Serum miR-192-5p is a promising biomarker for lethal radiation injury.

In the event of a nuclear or radiation accident, rapid identification is required for those who exposed to potentially lethal dose irradiation. However, existing techniques are not adequate for the classification of lethal injury. Several studies have explored the potential of miRNAs as biomarkers for ionizing radiation injury, however, there are few miRNAs with specific expression for lethal radiation injury. Therefore, the aim of this study was to screen and validate the possibility of serum miRNAs as biomarkers of lethal radiation injury. We found the specific expression of mmu-miR-374c-5p / mmu-miR-194-5p on first day and mmu-miR-192-5p / mmu-miR-223-3p on third day in the mouse serum only under 10 Gy irradiation by miRNA sequencing and all significantly correlated with lymphocyte counts by Pearson's correlation analysis. In addition, it was found that among the 4 candidate serum miRNAs, only highly-expressed mmu-miR-192-5p in mouse serum irradiated at lethal doses was returned to sham-like expression levels at 3 days post-irradiation with amifostine pretreatment and closely correlated with survival rate. We demonstrated for the first time that mmu-miR-192-5p screened from lethally irradiated mice sera can be used as a potential biomarker for lethal irradiation injury, which will be helpful to improve efficiency of medical treatment to minimize casualties after a large-scale nuclear accident.