极低频磁场对细胞色素氧化酶亚基1基因转录水平的影响

The effect of extremely low frequency magnetic fields on cytochrome oxidase subunit 1 mRNA transcription

目的 克隆和鉴定本研究室经DD法在Daudi细胞中筛选到的一个极低频磁场的特异反应基因 (MF 1) ,并在多种磁场敏感细胞中证实该基因反应的普遍性 ,为揭示磁场所致生物学效应的作用机制提供实验依据。方法 克隆、序列分析MF 1片段 ;选择HL 6 0、L12 10和中国仓鼠肺成纤维细胞 (CHL)等细胞 ,用Northern技术观察该基因在不同条件的磁场辐照 (5 0Hz磁场 ,磁通密度分别是 0 .1mT和 0 .8mT ,辐照时间分别是 2 0min和 2 4h)后该基因转录水平的变化。结果 克隆测序及与GeneBank同源性比较表明 ,MF 1序列与细胞色素氧化酶亚基 1基因 (CO1)有 10 0 %同源性。HL 6 0、L12 10和CHL等细胞在 0 .1mT、0 .8mT磁场辐照 2 0min后 ,CO1转录水平 (分别为 0 .38± 0 .12、0 .37± 0 .0 4 )均比对照组 (0 .5 8± 0 .12 )下降 ,差异有显著性 (P <0 .0 5 ) ;辐照 2 4h后 ,3种细胞该基因转录水平 (分别为 0 .4 6± 0 .0 9、0 .4 5± 0 .0 9)亦比对照组 (0 .6 5± 0 .0 6 )下降 ,差异有显著性 (P <0 .0 5 )。结论 CO1是磁场辐照密切相关的反应基因之一。磁场可能通过影响CO1的转录水平来影响细胞色素氧化酶的活力 。

Objective To clone and identify MF 1 gene which responded to extremely low frequency magnetic fields(ELF MF) in Daudi cells,and explore the response universality of MF 1 gene in several MF sensitive cell lines,so as to provide experimental basis for revealing the mechanism of biological effects induced by magnetic field. Methods The DNA fragment of MF 1 was cloned and sequenced;the mRNA level of MF 1 gene were analysed in MF sensitive cell lines(HL 60,L1210 and CHL) by Northern blot after these cells being treated with 0.1 mT and 0.8 mT MF for 20 minutes and 24 hours,respectively. Results The MF 1 cDNA sequence had 100% homology with cytochrome oxidase subunit 1 gene(CO1) by searching Gene Bank database;the transcription of CO1 in HL 60,L1210 and CHL cell lines which exposed to 0.1 mT and 0.8 mT MF for 20 minutes were significantly lower(0.38±0.12 and 0.37±0.04) than that of control(0.58±0.12) and so did for 24 hours exposure(0.46±0.09 and 0.45±0.09 vs 0.65±0.06)(P<0.05). Conclusion CO1 is a MF responsive gene.Cytochrome oxidase activity may be affected through low level of CO1 transcription by magnetic fields,thus induce bioeffects in organisms.