免疫干预转变巨噬细胞脂质处理模式及其生存命运抑制动脉粥样硬化研究

The general process of pathogenesis of atherosclerosis involved macrophage is initiated by the phagocytosis of oxidized lipid via pattern-recognition receptors, which can induce and maintain the inflammatory response and, ultimately, the macrophage will die through apoptotic or necrotic mechanism after lipid overloaded. One strategy to prevent the pathogenesis of atherosclerosis is to transform the macrophage phagocytosis pattern to the oxidized lipid and promote to efflux the cholesterol from atherosclerosis plaque. We hypothesize that using the specific antibody against oxidized lipid will induce the macrophage in dealing with lipid from "phagocytosis via pattern recognition receptors-inducing inflammation" to "phagocytosis via specific antibody-promoting cholesterol efflux". This pathway of lipid-processing pattern will inhibit inflammation reaction, promote cholesterol efflux, avoid excessive lipid load, and improve macrophage survival fate, which all contribute to the pathogenesis of atherosclerosis. The main parts in the present project include: the intervention with anti-MDA-apoB-PF antibody in apoE-/- mouse model, the observation of cholesterol phagocytosis and metabolic changes in animal tissue; the observation of the inhibition of NF-κB regulated inflammation reaction; the observation of the expression PPARα and cholesterol efflux related molecules; the observation of the fate of macrophage overloaded lipid, including autophagy, apoptosis, and necrosis, and at last we will observe the difference of atherosclerosis lesions in different treatment groups. Meanwhile, we will investigate the mechanisms in macrophage cells in vitro. The main purpose is to elucidate the role and mechanism of antibody against MDA-apoB-PF which mediates the transforming of lipd-processing pathway and improving the survival fate of macrophage in the prevention and treatment of atherosclerosis.

巨噬细胞通过模式识别受体吞噬氧化脂质，启动维持炎症反应并最终凋亡坏死是动脉粥样硬化发展的基本脉络。如能利用特异性抗体分子作为介导，免疫干预转变这一通路，使巨噬细胞对脂质的"模式识别受体非特异性吞噬-诱导炎症反应"处理模式转变为"特异性受体吞噬-胆固醇外流转运"模式，可抑制炎症反应形成，促进斑块内胆固醇外流，避免脂质过度负荷，减轻巨噬细胞死亡命运，实现动脉粥样硬化的抑制。具体内容包括：制备负载MDA-apoB-PF抗体的apoE敲除鼠模型，观察血管组织巨噬细胞氧化脂质吞噬和代谢途径的改变，NF-κB炎症系统的抑制，PPARα及胆固醇外流分子表达的增强；观察负脂巨噬细胞自噬、凋亡的命运差异和动脉粥样硬化病变的形成情况。同时，从离体细胞水平探讨上述作用及其机制，并用多层次药物干预作为验证。最终明确MDA-apoB-PF抗体介导巨噬细胞脂质处理模式和巨噬细胞生存命运的转变对动脉粥样硬化的防治作用。

项目背景：巨噬细胞通过模式识别受体吞噬氧化脂质，启动维持炎症反应并最终凋亡坏死是动脉粥样硬化发展的基本脉络。如能利用特异性抗体分子作为介导，免疫干预转变这一通路，使巨噬细胞对脂质的“模式识别受体非特异性吞噬-诱导炎症反应”处理模式转变为“特异性受体吞噬-胆固醇外流转运”模式，可抑制炎症反应形成，促进斑块内胆固醇外流，避免脂质过度负荷，减轻巨噬细胞死亡命运，实现动脉粥样硬化的抑制。主要研究内容：制备负载MDA-ApoB-PF 抗体的ApoE 敲除鼠型，观察血管组织巨噬细胞氧化脂质吞噬和代谢途径的改变，NF-κB炎症系统的抑制，PPARα及胆固醇外流分子表达的增强；观察负脂巨噬细胞自噬、凋亡的命运差异和动脉粥样硬化病变的形成情况。同时，从离体细胞水平探讨上述作用及其机制。最终明确MDA-apoB-PF抗体介导巨噬细胞脂质处理模式和巨噬细胞生存命运的转变对动脉粥样硬化的防治作用。重要结果及关键数据：我们用有效免疫片段P210及其特异性抗体P210Ab进行相关体内及体外研究，发现P210可以减少巨噬细胞经清道夫及Toll样受体通路清除循环中Ox-LDL进而减少血管下炎症反应及泡沫细胞形成，最终减轻动脉粥样硬化病变，此外我们发现P210可以减轻血管内皮细胞LOX-1受体途径介导的内皮凋亡从而保持血管内皮屏障的完整性。科学意义：血管内皮下持续炎症反应并泡沫细胞形成以及内皮屏障完整性破坏在动脉粥样硬化性病变中起着关键作用，通过免疫干预途径减少Ox-LDL诱导的内皮下炎症反应及血管内皮屏障的破坏，最终使动脉粥样硬化病变从启动到发展环节得以抑制。