应用基因表达差异谱鉴定新神经干细胞标志物

Identification of a novel neural stem cell marker using gene expression profiling

目的应用基因芯片技术发现并鉴定新的神经干细胞(NSC)分子标志物。方法应用基因芯片技术,比较8.5 d胎龄的胎鼠神经管细胞和体节细胞基因表达差异谱,筛选神经管细胞高表达的特异性基因,并通过半定量RT-PCR和原位杂交的方法,验证差异性基因的表达,从而确定神经干细胞的特异性分子标志物。结果经过基因芯片筛选,选择11个神经干细胞特异性高表达的基因,通过半定量RT-PCR验证这11个基因在不同组织的表达,发现只有Celsr1、Celsr2、Sema5b和Rhbdl3 4个基因是特异性表达在富含干细胞的脑室下增殖区(SVZ)及胎鼠海马区;进一步通过原位杂交验证四种基因在神经干细胞球和胎鼠脑矢状切片的表达,发现Celsr2在神经干细胞球和神经管均表达,说明Celsr2不仅表达在神经干细胞,还表达在其分化的祖细胞中,而Sema5b特异性的表达在神经管。结论 Sema5b可作为神经干细胞新的分子标志物。

Objective The identification of markers for the isolation of neural stem cell（NSC） is essential for studies of their biology and therapeutic applications. Methods Microarray analysis was used to compared the gene expression profile of different position of embryo to identify functionally coordinated alterations in gene expression associated with neural progenitor proliferation. Results 11 differentially expressed genes were upregulated in NEP cells relative to SMT cells. 4 molecules（Celsr1,Celsr2,Sema5 b and Rhbdl3） were enriched in the germinal neuroepitheliu screened by RT-PCR. In situ hybridizations showed that Celsr1, Celsr2 and Rhbdl3 were expressed specifically in the neurospheres. Only Sema5 b were expressed specifically in neural epithelium in the tissue sections from developing mouse at embryonic day 13. Conclusion Sema5 b is a novel neural stem cell marker.