Drug-Inducible Gene Therapy Effectively Reduces Spontaneous Seizures in Kindled Rats but Creates Off-Target Side...

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Temporal lobe epilepsy (TLE) affects over a third of patients, necessitating novel treatments beyond current anti-seizure drugs.
• Gene therapy using adeno-associated viral vectors (AAV) offers a promising avenue, but lacks regulated expression and faces challenges with narrow therapeutic windows.

Purpose of the Study:

• To develop and evaluate a first-generation doxycycline-regulated gene therapy for TLE.
• To investigate the therapeutic potential and safety of delivering an engineered potassium channel (TREK-M) via AAV.

Main Methods:

• AAV vectors carrying doxycycline-regulated TREK-M were injected into the hippocampus of male rats.
• Rats underwent electrical kindling, and EEG was monitored for seizure activity.
• Localization studies assessed AAV expression in different neuron types.

Main Results:

• Low TREK-M expression without doxycycline induced spontaneous seizures, linked to expression in GABAergic neurons.
• Doxycycline administration reduced seizures by increasing TREK-M expression in excitatory neurons.
• These findings underscore the critical importance of evaluating AAV gene therapy localization and potential side effects.

Conclusions:

• Drug-inducible gene therapy, specifically with doxycycline-regulated TREK-M, can effectively reduce seizures in a TLE model.
• Unintended expression of therapeutic genes can have pro-epileptic effects, emphasizing the need for rigorous preclinical safety assessments.
• Targeting specific neuronal populations is crucial for optimizing AAV-based gene therapy efficacy and safety in epilepsy treatment.