自噬在西罗莫司诱导的内皮祖细胞凋亡及阿托伐他汀内皮保护作用中的机制研究

Previous study reveals more delayed re-endothelialization than neointimal coverage after sirolimus-eluting stent implantation(SES). Sirolimus could accelerate the apoptosis of endothelial progenitor cells(EPCs), which had the potential of re-endothelialization, through mTOR/P70S6K pathway. Atorvastatin could activate the autophagy of mesenchymal stem cells and inhibit the apoptosis through the activation of AMPK/mTOR pathway. Thus we hypothesized that autophagy activation through AMPK and its downstream target mTOR may be a novel mechanism of ATV to protect EPCs from apoptosis after SES implantation. By in-vitro cell culture of rat EPC and in-vivo animal model of endothelial denudation of iliac artery, treated with sirolimus with or without hypoxia and serum deprivation（H/SD）, we will detect the autophagy and apoptosis related gene, the expression of anti- or pro-inflammation factors, mTOR C1/C2, eNOS, and the re-endothelialization under the condition of atorvastatin, 3-MA, and compound C, respectively. We hope to reveal the effect of autophagy during the apoptosis of EPC and find a novel way to enhance the delayed endothelialization after SES implantaton, which may decrease the risk of late stent thrombosis. This orginal investigation is novelty designed and with great clinical significance.

本课题组通过前期动物实验的研究结果首次在国际上提出了药物洗脱支架（DES）术后延迟的再内膜化跟再内皮化不同步的重要观点，其机制可能与西罗莫司抑制内皮祖细胞（EPC）功能并促进其凋亡有关。最新研究提示阿托伐他汀可以通过AMPK/mTOR通路促进间充质干细胞自噬从而减少凋亡，而西罗莫司也可通过抑制mTOR发挥作用，因此本研究假设阿托伐他汀能够通过促进EPC的自噬来减少西罗莫司诱导的细胞凋亡，从而改善延迟的再内皮化。拟利用大鼠EPC的细胞实验及兔髂动脉内膜剥脱模型，通过给予西罗莫司联合缺氧无血清模型，模拟冠心病患者中DES对支架再内皮化的影响，分别给予阿托伐他汀、自噬抑制剂3-MA、AMPK抑制剂复合物C，通过检测自噬和凋亡相关基因、炎症介质、mTOR C1/C2及下游eNOS的表达和内膜剥脱处内皮化情况，探讨自噬过程在再内皮化延迟中的作用，进一步明确阿托伐他汀在DES术后内皮保护作用的详细机制