miR-340对背根神经节神经元兴奋性和钠通道电流的作用  

Effects of miR-340 on excitability and sodium currents in cultured DRG neurons

作　　者：马颂华[1] 邢玲燕 苏文凤[2] 陈罡 MA Songhua;XING Lingyan;SU Wenfeng;CHEN Gang(Medical School,Nantong University,Jiangsu 226001;Jiangsu Key Laboratory of Neuroregeneration,Nantong University,Jiangsu 226001)

机构地区：[1]南通大学医学院,江苏226001 [2]南通大学江苏省神经再生重点实验室,江苏226001

出　　处：《交通医学》2020年第5期441-443,447,共4页Medical Journal of Communications

基　　金：国家自然科学基金面上项目(31872773);南通市科技项目(JC2018083)。

摘　　要：目的:观察miR-340对小鼠背根神经节神经元兴奋性和电压依赖性钠通道电流的作用。方法:采用全细胞膜片钳技术记录神经元放电和钠通道电流。结果:在给予miR-340-3p前DRG神经元的膜静息电位为-49.50±4.76 mV,灌流miR-340-3p后膜的静息电位为-52.13±5.32 mV,差异无统计学意义(P>0.05),提示miR-340未影响神经元静息膜电位。在给予miR-340-3p前诱发动作电位数为1.8±0.75个,灌流miR-340-3p后诱发动作电位数为5.6±0.51个,差异具有统计学意义(P<0.05),提示miR-340可增高神经元诱发放电频率。电流-电压曲线表明在激活电压从-30 mV至0 mV时,miR-340-3p明显增加钠通道电流密度,差异具有统计学意义(P<0.05)。激活曲线也表明,miR-340-3p使钠通道激活曲线左移,半激活电压从-22.6 mV增加至-27.4 mV。结论:miR-340对背根神经节神经元的兴奋作用可能是介导坐骨神经损伤神经病理性疼痛的机制之一。Objective:To investigate the effects of miR-340 on excitability and voltage-dependent sodium channel(VDSC)in mouse dorsal root ganglion(DRG)neurons.Methods:Sodium currents and evoked firing were recorded by whole-cell voltage clamp and current clamp configuration in cultured small DRG neurons.Results:The resting potential of DRG neurons was-49.50±4.76 mV and-52.13±5.32 mV before and after miR-340-3p application,indicating miR-340 had no effect on resting potential.While the number of evoked action potential was from 1.8±0.75 to 5.6±0.51,which has significant difference,showing miR-340 increased firing rate.Meanwhile,current-voltage curve showed miR-340-3p significantly increased the sodium channel current density between-30 mV and 0 mV.In addition,the activation curve shifted left and the semi active voltage ranged from-22.6 mV to-27.4 mV after application of miR-340-3p.Conclusions:The excitatory effect of miR-340 on DRG neurons might be one of the mechanisms which contribute to neuropathic pain during sciatic nerve injury.

关 键 词：miR-340 电压依赖性钠通道 背根神经节 神经病理性疼痛 

分 类 号：Q424[生物学—神经生物学]