芒果苷对胰岛素抵抗HepG2细胞糖脂代谢的影响

目的:分析芒果苷(MGF)对胰岛素抵抗HepG2细胞(IR-HepG2细胞)糖脂代谢的影响,并探讨潜在机制。方法:以人肝癌HepG2细胞为对象,以1 mmol/L棕榈酸+2 mmol/L油酸联合培养建立IR-HepG2细胞模型。以盐酸二甲双胍为阳性对照,分别检测低、中、高浓度MGF(125、250、500μmol/L)作用24 h对IR-HepG2细胞中校正葡萄糖耗氧量和三酰甘油(TG)、总胆固醇(TC)含量的影响;采用实时荧光定量聚合酶链式反应技术检测细胞中腺苷一磷酸活化蛋白激酶(AMPK)通路上游关键因子脂联素(APN)、脂联素受体2(AdipoR2)、APPL1、AMPK以及下游胰岛素信号通路关键因子胰岛素受体底物1(IRS-1)、蛋白激酶B(Akt)、葡萄糖转运体4(GLUT4)mRNA的相对表达量;采用Western blot法检测AMPK蛋白的磷酸化水平。结果:与对照组比较,模型组细胞校正葡萄糖消耗量和APN、AdipoR2、APPL1、AMPK、IRS-1、GLUT4 mRNA的相对表达量以及AMPK蛋白磷酸化水平均显著降低,TG、TC含量均显著升高(P<0.05或P<0.01);与模型组比较,各药物组校正葡萄糖消耗量和APN(MGF中、高浓度组除外)、AdipoR2、APPL1、AMPK(MGF中、高浓度组除外)、IRS-1(MGF中、高浓度组除外)、Akt(阳性对照组除外)、GLUT4(MGF高浓度组除外)mRNA的相对表达量以及AMPK蛋白磷酸化水平均显著升高,TG、TC含量均显著降低(P<0.05或P<0.01)。结论:芒果苷可能通过激活通路上游靶点APN,进而调控AMPK信号通路,从而促进IR-HepG2细胞对葡萄糖的摄取,降低TG、TC含量,发挥改善胰岛素抵抗及糖脂代谢异常状态的作用。

Effects of Mangiferin on Glucose and Lipid Metabolism of Insulin-resistant HepG2 Cells

OBJECTIVE:To analyze the effects of mangiferin(MGF)on glucose and lipid metabolism in insulin resistance(IR)HepG2 cells,and to explore the potential mechanism.METHODS:Using human hepatoma HepG2 cells as research objects,1 mmol/L palmitic acid and 2 mmol/L oleic acid were used to establish the IR-HepG2 cell model.Using metformin hydrochloride as positive control,the effects of low-concentration,medium-concentration and high-concentration MGF(125,250,500μmol/L)on the corrected glucose consumption,the contents of triglyceride(TG)and total cholesterol(TC)in IR-HepG2 cells were detected.The mRNA expression of APN,AdipoR2,APPL1,AMPK in the upstream of AMPK signaling pathway and IRS-1,Akt and GLUT4 in the downstream insulin signaling pathway were detected by RT-PCR.The phosphorylation level of AMPK protein was detected by Western blot assay.RESULTS:Compared with control group,corrected glucose consumption,mRNA expression of APN,AdipoR2,APPL1,AMPK,IRS-1 and GLUT4,as well as the phosphorylation level of AMPK protein were decreased significantly in model group,while the contents of TG and TC were increased significantly(P<0.05 or P<0.01).Compared with model group,corrected glucose consumption,mRNA expression of APN(except for MGF medium-concentration and high-concentration groups),AdipoR2,APPL1,AMPK(except for MGF medium-concentration and high-concentration groups),IRS-1(except for MGF medium-concentration and high-concentration groups),Akt(except for positive control group),GLUT4(except for MGF high-concentration group)were increased significantly in administration groups,while the contents of TG and TC were decreased significantly(P<0.05 or P<0.01).CONCLUSIONS:Mangiferin may activate APN,which is the upstream target of pathway,and then regulate AMPK signaling pathway,so as to promote glucose uptake of IR-HepG2 cells,reduce TG and TC contents,and improve IR and abnormal glucose and lipid metabolism.