Adaptive response to ionising radiation induced by cadmium in zebrafish embryos

Abstract

An adaptive response is a biological response where the exposure of cells or animals to a low priming exposure induces mechanisms that protect the cells or animals against the detrimental effects of a subsequent larger challenging exposure. In realistic environmental situations, living organisms can be exposed to a mixture of stressors, and the resultant effects due to such exposures are referred to as multiple stressor effects. In the present work we demonstrated, via quantification of apoptosis in the embryos, that embryos of the zebrafish (Danio rerio) subjected to a priming exposure provided by one environmental stressor (cadmium in micromolar concentrations) could undergo an adaptive response against a subsequent challenging exposure provided by another environmental stressor (alpha particles). We concluded that zebrafish embryos treated with 1 to 10 μM Cd at 5 h postfertilisation (hpf) for both 1 and 5 h could undergo an adaptive response against subsequent ~4.4 mGy alpha-particle irradiation at 10 hpf, which could be interpreted as an antagonistic multiple stressor effect between Cd and ionising radiation. The zebrafish has become a popular vertebrate model for studying the in vivo response to ionising radiation. As such, our results suggested that multiple stressor effects should be carefully considered for human radiation risk assessment since the risk may be perturbed by another environmental stressor such as a heavy metal.

Embryonic ionizing radiation exposure results in expression alterations of genes associated with cardiovascular and neurological development, function, and disease and modified cardiovascular function in zebrafish

“…Previous studies using the zebrafish model system to evaluate ionizing radiation exposure have been used to assess general toxicity (e.g., mortality, hatching rates, gross morphological alterations, DNA damage, and apoptosis) (e.g., Bladen et al, 2007; Choi et al, 2010a,b, 2012a, 2013; Pereira et al, 2011; Sorrells et al, 2012; Yu et al, 2012; Toruno et al, 2014), to screen radiation protectors (McAleer et al, 2005; Geiger et al, 2006), and to assess the long-term effects on liver gene expression (Jaafar et al, 2013). To the best of our knowledge, no work is published on the effect of IR to heart rate using the zebrafish model.…”

Low-dose neutron dose response of zebrafish embryos obtained from the Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) facility

“…The zebrafish and the embryos have been widely used in studies on the biological effects of ionizing radiation (e.g., refs. Bladen et al, 2005;Geiger et al, 2006;Daroczi et al, 2006;Mothersill et al, 2007;Yum et al, 2007;Choi and Yu, 2015;Choi et al, 2010aChoi et al, , 2010bChoi et al, , 2012aChoi et al, , , 2013aChoi et al, , , 2013bKong et al, 2014) due to its rapid development, fecundity and the fact that zebrafish and human genomes share considerable homology, including conservation of most DNA repair-related genes (Barbazuk et al, 2000).…”

Embryos of the zebrafish Danio rerio in studies of non-targeted effects of ionizing radiation

“…In fact, humans and other living organisms are inevitably exposed to naturally occurring alpha particles. For example, alpha particles, which have high LET values, are continuously emitted by members of the natural 238 U decay series, e.g., 238 U and 226 Ra, which are present in geological materials, including rocks and soils. Within this 238 U decay series, there is a member, 222 Rn, which is a natural radioactive gas called radon, which poses health hazard to living organisms.…”

“…In reality, living organisms are exposed to a mixture of environmental stressors, e.g., ionizing radiations, heavy metals, etc., and the resultant effects due to such exposures are called multiple stressor effects. The evidence showed that toxicity could be modified by simultaneous or sequential exposures to multiple environmental agents [225][226][227].…”