A potassium leak channel silences hyperactive neurons and ameliorates status epilepticus

Authors

  • Deblina Dey,

    1. Department of Pharmacology, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
    2. Department of Neuroscience, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
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  • Veit-Simon Eckle,

    1. Department of Pharmacology, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
    Current affiliation:
    1. Department of Anesthesiology & Intensive Care, Eberhard-Karls-University, Tübingen, Germany
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  • Iuliia Vitko,

    1. Department of Pharmacology, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
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  • Kyle A. Sullivan,

    1. Department of Pharmacology, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
    2. Undergraduate School of Arts and Sciences, University of Virginia, Charlottesville, Virginia, U.S.A
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  • Zofia M. Lasiecka,

    1. Department of Neuroscience, Virginia School of Medicine, Charlottesville, Virginia, U.S.A
    Current affiliation:
    1. Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, New York, U.S.A
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  • Bettina Winckler,

    1. Department of Neuroscience, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
    2. Department of Neuroscience, Virginia School of Medicine, Charlottesville, Virginia, U.S.A
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  • Ruth L. Stornetta,

    1. Department of Pharmacology, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
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  • John M. Williamson,

    1. Department of Neurology, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
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  • Jaideep Kapur,

    1. Department of Neuroscience, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
    2. Department of Neurology, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
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  • Edward Perez-Reyes

    Corresponding author
    1. Department of Pharmacology, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
    2. Department of Neuroscience, Graduate Program University of Virginia School of Medicine, Charlottesville, Virginia, U.S.A
    • Address correspondence to Edward Perez-Reyes, Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, U.S.A. E-mail: eperez@virginia.edu

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Summary

Objective

To develop a constitutively active K+ leak channel using TREK-1 (TWIK-related potassium channel 1; TREK-M) that is resistant to compensatory down-regulation by second messenger cascades, and to validate the ability of TREK-M to silence hyperactive neurons using cultured hippocampal neurons. To test if adenoassociated viral (AAV) delivery of TREK-M could reduce the duration of status epilepticus and reduce neuronal death induced by lithium-pilocarpine administration.

Methods

Molecular cloning techniques were used to engineer novel vectors to deliver TREK–M via plasmids, lentivirus, and AAV using a cytomegalovirus (CMV)-enhanced GABRA4 promoter. Electrophysiology was used to characterize the activity and regulation of TREK–M in human embryonic kidney (HEK-293) cells, and the ability to reduce spontaneous activity in cultured hippocampal neurons. Adult male rats were injected bilaterally with self-complementary AAV particles composed of serotype 5 capsid into the hippocampus and entorhinal cortex. Lithium-pilocarpine was used to induce status epilepticus. Seizures were monitored using continuous video–electroencephalography (EEG) monitoring. Neuronal death was measured using Fluoro-Jade C staining of paraformaldehyde-fixed brain slices.

Results

TREK-M inhibited neuronal firing by hyperpolarizing the resting membrane potential and decreasing input resistance. AAV delivery of TREK-M decreased the duration of status epilepticus by 50%. Concomitantly it reduced neuronal death in areas targeted by the AAV injection.

Significance

These findings demonstrate that TREK-M can silence hyperexcitable neurons in the brain of epileptic rats and treat acute seizures. This study paves the way for an alternative gene therapy treatment of status epilepticus, and provides the rationale for studies of AAV-TREK-M's effect on spontaneous seizures in chronic models of temporal lobe epilepsy.

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