Inverse dose-rate effect of ionising radiation on residual 53BP1 foci in the eye lens

Barnard, SGR; McCarron, R; Moquet, J; Quinlan, RA; Ainsbury, E

Abstract

The influence of dose rate on radiation cataractogenesis has yet to be extensively studied. One recent epidemiological investigation suggested that protracted radiation exposure increases radiation-induced cataract risk: cumulative doses of radiation mostly <100 mGy received by US radiologic technologists over 5 years were associated with an increased excess hazard ratio for cataract development. However, there are few mechanistic studies to support and explain such observations. Low-dose radiation-induced DNA damage in the epithelial cells of the eye lens (LECs) has been proposed as a possible contributor to cataract formation and thus visual impairment. Here, 53BP1 foci was used as a marker of DNA damage. Unexpectedly, the number of 53BP1 foci that persisted in the mouse lens samples after γ-radiation exposure increased with decreasing dose-rate at 4 and 24 h. The C57BL/6 mice were exposed to 0.5, 1 and 2 Gy ƴ-radiation at 0.063 and 0.3 Gy/min and also 0.5 Gy at 0.014 Gy/min. This contrasts the data we obtained for peripheral blood lymphocytes collected from the same animal groups, which showed the expected reduction of residual 53BP1 foci with reducing dose-rate. These findings highlight the likely importance of dose-rate in low-dose cataract formation and, furthermore, represent the first evidence that LECs process radiation damage differently to blood lymphocytes.

Citation

Barnard, S., McCarron, R., Moquet, J., Quinlan, R., & Ainsbury, E. (2019). Inverse dose-rate effect of ionising radiation on residual 53BP1 foci in the eye lens. Scientific Reports, 9, Article 10418. https://doi.org/10.1038/s41598-019-46893-3

• Journal Article Type: Article
• Acceptance Date: Jul 2, 2019
• Online Publication Date: Jul 18, 2019
• Publication Date: 2019
• Deposit Date: Jul 10, 2019
• Publicly Available Date: Jul 19, 2019
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Article Number: 10418
• DOI: https://doi.org/10.1038/s41598-019-46893-3
• Public URL: https://durham-repository.worktribe.com/output/1327273