Fibroblasts from bank voles inhabiting Chernobyl have increased resistance against oxidative and DNA stresses

Abstract

BackgroundElevated levels of environmental ionizing radiation can be a selective pressure for wildlife by producing reactive oxygen species and DNA damage. However, the underlying molecular mechanisms that are affected are not known.ResultsWe isolated skin fibroblasts from bank voles (Myodes glareolus) inhabiting the Chernobyl nuclear power plant accident site where background radiation levels are about 100 times greater than in uncontaminated areas. After a 10 Gy dose of gamma radiation fibroblasts from Chernobyl animals recovered faster than fibroblasts isolated from bank voles living in uncontaminated control area. The Chernobyl fibroblasts were able to sustain significantly higher doses of an oxidant and they had, on average, a higher total antioxidant capacity than the control fibroblasts. Furthermore, the Chernobyl fibroblasts were also significantly more resistant than the control fibroblasts to continuous exposure to three DNA damaging drugs. After drug treatment transcription of p53-target gene pro-apoptotic Bax was higher in the control than in the Chernobyl fibroblasts.ConclusionFibroblasts isolated from bank voles inhabiting Chernobyl nuclear power plant accident site show elevated antioxidant levels, lower sensitivity to apoptosis, and increased resistance against oxidative and DNA stresses. These cellular qualities may help bank voles inhabiting Chernobyl to cope with environmental radioactivity.Electronic supplementary materialThe online version of this article (10.1186/s12860-018-0169-9) contains supplementary material, which is available to authorized users.

Exposure to environmental radionuclides is associated with altered metabolic and immunity pathways in a wild rodent

“…Elevated expression of cell cycle regulators can also increase resistance to oxidative and genotoxic stress as well as to starvation in Drosophila (Moskalev et al, ). Indeed, fibroblast cells isolated from bank voles from the CEZ show increased resistance to cell death against DNA damaging agents, and can more efficiently recover after irradiation (acute high dose of 10 Gy) (Mustonen et al, ), contrary to a pattern of premature senescence and loss of proliferation ability commonly seen in cells sensitive to radiation (Loseva et al, ). Within the approximately 50 generations of inhabiting the CEZ (Baker et al, ), bank voles may have evolved some resistance to radiation induced DNA damage and oxidative stress (see also Galvan et al, ), or are not receiving a sufficiently high dose of radiation to inflict a DNA repair response.…”

Infection Load and Prevalence of Novel Viruses Identified from the Bank Vole Do Not Associate with Exposure to Environmental Radioactivity

“…Parvoviridae are linear, single-stranded DNA viruses with a genome of 4-6 kb that codes for structural proteins (capsid) and replication protein (REP). Parvoviruses are non-enveloped viruses with two terminal hairpin structures, which prime replication [39]. Parvoviruses infect vertebrate (Parvovirinae) and invertebrate (Densovirinae) hosts [40].…”

“…Virus activation by irradiation may be facilitated by radiation-mediated immunosuppression that makes the host more susceptible to virus infection and replication [33][34][35], or by radiation-induced activation of the DNA repair proteins that some viruses utilize in their replication [36,37]. Wild bank voles exposed to chronic low-dose (up to 20 µGy/h) environmental radiation show activated transcription of DNA repair proteins [38] and inhibited apoptosis [39], and show signs of immunosuppression [40]. As these processes may support virus replication, we predicted an elevated viral load in bank voles inhabiting areas contaminated by radionuclides compared with uncontaminated areas.…”

Exposure to environmental radionuclides alters mitochondrial DNA maintenance in a wild rodent

“…Current patterns of mitochondrial dynamics may also have been shaped by selection or epigenetic effects in the vole population recolonizing the contaminated CEZ area after the accident (Omar-Nazir et al 2018). Interestingly, skin fibroblasts isolated from bank voles inhabiting the contaminated area of the CEZ have greater resistance against oxidative and DNA damaging stressors and elevated basal antioxidant levels compared to cells from control voles collected from outside the CEZ (Mustonen et al 2018). While inhabiting an environment contaminated with radionuclides can induce elevated levels of oxidative stress, DNA damage and mutation rate (Møller and Mousseau 2015;Einor et al 2016;Lourenço et al 2016), there is no evidence for an increased rate of accumulation of mutations in the mitochondrial genome, i.e.…”