小檗碱对3T3-L1脂肪细胞内脂素表达的影响

Effect of berberine on visfatin expression in 3T3-L1 adipocytes

目的观察小檗碱对3T3-L1脂肪细胞内脂素(visfatin)表达的影响和探讨小檗碱改善胰岛素抵抗的机制。方法采用RT-PCR法检测不同浓度小檗碱和不同作用时间后,3T3-L1脂肪细胞内脂素mRNA的表达,并以Western印迹方法检测其蛋白水平的表达。结果0～10μmol/L小檗碱剂量依赖性地增加内脂素mRNA的表达,其中10μmol/L时最明显,是空白对照组的4.96倍,其后随着小檗碱浓度的进一步增加,内脂素mRNA的表达反而降低;10μmol/L的小檗碱作用3 h后内脂素mRNA的表达开始明显增强,至作用12 h时表达增强最明显,是基础组的4.57倍,随着作用时间的延长内脂素mRNA的表达虽然有所下降,但到48 h时内脂素mRNA的表达仍比空白对照组明显增高;5、10、20μmol/L的小檗碱均可使内脂素蛋白的表达增加1.13、2.46、2.34倍,与空白对照组相比差异有统计学意义(P<0.05或P<0.01)。结论在一定浓度范围内小檗碱可剂量和时间依赖性地促进离体脂肪细胞内脂素mRNA及蛋白表达。小檗碱对内脂素表达的调节作用可能是其改善机体胰岛素抵抗、降低血糖的机制之一。

Objective To observe the effect of berberine on visfatin expression in 3T3-L1 adipocytes, and to explore the mechanism underlying berberine improving insulin resistance. Methods Visfatin mRNA and protein expressions were assayed by RT-PCR and Western blot after incubation of berberine at different concentrations and durations with 3T3-L1 adipocytes. Results In 3T3-L1 adipocytes, visfatin mRNA expression was increased at 0- 10 μmol/L berberine with the maximum effect at 10 μmol/L, being 4.96 folds of control group. While as the berberine concentrations were further increased above 10 μmol/L, the visfatin mRNA level decreased. After incubation with berberine for 3 h, the visfatin mRNA level began to increase, and reached the peak when incubation for 12 h （4.57 fold of basal group）. Then the mRNA level decreased, though it was still higher than that in control group after 48h intervention. 5, 10, 20 μmol/L berberine could increase visfatin protein expression by 1.13, 2.46, 2.34 folds respectively as compared with control group （ P 〈 0.05 or P 〈 0.01 ）. Conclusion Berberine at certain concentrations show dose- and time-dependent enhancement of visfatin gene and protein expressions in cultured 3T3-L1 adipocytes, which seems to be one of the mechanisms underlying the action of berberine on decreasing blood glucose and improving insulin resistance.