EGCG通过抑制p75^(NTR)通路对APP/PS1小鼠学习记忆障碍的改善作用

EGCG ameliorating learning and memory impairment in APP/PS1 mice by inhibiting p75^(NTR) pathway

目的探讨(-)表没食子儿茶素没食子酸酯(epigallocatechin-3-gallate,EGCG)对APP/PS1转基因小鼠学习记忆障碍的改善作用及其对海马内p75NTR信号通路及其介导的神经细胞凋亡的影响。方法以Morris水迷宫及被动避暗实验观察其行为学变化,TUNEL法及fluoro-Jade B法检测神经细胞凋亡及神经元退行性变,并以Western blot法检测小鼠海马p75NTR相关蛋白的表达水平。结果 EGCG可明显改善APP/PS1转基因小鼠的学习记忆障碍,抑制神经细胞凋亡及退行性改变。同时,EGCG可明显抑制p75NTR通路,降低其剪切产物p75ICD表达及JNK2磷酸化水平,减少p53和cleaved-caspase 3蛋白表达,从而抑制神经细胞凋亡和改善学习记忆障碍,发挥神经保护作用。结论 EGCG通过抑制p75NTR信号通路,抑制神经细胞凋亡,改善学习记忆障碍。

Aim To investigate whether EGCG treat-ment ameliorates cognitive deficits in APP/PS1 trans-genic mice and, whether it has the ameliorating effect of p75 NTR signaling to neuronal apoptosis in the hippo-campus of APP/PS1 mice. Methods Morris water maze test and locomotivity test were used to predict be-havioral changes; further TUNEL staining and Fluoro-Jade B staining were applied to confirm the neuronal apoptosis and neuronal degeneration;Western blot was employed to detect protein expression levels of p75 NTR signaling in the hippocampus of APP/PS1 mice. Re-sults EGCG treatment dramatically ameliorated thecognitive impairments, and inhibited the neuronal ap-optosis in the APP/PS1 mice. Moreover, EGCG treat-ment dramatically inhibited the p75 NTR signaling by de-creasing the p75ICD expression, JNK2 phosphorylation, and cleaved-caspase 3 expression. Conclusion EGCG treatment dramatically ameliorates the cognitive impairments, and inhibits the neuronal apoptosis by in-hibiting the p75NTR signaling.