X射线照射对人脐静脉内皮细胞焦亡的影响

目的：探讨X射线照射对人脐静脉内皮细胞（HUVEC）焦亡的影响。方法：单次10 Gy X射线照射HUVEC细胞，采用ELISA法检测照射后0~72 h HUVEC分泌细胞因子IL-1β、IL-6、TNF-α和IL-18的浓度，Western blot法检测照射后6~48 h HUVEC内Caspase-1的活化水平，采用透射电子显微镜检测照射后72 h HUVEC形态的变化。采用流式细胞术检测单次10 Gy以及多次小剂量（2.5 Gy/d，连续4 d）照射后HUVEC焦亡率的变化。结果：10 Gy X射线照射后0~72 h HUVEC中IL-1β、IL-6、TNF-α和IL-18浓度与对照组（0 Gy组）相比均明显升高（P<0.05）。10 Gy X射线照射后6~48 h细胞内Caspase-1活化水平升高（P<0.05），细胞呈现体积增大肿胀状态。单次10 Gy照射组和多次小剂量照射组细胞焦亡率均明显高于空白对照组（P<0.01）；此外，单次10 Gy照射组细胞焦亡率较多次小剂量照射组细胞升高约1倍（P<0.01）。结论：X射线照射可引起人脐静脉内皮细胞HUVEC焦亡；在总剂量相同情况下，单次大剂量照射引起的HUVEC焦亡水平明显高于多次小剂量照射。

Induction of pyroptosis by X-rays in human umbilical vein endothelial cells

OBJECTIVE: To investigate the effects of X-ray irradiation on pyroptosis of human umbilical vein endothelial cells (HUVEC). METHODS: Pyroptosis is an inflammatory programmed cell death process. Cells were irradiated with a single dose of 10 Gy X-ray. In order to investigate the occurrence of X-ray induced pyroptosis,levels of IL-1 β,IL-6,TNF-α and IL-18 which were secreted by HUVEC cells from 0 to 72 h after the radiation were determined using the ELISA assay. Caspase-1 which is cleaved to the activated state is a key step of pyroptosis. Therefore,the activated levels of Caspase-1 were detected using Western blot at 6-48 h after the single dose of 10 Gy X-ray irradiation. Morphological changes of HUVECs were detected using transmission electron microscopy (TEM) at 72 h after the irradiation. Flow cytometry (FCM) was used to detect the changes of pyroptosis after a single dose and a small dose of multiple exposures (2.5 Gy/d×4 d). RESULTS: Compared with the control group,the levels of IL-1 β,IL-6,TNF-α and IL-18 in HUVEC cells 0-72 h after the radiation were significantly higher (P<0.05) and the levels of activated Caspase-1 at 6-48 h after the radiation was increased (P<0.05). The cell volumes were increased with swelling. The percentages of pyroptoti cells after the single and multiple exposures were significantly higher than that of the control group (P<0.01). In addition,the pyroptotic death rates after the single dose was twice as high as that after the multiple doses (P<0.01). CONCLUSION: X-ray exposure induced pyroptosis in HUVEC cells. Under the same total dose,the damage levels from the single dose exposure were significantly higher than that from the multiple exposures.