Integrated analysis of porcine brain microRNA profiles following pediatric diffuse traumatic brain injury

Mild traumatic brain injury (mTBI) is underdiagnosed and can lead to long-term symptoms in children. Currently, we lack diagnostic markers and effective therapies for pediatric mTBI. MicroRNAs (miRNAs) show promise for diagnosing and treating pediatric mTBIs due to their role in regulating key biological processes. Cyclosporine A (CsA) has also shown therapeutic effectiveness in modulating neuronal recovery and protection. We aimed at studying miRNA changes in the frontal lobe (FL) and hippocampus + amygdala (H&A) after a sagittal rapid non-impact head rotation (RNR) in 4 week old piglets (N = 50) at 1 day post-injury, 1 week post-injury, and following 1 day of 20 mg/kg/day Cyclosporine A (CsA) treatment compared to anesthesia-only shams. Interestingly, many miRNAs involved in disrupted neuronal and upregulated glial, epithelial, and endothelial functions were differentially expressed (DE-miRNAs) at 1 day post-injury and most returned to baseline by 1 week post-injury. However, miR-20a-3p, miR-10386, and miR-4331-3p were among the Top 10 DE-miRNAs at 1 day post-injury, and remained altered at 1 week. Upregulated neuroprotective miR-17-3p and miR-212 were also part of the Top 10 DE-miRNAs at 1 day post-injury, and their increases were correlated with decreases in axonal injury. Furthermore, to identify miRNAs that could serve as candidate diagnostic biomarkers of injury, we employed LASSO analysis and identified miRNAs miR-363, miR-15b, and miR-450c-3p as the best predictors of mTBI at 1 day post-injury. Lastly, WGCNA revealed the possible neuroprotective effects of CsA treatment in ameliorating neuronal, immune, stress, and vascular functions disrupted at 1 day post-injury. Overall, our data revealed key miRNAs that were differentially expressed at 1 day and 1 week post-injury, modulated by CsA treatment, and suggest that they may serve as diagnostic biomarkers of pediatric mTBI.