黄连素通过调节磷脂酰肌醇-3-激酶/丝氨酸/苏氨酸激酶/葡萄糖转运蛋白4信号途径改善胰岛素抵抗的机制研究

Berberine improves insulin resistance by regulating the serine/threonine kinase and glucose transporter 4 signaling pathway

目的研究黄连素对胰岛素抵抗细胞3T3-L1细胞磷脂酰肌醇-3-激酶/丝氨酸/苏氨酸激酶(AKT)和葡萄糖转运蛋白4(GLUT4)mRNA和蛋白表达的影响,探讨黄连素改善胰岛素抵抗的分子机制。方法将3T3-L1脂肪细胞随机分为正常对照组、胰岛素抵抗、黄连素3组,应用地塞米松诱导细胞胰岛素抵抗,黄连素组同时加入黄连素。以葡萄糖氧化酶法测定3组细胞上清液中葡萄糖消耗量,观察黄连素对脂肪细胞葡萄糖摄取的影响;应用免疫印迹技术(Western blotting)技术测定脂肪细胞AKT和GLUT4的蛋白水平变化;应用实时荧光定量PCR技术检测脂肪细胞AKT和GLUT4的mRNA表达变化。结果与正常对照组相比,胰岛素抵抗组的AKT和GLUT4 mRNA和蛋白表达明显下降(P<0.05),经黄连素干预后,AKT和GLUT4 mRNA和蛋白表达水平有一定升高,但仍显著低于正常对照组(P<0.05)。结论黄连素通过上调AKT基因和蛋白的表达进而增加GLUT4的水平,改善胰岛素抵抗状态。

Objective To investigate the effects of berberine on the m RNA and protein expressions of AKT and GLUT4 in insulin-resistant 3 T3-L1 cells, and to explore the molecular mechanism by which berberine improves in-sulin resistance. Methods 3 T3-L1 adipocytes were randomly divided into control group, insulin resistance group and berberine group. For the latter two groups, insulin resistance was induced by using dexamethasone; berberine was added to the berberine group. The effects of berberine on glucose uptake by adipocytes were determined by measuring the residual glucose in the supernatant of the three groups. The protein levels of AKT and GLUT4 were determined by Western blotting. Real-time fluorescence quantitative PCR was used to detect the m RNA expression of AKT and GLUT4 in adipocytes. Results Compared with the control group, the m RNA and protein expressions of AKT and GLUT4 were significantly reduced in the insulin resistance group（P〈0.05）. The m RNA and protein levels of AKT and GLUT4 were increased after berberine intervention, yet still significantly lower than those in the control group（ P〈0.05）. Conclusion Berberine is involved in glucose metabolism by up-regulating the protein and m RNA expressions of AKT and GLUT4 in insulin-resistant 3 T3-L1 adipocytes.