重型弥漫性颅脑损伤大鼠海马区Homer1a表达与神经细胞丢失的关系  

Relationship between Homer1a and nerve cell loss in hippocampus after severe diffuse brain injury in rats

作　　者：李建民[1] 赵雅宁[2] 马荣丽[2] 窦娜[2] 陈长香[2] 李淑杏[2] 张盼[2] 

机构地区：[1]河北联合大学附属医院神经外科,唐山医学博士063000 [2]河北联合大学康复医学院,唐山063000

出　　处：《医学研究生学报》2014年第8期797-801,共5页Journal of Medical Postgraduates

基　　金：河北省科技厅支撑课题(20276102D);河北省高等学校科学技术研究重点项目(ZD2010106)

摘　　要：目的 Homer1a是惟一在外来刺激后高表达的Homer家族蛋白。文中观察弥漫性颅脑损伤(diffuse brain injury,DBI)大鼠海马区Homer1a蛋白表达变化、凋亡神经细胞动态变化,以探讨重型DBI大鼠海马区Homer1a表达与神经细胞丢失的关系。方法按随机数字列表法将SD大鼠分为对照组(n=35)、DBI组(n=69)。Marmarou's法建立大鼠DBI模型。对照组不致伤。应用光镜和电镜下观察伤后脑组织形态变化;免疫组化及Western blot法检测海马区Homer1a表达,原位缺口末端标记法(in situ nick-end labeling,TUNEL)检测神经细胞的凋亡。结果 DBI组大鼠死亡率49.3%;其海马区神经元内细胞器、轴索及毛细血管等超微结构较对照组明显受损;伤后1 h DBI组存活神经细胞百分率较对照组显著降低[(94.4±5.6)%vs(99.4±0.6)%,P<0.05],伤后72 h降低最为显著[(54.7±33.8)%vs(99.2±0.8)%,P<0.05];Homer1a伤后1 h表达显著增高(0.136±0.024),6 h出现峰值(0.178±0.028),高表达状态持续至24 h(0.176±0.027)、48 h(0.145±0.02)和72h(0.117±0.012)表达下降,各时间点与对照组比较差异均有统计学意义(P<0.05);TUNEL阳性细胞凋亡指数,72h较对照组明显升高[(41.78±3.96)%vs(1.92±0.22)%,P<0.05]。相关分析显示1~24h Homer1a蛋白表达与存活神经细胞百分率呈负相关(r=-0.726,P<0.05),与TUNEL阳性细胞数量呈正相关(r=0.738,P<0.05);24~72 h Homer1a蛋白表达与TUNEL阳性细胞数量呈负相关(r=-0.898,P<0.05),与存活神经细胞百分率呈正相关(r=0.842,P<0.05)。结论重型DBI后海马区Homer1a蛋白动态表达可反映神经细胞丢失。（DBI） in rats by observation on the changes of Homer 1a expression and apoptotic nerve cells . Methods Spraque-Dawlley（SD） rats were randomly （ random number ） divided into control group and severe DBI group .DBI rat model was established according to the de-scription of Marmarou′s diffused brain injury .No injury was done on control group .The changes of neuron pathology were observed by light microscopy and electron microscope .The expression of Homer1a was observed by immunohistochemistry and western blot .The quan-tity of apoptotic cells was measured by terminal deoxynucleotidyl transfernase medicated nick end labeling （ TUNEL） method. Results The death rate of rats in severe DBI group was 49.3%.Compared with the control group , the ultrastructures in hippocampal neurons in-cluding organelle , axonal and capillary were damaged seriously after injury , the survival rate of nerve cells decreased significantly at 1 h after injury （[99.4 ±0.6]%vs [94.4 ±5.6]%, P〈0.05）, and peaked at 72 h （[99.2 ±0.8]%vs [54.7 ±33.8]%, P〈0 .05） in DBI group.The expression of Homer1a protein increased significantly at 1 h after injury（0 .136 ±0.024 ）and peaked at6 h（0.178 ± 0.028） and maintained to 24 h （0.176 ±0.027）, while decreased at 48 h （0.145 ±0.02）and 72 h （0.117 ±0.012） in DBI group;the expression of Homer 1a was obviously higher at each time point in DBI group than that in control group （P 〈0.05）.The apoptoticindex of TUNEL positive cells increased at 6 h and demonstrated significant difference at 72h in comparison to control group （[41.78 ±3 .96]%vs [1.92 ±0.22]%, P〈0.05）.The correlation analysis indicated that Homer1a expression from 1~24 h and 24 h^72 h was related to the survival rate of nerve cells （ r=-0.726, P〈0.05; r=0.842, P〈0.05） and the quantity of TUNE positive cells（r=0.738, P〈0.0;5 r=-0.898, P〈0.05）. Conclusion The dynamic expression of Homer1a in hippocampus after severe DBI can reflect nerve cell loss.

关 键 词：重型弥漫性脑损伤 Homer1a 凋亡 大鼠 

分 类 号：R651[医药卫生—外科学]