Research ReportUp-regulated ephrinB3/EphB3 expression in intractable temporal lobe epilepsy patients and pilocarpine induced experimental epilepsy rat model

•Abnormal ephrinBs and EphBs mRNA expression were observed in patients and rats with intractable temporal lobe epilepsy (TLE).•ephrinB3 and EphB3 were up-regulated in intractable TLE patients and rats.•ephrinB3 located in both glia and neurons, EphB3 located in neurons.•ephrinB3 and EphB3 may serve as potential biomarkers for predicting TLE.

EphB family receptor tyrosine kinases, in cooperation with cell surface-bound ephrinB ligands, play a critical role in maintenance of dendritic spine morphogenesis, axons guidance, synaptogenesis, synaptic reorganization and plasticity in the central nervous system (CNS). However, the expression pattern of ephrinB/EphB in intractable temporal lobe epilepsy (TLE) and the underlying molecular mechanisms during epileptogenesis remain poorly understood. Here we investigated the expression pattern and cellular distribution of ephrinB/EphB in intractable TLE patients and lithium chloride-pilocarpine induced TLE rats using real-time quantitative polymerase chain reaction (RT-qPCR), immunohistochemistry, double-labeled immunofluorescence and Western blot analysis. Compared to control groups, ephrinB3 and EphB3 mRNA expression were significantly up-regulated in intractable TLE patients and TLE rats, while the mRNA expression trend of ephrinB1/2 and EphB1/2/4/6 in intractable TLE patients and TLE rats were inconsistent. Western blot analysis and semi-quantitative immunohistochemistry confirmed that ephrinB3 and EphB3 protein level were up-regulated in intractable TLE patients and TLE rats. At the same time, double-labeled immunofluorescence indicate that ephrinB3 was expressed mainly in the cytoplasm and protrusions of glia and neurons, while EphB3 was expressed mainly in the cytoplasm of neurons. Taken together, up-regulated expression of ephrinB3/EphB3 in intractable TLE patients and experimental TLE rats suggested that ephrinB3/EphB3 might be involved in the pathogenesis of TLE.