氧化低密度脂蛋白功能性调节人内皮细胞的生长调节致癌基因α

摘要

Objective To explore the effect of oxLDL on CXC chemokine growthregulated oncogene α (GROα) expression in human endothelial cells and the possible functional significrnance of the effect Methods LDL was isolated by sequential ultracentrifugation and oxidized to oxLDL Reverrnse transcriptionpolymerase chain reaction with GAPDH as internal standard was applied and CXC chemokine GROα mRNA in endothelial ECV304 cells was examinedrnELISA was used to determine GROα protein expression on ECV304 cell surface and in the medium With static cell adhesion assays, the physiological significarnnce of elevated GROα expression was tested Results OxLDL, not LDL, treatment of ECV304 cells significantly induced the expression ornf GROα mRNA that was not detectable in untreated cells Induction of expressiornn was first evident at 1h, became maximal at 2h, and was substantially decrernased by 4h In a concentration and timedependent manner, oxLDL, and not LrnDL, induced a significant upregulation of GROα surface expression in ECV304 celrnls that was at a barely detectable level in unstimulated ECV304 cells GROα protein in the medium did not change significantly Exposure of ECV304 cells to rn40μg protein /ml oxLDL for 24h resulted in a marked increase in the number of U937 cells bound to ECV304 cells and antibodies to GROα inhibited adhesion Conclusion OxLDL functionally upregulated GROα expression in endothelial cells%目的探讨oxLDL对人内皮细胞的CXC亚家族趋化因子GROα的调节作用及生理意义。方法超高速离心得LDL，氧化后得oxLDL。逆转录PCR分析人内皮细胞系ECV304细胞GROα mRNA。APDH被用作PCR中正常改变的对照物。酶联免疫检测仪测定ECV304细胞表面连接及分泌到溶液中的GROα蛋白。静态细胞粘附试验测定ECV304细胞表面连接的GROα蛋白的生理意义。结果正常ECV304细胞不表达GROα mRNA;OxLDL显著调节其表达，证据首先在处理后1h，最大在2h，在4h时下降。相比较，LDL对其mRNA表达没有影响。正常ECV304细胞低水平表达细胞表面的GROα蛋白。OxLDL呈浓度依赖性、时间依赖性地上调其表面的GROα蛋白。相比较，LDL对其表面表达的GROα蛋白无调节作用。OxLDL对ECV304细胞分泌到细胞溶液中GROα蛋白很少有影响。40μg/ml oxLDL处理ECV304细胞24h造成显著的人单核细胞系U937细胞粘附到ECV304细胞数目的增加。用GROα抗体预处理oxLDL刺激的ECV304细胞显著减低了U937细胞粘附到ECV304细胞的U937细胞数目（大约2/3）。结论 oxLDL可能功能性上调内皮细胞GROα的表达。