脑源性神经营养因子mRNA及其受体酪氨酸激酶B在胆红素脑损伤新生豚鼠皮质及海马的表达  

Expressions of Brain-Derived Neurotrophic Factor mRNA and Tyrosine Receptor Kinase B in Cerebral Cortex and Hippocampus of Guinea Pigs with Bilirubin Encephalopathy

作　　者：何平[1] 朱萍[1] 李水冰[2] 祝大丽[1] 

机构地区：[1]昆明医学院第二附属医院儿科,昆明650101 [2]云南大学生命科学院重点实验室,昆明650000

出　　处：《实用儿科临床杂志》2011年第2期138-141,共4页Journal of Applied Clinical Pediatrics

基　　金：云南省教育厅重点基金(037Z520C)

摘　　要：目的探讨新生豚鼠胆红素脑神经损伤时脑源性神经营养因子(BDNF)mRNA及其受体酪氨酸激酶B(TrKB)在大脑皮质及海马的表达特点。方法取出生2～5d豚鼠60只,随机分为3组,C组为对照组;T1组:腹腔注射晶体胆红素1mg·kg-1;T2组:腹腔注射晶体胆红素2mg·kg-1,分别在4h、8h处死。做脑组织切片,电镜、光镜观察其病理改变,并采用免疫组织化学、原位杂交和图像分析,观察不同时间点BDNFmRNA、TrKB在皮质及海马的表达变化。结果胆红素脑神经损伤模型成功建立。1.C组BDNFmRNA和TrKB在皮质及海马也有少量的表达;2.随时间延长和损伤加重,T1组和T2组皮质及海马的BDNFmRNA和TrKB表达明显上升,4h时T1组、T2组与C组比较,BDNFmRNA表达明显上升(P<0.05),T1组和T2组4h和8h比较,BDNFmRNA表达降低(P<0.05);3.TrKB在皮质和海马的表达也是随时间延长和损伤加重表达增加,4h、8h时T1组、T2组与C组比较,表达是增加的(P<0.05),T1组4h、8h与T2组8h比较,TrKB的表达是降低的(P<0.05)。结论胆红素脑神经损伤中,皮质和海马BDNFmRNA、TrKB升高可能减轻神经元损伤,在抑制神经元凋亡和神经元修复中发挥重要作用,有利于神经元修复和再生,可能是胆红素脑神经元损伤时机体的自我保护机制之一。Objective To investigate the expression characteristics of brain-derived neurotrophic factor（BDNF）mRNA and tyrosine receptor kinase B（TrKB）in the cerebral cortex and hippocampus of the newborn Guinea pigs with bilirubin encephalopathy.Methods Sixty newborn Guinea pigs（2-5 days old）were divided into 3 groups at random：control group,T1 group and T2 group.Each member of T1 group and T2 group was injected with crystal bilirubin（1 mg·kg-1）or（2 mg·kg-1）respectively via peritoneal injection and then executed（T14 h and T18 h;T24 h and T28 h）.Brain tissue slices were made to observe the pathological changes by the electron microscope and the optical microscope.Immunohistochemistry,in situ hybridization and image analysis were adopted for the observation of the changes in the expressions of BDNF mRNA and TrKB at different times.Results Bilirubin encephalopathy models were successfully established.1.There were also some expressions of BDNF mRNA and TrKB in the cerebral cortex and hippocampus region in the control groups.2.With the passage of time and aggravation of damage,the expressions of BDNF mRNA were obviously increased in group T1 and group T2.The expressions of BDNF mRNA of T14 h and T24 h were significantly higher than those of the control groups（P0.05）.However,the expressions of BDNF mRNA of T14 h and T24 h were significantly lower than those of T18 h and T28 h（P0.05）.3.The expressions of TrKB in cerebral cortex and hippocampus of the T1 and T2 groups also increased with the passage of time and aggravation of damage.Compared with the control groups（4 h and 8 h）,the expressions of TrKB of T1（4 h and 8 h）and T2（4 h and 8 h）increased significantly（P0.05）.However,the expressions of TrKB of T14 h and T18 h were significantly lower when compared with those of T18 h and T28 h（P0.05）.Conclusions In bilirubin neuronal damage,the increase of BDNF mRNA and TrKB in cerebral cortex and hippocampus might reduce damage of neurons and play an important role in restraining the

关 键 词：胆红素脑病 脑损伤 脑源性神经营养因子 酪氨酸激酶B 

分 类 号：R722.1[医药卫生—儿科]