磁刺激对大鼠神经干细胞CDK5基因表达的影响

目的：研究脉冲磁刺激对离体神经干细胞内CDK5蛋白和基因表达的影响。方法：神经干细胞克隆在体外培养传代后，置于0．5Hz，1．44T的磁刺激，每天1次，30个脉冲；作用3d后诱导分化，用CDK5的特异性引物对诱导分化后0、48和72h的神经干细胞进行RT—PCR分析，并用Western—Blot法检测神经干细胞中CDK5蛋白的表达。结果：通过RT-PCR可见，对照组CDK5在分化前已有表达，随着分化的进展，CDK5的表达逐渐增强，至48h达高峰，然后逐渐减低；磁刺激组与对照组呈现相同的趋势，但在不同时间点CDK5的表达均高于对照组。Western-Blot显示神经干细胞中CDK5蛋白的表达与RT-PCR的结果一致。结论：0．5Hz，1．44T磁刺激能够促进神经干细胞分化时CDK5基因和蛋白表达，这可能是磁刺激促进神经干细胞向神经元方向分化的机制之一。

Effects of Magnetic Stimulation on CDK5 Gene Expression of Rat Neural Stem Cells

Objective: To investigate the effects of magnetic stimulation(MS) on CDK5 gene expression in rat neural stem cells.Methods: Cultured neural stem cell clones after passaging several times in vitro were exposed to magnetic stimulation(0.5 Hz,1.44 Tesla),30 pulses per day for 3 days and then differentiation induced.The sham-exposure controls were correspondingly established.By using RT-PCR assay with specific primer of CDK5 the expression of CDK5 gene was detected at 0,48 and 72 h post differentiation.The expression of CDK5 protein was tested by using Western blotting at the same time. Results: RT-PCR analysis demonstrated that CDK5 mRNA was expressed in neural stem cells before differentiation in control group.With time going on the level of CDK5 mRNA was gradually increased,peaked at 48 h post-differentiation and then gradually decreased.Compared with control group,CDK5 mRNA expression in MS group were significantly higher at 48 and 72h.The expression of CDK5 protein was consistent with that of CDK5 mRNA expression.Conclusion: MS could promote the CDK5 mRNA and protein expression,which might be one of the mechanisms by which MS promote the differentiation of rat neural stem cells into neuron-like cells in vitro.