【摘要】 目的观察依泽替米贝对血管平滑肌源性荷脂细胞三磷酸腺苷结合盒转运体A1和肝X受体α表达的影响,探讨依泽替米贝促进血管平滑肌源性荷脂细胞胆固醇流出的作用机制。方法采用20mg/L胆固醇、β环糊精混合物处理大鼠主动脉平滑肌细胞建立荷脂细胞模型,用不同浓度的依泽替米贝(3、10μmol/L和30μmol/L)处理荷脂细胞24h,选择30μmol/L的依泽替米贝处理荷脂细胞不同的时间(0、6、12、24h和48h)。通过逆转录聚合酶链反应检测三磷酸腺苷结合盒转运体A1 mRNA变化和免疫印迹法检测肝X受体α蛋白的表达。结果(1)三种浓度的依泽替米贝处理荷脂细胞后,逆转录聚合酶链反应显示随着依泽替米贝浓度增加,血管平滑肌源性荷脂细胞三磷酸腺苷结合盒转运体A1的mRNA表达明显上调,30μmol/L依泽替米贝处理24h组相比模型组上调3.4倍左右;当选用30μmol/L依泽替米贝处理荷脂细胞不同的时间(0、6、12、24h和48h)后,三磷酸腺苷结合盒转运体A1的mRNA水平在0～24h之间随时间增加而增加并于24h达到峰值。(2)三种浓度的依泽替米贝处理荷脂细胞后,免疫印迹结果显示随着浓度增加血管平滑肌源性荷脂细胞肝X受体α蛋白的表达逐步增加,其中30μmol/L依泽替米贝组作用最强,较模型组增加2倍多。30μmol/L依泽替米贝分别处理荷脂细胞不同时间(0、6、12、24h和48h)后,肝X受体α蛋白表达随时间增加而增加,24h组作用最佳。结论依泽替米贝能明显上调平滑肌源性荷脂细胞ATP结合盒转运体A1和肝X受体α表达。更多还原

【Abstract】 Aim To investigate the mechanism of ezetimibe-induced cholesterol efflux by observing the effect of ezetimibe on ATP binding cassettet transporter A1 and Liver X Receptor α in lipid-loaded cells derived from vascular smooth muscle cell(VSMC). Methods Lipid-loaded cell model was established with the mix of 20 mg/L Chol∶MβCD treating VSMC. Lipid-loaded cells were treated with different concentration of ezetimibe(3,10,30 μmol/L)for 24 hours respectively,and 30 μmol/L ezetimibe was selected for lipid-loaded cell treatment of different time respectively (0,6,12,24,48 h). ATP binding cassettet transporter-A1 mRNA was detected by reverse transcription PCR(RT-PCR) and the protein expression of Liver X Receptor α was examined by Western-blotting. Results (1) With different concentration of ezetimibe treated lipid-loaded cells,the mRNA expression of ATP binding cassettet transporter-A1 increased with concentration. Compared with the model group,the 30 μmol/L ezetimibe-treated group (24 h ) had a 3.4 folds rising. Treated with 30 μmol/L ezetimibe for different time(0,6,12,24,48 h),the mRNA expression of ATP binding cassettet transporter-A1 had a time dependant trend reaching plateau at 24 h and the best concentration was 30 μmol/L. (2) With different concentration of ezetimibe treated lipid-loaded cells,the protein expression of Liver X Receptor α increased with rising concentration. Compared with the model group,the 30 μmol/L ezetimibe-treated group(24 h) had an increase of more than 2 folds. Treated with 30 μmol/L ezetimibe for different time(0,6,12,24,48 h),the protein expression of Liver X Receptorα had a time dependant trend with 24 h reaching plateau and the best time was 24h. Conclusion Ezetimibe promotes cellular cholesterol efflux in lipid-loaded cells derived from VSMC by up-regulating Liver X Receptorα and ATP binding cassettet transporter-A1 expression.更多还原