灯盏乙素治疗实验性动脉粥样硬化及其对LOX-1/NF-κB/p38 MAPK信号通路的调控作用研究

Our previous research showed that scutellarin, an active ingredient from Erigeron breviscapus (Vant.) Hand.-Mazz, obviously protected against the injury of vascular endothelial cells, adjusted the levels of serum lipids and regressed the aggravation of aorta in hyperlipidemic rats. Based on our previous research, the atherosclerotic models of apolipoprotein E gene knock-out in mice and high fatty diet combined with balloon injury in rabbits will be duplicated to evaluate the effects of scutellarin on the experimental atherosclerosis and its dose-effect relationships; in vitro, three types of cells are prepared to investigate the protective effects of scutellarin against OX-LDL caused the injury of human umbilical vein endothelial cells, the proliferation and migration of vascular smooth muscle cells and the formation of macrophage-derived foam cells, respectively; the effects of scutellarin on cell cycle of endothelial cells and vascular smooth muscle cells will be detected by flow cytometry; the regulation of scutellarin on LOX-1 / NF-κB / p38 MAPK signal pathways will be aslo determined in aorta atherosclerotic plaques and the above cultured cells through the detection of key targets(LOX-1, ICAM-1, VCAM-1, MCP-1, PKC and TNF-α). The anti-atherosclerotic effects of scutellarin will be explored systematically at these different levels such as model animals, atherosclerotic plaques, cells and molecules, in order to provide more scientific bases and experimental evidences for curing atherosclerosis with scutellarin.

项目组前期研究发现，云南重要的特色药用植物灯盏花的活性成分灯盏乙素能改善血管内皮功能障碍，调节高脂模型大鼠血脂水平，减轻主动脉的病变。在此基础上，本项目拟采用ApoE-/-小鼠和高脂喂养加球囊拉伤家兔两种AS模型，相互印证评价灯盏乙素治疗AS作用并分析其剂量-效应关系；体外培养HUVEC、VSMC和巨噬细胞，探索灯盏乙素对OX-LDL所致内皮细胞损伤、VSMC增殖迁移和巨噬细胞泡沫化的影响；流式细胞仪检测HUVEC和VSMC的细胞周期；以LOX-1、ICAM-1、VCAM-1、MCP-1、PKC、TNF-α等关键分子为靶标深入探索灯盏乙素对主动脉粥样斑块组织和培养的细胞中LOX-1 / NF-κB / p38 MAPK信号通路的调控，以期从整体动物、斑块组织、细胞和分子水平深入系统研究灯盏乙素的抗AS作用。

项目组前期研究发现，云南重要的特色药用植物灯盏花的活性成分灯盏乙素能改善血管内皮功能障碍，调节高脂模型大鼠血脂水平，减轻主动脉的病变。在此基础上，本项目拟采用实验性动脉粥样硬化模型和ox-LDL损伤血管内皮细胞、血管平滑肌细胞和巨噬细胞模型，从整体和细胞水平相互印证评价灯盏乙素的抗动脉粥样硬化作用，并研究灯盏乙素对LOX-1 / NF-κB / p38 MAPK信号通路的中关键靶标的影响，探讨其可能的作用机制。结果表明，在动物实验性动脉粥样硬化模型中，灯盏乙素能明显减轻主动脉病变程度，明显下调主动脉斑块中LOX-1、ICAM-1、VCAM-1、MCP-1、PKC、TNF-α、NF-κB 和 p38 MAPK蛋白及mRNA表达水平；灯盏乙素能明显降低动脉粥样硬化动物血清TC、LDL-C和TG水平，升高HDL-C的水平。灯盏乙素明显拮抗ox-LDL对血管内皮细胞的损伤作用，能使S期细胞比例增加，G1、G2的变异系数减小，sub G1比例减少；灯盏乙素能明显抑制ox-LDL诱导的血管平滑肌细胞的增殖和迁移，抑制血管平滑肌细胞在S期DNA的合成；灯盏乙素能明显抑制巨噬细胞的泡沫化，降低ox-LDL诱导的RAW264.7细胞内总胆固醇及胆固醇酯的含量。在ox-LDL诱导的血管内皮细胞、血管平滑肌细胞和巨噬细胞模型中，灯盏乙素均能明显下调LOX-1、ICAM-1、VCAM-1、MCP-1、PKC、TNF-α、NF-κB 和 p38 MAPK蛋白及mRNA表达水平。研究结果提示，灯盏乙素具有良好的抗动脉粥样硬化作用，其机制与保护血管内皮细胞，抑制血管平滑肌细胞增殖，抑制巨噬细胞泡沫化和调控LOX-1 / NF-κB / p38 MAPK信号通路密切相关。本项目为将灯盏乙素研究成为云南特色植物来源的抗动脉粥样硬化药物提供科学的理论和实验依据。