Illumina deep sequencing reveals conserved and novel microRNAs involved in the response to X-ray irradiation after peripheral nerve injury in rats.

Peripheral nerve injury is a common disease in clinic practice. Low-dose radiation exposure can increase recovery from peripheral nerve injury, but the mechanism is unclear. The objective of this study was to explore the ways that microRNAs participate in the recovery from peripheral nerve injury in rats. To explore the function of miRNAs in this process, we performed Illumina deep sequencing to investigate miRNA expression in spinal cords after X-ray irradiation. Two miRNA libraries (0 GY and 1 GY) were constructed for Illumina sequencing. The sequencing results showed that a total of 53,342,744 raw reads for the control group -0Gy and 48,453,367 raw reads for treated group -1Gy were obtained. After a series of selections, a total of 804 miRNAs were identified. One hundred fifty miRNAs were differentially expressed between the treated group -1Gy and control group -0Gy. A total of 23,652 target genes and 48,157 target sites were predicted for the 150 differentially expressed miRNAs. GO and KEGG enrichment analyses revealed that the PI3K-Akt-signaling pathway, neuroactive ligand-receptor interaction, and the MAPK signaling pathway were enriched. We demonstrated that the novelmiRNAs-360,-301,-239, and -400 targeted Vegfa and regulated its expression after irradiation. Our study revealed that many novel miRNAs were induced by X-ray irradiation, and were involved in the recovery from peripheral nerve injuries. This study provides a framework for understanding the molecular mechanisms underlying the recovery from peripheral nerve injury following exposure to X-ray irradiation.