阿魏酸钠对淀粉样β蛋白片段1-42引起的培养海马神经元损伤的保护作用及机制

Protective effect of sodium ferulate on Aβ_(1-42)-induced neurotoxicity in cultured hippocampal neurons

目的研究阿魏酸钠对β蛋白片段1-42所致培养海马神经元损伤的保护作用及机制。方法原代培养海马神经元,阿魏酸钠(50、100、200μmol·L-1)预处理6 h后,加入50 nmol·L-1的Aβ1-42作用72 h,MTT法测海马神经元细胞存活率,应用倒置相差显微镜和微管相关蛋白-2(MAP-2)免疫荧光染色观察神经元树突的生长,Western蛋白印迹法检测海马神经元磷酸化mTOR和p70s6K蛋白表达。结果与对照组相比,Aβ1-42引起海马神经元细胞的存活率明显降低(P<0.01),可使培养海马神经元出现明显退行性改变,表现为树突串珠样改变和突起回缩,树突总长度和末梢分支数明显减少,磷酸化的mTOR和p70s6K蛋白表达水平明显降低(P<0.01)。应用阿魏酸钠(50、100、200μmol·L-1)预处理6 h可明显对抗Aβ1-42引起的神经元损伤及蛋白表达的改变(P<0.01)。结论阿魏酸钠通过上调磷酸化的mTOR/p70s6K对抗Aβ1-42引起的海马神经元损伤。

Aim To investigate the protective effect of sodium ferulate（SF） on neurotoxieity of cultured hippocampal neurons induced by Aβ1-42. Methods The primary cultured hippocampal neurons were exposed to Aβ1-42 50 nmol · L-1 for 72 h after pretreatment with various concentrations of SF （50, 100, 200 μmol·L-1） for 6 h. Then neuronal viability was tested by MTr assay. Neuronal dendrite outgrowth was observed using phase-contrast microscope and immunostaining for the dendritic marker MAP2. The eellularextracts were prepared for Western blot of p-mTOR and pp70s6K. Results Cultured hippocampal neurons treated with preaggregated Aβ1-42 for 72 h displayed signs of degeneration, includimg the formation of varicosities and retraction of neuritis. Compared with control, Aβ1-42 treatment resulted in the decrease in total dendrite branch length and terminal branch number of hippocampal neurons, and the decrease of the survival rate of neurons, the protein levels of p-roTOR and p- p70s6K in Aβ1-42 treatment group cells were significantly decreased. This Aβ1-42-induced changes could be reversed by pretreatment with SF （50, 100,200μmol · L-1 ） for 6 h. Conclusion SF can prevent the cultured hippocampal neurons from Aβ1-42 neurotoxicity by increasing p-mTOR and p-p70s6K protein levels.