花生四烯酸显著预防软脂酸诱导HepG2细胞胰岛素抵抗

Preventing effect of arachidonic acid on HepG2 cell insulin resistance induced by palmitate

目的探讨花生四烯酸(AA)对软脂酸(PA)引起HepG2细胞胰岛素抵抗的预防作用及其可能机制。方法培养HepG2细胞,设立对照组(control组)、软脂酸组(PA组)、软脂酸+花生四烯酸组(PA+AA组)、高胰岛素组(HI组)。PA组、PA+AA组、HI组分别用250μM PA、250μM PA加20μM AA,5×10-7M胰岛素孵育24h。然后葡萄糖氧化酶法测定各组胰岛素刺激后12h点葡萄糖消耗量,蒽酮法测定胰岛素刺激后3h点细胞内糖原含量,Western-blotting技术检测15min点胞内P-Ser473PKB、P-Ser21/9GSK-3α/β水平。结果葡萄糖消耗量PA组与HI组比较差异无统计学意义(P=0.594)。葡萄糖消耗量、细胞内糖原含量、P-Ser473PKB、P-Ser21GSK-3α、P-Ser9GSK-3β水平均显示,PA组与control组比较显著降低(P<0.05),PA+AA组与PA组比较显著升高(P<0.05)。结论AA(20μM)能显著预防PA引起的HepG2细胞胰岛素抵抗,能在PKB、GSK-3水平上显著维持250μM软脂酸孵育HepG2细胞的胰岛素信号传递。

[Objective] To study the effect of arachidonic acid（AA） on preventing HepG2 cell insulin resistance induced.by palmitate（PA） and possible mechanism. [Methods] The model of hepatic insulin resistance was estabhshed induced by PA. HepG2 cells were randomly divided into control group, PA group （250 μM PA）, PA＋AA group （250μM PA plus 20p.M AA） and HI group （5×10^-7TM） and cultured for 24 hours. Then insulin-stimulated glucose consumption was measured using the glucose oxidase method at 12 hours, cell glycogen was measured with anthrone method at 3 hours and protein levels of phosphate-protein kinase B（P-Ser473 PKB） and phosphate-glycogen synthase kinase （P-Ser21/9 GSK-3α/β） at 15 minutes were determined in total cell lysates by Western-blotting. [Results] There was no significant difference in glucose consumption between PA group and HI group （P=0.594）. All levels of glucose consumption, glycogen conten, P-Ser473 PKB, P-Ser21 GSK-3α and P-Set9 GSK-3β in PA group reduced significanfly（P 〈0.05） compared with control group, and increased significantly （P 〈0.05） in PA＋AA group compared with PA group. [Conclusion] AA can prevent HepG2 cell insulin resistance induced by palmitate significantly, keeping insulin-stimulated P-Ser473 PKB and P-Ser21/9 GSK-3α/β levels.