先天性巨细胞病毒(CMV)感染致胎脑发育畸形，机制尚不清楚。高表达脑发育重要调控因子Sox2的神经前体细胞(NPC)是胎脑发育的基础和CMV最敏感靶标。我们基于NPC库建立了CMV感染的细胞模型，发现感染和病毒蛋白IE1均下调Sox2，提示其可致胎脑发育畸形。本项目拟在NPC中筛选调控Sox2的IE1靶标分子；建立鼠胎脑CMV感染模型，检测胎脑感染及发育情况，鉴定感染对NPC、Sox2水平、脑皮质结构及各层标志分子的影响，明确CMV感染下调Sox2对胎脑发育的作用。比较CMV野生/IE1缺失毒株感染鼠胎脑时Sox2水平和胎脑发育的差异，明确IE1对胎脑发育的影响。经胎脑电转表达IE1、突变体，比较其下调 Sox2和对胎脑发育的差异，揭示IE1下调Sox2所需的结构域和机制。检测临床样本CMV感染、胎脑发育生物标记分子水平，评估感染和胎脑损伤风险，验证实验研究结果，为产前确诊和干预提供依据。

Congenital cytomegalovirus (CMV) infection is the leading cause of fetal brain development disorders in newborns, the mechanism is unclear. Sox2 controls stem cell fate and is essential for fetal brain development. The deficiency or mutation in Sox2 causes fetal brain maldevelopment in clinic. Sox2 is highly expressed in neural progenitor cells (NPC). NPC is the foundation of fetal brain development and the most susceptible target for congenital CMV infection. We have isolated NPC from fetal brain of 115 cases, thus built a NPC bank. The CMV infected NPC model was established. Our following work found that CMV infection induced NPC abnormal differentiation, further discovered CMV infection or IE1 protein downregulated Sox2. These evidences indicate that Sox2 downregulation by IE1 plays an important role in fetal brain maldevelopment..The aim of this project is to elucidate how CMV infection and IE1 protein downregulate Sox2 which in turn causes fetal brain maldevelopment, so that to bridge the gap between CMV infection and fetal brain maldevelopment. To fulfil this aim, the major tasks include:.1) Identify IE1 targets in NPC. Express IE1 in NPC, screen IE1 targets by comparison proteomics; verify the levels of the selected IE1 targets in NPC expressing IE1; identify IE1 targets responsible for Sox2 regulation; investigate the interaction between IE1 and its targets..2) Establishing a CMV infected murine fetal brain model to demonstrate the effect of IE1 protein on Sox2 and fetal brain development. First, infect murine fetal brain with GFP expressing CMV (CMV-GFP), track distribution of GFP in the brain, examine the brain size and structure; detect CMV infection, IE1 and Sox2, and distribution of markers of different cortex layers. Then, infect with CMV-GFP-wt, -dlIE1 and -rvIE1 viruses, compare fetal brain development and the infections of the viruses; figure out the differences in infection, Sox2 level and fetal brain development..3) Establishing an IE1 expressing murine fetal brain model to demonstrate the effect of IE1 on Sox2 downregulation and fetal brain development. First, express wide type IE1(IE1-wt) in lateral subventricular zone by directional in utero electroporation, detect IE1 and Sox2 in NPC, examine development of fetal brain as described above. Then express IE1 mutants, detect the expressions and the according levels of Sox2 in NPC, compare the fetal brain development. Find out the differences in Sox2 levels and fetal brain development induced by IE1-wt and mutants, detect the selected IE1 targets, figure out the essential functional domain of IE1 required for Sox2 regulation..4) Clinical study: Collect congenital HCMV infected tissue samples, detect viral infection, brain structure, IE1, Sox2 and the selected IE1 targets in NPC. Collect amniotic fluids from the congenital HCMV infected cases, determine HCMV infection, screen the biomarkers to evaluate the risk for brain damage.