芒果苷改善高果糖所致HepG2细胞内甘油三酯沉积机制研究

Mangiferin ameliorates high-fructose-induced triglyceride deposition in HepG2 cells

目的研究芒果苷改善高果糖诱导的Hep G2细胞内甘油三酯沉积的可能机制。方法低糖(1 g/L葡萄糖)条件下培养的Hep G2细胞分为对照组(1 g/L葡萄糖,无果糖)、果糖组(1 g/L葡萄糖+30 mmol/L果糖)、果糖+芒果苷组(同时加入葡萄糖浓度1 g/L+30 mmol/L果糖+不同剂量的芒果苷,使其药物终浓度分别为6.25、12.5、25、50μmol/L),药物干预24 h之后,油红O染色观察细胞内脂滴的沉积情况,酶法测定细胞内甘油三酯(TG)的含量,Real-time PCR检测碳水化合物反应元件结合蛋白(ChREBP)、固醇调节元件结合蛋白1c(SREBP-1c)、肝型丙酮酸激酶(LPK)、二酯酰甘油酰基转移酶2(DGAT-2)mRNA表达的变化。结果油红O染色结果显示,与对照组相比,果糖组的Hep G2细胞脂滴显著增多,细胞内TG含量也明显升高(P<0.05)。与果糖组对比,低剂量的芒果苷对果糖导致的细胞内脂滴的沉积无影响,较高剂量的芒果苷(25μmol/L和50μmol/L)使细胞内的脂滴数量明显减少,细胞内TG含量显著降低(P<0.05),以50μmol/L的芒果苷干预效果最好。Real-time PCR结果显示,与对照组相比,果糖组Hep G2细胞ChREBP、SREBP-1c、LPK、DGAT-2 mRNA明显升高,50μmol/L芒果苷能够下调Hep G2细胞ChREBP、LPK、DGAT-2 mRNA的高表达(P<0.05),但对SREBP-1c mRNA表达影响不明显。结论芒果苷能够改善高果糖诱导的Hep G2细胞内TG的沉积,可能与抑制脂质合成相关基因ChREBP、LPK、DGAT-2 mRNA的表达密切相关。

Objective To investigate the possible mechanism of mangiferin in ameliorating highfructose-induced triglyceride（ TG） deposition in Hep G2 cells. Methods Hep G2 cells were cultured in Dulbecco minimum essential medium with low fructose concentration（ 1 g / L glucose）,and then the cells were divided into control group（ no fructose）,fructose group（ 30 mmol / L fructose）,and fructose ＋ mangiferin groups with different concentrations（ 6. 25,12. 5,25 and 50 μmol / L） of mangiferin. After intervention for24 h,the lipid droplet deposition was observed by oil red O staining,and the content of triglyceride was detected by enzymatic method. Real-time PCR was used to determine the mRNA expression of carbohydrate response element binding protein（ ChREBP）,sterol regulatory element binding protein-1c（ SREBP-1c）,liver pyruvate kinase（ LPK） and diacylglycerol acyltransferase-2（ DGAT-2）. Results Compared with the control group,Hep G2 cells in the fructose group showed more lipid droplets and higher TG content（ P〈0. 05）. Compared with the fructose group,low doses of mangiferin had no effect on the lipid droplet deposition caused by fructose,while high doses of mangiferin（ 25 and 50 μmol / L） decreased lipid droplets and TG content significantly（ P〈0. 05）,of which 50 μmol / L mangiferin exhibited the best intervention effect. Realtime PCR result showed that,compared with the control group,the mRNA expressions of ChREBP,SREBP-1c,LPK,and DGAT-2 increased significantly in the fructose group. Although 50 μmol / L mangiferin could down-regulate the mRNA expressions of ChREBP,LPK,and DGAT-2（ P〈0. 05）,it showed minimal effect on SREBP-1c mRNA expression. Conclusion Mangiferin ameliorates high-fructose-induced TG deposition in Hep G2 cells through inhibiting over-expressions of lipid synthesis related genes including ChREBP,LPK and DGAT-2.