成纤维细胞生长因子-21改善胰岛素抵抗肝细胞对葡萄糖的吸收及机制

摘要

目的 建立正常人肝细胞(HL-7702)胰岛素抵抗(insulin resistance,IR)模型,探讨成纤维细胞生长因子-21(FGF-21)对胰岛素抵抗的改善作用及其机制.方法 培养HL-7702细胞,利用高浓度胰岛素和地塞米松(dexamethasone,DEX)诱导IR模型.GOD-POD试剂盒测定细胞葡萄糖消耗量,Western blot检测GLUT1和磷酸化ERK1/2表达水平.结果 FGF-21促进HL-7702细胞葡萄糖的消耗且呈剂量依赖性,与胰岛素联合用药提高葡萄糖消耗量.在随后IR模型实验中,FGF-21改善IR模型细胞葡萄糖消耗量.FGF-21作用24 h,GLUT1的表达量明显增高,p-ERK1/2的含量增强.当加入ERK1/2特异性抑制剂PD98059,FGF-21促ERK1/2的磷酸化作用被抑制.IR模型中,FGF-21仍能提高p-ERK1/2的含量.结论 FGF-21促进HL-7702细胞对葡萄糖的消耗,改善IR HL-7702细胞葡萄糖消耗量,提高葡萄糖转运蛋白GLUT1和ERK1/2磷酸化的表达.%Aim To establish an insulin resistance cell model and evaluate the effects of FGF-21 on insulin resistance. Methods Human liver cells were administrated by high concentration of Dexamethasone and insulin. Glucose uptake activity of FGF-21 was examined by glucose oxidase and peroxidase( GOD-POD ) assay. The expressions of GLUT1 and the ERK1/2 signaling pathway were examined by Western blot. Results FGF-21 could stimulate glucose uptake of HL-7702 cells in a dose-dependent manner, suggesting that theglucose uptake assay was valid. Glucose uptake of HL-7702 cells stimulated by the mixture of FGF-21 and insulin was higher than that by FGF-21 or insulin solely. The FGF-21 protein was subsequently tested in IR cell models, showing that it could also stimulate glucose uptake of HL-7702 cells. The expressions of GLUT1 and the phosphorylation of ERK1/2 increased with the administration of FGF-21. The phosphorylation of ERK1/ 2 stimulated by FGF-21 was inhibited when PD98059, the specific inhibitor of ERK1/2, was added into thecell supernatant. In the IR model, FGF-21 could still increase the content of p-ERKl/2. Conclusions FGF-21 can stimulate glucose uptake of HL-7702 cells in a dose-dependent manner, and stimulate the glucose uptake of IR cell models. FGF-21 increases the ex-pression of GLUT1 and the phosphorylation of ERK1/2.