目的探讨ABCG1在高糖促进内皮细胞功能损伤中的作用。方法不同浓度D-葡萄糖(5.6 mmol/L和30 mmol/L)干预血管内皮细胞24~72 h,Real time PCR及Western blotting检测葡萄糖对血管内皮细胞ABCG1 mRNA和蛋白水平的影响,液体闪烁仪分析细胞内胆固醇流出率,并测量葡萄糖干预后内皮细胞NOS活性;使用LXR内源性激活剂22(R)-hydroxycholesterol预先干预内皮细胞2 h,再予不同浓度葡萄糖干预48 h,观察血管内皮细胞ABCG1表达、功能及内皮细胞NOS活性的改变。结果高糖时间依赖性地抑制血管内皮细胞ABCG1mRNA和蛋白水平的表达,同时降低细胞内胆固醇向HDL流出,高糖也降低了内皮细胞eNOS活性。使用22(R)-hydroxycholesterol逆转高糖对ABCG1表达的抑制后,细胞内胆固醇流出率增加,高糖对内皮细胞eNOS活性的抑制也被部分逆转。结论高糖损伤内皮细胞功能的机制可能与高糖降低内皮细胞ABCG1表达相关。
【英文摘要】
Objective To investigate the role of ATP-binding cassette transporter G1(ABCG1) in endothelial dysfunction induced by high glucose.Methods Human aortic endothelial cells(HAECs) were incubated in the presence of 5.6 or 30 mmol/L glucose for 24-72 h with or without a 2-h pretreatment with the LXR agonist 22(R)-hydroxycholesterol.Real-time PCR and Western blotting were used to measure the mRNA and protein expressions of ABCG1;the intracellular cholesterol efflux and endothelial nitric oxide synthase(eNOS) acti...