幽门螺杆菌感染蒙古沙鼠胃组织NLRP3炎症小体相关因子和自噬相关蛋白表达分析

Expression analysis of NLRP3 inflammasome and mitophagy-related indexes in gastric tissue of Mongolian gerbil infected by Helicobacter pylori

目的探究幽门螺杆菌(Helicobacter pylori,Hp)感染对蒙古沙鼠胃组织中NLRP3炎症小体相关因子和自噬相关蛋白表达的影响。方法采用Hp国际标准株11637灌胃处理蒙古沙鼠,隔天一次,共5次,以相同体积无菌脑心浸液肉汤灌胃的沙鼠作为对照组。于感染第3、6、12和24个月后处死沙鼠,取胃黏膜组织并切片,HE染色后作病理学检查;免疫组织化学染色观察Hp定植;试剂盒法检测胃组织NLRP3炎症小体及其相关因子IL-18、IL-β和自噬相关蛋白P62、LC3的表达。结果Hp感染蒙古沙鼠胃组织检测到Hp的定植,HE染色检查显示不同时间感染组沙鼠胃黏膜均出现糜烂黏膜下层组织水肿、黏膜局部浅表糜烂和淋巴浆细胞浸润等不同程度的慢性胃炎病理改变,感染24月部分区域出现非典型增生甚至癌变。对照组沙鼠均无Hp定植及组织学病变。与未感染对照组比较,Hp感染蒙古沙鼠胃组织中NLRP3、IL-18、IL-1β和LC3、P62的表达水平均显著升高(均P<0.05);其中NLRP3、IL-18、LC3表达3到12个月随着Hp感染时间的延长呈升趋势,12到24个月呈下降趋势。IL-1β表达无显著变化,P62呈持续上升趋势。结论蒙古沙鼠感染Hp后可出现与人极相似的胃粘膜病理组织学改变,并促进蒙古沙鼠胃组织NLRP3炎症小体活化和自噬水平升高,这可能是Hp引起胃部病理变化的其中一个原因。

Objective The purpose of this study was to see how Helicobacter pylori(Hp)infection affected the expression of NLRP3infammasome-related factors and autophagy-related proteins in Mongolian gerbil gastric tissues.Methods Mongolian gerbils were gavaged with Hp international standard strain 11637 once every other day for five times,while control gerbils were gavaged with the same volume of sterile brain heart infusion broth.The gerbils were sacrificed 3,6,12,and 24 months after infection,and the gastric mucosa tissues were sliced and stained with HE for pathological examination,immunohistochemical staining was performed to observe Hp colonization,and reagent kit assays were used to detect the expression of gastric NLRP3 infammasome associated factors NLRP3,IL-18,IL-1βand autophagyassociated proteins P62 and LC3.Results HE staining revealed that the gastric mucosa of the Hp infected gerbils at different times presented chronic gastritis pathological changes of varying degrees,including edema of the submucosal tissue,local superficial erosion of the mucosa,and lymphoplasmic cell infiltration.Atypical hyperplasia or even cancer appeared in some areas of gerbils infected with Hp for 24 months.The gerbils in the control group lacked histological lesions and Hp colonization.The expression levels of NLRP3,IL-18,IL-1β,LC3 and P62 in the gastric tissues of Hpinfected Mongolian gerbils were significantly increased compared to the uninfected control group(all P<0.05).The expression of NLRP3,IL-18,and LC3 increased gradually during 3-12 months as the Hp infection was prolonged,but decreased gradually during 12-24 months.The expression of IL-1βshowed no significant change,whereas P62 showed an increasing trend.Conclusion Mongolian gerbils infected with Hp can exhibit pathological histological changes in the gastric mucosa that are very similar to those seen in humans,as well as promote NLRP3 infammasome activation and elevated levels of autophagy in Mongolian gerbil gastric tissues,which may be one of the reasons for Hp-induced pathological changes in the stomach.