小白菊内酯改善胰岛素抵抗的分子学机制

Molecular Mechanism of Parthenolide Improving Insulin Resistance Induced by Insulin

目的探讨小白菊内酯(PTL)对胰岛素抵抗(IR)的作用及其分子学机制。方法用不同浓度的胰岛素对Hep G2细胞进行不同时间的诱导,通过葡萄糖氧化酶法测定Hep G2细胞葡萄糖含量,明确建立稳定的Hep G2胰岛素抵抗模型的胰岛素诱导浓度及诱导时间。模型建立后,应用不同浓度PTL分别作用于IR细胞24 h,通过CCK8法评价细胞活性,葡萄糖氧化酶法测定IR模型Hep G2细胞葡萄糖消耗量,明确PTL最佳作用浓度,Q-PCR法检测细胞核因子κB(NF-κB)及IκBαmRNA表达情况,免疫蛋白印迹技术检测蛋白IκBα表达情况。结果 Hep G2细胞产生IR的最佳作用时间是24 h,最佳胰岛素浓度为10μg·m L-1。PTL的最佳作用浓度为20μmol·L-1,应用其干预IR的Hep G2细胞后,与IR的Hep G2细胞相比,NF-κB活性明显降低(P<0.05),IκBα降解被抑制(P<0.05)。结论 PTL可明显抑制IκBα降解,减少NF-κB解离,改善高胰岛素诱导产生的IR。

Objective To investigate the reversal effect and molecular mechanisms of NF-κB inhibitor parthenolide （PTL） on insulin resistance （ IR）. Methods HepG2 cells were treated with insulin at different concentrations and time points, the glucose consumption of HepG2 cells was measured via glucose oxidase method to determine the best concentrations and time for establishing insulin-induced insulin resistance on HepG2 cells. After modeling, different concentrations of PTL were added in cells for 24 h for determining cell activity and glucose-consumption. Q-PCR was used to detect the expression of NF-κB and IκBα mRNA in cells, and western blot was used to detect the expression of protein IκBα. Results The best reaction time and concentration for insulin inducing resistance of HepG2 cells were 24 h and at 10 μg·mL^-1 . The optimum acting dose of PTL was 20 μmol·L^-1 . NF-κB activity was significantly reduced （P〈0. 05）, IκBα degradation was significantly inhibited （P〈0. 05） compared to HepG2 cells with insulin resistance upon intervention on insulin resistance HepG2 cells by PTL. Conclusion PTL can inhibit IκBα degradation and disassociation of it from NF-κB, which in turn improves insulin resistance, providing theo-retical basis for preventing and treating diabetes with PTL.