移动电话射频电磁场对大鼠神经细胞微管结合蛋白2基因表达的影响

Effect of 1.8 GHz radiofrequency electromagnetic fields on the expression of micrombule associated protein 2 in rat neurons

目的了解1．8 GHz移动电话射频电磁场(RF EMF)对大鼠神经细胞基因表达的影响,筛选射频电磁场反应基因。方法体外原代培养新生SD大鼠皮层和海马神经细胞至第13天,将细胞随机分为实验组(辐照组)和对照组(假辐照组)。实验组使用217 HZ调制的1．8 GHz射频电磁场,SAR为2 W/kg,间断辐照24 h(5 min开/10 min关)；对照组置于同样的波导腔中,但不输入射频信号,进行假辐照。辐照后即刻抽提两组细胞的总RNA,然后用Rat Neurobiology U34 array基因芯片进行基因转录水平分析,找到可能的RF EMF反应候选基因。利用核糖核酸酶保护分析(RPA)法对功能相对明确、表达丰度和表达相对比值较高的变化基因进行验证。结果在Rat Neurobiology U34 array 1 200个候选基因中,筛选出34个差异表达基因,从中确定上调基因微管结合蛋白2(microtubule associated protein 2,Map2)为候选基因,经RPA方法验证,差异有统计学意义(P＜0．05)。结论Map2作为神经细胞特有的骨架蛋白,它的表达和功能的调控对于神经细胞维持正常细胞骨架和功能十分重要。1．8 GHz射频辐照可以引起大鼠神经细胞Map2基因表达上调。

Objective To investigate the changes of gene expression in rat neurons induced by 1.8 GHz radiofrequency electronmgnetic fields （RF EMF） and to screen for the RF EMF-responsive genes. Methods Newly-born SD rats in 24 hours were sacrificed to obtain cortex and hippocampus neurons. The cells were divided randomly into two groups： the experiment group（ the irradiation group） and the control group（ the false irradiation group）. In the irradiation group, after twelve days＇ culture, neurons were exposed to 1.8 GHz RF EMF modulated by 217 Hz at a specific absorption rate（SAR） of 2 W/kg for 24 hours（5 minutes on/10 minutes off） while in the false control group,the neurons were put in the same waveguide as in the irradiation group, but were not exposed to any irradiation. The total RNA was isolated and purified immediately after exposure. The affymetrix rat neurobiology U34 assay was used for detecting the changes in gene expression profile according to the manufac- turer＇ s instruction. RF EMF-respensive candidate gene was confirmed by using ribonuclease protection assay （RPA）. Results Among 1 200 candidate genes, the expression levels of 34 genes were up or down regulated. Microtubule associated protein 2（Map2） gene was selected as the candidate and subjected to further analysis. RPA data clearly revealed that Map2 was statistically significantly up-regulated after neurons were exposed to the RF EMF （ P 〈 0.05）. Conclusion The modulation of gene expression and function of Map2 as a neuron specific cytoskeleton protein is crucial to maintain the normal framework and function of neurons. The finding that 1.8 GHz RF EMF exposure increases the expression of Map2 might indicate some unknown effects of RF EMF on neurons.