分泌型miR-186在动脉粥样硬化性心血管疾病中的临床价值和机制研究

Circulating microRNAs (miRNAs) have the potential to be novel biomarkers for cardiovascular disease (CVD). Secreted miRNAs are a class of circulating miRNAs that have physiologic functions and actively secrete from multiply cells, however, whether secreted miRNAs are more valuable than circulating miRNAs remains unknown. Our recent studies found that the secreted miRNAs expression profile of dyslipidemia subjects at different cardiovascular risks were significantly different from that of controls, and following studies revealed that the alteration tendency of secreted miR-186 levels in foam cells induced by oxidized lipoproteins, serum of atherosclerosis mouse model and atherosclerotic plaque was in accordance with human serum. Moreover, the expression levels of secreted miR-186 were significant associated with atherosclerosis progression; nevertheless, the molecular mechanisms were still uncovered. Thus, we hypothesize that specific secreted miRNAs expression profile of dyslipidemia subjects at different cardiovascular risks can be used as novel biomarkers for disease risk prediction, monitoring and prognosis of atherosclerotic CVD patients; miR-186 were originated from atherosclerotic plaque and can be secreted into blood circulating and participate in the development of atherosclerosis, furthermore, miR-186 may use as a potential therapeutic target for atherosclerotic CVD. In order to verify this hypothesis, we will perform a series of experiments in clinical specimens, cell lines and animal models to fully define the clinical value of dyslipidemia related secreted miRNAs in atherosclerotic CVD, and clarify the function of secreted miR-186, the relationship between secreted miR-186 and oxidized lipoproteins as well as the molecular mechanism of this secreted miRNA involving in atherosclerosis. We suspect that results from the present project will provide novel theoretical basis and potential diagnostic and therapeutic approaches for atherosclerotic CVD.

循环miRNA有望成为心血管疾病（CVD）新型标志物；分泌miRNA是细胞主动分泌的一类具备生理功能的循环miRNA，但是否较循环miRNA更具价值尚不清楚。我们新近研究发现，血脂异常危险分层人群分泌miRNA表达谱明显改变；分泌型miR-186在氧化脂蛋白诱导的泡沫细胞、AS模型小鼠血清和AS斑块中变化与人血清一致，且与动脉粥样硬化（AS）进程相关，但作用机制尚不明确。据此，我们提出假说：血脂异常危险分层人群特异分泌miRNA谱是AS性CVD患者发病风险预测、病情监控及预后新指标；miR-186可来源于AS斑块处细胞分泌并进入血循环参与AS进程，是AS性CVD潜在治疗靶点。为验证假说，本项目拟从临床样本、细胞及动物水平全面探讨血脂异常相关分泌miRNA对AS性CVD的临床价值；明确分泌型miR-186与氧化脂蛋白关系、功能及参与AS机制，为AS性CVD的诊断、治疗提供新的途径和理论依据。

分泌miRNA是细胞主动分泌的一类具备生理功能的循环miRNA，但其作为动脉粥样硬化（AS）性心血管疾病（CVD）分子标志物价值及参与AS的作用机制尚不清楚。本项目运用低密度芯片结合qRT-PCR验证，对AS性CVD患者及对照血浆exosome中miRNA表达谱进行测定，发现多种分泌型miRNA在血脂异常高危组、中危组患者中明显升高，部分miRNA在高危患者exosome中变化更为显著，具备作为AS性CVD患者发病风险预测、疗效监控及预后判断指标潜能，其中AS性CVD患者特定变化的血清miR-186可作为PCI手术疗效及预后评估的潜在标志物，高危组ACS患者血清中miR-186非外泌体游离形式（exosome-free）变化尤为显著，其作为PCI疗效及预后评估潜在分子标志物亦更具价值。体外细胞实验显示，ox-LDL引起泡沫细胞内miR-99和miR-139水平增高，且分泌型miR-139可以作为细胞间的交流分子负向调控HUVEC内的靶蛋白IGF-1R，促进HUVEC的凋亡；心肌细胞糖氧剥夺模型证实miR-186主要来源于心肌细胞释放，miR-186可通过抑制ERK1/2蛋白表达参与心肌细胞增殖和凋亡调控。高脂诱导AS模型小鼠实验显示，泡沫细胞来源的exosome可携带miR-139进入AS斑块组织；心肌梗死SD大鼠模型则证实血清miR-186来源于心肌组织破损释放；结合临床研究、体外细胞研究和体内动物研究结果，本项目证实分泌型miRNA具备作为AS性CVD分子标志物潜能，分泌型miR-139和miR-186可分别通过对IGF-1R和ERK1/2表达抑制，对内皮细胞和心肌细胞损伤和凋亡进行调控，共同参与AS性CVD发生发展。本项目累计发表论文18篇，其中SCI论文7篇，多次参加国内外学术会议，可为AS性CVD的诊断、治疗及发病机制研究提供了新的理论依据。