Mechanism of hyperglycemia-mediated downregulation of miR-24. (A) Western blot analysis of VWF and c-Myc expression in cell lysates under conditions of normal or high glucose (72-hour cultured HUVECs) in the presence or absence of an aldose reductase inhibitor (epalrestat). (B) qPCR quantitation of miR-24 expression in normal or high glucose (72-hour cultured HUVECs) with or without aldose reductase inhibitor (epalrestat); **P < .01; *P < .05. (C) Time course analysis of c-Myc mRNA expression in normal or high glucose (cultured HUVECs) using qPCR quantitation (normalized to GAPDH). (D) Endothelial cells were incubated with different concentrations of H₂O₂ (0 to 2000 μM) for 1 hour prior to analysis of cell lysates with western blot. (E) Western blot analysis of endothelial cell lysates when transfected with si-cMyc or si-Control followed by qPCR quantitation of miR-23/24/27 clusters expression; ***P < .001; **P < .01. (F) Western blot analysis of endothelial cell lysates when transfected with si-cMyc or si-Control followed by qPCR quantitation of miR-24/335/503 expression; ***P < .001; **P < .01.