The Research For Exosomes Derived From Mouse Islet Endothelial Cells Under The Condition Of Oxidative Stress To Protect Against Oxidative Stress

Background:The incidence and prevalence of diabetes increases year by year and becomes a significant social problem that threatens people’s health. The oxidative injury of β cells and functional impediment are main reasons why diabetes occurs.However,with full of vascularization, increasing evidence suggest that the oxidative injury of islet microvascular endothelial cells (IMECs) plays a significant part in etiology of diabetes mellitus.Exosomes are40-100nm diameter membranous vesicles of endocytic origin that are released by a variety of cell types into the extracellular space.As intercellular signalosomes,exosomes play an important role in multiple pathophysiology.In this study,exosomes will act as a bridge communicating IMECs to IMECs, exploring the role what exosome-derived from IMECs under the condition of oxidative stress plays for the same cells.Objective:To set up theoretical basis for restoring the integrity of islet microcirculation,we studied whether the exosomes isolated from mouse islet endothelial cell line (MS-1) under the condition of oxidative stress have the effect on a resistance against oxidative stress of the same cells in vitro.Methods:Exosomes were isolated from MS-1cells with or without hydrogen peroxide (H2O2) stimulation(O-exo and N-exo) with ultracentrifuge, followed by purification and identification. MS-1cells, damaged by the same oxidative environment were at different concentrations in the presence or absence of these exosomes (0,5,10,50,100μg/mL). CCK-8and AnnexinV-PI double staining were used to distinguish the cell viability among groups.In addition, we studied the level of apoptosis related gene Caspase-3and Bcl-2mRNA expression with real-time PCR analysis.Results:O-exo were lower than N-exo in quality(The former number was0.3ug per106cells, the latter was0.6ug per106cells, P<0.05).When tested at50μg/mL, exosomes extracted from MS-1cells induced by H2O2significantly prevented oxidant-enticed apoptosis of MS-1cells relative to control group, with apoptosis ratio decreased by6.1%(P<0.05)and OD value increased ((P<0.01). Hours of exposure, there was an obvious decrease of Caspase-3and increase of Bcl-2(at mRNA level) in O-exo-treated MS-1cells compared to control cultured cells (P<0.05).Conclusion:There is difference between O-exo and N-exo in quality and quantity.MS-1cells deliver protective messages under the condition of oxidative stress to improve the same cells survival against detrimental factor in vitro and therefore provide a new approach for the repairment of islet microcirculation in type2diabetes.