中文摘要：

目的：观察鼠巨细胞病毒（MCMV）感染对体外培养神经干细胞（NSCs）细胞周期进程和cyclins表达的影响,探讨MCMV感染致脑发育异常的机制。方法：本实验体外分离、培养和鉴定BABL/C胎鼠NSCs,以感染复数（MOI）为5,1和0.1的MCMVsmith毒株感染NSCs并于感染后1,2,3,4,5,6d收集细胞,采用Cyclin/DNA双参数流式细胞术检测感染细胞cyclinA,cyclinB1,cyclinD1,cyclinE的表达和细胞周期时相的动态变化,观察MC-MV对感染NSCs细胞周期进程的影响。结果：体外分离培养的NSCs呈球样生长,神经干细胞特异性标记Nestin表达阳性,并可进一步分化为GFAP阳性的星形胶质细胞和NF-200阳性的神经元;各感染组cyclinA,cyclinB1,cy-clinD1和cyclinE的表达均上调,其中MOI=0.1表达逐渐上升,在第6d达峰值,MOI=1组表达高峰在第4d,MOI=5组表达高峰在第3d;感染组G0/G1期细胞比率减少,S期和G2/M期细胞比率增加,其变化趋势与cyclins的表达基本一致,并随MOI的增加变化越明显。结论：Cyclin/DNA多参数流式细胞术可用于NSCs细胞周期的分析;MCMV可通过上调cyclinA,cyclinB1,cyclinD1,cyclinE的表达来影响NSCs细胞周期进程,并与MOI存在一定量效依赖关系;MCMV感染可诱导NSCs从G0/G1期进入S期,出现S期和G2/M期偏移和阻滞,影响NSCs细胞周期进程,这可能是CMV抑制NSCs增殖并导致先天性脑发育异常的重要机制之一。

英文摘要：

Objective：The influence of MCMV infection on cell cycle progression and cyclins expression of neural stem cells（NSCs）in vitro were investigated by Cyclins/DNA multiparameter flow cytometry for studying the machanisms of brain abnormalities caused by congenital cytomegalovirus infection.Methods：NSCs were separated from fetal BALB/C mouse and cultured and identified in vitro.The NSCs were infected by MCMV with multiplicity of infection（MOI）equaled to 5,1 and 0.1,respectively and were collected at 1 d,2 d,3 d,4 d,5 d and 6 d post infection.The cyclinA,cyclinB1,cyclinD1,cyclinE and dynamic changes of cell cycle of infected NSCs were detected by Cyclins/DNA multiparameter flow cytometry.Results：NSCs isolated from embryonic mouse brains proliferated to form neurosphere and strongly expressed Nestin,a specific marker of NSCs and had the capacity to differentiate into NF-200 positive neurons or GFAP positive astrocytes.The expression of cyclinA,cyclinB1,cyclinD1 and cyclinE of infected NSCs upregulated.The expression of cyclins of the infected NSCs with MOI=0.1 gradually increased and reached to the peak at 6d.The peak expression of cyclins of the infected NSCs with MOI=1 and 5 appeared at 4 d and 3 d post infection,respectively.The cell rate of G0/G1 phase decreased and the rate of S phase and G2/M phase increased.The infected NSCs migrated to and blocked at S phase and G2/M and its changes were more obvious following the MOI increased.Conclusion：Cyclins/DNA multiparameter flow cytometry is reasonable and practical for analysis the cell cycle of NSCs.MCMV could influence the cell cycle processes of NSCs by upregulating the expression of cyclinA,cyclinB1,cyclinD1 and cyclinE,and the effect showed certain dose dependence relationship with MOI.MCMV could induce NSCs to enter into S phase from G0/G1 phase and the cell cyle of NSCs migrated to and blocked at S phase and G2/M.The influence of MCMV on the cell cycle processes of NSCs maybe one of the mechanism of CMV inhibit the proliferation of NSCs and lead t