DKK1 mRNA在红藻氨酸致痫大鼠颞叶癫痫形成中的变化

Change of DKK1 mRNA in the Process of Epileptogenesis in the Kainate-induced Epilepsy Model

目的观察Wnt/β-catenin信号通路抑制剂DKK1在红藻氨酸致痫大鼠在颞叶癫痫形成中的表达规律及丙戊酸钠对DKK1mRNA基因表达的影响。方法利用出生30d的雄性SD大鼠,经皮下注射KA制成颞叶癫痫动物模型后,应用Real-time PCR技术检测KA后1周、4周和8周三个时间点大鼠海马组织中DKK1的表达,并观察抗癫痫药物丙戊酸钠对DKK1表达的影响。结果研究结果显示KA致痫后在颞叶癫痫形成过程中,KA组动物海马组织DKK1 mRNA的表达同生理盐水(NS)对照组(1.00±0.00)相比,在急性期显著下降(0.42±0.17,P=0.000),在自发性反复癫痫形成初期,较急性期表达增高但无统计学意义(1.04±0.24,P=0.896),至慢性癫痫稳定形成期较前两时期均明显增高且差异有显著性(1.35±0.25,P值分别为0.000,0.045)。红藻氨酸+丙戊酸钠(KA+VPA)组大鼠海马组织DKK1 mRNA的表达,同NS组相比在急性期表达显著下降(0.65±0.26,P=0.008),在慢性癫痫稳定形成期表达显著增高(1.30±0.31,P=0.039)。在慢性期的表达较急性期(0.65±0.26)和癫痫形成初期(0.94±0.18)均显著增高且有统计学意义(1.30±0.31,P值分别为0.003,0.033)。KA+VPA组和KA组之间大鼠海马组织DKK1mRNA的表达在KA点燃后颞叶癫痫形成的不同阶段差异均无显著性。结论 DKk1可通过抑制Wnt/β-catenin信号通路参与颞叶癫痫的形成,丙戊酸钠的抗痫作用机制与大鼠海马DKK1信号分子无关。

Objective To detect the expression of DKK1,an inhibitor of Wnt/β-catenin signaling pathway,in the formation of temporal lobe epilepsy in rats with kainite-induced seizures and to explore the effects of the valproate on the gene expression of DKK1 mRNA. Methods Sprague-Dawley rats were induced by kainic acid（ KA） at postnatal 30 days,and Real-time PCR method was applied to detect the expression of DKK1 mRNA in the hippocampus in one week,4 weeks and 8 weeks after KA kindling,meanwhile whether VPA could affect the expression of DKK1 mRNA in the hippocampus during the epileptogensis was investigated. Results After KA-induced epilepsy occurred,the expression of hippocampal tissue DKK1 mRNA fell significantly（ 0. 42 ± 0. 17,P = 0. 000） compared with NS group（ 1. 00 ± 0. 00） during the acute stage in the formation of temporal lobe epilepsy. At the initial stage,DKK1 mRNA in the hippocampus increased（ 1. 04 ± 0. 24,P = 0. 896）,but the difference was not statistically significant. While the expression during the stable formation of chronic epilepsy was higher（ 1. 35 ± 0. 25,P values respectively are 0. 000,0. 045） than that of the previous two periods with statistic significance. The expression of hippocampal tissue DKK1 mRNA in the kainate ＋ valproate（ KA ＋ VPA） group,compared with NS group,dropped significantly（ 0. 65 ± 0. 26,P = 0. 008）. But the expression elevates at chronic stage（ 1. 30 ± 0. 31,P = 0. 039）,and the difference has statistical significance. The expression during the chronic phase was higher than that of the acute phase（ 0. 65 ± 0. 26）,and the early formation of epilepsy（ 0. 94 ± 0. 18） had statistical significance（ 1. 30 ± 0. 31,P respectively values were 0. 003,0. 033）. At different stages of epileptogenesis,Wnt5 a mRNA expression in the hippocampus had no significant differences between KA group and KA ＋ VPA group. Conclusion DKk1 may participate in the formation of temporal lobe epilepsy by inhibiting the Wnt/β-catenin signaling pathway. The antiepileptic mechanism of valproate acid is not related to DKK1 in this epileptic model.