miR-34a/myc/E2F1信号轴调控树突状细胞成熟和迁移的机制及黄芪多糖的干预研究

Atherosclerosis (AS) is the basic pathology of coronary heart disease. The maturation and migration into atherosclerotic lesions of dendritic cells (DCs) is the key step in promoting the progression of AS. However, little information is known about the mechanism of DCs acquiring maturation and migration under conditions of AS. Our previous studies showed that Astragalus Polysaccharides could suppress the maturation and migration of DCs derived from peripheral blood mononuclear cells in patients with coronary artery disease. Based on our previous studies and the underlying mechanisms of E2F1 suppressing the maturation and migration of DCs, we make a hypothesis that Astragalus Polysaccharides suppresses the maturation and migration of DCs by inhibiting miR-34a/myc/E2F1 signaling axis under conditions of AS. To verify this hypothesis, experimental techniques such as RNA interference, Western-Blot, quantitative PCR and so on, are taken to investigate the roles of miR-34a/myc/E2F1 signaling axis in the maturation and migration of DCs and the mechanisms of Astragalus Polysaccharides suppressing the maturation and migration of DCs in vitro and in vivo. This research intend to further explore the pathogenesis, therapeutic target and effective drug of AS, enrich the anti-atherosclerotic mechanism of astragalus polysaccharide, and thus to discover a new way for prevention and treatment of AS.

动脉粥样硬化（atherosclerosis，AS）是冠心病的病理基础，树突状细胞成熟并迁移至AS病变处是促进AS进展的关键环节。但是，在AS条件下，树突状细胞获得成熟和迁移机制尚未阐明。本课题组研究发现黄芪多糖可抑制冠心病患者外周血单核细胞源性树突状细胞的成熟和迁移。本项目基于前期研究和E2F1抑制树突状细胞成熟和迁移的可能机制提出"在AS条件下黄芪多糖通过作用于miR-34a/myc/E2F1信号轴抑制树突状细胞成熟和迁移假说"。为验证上述假说，本项目拟采用RNA干扰、Western-blot、定量PCR等技术从体内和体外两方面对miR-34a/myc/E2F1信号轴在树突状细胞成熟和迁移中的作用及黄芪多糖的干预机制进行研究。本项目对进一步发掘AS的发病机理、治疗靶点及有效药物，丰富黄芪多糖抗AS的疗效机理，为AS的防治探索一条新的思路与途径。

本课题在国家自然科学基金青年科学基金项目资助下对miR-34a/myc/E2F1 信号轴在树突状细胞（DCs）成熟和迁移中的作用及黄芪多糖（APS）的干预机制进行研究。课题组成功分离培养人单核细胞源性DCs，构建了体内外实验研究模型。本课题组研究发现：miR-34a/myc/E2F1能够促进了DCs成熟和迁移，高剂量APS能够使DCs呈成熟表型、迁移能力增强以及DCs miR-34a表达明显升高，myc和E2F1表达明显降低，DCs培养上清液中炎症因子IL-12和IL-27表达升高。miR-34a过表达载体和高剂量APS联合干预Apoe-/-小鼠后，Apoe-/-小鼠主动脉动脉粥样硬化病变程度减轻，斑块内DCs表达降低，成熟DCs比例增加，外周血IL-12和IL-27表达升高。APS的抗动脉粥样硬化作用可能与激活miR-34a/myc/E2F1信号轴有关。所有工作均按照实验计划进行。目前在此基础上与哈佛医学院麻省总医学神经血管调控研究室开展合作，利用该实验室组织特异性基因（ROCK1、ROCK2、SIRT1等）敲除或过表达小鼠研究平台，对miR-34a/myc/E2F1调控DCs和动脉粥样硬化的作用机制展开深入细致研究。通过本项目的研究，本课题组正在投稿SCI 文章2篇，发表国内期刊3篇，毕业博士研究生1名。