Detection of higher-order 50- and 10-kbp DNA fragments before apoptotic internucleosomal cleavage after transient cerebral ischemia.
DNA fragments of 50 and 10 kbp were found in ischemic brain in adult rats following two-vessel occlusion or in neonates following hypoxia-ischemia. These higher-order fragments were detected before any laddered oligonucleosomal DNA fragmentation characteristic of apoptosis. Both the 50- and 10-kbp fragments were also detected during necrosis produced by decapitation, but these led to smeared smaller fragments, not laddered patterns. End-group analysis showed the presence of both 3'-OH and 5'-OH ends in both the 50- and 10-kbp fragments but the predominance of 3'-OH ends in the laddered fragments. A higher proportion of 5'-OH to 3'-OH ends was found in the 10-kbp fragment compared to the larger 50-kbp fragment, suggesting a selective degradation of the 50-kbp DNA fragment to the laddered oligonucleosomal patterns. Overall, the mode of DNA fragmentation appeared different from that described in classic apoptosis of thymocytes.
MacManus
J P
JP
Institute for Biological Sciences, National Research Council of Canada, Montreal Road Laboratories, Ottawa, Canada.
Rasquinha
I
I
Tuor
U
U
Preston
E
E
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000502:physiology*; D001921:Brain / Q000473:pathology; D053938:DNA Fragmentation; D003655:Decerebrate State; D004587:Electrophoresis, Agar Gel; D016521:Electrophoresis, Gel, Pulsed-Field; D000860:Hypoxia / Q000150:complications; D002546:Ischemic Attack, Transient / Q000150:complications / Q000235:genetics* / Q000473:pathology*; D008297:Male; D009336:Necrosis; D009707:Nucleosomes / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar
D009707:Nucleosomes