胆固醇致人血管内皮细胞DNA损伤

Cholesterol Induces DNA Damage in HUVECs

本文研究胆固醇是否通过氧化应激机制损伤人内皮细胞DNA.实验用12.5 mg/L,25mg/L,50 mg/L胆固醇作用于人内皮细胞12 h,用免疫荧光法观察到不同浓度的胆固醇均可诱导细胞内γH2AX形成焦点,随着胆固醇浓度的增加,γH2AX焦点的荧光强度也逐渐增强.利用Western印迹及流式细胞术检测到细胞内γH2AX的量和ROS水平也随胆固醇浓度增大而增加.彗星电泳实验检测到细胞内拖尾DNA量随胆固醇浓度逐渐增加,DNA损伤加重.用抗氧化剂10 mmol/L N-乙酰半胱氨酸(NAC)预作用细胞1 h后,再用50 mg/L胆固醇作用细胞12 h,细胞内γH2AX焦点的荧光强度明显减弱,γH2AX量减少,ROS的水平下降.结果表明,胆固醇可诱导人脐静脉内皮细胞中ROS升高,导致DNA损伤.

To investigate the DNA damage from oxidative stress in human umbilical vein endothelial cells（hUVECs） induced by cholesterol,the γH2AX foci were detected by immunofluorescence following cholesterol treatments at 12.5 mg/L,25 mg/L,50 mg/L for 12 hours.The results showed that formation of γH2AX foci was increased as measured by the numbers fluorescence intensity.Western bolt and flow cytometry（FCM） showed that the level of γH2AX and reactive oxygen species（ROS） increased with cholesterol doses.Using comet assay to detect DNA lesions,we found higher percentage of tailing cells as the cholesterol concentration increased.Pre-exposed to 10 mmol/L N-acetyl-6-cysteine（NAC） for 1 hour,the hUVECs treated with 50 mg/L cholesterol showed significantly reduced γH2AX foci and decreased ROS.The results indicated that cholesterol induced DNA damage in hUVECs by elevated ROS levels.