Cdk5／p35和tau蛋白对戊四氮点燃模型海马苔藓纤维出芽的作用  

Involvement of Cdk5/p35 and tau protein in the hippocampal mossy fiber sprouting in the PTZkindling model

作　　者：田发发[1] 郭婷辉[2] 党静[1] 马云峰 陈金梅[4] 陈莹 蔡小凤[6] 宋明谕[1] 

机构地区：[1]中南大学湘雅医院神经内科,长沙410008 [2]福建医科大学附属漳州市医院神经内科 [3]北京市三博复兴脑科医院 [4]上海市普陀区人民医院神经内科 [5]长沙市第一医院神经内科 [6]中南大学湘雅医院妇产科

出　　处：《中华医学杂志》2011年第17期1197-1202,共6页National Medical Journal of China

基　　金：湖南省研究生科研创新项目（234074333001137）

摘　　要：目的动态观察细胞周期素依赖性激酶5（Cdk5）及调节亚基p35、骨架蛋白在戊四氮致痫大鼠海马各区的表达变化和苔藓纤维出芽（MFS）的情况，以探讨Cdk5／p35对MFS的作用及其机制。方法SD雄性成年大鼠240只，随机分为PTZ组和对照组；PTZ组分为PTZ第一次注射后3d、l周、2周、4周、6周共5个业组，每业组24只，对照组随机分为5个业组，与PTZ组各时间点对应。以上各亚组再分4个小组，每小组6只大鼠，分别进行（1）Timm染色并评分；（2）Cdk5／p35的免疫组化和原位杂交；（3）Cdk5活性测定；（4）tau蛋白表达及磷酸化水平（免疫组化和免疫印迹）。结果PTZ组CA3区苔藓纤维出芽最为明显，而非内分子层，苔藓纤维出芽的程度与点燃大鼠痫性发作的行为学表现一致；PTZ组Cdk5／p35 mRNA和蛋白、总tau蛋白和P－ptau（ser202）蛋白在3d时表达增多，4周达高峰，6周时接近正常水平，与CA3区苔藓纤维出芽的过程一致。对照组无动态变化。结论Cdk5／p35及其底物tau蛋白可能参与了苔藓纤维出芽，了解苔藓纤维出芽的机制，有助于抑制癫痫的发生。Objective To observe the expression of cyclin-dependent kinase 5 （Cdk5）, p35, tau protein and the activity of Cdk5 in rat hippocampus during pentylenetetrazole （PTZ） kindling process and their correlation with mossy fiber sprouting （MFS） so as to investigate the role of CdkS/p35 in cpilcptogenesis. Methods A total of 240 healthy male SD rats were divided randomly into normal controls and pentylenetetrazole （PTZ） treatment groups. The epileptic models were established by injection of PTZ intraperitoneally. At Day 3, Weeks 1, 2, 4 ＆ 6 after a daily injection of PTZ, Timm staining was scored in the CA3 region and dentate gyrus. At the same time, the mRNA and protein of Cdk5 and p35, total tan protein and its phosphorylation at set202 and Cdk5 activity were analyzed in the hilus and stratum granulosum of dentate gyrus and the CA1, CA3 regions of hippocampus. The methods of in situ hybridization,immunohistochemistry, Western blot and immuno-precipitation and liquid scintillation counter were employed respectively. Results Prominent MFS was observed in area CA3 rather than the inner molecular layer in PTZ-treated rats. And the degree of MFS progressed with the development of behavioral kindled seizures. The expressions of CdkS/p35 mRNA and protein, tau protein and its phosphorylation at Set202 significantly increased from Day 3 to Week 4 in the PTZ treatment group. It was in accordance with the progression of MFS in area CA3. Conclusion CalkS/p35 and its substrate tau protein may be involed in MFS. Understanding the molecular mechanisms of MFS may lead to therapeutic interventions for limiting epileptogenesis.

关 键 词：戊四氮 细胞周期素依赖性激酶5 TAU蛋白 苔藓纤维出芽 颞叶癫痫 

分 类 号：R742.1[医药卫生—神经病学与精神病学]