氧化低密度脂蛋白对THP-1巨噬细胞吞噬和分泌功能的影响

摘要

目的:探讨氧化低密度脂蛋白(oxidized low density lipoprotein,ox-LDL)对巨噬细胞源性泡沫细胞吞噬功能和炎症相关因子分泌功能的影响.方法:利用佛波酯(phorbol ester,PMA)诱导THP-1细胞分化形成巨噬细胞,之后采用ox-LDL处理48小时后,诱导其形成泡沫细胞.利用中性红吞噬实验,分析泡沫细胞形成前后吞噬功能的变化;通过ELISA法,检测细胞培养上清中肿瘤坏死因子α(tumor necrosis factorα,TNF-α)含量,观察ox-LDL对THP-1巨噬细胞功能的影响.结果:细胞形态学结果表明,我们成功利用ox-LDL诱导THP-1巨噬细胞形成泡沫细胞;进一步发现ox-LDL诱导THP-1巨噬细胞表面的清道夫受体CD36表达升高,并促进细胞吞噬功能增加,进一步促进细胞内胆固醇含量显著升高(P＜0.05);同时,ox-LDL能够刺激巨噬细胞大量分泌TNF-α(P＜0.05).结论:ox-LDL通过增强清道夫受体CD36表达,提高巨噬细胞的吞噬功能,引起大量胆固醇聚集,产生细胞毒性损伤,并促进TNF-α炎性因子的大量分泌.%Objective:To investigate the effect of oxidized low density lipoprotein (ox-LDL) on the phagocytosis and secretory function of the macrophage-derived foam cells.Method:The phorbol ester (PMA) was used to culture and differentiate Human THP-1 cells into macrophages.Afterwards,macrophages were induced 48 hours by the ox-LDL,and turned into foam cells.The change of the phagocytosis function before and after the formation of foam cells was analyzed by the neutral red phagocytosis test,the tumor necrosis factor α (tumor necrosis factor α,TNF-α) level was detected by ELISA,and then the effect of ox-LDL on THP-1 macrophage function was observed.Results:The THP-1 cells were successfully induced into macrophage foam cells evaluating by Oil red O staining,and further ox-LDL significantly enhanced the expression of CD36 on the surface of macrophages.The intracellular cholesterol content increased significantly (P＜0.05) suggesting that ox-LDL could promote the phagocytic function,meanwhile,ox-LDL also could stimulate macrophages to secrete some TNF-α (P＜0.05).Conclusion:By enhancing the expression ofCD36,ox-LDL improve macrophages phagocytosis,leading to a large of cholesterol accumulation,and cytotoxic damage,and promoting inflammatory cytokines secretion such as