大剂量γ射线照射后PC12细胞死亡方式的研究

Preliminary research on death pattern in PC12 cell after high-dose of gamma-ray irradiation

目的研究受大剂量γ射线作用后,大鼠肾上腺嗜铬细胞瘤细胞(PC12)的死亡方式,寻找神经细胞辐射损伤的体外模型。方法PC12细胞分为0、8、16和32Gy组,经60Coγ射线照射后,PI单染流式细胞术法观察细胞增殖周期改变,Annexin-V-FITC及PI双染法检测细胞凋亡的发生,光镜和电镜技术观察照射后细胞分化与存活的形态学变化。结果大剂量γ射线照射后,随照射剂量的加大,发生死亡的细胞数有所增加,但发生凋亡的PC12细胞数目很少,可以忽略不计;细胞主要是在肿胀的基础上发生死亡的。电镜显示,细胞器明显肿胀扩张,粗面内质网高度扩张,线粒体肿胀、空化,核染色质浓缩成块状,散在于核膜下及核仁周围,核膜间隙增宽,与胀亡性坏死的特征相类似。结论大剂量γ射线照射后,PC12细胞主要是在肿胀的基础上发生死亡的。该细胞模型适于被用来研究辐射致神经细胞坏死相关病理生理过程及其内在机制等问题。

Objective To investigate the death pattern of pheochromocyoma cell line （PC12 cell） irradiated with ionizing radiation and to search for a model of radiation-induced neuron injury in vitro. Methods PC12 cell was irradiated with different doses of 60^ Co γ-rays. The effect of radiation on cell cycle, development, differentiation and death rate were detected by flow cytometry, light microscope, and transmission electron microscope （TEM）. Results Irradiated PC12 cell showed cell cycle retardation and differentiation, but some cells died due to swelling. Apoptosis was observed in few cells. TEM examination indicated that mitochondrion and endoplasmic reticulum were dilated markedly, chromatin was concentrated and scattered near karyotheca or around the nucleolus, which characterized oncosis. Conclusions PC12 cell died through oncosis after gamma-ray irradiation of high-dose, and can be used as a radiation-induced neuron injury model.