Pumilio: A Novel Target for the Treatment of Epilepsy

• Main Author: Mulroe, Fred P
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2023
• Subjects: Acids; Anticonvulsants; Ataxia; Autism; Bioinformatics; Brain; Cell death; Convulsions & seizures; Disability studies; Drugs; Encephalitis; Epilepsy; Gene expression; Genetics; Genotype & phenotype; Homeostasis; Insects; Mutation; Neurons; Neurosciences; Neurotransmitters; Patients; Physiology; Potassium; Sodium
• ISBN: 9798381855500

Epilepsy is a condition characterised by recurrent seizures. The underlying mechanism of epileptic seizures is excessive and abnormal neuronal activity. Therefore, manipulating firing-rate neuronal homeostasis, mechanisms by which neurons regulate their intrinsic excitability, potentially offers an attractive opportunity to control seizures. Approximately one in three epilepsy cases cannot be controlled with the current option of medication. In order to reduce this number, the discovery of new druggable targets is required. In this project, a combination of both Drosophila and mouse models were used to evaluate the efficacy of a new class of compounds, based on the structure of 4- tert-butylbenzaldehyde. A drug library was created through a combination of purchases and organic synthesis techniques. Screening was performed using Drosophila larvae carrying the parabss mutation, a gain of function mutation in the voltage gated sodium channel of that causes seizure like behaviour. Results from the initial screen showed that the core benzoic acid structure was key to activity. These results were fed in to the design of a 2nd generation of compounds, which resulted in the discovery of a more potent analogue 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoic acid, which was referred to as RAB216 in the library. This compound was tested in various Drosophilaseizure mutants and was found to be effective at reducing seizure recovery times in all those that were tested. In the initial 2 mM screen it reduced recovery times by over 50% and was found to be at least 4x more potent than any other analogue. RAB216 was then taken forward to mouse models, where it was tested in both the PTZ and 6 Hz psychomotor models of seizure. In both models, the compound was found to be efficacious at reducing the severity or time of onset of seizures. Additionally, western blot analysis of mouse brains treated with RAB216, found the levels of the homeostatic regulator, Pum2 were significantly increased by 70%. This study provides proof of principle that targeting neuronal homeostasis is a viable anticonvulsant strategy and identifies a lead compound, which could possibly act as a starting point for future development.