MiR-139-5p alleviates neural cell apoptosis induced by spinal cord injury through targeting TRAF3

Spinal cord injury (SCI) is a neurological trauma that causes loss of locomotor function and sensory deficit. Previous studies showed that miRNAs play a crucial role in SCI. This study further evaluated the potential role of miR-139-5p in the neural cell apoptosis after SCI in rats. A rat SCI model was successfully established and miR-139-5p expression level in SCI rats was down-regulated compared to the sham group (sham operation group) determined by qRT-PCR. MiR-139-5p overexpression via administration with miR-139-5p agomir improved locomotor functional recovery, attenuated allodynia and hyperalgesia and alleviated neural cell apoptosis in SCI rats. In addition, TRAF3 (TNF receptor-associated factor 3 ) was identified to be a target of miR-139-5p by searching the proposed target genes in TargetScan 7.1 database. Co-transfection of miR-139-5p agomir and adenovirus of TRAF3 plasmids significantly improved functional recovery and alleviated neural cell apoptosis. Therefore, TRAF3 mediated the anti-apoptosis effect of miR-139-5p in SCI rats and miR-139-5p could be a promising candidate for SCI therapy by alleviating neural cell apoptosis through targeting TRAF3.