COX-2抑制剂抑制幼鼠癎性发作后MARK／ERK信号的活化

COX-2 inhibitors inhibit the activation of MARK/ERK signal transduction pathway

目的：探讨环氧合酶-2（COX-2）抑制剂抑制幼鼠癎性发作后丝裂素蛋白激酶／细胞外调节蛋白激酶（MARK／ERK）信号转导通路的变化。方法：模型制作：随机将120只体重为50～60g的3周龄健康Wistar幼鼠分为匹鲁卡品致癎组（EP—only组）（rt-45）和塞莱昔布干预致癎组（EP—cel组）（n=45）和生理盐水正常对照组（n=30）3组；各实验组分别在急性发作后第14d，28d处死大鼠制备组织切片。免疫组织化学方法检测磷酸化细胞外调节蛋白激酶（p-ERK1／2）及C-los蛋白阳性细胞在各组的表达变化趋势，Westernbolot方法检测ERKI／2及p-ERK1／2）及C-los蛋白水平在癎性发作后1h、1d、4d、7d、14d、28d各时点的表达及变化趋势。结果：癫癎持续状态（SE）后14d，EP—only组P—ERKl／2阳性细胞数量约为正常对照组的8倍，EP—cel组阳性细胞数较EP—only组表达明显减少；EP—only组C—los免疫阳性细胞（65±10）较EP—cel组（48±9）明显增高（ANOVA，p〈O．05）。SE后1hEP—only组p-ERK1／2蛋白水平迅速升高，1d达高峰为正常组的近10倍，EP—eel组各时点p-ERK1／z表达显著低于EP—only组（P〈O．01）。ERK1／2在海马的表达强度高于p-ERK1／2。EP-cel组各时点c—fos蛋白表达显著低于相应时间点的EP-only组。结论：COX-2抑制剂逆转海马异常可塑性的发生是通过抑制痢性发作激活的MARK／ERK信号转导途径及其下游信号分子C-los而发挥效应。

Objective：To investigate the effect of the COX-2 inhibitor on MARK/ERK signal trans- duction pathway after immature seizures. Methods：3-week-old Wistar rats （n= 120） were randomly divided into three groups： pilocarpine-induced epilepsy group （EP-only group）, Celecoxib treatment epilepsy group （EP-cel）, and normal saline control group（Control）. In each experimental group preparing tissue sections of rats were sacrificed on Day 14 and 28 respectively after the acute attack. Immunohisto- chemical methods were sued to detect the expression trend of p-ERK 1/2 and C-fos postive cells in each group, western blot was used to detect ERK 1/2,phosphorylated ERK 1/2 （p-ERK1/2） and C-los protein levels at each time point at 1 st d,4 th d,7 th d,14 th d and 28 th d the size of d after seizures. Resuits：In EP-only group, positive p-ERK 1/2 cells were eight times the size of the Control group. In EP- cel group, the number of positive cells were significantly reduced compared with EP-only group. C-fos immunoreactive cells in EP-only group were higher than in EP-cel group （65＋ 10 vs 48＋9）. p-ERK 1/2 levels increased rapidly,which reached a peak of nearly 10 times after 1 d, EP-cel group at each time point was significantly lower than in EP-only group （P〈0.01）. ERK 1/2 expression intensity was high- er than p-ERK 1/2. C-fos protein expression at each time point in EP celecoxib group was significantly lower than at the corresponding lime point in EP-only group. Conclusion： COX-2 inhibitors reversed the hippocampus abnormal plasticivy through the inhibition of the activation of MAPK/ERK signal transdue tion and its downstream signaling molecules C-fos.