Huang Hao, Li Ruohan, Yuan Jinxian, Zhou Xin, Liu Xi, Ou Shu, Xu Tao, Chen Yangmei
Department of Neurology, Second Affiliated Hospital of Chongqing Medical University, 74 Lin Jiang Road, Chongqing 400010, China.
Department of Neurology, Second Affiliated Hospital of Chongqing Medical University, 74 Lin Jiang Road, Chongqing 400010, China.
Brain Res. 2016 May 15;1639:1-12. doi: 10.1016/j.brainres.2016.02.035. Epub 2016 Feb 27.
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.
EphB家族受体酪氨酸激酶与细胞表面结合的ephrinB配体协同作用，在维持中枢神经系统（CNS）的树突棘形态发生、轴突导向、突触发生、突触重组和可塑性方面发挥关键作用。然而，ephrinB/EphB在难治性颞叶癫痫（TLE）中的表达模式以及癫痫发生过程中的潜在分子机制仍知之甚少。在此，我们使用实时定量聚合酶链反应（RT-qPCR）、免疫组织化学、双标免疫荧光和蛋白质印迹分析，研究了难治性TLE患者以及氯化锂-匹罗卡品诱导的TLE大鼠中ephrinB/EphB的表达模式和细胞分布。与对照组相比，难治性TLE患者和TLE大鼠中ephrinB3和EphB3 mRNA表达显著上调，而难治性TLE患者和TLE大鼠中ephrinB1/2和EphB1/2/4/6的mRNA表达趋势不一致。蛋白质印迹分析和半定量免疫组织化学证实，难治性TLE患者和TLE大鼠中ephrinB3和EphB3蛋白水平上调。同时，双标免疫荧光表明，ephrinB3主要表达于神经胶质细胞和神经元的细胞质及突起中，而EphB3主要表达于神经元的细胞质中。综上所述，难治性TLE患者和实验性TLE大鼠中ephrinB3/EphB3表达上调表明ephrinB3/EphB3可能参与TLE的发病机制。
