小檗碱激活AMPK抑制3T3-L1脂肪细胞分化

目的 探讨小檗碱对3T3-L1脂肪分化的作用是否与激活腺苷酸活化蛋白激酶（AMPK）有关.方法 在3T3-L脂肪细胞分化全程加入小檗碱,以油红O染色检测3T3-L1脂肪细胞胞浆中脂肪的堆积,实时定量PCR检测过氧化物酶体增殖物激活受体γ2（PPARγ2）、CCAAT增强子结合蛋白α（CEBPα）和AMPK的mRNA表达,以Western印迹法检测AMPK和乙酰辅酶A羧化酶（ACC）的磷酸化水平.结果 小檗碱剂量依赖性地抑制3T3-L1脂肪细胞分化,10 μmol/L小檗碱几乎完全抑制胞浆中脂肪的堆积.5 μmol/L小檗碱在脂肪细胞诱导分化1、3、5、7d后均显著降低CEBPα mRNA表达（P〈0.05或P〈0.01）,诱导分化3、5、7d时显著降低PPARγ2的mRNA表达（P〈0.05或P〈0.01）.AMPK的mRNA水平在分化过程中未受小檗碱的明显影响,而小檗碱明显增加其蛋白磷酸化水平,其下游靶基因ACC磷酸化水平也明显增加.结论 小檗碱抑制3T3-L1脂肪细胞的分化可能与其激活AMPK有关.

Berberine Activates AMPK and Inhibits 3T3-L1 Adipocyte Differentiation

Objective To investigate whether the effect of berberine （BBR） on 3T3-L1 adipocyte differentiation is related to AMP activated protein （AMPK） activation. Methods The accumulation of lipid in the cytoplasm of differentiated 3T3-L1 adipoeytes was observed by oil red O staining. Realtime-PCR was used to detect the mRNA expressions of PPAR~/2, CEBPot, and AMPK. The phosphorylation levels of AMPK and acetyl CoA carboxylase （ACC） were detected by Western blot. Result Berberine inhibited 3T3- L1 adipocyte differentiation in a dose-dependent manner. At the concentration of 10taanol/L berberine, the accumulation of lipid in the cytoplasm of adipocytes was almost inhibited. CEBPot mRNA expression was inhibited by 51μmol/L berberine after 1,3,5, and 7day induction differentiation （ P 〈 0.05 or P 〈 0.01 ） and PPARγ2 mRNA expression was decreased by berberine after induction differentiation of 3,5, and 7 day （ P 〈 0.05 or P 〈 0.01 ）. There were no changes of AMPK mRNA level after 3＇1＂3-L1 cells were incubated with berberine during differentiation. However, the phosphorylation levels AMPK and its downstream target gene ACC were significantly in- creased by berberine. Conclusion Berberine seems to inhibit 3T3-LI adipocyte differentiation via stimulating AMPK activity.