小檗碱对THP-1巨噬细胞源性泡沫细胞胆固醇流出的影响

Effects of berberine on cholesterol efflux in THP-1 macrophage derived foam cells

目的观察不同浓度小檗碱对THP-1巨噬细胞源性泡沫细胞胆固醇流出的影响,并探讨其可能的作用机制。方法佛波酯(PMA)刺激THP-1细胞分化为巨噬细胞后经乙酰化低密度脂蛋白(AcLDL)诱导泡沫化,建立THP-1巨噬细胞源性泡沫细胞模型。根据小檗碱干预与否及干预浓度将泡沫细胞分为空白对照组和小檗碱(5～20μmol/L)干预组。细胞经分组处理24h后,流式细胞仪检测AcLDL聚集量;酶法检测胆固醇和乙酰甘油含量;闪烁计数法检测各组胆固醇流出率,同时分析过氧化物酶体增殖物激活受体γ(PPARγ)抑制剂GW9662预处理对胆固醇流出率的影响(以吡格列酮作为阳性对照);RT-PCR检测肝X受体α(LXRα)和三磷酸腺苷结合盒转运体A1(ABCA1)mRNA表达。结果与空白对照组比较,不同浓度小檗碱干预组泡沫细胞内AcLDL聚集量及胆固醇和乙酰甘油含量均显著减少(P<0.01),而胆固醇流出率上升(P<0.01),并呈现一定的量效关系。GW9662预处理后,不同浓度小檗碱干预组泡沫细胞的胆固醇流出率与对照组比较,差异均无统计学意义(P>0.05)。不同浓度小檗碱干预组泡沫细胞LXRα和ABCA1mRNA表达均高于空白对照组。结论小檗碱可增加THP-1巨噬细胞源性泡沫细胞胆固醇的流出量,其作用机制可能与激活PPARγ途径,增加LXRα和ABCA1mRNA表达有关。

Objective To investigate the effects of berberine on cholesterol efflux in THP-1 macrophage derived foam cells, and explore the possible mechanism. Methods HP-1 cells were induced into macrophages by phorbol myristate acetate （PMA）, and were treated with acetylated low-density lipoprotein （Ac-LDL） to establish the THP-1 macrophage derived foam cell models. Foam cells were divided into blank control group and berberine （5 to 20 μmol/L） treatment groups according to the way of treatment and berberine concentrations. After treatment for 24 h, flow cytometry was employed to detect AcLDL aggregation, enzymic method was adopted to detect contents of cholesterol and triglyceride, scintillation counting technique was used to detect cholesterol efflux, and effects of peroxisome proliferator-activated receptor-γ （PPARγ） antagonist GW9662 pretreatment on cholesterol efflux （pioglitazone as positive control） were analysed. Besides, RT-PCR was applied to detect expression of liver X receptor α （LXRα） and ATP binding cassette transporter A1 （ABCA1） mRNA. ResultsCompared with blank control group, AcLDL aggregation and contents of cholesterol and triglyceride of foam cells in various berberine treatment groups decreased significantly （P〈0.01）, while cholesterol efflux increased （P〈0.01） in a dose-dependent manner. After GW9662 pretreatment, there was no significant difference in cholesterol efflux between various berberine treatment groups and control group （P〉0.05）. Furthermore, expression of LXRα and ABCA1 mRNA of foam cells in various berberine treatment groups was higher than that in blank control group. Conclusion Berberine may increase cholesterol efflux in THP-1 macrophage derived foam cells, the mechanism of which may be associated with activation of PPARγ pathway and increase of expression of LXRα and ABCA1 mRNA.