Inhibition of cytochrome c release by 10-N-nonyl acridine orange, a cardiolipin-specific dye, during myocardial ischemia-reperfusion in the rat.
The release of cytochrome c from the mitochondria to the cytosol is a critical step for downstream caspase-mediated apoptotic signal transduction in ischemia-reperfusion (I/R)-induced myocardial tissue injury. 10-N-nonyl acridine orange (NAO), a cardiolipin-specific dye, has been shown to inhibit Bid-mediated cytochrome c release from isolated mitochondria in vitro; however, the possible protective effects of NAO and the mechanisms underlying the protection from myocardial I/R-induced tissue injury in a rat model are unknown. Male Sprague-Dawley rats were subjected to a 30-min coronary arterial occlusion followed by reperfusion. All rats received either vehicle or NAO (100 microg/kg iv) 10 min before the occlusion. The infarct size in the heart at 24 h after reperfusion was significantly reduced in NAO-treated rats compared with vehicle-treated rats. NAO treatment significantly reduced the cytosolic cytochrome c contents and caspase-9 activity in the ischemic region but did not affect caspase-8 activity. Furthermore, NAO treatment markedly suppressed the translocation of truncated Bid, a proapoptotic Bcl-2 family member, to the mitochondrial fraction. NAO also suppressed the mitochondrial swelling and oxygen uptake stimulated by calcium overload. The results suggest that NAO possesses protective effects against myocardial I/R injury, which may be due to the suppression of cytochrome c release through blockade of truncated Bid translocation to mitochondria and inhibition of the opening of mitochondrial permeability transition pores.
Zhang
Guo-Xing
GX
Department of Physiology II, Nara Medical University, Nara, Japan. gxzhang@naramed-u.ac.jp
Kimura
Shoji
S
Murao
Koji
K
Obata
Koji
K
Matsuyoshi
Hiroko
H
Takaki
Miyako
M
D000609:Aminoacridines / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D051023:BH3 Interacting Domain Death Agonist Protein / Q000378:metabolism; D002308:Cardiolipins / Q000378:metabolism*; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045304:Cytochromes c / Q000037:antagonists & inhibitors* / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004195:Disease Models, Animal; D005456:Fluorescent Dyes / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D009203:Myocardial Infarction / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000473:pathology / Q000517:prevention & control*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D000609:Aminoacridines; D051023:BH3 Interacting Domain Death Agonist Protein; C494816:Bid protein, rat; D002308:Cardiolipins; D005456:Fluorescent Dyes; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; C041691:10-N-nonylacridinium orange; D045304:Cytochromes c; D053181:Caspase 8; D053453:Caspase 9