〔Abstract〕 Objective To investigate the effect of exosomes secreted by glioma stem cells(GSCs) on human-derived brain microvascular endothelial cells(HBMECs) with hypoxia/reoxygenation injury. Methods Human glioma U87 cell line tumor stem cells were cultured in vitro, and the successfully cultured tumor cell spheres were routinely identified by immunohistochemical staining and differentiation. The QIAGEN kit was used to extract exosomes from stem cell culture medium. HBMECs were randomly divided into 3 groups: ① normal control group(CON): 1640 cell culture medium containing 10% exosome-depleted FBS, conventional human brain microvascular endothelium cell culture; ② hypoxia/reoxygenation group(H/R): vascular endothelial cells were given hypoxia for 5 h, and then reoxygenated for 1 h; ③ exosomes pretreated group secreted by stem cells(GSCs-Exo+H/R): HBMECs were incubated with 60 μg/ml of GSCs-Exo prior to H/R treatment. At the end of the treatment, the prolif-eration viability,the migration ability and the apoptosis of the three groups were detected. Results Immunofluorescence staining demonstrated that Nestin and CD133 were specifically expressed in cultured glioma stem cells. Positive expression of GFAP and Neun was observed in differentiation of tumor cells. Compared with the CON group,the proliferation and migration of vascular endothelial cells in the H/R group significantly decreased,and the apoptosis rate significantly increased( P<0. 05). Compared with the H/R group,GSCs-Exo co-incubation with vascular endothelial cells could significantly increase the proliferation of endothelial cells,promote cell migration and inhibit vascular endothelial cell apoptosis( P<0. 05). Conclusion In the hypoxic/reoxygenation microenvironment of glioma,exosomes secreted by glioma stem cells can protect vascular endothelial cells.