Purpose To investigate the effects of Helicobacter pylori ( H. pylori )-CagA and the urease metabolite
NH4+ on mucin expression in AGS cells. Materials and Methods AGS cells were transfected with CagA and/or treated with different concentrations of NH 4 CL. Mucin gene and protein expression was assessed by qPCR and immunofluorescence assays, respectively. Results CagA significantly upregulated MUC5AC , MUC2 , and MUC5B expression in AGS cells, but did not affect E-cadherin and MUC6 expression. MUC5AC , MUC6 , and MUC2 expression in AGS cells increased with increasing
NH4+ concentrations until reaching a peak level at 15 mM. MUC5B mRNA expression in AGS cells (
NH4+ concentration of 15 mM) was significantly higher than that at 0, 5, and 10 mM
NH4+. No changes in E-cadherin expression in AGS cells treated with
NH4+ were noted, except at 20 mM. The expression of MUC5AC , MUC2 , and MUC6 mRNA in CagA-transfected AGS cells at an
NH4+ concentration of 15 mM was significantly higher than that at 0 mM, and decreased at higher concentrations. The expression of MUC5B mRNA increased with increases in
NH4+ concentration, and was significantly higher compared to that in untreated cells. No significant change in the expression of E-cadherin mRNA in CagA-transfected AGS cells was observed. Immunofluorescence assays confirmed the observed changes. Conclusion H. pylori may affect the expression of MUC5AC , MUC2 , MUC5B , and MUC6 in AGS cells via CagA and/or
NH4+, but not E-cadherin.