半胱氨酸蛋白酶在实验性癫痫神经元损伤中的作用

The expression of caspase-3 in neuronal damage of the experimental epilepsy

目的:通过观察实验性癫痫发作时海马半胱氨酸蛋白酶(Caspase-3)表达变化,探讨神经元损伤及癫痫发病机制。方法:利用锂-匹罗卡品(Li-PC)制作大鼠急性癫痫持续状态(SE)30min、1h、2h的癫痫模型,造模后1d、3d、7d、14d,经流式细胞技术(FCM)半定量检测Caspase-3的表达含量,并应用光镜及电镜进行神经元形态学观察。结果:模型组海马内Caspase-3表达与SE早期持续时间呈正相关(SE30min3.51±0.35,1h4.49±0.14,2h7.39±0.26p<0.001);各组中均可见Caspase-3表达1d活化,7d表达达峰值(SE30min组1d时3.51±0.35,7d时10.34±0.36;1h组1d时4.49±0.14,7d时14.33±0.33;2h组1d时7.39±0.26,7d时31.15±0.79;p<0.01)。电镜下细胞超微结构凋亡、缺失明显,以海马门区、CA1区为著。结论:Caspase-3是神经元凋亡关键的执行因子,它可以反映SE对神经元造成损伤程度。急性期SE所致的海马区缺血缺氧、水肿以及兴奋毒性导致神经元损伤,可能是慢性颞叶癫痫的病理基础。

Objective：To explore the role of neuronal damage and epileptic pathogenesis by observing expression of caspase-3 in hippocampus.Methods：At 1,3,7,and 14d after the rat lithium-pilocarpine epilepsy model completed,the morphology of neuron were suyvered by light and electron microscope,the semi-quantitative contents of cysteine proteinase caspase-3 were detected by flow cytometry（FCM）.Results：The increase of caspase-3 values in model group positively correlated With the duration of status epilepticus（SE）（p〈0.001）.Compared with the control group in hippocampus,the expression of active caspase-3 was detected at 1d,increased at 7d（p〈0.01）.Corresponding to high levels active caspase-3 expression,neuronal apoptosis and loss was most pronounced in morphous,especially in hilus,CA1 obtained by microscop after 7 days.Conclusion：Caspase-3 may play a key role in process of neuronal apoptosis,and demonstrate the degree of neuronal damage.It could be underlied in the pathogenesis that the acute seizure of chronic temporal lobe epilepsy induce ischemic hypoxia,edema or exitotoxicitic neuron damage in hippocampus.