Zhang Yifan, Kecskés Angéla, Copmans Daniëlle, Langlois Mélanie, Crawford Alexander D, Ceulemans Berten, Lagae Lieven, de Witte Peter A M, Esguerra Camila V
Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven, Belgium.
Luxembourg Center for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
PLoS One. 2015 May 12;10(5):e0125898. doi: 10.1371/journal.pone.0125898. eCollection 2015.
Dravet syndrome (DS) is one of the most pharmacoresistant and devastating forms of childhood epilepsy syndromes. Distinct de novo mutations in the SCN1A gene are responsible for over 80% of DS cases. While DS is largely resistant to treatment with existing anti-epileptic drugs, promising results have been obtained in clinical trials with human patients treated with the serotonin agonist fenfluramine as an add-on therapeutic. We developed a zebrafish model of DS using morpholino antisense oligomers (MOs) targeting scn1Lab, the zebrafish ortholog of SCN1A. Zebrafish larvae with an antisense knockdown of scn1Lab (scn1Lab morphants) were characterized by automated behavioral tracking and high-resolution video imaging, in addition to measuring brain activity through local field potential recordings. Our findings reveal that scn1Lab morphants display hyperactivity, convulsive seizure-like behavior, loss of posture, repetitive jerking and a myoclonic seizure-like pattern. The occurrence of spontaneous seizures was confirmed by local field potential recordings of the forebrain, measuring epileptiform discharges. Furthermore, we show that these larvae are remarkably sensitive to hyperthermia, similar to what has been described for mouse models of DS, as well as for human DS patients. Pharmacological evaluation revealed that sodium valproate and fenfluramine significantly reduce epileptiform discharges in scn1Lab morphants. Our findings for this zebrafish model of DS are in accordance with clinical data for human DS patients. To our knowledge, this is the first study demonstrating effective seizure inhibition of fenfluramine in an animal model of Dravet syndrome. Moreover, these results provide a basis for identifying novel analogs with improved activity and significantly milder or no side effects.
德雷维特综合征（DS）是儿童癫痫综合征中最难用药物治疗且最具破坏性的形式之一。SCN1A基因中不同的新生突变导致了超过80%的DS病例。虽然DS对现有抗癫痫药物的治疗大多具有抗性，但在以血清素激动剂芬氟拉明作为附加治疗的人类患者临床试验中已取得了有前景的结果。我们使用靶向scn1Lab（SCN1A的斑马鱼直系同源基因）的吗啉代反义寡聚核苷酸（MOs）构建了一个DS斑马鱼模型。除了通过局部场电位记录测量脑活动外，还通过自动行为跟踪和高分辨率视频成像对scn1Lab反义敲低的斑马鱼幼虫（scn1Lab突变体）进行了表征。我们的研究结果表明，scn1Lab突变体表现出多动、惊厥样癫痫行为、姿势丧失、重复性抽搐和肌阵挛样癫痫模式。通过前脑的局部场电位记录测量癫痫样放电，证实了自发性癫痫的发生。此外，我们表明这些幼虫对热疗非常敏感，这与DS小鼠模型以及人类DS患者的情况相似。药理学评估显示，丙戊酸钠和芬氟拉明可显著减少scn1Lab突变体中的癫痫样放电。我们对这个DS斑马鱼模型的研究结果与人类DS患者的临床数据一致。据我们所知，这是第一项在德雷维特综合征动物模型中证明芬氟拉明有效抑制癫痫发作的研究。此外，这些结果为鉴定具有改善活性且副作用显著减轻或无副作用的新型类似物提供了基础。
