高糖通过氧化应激及NF-κB通路抑制血管平滑肌细胞ATP结合盒转运体G1的表达

目的 探讨高糖对人血管平滑肌细胞(VSMCs)表面介导细胞内胆固醇逆向转运的ATP结合盒(ABC)转运体ABCA1和ABCG1表达的影响及可能机制.方法 VSMCs分别与不同浓度的D-葡萄糖(5～30mmol/L)孵育1～7 d,realtime PCR及Western blot方法检测葡萄糖对VSMCs的ABCA1和ABCG1 mRNA和蛋白水平的影响,以及高糖干预的VSMCs经抗氧化剂NAC和NF-κB抑制剂Bayll-7085、TPCK作用后,ABC转运体表达的变化.结果 高糖可时间和浓度依赖性地抑制VSMCs的ABCG1 mRNA和蛋白水平的表达,而对ABCA1的表达影响不明显.抗氧化剂和NF-κB抑制剂几乎可完全逆转高糖对ABCG1 mRNA表达的抑制.结论 高糖可抑制VSMCs表面促进胆固醇流出的重要受体ABCG1表达,其作用机制可能与高糖增加的氧化应激和活化的NF-κB信号通路有关.

High glucose suppresses ABCG1 expression by increasing oxidative stress and inducing nuclear factor-κB activation in vascular smooth muscule cells

OBJECTIVE: To investigate the role of high glucose in the expression of ATP-binding cassette (ABC) transporters A1 (ABCA1) and G1 (ABCG1) in human vascular smooth muscle cells (VSMCs) and its possible mechanisms. METHODS: VSMCs were incubated in the presence of glucose at the concentrations ranging from 5 to 30 mmol/L for 1 to 7 days, and real-time PCR and Western blotting were used to measure the mRNA and protein expressions of ABCA1 and ABCG1. The effects of cells pretreatment with antioxidant NAC (10 mmol/L) and nuclear factor-kappaB (NF-kappaB) inhibitors BAY 11-7085 (10 micromol/L) and TPCK (10 micromol/L) were also tested on ABCA1 and ABCG1 expressions. RESULTS: High glucose suppressed, in a time- and dose-dependent manner, ABCG1 expression in incubated human VSMCs, and this effect was abolished by pretreatment with the antioxidant and nuclear factor-kappaB (NF-kappaB) inhibitors, but ABCA1 expression was not significantly decreased in the presence of high glucose. CONCLUSION: High glucose suppresses ABCG1 expression in human VSMCs possibly due to increased oxidative stress and NF-kappaB activation induced by high glucose.