NLRP3炎症小体在甲型流感病毒和MRSA致小鼠肺炎早期的作用差异

The different role of NLRP3 inflammasome in the early stage of pneumonia caused by influenza A virus and MRSA in mice

目的探讨NLRP3炎症小体在甲型流感病毒H1N1(甲流病毒H1N1)及耐甲氧西林金黄色葡萄球菌(MRSA)所致肺炎早期的作用。方法分别以甲流病毒H1N1/FM1株与MRSA滴鼻感染C57BL/6小鼠各5只,引起甲流病毒肺炎与MRSA肺炎,感染24 h后,观察肺组织病理,荧光定量PCR检测各组小鼠肺组织NLRP3蛋白、IL-1β的mRNA表达强度,蛋白免疫印迹法检测小鼠肺组织NLRP3蛋白相对表达量,ELISA检测小鼠血清IL-1β的浓度。结果NLRP3蛋白的mRNA表达水平及蛋白表达水平各组间比较差异有统计意义(F mRNA=38.782和F蛋白=1325.64,P均为0.000),IL-1β的mRNA表达水平及血清浓度各组间比较差异有统计学意义(F mRNA=1253.97和F血清=41.974,P均为0.000)。H1N1组NLRP3蛋白的mRNA表达水平及蛋白表达水平均高于空白对照组(P均<0.05),IL-1β的mRNA表达水平及血清浓度均高于空白对照组(P均<0.01)。MRSA组NLRP3蛋白的mRNA表达水平高于空白对照组(P<0.05),蛋白表达水平与空白对照组比较差异无统计学意义(P>0.05),MRSA组IL-1β的mRNA表达及血清浓度均高于空白对照组(P均<0.01)。H1N1组NLRP3蛋白的mRNA表达水平及蛋白表达水平均高于MRSA组(P均<0.05),但MRSA组IL-1β的mRNA表达水平及血清浓度均明显高于H1N1组(P均<0.01),与肺组织病理变化相一致。结论在甲流病毒性肺炎及MRSA肺炎早期,NLRP3炎症小体介导甲流病毒引起的炎症反应,但并没有在MRSA引起的剧烈炎症反应中起重要作用。

To evaluate and compare the role of NLRP3 inflammasome between pneumonia caused by influenza A virus H1N1(IAV H1N1)and methicillin-resistant Staphylococcus aureus(MRSA)in mice.Pneumonia caused by intranasal inoculation with IAV H1N1 FM1 strain and MRSA in mice was established respectively.After infected for 24 h,fluorescence quantitative PCR was applied to detect the expression of NLRP3 and IL-1βmRNA in lung,Western blot was used to detect the protein of NLRP3 in lung,and the concentration of IL-1βin serum was measured by enzyme linked immunosorbent assay(ELISA).The transcription and translation levels of NLRP3 were significantly different among control,H1N1 and MRSA groups(F=38.782 and 1325.64,P=0.000).The transcription level of IL-1 in lung and concentration of IL-1 in serum were also significantly different among control,H1N1 and MRSA groups(F=1253.97 and 41.974,respectively,P=0.000 and 0.000 respectively).In the IAV H1N1 group,the expression of NLRP3 m RNA and NLRP3 proteins were significantly higher than those in the control group and MRSA group(all P<0.05).The expression of IL-1βmRNA and concentration of IL-1βin H1N1 group were significantly higher than those in the control group(P<0.01).The expression of NLRP3 mRNA in MRSA group was higher than control group(P<0.05),while,the expression of NLRP3 protein between MRSA group and control group wasn’t noted.In the MRSA group,the expression of IL-1βmRNA and concentration of IL-1βin serum were significantly higher than those in the control group and H1N1 group(all P<0.01).It suggests that NLRP3 inflammasome involve in pneumonia induced by influenza A virus H1N1,but it do not play an improtant role in the intense inflammatory response caused by MRSA in early stage.