蛛网膜下隙注射miR-30b对脊髓Nav1.3表达及神经病理性疼痛的影响
Effect of intrathecal injection of miR-30b on expression of Nav1.3 in rat spinal cord and neuropathic pain

目的:探讨神经病理性疼痛发展期间电压门控钠离子通道亚型1.3(Nav1.3)在脊髓高表达的机制是否与miR-30b相关以及蛛网膜下隙注射miR-30b能否缓解神经病理性疼痛。方法:利用双荧光素酶报告基因检测miR-30b与编码Nav1.3的基因Scn3A的3'UTR是否直接作用; 利用大鼠制作脊神经结扎(SNL)神经病理性疼痛模型; 通过测定机械刺激痛阈值及热痛阈值检测大鼠痛行为学的改变; 利用Western blot 检测脊髓背角Nav1.3的蛋白表达; 利用qPCR检测脊髓背角Scn3A mRNA的表达。结果:miR-30b直接作用于Scn3A的3'UTR区,负调控Scn3A的表达; Nav1.3蛋白在SNL大鼠脊髓背角组织中高表达; 蛛网膜下隙注射miR-30b可以翻转SNL大鼠的机械刺激痛阈值及热痛阈值的下降,同时翻转SNL大鼠脊髓背角组织中Nav1.3的高表达。结论:神经病理性疼痛发展期间miR-30b的下调导致Nav1.3在脊髓高表达,蛛网膜下隙注射 miR-30b可抑制Nav1.3的表达,并且缓解疼痛。
Aim: To explore whether the mechanism of voltage-gated sodium channels subtype Nav1.3 upregulation in the spinal cord is regulated by miR-30b and whether intrathecal injection of miR-30b could alleviate neuropathic pain.Methods: The dual luciferase assay was used to detect the relationship between miR-30b and the 3'UTR of Scn3A which encoded Nav1.3.Spinal nerve ligation(SNL)neuropathic pain model was made in rats.The behavioral changes of rats were detected by mechanical stimulus threshold test and thermal withdrawal latency test.The expression of Nav1.3 protein in spinal cord of rats was examined by Western blot,and qPCR was used to detect the expressions of Scn3A mRNA.Results: miR-30b directly targeted Scn3A 3'UTR and negatively regulated Scn3A expression. The expression of Nav1.3 was raised in the spinal cord of rats with SNL. Intrathecal injection of miR-30b could reverse the decrease of the mechanical stimulus threshold and thermal withdrawal latency of SNL rats, and reverse the up-regulation of Nav1.3 in the spinal cord of SNL rats.Conclusion: The down-regulation of miR-30b could induce the increase of Nav1.3 in the spinal cord in stage of neuropathic pain development. Intrathecal injection of miR-30b could inhibit the expression of Nav1.3 and relieve the pain