氧化型低密度脂蛋白对人THP1细胞 Notch1表达及分泌细胞因子的影响

探讨氧化型低密度脂蛋白(oxidized low-density lipoprotein，ox-LDL)刺激人单核细胞株THP1对Notch1表达及分泌细胞因子的影响探讨对动脉粥样硬化(atherosclerosis，AS)发病的可能作用。方法：将人单核细胞株（THP1）经氟波酯 （P M A）刺激转化为巨噬细胞后给予不同浓度ox-LDL刺激，相差显微镜动态观察细胞形态变化，RT-PCR检测不同浓度ox-LDL刺激后细胞表面Notch1 mRNA水平，用Western-blot测定Notch1蛋白表达，用ELISA法测定上清液中血管细胞黏附分子1（vascular cell adhesive molecule1，VCAM-1）和单核细胞趋化分子1（Monocyte chemoattractant protein-1，MCP-1）浓度。结果：ox-LDL诱导48h后巨噬细胞发生树突样细胞形态改变；与对照组相比，OX-LDL能刺激巨噬细胞表面Notch1蛋白和mRNA表达升高(P<0．05)，培养上清液中VCAM-1和MCP-1的表达升高(P<0．05)，在50ng/ml浓度下诱导最佳。结论：ox-LDL能够刺激THP1细胞诱导Notch1表达增加，同时能增加动脉粥样硬化相关细胞因子VCAM-1和MCP-1的分泌，ox—LDL致动脉粥样硬化作用可能部分由Notch1介导。

Effect of oxidized low-density lipoprotein on Notch1 expression and cytokine secretion in THP1 cells

Objective To explore the effect of oxidized low-density lipoprotein (ox-LDL) on Notch 1 expression and cytokine secretion in human acute monocytic leukemia cell line THP1, so as to discuss the role of ox-LDL in atherosclerosis (AS). Methods THP1 cells were stimulated with PMA to induce human macrophages, which were then exposed to ox-LDL of different concentrations. The morphological changes of the cells was observed by phase contrast microscope. The expression of Notch1 mRNA was examined by real-time quantitative PCR (RT-PCR) and protein expression was measured by Western blotting analysis in the cells.The levels of vascular cell adhesive molecule-1(VCAM-1) and monocyte chemoattractant protein-1(MCP-1) in supernatants were determined by ELISA. Results The macrophages differentiated into dendritic like cells 48 h after ox-LDL treatment. Ox-LDL treatment increased Notch1 mRNA and protein expression compared with the control group. Ox-LDL also significantly increased the levels of VCAM-1 and MCP-1 in the supernatant in a dose-dependent manner(P<0.05). The best effect of ox-LDL was seen at the concentration of 50 mg/L. Conclusion Ox-LDL stimulation can increase Notch 1 expression in THP1 cells; meanwhile, it can also promote the secretion of AS-related cytokines. The role of ox-LDL in AS might be partly mediated by Notch1.