环状RNA GRIN2B通过NF-κB调控SLICK在坐骨神经痛中的功能和机制研究

Neuronal excitation abnormalities caused by the imbalance of SLICK potassium channel is important cause of sciatica, and NF-κB pathway regulated by the tumor necrosis factor TNFα is one of the key mechanisms for sciatica. Some studies indicated that NF-κB pathway can regulate SLICK expression, but its concrete mechanism hasn’t been clearly known. The early appraisal of study team showed that circRNA GRIN2B can affect the excitation of dorsal root ganglion (DRG) and expression of SLICK, covers the conservative binding site of NF-κB and binds with NF-κB. Thus, it can be speculated that circGRIN2B can boost SLICK transcriptional expression and suppress DRG excitation by recruiting the transcription factor NF-κB, to relieve the sciatica. We will perform experiments on somatic animals and in-vitro cells, to discuss the function of circGRIN2B in affecting neuronal excitability and sciatica, and study the acting mechanism of circGRIN2B in regulation of NFκB transcription factor on SLICK expression, to provide the new theoretical basis for treatment of sciatica.

SLICK钾通道表达失调所致神经元兴奋异常是坐骨神经痛的重要原因，肿瘤坏死因子TNFα调控的NF-κB通路是坐骨神经痛的关键机制之一，研究报道称NF-κB通路可调控SLICK表达，但具体机制不明。研究团队前期鉴定发现环状RNA circGRIN2B可影响背根神经节（DRG）兴奋性和SLICK表达，含有NF-κB的保守结合位点并与NF-κB结合。据此我们推测：circGRIN2B通过招募转录因子NF-κB促进SLICK的转录表达，抑制DRG兴奋性从而缓解坐骨神经痛。研究团队将通过在体动物和体外细胞实验探索circGRIN2B在影响神经元兴奋性以及坐骨神经痛中的功能，并重点研究circGRIN2B在NFκB转录调控SLICK表达中的作用机理，为坐骨神经痛治疗提供新的理论依据。

坐骨神经痛是由多种原因引起的常见和难治性疾病，临床上缺乏相应治疗手段，其原因主要是坐骨神经痛的基因调控机制仍不清楚。circRNA丰富表达于神经系统，是基因表达调控新方式。本课题从整体、细胞及分子水平围绕"circRNA GRIN2B/NF-κB/SLICK影响背根神经节细胞（DRG）的兴奋性来调控坐骨神经痛机制"的科学假设。主要研究内容为：目标circRNA GRIN2B的筛选、表征及其调控坐骨神经痛；在炎症环境下，circRNA GRIN2B携带NF-κB入核，增强SLICK靶基因的转录，抑制DRG兴奋性并调控疼痛。本课题重要结果展示：IL-1β诱导DRG后，circRNA GRIN2B表达显著上调表达。通过将慢病毒包装的shRNA感染DRG以敲除circRNA GRIN2B表达，外向钠激活的钾电流（Ik）显著降低，动作电位的频率增加。同时，我们还发现circRNA GRIN2B沉默可以降低机械和热痛阈。在机制上，我们发现circRNA GRIN2B在DRG细胞质和细胞核中均有表达，在IL-1β刺激下，细胞质内的circRNA GRIN2B结合转录因子NF-κB入细胞核的机制调控SLICK。此外，课题相关延伸研究还探讨并揭示了环状RNA可通过粘着斑和代谢信号通路影响坐骨神经痛的发生和发展（J Oncol. 2022 Aug 27; 2022:7246904）。本课题的完成将有助于阐明环状RNA参与调控坐骨神经痛的分子机制，为基于cirRNA及表观遗传修饰用于坐骨神经痛临床治疗提供新的治疗靶点和理论依据。