The role of CagA on H.pylori-induced IL-8 production from gastric epithelial cells / 中国病理生理杂志

ABSTRACT

AIM: To investigate the role of CagA and the effect of small interference RNA (siRNA) on the release of IL-8 in H. pylori-infected gastric epithelial cells. METHODS: siRNA were transferred into CagA positive strain H. pylori NCTC 11637 by using electroporation. The CagA positive strain NCTC 11637 and the CagA negative strain NCTC 11639 were co-cultured with gastric epithelial cells and the level of IL-8 in the supernatant was measure by ELISA. RT-PCR and Western blotting were performed to detect CagA expression. RESULTS: The level of IL-8 induced by CagA positive strain NCTC 11637 was higher than the level induced by CagA negative strain NCTC 11639 ( 1 200.00 ?32.51) ng/L vs (100.00?8.58) ng/L, P0.05). Meanwhile, CagA mRNA decreased significantly in siRNAⅢgroup. The levels of CagA mRNA at 6, 12, and 24 h after electroporation were 31.3% (0.270/0.861), 57.6% (0.496/0.861), and 73.9% (0.637/0.861) of the control levels, respectively. Inhibition rate by siRNAⅢ was 68.7%. The Western blotting result in siRNA Ⅲ group showed that the level of CagA protein degraded to 30.7% (0.4/1.3) at 12 h after electroporation. In siRNA V group, the expression of CagA mRNA at 6 h is suppressed by 23.1% (P