肠道病毒感染致神经损伤小鼠脑组织NOD样受体蛋白3的表达

Expression of NLRP3 in nerve injury mice caused by enterovirus

目的:探讨NOD样受体蛋白3(NLRP3)在肠道病毒(EV)感染导致的神经损伤中的作用。方法:30只BALB/c小鼠分为对照组、肠道病毒(EV)71组和柯萨奇病毒A组2型(CVA2)组,每组10只。EV71组和CVA2组小鼠分别经腹腔注射EV71或经肌内注射CVA2,观察临床症状和生存情况。感染后第7天,采用HE和尼氏染色观察脑组织病理变化,采用免疫荧光对NLRP3和EV71/CVA2进行共定位观察。使用qRT-PCR法检测小鼠脑组织NLRP3、Caspase-1、IL-1β、IL-18 mRNA的表达,Western blot法检测NLRP3、Caspase-1和IL-1β蛋白的表达。结果:EV71和CVA2感染后小鼠出现明显的嗜睡、昏迷、共济失调、肢体麻痹等神经系统受累症状。与对照组比较,EV71组和CVA2组小鼠脑组织出现炎细胞浸润、血管袖套、胶质细胞聚集和神经元退行性病变。EV71组和CVA2组小鼠脑组织病毒抗原蛋白与NLRP3存在共定位。与对照组比较,EV71组和CVA2组小鼠脑组织中NLRP3、Caspase-1、IL-1β、IL-18 mRNA的表达升高,NLRP3、Caspase-1、IL-1β蛋白的表达升高(P<0.05)。结论:NLRP3炎性小体活化可能参与EV71或CVA2感染所致的神经系统损伤。

Aim:To investigate the role of NOD-like receptor protein 3(NLRP3)inflammasome in the nerve injury caused by enterovirus(EV)infection.Methods:Thirty BALB/c mice were allocated into control group,EV71 group and coxsackievirus A2(CVA2)group,10 mice in each group.EV71 group was inoculated with EV71 via intraperitoneal route,CVA2 group was inoculated with CVA2 via intramuscular route,and the clinical score and survival were recorded.At 7 days post infection,pathological changes of brain tissues in infected mice and control mice were observed by HE staining and Nissl staining,NLRP3 and EV71/CVA2 antigens were observed by immunofluorescence staining.The expression levels of NLRP3,Caspase-1,IL-1βand IL-18 mRNA were detected by qRT-PCR,and the expression levels of NLRP3,Caspase-1 and IL-1βproteins were detected by Western blot.Results:EV71-infected or CVA2-infected mice displayed distinct symptoms of narcolepsy,coma,ataxia,limb paralysis caused by nervous system injury,and inflammatory cell infiltration,vascular cuffs,aggregation of glial and neuronal degeneration were observed in the brain tissue.Immunofluorescent staining revealed the co-localization of NLRP3 and antigens of EV71 or CVA2 in brain tissue.Compared with the control mice,the expression levels of NLRP3,Caspase-1,IL-1βand IL-18 mRNA in brain tissue of EV71 or CVA2 infected mice were increased,and the protein expression levels of NLRP3,Caspase-1 and IL-1βwere significantly increased(P<0.05).Conclusion:NLRP3 inflammasome activation may be involved in the nervous system injury caused by EV71 or CVA2 infection.