Objective:To investigate the effects of mesenchymal stem cells-derived exosomes (MSC-Exos) secreted by mesenchymal stem cells (MSCs) induced by astragaloside IV (AS-IV) on the biological function and pyroptosis of human umbilical vein endothelial cells (HUVECs) injured by high glucose.Methods:After human umbilical cord blood mesenchymal stem cells (hUCBMSCs) were intervened with 400 mg/L of AS-IV, exosomes were extracted, and then the morphology and specific markers of exosomes were identified. Human umbilical vein endothelial cells (HUVECs) were cultured in a medium with a glucose concentration of 30 mmol/L to prepare a high glucose-impaired HUVECs model. High glucose-impaired HUVECs were randomly divided into experimental and model groups, with the experimental group intervened with 100 μg/ml of MSC-Exos and the model group intervened with an equal volume of PBS solution, while a blank control group was also set up. Cell counting Kit-8 (CCK-8) cell proliferation assay, adhesion assay, matrigel tube formation assay and scratch assay were used to detect the effects of AS-IV-mediated MSC-Exos on the proliferation, adhesion, tube formation and migrationability of HUVECs; Western blot and real time fluorescence quantitative polymerase chain reaction (qRT-PCR) were used to detect the protein and mRNA expression of scorch death-related molecules, such as Caspase-1, GSDMD (Gasdermin D) and NLRP3 in each group.Results:The proliferation, adhesion number, tube number and migration width of HUVECs cells were significantly lower than those in the blank group ( P<0.05); The expression of Caspase-1, GSDMD, NLRP3 protein and their mRNA increased significantly ( P<0.001); Under the intervention of MSC-Exos mediated by AS-IV, the cell proliferation, adhesion number, tube number and migration width of HUVECs were significantly higher than those in the model group ( P<0.05); The expression of Caspase-1, GSDMD, NLRP3 protein and their mRNA decreased, with statistically significant difference ( P<0.05). Conclusions:AS-IV mediated MSC-Exos can significantly improve the biological function of high glucose-impaired endothelial cells, and its mechanism may be related to anti-pyroptosis.

Objective:To investigate the effect of Astragaloside Ⅳ-mediated Endothelial progenitor cells derived exosomes (EPC-Exos) on the biological function of EPC-Exos damaged by high glicose.Methods:EPCs from human umbilical cord blood were isolated and cultured in vitro. the EPC-Exos secreted by EPCs were extracted by ultracentrifugation combined with ultrafiltration, and identified by specific markers CD9, CD63 and CD81, respectively. After the cells were cultured for 24 hours with AS-IV at 100 mg/L and PBS at the same volume, the morphological characteristics of EPC-Exos were observed by transmission electron microscope. Human endothelial cells were isolated, cultured and identified in vitro. The identified endothelial cells were pretreated with 30 mmol/L glucose for 120 h and randomly divided into experimental group and control group, at the same time set the normal group. The cells were cultured for 24 hours, the effects of EPC-Exos on proliferation, adhesion, migration and angiogenesis of endothelial cells damaged by high glucose were observed by using cell counting kit-8 (CCK-8) Cell Proliferation Assay Kit, cell scratch test, adhesion assay and in vitro angiogenesis assay by Matrigel. Results:Compared with the normal group, the proliferation, migration, adhesion and tubulogenesis of human endothelial cells in the control group were significantly lower ( t=24.35, 6.80, 10.65, 9.62, P<0.05). Compared with the control group, the proliferation, adhesion, migration and tubulogenesis of human endothelial cells in the experimental group were significantly enhanced ( t=30.68, 5.99, 5.40, 8.25, P<0.05). Conclusions:EPC-Exos mediated by AS-Ⅳ can significantly improve the biological function of human endothelial cells damaged by high glucose and has the potential to modulate endothelial neovascularization in diabetic rats.