开心散对Aβ_(25-35)诱导损伤SH-N-K神经细胞的保护作用及机制

The protective effect and mechanism of "Kai Xing San" on damaged SH-N-K neural cells induced by Aβ_(25-35)

目的观察开心散对神经毒性物质β-淀粉样肽(Aβ25-35)诱导损伤的SK-N-SH细胞的保护作用。方法用Aβ25-35处理人神经母细胞瘤细胞(SK-N-SH细胞),模拟阿尔茨海默病(AD)病人脑内神经元病理损伤,并以含开心散(KXS)药物血清拮抗其作用。以MTT法测定细胞存活率,酶反应法检测细胞内超氧化物歧化酶SOD水平变化,流式细胞技术检测细胞凋亡率。逆转录聚合酶链式反应(RT-PCR)检测淀粉样肽蛋白前体(APP)基因、Aβ降解酶NEP基因的表达情况,Westernblots法检测APP蛋白表达。结果试验显示暴露Aβ25-35后培养SK-N-SH细胞存活率明显下降,凋亡细胞比例增加。而含开心散药物血清处理能显著提高Aβ25-35损伤细胞的存活率,减少细胞凋亡率,同时提高细胞内SOD的活力(P<0.01)。RT-PCR结果显示开心散可降低Aβ代谢相关的APP基因的表达并提高NEP基因的表达,APP蛋白表达显著减少。结论AD病理相关的Aβ25-35能造成神经元细胞损伤死亡,开心散对毒性Aβ25-35诱导的神经细胞损伤具有一定保护作用,其作用机制可能与开心散能增加抗氧化酶SOD活力,同时下调内源性APP基因表达,上调NEP基因表达,减少内源Aβ产生,从而抑制细胞死亡有关。

Objective To investigate the protective effect of Kai Xin San （KXS） on SH-N-K neural cells induced by neurotoxic amyloid peptide （Aβ25-35）. Methods Treated human neuroblastema SK-N-SH cells with Aβ25-35, simulating the pathologic damage in brain of patients with Alzheimer＇ s disease, and antagonized the effect by adding KXS, Cell survival rate and apoptosis rate were measured by MTT assay and flow cytometry, intraceilular superoxide dismutase （SOD） level were tested by enzymatic method. The expression of amyloid precursor protein （APP） gene and Aβ degradating enzyme neprilysin （NEP） gene were detected by RT-PCR and APP protein expression detected by Western-blotting. Results The experiment showed that survival ratio of SK-N-SH ceils were significantly decreased after exposure on Aβ25-35, and the treatment of KXS significantly increased survival ratio and decreased apoptosis ratio of Aβ ,damaged SK-N-SH cells and increased cellular SOD activity （ P 〈 0.01） .RT-PCR result indicated that the KXS might related to the Aβ metabolism gene, decreased APP gene expression and APP protein expression and improved NEP gene expression significantly. Conclusion Aβ25-35, related to the pathology of Alzheimer＇s disease, can result in the damage and death of neuron cells, and KXS may exert neuroprotective effect on SH-N-K neural cells induced by neurotoxic Aβ which might associated with that KXS can increase SOD activity, and upregulate APP and downregulate NEP gene expression, so decrease Aβ production, then inhibit cell death.