The effect of target-directed regulation of the uncoupling protein-2 （UCP-2） gene expression on the ischemia-reperfusion injury of hepatocytes under different conditions was investigated. The expression plasmid and RNAi plasmid targeting UCP-2 gene were constructed and trans- fected into normal hepatocytes and fatty liver cells, respectively. The expression of UCP-2 mRNA was detected by real time PCR. The cells were divided into normal cell group （NCG）, group of normal cells transfected with empty vector （EVNCG）, group of normal cells transfected with expression plasmid （EPNCG）, fatty liver cell group （FCG） and group of fatty liver cells transfected with RNAi plasmid （RPFCG）. The ischemia-reperfusion model in vitro was established. One, 6, 12 and 24 h after reperfusion, Annexin V/PI flow cytometry was used to measure cell necrosis rate, apoptosis rate and survival rate. Simultaneously, the intracellular ATP, ROS and MDA levels were determined. The re- sults showed that 1, 6, 12 and 24 h after ischemia-reperfusion, the intracellular ROS, MDA and ATP levels and cell survival rate in EPNCG were significantly lower, and cell necrosis rate significantly higher than in NCG and EVNCG, but there was no significant difference in apoptosis rate among NCG, EVNCG and EPNCG （P〉005）. Six, 12 and 24 h after reperfusion there was no significant dif- ference in ROS, MDA levels and apoptosis rate between FCG and RPFCG （P〉0.05）, but the ATP level and survival rate of cells in RPFCG were higher than in FCG （P〈0.05）. It was concluded that down-regulation of the UCP-2 gene expression in steatotic hepatocytes could alleviate the ische- mia-reperfusion injury of liver cells.
目的研究解偶联蛋白-2(uncoupling protein-2,UCP-2)基因在肝细胞急性损伤过程中的作用。方法构建小鼠UCP-2基因过表达慢病毒载体;二步胶原酶灌注法分离培养小鼠原代肝细胞;慢病毒感染肝细胞,使肝细胞中UCP-2基因表达上调;荧光显微镜镜检确定感染效率,Real ti me PCR检测UCP-2表达;肿瘤坏死因子-α(TNF-α)作用于病毒感染肝细胞24 h后,检测细胞上清液中谷丙转氨酶(ALT)和乳酸脱氢酶(LDH)水平;碘化丙啶(PI)染色流式细胞仪检测细胞凋亡,Western blot检测凋亡因子Caspase 3的活化。结果Real ti me PCR检测证实目的细胞中UCP-2表达上调;TNF-α作用后病毒感染的实验组上清液中ALT和LDH水平、细胞凋亡率、凋亡因子Caspase 3活化程度均高于对照组(均P<0.05)。结论UCP-2基因过度表达可加重肝细胞急性损伤。
