RKIP enhances <i>H. pylori</i> mediated apoptosis.

<p>(A) Western blot analysis of AGS transiently transfected with RKIP for 24 h then infected with <i>H. pylori</i> for 6 h. Densitometry analysis for the average of 2 independent experiments indicated a 1.53 fold increase in apoptosis (average intensity of 0.19 vs 0.295) in <i>H. pylori</i> infected cells; 2.1 fold increase (average intensity of 0.19 vs 0.403) in cells transfected with RKIP; a 2.6 fold increase (average intensity of 0.19 vs 0.495) in cells infected with <i>H. pylori</i> and transiently transfected with RKIP when normalized to actin. In parallel apoptosis was measured by (B) flow cytometry. C) An ELISA based DNA fragmentation assay was used to measure apoptosis. Compared to empty vector control in (B) apoptosis was increased by <i>* H. pylori</i>, p<0.0008; ** RKIP, p<0.003; *** <i>H. pylori</i> and RKIP, p<0.0005. In (C) compared to empty vector controls, apoptosis was significantly increased by: * <i>H. pylori</i>, p<0.000063; ** RKIP, p<0.006; <i>*** H. pylori</i> and RKIP, p<0.0007. The data for B and C represents the mean +/− sd of 2 independent experiments performed in duplicate. (D) Western blot analysis of AGS cells infected with Lentivirus to knock down RKIP expression prior to 6 h infection with <i>H. pylori</i>. CTR = uninfected AGS cells, HP = AGS cells infected with <i>H. pylori</i>, KD = AGS cells infected with lentivirus to knockdown RKIP, KD+RKIP AGS cells infected with lentivirus to knockdown RKIP and infected with <i>H. pylori</i> for 16 h. (E) Apoptosis (by DNA fragmentation ELISA) was measured after 16 h of <i>H. pylori</i> infection. Apoptosis was significantly increased by <i>H. pylori</i> in AGS cells *p<0.0007; and in AGS cells with RKIP knockdown, **p<0.003 and was decreased comparing <i>H. pylori</i>-infected RKIP knockdown AGS cells with <i>H. pylori</i>-infected parental AGS cells, #p<0.0006. The data shown represents the mean +/− sd of 2 experiments performed in triplicate.