Figure 4

Involvement of PI3K in H. pylori -mediated Akt activation and p65 phosphorylation. (A) MKN45 cells were pretreated for 60 min with LY294002 (20 μM) or medium alone, and infected with H. pylori (ATCC 49503) for the indicated times (30–180 min). Cells were harvested, lysed and subjected to immunoblotting with the indicated antibodies. Akt in vitro kinase assays were performed as shown in Figure 3A. (B) LY294002 had no effect on the H. pylori-stimulated DNA binding activity of NF-κB. MKN45 cells were pretreated for 60 min with LY294002 (20 μM) or medium alone, and infected with H. pylori (ATCC 49503) for the indicated times for EMSA (10–60 min). (C) H. pylori stimulated the formation of a p65–p50 heterodimer in MKN45 cells infected with H. pylori (ATCC 49503) for 60 min. The cells were lysed and the competition and supershift assays were performed with the competitor oligonucleotides and the indicated antibodies (Ab), respectively.