Up-regulated cytoplasmic FMRP-interacting protein 1 in intractable temporal lobe epilepsy patients and a rat model

Cytoplasmic FMRP-interacting protein 1 (CYFIP1) is a multifunctional protein which expresses highly at excitatory synapses and can locally regulate actin cytoskeletal dynamics, spine morphology and synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor lateral diffusion. Altered synaptic actin plays a role in the pathogenesis of epilepsy. The aim of this study was to investigate the expression pattern of CYFIP1 in temporal lobe epilepsy (TLE). Protein and mRNA expression levels were compared in temporal lobe tissue from patients with TLE versus trauma patients without TLE using quantitative real-time polymerase chain reaction (qRT-PCR), double-label immunofluorescence and Western blot analysis. We have further determined the expression pattern of Cyfip1 mRNA and protein in the hippocampus and adjacent cortex of a common rat model of TLE, lithium-pilocarpine treatment, compared to control rats. CYFIP1 expression was significantly up-regulated in the temporal neocortex of patients with intractable TLE and pilocarpine-treated rats compared to control groups. CYFIP1 localizes to the cytoplasm of neurons, and is not expressed in the astrocytes. Furthermore, CYFIP1 expression levels increased significantly in the two months after pilocarpine treatment, which corresponds to the period of epileptogenesis. Thus, our results indicate that CYFIP1 may be involved in the pathogenesis of TLE.