PDGFB and diabetes mellitus: Thus, downregulation of miR-139-5p expression in ECFCs promotes activation of c-jun, VEGF, and PDGF-B signaling (Figure 11C), indicating that miR-139-5p is required for c-jun activation in diabetes, which is at least partly related to a reduction in VEGF and PDGF-B response in diabetic ECFCs.