用于细胞内微小核糖核酸动态化学修饰过程研究的探针分子构建及应用

MicroRNAs are intracellular small non-coding RNAs that are able to regulate gene expression at the post-transcriptional level. MicroRNAs play important roles in physiological processes. Abberant expression or functional of miRNAs was found to be closely related to the occurrance of various diseases. Chemical modification on miRNAs was known to affect the stability and function of miRNAs. However, chemical biological studies on the chemical modification processes of miRNAs are still preliminary due to the lack of appropriate molecular probes which remain the biological function of intact miRNAs. We propose here to construct functional miRNA probes using bio-orthogonal or bio-compatible functionalities to modify miRNA without changing their intracellular functions. Upon transfection of these functional probes into live cells, the same chemical modification process is supposed to happen on them as that happens on the intact miRNAs. Then it is possible to use bio-orthogonal reactions to post-label the biomacromolecules that bind with the function probe and regulate the chemical modification process for further analysis and identification. We propose to elucidate the mechanism of miRNA modification using typical chemical biological methods based on these functional miRNA probes. Meanwhile, we hope to reveal some of the important roles of miRNA chemical modification in specific disease pathology through the interdisciplanary research based on these functional miRNA probes.

微小核糖核酸是细胞中一类具有在转录后调控基因表达功能的非编码核糖核酸，在生物体的正常生理活动中起重要调控作用，在多种疾病中也发现其异常的表达或活性。对细胞内微小核糖核酸的化学修饰方面的研究目前还处于初级阶段，功能探针分子的匮乏是目前限制在分子层面对微小核糖核酸化学修饰开展研究的重要因素。本项目在已有的研究基础之上提出基于生物正交或生物相容官能团对微小核糖核酸的修饰构建功能探针分子，在探针分子进入细胞内发生正常微小核糖核酸所经历的化学修饰过程之中或之后，综合利用生物正交反应等化学生物学方法对与微小核糖核酸化学修饰过程中的生物大分子进行捕捉、分析和鉴定，以揭示细胞内微小核糖核酸化学修饰的化学及分子机制，同时通过与特定生理病理过程的相关性研究揭示不同的微小核糖核酸化学修饰在特定的生理病理进程中所起的关键作用。

微小核糖核酸是一类细胞内源的基因表达调节分子，在生理病理过程中发挥着核心作用。以微小核糖核酸作为研究靶标，本项目通过发展新型生物正交化学工具针对细胞内微小核糖核酸开展了一系列化学生物学研究，具体包括：（一）发展了新型可见光诱导的生物正交反应，实现了活细胞内生物分子的时空分辨标记以及细胞内微小核糖核酸的调控；（二）发展了具有近红外荧光性质的分子骨架，并探索了其在微小核糖核酸等生物大分子标记中的应用；（三）发展了光敏型微小核糖核酸探针，并探索了其在细胞内微小核糖核酸功能调控和靶基因鉴定中的应用；（四）结合光诱导的生物正交反应构建功能短肽实现了微小核糖核酸的靶向运输和肿瘤治疗。这些研究成果为针对微小核糖核酸的化学生物学研究提供了新的工具或方法，也将为针对微小核糖核酸的疾病治疗提供新的工具或理论基础。基于这些研究成果，本项目在J. Am. Chem. Soc.等国际期刊上总计发表SCI论文七篇。