MNNG亚慢性暴露致大鼠胃损伤及炎性反应机制研究  

Mechanism of gastric injury and inflammatory response induced by sub-chronic exposure to MNNG in rats

作　　者：张永欣 曾勇 王婷 李益桐 马超 李响丽 王俊玲[1] 李成云[1] ZHANG Yong-xin;ZENG Yong;WANG Ting;LI Yi-tong;MA Chao;LI Xiang-li;WANG Jun-ling;LI Cheng-yun(Department of Toxicology,College of Public Health,Lanzhou University,Lanzhou Gansu 730000,China)

机构地区：[1]兰州大学公共卫生学院卫生毒理学研究所,甘肃兰州730000

出　　处：《毒理学杂志》2023年第1期12-17,30,共7页Journal of Toxicology

基　　金：兰州大学中央高校基本科研业务费专项资金(lzujbky-2022-25);甘肃省卫生健康行业科研计划项目(GSWSKY2022-24)。

摘　　要：目的 观察N-亚硝基化合物-甲基硝基亚硝基胍(MNNG)亚慢性暴露对大鼠胃黏膜组织炎性损伤的影响。方法 75只SPF级雄性Wistar大鼠(体重80~100 g)随机分为生理盐水对照组、MNNG染毒组(0.08、0.12、0.16和0.20 mg/kg),每组15只。对照组大鼠采用等量生理盐水灌胃,实验组大鼠以0.08、0.12、0.16和0.20 mg/kg MNNG灌胃染毒,同时自由饮用含30μg/ml MNNG的水,持续染毒13周。苏木素-伊红(HE)染色观察大鼠胃组织结构改变,Western blot技术及免疫组化实验检测大鼠胃组织凋亡、炎性相关蛋白及胃癌肿瘤相关Wnt信号通路关键蛋白的表达变化。结果 大鼠胃组织切片结果显示,MNNG亚慢性暴露可引起大鼠胃黏膜糜烂、脱落、坏死,胃黏膜下出血,部分胃组织切片中可见大量炎性细胞浸润。与对照组大鼠相比,MNNG亚慢性暴露大鼠胃组织中凋亡相关蛋白Bcl-2呈明显降低趋势,而Bax,半胱氨酸天冬氨酸蛋白酶3(Caspase-3)蛋白表达量呈上升,差异有统计学意义(P<0.05)。与对照组相比,实验组大鼠Wnt信号通路关键蛋白β-catenin, p-GSK-3β,CK1,Axin1和TCF7的表达水均升高,差异具有统计学意义(P<0.05);免疫组化结果显示,与对照组相比,MNNG亚慢性暴露大鼠胃组织Wnt信号通路关键蛋白β-catenin, p-GSK-3β表达水平升高,数据差异具有统计学意义(P<0.05)。结论 MNNG亚慢性暴露可引起大鼠胃黏膜组织结构发生炎性损伤,并引诱发胃组织凋亡、炎性相关蛋白及胃癌肿瘤相关Wnt信号通路关键蛋白的表达变化,本研究可为MNNG亚慢性暴露致大鼠胃损伤及炎性反应机制探索提供参考。Objective To observe the effects of subchronic exposure to N-methyl-N′-nitro-N-nitrosoguanidine(MNNG) on inflammation damage of gastric mucosal tissues in rats. Methods Seventy-five SPF-grade male Wistar rats(80~100 g) were randomly divided into saline control group and MNNG-stained group(0.08, 0.12, 0.16 and 0.20 mg/kg), 15 rats in each group. The rats in the control group were gavaged with equal amounts of saline, while the rats in the experimental group were gavaged with 0.08, 0.12, 0.16 and 0.20 mg/kg MNNG and drank water containing 30 μg/ml of MNNG, sustained oral perfusion for 13 weeks. The expression levels of apoptosis, inflammation-related proteins and key proteins of the Wnt signaling pathway in the gastric tissues of rats were measured by Western blot technique and immunohistochemistry. Results The result showed that subchronic exposure to MNNG caused gastric mucosal erosion, detachment and necrosis, and submucosal hemorrhage in rats, and a large number of inflammatory cells were found in some gastric tissue sections. Compared with the control group, the expression of apoptosis-related protein Bcl-2 in the gastric tissues of MNNG subchronic-exposed rats was significantly lower, while the expression levels of Bax and Caspase-3 protein were significantly higher(P<0.05). Compared with the control group, the expression levels of Wnt signaling pathway key proteins β-catenin, p-GSK-3β, CK1, Axin1 and TCF7 in the experimental group were significantly were significantly increased, and the difference was statistically significant(P<0.05). Immunohistochemical result showed that the expression levels of Wnt signal pathway key protein β-catenin and p-GSK-3β were significantly higher in the gastric tissues of MNNG subchronic exposed rats compared with the control group(P<0.05). Conclusion Subchronic exposure to MNNG induced inflammatory damage to rat gastric mucosa and induced changes in the expression of apoptosis-related proteins, inflammation-related proteins and key proteins of the Wnt signaling pathway

关 键 词：MNNG 亚慢性暴露 胃组织结构 炎性反应机制 

分 类 号：R114[医药卫生—卫生毒理学] R735.2[医药卫生—公共卫生与预防医学] R99