幽门螺杆菌感染对AOM/DSS诱导的小鼠炎症相关性结直肠癌的影响及免疫机制  

The effects and immunologic mechanisms of Helicobacter pylori infection on AOM/DSS induced colitis-associated cancer in mice

作　　者：李罗娜 刘芸[1] 张鸿晨[1] 吴婷 戴芸[1] 王蔚虹[1] Li Luona;Liu Yun;Zhang Hongchen;Wu Ting;Dai Yun;Wang Weihong(Department of Gastroenterology,Peking University First Hospital,Beijing 100034,China)

机构地区：[1]北京大学第一医院消化内科,北京100034

出　　处：《中华医学杂志》2020年第34期2689-2695,共7页National Medical Journal of China

基　　金：北京市自然科学基金(7182165)。

摘　　要：目的探讨幽门螺杆菌(H.pylori)感染对氧化偶氮甲烷(AOM)联合葡聚糖硫酸钠(DSS)诱导的小鼠炎症相关性结直肠癌的影响及相关机制。方法C57BL/6J小鼠60只,随机分为正常对照组(Control组,n=9)、H.pylori感染组(Hp组,n=9)、AOM/DSS诱导组(AOM/DSS组,n=21)和H.pylori感染合并AOM/DSS诱导组(Hp+AOM/DSS组,n=21),分别在AOM/DSS造模第19、45和85天处死小鼠。苏木精-伊红染色检测结肠组织病理学变化,流式细胞术检测结肠组织中辅助性T细胞17(Th17)和调节性T细胞(Treg)比例,实时定量聚合酶链反应和酶联免疫吸附法检测白细胞介素(IL)-10、IL-17A、维A酸相关孤独受体(ROR)γt和叉头/翼状转录因子(Foxp3)等Th17和Treg细胞相关因子的表达水平。结果Control组和Hp组小鼠结肠黏膜结构完整;Hp+AOM/DSS组小鼠结肠炎症(第19天)和异型增生(第45天)阶段的病理评分以及(第85天)结肠肿瘤负荷均低于AOM/DSS组(均P<0.05)。在造模第85天,Hp+AOM/DSS组小鼠结肠组织中CD3+CD4+IL-17A+Th17和CD3+CD4+IL-17A+Foxp3+Treg细胞比例(1.88±0.17比2.07±0.89,1.06±0.13比1.89±0.23)及RORγt和IL-17A的mRNA表达水平(1.08±0.59比2.35±1.35,2.96±0.92比7.78±4.57)均低于AOM/DSS组(均P<0.05),而CD3+CD4+CD25+Foxp3+Treg和CD3+CD4+IL-10+Foxp3+Treg细胞比例(20.60±3.39比15.63±2.71,2.94±0.52比2.14±0.47)及Foxp3和IL-10的mRNA表达水平[17.59(13.77,24.87)比6.27(4.41,13.36),3.52(1.59,5.99)比1.17(1.15,2.75)]均高于AOM/DSS组(均P<0.05)。结论胃内H.pylori感染减缓AOM/DSS诱导的小鼠结肠炎症-异型增生-肿瘤进程,伴随结肠Th17细胞比例减少和Treg细胞比例增加。Objective To investigate the effects and potential mechanisms of Helicobacter pylori(H.pylori)infection on azoxymethane(AOM)/dextran sulfate sulphate(DSS)induced colitis-associated cancer(CAC)in mice.Methods A total of 60 specific pathogen free C57BL/6J mice were randomly divided into four groups:normal control group(control group,n=9),H.pylori-infected group(Hp group,n=9),AOM/DSS-treated group(AOM/DSS group,n=21)and AOM/DSS-treated with H.pylori infection group(Hp+AOM/DSS group,n=21).Mice were sacrificed on day19,45 or 85 after AOM/DSS challenge.Histopathological changes in colonic tissues were determined by hematoxylin and eosin staining.Flow cytometry analysis was performed to determine T helper cells 17(Th17)and regulatory T cells(Treg)in colonic lamina propria.The expression levels of Th17-and Treg-associated cytokines and transcription factors[interleukin(IL)-10,IL-17A,retinoic acid receptor-related orphan receptorγt(RORγt)and forkhead box P3(Foxp3)]were determined by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay.Results There were no histopathological changes in colonic tissues of mice in control group and Hp group.H.pylori colonization reduced the histopathological scores at the stages of colitis(day 19)and dysplasia(day 45),and also decreased tumor load(day 85)in mice treated with AOM/DSS(all P<0.05).Compared with AOM/DSS group,the percentages of CD3+CD4+IL-17A+Th17 and CD3+CD4+IL-17A+Foxp3+Treg cells(1.88±0.17 vs 2.07±0.89,1.06±0.13 vs 1.89±0.23)and the expression levels of RORγt and IL-17A(1.08±0.59 vs 2.35±1.35,2.96±0.92 vs 7.78±4.57)were decreased in colonic tissues of Hp+AOM/DSS group(all P<0.05).The percentages of CD3+CD4+CD25+Foxp3+Treg and CD3+CD4+IL-10+Foxp3+Treg cells(20.60±3.39 vs 15.63±2.71,2.94±0.52 vs 2.14±0.47)and the expression levels of Foxp3 and IL-10[17.59(13.77,24.87)vs 6.27(4.41,13.36),3.52(1.59,5.99)vs 1.17(1.15,2.75)]in colonic tissues were higher(all P<0.05)in mice of Hp+AOM/DSS group compared with AOM/DSS group on day 85.Con

关 键 词：幽门螺杆菌 辅助性T细胞17 调节性T细胞 炎症相关性结直肠癌 

分 类 号：R735.34[医药卫生—肿瘤]