Targeted overexpression of glutamate transporter-1 reduces seizures and attenuates pathological changes in a mouse model of epilepsy

Neurobiol Dis. 2021 Sep:157:105443. doi: 10.1016/j.nbd.2021.105443. Epub 2021 Jul 9.

Abstract

Astrocytic glutamate transporters are crucial for glutamate homeostasis in the brain, and dysregulation of these transporters can contribute to the development of epilepsy. Glutamate transporter-1 (GLT-1) is responsible for the majority of glutamate uptake in the dorsal forebrain and has been shown to be reduced at epileptic foci in patients and preclinical models of temporal lobe epilepsy (TLE). Current antiepileptic drugs (AEDs) work primarily by targeting neurons directly through suppression of excitatory neurotransmission or enhancement of inhibitory neurotransmission, which can lead to both behavioral and psychiatric side effects. This study investigates the therapeutic capacity of astrocyte-specific AAV-mediated GLT-1 expression in the intrahippocampal kainic acid (IHKA) model of TLE. In this study, we used Western blot analysis, immunohistochemistry, and long-term-video EEG monitoring to demonstrate that cell-type-specific upregulation of GLT-1 in astrocytes is neuroprotective at early time points during epileptogenesis, reduces seizure frequency and total time spent in seizures, and eliminates large behavioral seizures in the IHKA model of epilepsy. Our findings suggest that targeting glutamate uptake is a promising therapeutic strategy for the treatment of epilepsy.

Keywords: AAV; Astrocyte; Epilepsy; GLT-1; Glutamate transporter-1; Kainic acid; Seizure.

MeSH terms

  • Animals
  • Astrocytes / metabolism*
  • Disease Models, Animal
  • Electroencephalography
  • Epilepsy, Temporal Lobe / chemically induced
  • Epilepsy, Temporal Lobe / genetics*
  • Epilepsy, Temporal Lobe / metabolism
  • Epilepsy, Temporal Lobe / physiopathology
  • Excitatory Amino Acid Agonists / toxicity
  • Excitatory Amino Acid Transporter 2 / genetics*
  • Gene Knock-In Techniques
  • Hippocampus / metabolism*
  • Kainic Acid / toxicity
  • Mice
  • Seizures / chemically induced
  • Seizures / genetics*
  • Seizures / metabolism
  • Seizures / physiopathology
  • Up-Regulation

Substances

  • Excitatory Amino Acid Agonists
  • Excitatory Amino Acid Transporter 2
  • Slc1a2 protein, mouse
  • Kainic Acid