YTHDF2介导巨噬细胞中MCOLN1 m6A修饰促进动脉粥样硬化进展

Atherosclerosis is the culprit of critical cardiovascular and cerebrovascular diseases such as coronary heart disease and stroke. Exploring the pathogenesis of atherosclerosis and finding prevention and treatment methods with less side effects and remarkable outcomes are still difficult points in this field. Our study found that m6A levels in the aorta of atherosclerotic mice were significantly down-regulated, and increased expression of reader gene YTHDF2 was the main cause of m6A dysregultion. Knockout of YTHDF2 significantly inhibited plaque progression in mice. Moreover, MeRIP-Seq screened that MCOLN1 was the direct target of YTHDF2. Knockout of YTHDF2 enhances lysosome function by inhibiting MCOLN1 mRNA decay in macrophage. In this study, we will generate ApoE-/- and macrophage MCOLN1-/- mice models, and combine with cell-level experiments. Molecular biological and bioinformatic techniques would be used to further explore the role of YTHDF2 in atherosclerosis by modulating MCOLN1 m6A modification. Besides, assessment of blood YTHDF2 and MCOLN1 expression levels in patients with coronary heart disease will provide an effective clinical approach for early warning and prevention of coronary heart disease. This study will also provide new drug targets for atherosclerotic related diseases.

动脉粥样硬化是导致冠心病、中风等危重心脑血管疾病的元凶，探究动脉粥样硬化的发病机理，寻找副作用小、疗效显著的的防治方法仍是本领域研究的重点问题。本研究发现动脉粥样硬化小鼠主动脉中m6A水平显著下调，读取基因YTHDF2表达增加是诱导m6A变化的主要原因，敲除YTHDF2显著抑制小鼠斑块进展，MeRIP-Seq筛选发现MCOLN1是YTHDF2直接调控靶点，敲除YTHDF2通过抑制MCOLN1 mRNA衰减，增强巨噬细胞溶酶体功能。本项目采用ApoE-/-和巨噬细胞MCOLN1-/-敲除小鼠模型，联合细胞水平实验，应用分子生物学和生物信息学等技术，深入探究YTHDF2介导MCOLN1 m6A修饰在动脉粥样硬化中的作用；同时评估患者血液YTHDF2和MCOLN1表达水平与冠心病进展的相关性，为冠心病的预警和预防提供有效的临床应用手段，也为动脉粥样硬化型心脑血管病的治疗提供新的药物研发靶点。

冠心病主要归因于冠状动脉粥样硬化性病变，针对早期动脉粥样硬化的治疗可以提早预防冠心病等致死性心血管疾病的发生。N 6-腺苷酸甲基化（N 6-methyladenosine，m6A）是真核细胞中最常见且最丰富的信使RNA（Message RNA，mRNA）修饰形式，参与调控多种疾病的发生发展。YT521-B同源域家族 2（YT521-B homology domain family 2，YTHDF2）作为第一个被发现的m6A阅读蛋白，通过直接招募CCR4-NOT脱腺苷酸化酶复合体，促进m6A修饰的 mRNA发生降解。目前已有研究发现YTHDF2参与调控心血管疾病，但YTHDF2能否在动脉粥样硬化进展中发挥关键调控作用尚不清楚。巨噬细胞在动脉粥样硬化斑块形成，发展，甚至破裂的过程中发挥决定性作用，也是决定恶性心血管事件发生的根本因素。大量证据表明，溶酶体在调节巨噬细胞功能方面起到关键作用，动脉粥样硬化进展过程中巨噬细胞溶酶体功能异常，但引起溶酶体功能异常的“关键基因”或“始动因子”仍有待发现。本研究旨在探究YTHDF2介导的m6A修饰在动脉粥样硬化进展中的作用，阐明YTHDF2靶向调控溶酶体特异性瞬时受体电位通道粘脂蛋白1（Transient receptor potential channel mucolipin 1，TRPML1）对巨噬细胞溶酶体稳态的调控作用及机制，为动脉粥样硬化的防治提供新的药物靶点。