Masuda Shinya, Hisamatsu Tsubasa, Seko Daiki, Urata Yoshishige, Goto Shinji, Li Tao-Sheng, Ono Yusuke
Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
Physiol Rep. 2015 Apr;3(4). doi: 10.14814/phy2.12377.
Exposure to high levels of genotoxic stress, such as high-dose ionizing radiation, increases both cancer and noncancer risks. However, it remains debatable whether low-dose ionizing radiation reduces cellular function, or rather induces hormetic health benefits. Here, we investigated the effects of total-body γ-ray radiation on muscle stem cells, called satellite cells. Adult C57BL/6 mice were exposed to γ-radiation at low- to high-dose rates (low, 2 or 10 mGy/day; moderate, 50 mGy/day; high, 250 mGy/day) for 30 days. No hormetic responses in proliferation, differentiation, or self-renewal of satellite cells were observed in low-dose radiation-exposed mice at the acute phase. However, at the chronic phase, population expansion of satellite cell-derived progeny was slightly decreased in mice exposed to low-dose radiation. Taken together, low-dose ionizing irradiation may suppress satellite cell function, rather than induce hormetic health benefits, in skeletal muscle in adult mice.
暴露于高水平的遗传毒性应激，如高剂量电离辐射，会增加患癌风险和非癌风险。然而，低剂量电离辐射是会降低细胞功能，还是会带来有益健康的兴奋效应，这一点仍存在争议。在此，我们研究了全身γ射线辐射对肌肉干细胞（即卫星细胞）的影响。将成年C57BL/6小鼠暴露于低至高剂量率的γ辐射下（低剂量，2或10毫戈瑞/天；中等剂量，50毫戈瑞/天；高剂量，250毫戈瑞/天），持续30天。在急性期，低剂量辐射暴露小鼠的卫星细胞增殖、分化或自我更新未观察到兴奋效应。然而，在慢性期，低剂量辐射暴露小鼠的卫星细胞衍生后代的群体扩增略有减少。综上所述，低剂量电离辐射可能会抑制成年小鼠骨骼肌中卫星细胞的功能，而不是带来有益健康的兴奋效应。
