PM2.5通过激活Nlrp3炎性小体诱导小鼠肺炎症反应  

PM_(2.5) induces lung inflammatory response of mice by activation of Nlrp3 inflammasome

作　　者：仝国辉[1] 李煜[1,2] 郑德生 滕克强 何立伟[1] 刘建中[1] 刘晶晶[1] 李子南[1] 陶晶[1] 张鹏[1] 巩政[4] 马娜娜[4] 谭壮生[1] 尤育洲[1] 李国君[1,2] 宁钧宇[1,2] 

机构地区：[1]北京市疾病预防控制中心/北京市预防医学研究中心,食品中毒诊断溯源技术北京市重点实验室,北京100013 [2]首都医科大学公共卫生学院 [3]密云疾病预防控制中心 [4]北京大学医学部

出　　处：《毒理学杂志》2017年第3期176-181,共6页Journal of Toxicology

基　　金：北京市自然科学基金(7152024);北京市科技计划(Z121100000312007)

摘　　要：目的本文比较了PM_(2.5)单次染毒和3次染毒后对小鼠血液学、细胞因子表达的影响,并对炎性作用机制进行了初步研究。方法用气管滴注法对BALB/c雄性小鼠染毒,PM_(2.5)剂量分别为对照组、0.5、2.0和5.0 mg/kg·bw。染毒结束后进行血细胞计数,用Elisa法测定肺组织匀浆白细胞介素(interleukin,IL)-1β、IL-4和干扰素γ(interferon-γ,IFN-γ)含量,用RT-q PCR检测肺组织NLRP3(NACHT、LRR and PYD domains-containing protein 3)炎性小体相关基因的mRNA表达,HE染色法进行肺组织病理学检测。结果 PM_(2.5)染毒1次后,各剂量对小鼠血液中白细胞计数无显著影响,5.0 mg/kg·bw剂量组的中性粒细胞百分比较对照组显著升高(P<0.01)。PM_(2.5)3次染毒后,3个剂量组均可使中性粒细胞百分比显著升高(P<0.01),而淋巴和单核细胞百分比显著降低(P<0.05或P<0.01)。PM_(2.5)单次染毒和3次染毒后,2.0和5.0 mg/kg·bw剂量组均可引起小鼠肺组织IL-1β表达量的升高,5.0 mg/kg·bw剂量组可使IL-4和IFN-γ表达量下降(P<0.05或P<0.01)。此外,染毒3次后,2 mg/kg·bw剂量组比染毒1次同等剂量组白细胞计数和IL-1β表达量均降低(P<0.05)。PM_(2.5)染毒3次的肺样本5.0 mg/kg·bw组与对照组比较,Nlrp3的表达量则明显升高(P<0.05),但胱天蛋白酶1(Caspase-1)表达量未显著升高。组织病理学可见5.0 mg/kg·bw组与对照组比较,气管周边淋巴滤泡增大,肺泡内可见巨噬细胞。结论 PM_(2.5)能引起小鼠的炎症反应,反映在血中中性粒细胞百分比升高而淋巴细胞比例下降,且有较好的剂量-效应和时间-效应关系。同时PM_(2.5)染毒可使IL-1β升高,但IL-4及IFN-γ在染毒1次和染毒3次均降低。PM_(2.5)可能通过活化NLRP3炎性小体和IL-1β受体途径参加炎症反应。Objective The effect of PM2.5 on hematology and cytokines expression was compared after single and three times exposure in mice. Its inflammatory mechanisms were also studied. Methods BALB/c male mice were exposed to PM2.5 using tracheal instillation with doses of control,0. 5,2. 0 and 5. 0 mg/kg·bw respectively. After exposure,blood cells were counted. IL-1 beta,IL-4 andγ-IFN level in supernatant of lung tissue homogenate were assayed using Elisa method. NLRP3 inflammasome-related genes expression was tested by RT-q PCR method. Microscopic structure changes of lung were observed. Result White blood cells（ WBC） were not affected after single exposure of PM2.5 ,while neutrophil percentage of 5. 0 mg/kg·bw group was significantly increased compared with the control group（ P〈0. 01）. After PM2.5 three times exposure,neutrophil percentage were increased significantly（ P〈0. 01）,while lymphatic and monocyte percentage decreased significantly（ P〈0. 05,or P〈0. 01） in three exposed groups compared with the control group. After PM2.5 single and repeatedly exposure,IL-1 beta level in the lung tissue was increased in 2. 0 and 5. 0 mg/kg·bw dose groups,while IL-4 and IFN-gamma level were reduced in 5. 0 mg/kg·bw dose group（ P〈0. 05 or P〈0. 01）. In addition,after PM2.5 three times exposure,white blood cells count and IL-1 beta level were all decreased in 2. 0 mg/kg·bw dose group compared with single time exposure（ P〈0. 05）. After three times exposure,the expression of Nlrp3 was significantly higher than the control（ P〈0. 05）,but Caspase1 expression was not changed. In5. 0 mg/kg·bw dose group compared with the control after PM2.5 three times exposure,the trachea peripheral lymphoid follicles were increased and macrophages could be seen in lung alveoli. Conclusion PM2.5 can cause the inflammatory response of mice,reflected in the increase of neutrophil percentage and reduction of lymphocyte percentage in blood,with better dose effect and time effect relationship. PM2.5 exposure c

关 键 词：PM2.5 Nlrp3炎性小体 炎症反应 

分 类 号：R99[医药卫生—毒理学]