Tokalov Sergey V, Gutzeit Herwig O
Institut für Zoologie, Technische Universität Dresden, Mommsenstr. 13, D-01062 Dresden, Germany.
Environ Res. 2004 Feb;94(2):145-51. doi: 10.1016/s0013-9351(03)00088-4.
The aim of this study was to demonstrate the expression of heat shock (HS) genes in human cells in response to extremely low-frequency electromagnetic fields (ELF-EMF) alone and in combination with thermal stress. After exposing human myeloid leukemia (HL-60) cells to the stressor(s) for 30 min we quantified the expression of the HS genes HSP27, HSP60, HSP70 (A, B, and C), HSC70, HSP75, HSP78, and HSP90 (alpha and beta) by RT-PCR. The results clearly show that HS genes, in particular the three HSP70 genes (A, B, and C), are induced by ELF-EMF, a reaction that is enhanced by simultaneous HS (43 degrees C for 30 min). The results show similarities and some significant differences to previous experiments in which transgenic nematodes were used to monitor the induction of the HSP70 gene under similar stress conditions. We also studied the effect of different flux densities on gene expression in the range of 10-140 microT. Even the lowest dose tested (10 microT) resulted in a significant induction of the genes HSP70A, HSP70B, and HSP70C. The reaction to ELF-EMF shows a maximum at a flux density of 60-80 microT. The unusual dose-response relation reveals an interesting difference to other stressors that elicit the HS response.
本研究的目的是证明热休克（HS）基因在人类细胞中对极低频电磁场（ELF-EMF）单独作用以及与热应激联合作用时的表达情况。将人类髓系白血病（HL-60）细胞暴露于应激源30分钟后，我们通过逆转录聚合酶链反应（RT-PCR）对HS基因HSP27、HSP60、HSP70（A、B和C）、HSC70、HSP75、HSP78和HSP90（α和β）的表达进行定量分析。结果清楚地表明，HS基因，特别是三个HSP70基因（A、B和C），可被ELF-EMF诱导，同时热休克（43℃，30分钟）可增强这一反应。这些结果与之前使用转基因线虫在类似应激条件下监测HSP70基因诱导情况的实验有相似之处，也存在一些显著差异。我们还研究了10 - 140微特斯拉范围内不同通量密度对基因表达的影响。即使是测试的最低剂量（10微特斯拉）也导致HSP70A、HSP70B和HSP70C基因的显著诱导。对ELF-EMF的反应在通量密度为60 - 80微特斯拉时达到最大值。这种不寻常的剂量反应关系揭示了与引发HS反应的其他应激源的有趣差异。
