scholarly journals Ionizing Radiation-Induced Epigenetic Modifications and Their Relevance to Radiation Protection

2020 ◽  
Vol 21 (17) ◽  
pp. 5993 ◽  
Author(s):  
Mauro Belli ◽  
Maria Antonella Tabocchini
Keyword(s):  
Gene Expression ◽  
Ionizing Radiation ◽  
Radiation Protection ◽  
Low Dose ◽  
Present System ◽  
Epigenetic Effects ◽  
Radiation Induced Cancer ◽  
Radiation Induced ◽  
Hereditary Effects ◽  
The Impact

The present system of radiation protection assumes that exposure at low doses and/or low dose-rates leads to health risks linearly related to the dose. They are evaluated by a combination of epidemiological data and radiobiological models. The latter imply that radiation induces deleterious effects via genetic mutation caused by DNA damage with a linear dose-dependence. This picture is challenged by the observation of radiation-induced epigenetic effects (changes in gene expression without altering the DNA sequence) and of non-linear responses, such as non-targeted and adaptive responses, that in turn can be controlled by gene expression networks. Here, we review important aspects of the biological response to ionizing radiation in which epigenetic mechanisms are, or could be, involved, focusing on the possible implications to the low dose issue in radiation protection. We examine in particular radiation-induced cancer, non-cancer diseases and transgenerational (hereditary) effects. We conclude that more realistic models of radiation-induced cancer should include epigenetic contribution, particularly in the initiation and progression phases, while the impact on hereditary risk evaluation is expected to be low. Epigenetic effects are also relevant in the dispute about possible “beneficial” effects at low dose and/or low dose-rate exposures, including those given by the natural background radiation.

Low-Dose Ionizing Radiation from Medical Imaging

2016 ◽  
Author(s):  
Christoph I. Lee
Keyword(s):  
Medical Imaging ◽  
Ionizing Radiation ◽  
Radiation Exposure ◽  
Low Dose ◽  
Additional Information ◽  
Radiation Induced Cancer ◽  
Radiation Induced ◽  
Effective Doses ◽  
Study Methodology ◽  
Ionizing Radiation Exposure

This chapter, found in the radiation exposure from medical imaging section of the book, provides a succinct synopsis of a key study examining low-dose ionizing radiation exposure and radiation-induced cancer risks. This summary outlines the study methodology and design, major results, limitations and criticisms, related studies and additional information, and clinical implications. The study reported that a substantial proportion of the nonelderly US population is exposed to medium to very high annual effective doses from medical imaging procedures. Strategies ensuring the appropriate use of medical imaging associated with ionizing radiation should be developed and adopted widely. In addition to outlining the most salient features of the study, a clinical vignette is included in order to provide relevant clinical context.

scholarly journals Exposure to Low to Moderate Doses of Ionizing Radiation Induces A Reduction of Pro-Inflammatory Ly6chigh Monocytes and a U-Curved Response of T Cells in APOE -/- Mice

Dose-Response ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 155932582110162
Author(s):  
N. Rey ◽  
T. Ebrahimian ◽  
C. Gloaguen ◽  
D. Kereselidze ◽  
V. Magneron ◽  
...  
Keyword(s):  
Gene Expression ◽  
Ionizing Radiation ◽  
Dose Rate ◽  
Low Dose ◽  
T Cell Subsets ◽  
System Response ◽  
Dose Rates ◽  
Low Dose Rate ◽  
Inflammatory Monocytes ◽  
The Impact

Low dose ionizing radiation (LDIR) is known to have a protective effect on atherosclerosis in rodent studies, but how it impacts different cells types involved in lesion formation remains incompletely understood. We investigated the immunomodulatory response of different doses and dose-rates of irradiation in ApoE-/- mice. Mice were exposed to external γ rays at very low (1.4 mGy.h-1) or low (50 mGy.h-1) dose-rates, with cumulative doses spanning 50 to 1000 mGy. Flow cytometry of circulating cells revealed a significant decrease in pro-inflammatory Ly6CHi monocytes at all cumulative doses at low dose-rate, but more disparate effects at very low dose-rate with reductions in Ly6CHi cells at doses of 50, 100 and 750 mGy only. In contrast, Ly6CLo monocytes were not affected by LDIR. Similarly, proportions of CD4+ T cell subsets in the spleen did not differ between irradiated mice and non-irradiated controls, whether assessing CD25+FoxP3+ regulatory or CD69+ activated lymphocytes. In the aorta, gene expression of cytokines such as IL-1 and TGF-ß and adhesion molecules such as E-Selectin, ICAM-1, and VCAM-1 were reduced at the intermediate dose of 200 mGy. These results suggest that LDIR may reduce atherosclerotic plaque formation by selectively reducing blood pro-inflammatory monocytes and by impairing adhesion molecule expression and inflammatory processes in the vessel wall. In contrast, splenic T lymphocytes were not affected by LDIR. Furthermore, some responses to irradiation were nonlinear; reductions in aortic gene expression were significant at intermediate doses, but not at either highest or lowest doses. This work furthers our understanding of the impact of LDIR with different dose-rates on immune system response in the context of atherosclerosis.

scholarly journals Extracellular vesicles mediate low dose ionizing radiation-induced immune and inflammatory responses in the blood

2018 ◽  
Vol 95 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Tünde Szatmári ◽  
Eszter Persa ◽  
Enikő Kis ◽  
Anett Benedek ◽  
Rita Hargitai ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Extracellular Vesicles ◽  
Low Dose ◽  
Inflammatory Responses ◽  
Radiation Induced

Gene expression changes in mouse brain after exposure to low‐dose ionizing radiation

2003 ◽  
Vol 79 (10) ◽  
pp. 759-775 ◽  
Author(s):  
E. Yin ◽  
D. O. Nelson ◽  
M. A. Coleman ◽  
L. E. Peterson ◽  
A. J. Wyrobek
Keyword(s):  
Gene Expression ◽  
Ionizing Radiation ◽  
Mouse Brain ◽  
Low Dose

scholarly journals Low dose ionizing radiation induced acoustic neuroma: A putative link?

2012 ◽  
Vol 01 (01) ◽  
pp. 078-079
Author(s):  
Sachin Borkar ◽  
Deepak Agrawal
Keyword(s):  
Ionizing Radiation ◽  
Brain Tumors ◽  
Acoustic Neuroma ◽  
Cumulative Dose ◽  
Low Dose ◽  
High Dose ◽  
Atomic Reactor ◽  
Radiation Induced

Abstract Although exposure to high dose ionizing radiation (following therapeutic radiotherapy) has been incriminated in the pathogenesis of many brain tumors, exposure to chronic low dose ionizing radiation has not yet been shown to be associated with tumorigenesis. The authors report a case of a 50-year-old atomic reactor scientist who received a cumulative dose of 78.9 mSv over a 10-year period and was detected to have an acoustic neuroma another 15 years later. Although there is no proof that exposure to ionizing radiation was the cause for the development of the acoustic neuroma, this case highlights the need for extended follow-up periods following exposure to low dose ionizing radiation.

scholarly journals Radiation-Induced Cerebro-Ophthalmic Effects in Humans

Life ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 41 ◽  
Author(s):  
Konstantin N. Loganovsky ◽  
Donatella Marazziti ◽  
Pavlo A. Fedirko ◽  
Kostiantyn V. Kuts ◽  
Katerina Y. Antypchuk ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Human Brain ◽  
Neurodegenerative Diseases ◽  
Brain Damage ◽  
Optic Neuropathy ◽  
Radiation Effects ◽  
Low Dose ◽  
Neurocognitive Deficits ◽  
Radiation Induced ◽  
Available Information

Exposure to ionizing radiation (IR) could affect the human brain and eyes leading to both cognitive and visual impairments. The aim of this paper was to review and analyze the current literature, and to comment on the ensuing findings in the light of our personal contributions in this field. The review was carried out according to the PRISMA guidelines by searching PubMed, Scopus, Embase, PsycINFO and Google Scholar English papers published from January 2000 to January 2020. The results showed that prenatally or childhood-exposed individuals are a particular target group with a higher risk for possible radiation effects and neurodegenerative diseases. In adulthood and medical/interventional radiologists, the most frequent IR-induced ophthalmic effects include cataracts, glaucoma, optic neuropathy, retinopathy and angiopathy, sometimes associated with specific neurocognitive deficits. According to available information that eye alterations may induce or may be associated with brain dysfunctions and vice versa, we propose to label this relationship “eye-brain axis”, as well as to deepen the diagnosis of eye pathologies as early and easily obtainable markers of possible low dose IR-induced brain damage.

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