Exosomal miR-21 derived from Schwann cells promoting the repair of sciatic nerve injury by targeting SPRY2
Objective:To investigate the effect and potential mechanism of exosomal miR-21 derived from Schwann cell(SC)in the repairment of sciatic nerve injury(SNI).Method:SC was infected with negative control lentivirus and lentivirus that expression of miR-21,and its exosome was collected and identified respectively.The SNI rat model was established by nerve stump anasto-mosis.After surgery,the rats were randomly divided into the model group(n=10),the SC-derived exosome group(n=10)and the SC-derived exosome group(n=10)that high expression of miR-21.The SC-derived exosomes group and SC-derived exosome group that high expression of miR-21 were treated with local injec-tion of exosome collected in vitro.After 3 weeks,the functional recovery was detected by behavioral experi-ment.The nerve regeneration was evaluated by immunofluorescence staining.RT-qPCR was used to detect the expression of miR-21 in serum exosome and miR-21 and SPRY2 in sciatic nerve.The targeting interaction be-tween miR-21 and SPRY2 was verified by dual-luciferase reporter gene experiment.Result:Compared with the model group,the functional recovery and regeneration of sciatic nerve were signifi-cantly improved in the other two groups.The expression of miR-21 was significantly increased,while the ex-pression of SPRY2 was significantly decreased.The improvement in the SC-derived exosome group with high expression of miR-21 were more significantly than those in the SC-derived exosome group.Conclusion:Exosomal miR-21 derived from SC can significantly promote the repair of sciatic nerve injury by targeting SPRY2.