The input-output relationship of neuronal networks depends heavily on the intrinsic properties of their neuronal elements.Profound changes in intrinsic properties have been observed in various physiological and pathol...The input-output relationship of neuronal networks depends heavily on the intrinsic properties of their neuronal elements.Profound changes in intrinsic properties have been observed in various physiological and pathological processes,such as learning,memory and epilepsy.However,the cellular and molecular mechanisms underlying acquired changes in intrinsic excitability are still not fully understood.Here,we demonstrate that ERG3 channels are critically involved in the regulation of intrinsic excitability in hippocampal CA1 pyramidal neurons and DG granule cells.Knock-down of ERG3 channels significantly increases neuronal intrinsic excitability,which is mainly caused by decreased fast afterhyperpolarization,delayed time to the generation of an action potential and enhanced summation of somatic excitatory post-synaptic potentials.Interestingly,the expression level of ERG3 protein is significantly reduced in human and mouse brain tissues with temporal lobe epilepsy.Moreover,ERG3 channel knock-down in hippocampus significantly enhanced seizure susceptibility,while mice treated with ERG3 channel activator NS1643 were less prone to epileptogenesis.Taken together,our results suggest ERG3 channels play an important role in determining the excitability of hippocampal neurons and dysregulation of these channels may be involved in the generation of epilepsy.ERG3 channels may thus be a novel therapeutic target for the prevention of epilepsy.展开更多
文摘目的:探究小鼠颞叶癫痫慢性发作期蛋白质功能和信号通路的改变。方法:(1)制备小鼠卡英酸颞叶癫痫模型,行为学达到Racine分级4分判定为造模成功。28 d后,取对照组和实验组小鼠海马组织进行磷酸化蛋白组学实验;(2)选取检出密度大于106的数据进行统计分析;(3)利用GO(Gene Ontology)数据库、KEGG(Kyoto Encyclopedia of Genes and Genomes)数据库和STRING数据库对磷酸化蛋白组学数据进行统计分析;(4)结合文献对组学结果进行分析。结果:(1)质谱共检测出12 697个蛋白质磷酸化位点,其中159个位点变化差异具有统计学意义(P<0.05);(2)在蛋白质功能层面,磷酸化水平显著性变化的蛋白质的分子功能主要是结合(39.5%)和催化活性(35.7%),这些蛋白质参与细胞交流(20.8%)、初级代谢和含磷酸盐化合物代谢等生化过程;(3)在信号通路层面,这些蛋白质参与10条信号转导通路,包括谷氨酸能突触信号通路、Ras信号通路、长时程增强信号通路等;(4)在蛋白质相互作用层面,这些蛋白质形成以Grin1和Dlg3为核心,以Arhgef 2、Arhgap33和Tiam1为核心与以Spnb1/3/4、Add3和Ank2为核心的蛋白质相互作用网;(5)磷酸化蛋白组学数据显示,Grin1、Arhgef2、Arhgap33、Tiam1、Sptbn1/2/4和Ank2等磷酸化水平在癫痫慢性发作期显著升高。结论:磷酸化蛋白组学的结果从蛋白质功能、信号通路和蛋白质相互作用3个层面阐明了小鼠颞叶癫痫慢性发作期海马体蛋白质的变化,验证了磷酸化蛋白组学研究的可靠性,并提示多巴胺功能和Kir3.1钾通道功能可能与癫痫发生相关。
文摘The input-output relationship of neuronal networks depends heavily on the intrinsic properties of their neuronal elements.Profound changes in intrinsic properties have been observed in various physiological and pathological processes,such as learning,memory and epilepsy.However,the cellular and molecular mechanisms underlying acquired changes in intrinsic excitability are still not fully understood.Here,we demonstrate that ERG3 channels are critically involved in the regulation of intrinsic excitability in hippocampal CA1 pyramidal neurons and DG granule cells.Knock-down of ERG3 channels significantly increases neuronal intrinsic excitability,which is mainly caused by decreased fast afterhyperpolarization,delayed time to the generation of an action potential and enhanced summation of somatic excitatory post-synaptic potentials.Interestingly,the expression level of ERG3 protein is significantly reduced in human and mouse brain tissues with temporal lobe epilepsy.Moreover,ERG3 channel knock-down in hippocampus significantly enhanced seizure susceptibility,while mice treated with ERG3 channel activator NS1643 were less prone to epileptogenesis.Taken together,our results suggest ERG3 channels play an important role in determining the excitability of hippocampal neurons and dysregulation of these channels may be involved in the generation of epilepsy.ERG3 channels may thus be a novel therapeutic target for the prevention of epilepsy.
