Mechanosensitive M7G epitranscriptome in endothelial health and disease

项目摘要 RNA化学修饰，统称为“表位转录组”，最近出现了 作为一种新的基因表达的分子控制层。大多数表位转录研究都涉及N6- 甲基腺苷(M6A)在人类癌症中的表达。血管内皮细胞mRNA的分子同源性 表位转录组及其在调节血管功能中的潜在作用仍然是一个主要的知识空白。 最近的研究表明，哺乳动物的mRNAs被广泛的化学修饰和mRNAs 修改以依赖于细胞类型和细胞状态的方式发生。N6-甲基腺苷(M6A)，最多 哺乳动物信使核糖核酸中丰富的内部(5‘端外)甲基化与重要的生物学联系在一起 如增殖、发育和干细胞分化等过程。最近只有很少的研究涉及 M6A在心肌细胞重塑和内皮激活中的潜在作用。我们最近 在哺乳动物的信使核糖核酸中发现了一种新的化学修饰--N7-甲基鸟苷(M7G)。 血管内皮细胞m7G基因定位及其在血管病理生理学中的潜在作用 未开发的领域。 血管内皮细胞通过机械转导机制受到血流的动态调节。 血流紊乱引起的血管内皮细胞活化可导致多种血管疾病。动脉硬化 优先发生在血管内皮细胞被局部扰动的血流激活的动脉部位，而 单向流动促进血管内皮细胞健康。目前的动脉粥样硬化治疗主要针对系统性风险。 因素而不是血管系统本身。这突显了识别和识别和 靶向血管内皮细胞新的机械敏感机制。 我们已经产生了非常强大的数据表明，m7G的mRNA在 血流动力学测定血管内皮细胞。单向流(UF)显著增加内皮细胞m7G，但不增加m6A MRNAs。此外，甲基转移酶样7A(METTL7A)是一种新的m7G写入物，调控UF诱导的 血管内皮细胞m7G基因甲基化。这个项目的总体目标是描绘出新的分子 机械敏感型METTL7A调控血管内皮细胞m7G基因及调控血管的机制 在体外和体内发挥作用。此外，我们将设计针对目标的创新的精确纳米医学方法 METTL7A介导的治疗动脉粥样硬化的途径。

Project Summary RNA chemical modifications, collectively referred to as the “epitranscriptome”, have recently emerged as a novel layer of molecular control of gene expression. Most epitranscriptomic studies address N6- methyladenosine (m6A) of mRNA in human cancers. The molecular identity of endothelial mRNA epitranscriptome and its potential role in regulating vascular functions remains a major knowledge gap. Recent studies suggested that mammalian mRNAs are broadly chemically modified and mRNA modifications occur in a cell-type and cell-state dependent manner. N6-methyladenosine (m6A), the most abundant internal (outside of the 5’ cap) methylation in mammalian mRNA, has been linked to critical biological processes such as proliferation, development, and stem cell differentiation. Only few recent studies addressed the potential role of mRNA m6A in cardiomyocyte remodeling and endothelial activation. We recently discovered the presence of a new chemical modification, N7-methylguanosine (m7G) in mammalian mRNA. Systematic m7G mapping in endothelial mRNA and its potential role in vascular pathophysiology is an unexplored territory. Vascular endothelium is dynamically regulated by blood flow via mechano-transduction mechanisms. Endothelial activation by disturbed flow contributes to a wide range of vascular diseases. Atherosclerosis preferentially develops in arterial sites where endothelium is activated by local disturbed flow whereas unidirectional flow promotes endothelial health. Current atherosclerosis therapies mainly target systematic risk factors but not the vasculature per se. This underscores the significance and unique opportunity to identify and target novel mechanosensitive mechanisms in vascular endothelium. We have generated very strong data demonstrating that the mRNA m7G is dynamically regulated in endothelium by hemodynamics. Unidirectional flow (UF) markedly increases m7G but not m6A in endothelial mRNAs. Moreover, Methyltransferase-Like 7A (METTL7A) is a novel m7G writer governing the UF-induced mRNA m7G methylation in endothelium. The overall goal of this project is to delineate the novel molecular mechanisms by which mechano-sensitive METTL7A governs endothelial mRNA m7G and regulates vascular functions in vitro and in vivo. Moreover, we will devise innovative precision nanomedicine approaches targeting METTL7A-mediated pathways to treat atherosclerosis.