OBJECTIVETo study the effect of astrocyte exosomes on hypoxic-ischemic neurons.

METHODSRat astrocytes were cultured in vitro, and differential centrifugation was used to obtain the exosomes from the cell supernatant. Transmission electron microscopy, Nanosight, and Western blot were used for the identification of exosomes. BCA method was used to measure the concentration of exosomes. Rat neurons were cultured in vitro and then divided into control group, exosome group, oxygen glucose deprivation (OGD) group, and OGD+exosome group (n=3 each). The OGD and OGD+exosome groups were cultured in glucose-free medium under the hypoxic condition. The exosome and OGD+exosome groups were treated with exosomes at a final concentration of 22 μg/mL. The control and OGD groups were given an equal volume of phosphate-buffered saline. ELISA was used to measure the level of lactate dehydrogenase (LDH) in neurons. The terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling was used to measure the apoptotic index of neurons.

RESULTSThe identification of exosomes showed that the exosomes extracted by differential centrifugation had the features of exosomes. Compared with the control and exosome groups, the OGD group had significant increases in LDH level and apoptotic index (P<0.05). Compared with the OGD group, the OGD+exosome group had significant reductions in LDH level and apoptotic index (P<0.05).

CONCLUSIONSThe exosomes from astrocytes have a protective effect on neurons with hypoxic-ischemic injury.