Simulated microgravity potentiates generation of reactive oxygen species in cells.
Simulated microgravity potentiates generation of reactive oxygen species in cells.
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模拟微重力增强细胞中活性氧的产生
DOI：
10.1007/s41048-016-0029-0
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发表时间：
2016
影响因子：
--
通讯作者：
Wang S
中科院分区：
文献类型：
--
作者：
Ran F;An L;Fan Y;Hang H;Wang S
微重力(MG)和空间辐射是空间环境的两个主要环境因素。电离辐射产生的活性氧(ROS)在辐射诱导的DNA损伤中起着关键作用。有趣的是，模拟微重力(SMG)也增加了不同类型细胞中ROS的产生。因此，检测SMG是否能增强包括辐射在内的基因毒素诱导的ROS产生，特别是在不足以诱导可检测到的ROS的最低水平上，是很重要的。在本研究中，我们用H_2O_2和SMG处理小鼠胚胎干细胞(MES)24小时，所用H_2O_2浓度在30μ/L范围内，细胞内ROS与未处理细胞相同。SMG作用于细胞24小时后，细胞内ROS水平也未明显高于对照组。同时暴露于SMG和H_2O_2可诱导MES细胞的ROS和细胞凋亡。在含5或30μ摩尔/L H_2O_2的培养液中孵育后，DNA双链断裂(DSB)略有增加，但SMG处理显著增加了DSB的水平。综上所述，SMG可以显著增强低浓度的H_2O_2对ROS、细胞凋亡和DNA损伤的影响。本研究还讨论了空间辐射和MG对人体的联合作用。
Microgravity (MG) and space radiation are two major environmental factors of space environment. Ionizing radiation generates reactive oxygen species (ROS) which plays a key role in radiation-induced DNA damage. Interestingly, simulated microgravity (SMG) also increases ROS production in various cell types. Thus, it is important to detect whether SMG could potentiate ROS production induced by genotoxins including radiation, especially at a minimal level not sufficient to induce detectable ROS. In this study, we treated mouse embryonic stem (MES) cells with H2O2 and SMG for 24 h. The concentration of H2O2 used was within 30 μmol/L at which intracellular ROS was the same as that in untreated cells. Exposure of cells to SMG for 24 h did not induce significantly higher levels of intracellular ROS than that of control cells either. Simultaneous exposure of cells to both SMG- and H2O2-induced ROS and apoptosis in MES cells. Although incubation in medium containing 5 or 30 μmol/L H2O2 induced a small enhancement of DNA double-strand breaks (DSBs), the addition of SMG treatment dramatically increased DSB levels. Taken together, SMG can significantly potentiate the effects of H2O2 at a low concentration that induce a small or negligible change in cells on ROS, apoptosis, and DNA damage. The results were discussed in relation to the combined effects of space radiation and MG on human body in this study.