Interleukin-1β plays a role in the pathogenesis of mesial temporal lobe epilepsy through the PI3K/Akt/mTOR signaling pathway in hippocampal neurons

Recently, the role of inflammation in the pathogenesis of mesial temporal lobe epilepsy (MTLE) has garnered great attention. Increasing evidence indicated that interleukin-1 beta (IL-1 beta) plays a critical role in the pathogenesis of MTLE. In this study, we cultured primary hippocampal neurons, using IL-1 beta to mimic the process of inflammatory reaction in neurons, then inhibited the inflammation using inhibitors of the PI3K/Akt/mTOR signaling pathway. The expression of proteins related to the PI3K/Akt/mTOR signaling pathway in rat hippocampal neurons was detected by western blot, and similar methods were applied to the hippocampi obtained from children with MTLE and normal controls. Neuronal somatic size and dendritic length were measured by immunohistochemistry and digital imaging. We observed that stimulation with IL-1 beta in neuron led to the up-regulation of p-Akt and p70S6K and promoted the growth of cell somatic size and dendritic length via the PI3K/Akt/mTOR signaling pathway. Pre-treatment with inhibitors of the pathway, LY294002 and rapamycin, decreased the expression of p-Akt and p70S6K and alleviated the morphological changes induced by IL-1 beta in hippocampal neurons. We further verified the increasement of P-Akt and p70S6K in the hippocampi of children with MTLE. These data are the first to demonstrate that the inflammatory response induced by IL-1 beta promotes seizures and plays an important role in the pathogenesis of MTLE via the PI3K/Akt/mTOR signaling pathway. Therefore, modulation of the PI3K/Akt/mTOR signaling pathway may be a novel therapeutic target for the treatment of MTLE. (C) 2015 Elsevier B.V. All rights reserved.