OxLDL诱导人血管内皮细胞及平滑肌细胞DNA加合物生成

OXIDIZED LOW DENSITY LIPOPROTEIN INDUCES THE FORMATION OF DNA ADDUCTS IN HUMAN VASCULAR ENDOTHELIAL AND SMOOTH MUSCLE CELLS

目的探讨oxLDL参与动脉粥样硬化发生的可能机制。方法培养人血管内皮细胞及平滑肌细胞,以50μg/L oxLDL刺激24、48h后,收获细胞用于后续实验：①免疫组化染色检测DNA加合物εdA水平;②免疫组化方法检测细胞内4-HNE修饰蛋白;③western blot法检测细胞内4-HNE修饰蛋白水平。结果oxLDL刺激EC及SMC中DNA加合物εdA水平及4-HNE修饰蛋白水平均较未刺激细胞组明显升高。结果 oxLDL诱导的氧化应激、脂质过氧化反应及其继发的DNA损伤可能为oxLDL参与动脉粥样硬化发生的重要机制。

Objective To investigate the pathogenesis of oxidized LDL（oxLDL） in the progression of atherosclerosis.Methods To correlate oxLDL and macromolecular damage,we measured levels of LPO-derived miscoding etheno-DNA adducts and LPO-modified proteins in cultured human vascular endothelial and smooth muscle cells after incubation with oxLDL for up to 48h.A semi-quantative analysis method for 1,N6-etheno-deoxyadenosine（εdA） by immunohistochemistry was applied.Results After oxLDL stimulation,a marked and significant increase of εdA-stained nuclei was found in both endothelial and smooth muscle cells.Similarly,4-hydroxy-2-nonenal– modified proteins,as analyzed by immunohistochemistry and Western blot,showed a 3-5 fold increase.Conclusion LPO-derived etheno-DNA adducts and LPO-modified proteins are strongly induced by oxLDL in human vascular endothelial and smooth muscle cells.This macromolecular damage may contribute to the dysfunction of arterial endothelium and the onset of atherosclerosis.