Exosomes derived from cerebral vascular endothelial cells after ischemic preconditioning protect neurons against oxygen-glucose deprivation-induced injury / 国际脑血管病杂志

ABSTRACT

Objective:To investigate the effect of exosomes (Exo) secreted by brain vascular endothelial cell bEnd.3 after ischemic preconditioning (IPC) on neurons suffering from oxygen and glucose deprivation (OGD).Methods:bEnd.3 was exposed to OGD for 3 h to simulate IPC in vivo. After 48 h of reoxygenation, the Exo (IPC Exo) in the conditioned medium were extracted and identified by Western blot and transmission electron microscopy. IPC Exo were incubated with primary cultured mouse cortical neurons for 24 h. Confocal microscope was used to observe whether Exo could be uptaked by primary cultured mouse cerebral cortical neurons. The primary cultured cortical neurons were divided into control group, OGD group, OGD+ IPC Exo (5 μg/ml, 10 μg/ml, 20 μg/ml) groups and sham OGD group (treated with Exo secreted by bEnd.3 cultured under normoxia conditions). The cell viability was detected by CCK-8 and cell survival/death detection kit.Results:Transmission electron microscopy showed that the extract of bend.3 culture medium showed typical morphology of Exo, i. e., a double concave disc-shaped vesicle with a diameter of 30-100 nm. Western blot analysis showed that the extract of bEnd.3 medium highly expressed Exo markers Alix and Tsg101. Confocal microscopy showed that Exo could be uptaked by primary cultured mouse cortical neurons, and the uptake of Exo was widely distributed in the cytoplasm and synapses. Compared with the OGD group, the addition of 10 and 20 μg/ml IPC Exo could significantly increased the neuronal viability ( P<0.05), while the addition of sham Exo had no neuroprotective effect. Conclusion:Exo released by cerebral vascular endothelial cells after IPC have protective effect on neurons suffering from OGD.