论文部分内容阅读
目的建立地塞米松(DEX)诱导的大鼠骨骼肌细胞胰岛素抵抗模型,并观察表没食子儿茶素没食子酸酯(EGCG)对其的保护作用。方法分化好的L6肌细胞,以1μmol/LDEX诱导L6肌细胞产生胰岛素抵抗,予以不同浓度的EGCG进行干预24h。然后分别用葡萄糖消耗实验、葡萄糖转运实验检测胰岛素刺激下L6细胞对葡萄糖的消耗和利用情况,Westernblot检测细胞胰岛素受体底物-1(IRS-1)的蛋白表达水平。结果与100nmol/L胰岛素组比较,1μmol/LDEX作用24h后胰岛素刺激下细胞上清液中葡萄糖的残存量显著增加和细胞内葡萄糖转运量明显减少(P<0.05),而EGCG作用后明显改善DEX的抑制作用(P<0.05),并呈剂量反应关系。Westernblot结果显示,与胰岛素组相比,DEX增高IRS-1的Ser307磷酸化表达,而EGCG作用后减少IRS-1的Ser307磷酸化表达。结论本研究表明,1μmol/LDEX作用24h能诱导L6肌细胞的胰岛素抵抗,而EGCG能改善这种胰岛素抵抗,可能是通过减少IRS-1的Ser307磷酸化表达来实现的。
Objective To establish a model of insulin resistance induced by dexamethasone (DEX) in rat skeletal muscle cells and observe the protective effect of epigallocatechin gallate (EGCG) on it. Methods Differentiated L6 myocytes were induced with 1 μmol / L LDEX to induce insulin resistance in L6 myocytes and treated with different concentrations of EGCG for 24 h. Then glucose depletion and glucose transport were used to detect the glucose consumption and utilization of L6 cells stimulated by insulin. Western blot was used to detect the protein expression of insulin receptor substrate-1 (IRS-1). Results Compared with the 100 nmol / L insulin group, the glucose remnant and cytosolic glucose transport in the supernatant of the cells stimulated by 1 μmol / L LDH for 24 h were significantly increased (P <0.05), while the changes of DEX (P <0.05), and the dose-response relationship. Western blot analysis showed that DEX increased Ser307 phosphorylation of IRS-1 compared with insulin group, whereas EGCG decreased Ser307 phosphorylation of IRS-1. Conclusions This study shows that 1 μmol / L LDEX can induce insulin resistance in L6 myocytes. However, EGCG can improve this insulin resistance by reducing the phosphorylation of Ser307 in IRS-1.