幽门螺杆菌VacA蛋白体外诱导胃上皮AGS细胞内HMGB1的表达

HMGB1 expression in gastric epithelial AGS cells in vitro induced by vacuolating cytotoxin of Helicobacter pylori

目的探讨幽门螺杆菌(Hp)感染的胃上皮AGS细胞内高迁移率族蛋白B1(high mobility group box 1,HMGB1)的表达。方法 Hp11638(CagA+,VacA+)和Hp11638突变株(Hp11638M,CagA+,VacA-)的提取液与AGS细胞共同温育后,收集细胞及培养上清液。裂解AGS细胞,western blot分析AGS细胞内HMGB1的表达,ELISA法检测培养上清液中HMGB1的水平。结果 Hp11638提取液刺激AGS细胞后HMGB1表达量为(123.33±25.2)μg/mL,明显高于Hp11638M提取液刺激后的(46.67±7.23)μg/mL(q=8.49,P<0.01)。Hp11638和Hp11638M提取液刺激的AGS细胞培养上清液中HMGB1的水平分别为(115.59±16.62)和(48.32±6.30)ng/mL,差异有统计学意义(q=12.25,P<0.01)。结论在胃炎发生、发展过程中,VacA蛋白是刺激细胞中HMGB1高表达的主要因子。

Objective To explore the expression of high mobility group box 1（HMGB1） in gastric epithelial AGS cells infected by Helicobacter pylori（HP）.Methods Both the extracts of Hp11638 strain,which was positively expressed cytotoxin-associated protein（CagA） and vacuolating cytotoxin（VacA）,and Hp11638 mutant strain（Hp11638M,CagA＋,VacA-） were incubated with AGS cells respectively.The AGS cells and the supernatant were collected.The AGS cells were splitted to analyze the expression of HMGB1 by western blotting,and the level of HMGB1 in the supernatant was measured by ELISA.Results The content of HMGB1 in AGS cells infected by extracts of Hp11638 was（123.3±25.2） μg/mL,which was significantly higher than that of Hp11638M（46.67±7.23） μg/mL,q=8.49,P0.01.The level of HMGB1 in the culture supernatant infected by the extracts of Hp11638 was（115.59±16.62） ng/mL which was significantly higher than that of Hp11638M（48.32±6.30） ng/mL,q=12.25,P0.01.Conclusions During the development and advance of gastritis,vacuolating cytotoxin may be the main factor for stimulating AGS cells to highly express HMGB1 protein.