小檗碱激活AMPK抑制3T3-L1脂肪细胞分化

摘要

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.%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 adipocytes was observed by oil red 0 staining. Realtime-PCR was used to detect the mRNA ezpiesBions of PPARγ2, CEBPα, 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 10μmol/L berberine, the accumulation of lipid in the cytoplasm of adipocytes was almost inhibited. CEBPa mRNA expression was inhibited by 5μmol/L berberine after 1,3,5, and 7day induction differentiation (P<0.05 or P<0.01) and PPARry2 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 3T3-IA cells were incubated with berberine during differentiation. However, the phoaphorylation levels AMPK and its downstream target gene ACC were significantly increased by berberine. Conclusion Berberine seems to inhibit 3T3-L1 adipocyte differentiation via stimulating AMPK activity.