小檗碱对脂肪细胞分化的影响

目的 探讨小檗碱对脂肪细胞分化的影响和其机制。方法 培养3T3-L1前脂肪细胞。以四甲基偶氮唑盐(MTT)方法检测3T3-L1前脂肪细胞的增殖,以油红O染色检测3T3-L1脂肪细胞分化过程中胞浆脂肪的堆积,同时采用逆转录-聚合酶链反应(RT-PCR)和蛋白质免疫印迹技术检测小檗碱对过氧化脂质体增殖激活受体γ2(PPARγ2)mRNA和蛋白质表达的影响。结果 10μmol/L小檗碱使3T3-L1前脂肪细胞的MTT值增加36%(P<0.001),小檗碱处理的脂肪细胞胞浆中,脂肪的堆积明显少于对照组,仅10％～20％的细胞出现较大脂滴。RT-PCR结果显示,在3T3-L1脂肪细胞分化过程中,小檗碱组脂肪细胞的PPARγ2 mRNR较对照组低48％(P<0.01),蛋白质免疫印迹结果也显示小檗碱抑制PPARγ2蛋白质的表达。结论 小檗碱促进前脂肪细胞的增殖,小檗碱减少脂肪细胞分化过程中脂质的堆积、抑制脂肪细胞的分化,可能与其降低PPARγ2mRNA和蛋白质的表达有关,这提示小檗碱在临床上可能适合于治疗肥胖的2型糖尿病患者。

Effect of berberine on the differentiation of adipocyte

OBJECTIVE: To observe the effect of berberine on the differentiation of 3T3-L1 preadipocytes into adipocytes and to elucidate its mechanism. METHODS: 3T3-L1 preadipocytes were cultured and then divided into 7 groups into whose media were added berberine of the concentrations of 0, 0.1, 1, 10, and 100 micro mol/L, 100 nmol/Linsulin, and 10 micro mol/L berberine + 100 nmol/L insulin. The proliferation of 3T3-L1 preadipocytes was detected by MTT method. The accumulation of lipid in the cytoplasm of differentiated adipocytes was observed by oil red O staining. The peroxisome proliferation activated receptor gamma2 (PPARgamma2) mRNA and protein were detected by RT-PCR and Western blotting respectively. RESULTS: MTT method showed that the absorbance at 570 nm of 3T3-L1 preadipocytes increased by 17% (P < 0.01), 36% (P < 0.001), and 22% (P < 0.05) in the groups of 1, 10, and 100 micro mol/L berberine, by 53% (P < 0.0001)in the group of 100 nmol/L insulin, and by 66% in the group of 10 micro mol/L berberine + 100 nmol/L insulin. There were less and smaller lipid droplets in the 3T3-L1 adipocytes treated with berberine as compared with the untreated control cells and only 10% - 20% of the treated cells displayed big lipid drops. RT-PCR showed that berberine significantly reduced the expression of PPARgamma2 mRNA by 48% (P < 0.01) in the course of 3T3-L1 adipocyte differentiation. Western blotting showed that berberine inhibited the expression of PPARgamma2 protein. CONCLUSION: Berberine promotes the proliferation of 3T3-L1 preadipocytes, decreases the accumulation of lipid drops therein, and inhibits the terminal differentiation of adipocyte, which may be associated with its effect on decreasing the expression of PPARgamma2 mRNA and protein, suggesting that berberine has advantages in the treatment of obesity patients with type 2 diabetes.