连翘苷对小鼠主动脉斑块形成和巨噬细胞炎症信号转导的干预作用研究

According to the theory of traditional Chinese medicine, Forsythia suspensa, which has been widely used as an antipyretic and antidotal herb, can prevent the development of atherosclerosis. Phillyrin is one of the main bioactive components from forsythia suspensa. It has previously been reported that phillyrin possesses some important biological activities, such as hypolipidemic, antioxidant and anti-inflammatory, etc. Atherosclerosis is a chronic inflammatory disease. Since the formation of atherosclerotic plaques is closely related to inflammation, lipid accumulation and peroxidation, phillyrin may attenuate atherosclerotic plaques development. Macrophages are known to be critical players in atherosclerotic inflammation. TLR4 is a critical mediator of signal transductions in macrophages. Both MAPK and NF-κB are key inflammatory signaling pathways down-stream of TLR4. According to the recent reported reference, phillyrin attenuates LPS-induced pulmonary inflammation via suppression of MAPK and NF-κB activation in acute lung injury mice, however, the role of phillyrin in macrophage-mediated MAPK and NF-κB activation is unknown. To address this issue, we will analyse the effects of phillyrin on atherosclerotic plaque formation in apoE gene-knockout mice. Moreover, to study how phillyrin affects inflammatory responses in macrophages, we will measure the expression of TLR4 receptor, MAPK and NF-κB signal transductions and the expression of some proinflammatory chemokines and cytokines in bone marrow-derived macrophages induced by LPS. In this study, we primarily concern a novel therapeutic role of phillyrin, which may offer a new perspective for preventing atherosclerosis.

本项目以载脂蛋白E基因敲除小鼠为动脉粥样硬化（AS）模型，研究连翘苷对主动脉AS斑块形成的影响和对巨噬细胞炎症信号转导的干预作用。研究依据为：一、传统中医理论下连翘作为清热解毒类中药具有抑制AS发展的趋势，现代医学研究显示连翘苷具有降血脂、抗氧化和抗炎等作用，而根据AS斑块形成的机理，连翘苷很有可能会抑制AS斑块的形成，但目前国内外尚无连翘苷干预AS斑块形成的研究报道；二、在分子机制上，已有研究表明连翘苷可减轻肺组织MAPK和NF-κB途径的活化程度，而通过减轻巨噬细胞MAPK和NF-κB途径的活化程度可抑制AS斑块的形成，连翘苷这一可能抑制AS的机制研究国内外尚无报道。本项目旨在揭示连翘苷干预AS的疗效和可能的作用机制，为深入挖掘和研究开发治疗AS的可能新药提供新的思路。

连翘作为清热解毒类中药，常规用于治疗流感、温热和疮疡等病症。连翘苷是连翘的主要化学成分之一, 近年来被发现具有降血脂、抗氧化和抗炎等药理作用。由于动脉粥样硬化(AS)斑块的形成与脂质堆积、脂质过氧化和炎症等病变密切相关，所以连翘苷很可能会对AS斑块的形成产生影响。本项目以载脂蛋白E基因敲除小鼠建立AS模型，一方面研究连翘苷对主动脉AS斑块面积的影响，另一方面研究连翘苷对AS小鼠骨髓来源巨噬细胞TLR4表达及其下游NF-κB信号通路信号转导，以及对胆固醇流出相关基因的影响，旨在揭示连翘苷干预AS的疗效和可能的作用机制，为深入挖掘和研究开发治疗AS的可能新药提供新的思路。本项目研究结果发现，连翘苷对AS小鼠主动脉粥样斑块面积具有抑制作用，抑制率约为30%；连翘苷可以降低AS小鼠骨髓来源巨噬细胞中TLR4和NF-κB蛋白的表达、降低细胞培养上清液中IL-6和MCP-1蛋白的表达、增加与胆固醇流出相关的PPAR-r、ABCA1、ABCG1和SR-B1基因的表达。连翘苷干预AS的作用机制可能与减轻巨噬细胞炎性通路的活化、促进巨噬细胞胆固醇流出的途径有关，后续还有进一步研究和开发应用的价值。