呼吸道合胞病毒诱导A549细胞凋亡与NF-κB信号通路有关

Respiratory syncytial virus induces the apoptosis of A549 associated with NF-κB signaling pathway activation

目的探讨呼吸道合胞病毒(RSV)诱导肿瘤细胞凋亡机制,为临床肿瘤治疗提供新方向。方法 RSV以感染复数(MOI)3感染人肺Ⅱ型腺上皮癌细胞(A549)及人肺成纤维细胞(IMR-90)细胞,在感染后2、4、8、24、36、48和72 h等不同时间点,光学显微镜观察细胞形态,MTT法检测细胞存活率,空斑实验测定细胞内病毒滴度,Western blot法检测caspase-3,8,9、细胞色素C(CytC)和NF-κB蛋白表达。结果 RSV感染A549及IMR-90细胞后,A549细胞存活率较IMR-90低,细胞内病毒滴度较IMR-90高(P<0.05),细胞呈现明显凋亡改变。Caspase-3,8,9和CytC呈时间依赖性增强,以caspase-9表达为主。A549细胞内NF-κB表达8 h内先增高并达高峰,24 h开始下降,36 h表达明显下调(P<0.01)。结论 RSV可通过内源性及外源性途径引起A549细胞凋亡,以内源性途径为主,NF-κB在此过程中发挥一定作用。

Objective To investigate the apoptosis mechanism of respiratory syncytial virus（RSV） and to provide a novel clinical therapy through the change of NF-κB after RSV infected A549 and IMR-90 cell. Methods RSV with the multiplicity of infection （MOI） 3 infecting A549 and IMR-90 cell, cell morphological change was observed using optical microscope, cell viability was detected with MTF, RSV viral titer was detected by empty spot test. Caspase- 3, 8, 9,cytochrome-c and NF-κB protein expression were detected with Western blot method. Results RSV infec- tion A549 and IMR-90 cell, A549 cell survival was lower than IMR-90, intraeellular virus titer was higher than IMR-90（P 〈 0. 05）. Cell showed obviously apoptosis change. Caspase-3, 8, 9 and cytochrome-c increased in a time-dependent manner. Caspase-9 expressions were observed. In early phase. RSV infection NF-KB was activa- ted. NF-KB expression was down-regulated after 36 h RSV infection （ P 〈 0. 01 ）. Conclusions RSV can cause A549 cell apoptosis through the endogenous and exogenous way. The endogenous way is primary. NF-κB plays a certain role in the process.