Current evidence for a role of epigenetic mechanisms in response to ionizing radiation in an ecotoxicological context

Abstract

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Towards solving a scientific controversy – The effects of ionising radiation on the environment

“…Hence, careful consideration of species specific and environmental information is needed for interpreting results on global DNA methylation. In some studies additional endpoints like levels of DNA damage or induction of DNA repair mechanisms or reactive oxygen species scavenging enzymes have been shown to concomitantly occur with changes in epigenetic marks, however, so far little evidence is available to mechanistically link these changes (Horemans et al, 2019).…”

“…A major conclusion of these studies was that global methylation alone may be too general a measure of epigenetic changes to see all biologically relevant differences induced by exposure to low dose rates and that more in depth (epi)genetic studies are needed (Horemans et al, 2019).…”

“…For example, ecological changes in community structure may result in communities entering different stable states from which return to the original condition is impaired. Further, when chemicals interact with the epigenome there is increasing evidence that this can lead to heritable changes in properties such as DNA methylation status, histones and even microRNA expression that can result in modified physiological states in direct progeny (and even later) generations (Horemans et al, 2019). For radiation, we can (probably uniquely for a pollutant) reconstruct past exposures with some confidence.…”

“…The mechanisms involved in organism responses to chronic radiation exposure, both within and between generations, are the subject of an active debate in the scientific literature (e.g. Boubriak et al, 2016;Carroll et al, 2007;Goodman et al, 2019;Horemans et al, 2019). Whilst adaptation of organisms to radiation within the CEZ has been suggested (Møller and Mousseau, 2016;Boubriak et al, 2008), it has not yet been the focus of any comprehensive research programme.…”

Long INterspersed element‐1 mobility as a sensor of environmental stresses

“…The molecular mechanisms underlying the biological effects of IR have long been studied and increasing evidence (Eden et al ., ; Huang et al ., ; Horemans et al ., ) suggests that the traditional paradigm (the breakage of one or both strands of the DNA double helix induced only by high dose exposures) should be changed toward an epigenetic model, which could also explain the risks linked to persistent exposures to small doses of ionizing radiations, as reported by Chernobyl studies (Burgio et al ., ). Following this stream of thought, it has been proposed that also the effect on L1‐RTP induced by IR could be mediated by epigenetic mechanisms.…”