基于mTOR通路介导的自噬探讨丹蒌片抗动脉粥样硬化的机制研究

Atherosclerosis is characterized by impaired arterial wall and lipid deposition. Recent studies have shown that vascular adventitia actively participates in atherosclerosis progression and the lesion occurs before the intima and tunica media. Autophagy is closely related to atherosclerosis, and the mTOR pathway is the key link in autophagy. Our previous studies have shown that Danlou Tablets has the effect of modulating blood lipid, inflammation level and inhibiting hyperplasia in the intima, but whether it plays an anti-atherosclerotic role by regulating autophagy has not been reported yet. We hypothesized that the Danlou Tablets may be mediated by mTOR pathway, improve the AFs' proliferation, apoptosis, adhesion , and reduce tissue inflammatory damage, improve vascular remodeling. This project intends to use the ex vivo and in vivo experiments, through the mTOR autophagy pathway as the starting point, revealed autophagy in the development of atherosclerosis using transmission electron microscopy, to lighten the role of Danlou Tablest, that how it could though regulating the autophagy pathway to treat atherosclerosis and the mechanism for the treatment and to provide the basis for traditional Chinese medicine of treating atherosclerosis.

动脉损伤反应与脂质代谢异常是动脉粥样硬化的病理基础。近年研究发现血管外膜主动参与动脉粥样硬化进程且病变出现在内膜和中膜之前。自噬与动脉粥样硬化关系密切，mTOR通路是自噬发生的关键环节。我们前期动物实验显示丹蒌片具有改善血脂、炎症水平、抗动脉粥样硬化的作用，但其分子机制尚不清楚。我们推测丹蒌片可能通过mTOR通路介导的自噬，影响血管外膜成纤维细胞增殖、凋亡、粘附等功能，减轻组织炎症损伤，改善血管重构，起到抗动脉粥样硬化的作用。本项目拟通过离体和在体实验，以mTOR通路为切入点，采用透射电镜等技术观察自噬在动脉粥样硬化形成中的作用，揭示丹蒌片通过血管外膜抗动脉粥样硬化的调控效应与机制，为中医从“痰瘀”理论治疗动脉粥样硬化提供依据。

动脉粥样硬化（Atherosclerosis，AS）是危害人类健康的常见疾病，临床上常导致严重心脑血管病及外周血管疾病。近年研究发现血管外膜主动参与动脉粥样硬化进程且病变出现在内膜和中膜之前。自噬与动脉粥样硬化关系密切，mTOR通路是自噬发生的关键环节。我们前期动物实验显示丹蒌片具有抗动脉粥样硬化的作用，调控PI3K、Akt蛋白表达。本研究以mTOR通路为切入点，在体实验方面采用apoE基因敲除小鼠构建AS动物模型，观察到丹蒌片具有减轻AS病理损伤、脂质沉积、血管纤维化，降低血脂、降低炎症因子表达的作用，减少粘附分子ICAM-1和VCAM-1表达，同时使AS小鼠主动脉外膜mTOR通路的关键分子p-AKT、p-mTOR、p-S6表达下降，提示丹蒌片可能通过mTOR通路激活血管外膜自噬。体外研究表明丹蒌片降低ox-LDL诱导下血管外膜成纤维细胞p-mTOR等蛋白表达，增强mTOR通路中促自噬体形成的Beclin-1、LC3Ⅱ/ LC3Ⅰ蛋白表达，使自噬溶酶体增加。进一步应用自噬抑制剂证明丹蒌片通过mTOR通路激活血管外膜成纤维细胞细胞自噬，抑制血管外膜成纤维细胞增殖、迁移能力。综上所述，丹蒌片可能通过抑制mTOR通路激活自噬，抑制血管外膜成纤维细胞增殖、迁移功能，减轻组织炎症损伤，改善血管重构，起到抗 AS 的作用，自噬可能是“痰浊血瘀”清除机制的微观体现。本研究揭示了丹蒌片对动脉粥样硬化斑块的影响以及干预靶点，为阐释丹蒌片抗AS的痰瘀清除理论和药效调控提供物质基础和实验依据。