Expressions of p75NTR, Bax and Bcl-2 and cell apoptosis in rat cortical neurons following mechanical injury / 中华创伤杂志

ABSTRACT

ObjectiveTo study the expressions of p75NTR,Bax and Bcl-2 and cell apoptosis in rat cortical neurons following mechanical injury and discuss the mechanism and mutual action way during the apoptosis of rat neurons after mechanical injury.Methods Cortical neuron cultures were prepared from the brain tissues of day 17 rat embryos and were exposed to mechanical injury seven days after seeding.After the traumatic neuron injury models were created,the apoptosis ratio of neurons was tested at several time points.The models were divided into the minor,moderate,severe injury groups according to the injury severity and the control group.The expressions of Bax and Bcl-2 in each group were detected by immunohistochemistry method and that of p75NTR by Western-blot.Combining with cellular apoptosis ratio in each group shown after FCM analysis,the correlation between the expressions of p75NTR,Bax and Bcl-2 and the apoptosis in rat neurons after mechanical injury could be analyzed.ResultsThe apoptosis ratio of the neurons in all the injury groups was obviously higher than that in the control group,with significantly higher apoptosis ratio of the neurons in the severe injury group than the minor and moderate injury groups (P ＜0.05).P75NTR,Bax and Bcl-2 were all expressed in all the injury groups,with statistical differences between groups.The expression of Bax in the severe injury group was significantly higher than that in the minor and moderate injury groups(P ＜ 0.05 ). Conclusions p75NTR expression and Bax/Bcl-2 ratio are closely correlated with neuron apoptosis.The early expression of p75NTR may be one of mechnisms for neuronal apoptosis after neuron injury,when Bax and Bcl-2 may be involved.