SCD1过表达影响高脂诱导鼠BRL肝细胞膜电位变化研究

目的探讨硬脂酰辅酶A去饱和酶1（SCD1）过表达影响大鼠BRL肝细胞系凋亡作用的可能机制。方法通过台盼兰染色检测不同浓度棕榈酸（PA）诱导BRL肝细胞死亡率确定下游实验PA添加浓度。培养细胞分组为非加药组和加药组。非加药组包括一般培养组（CON）、一般培养加阴性病毒组（NC）及一般培养加过表达病毒组（SCD1-LV）;加药组包括一般培养加PA组（CON＋）、一般培养加阴性病毒和PA组（NC＋）及一般培养加过表达病毒和PA组（SCD1-LV＋）。实时荧光定量聚合酶链反应（PCR）检测SCD1 mRNA表达的变化,流式细胞术测细胞线粒体膜电位（MMP）的变化,用膜电位正常细胞百分比（JC-1＋%）表示MMP改变。结果与对照组相比,400μmol/L PA诱导72 h细胞死亡率明显上升（P〈0.01）。PA诱导引起CON＋及NC＋组SCD1表达下降,SCD1-LV＋组及SCD1-LV组SCD1表达明显上升;CON＋和NC＋组JC-1＋%较低,SCD1-LV＋组JC-1＋%与对照组相似。结论用SCD1慢病毒载体感染BRL肝细胞系,SCD1表达升高,增强细胞对饱和脂肪酸的去饱和作用,过表达SCD1能降低PA诱导的脂毒性,使紊乱的MMP得到恢复。

Research on the overexpression of SCD1 affecting the change of mitochondrium membrane potential in rat BRL hepatocytes caused by fat-rich diet induction

Objective To investigate the mechanism of stearoyl-CoA desaturase-1（SCD1） overexpression affecting the apoptosis of rat BRL hepatocytes induced by a fat-rich diet.Methods The death rates of BRL hepatocytes under different palmitic acid（PA） concentrations were detected by Trypan blue staining.The concentration of PA was certained for the following determination.Cultured cells were classified into two groups（no-PA added group and PA added group）.No-PA added group included cultured ordinary group（CON）,CON plus negative virus cultured group（NC） and CON plus SCD1 overexpression virus cultured group（SCD1-LV）.PA added group included PA plus cultured ordinary group（CON＋）,CON plus negative virus and PA cultured group（NC＋）,and CON plus SCD1 overexpression virus and PA cultured group（SCD1-LV＋）.SCD1 mRNA expression was detected by real time polymerase chain reaction（PCR）.The changes of mitochondrium membrane potential（MMP） were detected by flow cytometry.The percentage of BRL hepatocytes of normal membrane potential（5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide ＋%,JC-1＋%） was used to indicate the change of normal MMP.Results The death rate of BRL hepatocytes increased significantly after 72 h induced by 400 μmol/L PA.PA decreased the expression of SCD1 in CON＋ group and NC＋ group,but it increased the expression in SCD1-LV＋group and SCD1-LV group.JC-1＋% was lower in CON＋ and NC＋ groups,but JC-1＋% in SCD1-LV＋ group was similar to that in control group.Conclusions The expression of SCD1 increases in BRL hepatocytes when they are infected by SCD1 overexpression lentiviral vector.The destaturation of saturated fatty acid is enhanced.Overexpression of SCD1 decreases the toxicity induced by PA.The MMP disorder of infected BRL hepatocytes is retrieved.