Hurem Selma, Gomes Tânia, Brede Dag A, Lindbo Hansen Elisabeth, Mutoloki Stephen, Fernandez Cristian, Mothersill Carmel, Salbu Brit, Kassaye Yetneberk A, Olsen Ann-Karin, Oughton Deborah, Aleström Peter, Lyche Jan L
Centre for Environmental Radioactivity (CERAD CoE), NMBU, 1433 Ås, Norway; Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine and Biosciences, P.O. Box 8146 Dep., 0033 Oslo, Norway.
Centre for Environmental Radioactivity (CERAD CoE), NMBU, 1433 Ås, Norway; Norwegian Institute for Water research (NIVA), Gaustadalléen 21, NO-0349 Oslo, Norway.
Environ Res. 2017 Nov;159:564-578. doi: 10.1016/j.envres.2017.07.053. Epub 2017 Sep 9.
Gamma radiation represents a potential health risk to aquatic and terrestrial biota, due to its ability to ionize atoms and molecules in living tissues. The effects of exposure to Co gamma radiation in zebrafish (Danio rerio) were studied during two sensitive life stages: gametogenesis (F0: 53 and 8.7mGy/h for 27 days, total doses 31 and 5.2Gy) and embryogenesis (9.6mGy/h for 65h; total dose 0.62Gy). Progeny of F0 exposed to 53mGy/h showed 100% mortality occurring at the gastrulation stage corresponding to 8h post fertilization (hpf). Control and F0 fish exposed to 8.7mGy/h were used to create four lines in the first filial generation (F1): control, G line (irradiated during parental gametogenesis), E line (irradiated during embryogenesis) and GE line (irradiated during parental gametogenesis and embryogenesis). A statistically significant cumulative mortality of GE larva (9.3%) compared to controls was found at 96 hpf. E line embryos hatched significantly earlier compared to controls, G and GE (48-72 hpf). The deformity frequency was higher in G and GE, but not E line compared to controls at 72 hpf. One month after parental irradiation, the formation of reactive oxygen species (ROS) was increased in the G line, but did not significantly differ from controls one year after parental irradiation, while at the same time point it was significantly increased in the directly exposed E and GE lines from 60 to 120 hpf. Lipid peroxidation (LPO) was significantly increased in the G line one year after parental irradiation, while significant increase in DNA damage was detected in both the G and GE compared to controls and E line at 72 hpf. Radiation-induced bystander effects, triggered by culture media from tissue explants and observed as influx of Ca ions through the cellular membrane of the reporter cells, were significantly increased in 72 hpf G line progeny one month after irradiation of the parents. One year after parental irradiation, the bystander effects were increased in the E line compared to controls, but not in progeny of irradiated parents (G and GE lines). Overall, this study showed that irradiation of parents can result in multigenerational oxidative stress and genomic instability in irradiated (GE) and non-irradiated (G) progeny of irradiated parents, including increases in ROS formation, LPO, DNA damage and bystander effects. The results therefore highlight the necessity for multi- and transgenerational studies to assess the environmental impact of gamma radiation.
伽马辐射对水生和陆生生物群构成潜在的健康风险，因为它能够使活组织中的原子和分子发生电离。本研究在斑马鱼（Danio rerio）两个敏感的生命阶段，即配子发生期（F0：53和8.7mGy/h，持续27天，总剂量分别为31和5.2Gy）和胚胎发生期（9.6mGy/h，持续65小时；总剂量0.62Gy），研究了钴伽马辐射的暴露影响。暴露于53mGy/h的F0代子代在受精后8小时（hpf）的原肠胚形成阶段出现100%的死亡率。将暴露于8.7mGy/h的对照鱼和F0代鱼用于创建第一代（F1）的四个品系：对照品系、G品系（亲代配子发生期受辐照）、E品系（胚胎发生期受辐照）和GE品系（亲代配子发生期和胚胎发生期均受辐照）。在96 hpf时，发现GE幼虫的累积死亡率（9.3%）与对照相比有统计学显著差异。E品系胚胎比对照、G品系和GE品系孵化得明显更早（48 - 72 hpf）。在72 hpf时，G品系和GE品系的畸形频率高于对照，但E品系与对照相比无差异。亲代辐照后一个月，G品系中活性氧（ROS）的形成增加，但亲代辐照一年后与对照无显著差异，而在同一时间点，直接暴露的E品系和GE品系在60至120 hpf时ROS显著增加。亲代辐照一年后，G品系中的脂质过氧化（LPO）显著增加，而在72 hpf时，与对照品系和E品系相比，G品系和GE品系的DNA损伤均显著增加。由组织外植体的培养基引发并表现为钙离子通过报告细胞的细胞膜内流的辐射诱导旁观者效应，在亲代辐照一个月后的72 hpf G品系子代中显著增加。亲代辐照一年后，E品系中的旁观者效应与对照相比增加，但在受辐照亲代的子代（G品系和GE品系）中未增加。总体而言，本研究表明亲代辐照可导致受辐照亲代的受辐照（GE）和未受辐照（G）子代出现多代氧化应激和基因组不稳定，包括ROS形成、LPO、DNA损伤和旁观者效应增加。因此，研究结果突出了进行多代和跨代研究以评估伽马辐射对环境影响的必要性。
