Abstract
Abstract Helicobacter pylori (H. pylori) colonizes the human stomach and can cause gastric diseases such as chronic atrophic gastritis, peptic ulcers and even gastric cancer later in life. Cytotoxin-associated gene A (CagA), a virulence factor of H. pylori, associates with gastric disease and increases the risk of developing gastric adenocarcinoma. Infection of H. pylori regulates adherens junction regulatory proteins and results in destabilized epithelial cell adherence and increased rates of migration in human gastric epithelial cells. Recently, phosphorylation of caveolin-1 on tyrosine 14 is found to correlate with adhesion-dependent signaling and cell migration. However, the phosphorylation status of caveolin-1 after H. pylori infection is unclear. This study thus focuses on investigating whether phosphorylation of caveolin-1 on tyrosine 14 in host cells induced by H. pylori and whether CagA is involved in this event. Furthermore, the phosphorylation status of ERK induced by H. pylori infection was also investigated. H. pylori strain 26695 and isogenic cagA knockout strain were used for analyzing the effect of CagA on phosphorylation of caveolin-1 and phosphorylation of ERK in human epithelial cells. Caveolin-1 and ERK was found to be dephosphorylated in epithelial cells after H. pylori infection. These events were CagA-independent regulation of signaling. These results give us a preliminary evidence that phosphorylated caveolin-1 is involved in H. pylori-induced signal transduction pathway in epithelial cells.