Exosomes from human adipose-derived stem cells promoted the expression of angiogenic factors in endothelial cells

Abstract

Introduction: In regenerative medicine, human adipose tissue–derived mesenchymal stem cells (hadMSCs) have exhibited tremendous promise as an efficient approach to chronic cardiovascular diseases. Noble effects of mesenchymal stem cells (MSCs) have been acknowledged to contribute to not only cellular engraftment and response to the site of injury but also paracrine action via the release of extracellular vesicles, notably exosomes. This study aimed to investigate the effects of exosomes from hadMSCs (hadMSC-Exo) on the angiogenesis of endothelial cells. Methods: Firstly, hadMSCs were characterized and cultured at a density of 500,000 cells in exosome-free medium for 48 hours. The conditioned medium was ultracentrifuged for exosome isolation. Obtained exosomes were characterized with the expression of CD9, CD63, and CD81 markers by flow cytometry and imaged with a TEM microscope. Exosomes were added to a culture medium of human umbilical vein endothelial cells (HUVECs) to understand the effects of exosomes on HUVECs. The expression of some angiogenic genes in HUVECs was identified by RT-qPCR. Results: The concentration of total protein in isolated exosomes by Bradford assay was 0.51 ± 0.04 mg/mL. Exosomes were successfully isolated and characterized by their morphology and immunophenotype. The results showed that exosomes significantly increased the mRNA expression of TGF (11.56 ± 2.03, P < 0.05), Flk-1 (4.04 ± 0.01, P < 0.05), VE-cadherin (7.25 ± 2.30, P < 0.05), and CD31 (3.02 ± 1.13, P < 0.05). Conclusion: This study suggested that exosomes promoted the angiogenesis of endothelial cells in vitro.