Biological Effects of Low Dose and Low Dose Rate Irradiation
Biological Effects of Low Dose and Low Dose Rate Irradiation
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低剂量和低剂量率辐照的生物学效应
DOI：
10.11242/dentalradiology.61.1
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
小林純也
中科院分区：
文献类型：
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作者：
勝木陽子;安倍昌子;Haico van Attikum;中田慎一郎;鐘巻将人;Yonghwan Kim;矢部みはる;矢部普正;高田 穣.;小林純也
福岛第一核电站事故发生后，日本很多人对低剂量、低剂量率辐射的生物效应感到担忧。在这种情况下，一些人也对辐射用于诊断和治疗产生了担忧。由于现行的《医疗法修正案》严格规定了辐射诊断规则，为医疗治疗辐射的医务工作者必须了解电离辐射照射的生物效应，以解释医疗辐射对患者的影响。急性高剂量辐射可引起多种类型的DNA损伤。其中，DNA双链断裂（DNA double -strand breaks， DSB）是对细胞和构造器官最严重的损伤，因为DSB损伤的残留会导致细胞死亡，进而导致器官功能障碍（deterministic effects）。因此，生物正在发展非同源末端连接和同源重组等DNA修复系统。缺失修复和不修复可产生基因突变，进而导致肿瘤发生（随机效应）。辐射暴露还会引起活性氧（ROS）的过量积累/氧化应激，这可能导致低剂量率辐射的生物效应。我们发现，在低剂量率照射下，线粒体损伤有助于人体正常成纤维细胞ROS的积累和氧化应激的激活。我们还观察到，在ATM抑制剂存在的情况下，低剂量率照射也引起γ - h2ax阳性微核。由于ATM是氧化应激反应和DNA损伤反应的重要蛋白激酶，抗氧化应激功能可能对抑制微核形成很重要。为了减轻人们的忧虑，我们有必要进一步阐明低剂量和低剂量率辐射的生物学效应。(作者)
[en] After the accident of Fukushima Daiichi nuclear power plant, many people in Japan have a concern about biological effect with low dose and low dose rate radiation. In such situation, some people also have concerns to radiation usage for diagnostics and therapies. As the current amendment of medical law provides the rules of radiation diagnostics strictly, medical workers, treating radiation for medical, have to understand the biological effects with exposure to ionizing radiation to explain the effects of medical radiation to patients. Acute irradiation of high dose radiation induces several types of DNA damages. Among of them, DNA doble-strand breaks (DSBs) are most serious damages to cells and constructing organs, because remaining of DSB damages could lead to cell death, subsequently dysfunction of organs (deterministic effects). Therefore, living beings are developing DNA repair systems such as non-homologous end-joining and homologous recombination. Miss-repair and non-repair could generate gene mutation, and subsequently lead to tumorigenesis (stochastic effects). Exposure of radiation also causes excess accumulation of ROS (reactive oxygen species)/oxidative stress, which may lead to biological effects of low dose rate radiation. We found that mitochondria damage contributed to accumulation of ROS and activation of oxidative stress in human normal fibroblasts under low dose rate irradiation. We also observed that low dose rate irradiation also caused gamma-H2AX positive micronuclei in the presence of ATM inhibitor. As ATM is an important protein kinase of oxidative stress responses as well as DNA damage responses, anti-oxidative stress function may be important to repress micronuclei formation. In order to provide relief to concerning people, we have to clarify the biological effects of low dose and low dose rate radiation more.(author)