Induction of caspase-activated deoxyribonuclease activity after focal cerebral ischemia and reperfusion.
Deoxyribonucleic acid fragmentation at nucleosomal junctions is a hallmark of neuronal apoptosis in ischemic brain injury, for which the mechanism is not fully understood. Using the in vitro cell-free apoptosis assay, the authors found that caspase-3-dependent deoxyribonuclease activity caused internucleosomal DNA fragmentation in brain-cell extracts in a rat model of transient focal ischemia. This in vitro deoxyribonuclease activity was completely inhibited by purified inhibitor of caspase-activated deoxyribonuclease protein, the specific endogenous inhibitor of caspase-activated deoxyribonuclease, or by caspase-activated deoxyribonuclease immunodepletion. The induction of the deoxyribonuclease activity was correlated with caspase-3 activation and caspase-3-mediated degradation of inhibitor of caspase-activated deoxyribonuclease. Furthermore, inhibiting caspase-3-like protease activity prevented the endogenous induction of internucleosomal DNA fragmentation in the ischemic brain. These results suggest that caspase-3-dependent caspase-activated deoxyribonuclease activity plays an important role in mediating DNA fragmentation after focal ischemia.
Luo
Yumin
Y
Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
Cao
Guodong
G
Pei
Wei
W
O'Horo
Cristine
C
Graham
Steven H
SH
Chen
Jun
J
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D051017:Apoptosis Regulatory Proteins; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D002474:Cell-Free System; D053938:DNA Fragmentation; D003851:Deoxyribonucleases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000378:metabolism; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D002546:Ischemic Attack, Transient / Q000503:physiopathology*; D008297:Male; D017072:Neostriatum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000503:physiopathology
D051017:Apoptosis Regulatory Proteins; D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D009842:Oligopeptides; D011506:Proteins; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; C109664:caspase-activated DNase inhibitor; D003851:Deoxyribonucleases; C109663:caspase-activated deoxyribonuclease; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases