Authors :
Presenting Author: Chiara Tesoriero, PhD – University of Verona
Elena Cannone, PhD student – University of Brescia
Francesca Greco, PhD – University of Verona
Francesco Ghirotto, PhD student – University of Verona
Giorgia Targa, PhD – University of Verona
Marco Cambiaghi, PhD – University of Verona
Andrea Vettori, PhD – University of Verona
Rationale:
Myoclonic-astatic epilepsy (MAE) is a paediatric epilepsy syndrome characterized by a broad spectrum of clinical manifestations, including intellectual disability, behavioural disorders as well as daily frequency of seizures and resistance to pharmacological treatments. Since 2015, autosomal dominant mutations of the gene SLC6A1 – which encodes for the gamma-aminobutyric acid transporter (GAT)-1 - have been widely identified in MAE patients. Despite the progress so far, the pathogenetic mechanisms underlying the SLC6A1 disorders are still unclear.
Methods:
Using an out-of-frame approach, two knockout (KO) mutant zebrafish (Danio rerio) lines - named slc6a1aav1 and slc6a1bav2 – were generated by CRISPR-Cas9 technology. A comprehensive characterization of the experimental model was achieved at the morphological, behavioural and neurophysiological levels. Finally, a target-driven drug screening is undergoing by testing compounds belonging to the family of histone deacetylase (HDAC) inhibitors, known to be active in transcriptional regulation of SLC6A1.
Results:
Although the KO zebrafish animals resulted to be vital, fertile, and able to produce viable offspring, the depletion of 50% of GAT-1 led to a developmental delay as well as to epileptic-like locomotor alterations after light/dark stimuli, either with or without the administration of Pentylenetetrazol. Concerning the drug screening, one-third of the selected HDAC inhibitors have been analysed so far. Interestingly, the exposition of zebrafish embryos to Sodium Phenylbutyrate resulted in a significant augmentation of the wild-type Slc6a1 allele expression, thus partially restoring the physiological condition in the KO animals.
Conclusions:
On this basis, our preclinical animal model may provide a promising tool to identify new potential therapeutical approaches and unveil the pathological mechanisms associated with SLC6A1 alterations.
Funding:
This project is supported by Telethon Foundation (grant number GSA23P001) together with the Slc6a1 connect Italia association.