Supplementation of endothelial cells with mitochondria-targeted antioxidants inhibit peroxide-induced mitochondrial iron uptake, oxidative damage, and apoptosis. J Biol Chem 2004 Sep 03;279(36):37575-87
Date
06/29/2004Pubmed ID
15220329DOI
10.1074/jbc.M404003200Scopus ID
2-s2.0-4444315545 (requires institutional sign-in at Scopus site) 217 CitationsAbstract
The mitochondria-targeted drugs mitoquinone (Mito-Q) and mitovitamin E (MitoVit-E) are a new class of antioxidants containing the triphenylphosphonium cation moiety that facilitates drug accumulation in mitochondria. In this study, Mito-Q (ubiquinone attached to a triphenylphosphonium cation) and MitoVit-E (vitamin E attached to a triphenylphosphonium cation) were used. The aim of this study was to test the hypothesis that mitochondria-targeted antioxidants inhibit peroxide-induced oxidative stress and apoptosis in bovine aortic endothelial cells (BAEC) through enhanced scavenging of mitochondrial reactive oxygen species, thereby blocking reactive oxygen species-induced transferrin receptor (TfR)-mediated iron uptake into mitochondria. Glucose/glucose oxidase-induced oxidative stress in BAECs was monitored by oxidation of dichlorodihydrofluorescein that was catalyzed by both intracellular H(2)O(2) and transferrin iron transported into cells. Pretreatment of BAECs with Mito-Q (1 microM) and MitoVit-E (1 microM) but not untargeted antioxidants (e.g. vitamin E) significantly abrogated H(2)O(2)- and lipid peroxide-induced 2',7'-dichlorofluorescein fluorescence and protein oxidation. Mitochondria-targeted antioxidants inhibit cytochrome c release, caspase-3 activation, and DNA fragmentation. Mito-Q and MitoVit-E inhibited H(2)O(2)- and lipid peroxide-induced inactivation of complex I and aconitase, TfR overexpression, and mitochondrial uptake of (55)Fe, while restoring the mitochondrial membrane potential and proteasomal activity. We conclude that Mito-Q or MitoVit-E supplementation of endothelial cells mitigates peroxide-mediated oxidant stress and maintains proteasomal function, resulting in the overall inhibition of TfR-dependent iron uptake and apoptosis.
Author List
Dhanasekaran A, Kotamraju S, Kalivendi SV, Matsunaga T, Shang T, Keszler A, Joseph J, Kalyanaraman BAuthors
Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of WisconsinAgnes Keszler PhD Research Scientist I in the Biophysics department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
Aconitate HydrataseAnimals
Antioxidants
Apoptosis
Cattle
Cells, Cultured
Electron Transport Complex I
Endothelium, Vascular
Glucose Oxidase
In Situ Nick-End Labeling
Iron
Mitochondria
Oxidative Stress
Peroxides
Receptors, Transferrin