Sun Yishan, Paşca Sergiu P, Portmann Thomas, Goold Carleton, Worringer Kathleen A, Guan Wendy, Chan Karen C, Gai Hui, Vogt Daniel, Chen Ying-Jiun J, Mao Rong, Chan Karrie, Rubenstein John Lr, Madison Daniel V, Hallmayer Joachim, Froehlich-Santino Wendy M, Bernstein Jonathan A, Dolmetsch Ricardo E
Novartis Institutes for BioMedical Research, Cambridge, United States.
Department of Neurobiology, Stanford University School of Medicine, Stanford, United States.
Elife. 2016 Jul 26;5:e13073. doi: 10.7554/eLife.13073.
Dravet Syndrome is an intractable form of childhood epilepsy associated with deleterious mutations in SCN1A, the gene encoding neuronal sodium channel Nav1.1. Earlier studies using human induced pluripotent stem cells (iPSCs) have produced mixed results regarding the importance of Nav1.1 in human inhibitory versus excitatory neurons. We studied a Nav1.1 mutation (p.S1328P) identified in a pair of twins with Dravet Syndrome and generated iPSC-derived neurons from these patients. Characterization of the mutant channel revealed a decrease in current amplitude and hypersensitivity to steady-state inactivation. We then differentiated Dravet-Syndrome and control iPSCs into telencephalic excitatory neurons or medial ganglionic eminence (MGE)-like inhibitory neurons. Dravet inhibitory neurons showed deficits in sodium currents and action potential firing, which were rescued by a Nav1.1 transgene, whereas Dravet excitatory neurons were normal. Our study identifies biophysical impairments underlying a deleterious Nav1.1 mutation and supports the hypothesis that Dravet Syndrome arises from defective inhibitory neurons.
德拉韦综合征是一种难治性儿童癫痫，与编码神经元钠通道Nav1.1的基因SCN1A中的有害突变有关。早期使用人类诱导多能干细胞（iPSC）的研究对于Nav1.1在人类抑制性神经元与兴奋性神经元中的重要性得出了不一致的结果。我们研究了在一对患有德拉韦综合征的双胞胎中鉴定出的一种Nav1.1突变（p.S1328P），并从这些患者中生成了iPSC衍生的神经元。对突变通道的表征显示电流幅度降低以及对稳态失活的超敏反应。然后，我们将德拉韦综合征患者和对照的iPSC分化为端脑兴奋性神经元或内侧神经节隆起（MGE）样抑制性神经元。德拉韦综合征抑制性神经元表现出钠电流和动作电位发放缺陷，而Nav1.1转基因可挽救这些缺陷，而德拉韦综合征兴奋性神经元则正常。我们的研究确定了有害Nav1.1突变背后的生物物理损伤，并支持德拉韦综合征源于抑制性神经元缺陷的假说。
