Institute of Neuroscience, School of Basic Medicine, Chongqing Medical University, Chongqing, 400016, China.
Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China; Institute of Life Sciences, Chongqing Medical University, Chongqing, 400016, China; Liggins Institute, University of Auckland, Auckland, 1023, New Zealand.
Exp Cell Res. 2020 Nov 1;396(1):112266. doi: 10.1016/j.yexcr.2020.112266. Epub 2020 Sep 6.
The aggregation of β-amyloid (Aβ) peptide in Alzheimer's disease (AD) is characterized by mitochondrial dysfunction and mitophagy impairment. Mitophagy is a homeostatic mechanism by which autophagy selectively eliminates damaged mitochondria. Valinomycin is a respiratory chain inhibitor that activates mitophagy via the PINK1/Parkin signaling pathway. However, the mechanism underlying the association between mitophagy and valinomycin in Aβ formation has not been explored. Here, we demonstrate that genetically modified (N2a/APP695swe) cells overexpressing a mutant amyloid precursor protein (APP) serve as an in vitro model of AD for studying mitophagy and ATP-related metabolomics. Our results prove that valinomycin induced a time-dependent increase in the mitophagy activation of N2a/APP695swe cells as indicated by increased levels of PINK1, Parkin, and LC3II as well as increased the colocalization of Parkin-Tom20 and fewer mitochondria (indicated by decreased Tom20 levels). Valinomycin significantly decreased Aβ and Aβ levels after 3 h of treatment. ATP levels and ATP-related metabolites were significantly increased at this time. Our findings suggest that the elimination of impaired mitochondria via valinomycin-induced mitophagy ameliorates AD by decreasing Aβ and improving ATP levels.
β-淀粉样蛋白（Aβ）肽在阿尔茨海默病（AD）中的聚集特征是线粒体功能障碍和自噬体吞噬功能障碍。自噬体吞噬是一种通过自噬选择性消除受损线粒体的体内平衡机制。缬氨霉素是一种呼吸链抑制剂，通过 PINK1/Parkin 信号通路激活自噬体吞噬。然而，自噬体吞噬与缬氨霉素在 Aβ 形成中的关联机制尚未被探索。在这里，我们证明了过表达突变淀粉样前体蛋白（APP）的基因修饰（N2a/APP695swe）细胞作为研究自噬体吞噬和与 ATP 相关的代谢组学的 AD 体外模型。我们的结果证明，缬氨霉素诱导 N2a/APP695swe 细胞的自噬体吞噬激活呈时间依赖性增加，如 PINK1、Parkin 和 LC3II 水平增加以及 Parkin-Tom20 共定位增加和线粒体减少（Tom20 水平降低）。缬氨霉素在治疗 3 小时后显著降低 Aβ 和 Aβ 水平。此时 ATP 水平和与 ATP 相关的代谢物显著增加。我们的发现表明，通过缬氨霉素诱导的自噬体吞噬消除受损线粒体可通过降低 Aβ 和改善 ATP 水平来改善 AD。
