Down-regulation of miR-361-5p promotes the viability, migration and tube formation of endothelial progenitor cells via targeting FGF1.

Transplantion of bone marrow-derived endothelial progenitor cells (EPCs) may be a novel treatment for deep venous thrombosis (DVT). The present study probed into the role of microRNA (miR)-361-5p in EPCs and DVT recanalization. EPCs were isolated from male Sprague-Dawley (SD) rats and identified using confocal microscopy and flow cytometry. The viability, migration and tube formation of EPCs were examined using MTT assay, wound-healing assay and tube formation assay, respectively. Target gene and potential binding sites between miR-361-5p and fibroblast growth factor 1 (FGF1) were predicted by StarBase and confirmed by dual-luciferase reporter assay. Relative expressions of miR-361-5p and FGF1 were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot as needed. A DVT model in SD rats was established to investigate the role of EPC with miR-361-5p antagomir in DVT by Hematoxylin-Eosin (H&E) staining. EPC was identified as 87.1% positive for cluster of difference (CD)31, 2.17% positive for CD133, 85.6% positive for von Willebrand factor (vWF) and 94.8% positive for vascular endothelial growth factor receptor-2 (VEGFR2). MiR-361-5p antagomir promoted proliferation, migration and tube formation of EPCs and up-regulated FGF1 expression, thereby dissolving thrombus in the vein of DVT rats. FGF1 was the target of miR-361-5p, and overexpressed FGF1 reversed the effects of up-regulating miR-361-5p on suppressing EPCs. Down-regulation of miR-361-5p enhanced thrombus resolution in vivo and promoted EPC viability, migration and angiogenesis in vitro through targeting FGF1. Therefore, miR-361-5p may be a potential therapeutic target for DVT recanalization.