An integrative clinical and bioinformatic analysis identifies MicroRNAs as biomarkers of ischemic stroke severity

Identifying reliable circulating biomarkers is crucial for improving the diagnosis and risk stratification of patients with ischemic stroke. In this study, we evaluated several whole-blood circulating miRNAs (miR-106b-5p, miR-16-5p, miR-15b-5p, let-7e-5p, and miR-125a-3p/-5p) to determine their diagnostic and disease severity in acute ischemic stroke (AIS). Sixty AIS patients and thirty age- and sex-matched controls were included. Whole-blood miRNAs were quantified at admission and on day 7. Statistical analyses included ROC curves, multivariate logistic regression, and SHAP-based machine learning. Bioinformatic analyses assessed predicted miRNA targets, pathway enrichment, and interaction networks. MiR-125a-3p was significantly reduced in AIS at both time points, while miR-125a-5p was elevated at admission and decreased by day 7. Both miRNAs showed moderate diagnostic value (AUC 0.675 and 0.712, respectively). Higher admission levels of miR-16-5p were strongly associated with greater neurological deficit (NIHSS) and unfavorable outcome (mRS ≥ 3). Multivariate analyses confirmed high miR-16-5p and elevated CRP as independent predictors of poor outcome. Bioinformatic analyses revealed that miR-16-5p targets were enriched in pathways relevant to ischemic injury, including hypoxia response, platelet activation, coagulation, TGF-β and BDNF signaling. A target-interaction network highlighted IL6, FN1, TGFB1, ICAM1, and TLR4 as central nodes linking miR-16-5p to ischemia-inflammatory mechanisms in AIS. Circulating miRNAs display distinct expression patterns in the acute phase of AIS. miR-16-5p emerges as a promising biomarker associated with stroke severity and unfavorable outcome, while miR-125a-3p and miR-125a-5p show potential diagnostic utility. These findings strengthen mechanistic links between platelet-derived miRNAs and ischemic stroke biology. Larger, longitudinal studies integrating functional validation are warranted to confirm their clinical value.