HepG2细胞胰岛素抵抗模型中脂代谢的改变

Changes of lipid metabolism in HepG2 cells model of insulin resistance

目的 :探讨胰岛素抵抗(insulin resistance,IR)对肝细胞脂代谢酶的影响。方法:用不同浓度胰岛素刺激HepG2细胞,建立肝细胞IR模型;用油红O染色观察细胞形态及胞内脂滴形成;应用甘油三酯(triglyceride,TG)检测试剂盒检测细胞中TG含量;Real-time PCR检测乙酰辅酶a羧化酶(acetyl-Co A carboxylase,ACC)、肝型脂肪酸结合蛋白(liver-type fatty acid-binding protein,L-FABP)、脂蛋白脂酶(lipoprotein lipase,LPL)、肉碱棕榈酰转移酶(carnitine palmitoyltransferase 1,CPT1)、微粒体甘油三酯转移蛋白(microsomal triglyceride transfer protein,MTP)等脂代谢相关因子及转录因子胆固醇调节元件结合蛋白-1c(sterol regulatory element-binding protein-1c,SREBP-1c)、过氧化物酶体增生物激活受体α(peroxisome proliferator activated receptorα,PPARα)的m RNA表达水平。结果 :用浓度1×10-4 mol/L的胰岛素刺激细胞36 h后形成IR。IR细胞内脂滴增多,TG含量增加;IR细胞内脂合成相关的ACC、SREBP-1c的m RNA水平较对照组升高;LPL、CPT1、MTP、PPARα的m RNA水平较对照组降低;L-FABP m RNA水平与对照组相比无差异。结论:IR通过提高肝细胞脂合成、降低脂氧化过程,导致肝细胞内脂质异常堆积。

Objective：To investigate the effects of insulin resistance on hepatic lipid metabolism. Methods：We used RPMI 1640 with different insulin concentrations to stimulate HepG2 cells,and cells were divided into the insulin resistance （IR） group and the control group. Oil red O staining was performed to observe the cell morphology and intracelluar lipid droplets. Triglyceride was detected with the triglyceride assay kit. The expression of acetyl-CoA carboxylase （ACC）,liver-type fatty acid-binding protein （L-FABP）,lipoprotein lipase（LPL）,carnitine palmitoyltransferase1 （CPT1）,microsomal triglyceride transfer protein（MTP） and transcription regulatory factors sterol regulatory element-binding protein-1c （SREBP-1c）,and peroxisome proliferator activated receptor α （PPAR α） were detected by real-time PCR. Results：HepG2 cell model of insulin resistance was induced after 1×10-4 mol/L insulin stimulated cells for 36 h. The intracelluar lipid droplets and triglyceride content were increased in the IR group than in the control group. The mRNA expressions of ACC and SREBP-1c in the IR group were higher than in the control group,and L-FABP had no significant difference compared with the control group. The mRNA expressions of LPL,CPT1,MTP and PPARα in the IR group were lower than those in the control group. Conculsion：Insulin resistance could induce abnormal lipid accumulation in HepG2 cells via increasing lipid synthesis and reducing lipid oxidation process.