Downregulation of miR-125a-5p Promotes Endothelial Progenitor Cell Migration and Angiogenesis and Alleviates Deep Vein Thrombosis in Mice Via Upregulation of MCL-1.

Endothelial progenitor cells (EPCs) contribute to recanalization of deep vein thrombosis (DVT). MicroRNAs (miRNAs) play regulatory roles in functions of EPCs, which is becoming a promising therapeutic choice for thrombus resolution. The main purpose of this study was to explore the effect of miR-125a-5p on EPC functions in deep vein thrombosis (DVT). EPCs were isolated from the peripheral blood of patients with DVT. In DVT mouse models, DVT was induced by stenosis of the inferior vena cava (IVC). The levels of miR-125a-5p and myeloid cell leukemia sequence 1 (MCL-1) in EPCs and thrombi of DVT mice were detected by RT-qPCR. EPC migration, angiogenesis, and apoptosis were estimated by Transwell assay, tube formation assay, and flow cytometry analysis. Luciferase reporter assay was utilized for detecting the binding of miR-125a-5p and MCL-1. The phosphorylation of PI3K and AKT was estimated by western blot. DVT formation in vivo was observed through hematoxylin-eosin (H&E) staining. The expression of thrombus resolution marker, CD34 molecule (CD34), in the thrombi was measured by immunofluorescence staining. MiR-125a-5p upregulation repressed EPC migration and angiogenesis and facilitated apoptosis. MiR-125a-5p downregulation showed the opposite effect. MCL-1 was targeted and negatively regulated by miR-125a-5p. Additionally, miR-125a-5p inhibited the PI3K/AKT pathway in EPCs. Inhibition of MCL-1 or PI3K/AKT pathway reversed the effect of miR-125a-5p knockdown on EPC functions. The in vivo experiments revealed that miR-125a-5p downregulation repressed thrombus formation and promoted the homing capability of EPCs to the thrombosis site, thereby alleviating DVT mice. Downregulation of miR-125a-5p promotes EPC migration and angiogenesis by upregulating MCL-1, thereby enhancing EPC homing to thrombi and facilitating thrombus resolution.