摘要
目的人巨细胞病毒（human cytomegalovirus,HCMV）感染可抑制神经干细胞（neural stem cell,NSC）的增殖和分化,Notch信号对NSC的增殖和分化具有重要的调控功能。文中研究HCMV感染对人NSC向星形胶质细胞分化过程中Notch信号相关分子Notch1~3、Jagged（JAG）1、delta-like（DLL）1及早老素（presenilin,PS）1表达的影响。方法体外分离培养海马NSC,并诱导其向星形胶质细胞分化。同时以感染复数（multiplicity of infection,MOI）为5的HCMV AD169株感染NSC,分别在感染后0、1、3、5、7 d收获细胞,用实时RT-PCR法检测细胞内Notch1-3及其受体JAG1、DLL1的转录水平,Westernblot法检测Notch1细胞内段（Notch 1 intracellular domain,NICD）含量的变化。结果未分化状态的NSC含有大量Notch1NICD,Notch1-3、JAG1、DLL1mRNA呈高表达。诱导分化1d后,Notch各受体、配体mRNA表达均显著下降,3 d后表达回升,至第7天显著升高且可检出大量激活的NICD。HCMV感染组细胞在诱导分化1 d后Notch相关受体、配体mRNA水平亦明显下降,与对照组相比Notch1、Notch2和DLL1的表达更少。在以后各个时间点Notch相关受体、配体mRNA水平均低于对照组。PS1的表达仅在1 d时低于对照组。病毒感染7 d后,细胞内NICD含量明显低于对照组。结论HCMV感染可抑制Notch相关受体、配体的表达与活化,Notch信号异常表达参与HCMV感染所致NSC分化和增殖异常。
Objective Human cytomegalovirus（HCMV） infection can inhibit the proliferation and differentiation of neural stem cells（NSCs）,and Notch signaling has an important role in their regulation.The purpose of this study was to investigate the effect of HCMV infection on the expressions of Notch-1-3,JAG1,DLL1 and PS1 in human hippocampal NSCs during their differentiation into astrocytes.Methods Hippocampal NSCs were isolated and grown in vitro,and induced to differentiate into astrocytes.At the beginning of differentiation,the NSCs were infected with HCMV AD169（MOI=5） and collected at 0,1,3,5 and 7 days after the infection.The expressions of Notch-1-3,JAG1 and DLL1 and PS1 mRNA were detected by real time RT-PCR,and the changes in the Notch-1 intracellular domain（NICD） measured by Western blot.Results Notch-1 NICD,Notch-1-3,JAG1 and DLL1 mRNA were highly expressed in the undifferentiated NSCs at 0 day,decreased significantly at 24 hours after differentiation,and increased at 3 days,up to the peak at 7 days with widely activated NICD.In the HCMV infection group,Notch receptor and ligand mRNA expressions were decreased significantly at 24 hours,particularly Notch-1,Notch-2 and DLL1,and remained lower at the other time points as compared with the control.The expression of PS1 was lower only at 1 day and that of NICD significantly lower at 7 days in the HCMV than in the control group.Conclusion HCMV infection can inhibit the expression and activation of Notch receptors and ligands,and Notch signaling abnormality is involved in the mechanism of HCMV infection-triggered abnormal differentiation and proliferation of NSCs.
出处
《医学研究生学报》
CAS
2010年第10期1013-1019,共7页
Journal of Medical Postgraduates
基金
国家自然科学基金(30770105)
青岛市科技计划项目(08-1-3-30-jch)
泰山学者建设工程专项经费资助
