The role of lncRNA-MEG/miR-21-5p/PDCD4 axis in spinal cord injury

Spinal cord injury (SCI) is an insult to the spinal cord resulting in a change, either temporary or permanent, in its normal motor or sensory function, but the mechanism of neuron loss after spinal cord injury is still unclear. Long non-coding RNAs (lncRNAs) can play an important role in regulating cell physiological activities through competitively binding to miRNAs. However, there is still a lack of research on the effect of lncRNAs on SCI. In this study, we selected SCI gene expression data and miRNA expression data from the NCBI database for differential expression analysis, and predicted miRNA target genes. Subsequently, biological analysis of gene expression and miRNA changes was performed on a rat SCI model. The results showed that the expression level of lncRNA-MEG increased significantly in rat SCI model. Subsequently, we found that lncRNA-MEG can promote the expression level of PDCD4 by inhibiting miR-21-5p, which leads to neuronal cell apoptosis. Furthermore, knocking down of lncRNA-MEG with shRNA can reverse the effect of miR-21-5p and inhibit the effect of PDCD4 to reduce the expression of apoptosis-related proteins. Furthermore, we found lncRNA-MEG can regulate PDCD4 expression through miR-21-5p by targeting 3'UTR of PDCD4 in the OGD cell model. In summary, we first discovered lncRNA-MEG regulates neuronal cell apoptosis through miR-21-5p by targeting PDCD4 in SCI.