Objective To investigate the protective effects and mechanism of microRNA-132 (miRNA-132)- loaded exosomes derived from mesenchymal stem cells on human umbilical vein endothelial cells (HUVECs) under hypoxic condition.Methods Electroporation method was applied to transfect miRNA-132 negative control (NC) and miRNA-132 mimics into mesenchymal stem cell-derived exosomes as control exosomes (Exo) and miRNA-132 loaded exosomes (miRNA-132 Exo), respectively. Equal amount of phosphate buffered saline (PBS), Exo and miRNA-132 Exo were co-cultured with HUVECs for 48 h in a hypoxia incubator. Cell counting kit 8 (CCK-8) was used to detect the cell proliferative ability, tube formation assay was performed to measure the angiogenic ability, and Transwell migration assay was employed to investigate the cell migration ability. In addition, the downstream target genes of miRNA-132 were predicted by TargetScan database, and confirmed by dual-luciferase reporter gene assay, quantitative polymerase chain reaction (qPCR) and Western blotting.Results miRNA-132 mimics were successfully transfected into exosomes by electroporation method. After cultured under hypoxia for 48 h, the proliferative ability, angiogenic ability and migratory ability of HUVECs in the Exo and miRNA-132 Exo groups were significantly higher than those in the PBS group (all P＜0.05), and those in the miRNA-132 Exo group were signficantly higher than those in the Exo group (all P＜0.01). TargetScan database analysis result showed that Ras p21 protein activator 1 (RASA1) may be a target of miRNA-132, which was related to the process of angiogenesis. Dual-luciferase reporter gene assay confirmed that RASA1 was the downstream target of miRNA-132. The results of qPCR and Western blotting showed that treatment with miRNA-132 Exo under hypoxia could inhibit the expression of RASA1 in HUVECs.Conclusion Mesenchymal stem cell-derived exosomes with or without miRNA-132 load could both preserve the proliferative ability, angiogenic ability and migratory ability of HUVECs under hypoxia. miRNA-132 may enhance this protective effect by inhibiting the expression of RASA1.