Zhang Chen, Zhou Yue, Yang Guo-Yuan, Li Song
Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong UniversityChina.
Department of Bioengineering, University of CaliforniaLos Angeles, USA.
Am J Transl Res. 2017 Dec 15;9(12):5518-5527. eCollection 2017.
Most degenerative diseases are caused by free radicals. Antioxidin-RL peptide is a free radical scavenger found in the skin of plateau frog , which is more stable than vitamin C as it resists light-induced degradation. However, whether and how antioxidin-RL protects cells from oxidative stress was not clear. Here we addressed this issue, and in addition, we designed a series of antioxidin cognates by adding tyrosine residues to enhance free radical-binding capability. We performed free radical-clearing assays in solution to screen the mutants, and found a mutant antioxidin-2 that was as stable as antioxidin-RL and cleared free radical faster. By using PC-12 cells as a model, we demonstrated that both antioxidin-2 and antioxidin-RL inhibited the accumulation of intracellular free radicals triggered by HO, reduced mitochondria membrane potential dissipation, maintained mitochondrial morphology, and decreased the expression of dynamin-related protein-1 in mitochondria, with antioxidin-RL more effective. Antioxidin-RL also attenuated the changes in SOD1 and GPx1 expression induced by HO. These findings provide insight into the anti-oxidative mechanisms of antioxidin-RL and its derivatives, which will provide rational basis for the development of more effective antioxidants to cure diseases.
大多数退行性疾病是由自由基引起的。抗氧化肽RL是在高原林蛙皮肤中发现的一种自由基清除剂，它比维生素C更稳定，因为它能抵抗光诱导的降解。然而，抗氧化肽RL是否以及如何保护细胞免受氧化应激尚不清楚。在此，我们解决了这个问题，此外，我们通过添加酪氨酸残基设计了一系列抗氧化肽类似物，以增强自由基结合能力。我们在溶液中进行自由基清除试验以筛选突变体，发现了一种与抗氧化肽RL一样稳定且清除自由基更快的突变体抗氧化肽-2。以PC-12细胞为模型，我们证明抗氧化肽-2和抗氧化肽RL均能抑制过氧化氢引发的细胞内自由基积累，减少线粒体膜电位耗散，维持线粒体形态，并降低线粒体中动力相关蛋白-1的表达，其中抗氧化肽RL更有效。抗氧化肽RL还减弱了过氧化氢诱导的超氧化物歧化酶1和谷胱甘肽过氧化物酶1表达的变化。这些发现为抗氧化肽RL及其衍生物的抗氧化机制提供了见解，这将为开发更有效的抗氧化剂治疗疾病提供合理依据。
