X射线致人外周血线粒体DNA 4977bp缺失的时效关系研究

Time-effect Relationship of Mitochondrial DNA 4977bp Deletion in Human Peripheral Blood Cell after X Ray Irradiation

采集2名25岁健康男性外周血进行不同剂量(0～10 Gy)单次X射线照射,于照后取不同时间点(2、12、24、48和72 h)培养的细胞提取基因组DNA,利用实时定量PCR检测不同时间点线粒体DNA(mtDNA)4977bp缺失情况,探讨X射线致人外周血mtDNA 4977bp缺失的时间效应关系。结果表明,受照剂量为5 Gy时,随着照射后培养时间的增加,mtDNA 4977bp缺失拷贝数、mtDNA总拷贝数和mtDNA 4977bp缺失率均有增加趋势。培养时间为24 h和72 h时,在0～10 Gy剂量范围内mtDNA 4977bp缺失拷贝数、mtDNA总拷贝数和mtDNA 4977bp缺失率随着受照剂量的增加而增加。提示X射线诱发的mtDNA 4977bp缺失和mtDNA总拷贝数具有时间和剂量累积性。

To investigate the time-effect of mitochondfial DNA 4977bp deletion in human peripheral blood cells exposed to X ray, human peripheral whole blood samples were collected from two healthy individuals, and exposed to X rays with dose from 0 to 10 Gy. The genomic DNAs were isolated from the whole-blood samples, and the levels of mtDNA 4977bp deletion and copy number of total mtDNA in the DNA samples were detected by Real-time PCR after irradiation at 2, 12, 24, 48, and 72 h, respectively. The results showed that the copy number of mtDNA 4977bp deletion and total mtDNA, and the rates of mtDNA 4977bp deletion increase with incubation time with dose at 5 Gy after irradiation. Moreover, they increased with dose from 0 to 10 Gy after irradiation at 24 h and 72 h, respectively. The results suggested that the levels of mtDNA 4977bp deletion and the copy number of total mtDNA in human peripheral blood cells exposed to X ray were accumulated with incubation time and dose increase, respectively.