解偶联蛋白2过表达张氏肝细胞的构建及其对线粒体膜电位和活性氧的影响

目的 构建稳定过表达人解偶联蛋白2 (UCP2)的张氏肝细胞株,观察UCP2对线粒体膜电位(MMP)和活性氧(ROS)的作用. 方法 将含有人UCP2 cDNA全长的重组质粒(pcDNA3.1-hU CP2)转染张氏肝细胞系,pcDNA3.1空载体作为对照.Zeocin筛选稳定表达UCP2的细胞株,Western blot和免疫细胞化学鉴定UCP2蛋白表达.利用不同剂量UCP2抑制剂京尼平(25、50、100μmol/L),预处理稳定表达UCP2的细胞株.荧光分光光度法检测MMP和ROS水平变化.数据分析用单因素方差分析和q检验(Newman-keuls法),P＜0.05为差异有统计学意义.结果 pcDNA3.1-hU CP2成功转染张氏肝细胞,UCP2相对表达量约为对照组的1.6倍.过表达细胞罗丹明123和2 ′,7 ′ -二氯氢化荧光素二脂荧光强度(分别为11.11±2.76和4.97±0.62)均明显低于正常对照组张氏肝细胞(分别为15.56±2.55和6.14±1.25,q值分别为4.80和3.35,P＜0.01和P＜ 0.05)和空载体对照组肝细胞(分别为16.11±2.93和6.23±1.13,q值分别为5.40和3.60,P＜0.01和P＜ 0.05);空载体组上述两指标与正常对照组相比,差异均无统计学意义.京尼平低、中、高剂量组与过表达组相比,罗丹明123的荧光强度(分别为14.89±2.89,17.89±2.93,24.00±2.55,q值分别为4.08,7.33和13.93,P值均＜0.01)和2 ′,7 ′-二氯氢化荧光素二脂的荧光强度(分别为9.16±0.78,10.84±1.09, 11.83±1.25,q值分别为12.00,16.83和19.67,P值均＜0.01)均明显升高,并呈现剂量依赖性.结论 成功构建稳定过表达人U CP2的张氏肝细胞株,UCP2表达水平及活性变化可通过MMP和ROS影响线粒体功能.

Establishment of the Chang liver cell line stably overexpressing human UCP2 gene and its effect on mitochondrial membrane potential and reactive oxygen species

To establish the Chang liver cell line stably overexpressing human uncoupling protein 2 (UCP2) and observe the effect of UCP2 on mitochondrial membrane potential (MMP) and reactive oxygen species (ROS). The Chang liver cell line was transfected with recombinant plasmid containing full-length human UCP2 cDNA (pcDNA3.1-hUCP2) or pcDNA3.1 empty vector. The stable cell line was established by antibiotic screening with Zeocin. UCP2 expression was detected by Western blotting and immunocytochemistry. The UCP2 overexpressing cells were pretreated with genipin at various doses (25, 50 and 100 munol/L). MMP and intracellular ROS were detected by fluorescence spectrophotometry. The total normalized protein content in UCP2 overexpressing cells was 1.6-fold higher than that in unmanipulated normal cells. The fluorescence intensities of Rhodamine123 and DCFH-DA in UCP2 overexpressing Chang liver cells (11.11+/-2.76 and 4.97+/-0.62, respectively) were significantly lower than those in unmanipulated normal cells (15.56+/-2.55, P less than 0.01 and 6.14+/-1.25, P less than 0.05, respectively) and in cells transfected with empty vector (16.11+/-2.93, P less than 0.01 and 6.23+/-1.13, P less than 0.05, respectively). Treatment of UCP2 overexpressing cells with 25, 50 and 100 munol/L genipin caused a dose-dependent increase in fluorescence intensities of Rhodamine123 (14.89+/-2.89, 17.89+/-2.93 and 24.00+/-2.55, respectively, all P less than 0.01) and DCFH-DA (9.16+/-0.78, 10.84+/-1.09 and 11.83+/-1.25, respectively, all P less than 0.01). The Chang liver cell line stably overexpressing UCP2 was established successfully. Using this cell system, UCP2 was found to play a role in mitochondrial function by regulating MMP and ROS.