缺氧缺血性新生大鼠脑皮质氧化还原因子-1蛋白的表达

The expression of Ref-1 protein in the cerebral cortex area of neonatal rats after brain hypoxia-ischemia

目的 :探讨新生大鼠脑组织缺氧缺血后 ,氧化还原因子 -1(APE/Ref-1)蛋白在脑皮质不同时相的表达及其意义。方法 :将新生7日龄SD大鼠制成缺氧缺血性脑损伤(HIBD)动物模型 ,采用免疫组织化学方法及原位缺口末端标记 (TUNEL)法分别观察正常对照组、假手术组及缺氧缺血1、3、6、12、24、48小时APE/Ref-1蛋白及神经细胞凋亡变化 ,分析两者关系。结果 :氧化还原因子 -1蛋白在正常对照组、假手术组及右侧大脑半球神经细胞核广泛表达 ;而缺氧缺血组脑皮质区该蛋白表达随缺血时间的延长而下降 ,且各时间点间差异显著。脑皮质区凋亡阳性细胞表达脑皮质区与APE/Ref-1相反 ,其随缺血时间的延长逐渐增多 ,并在24小时达到高峰。结论 :新生大鼠脑组织缺氧缺血后 ,脑皮质区神经元APE/Ref-1蛋白表达减少,凋亡细胞表达增加,提示APE/Ref-1蛋白减少和DNA修复功能失败可能与脑缺氧缺血后神经细胞凋亡的发生有关。

Objective:To explore the characteristic of the expression of Ref-1protein in the cerebral cortex area of neonatal rats after brain hypoxia-ischemia at differented time.Medthods:The HIBD model was established with7-old-day SD neonatal rats,The expression of Ref-1protein and apoptosis as well as the both relationship were determined by immunohistochemistry and terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling(TUNEL)staining following the normal control group,sham,operation group and the hypoxic-ischemic group with intervals of1,6,12,24,48h and72h,respectively.Results:Immunohistochemistry showed the nuclear expression of Ref-1in the normal control group,sham operation group and right cerebral hemisphere.In the hypoxic-ischemic group,nuclear immunoreactivity of Ref-1protein was deˉcreased along with the extension hypoxic-ischemic time in the cerebral cortex.The difference among those groups was significant(p<0.05).Contrary,apoptotic cells were increased gradually,reached peak after24h.Conclusion:Our results with the decrease of Ref-1protein and increase of apoptotic cells in the cerebral cortex suggest that the reduction of Ref-1and the failure of DNA repairing mechanism may be conˉtributed to the apoptosis after cerebral hypoxia-ischemia.