Woodbine Lisa, Haines Jackie, Coster Margaret, Barazzuol Lara, Ainsbury Elizabeth, Sienkiewicz Zenon, Jeggo Penny
Genome Damage and Stability Centre, Life Sciences, University of Sussex , Brighton.
Int J Radiat Biol. 2015 Jun;91(6):495-9. doi: 10.3109/09553002.2015.1021963. Epub 2015 Mar 28.
Following in utero exposure to low dose radiation (10-200 mGy), we recently observed a linear induction of DNA double-strand breaks (DSB) and activation of apoptosis in the embryonic neuronal stem/progenitor cell compartment. No significant induction of DSB or apoptosis was observed following exposure to magnetic fields (MF). In the present study, we exploited this in vivo system to examine whether exposure to MF before and after exposure to 100 mGy X-rays impacts upon DSB repair rates.
53BP1 foci were quantified following combined exposure to radiation and MF in the embryonic neuronal stem/progenitor cell compartment. Embryos were exposed in utero to 50 Hz MF at 300 μT for 3 h before and up to 9 h after exposure to 100 mGy X-rays. Controls included embryos exposed to MF or X-rays alone plus sham exposures.
Exposure to MF before and after 100 mGy X-rays did not impact upon the rate of DSB repair in the embryonic neuronal stem cell compartment compared to repair rates following radiation exposure alone.
We conclude that in this sensitive system MF do not exert any significant level of DNA damage and do not impede the repair of X-ray induced damage.
在子宫内暴露于低剂量辐射(10 - 200毫戈瑞)后,我们最近观察到胚胎神经干细胞/祖细胞区室中DNA双链断裂(DSB)呈线性诱导以及细胞凋亡激活。暴露于磁场(MF)后未观察到DSB或细胞凋亡的显著诱导。在本研究中,我们利用这个体内系统来检查在暴露于100毫戈瑞X射线之前和之后暴露于MF是否会影响DSB修复率。
在胚胎神经干细胞/祖细胞区室联合暴露于辐射和MF后,对53BP1病灶进行定量分析。胚胎在子宫内于300微特斯拉的50赫兹MF下暴露3小时,在暴露于100毫戈瑞X射线之前以及之后长达9小时。对照组包括单独暴露于MF或X射线以及假暴露的胚胎。
与仅接受辐射暴露后的修复率相比,在100毫戈瑞X射线之前和之后暴露于MF对胚胎神经干细胞区室中的DSB修复率没有影响。
我们得出结论,在这个敏感系统中,MF不会造成任何显著程度的DNA损伤,也不会阻碍X射线诱导损伤的修复。