EphrinB/EphB Signaling Regulates Synaptic Plasticity And Contributes To Migraine Chronification

Objective The specific mechanism of migraine chronification remains unclear.At present,central sensitization is mainly considered as a major pathophysiological mechanism of chronic migraine,and central sensitization is manifested by increased neuronal excitability and changes in synaptic plasticity.Our previous studies also showed changes in synaptic plasticity during the chronification of migraine.The Eph B receptors and its ligands,members of the receptor tyrosine kinase family,have been shown to be crucial for the regulation of synaptic plasticity in the central nervous system.Therefore,this study aims to explore whether ephrinB/EphB signaling can regulate synaptic plasticity and thus contribute to the migraine chronification.Methods1.The rat CM model was established by repeated dural infusion of inflammatory soup(IS)and was evaluated;then the expression and distribution of Eph B2 and ephrin B2 in the trigeminal spinal nucleus(TNC)were detected by q PCR,WB and immunofluorescence;after the inhibitor of Eph B receptor(Eph B1-Fc)was administered to the lateral ventricle,the paw withdrawal threshold(PWT)and paw withdrawal latency(PWL)of the rats were detected to evaluate the role of ephrinB/EphB signaling in CM.2.After Eph B1-Fc was administered to the lateral ventricle,the expression of three synapse-associated proteins was detected by WB,the changes of dendritic spines of neurons were observed by Golgi-cox staining,and the ultrastructure of synapses was observed by transmission electron microscopy to explore the effect of ephrinB/EphB signaling on synaptic plasticity of CM.At the same time,after injection of Eph B1-Fc in lateral ventricle,the changes of two related indicators of central sensitization(SP and c-Fos)and the expression of NR2 B,p NR2 B,Ca MKII,CREB,p CREB in TNC were detected by WB to study the mechanism of ephrinB/EphB signaling in chronic migraine.Results1.PWT and PWL were significantly reduced and the expression of CGRP in the TNC was increased after the dural infusion of IS,which indicating that the CM model was successfully constructed.The m RNA and protein expression of Eph B2 and ephrin B2 in the CM group were significantly higher than those in the sham group,indicating that there may be activation of Eph B2 and ephrin B2 in CM.The inhibitor of Eph B receptor alleviated the decrease in PWT and PWL and prevented the expression of CGRP,indicating that ephrinB/EphB signaling play an important role in CM.2.Eph B1-Fc significantly prevented the change of synaptic plasticity in CM,and inhibited the increase of SP fluorescence intensity and the increase of c-Fos expression in CM group,indicating that ephrinB/EphB signaling may lead to central sensitization by regulating synaptic plasticity.In addition,WB results showed that injection of Eph B1-Fc in the lateral ventricle reduced the expression of p NR2 B,Ca MKII,and p CREB in CM rats,indicating that the regulation of ephrinB/EphB signaling in the chronification of migraine may involve NR2 B phosphorylation and the Ca MKII/CREB pathway.Conclusion The above results indicate that there may be activation of Eph B2 and ephrin B2 during the chronification of migraine.Inhibition of Eph B receptors can relieve changes in synaptic plasticity of CM and changes in central sensitization-related indicators.This indicates that ephrinB/EphB signaling may participate in central sensitization by regulating synaptic plasticity,and then lead to the chronification of migraine.Therefore,blocking the ephrinB/EphB signaling may prevent the development of chronic migraine.