缺氧缺血再灌注新生鼠磷酸化的环磷酸腺苷反应元件结合蛋白、神经生长因子对神经元的保护作用  

Protective Effect of Phosphorylatin Cyclic Adenosine Monophosphate Response Element Protein and Nerve Growth Factor on Neurons after Hypoxic-Ischemic Brain Damage and Reperfusion in Rats

作　　者：任广立[1] 方颖[2] 马恒颢[1] 许蔓春[1] 罗爱武[1] 欧巧群[1] 王鲜艳[1] 王丹[1] 谢祥鳌[1] 

机构地区：[1]广州军区总医院儿科 [2]广州医学院口腔系,广州510010

出　　处：《实用儿科临床杂志》2007年第24期1857-1859,共3页Journal of Applied Clinical Pediatrics

摘　　要：目的探讨神经元的抗凋亡保护机制,评价环磷酸腺苷(cAMP)反应元件结合蛋白(CREB)、神经生长因子(NGF)对神经元损伤后的保护作用。方法7日龄Sprague-Dawley新生大鼠随机分为假手术组、缺氧缺血性脑损伤(HIBD)未治疗组、小干扰RNA(siRNA)治疗组、siRNA加NGF治疗组。按照改良的Rice法制备HIBD再灌注模型,各治疗组于再灌注后开始予1次siRNA干预治疗(10mg/kg);siRNA加NGF组予NGF(15μg/kg),1次/d。于治疗的不同时间通过免疫组织化学和Western blot法检测磷酸化的CREB、NGF在仔鼠HIBD再灌注后海马、丘脑神经元的表达变化。通过Thionine染色检测神经元凋亡。结果HIBD未治疗组3h仔鼠右侧海马CA1区磷酸化的CREB(p-CREB)表达达高峰,7d后降至假手术对照水平。3hNGF表达开始增加,12h持续达高峰,7d后仍明显高于假手术组(P<0.05)。siRNA治疗组p-CREB与NGF表达随时间逐渐下降。HIBD再灌注未治疗组24h右侧海马CA1区已有明显的凋亡,7d神经元凋亡与假手术组相比无统计意义。siRNA治疗组神经元有大量的丢失;而siRNA加NGF治疗组神经元与假手术组比较无明显丢失。结论CREB经信号转导调节大鼠NGF的表达,从而促进其神经元损伤后修复,减少神经元死亡。Objective To explore the mechanism of anti - apoptosis and evaluate the protective role of cyclic adenosine monophesphate （cAMP） response element binding protein （ CREB ） and nerve growth factor （NGF） on damaged neurons. Methods Seven - day - old Sprague - Dawley rats were used to prepare the animal model of hypoxic - ischemic brain damage （HIBD） according to the improved rice method. Four groups were set as follows： sham operated group, untreated HIBD group, small interference RNA （siRNA） treated HIBD group, siRNA and NGF treated HIBD group. Each treated group was injected with siRNA （ 10 mg/kg） for one time, and NGF （ 15 μg/kg） for once daily. The immunohistochemistry and Western blot were carried out to detect the expressions of CREB and NGF in hippocampus and thalamic neurons. At the same time,the apoptosis of neuron was observed by Thionine staining. Results The expression of phosphorylation monophosphate CREP（p - CREB） reached the peak in the CA1 region of right hippocampus after 3 h of reperfusion in HIBD untreated group, and it decreased to the level of sham control group after 7 d. Meanwhile in the untreated group, the NGF increased at 3 h post - reperfusion and remained at the very high level at 12 h post- reperfusion, which was still very higher than that of the sham operated control at 7 d （P 〈0.05 ）. The expressions of p - CREB and NGF were very low in the siRNA treated group. The apoptosis of CA1 neurons in right hippocampus was marked after 24 h in untreated group, while the apoptosis of neurons was not significant compared with sham operated group. But there were large number of neurons lost in the siRNA treated group. Furthermore the neurons were almost not loss in the siRNA and NGF treated group. Conclusions p - CREB regulates the expression of NGF through the signal transductions. They participate in the neurons＇ survival, regeneration, and repair during the period of post hypoxic - ischemic reperfusion. It is very important to protect the sensitive re

关 键 词：缺氧缺血 脑损伤 环磷酸腺苷反应元件结合蛋白 神经生长因子 小干扰核糖核酸 鼠 新生 

分 类 号：R722.1[医药卫生—儿科]