastric epithelial cells. INFECTION AND IMMUNITY, 72(9), 5019-5026 [10.1128/IAI.72.9.5019-5026.2004].
Extracellular signal-regulated protein kinase mediates interleukin 17 (IL-17)-induced IL-8 secretion in Helicobacter pylori-infected human gastric epithelial cells
MONTELEONE, GIOVANNI;PALLONE, FRANCESCO;
2004-01-01
Abstract
Helicobacter pylori-induced mucosal inflammation results in high production of interleukin 17 (IL-17), a potent inducer of IL-8 in gastric epithelial cells. The aim of this study was to investigate signaling pathways by which IL-17 regulates IL-8 production in human gastric epithelial cells. Activation of mitogen-activated protein (MAP) kinases in both IL-17-stimulated MKN28 cells and epithelial cells isolated from H. pylori-colonized gastric mucosa was assessed by Western blotting. In IL-17-stimulated MKN28 cells the activation of activatior protein 1 (AP-1), nuclear factor (NF)-IL-6, and NF-κB was also assessed by electrophoretic mobility shift assay IL-8 production was evaluated by reverse transcription-PCR and enzyme-linked immunosorbent assay (ELISA) both for IL-17-stimulated MKN28 cells treated with specific MAP kinase inhibitors and gastric biopsy cultures treated with a neutralizing IL-17 antibody. Serum from H. pylori-infected patients was tested for immunoglobulin G response to CagA by ELISA. Treatment of MKN28 cells with IL-17 caused activation of extracellular signal-regulated protein kinase 1/2 (ERK 1/2) but not other MAP kinases and had the downstream effects of AP-1 and NFκ-B activation and IL-8 synthesis. Blocking ERK 1/2 activity inhibited AP-1-mediated, but not NF-κB-mediated, IL-8 induction. Enhanced activation of ERK 1/2 was seen in gastric epithelial cells isolated from H. pylori-infected patients in comparison to uninfected controls, and this was associated with high IL-8. These effects were even more pronounced in patients seropositive for CagA than in seronegative ones. In gastric biopsy cultures, the addition of a neutralizing IL-17 antibody decreased ERK 1/2 activation, thus resulting in a significant inhibition of IL-8. In H. pylori-colonized gastric epithelial cells, IL-17-induced IL-8 synthesis is associated with and depends at least in part on the activation of ERK 1/2 MAP kinase.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
