The expression level of angiogenesis-related molecules in human umbilical vein endothelial cells (HUVECs) increased after culturing with iMSCs-Exo. Quantitative reverse-transcriptase polymerase chain reaction analysis of the expression level of angiogenesis-related genes (A) and proteins (B) after culturing for 24 and 48 hours. (A) Compared with the control group, iMSCs-Exo upregulated angiogenesis-related gene expression in a dose-dependent manner (*P <0.05) at 24 hours (i) and 48 hours (ii). (B) Compared with the control group, vascular endothelial growth factor (VEGF) (i), transforming growth factor beta 1 (TGFB1) (ii), and Angiogenin (iii) secreted by HUVECs significantly increased after culture with iMSCs-Exo (*P <0.05). angio, Angiogenin; BFGF, basic fibroblast growth factor; BFGFR, basic fibroblast growth factor receptor; HIF-1α, hypoxia-inducible factor-1α; iMSCs-Exo, exosomes derived from induced pluripotent stem cell-derived mesenchymal stem cells; KDR, kinase insert domain receptor; LSGS, low serum growth supplement; M200, Medium 200; PGF, placental growth factor.