Objective     To identify the relationship between the polymorphisms of apolipoprotein E gene (APOE) and the changes of excitatory amino acids (EAAs) in injured astrocytes.     Methods     Astrocytes were separated from APOE gene-knockout newborn rat cerebral cortex and then identified by GFAP-FITC immunofluorescence staining. The recombinant plasmids pEGFP-N1-APOEε2

pEGFP-N1-APOEε3

and pEGFP-N1-APOEε4 were respectively transfected into the isolated astrocytes with Lipofectamine 2000. Subcellular localization of APOE and transfection efficiency were observed by fluorescent microscopy. RT-PCR was applied to detect the expression of APOE in the astrocytes after transfection. Scratched models of the 3 genotypes astrocytes were produced

and the content of amino acids were measured by amino acid analyzer. Cell apoptosis was detected by flow cytometry (FCM).     Results     The level of Glu and Asp in the astrocytes after scratching injury reached a peak at 30 min. APOEε4 transfected astrocytes released higher levels of Glu and Asp compared with those in the other 2 groups at 30 and 60 min after injury (P0.05). FCM showed that the apoptotic rate reached a peak at 24 h. APOEε4 group had significantly higher apoptotic rate than the other 2 groups at 12 and 24 h after injury (P0.05).     Conclusion     APOE affects the contents of EAAs released from the astrocytes after injury in an isoform-specific manner. APOEε4 carriers may induce more severe deterioration and poorer prognosis because of EAAs toxicity.