幽门螺杆菌过氧化氢酶对SW480细胞中NF-κB和ERK通路的影响

Effects of H.pylori recombinant catalase on NF-κB and ERK pathway in colon epithelial cell line SW480

目的观察重组幽门螺杆菌(Helicobacter pylori,Hp)过氧化氢酶(catalase,CAT)对SW480细胞内核转录因子(nuclear factor,NF)κB和细胞外信号调节激酶(extrocellular-signal regulated pro- tein kinase,ERK)通路的影响。方法用脂多糖(LPS)刺激SW480细胞,再用CAT预孵育和处理;采用免疫组织化学方法检测细胞内NF-κB的表达水平,应用Western blot方法检测细胞质内IκB的蛋白表达量,电泳迁移率改变分析(electrophoretic mobility shift assay,EMSA)观察NF-κB的激活;应用激光共聚焦显微镜和Western blot方法观察ERK的核内外易位及磷酸化。结果重组Hp CAT与商品化CAT的作用相同,预孵后,NF-κB的表达和激活较LPS组和处理组明显减少,ERK核内易位和磷酸化亦明显减少,但较正常对照组仍明显增加。结论Hp CAT能够抑制NF-κB和ERK通路。

Objective To investigate the effects of recombinant Helicobacter pylori （ H. pylori） catalase （CAT） on expression and activation of nuclear factor κB and extrocellular-signal regulated protein kinase（ERK） in intestinal epithehal cells. Methods SW480 cells were stimulated by LPS. The NF-κB expression was determined by immunohistochemical staining with an NF-κB antibody. The activation of NF-κB in cells was evaluated by electrophoretic mobility shift assay（EMSA）. The translocation of ERK was observed by using laser scaning confocal microscopy（ISCM）. The phosphorylation of ERK1/2 was determined by Western blot. Results The efficacy of recombinant H.pylori CAT are equal to the purified bovine hepatic CAT（Sigma company）. Comparing with the cells treated by LPS alone, both NF-κB and ERK were suppressed in the cells pre-treated with CAT. Conclusion CAT may reduce the stress response in intestinal epithelial cells mediated by NF-κB and ERK pathway.