Cell-permeable Peptide Antioxidants Targeted to Inner Mitochondrial Membrane inhibit Mitochondrial Swelling, Oxidative Cell Death, and Reperfusion Injury*
By Kesheng Zhao, Guo‐Min Zhao, Dunli Wu, Y. Soong, A. Birk, P. Schiller, H. Szeto. Journal of Biological Chemistry, 2004
753 citations recorded by the source corpus.
Reactive oxygen species (ROS) play a key role in promoting mitochondrial cytochrome c release and induction of apoptosis. ROS induce dissociation of cytochrome c from cardiolipin on the inner mitochondrial membrane (IMM), and cytochrome c may then be released via mitochondrial permeability transition (MPT)-dependent or MPT-independent mechanisms. We have developed peptide antioxidants that target the IMM, and we used them to investigate the role of ROS and MPT in cell death caused by t-butylhydroperoxide (tBHP) and 3-nitropropionic acid (3NP). The structural motif of these peptides centers on alternating aromatic and basic amino acid residues, with dimethyltyrosine providing scavenging properties. These peptide antioxidants are cell-permeable and concentrate 1000-fold in the IMM. They potently reduced intracellular ROS and cell death caused by tBHP in neuronal N2A cells (EC50 in nm range). They also decreased mitochondrial ROS production, inhibited MPT and swelling, and prevented cytochrome c release induced by Ca2+ in isolated mitochondria. In addition, they inhibited 3NP-induced MPT in isolated mitochondria and prevented mitochondrial depolarization in cells treated with 3NP. ROS and MPT have been implicated in myocardial stunning associated with reperfusion in ischemic hearts, and these peptide antioxidants potently improved contractile force in an ex vivo heart model. It is noteworthy that peptide analogs without dimethyltyrosine did not inhibit mitochondrial ROS generation or swelling and failed to prevent myocardial stunning. These results clearly demonstrate that overproduction of ROS underlies the cellular toxicity of tBHP and 3NP, and ROS mediate cytochrome c release via MPT. These IMM-targeted antioxidants may be very beneficial in the treatment of aging and diseases associated with oxidative stress.
Subfields: Molecular Biology
View Paper: https://www.semanticscholar.org/paper/dca4c297265d2d1fe551c64e67cdcc0d23cd727b
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Citations in the corpus
- Mitochondrial Dysfunction in Diabetes: From Molecular Mechanisms to Functional Significance and Therapeutic Opportunities (2010, positive): “Peptides containing tyrosine residues have been found effectively to scavenge oxygen radicals and peroxynitrite and to inhibit lipid peroxidation (304, 349).”
- Cardiac Metabolism and Its Interactions with Contraction, Growth, and Survival of the Cardiomyocte (2013, background): “Finally, Szeto–Schiller peptides have shown cardiac protection in guinea pig hearts subjected to ischemia–reperfusion injury and mouse models of hypertrophy and failure, in part, by reducing oxidative stress.(179,180) So far, clinical studies using such a strategy are rather limited.”