肺部菌群干预对PM_(2.5)诱导肉鸡肺部炎症损伤的影响  

Effects of pulmonary microbiota intervention on PM_(2.5)-induced lung inflammatory injury in broilers

作　　者：周子琳 李盛 沈丹 李春梅[1] ZHOU Zilin;LI Sheng;SHEN Dan;LI Chunmei(Research Center for Livestock Environmental Control and Smart Production,College of Animal Science and Technology,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学动物科技学院家畜环境控制与智慧生产研究中心,江苏南京210095

出　　处：《南京农业大学学报》2024年第2期323-333,共11页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(32072781)。

摘　　要：[目的]本试验旨在研究肺部菌群对PM_(2.5)诱导肉鸡肺部炎症损伤的影响,并利用盲肠肠球菌处理肺泡上皮细胞,探究肺部盲肠肠球菌在PM_(2.5)诱发肺部炎症损伤中的作用。[方法]选取45只19日龄雄性AA肉鸡随机分为3组:对照组、PM_(2.5)组(PM)和肺部菌群干预组(ABX-PM)。从21日龄开始,ABX-PM组肉鸡气管滴注抗生素消减肺部菌群,每天滴注1次,连续滴注3 d,其他2组肉鸡气管滴注无菌生理盐水。在24和26日龄时,分别向PM组和ABX-PM组肉鸡气管滴注PM_(2.5)悬浮液诱导肺部炎症损伤,对照组肉鸡气管滴注无菌生理盐水。在最后一次气管滴注PM_(2.5)24 h后对肉鸡进行称重,并采集肺组织、支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)和血清样品。检测BALF和血清内炎症因子水平、肺组织内紧密连接(tight junctions,TJ)蛋白基因表达水平以及肠球菌属和盲肠肠球菌相对含量,并进行盲肠肠球菌相对含量与炎症因子水平的相关性分析。另外,体外培养A549细胞并分为2组,对照组加入不含盲肠肠球菌的DMEM/F12培养基,处理组加入含有1×10^(4) CFU·mL^(-1)盲肠肠球菌的DMEM/F12培养基。处理6 h后,检测2组细胞炎症因子、TJ及细胞凋亡相关基因表达水平。[结果]与对照组相比,PM组肉鸡BALF和血清IL-8水平显著升高,而ABX-PM组差异不显著;与对照组相比,PM组肉鸡肺组织occludin及claudin-1 mRNA表达水平显著降低,claudin-5 mRNA表达水平显著升高,而ABX-PM组差异不显著;PM组肉鸡肺部肠球菌属和盲肠肠球菌的相对含量显著高于对照组和ABX-PM组;肺部盲肠肠球菌相对含量与BALF内IL-1β、IL-6、IL-8水平和血清内IL-1β水平呈显著正相关关系。体外细胞试验结果显示,与对照组相比,处理组A549细胞tnf-α、il-1β、il-6及il-8 mRNA表达水平显著升高,il-10 mRNA表达水平显著降低;处理组A549细胞zo-1及claudin-1 mRNA表达水平显著降低;处理组A549细胞bax/bcl-2 m[Objectives]This study aimed to investigate the effect of the pulmonary microbiota on PM_(2.5)-induced lung inflammatory injury in broilers and to explore the role of Enterococcus cecorum on PM_(2.5)-induced lung inflammatory injury using E.cecorum-treated alveolar epithelial cells.[Methods]A total of fourty-five male AA broilers(19-day-old)were randomly divided into three groups:the control group,the PM_(2.5) group(PM),and the pulmonary microbiota-intervened group(ABX-PM).From 21 days of age,broilers in the ABX-PM group were intratracheally instilled with antibiotics once a day for three days.Meanwhile,broilers in the other two groups were simultaneously instilled with sterile saline.At 24 and 26 days of age,broilers in the PM and ABX-PM groups were intratracheally instilled with PM_(2.5) suspension to induce lung inflammatory injury,and broilers in the control group were simultaneously instilled with sterile saline.Twenty-four hours after the last intratracheal instillation of PM_(2.5),we weighed the broilers and collected lung tissue,bronchoalveolar lavage fluid(BALF),and serum samples.We measured the levels of inflammatory factors in BALF and serum.Besides,we measured the gene expression levels of tight junctions(TJ)protein,the relative content of Enterococcus spp.and E.cecorum in the lung tissue,and the correlation between the relative content of E.cecorum and inflammatory factor levels.In addition,type Ⅱ alveolar epithelial cells(A549)were cultured and divided into two groups.The control group was treated with DMEM/F12 medium without E.cecorum,while the E.cecorum treatment group was treated with DMEM/F12 medium containing 1×10^(4) CFU·mL^(-1) E.cecorum.We compared the gene expression levels of inflammatory factors,TJ,and apoptosis between the two groups after 6 h of treatment.[Results]The levels of IL-8 in BALF and serum,as well as the mRNA expression levels of occludin and claudin-1 in lung tissue,were significantly higher in the PM group than those in the control group.The claudin-5 mRNA expression le

关 键 词：肺部菌群 肺部炎症 肉鸡 盲肠肠球菌 肺泡上皮细胞 

分 类 号：S852[农业科学—基础兽医学]