摘要：

We have previously demonstrated the cardioprotective effects of exosomes derived from mesenchymal stem cells (MSCs). It is well known that the activation of Akt is involved in stem cell‐induced cardioprotection. In the present study, we investigated whether exosomes released fromAkt‐overexpressing MSCs showed a beneficial effect on cardioprotection and angiogenesis. MSCs were collected from human umbilical cord (hucMSCs), andAktwas transfected into hucMSCs (Akt‐hucMSCs) by using an adenovirus transfection system. Exosomes were isolated from control hucMSCs (Exo) and Akt‐hucMSCs (Akt‐Exo). An acute myocardial infarction model was created by ligation of the left anterior decedent coronary artery (LAD) in rats. Various source exosomes (400 µg of protein) were infused via the tail vein immediately after LAD ligation. The cardiac function was evaluated by using echocardiography after different treatments for 1 and 5 weeks, respectively. Endothelial cell proliferation, migration, and tube‐like structure formation, as well as chick allantoic membrane assay, were used to evaluate the angiogenetic effects of Akt‐Exo. The results indicated that cardiac function was significantly improved in the animals treated with Akt‐Exo. In addition, Akt‐Exo significantly accelerated endothelial cell proliferation and migration, tube‐like structure formation in vitro, and blood vessel formation in vivo. The expression of platelet‐derived growth factor D (PDGF‐D) was significantly upregulated in Akt‐Exo. However, the angiogenesis was abrogated in endothelial cells treated with the exosomes obtained from MSCs transfected with PDGF‐D‐siRNA. Our studies suggest that exosomes obtained fromAkt‐modified hucMSCs are more effective in myocardial infarction therapy through promoting angiogenesis. PDGF‐D plays an important role in Akt‐Exo‐mediated angiogenesis. StemCellsTranslationalMedicine2017;6:51–59

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