白藜芦醇通过上调脂肪变性HepG2细胞Sirt3表达改善线粒体功能

目的 探讨白藜芦醇(resveratrol,RSV)对脂肪变性肝细胞线粒体功能的影响,以及沉默信息调节因子3(sirtuin 3,Sirt3)在其中的重要作用.方法 用0.2 mmol/L棕榈酸(palmitic acid,PA)处理HepG2细胞24 h建立肝细胞脂肪变性模型,再用40 μmol/L RSV和/或50 μmol/L Sirt3抑制剂3-TYP处理24 h.实验分为对照组、PA组、PA+ RSV组、PA+ RSV+ 3-TYP组、PA+ 3-TYP组.用相关试剂盒检测甘油三酯(TG)含量、沉默调节蛋白3(sirtuin 3,Sirt3)活性、ATP合酶活性、ATP生成量以及线粒体基础呼吸率,使用DCFH-DA荧光探针检测细胞活性氧(reactive oxygen species,ROS)含量,Westernblot检测Sirt3蛋白表达.Sirt3 siRNA处理HepG2细胞后再用PA和/或RSV处理,分析ROS和甘油三酯含量.结果 相对于PA组,PA+RSV组HepG2细胞的甘油三酯、ROS含量明显降低(P＜0.05),ATP合酶活性、ATP生成量和基础呼吸率明显提高(P＜0.05).而3-TYP或Sirt3 siRNA处理后,RSV的上述作用被削弱(P＜0.05).结论 RSV通过上调脂肪变性肝细胞Sirt3的表达与活性而改善其线粒体功能.

Resveratrol improves mitochondrial function via up-regulating Sirt3 in induced steatosis in HepG2 cells

Objective To explore the influence of resveratrol (RSV) on mitochondrial function in induced steatosis in hepatic cells and investigate the role of sirtuin 3 (Sirt3) in it.Methods HepG2 cells were pretreated with palmitic acid (PA,0.2 mmol/L) for 24 h to establish hepatic steatosis cell model.Then,these hepatic steatosis cells were treated with 40 μmol/L RSV and/or 50 μmol/L 3-TYP (Sirt3 inhibitor) for 24 h.Then the cells were divided into 5 groups:control group,PA group,PA + RSV group,PA + RSV + 3-TYP group,and PA + 3-TYP group,respectively.The levels of triglycerides (TG) and ATP,Sirt3 activity,ATP synthase activity and basal oxygen consumption rate were measured using relevant kits.Reactive oxygen species (ROS) content was detected by DCFH-DA fluorescence probe.The expression of Sirt3 was measured by Western blotting.Results Compared with the PA group,the levels of TG and ROS in the PA + RSV group were decreased significantly (P ＜ 0.05).On the contrary,the ATP synthase activity,ATP level and basal oxygen consumption rate were increased significantly (P ＜ 0.05).However,the effects of RSV were impaired with 3-TYP or Sirt3 siRNA treatment (P ＜ 0.05).Conclusion RSV can improve mitochondrial function by up-regulating the expression and activity of Sirt3 in steatosis in hepatic cells.