Objective: To investigate the in vitro effects of H. pylori-conditioned medium (HCM) from gastric epithelial AGS cell cultures on microglia and neuronal cells.
Material: H. pylori, human gastric epithelial AGS cells, microglia-like BV-2 cells and human neuroblastoma SH-SY5Y cells.
Treatment: Treated AGS cells with H. pylori at ratios from 1:100 to 1:900 for 24 h. Cultured BV-2 cells and SH-SY5Y cells were treated with HCM from AGS cell cultures.
Methods: Cell viability was measured by a quantitative colorimetric assay with MTT. Nitric oxide (NO) was determined by using Griess reagent. IL-8 was measured by an enzyme-linked immunosorbent assay. Protein expressions were revealed by western blot analysis.
Results: H. pylori increased IL-8, NO, COX-2 and gp91(phox) in AGS cell cultures. When BV-2 cells were cocultured with AGS cells, HCM increased COX-2, gp91(phox), iNOS and NO of BV-2 cells. HCM also enhanced the degradation of I kappaB alpha in BV-2 cells. HCM up-regulated expression of nNOS, COX-2, and gp91(phox) of SH-SY5Y cells co-cultured with BV-2 cells. Particularly, the decrease of cell viability of SH-SY5Y induced by HCM was dependent on the presence of BV-2 cells.
Conclusions: H. pylori-induced infection induces microglia-mediated inflammation and neurotoxicity. The present results suggest that microglia play a critical role in HCM-induced toxicity of neuronal SH-SY5Y cells.