白细胞介素10对人THP-1源巨噬细胞泡沫化过程中SR-A表达的影响

目的:本研究旨在观察白细胞介素-10(IL-10)对人THP-1源巨噬细胞泡沫化过程中清道夫受体A(SR-A)表达的影响,探讨在动脉粥样硬化形成中IL-10对氧化型低密度脂蛋白(ox-LDL)诱导巨噬细胞泡沫化的干预作用。方法:体外建立泡沫细胞培养体系,将细胞分为5组即THP-1单核细胞组,巨噬细胞组,IL-10刺激巨噬细胞组,ox-LDL刺激巨噬细胞组(泡沫细胞组),ox-LDL和IL-10联合刺激巨噬细胞组。采用RT-PCR和Westernbloting分别检测SR-A的mRNA和蛋白表达变化,脂质油红O化学染色方法检测各组细胞脂质摄取量的情况。结果:当THP-1分化为巨噬细胞时,SR-A开始大量表达;IL-10刺激可显著抑制巨噬细胞组SR-A的表达,其mRNA和蛋白分别下降为未刺激前的0.6倍和0.7倍,泡沫细胞形成率也下降为未刺激前的0.6倍。巨噬细胞经ox-LDL刺激形成泡沫细胞时,SR-A的表达进一步升高,其mRNA和蛋白分别增加为巨噬细胞组的1.5倍和1.4倍,泡沫细胞形成率提高为巨噬细胞组的1.7倍。在此过程中加入IL-10联合刺激,观察到SR-A的表达量有显著降低,其mRNA和蛋白均下降为单用ox-LDL刺激巨噬细胞组的0.4倍,ox-LDL的摄取量也下降为单用ox-LDL刺激巨噬细胞组的0.3倍。结论:IL-10抑制巨噬细胞SR-A表达,IL-10对ox-LDL诱导巨噬细胞SR-A的表达具明显干预作用。IL-10通过抑制SR-A表达可能在抗动脉粥样硬化的发生中发挥重要作用。

Effects of IL-10 on SR-A expression in the oxidized LDL-induced foam cell formation of macrophages derived from human THP-1 Cells

Objective:To study the effects of interleukin-10(IL-10) on expression of scavenger receptor class A(SR-A) in macrophages treated with oxidized low density lipoprotein(ox-LDL) from THP-1 Cells.Method:Human THP-1 cells were cultured with 200 nmol/L PMA for 24 h in order to differentiate the cells to macrophages.The macrophages were incubated with ox-LDL(100 mg/L) for 24 h to form foam cells.We classified these cells to five groups:THP-1 cells,macrophages,macrophages with 20 mg /L IL-10,macrophages with ox-LDL(foam cells),macrophages with ox-LDL and 20 mg/L IL-10 group.RT-PCR and Western blotting analysis were used to detect expression of SR-A,and the formation of foam cells were evaluated by lipid granules formed in the cell by oil redo staining technique.Result:SR-A was highly expressed in the macrophages compared with the human THP-1 Cells.But the expression of SR-A was inhibited when macrophages was stimulated by 20 mg/L IL-10 for 24 h,and the expression of SR-A mRNA and protein was downregulate to 0.6 times and 0.7 times respectively comparcel to the levels before stinulation.The percentage of the foam cell formation was reduced to 0.6 times in the macrophages with IL-10 group compared with the macrophages group.The expression of SR-A was further elevated in the foam cell group compared with the macrophages group,and the expression of SR-A mRNA and protein were elevated to 1.5 times and 1.4 times respectively.Comparced to the levels before stinulation The percentage of the foam cell formation was increased to 1.7 times.When macrophages was stimulated by 100 mg/L ox-LDL and 20 mg/L IL-10 for 24 h,the expression of SR-A was further inhibited,the expression of SR-A on both protein and mRNA levels was depressed 0.4 times,and the percentage of the foam cell formation was fell 0.3 times in the macrophages with ox-LDL and IL-10 group compared with the foam cell group.Conclusion:IL-10 inhibits the SR-A expression in macrophages.IL-10 has pronineatly inhibitory effects on the expression of SR-A in macrophages treated with ox-LDL.The results suggest that IL-10 prevented atherosclerosis by inhibiting the SR-A protein expression.