AUTHOR=Qi Zheng , Zhao Yingying , Su Yu , Cao Bin , Yang Jian-Jun , Xing Qinghe 

TITLE=Serum Extracellular Vesicle–Derived miR-124-3p as a Diagnostic and Predictive Marker for Early-Stage Acute Ischemic Stroke

JOURNAL=Frontiers in Molecular Biosciences

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2021.685088

DOI=10.3389/fmolb.2021.685088

ISSN=2296-889X

ABSTRACT=<p><bold>Background:</bold> A delay in the diagnosis of acute ischemic stroke (AIS) reduces the eligibility and outcome of patients for thrombolytic therapy. Therefore, early diagnosis and treatment of AIS are crucial. The present study evaluated the sensitivity and accuracy of serum extracellular vesicle (EV)-derived <italic>miR-124-3p</italic> in the diagnosis and prediction of AIS.</p><p><bold>Methods:</bold> An miRNA expression profile was downloaded from Gene Expression Omnibus (GEO) database and analyzed by R software. EVs were harvested from the serum of AIS patients using a total exosome isolation kit and characterized by Western blotting, a transmission electron microscope, and the nanoparticle tracking analysis. BV2 microglia were pre-stimulated with lipopolysaccharide (LPS), followed by <italic>miR-124-3p</italic> treatment for 24 h and subsequent analysis of viability, apoptosis, and migration (scratch assay), and Western blotting. The relative expression of the selected genes was assessed by qRT-PCR. The phosphorylation of Erk1/2, PI3K/Akt, and p38MAPK in BV2 microglia cells was evaluated by Western blotting, while the luciferase reporter gene assay detected the correlation between key genes involved in the pro-inflammatory signaling pathways and <italic>miR-124-3p</italic>.</p><p><bold>Results:</bold><italic>hsa-miR-124-3p</italic> was downregulated in AIS serum compared to the non-AIS serum (<italic>p</italic> &lt; 0.05), and the gene expression of <italic>has-miR-124-3p</italic> in EVs was negatively correlated with serum pro-inflammatory cytokines and the NIHSS (<italic>p</italic> &lt; 0.05). In addition, <italic>miR-124-3p</italic> promoted the viability and inhibited the apoptosis of LPS-induced BV2 microglia. Furthermore, <italic>miR-124-3p</italic> reduced the phosphorylation of Erk1/2, PI3K/Akt, and p38MAPK, and promoted the migration in LPS-induced BV2 microglia (<italic>p</italic> &lt; 0.05).</p><p><bold>Conclusion:</bold> Serum EV-derived <italic>miR-124-3p</italic> serves as a diagnostic and predictive marker for early-stage AIS.</p>