Vaspin通过胰岛素信号通路改善地塞米松诱导的3T3-L1脂肪细胞的胰岛素抵抗
Vaspin improves dexamethasone-induced insulin resistance of 3T3-L1 adipocytes via insulin signaling pathway

摘要：目的 探讨Vaspin对胰岛素抵抗脂肪细胞3T3-L1信号通路的作用及其机制。方法 前脂肪细胞3T3-L1经地塞米松、IBMX及胰岛素混合诱导剂诱导8d，分化成为成熟脂肪细胞。①不同质量浓度Vaspin(0、50、100、200ng/mL)处理成熟3T3-L1细胞，观察PAKT/AKT通路的变化。②采用1μmol/L 地塞米松建立胰岛素抵抗模型。分化成熟的脂肪细胞随机分为4组：对照组、模型对照组、实验组、Vaspin 200ng/mL+wortmannin 100nmol/L组。③观察Vaspin作用不同时间对胰岛素抵抗脂肪细胞葡萄糖消耗量的影响，Western blot分析胰岛素信号通路IRS-1、磷脂酰肌醇3激酶(PI3K)及Akt/phospho-Akt蛋白表达。结果 ①Vaspin(0、50、100、200ng/mL)干预成熟脂肪细胞12h，Vaspin以浓度依赖的方式增加PAKT蛋白表达，与对照组相比，在100、200ng/mL组均有统计学差异(P<0.01)。②实验组葡萄糖消耗量均高于模型对照组(P<0.05)；对照组与实验组比较，葡萄糖消耗量没有统计学差异(P>0.05)。③与对照组相比，模型对照组的IRS-1、PI3K、PAKT的蛋白表达低于对照组，差异有统计学意义(P<0.01)；与模型对照组相比，实验组IRS-1、PI3K、PAKT的蛋白表达量均上调，差异有统计学意义(P<0.01)；wortmannin预处理则阻断了Vaspin对PAKT/AKT、PI3K、IRS-1蛋白表达的上调。结论 Vaspin通过影响胰岛素抵抗的脂肪细胞中的PAKT/AKT胰岛素信号通路，增加葡萄糖的利用，改善了地塞米松诱导的3T3-L1脂肪细胞的胰岛素抵抗。
ABSTRACT: Objective To observe the effects of Vaspin on signal pathway of insulin-resistant 3T3-L1 adipocytes to further discuss the mechanism of Vaspin. Methods 3T3-L1 preadipocytes were induced for 8 days by mixed inducer of dexamethasone, IBMX and insulin. Then they were differentiated into mature adipocytes. ① Different concentrations of Vaspin (0, 50, 100 and 200ng/mL) were used to treat mature 3T3-L1 adipocytes and the changes in PAKT/AKT pathway were observed. ② Dexamethasone of 1μmol/L was used to establish insulin resistance model; glucose oxidase method was used to measure glucose concentration in cell culture supernatant; the establishment of insulin resistance model was confirmed. ③ The effect of Vaspin on glucose consumption of insulin-resistant adipocytes during different time was observed; Western blotting test was used to analyze the expressions of insulin signaling pathway IRS-1, PI3K and Akt/phospho-Akt protein. Results ① We used Vaspin (0, 50, 100 and 200ng/mL) to treat mature adipocytes for 12 hours. Compared with that of the control, PAKT protein expression increased with Vaspin concentration; the difference was significant at concentrations of 100ng/mL and 200ng/mL (P<0.01). ② Glucose consumption was higher in experimental Vaspin group than in model control group (P<0.05); there was no difference in glucose consumption between experimental Vaspin group and control group (P>0.05). ③ Compared with that in control group, protein expressions of IRS-1, PI3K and PAKT in model control group were significantly lower (P<0.01). Wortmannin pretreatment blocked protein expression upregulation of PAKT/AKT, PI3K and IRS-1 by Vaspin. Conclusion Vaspin increases uptake of glucose by insulin-resistant 3T3-L1 adipocytes through insulin signaling pathway and improving insulin resistance