Mechanism Of Umbilical Cord Mesenchymal Stem Cells Exosomes Promoting Endothelial Cell Repair Under High Glucose Environment

Background: Endothelial cells are the key cells for wound healing.Stem cell exosomes can promote wound healing.However,how they regulate recipient cells remains to be further studied.Objective:To investigate the healing of umbilical vein endothelial cells by umbilical cord mesenchymal stem cell exosomes under high glucose environment and its related mechanisms.Methods:The endothelial cell injury model with gradient high glucose concentration(5.55,25,40,60,80 m M)was established,and the optimal glucose concentration was selected by CCK8 experiment,nicks experiment,Transwell experiment,tubule formation experiment and other functional experiments.Umbilical cord mesenchymal stem cell exosomes were added into cell injury model,and the biological functions of human umbilical cord mesenchymal stem cell exosomes on high glucose injury cell model were detected by CCK8 assay,Transwell assay and tubule formation assay.A diabetic mice wound model was constructed,and stem cell exosome was injected,and PBS was used as control.The effect of human umbilical cord mesenchymal stem cell exosome on wound healing in vivo was determined by measuring the wound area on skin surface,HE staining,Masson staining and CD31 expression.Finally,transcriptional sequencing was performed in the high glucose cell injury model with exosome intervention to screen the differential m RNA and possible molecular pathways of the receptor cells with high glucose injury regulated by exosome.Results: CCK8 test,scratch test,Transwell test and tubule formation test were used to detect the effects of different glucose concentrations on the function of human umbilical vein endothelial cells.The results showed that the optimal glucose concentration was 60mmol/L for establishing cell injury model.Extractive exosomes of human umbilical cord mesenchymal stem cells were extracted to intervene endothelial cells damaged by high glucose.Results of CCK8,Transwell and tubule formation experiments showed that the proliferation,migration and tubule forming ability of the exosomes group were significantly stronger than that of the control group.Extractive exosomes of human umbilical cord mesenchymal stem cells were extracted to intervene endothelial cells damaged by high glucose.Results of CCK8,Transwell and tubule formation experiments showed that the proliferation,migration and tubule forming ability of the exosomes group were significantly stronger than that of the control group.The wound model of diabetic mice also showed that the wound healing degree of the group with exosome was better than that of the control group.Transcriptional sequencing results of the high glucose cell injury model with exosome intervention revealed509 differentially expressed genes,of which 267 m RNA were upregulated and 242 m RNA were down-regulated in the exosome intervention group.Bioassay results showed that these differentially expressed genes were involved in angiogenesis,lipopolysaccharide response,digestion and absorption,and cytokine-cytokine receptor interactions,respectively,but the specific molecules and pathways need further verification.Conclusion: High glucose can inhibit the proliferation and migration of endothelial cells,and human umbilical cord mesenchymal stem cell exosomes can promote the proliferation and migration of endothelial cells,and also promote the wound healing of diabetic injury model mice.After treating endothelial cells with exosomes from human umbilical cord mesenchymal stem cells,509 differentially expressed genes were found,of which 267 were up-regulated and 242 downregulated.These differential genes are involved in vascular formation,lipopolysaccharide reaction,digestion and absorption,and cytokine-cytokine receptor interaction,and promote endothelial cell healing in high glucose environment.5 figures;79 references in text;67 references in review...