鼠巨细胞病毒感染诱导小鼠精子凋亡及线粒体调控机制研究

目的 研究鼠巨细胞病毒(MCMV)感染对小鼠精子凋亡的影响,探讨MCMV感染诱导小鼠精子凋亡的线粒体调控机制.方法 建立小鼠睾丸MCMV急性感染模型(n=15),以正常小鼠作为对照(n=15),采用流式细胞术(FCM)与激光扫描共聚焦显微术(LCSM)对不同感染时段的小鼠附睾尾部成熟精子进行凋亡与线粒体膜电位的检测,同时应用电镜观察不同感染时段的精子线粒体超微结构的改变.结果 MCMV感染第2天起精子凋亡率开始升高,第4天达最高值(39.3±1.0)%,随后逐渐下降(F=362.822,P＜0.05).而感染第1天的精子线粒体膜电位增加至74.0±1.4,第2天开始下降至63.0±2.2,第4天降至最低40.2±2.3,随后缓慢回升(F=32.257,P＜0.05).MCMV感染可引起精子线粒体超微结构的损伤,以感染第2～6天为重.结论 生殖器官MCMV急性感染可诱导附睾尾部成熟精子的凋亡;精子线粒体主动参与并调控了精子的凋亡过程.

Apoptosis of sperm induced by murine cytomegalovirus infection and its mechanism regulated by sperm mitochondria: experiment with mice

Objective To stuay the effects of murine cytomegalovirus(MCMV)infection on mature sperm apoptosis in mice,and to explore the mechanism of MCMV-induced apoptosis regulated by mitochondria.Methods MCMV was inoculated into the testes of 15 BALB/c mice to establish acute MCMV infection models and 15 mice were used as controls.1,2,4,6,and 9 days after the infection 3 mice from each group were killed.Flow cytometry was used to observe the apoptosis of sperms.Laser scanning confocal microscopy was performed to examine the mitochondrial membrane potential(△ψm)of sperm.The mitochondria ultrastructure of sperm was observed under electron microscope.Reslllts The sperm apoptotic rate began to increase from day 2 after inoculation(D2 PI),peaked to the level of(39.3±1.0)％ compared withthat of the control group on D4 PI,andthenfell.Off(F=362.822,P<0.05).The △ψm of sperm began to increase on D1 PI at the level of(74.0±1.4),began to decrease on D2 PI (63.0±2.2)],dropped to the minimum on I)4 PI(40.2±2.3)],then ascended slowly again(F=32.257,P<0.05).The mitochondria uhrastructure of sperm showed damage after MCMV infection that Was especially severe from D2 PI to D6 PI.Conclusion MCMV acute infection in reproductive organ induces apoptosis of mature sperm in the cauda epididymidis. Sperm mitochondria participate in and regulate initiatively the apoptosis of sperm.