ROS在幽门螺杆菌对胃上皮细胞DNA损伤中的作用

Role of ROS in DNA damage caused by Helicobacter pylori in gastric epithelial cells

目的:探讨幽门螺杆菌(Helicobacter pylori,H.pylori)感染过程中活性氧(reactive oxygen species,ROS)的变化与DNA损伤之间的关系.方法:将H.pylori ACTC43504(Cag A+,Vac A+)感染正常胃黏膜系GES-1细胞,分别通过活细胞工作站观察细胞内ROS变化和多功能酶标仪定量检测细胞内ROS含量.采用凯基彗星实验法(单细胞凝胶电泳)检测DNA损伤.结果:ROS的水平和H.pylori的作用浓度呈正比,至MOI 300∶1时ROS荧光最强.不同浓度的N-乙酰半胱氨酸(N-acety-L-cysteine,NAC)均可抑制H.pylori感染所引起的ROS的生成.H.pylori可导致DNA损伤,NAC预处理后,GES-1细胞的尾长、彗星长、尾矩及Olive尾矩数值均较H.pylori组有明显下降趋势.结论:H.pylori作用GES-1细胞后,可使ROS生成增多,损伤DNA.抑制ROS的生成可减轻H.pylori感染导致的DNA损伤.

AIM： To explore the relationship between the change of reactive oxygen species （ROS） and DNA damage caused by Helicobacter pylori （H. pylori） infection in gastric epithelial cells. METHODS： H. pylori ACTC43504 （CagA^＋, VacA^＋） infected GES-1 cells were used in this study. Live cell imaging system was used to observe the change of intracellular ROS, and a microplate reader was used to detect intracellular ROS level. Single cell gel electrophoresis comet assay was used to detect DNA damage. RESULTS： ROS level was proportional to H. pylori concentration, and the ROS level was the highest when the MOI of H. pylori was 300∶1. Various concentrations of N-acety-L-cysteine （NAC） could significantly inhibit the generation of ROS caused by H. pylori infection. H. pylori could cause DNA damage. After NAC pretreatment, the values of tail length, comet length, tail moment, and Olive tail moment had a clear downward trend compared with the H. pylori group. CONCLUSION： H. pylori infection in GES-1 cells increases intracellular ROS level and results in DNA damage. Inhibition of the generation of ROS could reduce DNA damage.