产肠毒素大肠杆菌K88对BALB/c小鼠肝脏炎症反应、程序性坏死和焦亡信号通路关键基因表达的影响

Effects of Enterotoxigenic Escherichia coli K88 on Expression of Key Genes in Liver Inflammatory Response,Necroptosis and Pyroptosis Signaling Pathways in Liver of BALB/c Mice

本试验旨在研究产肠毒素大肠杆菌(ETEC)K88对BALB/c小鼠肝脏炎症反应、程序性坏死和焦亡信号通路关键基因表达的影响。试验选取25只9周龄、体重(17±1)g的雌性BALB/c小鼠,随机分为5个组,每组5只,每只小鼠腹腔注射1×10^(7) CFU/mL ETEC K88菌液0.2 mL;分别于注射ETEC K880、12、24、36和48 h时屠宰小鼠,取肝脏组织测定炎性因子、程序性坏死和焦亡信号通路关键基因mRNA的表达。结果表明:1)与0 h相比,小鼠肝脏中炎性因子肿瘤坏死因子-α(TNF-α)的mRNA相对表达量在24、36和48 h时显著升高(P<0.05),白细胞介素-1β(IL-1β)的mRNA相对表达量在12和36 h时显著升高(P<0.05),白细胞介素-6(IL-6)的mRNA相对表达量在36和48 h时显著升高(P<0.05);2)与0 h相比,小鼠肝脏中受体相互作用蛋白激酶1(RIPK1)的mRNA相对表达量在12 h时显著升高(P<0.05),受体相互作用蛋白激酶3(RIPK3)的mRNA相对表达量在36 h时显著升高(P<0.05),混合谱系激酶结构域样假激酶(MLKL)的mRNA相对表达量在12、36和48 h时显著升高(P<0.05);3)与0 h相比,小鼠肝脏中核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)的mRNA相对表达量在36 h时显著升高(P<0.05),凋亡相关斑点样蛋白(ASC)的mRNA相对表达量在12、36和48 h时显著升高(P<0.05),半胱氨酸天冬氨酸蛋白酶-1(Caspase-1)的mRNA相对表达量在24和36 h时显著升高(P<0.05),消皮素D(GSDMD)的mRNA相对表达量在12、24和36 h时显著升高(P<0.05),白细胞介素-18(IL-18)的mRNA相对表达量在24 h时显著升高(P<0.05)。综上所述,ETEC K88感染引起小鼠肝脏炎症反应,激活了小鼠肝脏程序性坏死和焦亡信号通路。

This experiment was conducted to investigate the effects of enterotoxigenic Escherichia coli(ETEC)K88 on the expression of key genes in inflammatory response,necroptosis and pyroptosis signaling pathways in liver of BALB/c mice.Twenty-five nine-week-old female BALB/c mice weighing(17±1)g were randomly divided into 5 groups with 5 mice in each group.Each mouse was intraperitoneally injected with 0.2 mL 1×10^(7) CFU/mL ETEC K88 bacterial solution.Mice were slaughtered at 0,12,24,36 and 48 h after ETEC K88 injection,and liver tissues were taken to determine the mRNA expressions of key genes in inflammatory factors,necroptosis and pyroptosis signaling pathways.The results showed as follows:1)compared with 0 h,the inflammatory factor tumor necrosis factor-α(TNF-α)mRNA relative expression level in liver of mice was significantly increased at 24,36 and 48 h(P<0.05),the interleukin-1β(IL-1β)mRNA relative expression level was significantly increased at 12 and 36 h(P<0.05),and the interleukin-6(IL-6)mRNA relative expression level was significantly increased at 36 and 48 h(P<0.05).2)Compared with 0 h,the receptor-interacting protein kinase 1(RIPK1)mRNA relative expression level in liver of mice was significantly increased at 12 h(P<0.05),the receptor-interacting protein kinase 3(RIPK3)mRNA relative expression level was significantly increased at 36 h(P<0.05),and the mixed lineage kinase domain like pseudokinase(MLKL)mRNA relative expression level was significantly increased at 12,36 and 48 h(P<0.05).3)Compared with 0 h,the nucleotide binding oligomeric domain-like receptor protein 3(NLRP3)mRNA relative expression level of in liver of mice was significantly increased at 36 h(P<0.05),the apoptosis-associated speck-like protein(ASC)mRNA relative expression level was significantly increased at 12,36 and 48 h(P<0.05),the cysteine-aspartic protease-1(Caspase-1)mRNA relative expression level was significantly increased at 24 and 36 h(P<0.05),the gasdermin D(GSDMD)mRNA relative expression level was significantly increased at 12,24 and 36 h(P<0.05),and the interleukin-18(IL-18)mRNA relative expression level was significantly increased at 24 h(P<0.05).In conclusion,ETEC K88 infection can cause liver inflammation in mice,and activate the signaling pathways of necroptosis and pyroptosis in liver of mice.