LncRNA(XLOC_035479)调节TAK1/mTOR/Caspase信号轴介导脊髓神经元“自噬——凋亡对话”促进神经病理性疼痛机制

In recent years, we found that the signaling pathway of TAK1 and mTOR regulate autophagy and apoptosis, both of which are central phenotypes of spinal cord level with neuropathic pain(NP). Instead of complete opposing cell death procedures each other, autophagy and apoptosis perform regulation and transformation with Caspase family as the pivot to precisely regulate the physiological function of body in the way of crosstalk. Nonetheless, puzzles remain as to how the axis of TAK1/mTOR/Caspase mediates crosstalk between autophagy and apoptosis of neurons in spinal cord, which invites systematic and comprehensive study. Recently, we screened out a novel lncRNA (XLOC_035479) with RNA-seq, which were up-regulated in spinal cord in NP rats and were co-expressed and co-localized with TAK1 and mTOR respectively, accompanied by down-regulation of miR-184. Moreover, our prior studies, such as bioinformatic analysis, also validated their immediate interactions. A priori, this project aims to systematically authenticate the hypothesis that the mechanism by which XLOC_035479 inhibits the protein ubiquitination to positive feedback regulates TAK1 and activates mTOR with miR–184 as ceRNA may well reveal the molecular mechanism that XLOC_035479 regulates the axis of TAK1/mTOR/Caspase-mediated crosstalk between autophagy and apoptosis of neurons in the spinal cord so as to facilitate NP.

我们近年研究发现，TAK1和mTOR信号通路介导细胞自噬和凋亡，是神经病理性疼痛（NP）脊髓水平的重要表型。自噬和凋亡并非完全对立的细胞死亡程序，而是通过Caspase家族进行调节、转化，以“对话”的方式精细调控机体的生理功能。TAK1/mTOR/Caspase信号轴如何介导NP脊髓神经元“自噬--凋亡对话”是个新的重要科学问题，需要全面系统研究。最近，我们测序筛选出lncRNA(XLOC_035479)在NP大鼠脊髓中显著上调，分别与TAK1、mTOR共表达、共定位，伴随miR-184的下调，生信分析等前期研究也证实它们存在互作关系。基于此，本项目拟系统证明XLOC_035479通过泛素化修饰正反馈以及与miR-184的ceRNA作用分别调节TAK1和mTOR，从而揭示XLOC_035479调节TAK1/mTOR/Caspase信号轴介导脊髓神经元“自噬--凋亡对话”促进NP的分子机制。

脊髓作为疼痛信息传递和整合的重要初级中枢，在介导和/或维持神经病理性疼痛（Neuropathic pain,NP)中发挥着重要作用。在NP发病过程中，外周伤害性刺激传递到脊髓水平，导致神经元的可塑性及功能改变。其中，细胞自噬和凋亡是NP脊髓水平的重要表型。自噬和凋亡并非对立，而是以Caspase为枢纽“对话”，精细调控细胞的死亡程序。TAK1和mTOR分别是目前已知的调控细胞自噬和凋亡的重要靶点，与我们测序新发现的lncRNA(XLOC_035479)共表达、共定位，三者表达的增加伴随miR-184下调。基于此，本课题已完成的研究系统证明了XLOC_035479通过ceRNA机制作用miR-184激活mTOR，调控氧化应激和细胞自噬的机制。在此基础上，我们成功申报并筹建了广州市重点实验室《脊髓水平神经病理性疼痛机制研究实验室》。紧密围绕课题研究方向，我们进一步探究了双孔钾离子通道TRESK调控自噬介导NP的作用机制；通过生信分析明确了NP脊髓水平后续研究的重要靶点基因；综述了lncRNA和miRNA参与调控脊髓水平NP的作用机制以及泛素化修饰在慢性疼痛中的重要作用，为今后延续本课题深入探讨脊髓水平NP的作用机制奠定基础。