Astragaloside IV drug-loaded exosomes (AS-IV EXOs) derived from endothelial progenitor cells improve the viability and tube formation in high-glucose impaired human endothelial cells by promoting miR-214 expression

The high glucose changes caused by diabetes mellitus (DM) can damage the vascular system. Astragaloside IV (AS-IV) can improve diabetes and promote angiogenesis. Exosomes (EXOs) help to carry specific drugs into cells efficiently. However, whether AS-IV loaded EXOs (AS-IV EXOs) can improve damaged endothelial cells through miR-214 remains to be determined. We prepared and identified AS-IV EXOs derived from endothelial progenitor cells (EPCs) and high glucose stimulated endothelial cell models to investigate whether AS-IV EXOs can improve damaged endothelial cells through miR-214. We used a transmission electron microscope (TEM) and DAPI staining to identify the morphology and characteristic expression of EPCs and EXOs, and then prepared AS-IV EXOs. Cell function tests were performed to detect the cloning, proliferation, and migration capabilities of cells. Western blot (WB) and real-time quantitative polymerase chain reaction (qRT-PCR) were used to assess the expression level of Tie-2, Ang-1, and PI3K/Akt-related protein. The DAPI staining results showed that inducing human umbilical vein endothelial cells (HUVECs) could effectively absorb AS-IV EXOs. The results of plate clone formation assay, CCK-8, cell adhesion, and transwell assay of HUVECs stimulated by high glucose showed that AS-IV EXOs had a damage relief effect. By the detection of WB and qRT-PCR, it was found that AS-IV EXOs promoted the expression of miR-214 and proteins related to blood vessel growth. After transfection of miR-214 to pre-treat HUVECs under high glucose stimulation, AS-IV EXOs promoted the tube formation of HUVECs by regulating the level of miR-214. By promoting the expression of miR-214, AS-IV EXOs significantly improved the activity and tubularization of HUVECs under high glucose stimulation.