circ-Phkb在坐骨神经轴突再生修复中的作用机制

Circular RNA (circRNA) is a type of RNA that, unlike linear RNA, forms a covalently closed continuous loop. Recently, circRNAs are found to be highly abundant and conserved in mammalian cells. They have been categorized as non-coding RNA with potential as gene regulators. However, the expression, function and mechanism of circRNAs in nerve injury and repair remain unknown. In this study, we have identified a set of circRNAs differently expressed in dorsal root ganglia (DRGs) by using high-throughput RNA sequencing and bioinformatics analyses. Furthermore, functional assay screening by siRNAs indicated that some of these nerve regeneration-related circRNAs have significant roles in DRG neurons. In this project, we will focus on the function and molecular mechanism of nerve regeneration-related circRNAs in nerve injury and repair, and evaluate the use of circRNAs as new targets.

环状RNA (circular RNA, circRNA)是一类非线性，自身成环的RNA分子，最近研究发现它大量存在于哺乳动物细胞中。作为一类新的调控性非编码RNA，环状RNA在神经损伤修复过程中的存在情况、功能和作用机制都还不清楚。本研究前期工作采用高通量RNA测序，结合生物信息分析，鉴定并筛选出背根神经节(dorsal root ganglion, DRG)组织中差异表达的环状RNA，发现坐骨神经损伤修复过程存在着不少具有一定丰度的差异表达环状RNA；进一步，通过特异siRNA对神经再生相关的环状RNA进行初步的功能筛选，发现有部分的环状RNA在DRG神经元中具有一定的生物学功能。本项目将在前期工作基础上，进一步研究神经再生相关环状RNA (circ-Phkb)在神经损伤修复过程所起的功能和作用机制，探讨环状RNA作为新靶点的应用价值。

环状RNA（circRNA）作为近期新的热门分子，参与机体一系列生理病理过程，而对其调控周围神经再生修复知之甚少。我们采用大鼠坐骨神经夹伤模型，在损伤后不同时间点分别提取DRG和损伤处神经组织，通过RNA-seq、生物信息学分析获得差异表达circRNA；通过PCR和sanger测序确认、circRNA成环鉴定、功能筛选等，确定DRG神经元及施万细胞的功能调控分子。体内外实验发现circ-Spidr在坐骨神经损伤后表达上调并通过PI3K-Akt信号通路促进DRG神经元轴突再生；而神经损伤后circ-Ankib1表达下调通过DHX9-circ-Ankib1-miRNAs-Cyp26b1通路调节施万细胞激活，进而促进神经轴突再生修复。该方面研究扩充了非编码RNA网络在周围神经再生中的调控体系。