Garrison Institute on Aging, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
Garrison Institute on Aging, South West Campus, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
J Alzheimers Dis. 2018;62(4):1549-1565. doi: 10.3233/JAD-170988.
The purpose of our study was to determine the synergistic protective effects of mitochondria-targeted antioxidant SS31 and mitochondria division inhibitor 1 (Mdivi1) in Alzheimer's disease (AD). Using biochemical methods, we assessed mitochondrial function by measuring the levels of hydrogen peroxide, lipid peroxidation, cytochrome c oxidase activity, mitochondrial ATP, and GTPase Drp1 enzymatic activity in mutant AβPP cells. Using biochemical methods, we also measured cell survival and apoptotic cell death. Amyloid-β (Aβ) levels were measured using sandwich ELISA, and using real-time quantitative RT-PCR, we assessed mtDNA (mtDNA) copy number in relation to nuclear DNA (nDNA) in all groups of cells. We found significantly reduced levels of Aβ40 and Aβ42 in mutant AβPP cells treated with SS31, Mdivi1, and SS31+Mdivi1, and the reduction of Aβ42 levels were much higher in SS31+Mdivi1 treated cells than individual treatments of SS31 and Mdivi1. The levels of mtDNA copy number and cell survival were significantly increased in SS31, Mdivi1, and SS31+Mdivi1 treated mutant AβPP cells; however, the increased levels of mtDNA copy number and cell survival were much higher in SS31+Mdivi1 treated cells than individual treatments of SS31 and Mdivi1. Mitochondrial dysfunction is significantly reduced in SS31, Mdivi1, and SS31+Mdivi1 treated mutant AβPP cells; however, the reduction is much higher in cells treated with both SS31+Mdvi1. Similarly, GTPase Drp1 activity is reduced in all treatments, but reduced much higher in SS31+Mdivi1 treated cells. These observations strongly suggest that combined treatment of SS31+Mdivi1 is effective than individual treatments of SS31 and Mdivi1. Therefore, we propose that combined treatment of SS31+Mdivi1 is a better therapeutic strategy for AD. Ours is the first study to investigate combined treatment of mitochondria-targeted antioxidant SS31 and mitochondrial division inhibitor 1 in AD neurons.
我们的研究目的是确定靶向线粒体的抗氧化剂 SS31 和线粒体分裂抑制剂 1（Mdivi1）在阿尔茨海默病（AD）中的协同保护作用。我们使用生化方法通过测量突变型 AβPP 细胞中过氧化氢、脂质过氧化、细胞色素 c 氧化酶活性、线粒体 ATP 和 GTPase Drp1 酶活性来评估线粒体功能。我们还使用生化方法测量细胞存活和凋亡细胞死亡。使用夹心 ELISA 测量淀粉样蛋白-β（Aβ）水平，并使用实时定量 RT-PCR 评估所有细胞组中线粒体 DNA（mtDNA）与核 DNA（nDNA）的拷贝数。我们发现，在用 SS31、Mdivi1 和 SS31+Mdivi1 处理的突变型 AβPP 细胞中，Aβ40 和 Aβ42 的水平显著降低，在用 SS31+Mdivi1 处理的细胞中，Aβ42 水平的降低比 SS31 和 Mdivi1 的单独处理高得多。在用 SS31、Mdivi1 和 SS31+Mdivi1 处理的突变型 AβPP 细胞中，mtDNA 拷贝数和细胞存活率显著增加；然而，在用 SS31+Mdivi1 处理的细胞中，mtDNA 拷贝数和细胞存活率的增加比 SS31 和 Mdivi1 的单独处理高得多。在用 SS31、Mdivi1 和 SS31+Mdivi1 处理的突变型 AβPP 细胞中，线粒体功能障碍显著降低；然而，在 SS31+Mdvi1 处理的细胞中，这种降低幅度要高得多。同样，在用所有处理方法处理后，GTPase Drp1 活性降低，但在用 SS31+Mdivi1 处理的细胞中降低幅度更大。这些观察结果强烈表明，SS31+Mdivi1 的联合治疗比 SS31 和 Mdivi1 的单独治疗更有效。因此，我们提出 SS31+Mdivi1 的联合治疗是 AD 的一种更好的治疗策略。我们的研究是首次探讨在 AD 神经元中联合应用靶向线粒体的抗氧化剂 SS31 和线粒体分裂抑制剂 1 的治疗方法。
