MLKL对金黄色葡萄球菌感染所致小鼠肝脏和肾脏损伤的调控作用  

MLKL-mediated regulation against Staphylococcus aureus infection-induced liver and kidney damage in mice

作　　者：刘博[1] 巩志国 赵佳敏 于琢雅 刘谕泽 白云洁 王超 秦少杰 吴敬泽 包文慧 张双翼[1] LIU Bo;GONG Zhiguo;ZHAO Jiamin;YU Zhuoya;LIU Yuze;BAI Yunjie;WANG Chao;QIN Shaojie;WU Jingze;BAO Wenhui;ZHANG Shuangyi(College of Veterinary Medicine,Inner Mongolia Agricultural University,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学兽医学院,内蒙古呼和浩特010018

出　　处：《中国兽医学报》2024年第4期670-676,共7页Chinese Journal of Veterinary Science

基　　金：国家自然科学基金资助项目(32202879,32160854);内蒙古自治区高等学校科学研究重点资助项目(NJZZ23035);内蒙古农业大学优秀博士人才引进科研启动资助项目(NDYB2021-19)。

摘　　要：运用ELISA、免疫荧光法、苏木素-伊红染色法以及流式细胞术分析了金黄色葡萄球菌(Staphylococcus aureus,S.aureus)分别感染MLKL基因敲除(MLKL^(-/-))和C57BL/6J小鼠后肝脏和肾脏中促炎性细胞因子(TNF-α和IL-1β)和抗炎因子(IL-10)的分泌、组织脏器的损伤水平、血液中中性粒细胞募集和小鼠存活情况。结果显示,在S.aureus感染MLKL^(-/-)小鼠肝脏和肾脏中TNF-α的分泌水平显著高于C57BL/6J小鼠肝脏和肾脏中TNF-α的分泌水平(P<0.001)。此外,S.aureus感染C57BL/6J小鼠肝脏和肾脏中,IL-10的分泌水平显著高于MLKL^(-/-)小鼠(P<0.05)。免疫荧光检测结果显示,与C57BL/6J小鼠相比,S.aureus感染MLKL^(-/-)小鼠后肝脏和肾脏中组织损伤标志物HMGB1蛋白表达处于较高水平(P<0.01)。病理切片结果显示,使用S.aureus感染后,MLKL^(-/-)小鼠肝脏和肾脏损伤程度显著高于C57BL/6J小鼠。S.aureus感染后,MLKL^(-/-)小鼠血液中CD11b和Gr-1双阳性的比例显著高于C57BL/6J小鼠血液中的比例(P<0.01)。使用高低剂量S.aureus分别感染小鼠后,发现MLKL^(-/-)小鼠的生存率低于C57BL/6J小鼠。结果表明,MLKL对S.aureus感染诱导的宿主细胞因子分泌具有一定的下调作用,进而发挥对宿主脏器损伤的保护作用,降低小鼠的病死率。In this study,we analyzed the secretion of pro-inflammatory cytokines(TNF-αand IL-1β)and anti-inflammatory cytokine(IL-10),as well as the level of tissue organ damage,recruitment of neutrophils in blood of S.aureus-infected MLKL knockout(MLKL^(-/-))and C57BL/6J mice by ELISA,immunofluorescence,hematoxylin-eosin staining and flow cytometry,respectively.The results showed that the levels of TNF-αsecretion were significantly higher in the liver and kidneys of S.aureus-infected MLKL^(-/-)mice compared to C57BL/6Jmice(P<0.001).Moreover,the secretion level of IL-10in the liver and kidneys of S.aureus-infected C57BL/6Jmice was significantly higher than in MLKL^(-/-)mice(P<0.05).Immunofluorescence staining revealed that the expression of the tissue damage marker HMGB1protein in the liver and kidneys was higher in S.aureus-infected MLKL^(-/-)mice compared to C57BL/6Jmice(P<0.01).Histopathological analysis showed that the extent of liver and kidney damage in S.aureus-infected MLKL^(-/-)mice was significantly higher than in C57BL/6Jmice.After S.aureus infection,the proportion of CD11band Gr-1double positive cells in the blood of MLKL^(-/-)mice was significantly higher than in C57BL/6J mice(P<0.01).The mice infected with different doses of S.aureus,MLKL^(-/-)mice had a lower survival rate compared to C57BL/6Jmice.These results indicate that MLKL has a certain downregulatory effect on host cytokine secretion induced by S.aureus infection,thereby exerting aprotective role in host organ damage and reducing mouse mortality.

关 键 词：S.aureus 混合系列蛋白激酶样结构域 坏死性凋亡 脏器损伤 细胞因子 小鼠 

分 类 号：S852.61[农业科学—基础兽医学] R535[农业科学—兽医学]