Proteomic Profiling of the Hippocampus of Rats Subjected to the Pilocarpine Model of Epilepsy

Background/Objectives: High doses of pilocarpine to rats induce status epilepticus (SE) and reproduce the main characteristics of mesial temporal epilepsy. This model is considered highly isomorphic with the human disease, reason why it has been applied to elucidate the process of epileptogenesis. Methods: Two-dimensional electrophoresis (2-DE) was employed to study the hippocampal differential expression of proteins in rats exhibiting spontaneous recurrent seizures induced by pilocarpine. Two groups were studied: rats treated with pilocarpine (360mg/kg, N=6), and rats treated with saline (N=6). Both groups were analyzed 90 days after SE onset. Hippocampi homogenized in a lysis buffer were used to perform 2-DE. Interactome for differentially expressed proteins was performed using STRING database. Results: Protein spots analyzed by PDQuest software revealed forty proteins differentially expressed in epileptic rats compared to control (p< 0.05), among them thirty-seven were successfully identified. LC-ESI-MS/MS results analyzed with MASCOT MS/MS ion search and IPI protein database showed twenty-nine up-regulated proteins in epileptic rats while six proteins were down-regulated and two proteins were expressed only in the control animals. The differentially expressed proteins integrated the domains of neuronal hyperexcitability, energy failure, synaptic dysregulation, and post-status epilepticus remodeling (confidence scores ≥0.90–0.99). Conclusions: The differentially expressed proteins showed high-confidence protein-protein interaction modules directly linked to the molecular pathogenesis of epilepsy. The simultaneous failure of the identified pathophysiological domains drives the transition from acute seizures to chronic, drug-refractory epilepsy. The protein complexes identified represent high-value, translation-ready candidate nodes for next-generation antiepileptogenic and disease-modifying therapies.