Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9882167 | Archives of Biochemistry and Biophysics | 2005 | 6 Pages |
Abstract
Activation of the δ-isoform of protein kinase C (δPKC) by certain conditions of oxidative stress results in translocation of the kinase to the mitochondria leading to release of cytochrome c and the induction of apoptosis. In the current study, the effects of myocardial reperfusion-induced δPKC translocation on mitochondrial function were assessed. Mitochondria isolated from hearts that had undergone ischemia (30 min) followed by reperfusion (15 min) exhibited a significant increase in the rate of superoxide anion (O2â) generation. This was associated with the translocation of δPKC to the mitochondria within the first 5 min of reperfusion. δPKC translocation occurred exclusively during reperfusion and could be mimicked by infusion of intact hearts with H2O2 suggesting redox-dependent activation during reperfusion. Infusion of a peptide inhibitor (δV1-1) specific to the δ-isoform of PKC significantly reduced reperfusion-induced increases in mitochondrial O2â generation. Finally, the decline in mitochondrial respiratory activity evident upon prolonged reperfusion (120 min) was completely prevented by inhibition of δPKC translocation. Thus, δPKC represents a cytosolic redox-sensitive molecule that plays an important role in amplification of O2â production and subsequent declines in mitochondrial function during reperfusion.
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Authors
Eric N. Churchill, Luke I. Szweda,