孕早期人巨细胞病毒感染对仔鼠神经行为的影响

Influence of Human Cytomegalovirus Infection during First Trimester on Neurobehavior of Mice

目的探讨孕早期人巨细胞病毒(HCMV)感染对仔鼠神经行为的影响。方法将8周龄昆明小鼠按雌雄2:1合笼配对,将受精小鼠随机分为实验组与对照组,于妊娠第4天分别腹腔内注射1×10-6半数组织培养感染量HCMV悬液0.5mL和等量的人胚成纤维细胞上清液,孕第20天时每组随机选取3只作剖宫产,取胎鼠脑组织进行光镜和电镜检查;定性检测仔鼠及孕鼠血清HC-MV DNA;在仔鼠6～7周时进行Morris水迷宫和LashleyⅢ水迷宫检测。结果与对照组比较,光镜下实验组仔鼠脑组织可见神经细胞变性坏死,细胞核消失,部分细胞呈巨细胞变;电镜下发现神经元细胞明显肿胀,胞质中可见类球形病毒颗粒;实验组7只仔鼠血清中检测出特异性HCMV pp65片段。在Morris水迷宫测试中,实验组仔鼠第7天潜伏期为(30.21±12.74)s,对照组为(11.87±3.62)s,二组比较有显著性差异(P<0.05);游泳速度实验组为(19.10±1.90)cm/s,对照组为(23.21±1.02)cm/s,二组比较有显著性差异(P<0.05);在LashleyⅢ水迷宫测试中,第5天实验组潜伏期为(45.88±18.24)s,与对照组[(125.56±9.82)s]比较有显著性差异(P<0.01);错误次数实验组与对照组比较,亦存在显著性差异(P<0.05)。结论孕早期HCMV感染可使仔鼠学习记忆能力、运动能力显著下降。

Objective To explore the neurobehavioral change of mice from dams with human cytomegalovirus（HCMV） infection during first trimester. Methods Eight - week - old fertilized female Kunming mice were randomly divided into infected group and control group. On the 4＇h gestation day mice in infected group were injected intraperitoneally with 0.5 mL HCMV （ 1 x 10 ^-6 50 percent of tissue cultured infective dose）, and those in control group were injected intraperitoneally with 0.5 mL supernatant of cultured human fibroblast. Caesarean birth operation was performed on 3 randomly chosen fertilized mice before delivery. Fetuses were observed and their brain tissue were collected and analyzed under light and electron microscope separately. PCR test was used to determine HCMV pp65 antigen of offspring＇s sera. Neurobehavioral test such as Morris Water Maze and Lashley m Water Maze were performed on offspring mice of 6 - 7 weeks old. Results Compared with control group, the pathological changes such as degeneration, necrosis, and nucleus disappearance of nerve cells and giant cells were found in offspring＇s brain of mice in infected group under light microscope. Under electron microscope, swelling of nerve cells and spherical virus particle in the cytoplasm were found in the brain of mice in infected group. HCMV pp65 antigen was detected in 7 offspring mouse＇s serum in infected group. Offspring＇s swimming time and speed were（30.21 ± 12.74） s and（ 19.10 ± 1.90） cm/s in infected group,while those in control group were （11.87 ± 3.62） s and （23.21 ± 1.02） cm/s by Morris Water Maze test, there were significantly differences between 2 groups （Pa 〈 0.05 ）. Offspring＇s average swimming time in infected group [ （45.88 ± 18.24 ） s ] was also longer than that in control group [ （ 25.56 ± 9.82 ） s ] by Lashley m Watery Ⅲ Maze test （ P 〈 0.05 ）. Compared with control group, the errors in infected group were significantly increased by Lashley Ⅲ Water Maze test （P 〈 0.05 ）. Conclusion Congenital HCMV infection in mouse may cause a variety of disabilities, such as learning disabilities and motion disabilities.