通心络通过调节斑块内胆固醇流动抑制动脉粥样硬化的分子机制研究

Multiple lines of evidence, from genetic, experimental, epidemiological, and clinical studies, have converged on plasma cholesterol, particularly low-density lipoprotein cholesterol (LDL-C), as the principal driver of the initiation and progression of the atherosclerotic plaque. Despite the splendid and remarkable success of statins and other preventive measures introduced toward the end of the 20th century, atherosclerotic cardiovascular disease (ASCVD) still remains the leading cause of death worldwide. Reducing residual risk of ASCVD remains our global challenges. Head of the project first found that tongxinluo enhances stability of vulnerable plaques and the possible mechanisms，which was highly evaluated by the International Academic Circle. Although tongxinluo is not lipid-modifying drugs, it can retard or halt atherosclerosis proved by clinic and experimental studies, however, the mechanism is unknown. On this basis, taking THP1 as the research object, using immunofluorescence cytochemistry，RT-PCR and Western blot analysis to detect the intervention effect of tongxinluo on the form cell formation (cholesterol influx) and reverse cholesterol transport (cholesterol efflux) before and after ox-LDL stimulation, and then, the above hypothesis will be conformed in an animal model of New Zealand rabbits. These results may help to clarify the anti-atherosclerotic mechanisms of tongxinluo, which is benefit to search for a new therapeutic agent for atherosclerosis and provide an effective way to reduce residual risk of ASCVD. It will have wide clinical application and significant social and economic benefits.

遗传，实验，流行病学和临床研究多种证据均证实血浆胆固醇，特别是LDL-C是AS发生发展的主要原因。尽管他汀类取得了引人注目的成功， ASCVD仍然是人类死亡的第一杀手。降低残余风险是全球医师面临的共同挑战。课题负责人曾在国际上首次证明通心络对易损斑块的稳定作用及可能机制，受到国际学术界的高度评价。通心络不是降脂药，但临床和基础研究均证实通心络可减轻或阻止AS发展，但原因不明。本研究拟在此基础上，首先以THP1细胞为研究对象，应用免疫荧光细胞化学、RT-PCR、Western blot等多种分子生物学技术，深入探讨ox-LDL刺激前后应用通心络干预，对泡沫细胞形成（胆固醇内流）和胆固醇逆转运（胆固醇外流）的影响，然后应用新西兰兔腹主动脉AS模型证实以上假说。本研究旨在明确通心络抗AS的机制，为AS防治，进一步降低剩留心血管风险提供有效治疗途径，将具有广阔的临床应用前景和重大的社会经济效益。

课题负责人曾在国际上首次证明通心络对易损斑块的稳定作用及可能机制，受到国际学术界的高度评价。通心络不是降脂药，但临床和基础研究均证实通心络可减轻或阻止AS发展，但原因不明。本研究首先预先使用ox-LDL刺激THP-1细胞6小时使之成为泡沫细胞，再分别加入大、中、小剂量通心络与大剂量辛伐他汀，结果显示通心络可通过上调PPARr 增强LXR-ABCA1/SRBI促进泡沫细胞内胆固醇外流的作用。然后使用大剂量通心络以及大剂量辛伐他汀刺激THP1细胞12小时后加入ox-LDL继续刺激12小时，结果显示，高剂量通心络组以及辛伐他汀组对于DIL-oxLDL的吞噬明显减少，清道夫受体SRA1、 CD36以及PPARr的蛋白水平表达量在药物组明显少于对照组，说明通心络可能通过下调PPARr 抑制SRA1以及CD36的表达，从而减少THP-1细胞对ox-LDL的内吞作用，抑制泡沫细胞的形成。最后，应用新西兰雄性大白兔45只，球囊损伤腹主动脉并继续高脂饲料喂养10周，建立腹主动脉粥样硬化模型，之后普食，并随机分为三组，对照组、通心络组及辛伐他汀组，斑块中LRP表达量在两种药物治疗组中明显降低，与胆固醇外流相关的指标如LXR、ABCA1、SRB1在通心络以及辛伐他汀组的斑块及肝脏内表达均明显高于对照组。因此，通心络可能通过下调斑块内LRP表达抑制胆固醇的内吞，同时促进斑块内胆固醇逆转运途径LXR-ABCA1/SRB1通路，起到逆转AS斑块的作用。以上研究表明对同一种细胞及同一个个体在不同病理背景下，通心络可实现对细胞内或斑块内胆固醇的差异性调控，并阐明其内在机制，相关结果有助于进一步揭示斑块逆转的病理生理机制，为中药防治AS提供有意义的证据。