Dynamic change and significance of miR-124 in vitro after mechanical damage of cortical neurons in mice

SU Xinhong; YE Yuqin; YANG Yongxiang; HE Xiaosheng

Abstract：Objective The changes of microRNA-124 (miR-124) in vitro after mechanical damage of cortical neurons,and the influence of miR-124 on axon regeneration and repair after traumatic brain injury in mice were explored.Methods Primary cortical neurons were obtained from fetal C57BL/6 mice and cultivated for 7 d.Petri dishes were manually scratched with a 10 μL plastic stylet needle following a 9 ×9 square grim.Cells were collected at 1 h,6 h,12 h,24 h,72 h and 144 h after injury for experiments.The real-time polymerase chain reaction (RT-PCR) and Western Blot were used to test the relative expressions of miR-124 and Neuropilin-1 (Nrp-1),microtubuleassociated protein tau (Tau),growth associated protein 43 (Gap-43),respectively.Then miR-124 mimic and inhibitor were used to intervene the cortex neuron in vitro to observe how the change of miR-124 expression quantity affected the experiment.Results MiR-124,Nrp-1,Tau and Gap-43 were significantly increased after mechanical damage of cortical neurons (P ＜0.05) and there was a positive correlation between them.The miR-124 mimic and inhibitor were significandy increased and decreased the expression of miR-124 respectively and then caused a significant reduction in the expressions of Nrp-1,Tau,Gap-43 and the decrease in inhibitor group was more significant than that of mimic group (P ＜0.05).Conclusion Moderate high expression of miR-124 may be closely related to the axon regeneration.The result provides the experimental basis for regulating the expression of miR-124 gradually to regulate neural axon regeneration and restoration.