旋毛虫感染小鼠后TNF-α诱导肺细胞凋亡的观察

Experimental observation of TNF-α-induced pulmonary apoptosis in the mice infected with Trichinella spiralis

为探究TNF-α在旋毛虫致小鼠肺损伤发生过程中的致病作用及信号传导途径,应用半定量RT-PCR法检测感染前、后不同时期小鼠肺组织中TNF-α及细胞凋亡与抗凋亡基因mRNA的表达量,并应用TUNEL法对肺细胞凋亡形态进行观察。结果显示,旋毛虫感染后第4天,TNF-αmRNA的相对表达量由感染前的0.74上升到1.19,肺细胞凋亡增加,凋亡指数为2.57%;第14天出现峰值1.33,此时凋亡指数为21.42%,肺细胞凋亡明显(P<0.05),35d后表达量逐渐下降至1.11,此时凋亡指数为14.74%。TNFR1、FADD、Caspase8、Caspase3、TRAF2、RIP和NF-κB的相对表达量与TNF-α变化趋势相似。结果表明,TNF-α诱导肺细胞凋亡严重程度与旋毛虫生活史的不同阶段相关。

To explore the pathogenic role and signal transduction pathways of TNF-α-induced lung injury of the mice infected with Trichinella spiralis, the mRNA expression levels of TNF-α gene,the apoptosis genes and the anti-apoptosis genes both in the lungs without injury and in the injured lungs were monitored using semi-quantitative RT-PCR. The morphologic features of the cells undergoing apoptosis were observed using TUNEL at different time points during Trichinella spiralis infection. In result,the relative expression level of TNF-α was from 0.74（before infection）to 1.19（on day 4 post-infection）,and the lung cells of apoptosis increased. On day 14 post-infection,it reached peak（1.33）,then decreased to 1.11 on day 35 post-infection. Apoptosis index,meanwhile,increased from 2.57% to 21.42%（P〈0.05）,and then decreased to 14.74%.The relative level of TNFR1,FADD,Caspase8,Caspase3,TRAF2,RIP and NF-κB showed a similar tendency to TNF-α＇s.TNF-α induced severity of lung cell apoptosis,which is related to the different stages of Trichinella life.