托吡酯对遗传性癫痫大鼠脑内GAT-1和GAT-3表达的影响

目的探讨托吡酯对TRM大鼠脑内GAT-1和GAT-3 mRNA和蛋白表达的影响。方法分别应用实时定量PCR法和Western blot方法检测Wistar正常组、TRM组、TPM40组和TPM80组脑内GAT-1和GAT-3 mRNA和蛋白表达。结果 GAT-1、GAT-3和β-actin标准曲线相关性良好,基因特异性强。GAT-1 mRNA在TRM组的海马高于正常组(P<0.01);与TRM组比较,TPM80组海马中GAT-1 mRNA明显降低(P<0.05);GAT-3 mRNA在TRM组海马中的表达高于正常组(P<0.05);GAT-1蛋白表达在TRM组的海马高于正常组(P<0.01);与TRM组比较,TPM80组海马中GAT-1蛋白明显降低(P<0.01);GAT-3蛋白在TRM组海马中的表达高于正常组(P<0.05)。结论 TRM组海马内GAT-1及GAT-3的表达增加可能促进了癫痫的发生。托吡酯的抗癫痫作用可能是通过降低海马内GAT-1的表达来实现的,这种调节存在剂量依赖性。

Effects of topiramate on the expressions of GAT-1 and GAT-3 in genetically epileptic rat brain

Aim To investigate the effects of topiramate on genetic and protein levels of GAT-1 and GAT-3 in the hippocampus of TRM rat. Methods The mRNA and protein expressions of GAT-1 and GAT-3 in the four groups,namely,control,TRM,TPM40 and TPM80 groups were determined via SYBR Green Ⅰ quantitative real-time PCR and Western blot,respec-tively. Results The calibration curve showed a good linearity. Besides,a high specificity was observed through agarose gel electrophoresis and melting curves analysis. The mRNA and protein relative expressions of GAT-1 in TRM hippocampus were both significantly increased compared with control group ( P < 0. 01) . In the meantime,markedly decreased GAT-1 expressions at the mRNA and protein levels were obtained in TPM80 group ( P < 0. 01) while no change appeared in TRM40 in comparison to TRM group. We also observed the marked increase of GAT-3 mRNA and protein in the hippocampus of TRM ( P < 0. 05,P < 0. 01) . Conclusions The up-regulation of GAT-1 and GAT-3 in TRM hippocampus may contribute to the generation of seizure. At the same time,the anti-epileptic mechanism of topiramate is probably through decreasing the ex-pression of GAT-1 in hippocampus in a dose-dependent way.