环状RNA的差异表达对骶神经根性撕脱伤后脊髓前角神经元自噬的影响及其机制研究

The death of neurons in spinal cord anterior horn after sacral nerve root avulsion is one of the key factors affecting the efficacy of sacral nerve repair. In previous studies, we found that neuronal autophagy in spinal anterior horn played an important role in the survival rate of neurons, and hypoxia and inflammatory cytokines participate in this process. Meanwhile, we found that circRNA differential expression existed in neurons of spinal anterior horn after sacral nerve root avulsion by high-throughput sequencing, circRNAs may be involved in the regulation of neuronal autophagy. On the basis of that, we design experiments to further indentify certain circRNAs that may regulate neuronal autophagy in spinal anterior horn after sacral nerve root avulsion, explore the effect of neuronal autophagy modulated by circRNAs and its mechanism， and detect the influence of effect on the survival rate of neurons and its biological significance. In this study, we will not only expand the theory of neuronal autophagy plays a role after sacral nerve root avulsion, but also elucidate the effect and mechanism of circRNAs in autophagy regulation. It is expected to improve the survival rate of neurons in the spinal anterior horn and clinical efficacy for the treatment of sacral nerve root avulsion.

骶神经根性撕脱伤后脊髓前角神经元死亡是影响骶神经修复疗效的关键原因之一。课题组在前期的实验研究中证实自噬是影响脊髓前角神经元存活的重要因素，且与缺氧及炎性因子等关系密切。在此过程中，我们运用高通量测序技术对脊髓前角组织测序后发现，骶神经根性撕脱伤后脊髓前角神经元在发生自噬的同时，存在大量环状RNA差异表达，故我们猜测环状RNA可能参与脊髓前角神经元自噬的调控，国内外未见相关研究报道。本课题拟在此基础上，深入探索并验证参与骶神经根性撕脱伤后脊髓前角神经元自噬调控的具体环状RNA分子，进一步研究其对神经元自噬的作用及机理，并通过分析该作用对损伤环境下神经元存活率的影响，阐明其生物学意义。本研究不仅丰富了自噬参与调控骶神经根性撕脱伤后脊髓前角神经元死亡理论，而且将阐明环状RNA在其中的作用及机制，有望进一步提高神经元存活率，从而改善临床骶神经根性撕脱伤的修复疗效。

研究背景：骶神经根性撕脱伤后脊髓前角神经元死亡是影响骶神经修复疗效的关键原因之一，课题组前期实验发现自噬是影响脊髓前角神经元存活的重要因素，且与环状RNA表达关系密切，但其确切机制仍不清楚。主要研究内容包含：①大鼠骶神经根性撕脱伤后脊髓前角细胞环状RNA高通量测序及自噬相关环状RNA的筛选的实验研究。②自噬相关环状RNA对大鼠骶神经根性撕脱伤后脊髓前角细胞自噬影响的实验研究。③自噬相关环状RNA对大鼠原代脊髓神经元自噬调控的机制研究。重要结果：①通过建立SD大鼠骶神经撕脱伤模型，发现骶神经根性撕脱伤24小时后脊髓前角神经元LC3表达量最高,自噬现象最为明显。②通过大鼠骶神经撕脱伤模型及环状RNA表达变化谱，发现1708个差异表达的环状RNA，其中591个上调,其余1117个下调，进一步通过GO分析、KEGG通路分析和环状RNA/miRNA相互作用网络分析预测脊髓损伤中环状RNA的作用，并发现环状RNAcircRNA_7025可通过调控rno-miR-1224与rno-miR-326-5p缓解神经元OGD损伤。科学意义：本研究不仅丰富了自噬参与调控骶神经根性撕脱伤后脊髓前角神经元死亡理论，而且阐明了环状RNA在其中的作用及机制，有望进一步提高神经元存活率，从而改善临床骶神经根性撕脱伤的修复疗效。