Hyperexcitability and Pharmacological Responsiveness of Cortical Neurons Derived from Human iPSCs Carrying Epilepsy-Associated Sodium Channel Nav1.2-L1342P Genetic Variant
| Autor: | Xiaoling Chen, Jean-Christophe Rochet, Chongli Yuan, Layan Yunis, J Marshall Shafer, Maria I. Olivero-Acosta, Muriel Eaton, Zhefu Que, Junkai Xie, Anke M Tukker, Jingliang Zhang, Tiange Xiao, Zhuo Huang, Chang-Deng Hu, Kyle Wettschurack, Jiaxiang Wu, Yang Yang, William C. Skarnes, Aaron B. Bowman, James A. Schaber, Darci J. Trader |
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| Rok vydání: | 2021 |
| Předmět: |
Cerebral Cortex
Gene Editing Neurons Phenytoin Epilepsy NAV1.2 Voltage-Gated Sodium Channel General Neuroscience medicine.medical_treatment Sodium channel Induced Pluripotent Stem Cells Biology medicine.disease Phenotype Bursting Anticonvulsant Mutation NAV1 medicine Humans Induced pluripotent stem cell Neuroscience Research Articles medicine.drug |
| Zdroj: | J Neurosci |
| ISSN: | 1529-2401 0270-6474 |
| DOI: | 10.1523/jneurosci.0564-21.2021 |
| Popis: | With the wide adoption of genomic sequencing in children having seizures, an increasing number ofSCN2Agenetic variants have been revealed as genetic causes of epilepsy. Voltage-gated sodium channel Nav1.2, encoded by geneSCN2A, is predominantly expressed in the pyramidal excitatory neurons and supports action potential (AP) firing. One recurrentSCN2Agenetic variant is L1342P, which was identified in multiple patients with epileptic encephalopathy and intractable seizures. However, the mechanism underlying L1342P-mediated seizures and the pharmacogenetics of this variant in human neurons remain unknown. To understand the core phenotypes of the L1342P variant in human neurons, we took advantage of a reference human-induced pluripotent stem cell (hiPSC) line from a male donor, in which L1342P was introduced by CRISPR/Cas9-mediated genome editing. Using patch-clamping and microelectrode array (MEA) recordings, we revealed that cortical neurons derived from hiPSCs carrying heterozygous L1342P variant have significantly increased intrinsic excitability, higher sodium current density, and enhanced bursting and synchronous network firing, suggesting hyperexcitability phenotypes. Interestingly, L1342P neuronal culture displayed a degree of resistance to the anticonvulsant medication phenytoin, which recapitulated aspects of clinical observation of patients carrying the L1342P variant. In contrast, phrixotoxin-3 (PTx3), a Nav1.2 isoform-specific blocker, can potently alleviate spontaneous and chemically-induced hyperexcitability of neurons carrying the L1342P variant. Our results reveal a possible pathogenic underpinning of Nav1.2-L1342P mediated epileptic seizures and demonstrate the utility of genome-edited hiPSCs as anin vitroplatform to advance personalized phenotyping and drug discovery.SIGNIFICANCE STATEMENTA mounting number ofSCN2Agenetic variants have been identified from patients with epilepsy, but howSCN2Avariants affect the function of human neurons contributing to seizures is still elusive. This study investigated the functional consequences of a recurringSCN2Avariant (L1342P) using human iPSC-derived neurons and revealed both intrinsic and network hyperexcitability of neurons carrying a mutant Nav1.2 channel. Importantly, this study recapitulated elements of clinical observations of drug-resistant features of the L1342P variant, and provided a platform forin vitrodrug testing. Our study sheds light on cellular mechanism of seizures resulting from a recurring Nav1.2 variant, and helps to advance personalized drug discovery to treat patients carrying pathogenicSCN2Avariant. |
| Databáze: | OpenAIRE |
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