Tian Fa-fa, Guo Ting-hui, Dang Jing, Ma Yun-feng, Chen Jin-mei, Chen Ying, Cai Xiao-feng, Song Ming-yu
Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, China.
Zhonghua Yi Xue Za Zhi. 2011 May 10;91(17):1197-202.
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 Cdk5/p35 in epileptogenesis.
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 tau protein and its phosphorylation at ser202 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.
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 Cdk5/p35 mRNA and protein, tau protein and its phosphorylation at Ser202 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.
Cdk5/p35 and its substrate tau protein may be involved in MFS. Understanding the molecular mechanisms of MFS may lead to therapeutic interventions for limiting epileptogenesis.
观察戊四氮（PTZ）点燃过程中大鼠海马细胞周期蛋白依赖性激酶5（Cdk5）、p35、tau蛋白的表达及Cdk5活性，及其与苔藓纤维出芽（MFS）的相关性，以探讨Cdk5/p35在癫痫发生中的作用。
将240只健康雄性SD大鼠随机分为正常对照组和戊四氮（PTZ）治疗组。通过腹腔注射PTZ建立癫痫模型。每日注射PTZ后第3天、第1、2、4和6周，对CA3区和齿状回进行Timm染色评分。同时，分析齿状回门区和颗粒层以及海马CA1、CA3区Cdk5和p35的mRNA和蛋白、总tau蛋白及其丝氨酸202位点的磷酸化水平以及Cdk5活性。分别采用原位杂交、免疫组织化学、蛋白质印迹、免疫沉淀和液体闪烁计数器检测。
在PTZ处理的大鼠中，CA3区而非内分子层观察到明显的MFS。并且MFS的程度随着行为性点燃发作的发展而进展。PTZ治疗组从第3天到第4周，Cdk5/p35 mRNA和蛋白、tau蛋白及其丝氨酸202位点的磷酸化水平显著增加。这与CA3区MFS的进展一致。
Cdk5/p35及其底物tau蛋白可能参与MFS。了解MFS的分子机制可能会带来限制癫痫发生的治疗干预措施。
