AOCCN2017

講演情報

Poster Presentation

[P1-1~141] Poster Presentation 1

2017年5月11日(木) 09:30 〜 16:00 Poster Room A (1F Navis A・B・C)

[P1-95] Isogenic iPSCs from an individual with SCN1A mutation mosaicism revealed aberrant dopamine levels in Dravet syndrome neurons

Hiroshi Maeda (Department of Pediatrics, Kyoto Prefectural University of Medicine, Kyoto, Japan)

[Background] Dravet syndrome (DS) is a severe childhood epilepsy typically caused by de novo dominant mutations in SCN1A, encoding for the voltage-gated sodium channel Nav1.1. Although DS is associated with severe cognitive and behavioral impairments, the precise pathophysiology of them has not been elucidated. There are wide phenotypic differences among individuals with SCN1A mutations, suggesting that the existence of genetic factors other than SCN1A mutation modify the phenotype. Therefore, well controlled cellular model system is required to improve our understanding of the mechanisms underlying DS.
[Methods] We generated induced pluripotent stem cell (iPSC) lines from an individual with SCN1A mutation mosaicism and separately cloned iPSC lines both with and without SCN1A mutation (DS and Wild-Type (WT), respectively). These clones theoretically have the same genetic backgrounds, except for the SCN1A gene, and should serve as an ideal pair for elucidating the pathophysiology caused by SCN1A mutation. Then we performed in vitro neuronal differentiation.
[Results] Quantitative RT-PCR and western blot analysis revealed that both TH mRNA and TH protein expression levels of DS-derived neurons were higher than that of WT-derived neurons. Moreover, dopamine concentrations in media collected from DS-derived neuronal cultures were higher than that from WT-derived neuronal cultures.
[Conclusion] This model enables us to investigate the neurobiology of DS throughout the stages of neurodevelopment. SCN1A mutation leads to changes in the dopamine system that may contribute to the behavioral abnormalities in DS.