PUBLICATION

Pharmacological Characterization of an Antisense Knockdown Zebrafish Model of Dravet Syndrome: Inhibition of Epileptic Seizures by the Serotonin Agonist Fenfluramine

Authors
Zhang, Y., Kecskés, A., Copmans, D., Langlois, M., Crawford, A.D., Ceulemans, B., Lagae, L., de Witte, P.A., Esguerra, C.V.
ID
ZDB-PUB-150513-4
Date
2015
Source
PLoS One   10: e0125898 (Journal)
Registered Authors
Crawford, Alexander, Esguerra, Camila V.
Keywords
Larvae, Zebrafish, Swimming, Biological locomotion, Embryos, Graphs, Morpholino, Phenotypes
MeSH Terms
  • Animals
  • Anticonvulsants/administration & dosage
  • Anticonvulsants/therapeutic use
  • Disease Models, Animal
  • Epilepsies, Myoclonic/drug therapy*
  • Epilepsies, Myoclonic/genetics*
  • Epilepsies, Myoclonic/pathology
  • Fenfluramine/administration & dosage*
  • Fenfluramine/therapeutic use
  • Gene Knockdown Techniques
  • Humans
  • Morpholinos/metabolism
  • NAV1.1 Voltage-Gated Sodium Channel/genetics*
  • NAV1.1 Voltage-Gated Sodium Channel/metabolism
  • Oligonucleotides, Antisense/metabolism
  • Selective Serotonin Reuptake Inhibitors/administration & dosage*
  • Selective Serotonin Reuptake Inhibitors/therapeutic use
  • Valproic Acid/administration & dosage
  • Valproic Acid/therapeutic use
  • Zebrafish
  • Zebrafish Proteins/genetics*
  • Zebrafish Proteins/metabolism
PubMed
25965391 Full text @ PLoS One
Abstract
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.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping