脂联素通过AMPK调节HepG2细胞中支链氨基酸的代谢

目的:探讨脂联素(APN)对HepG2细胞支链氨基酸(BCAA)分解代谢的影响及其作用机制。方法:将培养的HepG2细胞系随机分为对照组、APN组、APN+腺苷酸活化蛋白激酶(AMPK)抑制剂(Compound C,CpC)组(APN+CpC)组和AMPK激动剂(AICAR)组。用Western blot检测AMPK、P-AMPK、BCKD E1α(BCAA分解代谢过程中的关键酶,磷酸化时为失活状态)及P-BCKD E1α蛋白的表达,用ELISA方法检测培养HepG2细胞上清中BCAA的含量。结果:与对照组相比,APN组和AICAR组均可以显著上调细胞P-AMPK的水平(P0.05,P0.01),显著降低细胞p-BCKD E1α及上清中BCAA的水平(P0.05,P0.01)。与APN组比较,APN+CpC组,其细胞内PAMPK水平显著下降(P0.01),P-BCKD E1α及上清中BCAA的水平明显上升(分别为P0.05及P0.01)。结论:APN可显著促进HepG2细胞BCAA的分解代谢,其作用机制与AMPK磷酸化作用的上调相关。

Adiponectin improves branched-chain amino acid catabolism of HepG2 cells via upregulation of AMPK

AIM ： To investigate the promoter effect of adiponectin （APN） on the branched-chain amino acid （BCAA） catabolism of HepG2 cells and the underlying mechanism. METHODS： HepG2 cells randomly received a control, APN, APN ＋ CpC and AICAR. Expressions of protein p-AMPK, AMPK, p- BCKD E1α and BCKD E1α were analyzed by Western blot and the BCAA level of supernatant from cultured HepG2 was detected by ELISA. RESULTS： Compared with that of vehicle, the supernatant BCAA level from cultured HepG2 significantly decreased （ P 〈 0. 01 ） when APN or AICAR was administered, but the expression of p-AMPK protein from cells increased （P 〈 0. 01 ）. Administration of CpC to HepG2 cells increased the supernatant BCAA level （ P 〈 0.01 ）, but decreased the p-AMPK expression （ P 〈 0. 01 ）. CONCLUSION： Adiponectin notably improves the BCAA catabolism of HepG2 cells through upregulating p-AMPK expression.