Epitranscriptomic Mapping of Novel N6-Adenosine-based RNA Methylation in MDD Brain

严重抑郁障碍(MDD)目前仍然是导致全球残疾的主要原因之一。尽管 随着治疗选择的增加，MDD患者的缓解率非常低。因此，迫切需要确定 在MDD中沉淀的生物底物，以开发有效的治疗方法。众所周知，MDD 涉及对外部刺激的短期和长期适应不良过程，损害个人 适当地与环境互动。到目前为止，还没有一个连贯的假设可以完全解释这一点 现象。越来越多的证据表明，基因环境对转录调控的微调 相互作用是MDD病因学的核心。在这方面，最近出现了一种范式转变现象 介绍了通过表位转录机制进行转录后基因调控的独特概念 (最突出的是N6-甲基腺苷[m6A])，它不仅参与转录的调节 丰富，但有深刻的能力影响成熟度、稳定性、本地化，最重要的是可用性 选择的基因转录本到蛋白质的翻译，尽管转录速率不同，但具有高度的动态和 “可逆”时尚。这种机制有助于对外界刺激的快速反应，微调蛋白质 可获得性，并执行局部控制，这对刺激适应性基因表达至关重要。他们的角色 最近在突触可塑性以及小鼠的应激应对行为中被显示出来。我们自己的 初步数据表明，不仅m6A mRNA甲基化机制在 不同的大脑区域，但它们在操纵m6A甲基化和随后的 特定转录本的表达在MDD脑中异常。这导致我们提出了一个最重要的 基于m6A甲基化的mRNAs表位转录修饰可能作为动态调节因子的假说 以大脑区域特定的方式对一组基因进行分析，通过影响特定的分子通路 协调方式，将参与MDD的发病机制。为了测试这一点，在健康的dlPFC和海马体中 对照和匹配良好的MDD受试者，我们提出了以下目标：1)检查MDD是否与 与m6A甲基化机制的不同调节和独特的m6A甲基化图谱在 脑区特异性表位转录水平；2)确定YTH家族读者的MDD相关角色 3)检测m6A基因甲基化对蛋白质表达的影响 树突状细胞在MDD发病机制中的作用。通过使用 高度创新的分子方法，通过精确识别可翻译和 通过检测m6A甲基化的作用，通过特定的m6A阅读器蛋白介导的非翻译池 在Synapse，通过使用新的生物信息学工具分析数据，我们的研究具有很高的创新性；它具有 发现独特的基于表位转录组学的基因调控作为MDD发病机制的可能性 并确定治疗干预的新靶点。

Major depressive disorder (MDD) currently remains one of the leading causes of global disability. Despite the rise in treatment options, remission rates in MDD patients are very low. Thus, there is critical need to identify the biological substrates that precipitate in MDD in order to develop effective therapy. It is widely known that MDD involves short- and long-term maladaptive processes to external stimuli, impairing the ability of individuals to appropriately interact with the environment. So far, there is no coherent hypothesis that can fully explain this phenomenon. Increasing evidence suggests that fine-tuning of transcriptional regulation by gene-environment interaction is central to the etiology of MDD. In this regard, a paradigm shifting phenomenon has recently been introduced with the unique concept of post-transcriptional gene regulation through epitranscriptomic mechanism (most prominently being N6-methyladenosine [m6A]) which is not only involved in the regulation of transcript abundance but has the profound ability to impact maturity, stability, localization, and most importantly, availability of “select” gene transcripts to protein translation despite varying transcription rates in a highly “dynamic” and “reversible” fashion. This mechanism facilitates quick response to external stimuli, fine-tunes protein accessibility, and executes localized control, which is critical to stimulus-adaptive gene expression. Their roles have recently been shown in synaptic plasticity as well as in the stress coping behavior of mice. Our own preliminary data demonstrate that not only is m6A mRNA methylation machinery differentially expressed in various brain areas, but their expression and functions in manipulating m6A methylation and subsequent expression of specific transcripts are aberrant in the MDD brain. This has led us to propose an overarching hypothesis that m6A methylation-based epitranscriptomic modification of mRNAs may act as a dynamic regulator of a subset of genes in a brain region specific manner, which, by affecting specific molecular pathways in a coordinated fashion, will participate in MDD pathogenesis. To test this, in dlPFC and hippocampus from healthy controls and well-matched MDD subjects, we propose the following aims: 1) Examine whether MDD is associated with differential regulation of m6A methylation machinery and distinctive m6A methylation profile at the epitranscriptomic level in brain region specific manner; 2) Define MDD associated role of YTH family of reader proteins in epitranscriptomic turnover of protein coding genes; 3) Examine the impact of m6A mRNA methylation on dendritic availability of local epitranscriptomic pool and their contribution to MDD pathogenesis. By using highly innovative molecular approaches, by precisely identifying the fate of the transcripts in translatable and non-translatable pools mediated through specific m6A reader proteins, by examining the role of m6A methylation at the synapse, and by analyzing data using novel bioinformatics tools, our study is highly innovative; it has the potential to discover unique epitranscriptome-based gene regulation as a mechanism in MDD etiopathogenesis and identify novel targets for therapeutic intervention.