Development of novel research tools and a database for mapping human mitochondrial tRNA modifications by mass spectrometry

总结 在这个快速通道I/II期STTR项目中，将开发一种新的质谱分析方法和配套试剂盒， 开发用于绘制人类线粒体转移RNA（mt-tRNA）中的修饰核苷酸，包括 最丰富的修饰，假尿苷，迄今已被证明是一个技术挑战，因为它是 尿苷的异构体。这些新的研究工具将被用来建立第一个修改数据库 来自10名正常受试者和20名患有线粒体疾病的患者的所有22种人类mt-tRNAs的图谱， 患有中枢神经系统（CNS）疾病。 该项目的第一阶段将涉及开发一种用于特定地点的质谱分析方法。 MT-tRNA中的假尿苷和其它核苷酸修饰的定量（Aim 1）和用于 从实际量的人组织和细胞系中分离线粒体（目的2）。第二阶段将涉及 从线粒体中分离人mt-tRNAs的方法的开发（目的3）， 对来自健康受试者的正常mt-tRNAs进行定位（目的4），以及对异常mt-tRNAs中的修饰进行定位。 来自具有CNS病症的线粒体疾病患者的tRNA（目的5）。由此产生的数据库超过 600个mt-tRNA修饰图谱将为线粒体之间的分子联系提供有价值的见解。 功能障碍和CNS病症，包括由生理损伤如药物滥用引起的那些。 该项目的成功将使第三阶段的产品开发和采矿工作得以完成。 MT-tRNA上的临床生物标志物和药物靶点的修饰数据库，用于发现小分子 识别异常修饰结构的精确药物。这种新型药物将 旨在选择性地终止蛋白质合成，并剔除异常线粒体，于是健康的 线粒体将自动地重新填充细胞并恢复正常的CNS功能。 这项工作将作为RiboNova、辛辛那提大学和 费城儿童医院，他们拥有分子生物学的相关资源和专业知识， 光谱和线粒体医学，分别完成项目目标。

Summary In this fast-track Phase I/II STTR project, a novel mass spectrometry method and a matched reagent kit will be developed for mapping modified nucleotides in human mitochondrial transfer RNA (mt-tRNA), including the most abundant modification, pseudouridine, which hitherto has proved to be a technical challenge because it is an isomer of uridine. These new research tools will be harnessed to build the first database of modification maps for all 22 human mt-tRNAs from ten normal subjects and twenty patients with mitochondrial disease who have disorders of the central nervous system (CNS). Phase I of this project will involve the development of a mass spectrometry method for the site-specific quantification of pseudouridine and other nucleotide modifications in mt-tRNAs (Aim 1) and a method for isolating mitochondria from practical quantities of human tissues and cell lines (Aim 2). Phase II will involve the development of a method for isolating human mt-tRNAs from mitochondria (Aim 3), the modification mapping of normal mt-tRNAs from healthy subjects (Aim 4), and the mapping of modifications in abnormal mt- tRNAs from mitochondrial disease patients with CNS disorders (Aim 5). The resulting database of more than 600 mt-tRNA modification maps will provide valuable insights into the molecular links between mitochondrial dysfunction and CNS disorders, including those caused by physiological insults such as drug abuse. Success in this project will enable the Phase III completion of product development and mining of the modification database for clinical biomarkers and drug targets on mt-tRNAs for the discovery of small-molecule precision medicines that recognize the abnormal modification structures. This new class of drugs will be designed to selectively terminate protein synthesis in, and cull, abnormal mitochondria, whereupon the healthy mitochondria will automatically repopulate the cell and restore normal CNS function. This work will be conducted as a collaborative project between RiboNova, the University of Cincinnati, and The Children's Hospital of Philadelphia, who have the relevant resources and expertise in molecular biology, mass spectrometry and mitochondrial medicine, respectively, to accomplish the project goals.