Toll样受体4在高氧暴露对小胶质细胞功能影响中的作用  

Role of Toll-like receptor 4 in hyperoxia-exposed microglia injury

作　　者：刘杨[1] 蒋朴[2] 徐颖[1] 

机构地区：[1]重庆医科大学附属儿童医院麻醉科,儿童发育疾病研究省部共建教育部重点实验室,儿科学重庆市重点实验室,重庆市儿童发育重大疾病诊治与预防国际科技合作基地,重庆400014 [2]重庆医科大学基础医学院法医学教研室,重庆400016

出　　处：《细胞与分子免疫学杂志》2012年第11期1162-1165,共4页Chinese Journal of Cellular and Molecular Immunology

基　　金：中国博士后基金资助(20090450790)

摘　　要：目的:探讨Toll样受体4(TLR4)在高浓度氧暴露对小胶质细胞功能的影响。方法:体外培养N9小胶质细胞(TLR4野生型)和EOC20小胶质细胞(TLR4敲除型),给予950 mL/L高氧分别暴露不同时段,建立高氧损伤细胞模型。RT-PCR检测N9细胞TLR4 mRNA表达时序变化;Westernblot法检测N9细胞TLR4蛋白表达;通过抗氧化剂N-乙酰半胱氨(N-acetyl-L-cysteine,NAC)干预,观测950 mL/L高氧暴露后2 h及6 h的N9和EOC20小胶质细胞内的活性氧(ROS)含量、NF-κB核转录活性及细胞上清中TNF-α含量。结果:高浓度氧暴露的N9小胶质细胞TLR4的表达上调,并呈一定时间依赖性,同时ROS活性,核转录因子NF-κB活性,TNF-α表达明显增高(P<0.05)。抗氧化剂NAC干预后,ROS活性明显降低,核转录因子NF-κB活性明显降低,细胞上清内TNF-α水平亦显著下调(P<0.05)。与N9小胶质细胞相比,高氧暴露后各时间点EOC20细胞的ROS活性,核转录因子NF-κB活性以及TNF-α表达均较低(P<0.05)。结论:TLR4参与调控高氧导致的小胶质细胞ROS的形成及炎症因子的释放。AIM： To explore the role of Toll-like receptor 4 （TLR4） in the injury of microglia exposed to hyperoxia. METHODS： N9 microglia （TLR4 wild type） and EOC20 microglia （TLR4 knock-out type） were exposed to 950 mL/L high oxygen respectively for different time periods to establish the high oxygen cell injury model. Expression of TLR4 mRNA and protein levels were detected by RT-PCR and Western blotting, respectively. After intervention with the antioxidant NAC （ N-acetyI-L-cysteine, N-acetyl half pathway of ammonia）, we detected the activity of reactive oxygen species （ ROS）, NF-KB and the expression of TNF- a in cellular supernatant of N9 and EOC20 microglia exposed to hyperoxia for 2, 6 h. RESULTS： Expression of TLR4 mRNA in N9 microglia exposed to hyperoxia increased in a time-dependent manner, meanwhile, activity of ROS, NF-KB and expression of TNF-a in microglia exposed to hyperoxia significantly increased （ P 〈 0. 05）, while decreased （P 〈 0.05） after intervention with the antioxidant NAC. The activity of ROS, NF-KB and the expression of TNF-a were lower in EOC20 microglia than in N9 microglia after exposed to hyperoxia for different time periods （P 〈 0.05）. CON- CLUSION： TLR4 involves in the regulation of forming ROSand the release of inflammatory markers on microglia after exposed to hyperoxia.

关 键 词：高浓度氧 小胶质细胞 TOLL样受体4 活性氧 

分 类 号：R392.12[医药卫生—免疫学] R392-33[医药卫生—基础医学]