Dysregulation of miR-301a-3p serves as a non-invasive biomarker and is associated with inflammatory responses in traumatic spinal cord injury.

Background: Spinal cord injury (SCI) led by trauma is a serious damage in central nervous system. This study aimed at confirming the expression levels and clinical significance of miRNA-301a-3p (miR-301a-3p) in SCI patients, and exploring the potential mechanisms of miR-301a-3p participating in SCI progression.
Methods: One hundred and thirty nine acute spinal trauma patients, included neurologically normal, incomplete and complete SCI cases, were analyzed in this study. Quantitative real-time PCR was used to measure the expression of miR-301a-3p. Receiver operating characteristic (ROC) was used to evaluate the diagnostic accuracy of serum miR-301a-3p in SCI. LPS-treated SH-SY5Y cells were used to mimic SCI inflammatory injury. The levels of IL-1β, IL-6, TNF-α were detected using enzyme-linked immunosorbent assay.
Results: Expression of serum miR-301a-3p was significantly higher in both incomplete and complete SCI patients than that in neurologically normal controls, and had a significant ability to distinguish SCI patients from controls. Additionally, complete SCI cases had markedly increased miR-301a-3p compared to incomplete cases, and the two groups of patients could be distinguished based on serum deregulated miR-301a-3p. In the SCI cell model, miR-301a-3p overexpression led to decreased cell viability. The inflammatory responses of the cell model were enhanced by miR-301a-3p, which was consistent with the findings in SCI patients that serum miR-301a-3p was positively correlated with pro-inflammatory cytokines.
Conclusion: The expression of miR-301a-3p is increased in SCI patients, and serves as a candidate biomarker for SCI diagnosis. MiR-301a-3p may be involved in SCI progression by affecting neuronal viability and inflammation.