論文

査読有り
2020年12月10日

Repair Kinetics of DNA Double Strand Breaks Induced by Simulated Space Radiation

Life
  • Takashi Oizumi
  • ,
  • Rieko Ohno
  • ,
  • Souichiro Yamabe
  • ,
  • Tomoo Funayama
  • ,
  • Asako J. Nakamura

10
12
開始ページ
341
終了ページ
341
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.3390/life10120341
出版者・発行元
MDPI AG

Radiation is unavoidable in space. Energetic particles in space radiation are reported to induce cluster DNA damage that is difficult to repair. In this study, normal human fibroblasts were irradiated with components of space radiation such as proton, helium, or carbon ion beams. Immunostaining for γ-H2AX and 53BP1 was performed over time to evaluate the kinetics of DNA damage repair. Our data clearly show that the repair kinetics of DNA double strand breaks (DSBs) induced by carbon ion irradiation, which has a high linear energy transfer (LET), are significantly slower than those of proton and helium ion irradiation. Mixed irradiation with carbon ions, followed by helium ions, did not have an additive effect on the DSB repair kinetics. Interestingly, the mean γ-H2AX focus size was shown to increase with LET, suggesting that the delay in repair kinetics was due to damage that is more complex. Further, the 53BP1 focus size also increased in an LET-dependent manner. Repair of DSBs, characterized by large 53BP1 foci, was a slow process within the biphasic kinetics of DSB repair, suggesting non-homologous end joining with error-prone end resection. Our data suggest that the biological effects of space radiation may be significantly influenced by the dose as well as the type of radiation exposure.

リンク情報
DOI
https://doi.org/10.3390/life10120341
URL
https://www.mdpi.com/2075-1729/10/12/341/pdf
ID情報
  • DOI : 10.3390/life10120341
  • eISSN : 2075-1729

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