Cytochrome c release into cytosol with subsequent caspase activation during warm ischemia in rat liver.
Apoptosis plays an important role in liver ischemia and reperfusion (I/R) injury. However, the molecular basis of apoptosis in I/R injury is poorly understood. The aims of this study were to ascertain when and how apoptotic signal transduction occurs in I/R injury. The apoptotic pathway in rats undergoing 90 min of warm ischemia with reperfusion was compared with that of rats undergoing prolonged ischemia alone. During ischemia, mitochondrial cytochrome c was released into the cytosol in a time-dependent manner in hepatocytes and sinusoidal endothelial cells, and caspase-3 and an inhibitor of caspase-activated DNase were cleaved. However, apoptotic manifestation and DNA fragmentation were not observed. After reperfusion, nuclear condensation, cells positive for terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling, and DNA fragmentation were observed and caspase-8 and Bid cleavage occurred. In contrast, prolonged ischemia alone induced necrosis rather than apoptosis. In summary, our results show that release of mitochondrial cytochrome c and caspase activation proceed during ischemia, although apoptosis is manifested after reperfusion.
Soeda
J
J
First Department of Surgery, Research Center on Aging and Adaptation, Shinshu University School of Medicine, Nagano 390-8621, Japan.
Miyagawa
S
S
Sano
K
K
Masumoto
J
J
Taniguchi
S
S
Kawasaki
S
S
D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D051023:BH3 Interacting Domain Death Agonist Protein; D002352:Carrier Proteins / Q000378:metabolism; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D002458:Cell Fractionation; D003574:Cytochrome c Group / Q000378:metabolism*; D003593:Cytoplasm / Q000737:chemistry*; D003576:Electron Transport Complex IV / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D015151:Immunoblotting; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008928:Mitochondria / Q000737:chemistry / Q000201:enzymology; D011506:Proteins / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000378:metabolism* / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; D051023:BH3 Interacting Domain Death Agonist Protein; C494816:Bid protein, rat; D002352:Carrier Proteins; D061945:Caspase Inhibitors; D003574:Cytochrome c Group; D004791:Enzyme Inhibitors; D011506:Proteins; D014409:Tumor Necrosis Factor-alpha; C109664:caspase-activated DNase inhibitor; D003576:Electron Transport Complex IV; D020169:Caspases