T细胞转录因子-4在大鼠脑缺血再灌注海马齿状回神经干细胞中的表达

Expression of T cell transcription factor-4 in hippocampal neural stem cells after cerebral ischemia reperfusion injury in rats

目的:检测T细胞转录因子-4(Tcf-4)在大鼠脑缺血再灌注海马组织神经干细胞中的表达及其变化。探讨影响神经干细胞早期增殖分化的分子调控机制。方法:采用大脑中动脉栓塞(MCAO)制作大鼠脑缺血再灌注模型。用免疫组织化学SP法及RT-PCR法检测海马神经干细胞BrdU、Tcf-4中的表达。结果:随着脑缺血再灌注第3日齿状回神经元BrdU阳性细胞明显增多,第7日达高峰,然后逐渐减少。Tcf-4 mRNA反应产物随脑缺血再灌注时间延长逐渐增多,第21日表达最强,以后表达逐渐减少。结论:Tcf-4时间依赖性表达与神经干细胞增殖分化进程相吻合,说明其在神经干细胞晚期分化中起重要调控作用。

Objective： To investigate the expression of T cell transcription factor-4 （Tcf-4） in hippocampus after cerebral ischemia and reperfusion in rats, and to explore the molecular mechanism of the proliferation and differentiation of neural stem cells. Methods： A novel model of cerebral ischemia and reperfusion was induced by middle cerebral artery occlussion （MCAO） in rats; expression of BrdU and Tcf-4 mRNA in hippocampal neural stem cells was detected with SP immunohistochemical method and RT-PCR. Results： Neural stem cells were activated after cerebral ischemia. After three days, BrdU positive cells in the hippocampus were obviously increased. On the seventh day, BrdU positive cells were more than those at any time.The expression of Tcf-4 mRNA had not similar trend with the expression of BrdU. Conclusion： The expression of Tcf-4 mRNA corresponds with the proliferation and differentiation of neural stem cells, suggesting that Tcf-4 may play an important role in regulating the differentiation of the neural stem cell.