电离辐射诱导小鼠胸腺细胞G1期阻滞的分子调控初探

目的研究电离辐射诱导小鼠胸腺细胞Ｇ１期阻滞的分子通路。方法ＰＩ染色，流式细胞术检测细胞周期。单克隆抗体免疫荧光标记，流式细胞术检测蛋白表达。结果０５、１．０及２．０ＧｙＸ射线全身照射后１２小时及２．０Ｇｙ照射后２４小时小鼠胸腺细胞Ｇ１期细胞数明显增高。２．０Ｇｙ照射后ｐ５３蛋白表达在照射后１～８小时明显增高；ｐ２１蛋白表达在照射后４～４８小时明显增高；ＭＤＭ２蛋白表达在照射后４小时及８小时明显增高；而ＧＡＤＤ４５蛋白表达未见明显变化。结论０５～２．０ＧｙＸ射线全身照射可诱导小鼠胸腺细胞Ｇ１期阻滞。其分子通路主要是ｐ５３－ｐ２１通路。

Molecular pathway of G1 arrest of thymocytes induced by ionizing radiation

Objective\ To investigate the molecular pathway of G1 arrest of thymocytes induced by ionizing radiation. Methods Flow cytometry (FCM) was used to analyze cell cycle stained with propidium iodide (PI).And FCM was also used to analyze protein expression of thymocytes for their immunofluorescence stained with monoclonal antibodies. Results It was found that G1 phase cells of thymocytes increased significantly 12 h after whole body irradiation (WBI) with doses of 05,10 and 20 Gy,and 24 h following 2 Gy WBI in mice.The results also showed the increases of p53 cells of thymocytes at 1 h to 8 h,p21 cells at 4 h to 48 h,and MDM2 cells at 4 h and 8 h after 2 Gy WBI in mice.But no change was found in GADD45 cells. Conclusion Z]G1 arrest could be induced by single WBI with 05 Gy to 20 Gy Xrays,and its molecular control might be established through the p53-p21 pathway.