乳鼠海马神经干细胞向神经细胞分化过程中Notch1 mRNA的表达

Notch1 mRNA expression during the differentiation of neural stem cells isolated from hippocampal of rats toward neurons

目的建立神经干细胞(NSC)向神经细胞分化的培养体系,探讨Notch1mRNA在NSC分化过程中的表达情况。方法无菌分离新生(24h)SD大鼠海马NSC,体外扩增、纯化,并诱导NSC向神经细胞分化。细胞诱导前、后,采用免疫荧光化学法鉴定巢蛋白(Nestin)和神经元特异性烯醇酶(NSE)的表达;用逆转录-PCR检测NSC中Notch1mRNA的表达情况。结果从乳鼠海马分离的NSC在体外能克隆增殖,并表达Nestin。诱导分化后,细胞NSE阳性表达;Notch1mRNA在NSC诱导分化前、后均有表达。与诱导前相比,NSC诱导分化后各阶段Notch1mRNA表达水平均明显降低(P<0.05),而NSC分化各阶段Notch1mRNA表达的差异无统计学意义(P>0.05)。结论诱导NSC向神经细胞分化能抑制其Notch1mRNA的表达,低水平的Notch信号可能有利于神经细胞的分化。

Objective To establish culture system to induce neural stem cells（NSC） differentiation toward neurons and explore the expression of Notchl mRNA in NSC during its differentiation. Methods NSC in hippocampal of newborn（24 h） SD rats were isolated sterilely,amplified and purified in vitro, and were induced to differentiate toward neurons. Before and after cellular induc- tion,immunofluorescence was employed to identify the expression of Nestin and neuron specific enolase （NSE）, reverse transcrip- tion-PCR was utilized to detect the expression of Notchl mRNA in NSC. Results NSC isolated from hippocampal of newborn rats showed clonal proliferation in vitro, and positive Nestin expression. After induced differentiation, the differentiated cells demonstra- ted positive NSE expression,and Notch1 mRNA expression was found in NSC both before and after induced differentiation. Com- pared to induction before,levels of Notch1 mRNA expression in NSC during different stages of differentiation after induction were significantly reduced（P〈0.05）,and the difference of Notch1 mRNA expression among these stages of differentiation was not sta- tistically significant（P〉0.05）. Conclusion Induction of NSC differentiation toward neurons can inhibit its Notchl mRNA expres sion,and lower level of Notch signaling may be beneficial for differentiation of neurons.