title: Protection of peroxiredoxin II on oxidative stress-induced cardiomyocyte death and apoptosis.
abstract: Peroxiredoxin II, a cytosolic isoform of the antioxidant enzyme family, has been implicated in cancer-associated cell death and apoptosis, but its functional role in the heart remains to be elucidated. Interestingly, the expression levels of peroxiredoxin II were decreased in mouse hearts upon ischemia-reperfusion, while they were elevated in two genetically modified hyperdynamic hearts with phospholamban ablation or protein phosphatase 1 inhibitor 1 overexpression. To delineate the functional significance of altered peroxiredoxin II expression, adenoviruses encoding sense or antisense peroxiredoxin II were generated; cardiomyocytes were infected, and then subjected to H(2)O(2) treatment to mimic oxidative stress-induced cell death and apoptosis. H(2)O(2) stimulation resulted in a significant decrease of endogenous peroxiredoxin II expression, along with reduced cell viability in control cells. However, overexpression of peroxiredoxin II significantly protected from H(2)O(2)-induced apoptosis and necrosis, while downregulation of this enzyme promoted the detrimental effects of oxidative stress in cardiomyocytes. The beneficial effects of peroxiredoxin II were associated with increased Bcl-2 expression, decreased expression of Bax and attenuated activity of caspases 3, 9 and 12. Furthermore, there were no significant alterations in the expression levels of the other five isoforms of peroxiredoxin, as well as active catalase or glutathione peroxidase-1 after ischemia-reperfusion or H(2)O(2) treatment. These findings suggest that peroxiredoxin II may be a unique antioxidant in the cardiac system and may represent a potential target for cardiac protection from oxidative stress-induced injury.
authors.affiliation: Dept. of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267-0575, USA.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhao
authors.forename: Guo-Chang
authors.initials: GC
authors.lastname: Fan
authors.forename: Zhi-Guo
authors.initials: ZG
authors.lastname: Zhang
authors.forename: Arun
authors.initials: A
authors.lastname: Bandyopadhyay
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Zhou
authors.forename: Evangelia G
authors.initials: EG
authors.lastname: Kranias
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western; D053454:Caspase 12 / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D018014:Gene Transfer Techniques; D005979:Glutathione Peroxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000633:toxicity; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D051379:Mice; D015428:Myocardial Reperfusion Injury / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism*; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress / Q000502:physiology*; D054464:Peroxiredoxins / Q000235:genetics / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000975:Antioxidants; D016877:Oxidants; D019253:Proto-Oncogene Proteins c-bcl-2; D017392:Thiobarbituric Acid Reactive Substances; D051028:bcl-2-Associated X Protein; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D054464:Peroxiredoxins; D002374:Catalase; D005979:Glutathione Peroxidase; D053454:Caspase 12; D053148:Caspase 3; D053453:Caspase 9