The regulatory effect of miR-221/222 on endothelial differentiation of adipose-derived stem cells

Abstract Objective Adipose-derived stem cells (ADSCs) are a kind of adult mesenchymal stem cell, which show a repair effect in ischemic tissues due to its capacity of endothelial differentiation. MicroRNA‑221/222 (miR‑221/222) has been extensively studied in endothelial cells (ECs). However, the mechanism that regulates ADSCs differentiation toward ECs is unknown. In this work, we investigated the effects of miR-221/222-overexpressing/silence in ADSCs on endothelial differentiation by construction of lentiviral vectors. Methods The differentiative capacity was assessed by measuring the expression of endothelial markers (CD31, CD34, CD144 and eNOS). Meanwhile, the low-density lipoprotein (LDL) uptake and tube-like formation were performed for evaluation of functional characterization. In order to clarify the function mechanism of this gene, the PI3K/AKT signaling pathway was investigated by western blotting. The revascularization of miR-221/222-transfeted ADSCs were further verified in vivo experiment. Results The results confirmed that transfection with miR-221/222 gene promoted the expression of endothelial markers, LDL uptake and tube-like formation. As expected, the PI3K/AKT signaling pathway was effectively activated during the endothelial differentiation of ADSCs when miR-221/222 genes were highly expressed. Furthermore, injection of miR-221/222 transfected ADSCs could significantly improve rat hindlimb ischemia evidenced by increase in blood flow and structural integrity, and reduce in inflammatory infiltration. Conclusion The results of the present study suggested that miR-221/222 is essential for endothelial differentiation in ADSCs, providing a novel strategy for modulating vascular formation and ischemic tissue regeneration.