摘要:
目的 研究阿托伐他汀在炎症状态下对人肝癌细胞株HepG2细胞氧化应激和脂质积聚的影响.方法 将普通HepG2细胞分为为3组:正常组、模型组[用100 ng·mL-1肿瘤坏死因子(TNF-α)处理]及实验组(用100 ng·mL+1TNF-α +10 μmol·L-1阿托伐他汀处理),3组同时负荷100 μg·mL-1低密度脂蛋白(LDL),处理时间24h-用油红O染色测定细胞内脂质含量;以荧光定量聚合酶链式反应和免疫印迹法分别检测HepG2细胞脂肪酸合酶(FAS)、乙酰辅酶A羧化酶(ACC)和固醇调节元件结合蛋白1(SREBP1)的基因和SREBP1蛋白表达;以二氯二氢荧光素-乙酰乙酸酯(DCFH-DA)荧光探针染色检测HepG2细胞内活性氧化产物(ROS)的含量;以比色法检测HepG2细胞过氧化氢(H2O2)和丙二醛(MDA)的含量.结果 正常组与模型组SREBP1蛋白灰度值分别为1.01±0.001,1.61±0.34,这2组的SREBP1 mRNA水平分别为1.01±0.16,3.61 ±0.39,这2组的FAS的mRNA水平分别是1.03 ±0.32,1.99±0.36,这2组的ACC的mRNA水平分别是0.95±0.29,2.37±0.52.与正常组相比,模型组的细胞FAS、ACC、SREBP1的基因和SREBP1的蛋白表达明显增加,差异均有统计学意义(均P <0.05).与模型组相比,实验组的HepG2FAS、ACC、SREBP1的基因和SREBP1的蛋白灰度值分别是2.95±0.92,3.99 ±1.16,2.85 ±0.91,2.94 ±0.65,实验组的HepG2 FAS、ACC、SREBP1的基因和SREBP1的蛋白表达明显增加,差异均有统计学意义(均P<0.05).表明在炎症状态下,阿托伐他汀进一步加重了HepG2细胞内脂质的沉积.正常组、模型组与实验组的细胞ROS含量(以荧光强度代表)分别为1.00 ±0.20,1.77±0.25,3.20±0.53;正常组、模型组与实验组的H2 O2含量分别为(2.30±0.31),(4.32±0.77),(5.31±0.75) nmol·mg-1;这2组的MDA含量分别为(0.78±0.22),(1.86±0.23),(3.43±1.15)nmol·mg-1,与正常组比较,模型组差异均有统计学意义(均P <0.05);与模型组比较,实验组差异均有统计学意义(均P <0.05).结论 在炎症状态下,阿托伐他汀诱导HepG2细胞氧化应激,激活SREBP1/FAS/ACC通路,加重细胞内脂质积聚.%Objective To investigate the effect of atorvastatin on oxidative stress and intracellular lipid accumulation in HepG2 cells under inflammatory state and explore the underlying mechanism.Methods HepG2 cells were treated with 100 ng · mL-1 TNF-α,100 ng · mL-1 TNF-α ± 10 μmol · L-1 atorvastatin in the presence of LDL for 24 h.Oil red O staining was used to examine the intracellular lipid contents.The mRNA and protein expressions of lipogenic genes (FAS,ACC and SREBP1) were detected by real-time polymerase chain reaction and Western blot.ROS levels were measured with the fluorescent probe of DCFH-DA.Contents of H2O2 and MDA were determined using the colorimetric method.Results Compared with normal group(the gray value of SREBP1 was 1.01 ± 0.001),the gray value of SREBP1 in model group was 1.61 ± 0.34.The mRNA levels in normal group of SREBP1,FAS,ACC respectively were 1.01 ± 0.16,1.03 ± 0.32,0.95 ± 0.29,the values in model group respectively were 3.61 ± 0.39,1.99 ± 0.36,2.37 ± 0.52,the differences were statistically significantly (P < 0.05).Compared with model group,the mRNA levels of SREBP1,FAS,ACC and the gray value of SREBP1 in experimental group respectively were 2.95 ± 0.92,3.99 ± 1.16,2.85 ± 0.91,2.94 ± 0.65,the differences were statistically significantly(P <0.05).At the same time,compared with normal group,the levels of ROS(fluorescenceintensity),H2O2,MDA respectively were 1.00 ±0.20,and (2.30 ±0.31) (0.78 ±0.22) nmol · mg-1,the levels in model group respectively were 1.77 ± 0.25 and (4.32 ± 0.77),(1.86 ± 0.23) nmol · mg-1,the differences were statistically significantly (P < 0.05).Compared with model group,the levels of ROS,H2 O2,MDA in HepG2 cells in experimental group respectively were 3.2 ±0.53 and (5.31 ±0.75),(3.43 ± 1.15) nmol · mg-1,the differences were statistically significantly(P < 0.05).Conclusion Atorvastatin induced intracellular lipid accumulation in HepG2 cells under inflammatory stress,which may be associated with the increased oxidative stress.