血浆外泌体携带microRNAs在冠脉支架内再狭窄中的作用及分子机制研究

In-stent restenosis (ISR) remains an issue for patients after percutaneous coronary intervention, the mechanism of ISR still need to be clarified. Some studied reported that exosomes, a new communication vector, may regulate the occurrence of ISR by transferring miRNAs to recipient cells. However, there are not direct evidences in the regulation of exosomes-derived miRNAs in ISR. Hence, our aim is to explore the regulating effects and mechanisms of exosomes-derived miRNAs in ISR. The main research contents are as follows: (1) Determining plasma exosomes-derived miRNAs correlated with ISR by miRNAs sequencing technique, bioinformatics analysis and real-time PCR; (2) Analyzing the main cellular sources of differently expressed miRNAs in exosomes; (3) Observing the effects of exosomes-carried miRNAs on the phenotype of smooth muscle cell and on the neointimal hyperplasia of injured artery in mice, and proving the target gene involved in this process. This study will offer new intervention targets and strategy for the prevention and treatment of ISR.

冠脉支架内再狭窄（ISR）是冠心病患者接受经皮冠脉介入治疗后的严重并发症，其发生机制并未完全阐明。研究提示，细胞间新的通讯载体——外泌体，可能会通过转运miRNAs参与ISR的调节，但目前仍缺少外泌体携带miRNAs参与调控ISR的直接证据。因此，本课题研究目的为，探讨血浆外泌体携带miRNAs在冠脉支架内再狭窄中的调控作用及分子机制。本研究拟从冠脉支架内再狭窄主要病变——新生内膜过度增生这一病理改变入手，通过miRNAs高通量测序、生物信息学预测和real-time PCR，筛选、验证与ISR相关的血浆外泌体内miRNAs；分析携带这些miRNAs的外泌体可能的细胞来源；基于ISR相关外泌体主要来源细胞，分别观察其释放的外泌体携带miRNAs对平滑肌细胞表型和小鼠损伤动脉内膜增生的影响，并验证miRNAs作用靶基因。最终为对抗ISR提供新的miRNAs干预靶点及药物研发新策略。

冠状动脉支架内再狭窄（ISR）是冠心病患者接受经皮冠脉介入治疗后的常见并发症，其发生机制并未完全阐明。研究提示，细胞间新的通讯载体——外泌体，可能会通过转运miRNAs参与ISR的调节。本课题研究拟观察血浆外泌体携带miRNAs在冠脉支架内再狭窄中的调控作用及分子机制。主要研究结果如下：1. 与对照患者（无支架内再狭窄）相比，支架内再狭窄患者循环miRNA表达谱发生改变；2. 通过生物信息学预测和靶向信号通路分析显示，miR-16-5p和miR-185-5p参与了支架内再狭窄内皮过度增生的调控；3. 血浆外泌体被受体细胞吞入后，可将生物信息物质miRNAs传递至该细胞内，介导miR-16-5p和miR-185-5p发挥生物学功能。本研究揭示了血浆外泌体携带miRNA对支架内再狭窄的重要生物学调控作用和分子机制。发现血管内皮细胞释放的外泌体，能够被受体细胞摄取，并将生物信息物质miRNAs传递至该细胞内，其中miR-16-5p和miR-185-5p介导了外泌体的促细胞过度增殖作用，进而导致支架内再狭窄发生。