Changes of neuronic apoptosis, Rho GDP dissociation inhibitor 2 and Bd-2 in brain tissue of neonatal rats with hypoxic-ischemic brain damage / 中国小儿急救医学

ABSTRACT

Objective To investigate the effect of Rho GDP dissociation inhibitor 2 (RhoGDI2) and Bcl-2 in pathogenesis of hypoxic-ischemic brain damage (HIBD).Methods Neonatal 7-day-old Sprague Dawley rats were randomly divided into sham-operation control group,HIBD 6 h group and HIBD 48 h group (n =10 per group).The apoptosis rate of brain cell was measured by flow cytometer and the expression of RhoGDI2 mRNA and Bcl-2 mRNA were detected by Real-time RT-PCR.Results ( 1 ) The ligated cerebral hemisphere of neonatal rats showed obvious edema at 48 h after hypoxia-ischemia.( 2 ) Apoptotic cell appeared at 6 h in HIBD group,the apoptosis rate was ( 1.40 ± 0.12 ) ％.The apoptosis rate obviously increased to (15.86 ±0.98)％ at 48 h after HIBD,which showed a significant increase compared to sham-operation control group ( P ＜ 0.01 ).( 3 ) The expressions of both RhoGDI2 mRNA and Bcl-2 mRNA were 4.12 ±0.74 and 2.55 ± 0.65 respectively in sham-operation control group.In HIBD group,the expressions of both RhoGDI2 mRNA and Bcl-2 mRNA began to decrease at 6 h after HIBD ( 3.19 ± 0.77,1.96 ± 0.36) and decreased furthermore at 48 h after HIBD ( 1.04 ±0.18,1.06 ±0.17 ).The differences of expression levels among three groups were statistically significant (P ＜0.01 ).(4) The expression of RhoGDI2 mRNA positively correlated with the expression of Bcl-2 mRNA ( r =0.831,P ＜ 0.05 ).Conclusion With the emerging of apoptosis after HIBD,the expressions of both RhoGDI2 mRNA and Bcl-2 mRNA are decreased.The imbalance of expression of RhoGDI2 is involved in pathogenesis of HIBD by regulating Bcl-2 expression.