氧化型低密度脂蛋白对正常人外周血单核细胞凝集素样氧化低密度脂蛋白受体-1及尿激酶型纤溶酶原激活剂受体蛋白表达的影响

Effect of Oxidative LDL on Protein Expressions of Lectin Like Oxidized LDL Receptor-1 and Urokinase Type Plasminogen Activator Receptor in Normal Human Peripheral Blood Mononuclear Cells

目的:探讨不同时间点不同浓度氧化型低密度脂蛋白(oxLDL)对正常人外周血单核细胞凝集素样氧化低密度脂蛋白受体-1(LOX-1)、尿激酶型纤溶酶原激活剂受体(uPAR)蛋白的表达情况的影响。方法:选取正常人外周血经Ficoll密度梯度离心法分离人外周血单个核细胞(PBMC),用含20%自体血清的RPMI1640完全培养基培养,收取其帖壁的单核细胞,以免疫印迹杂交法(Western Blot)方法检测不同浓度oxLDL对正常人单核细胞干预24h,72h的uPAR、LOX-1的蛋白表达。结果:oxLDL干预正常人单核细胞24小时后,随着其浓度的增加uPAR及LOX-1蛋白表达上调,在50μg/ml时达峰,而高浓度组(100μg/ml)对两者的蛋白表达起着抑制作用。oxLDL刺激正常人单核细胞72小时后,低浓度(10μg/ml)不能有效地增加uPAR的表达,较高浓度(50μg/ml、100μg/ml)能够较有效地增加uPAR的表达。oxLDL刺激正常人单核细胞72小时后,LOX-1的表达随着浓度的增加而上调,但浓度≥50μg/ml时,其表达有所下降。结论:本研究中oxLDL不同作用时间对uPAR及LOX-1的影响不同,提示了oxLDL致炎症过程的复杂性。

Objective： To investigate the effect of oxidative LDL （oxLDL） on protein expressions of lectin like oxidized low density lipoprotein receptor-1 （LOX-1） and urokinase type plasminogen activator receptor （uPAR） in normal human peripheral blood mononuclear cells （PBMC）. Methods： The normal human PBMC was isolated by Ficoll-paque density gradient centrifugation and cultured with RPMI 1640 medium with 20% antologous serum. Western blot was conducted to detect the effect of oxLDL at different concentrations and time periods on protein expressions of LOX-1 and uPAR in normal human PBMC. Results： For 24-hour oxLDL treatment, the protein expressions of uPAR and LOX-1 were increased with the elevated oxLDL concentrations, oxLDL 50 ~tg/ml was the peak, while the expressions were inhibited by oxLDL 100 μg/ml. With 72- hour oxLDL treatment, the low concentration of oxLDL 10 μg/ml could not increase uPAR protein expression, while oxLDL 50 μg/ml and 100 μg/ml could effectively increase uPAR protein expression; the LOX-1 expression was increased according to the elevated oxLDL concentrations, while the expression decreased at oxLDL ≥ 50 μg/ml. Conclusion： Our work indicated that different concentrations and time periods of oxLDL treatment may affect the protein expressions ofuPAR and LOX-1 at different degrees which suggested that oxLDL-induced inflammatory process was complicated.