title: Apoptotic cell death progression after photothrombotic focal cerebral ischaemia: effects of the lipophilic iron chelator 2,2'-dipyridyl.
abstract: Two different forms of cell death have been distinguished morphologically following cerebral ischaemia: necrotic and apoptotic cell death. The aim of this study was to investigate the contribution of apoptosis to ischaemic damage by carefully depicting the temporal and spatial neuronal death following focal ischaemia. For this purpose, rats were subjected to chemical photothrombosis, and histological and biochemical analyses were performed over a period of 24 h after the onset of ischaemia. In addition, the effects of the lipophilic antioxidant iron chelator 2,2'-dipyridyl (DP) were evaluated 24 h after photothrombosis when the lesion volume was maximal. Our results showed two separate waves of neuronal death. In the first wave, shrunken dark neurons were massively present as early as 2 h after photothrombosis in the infarct core. From this initial neuronal abnormal population, progressive and time-dependent changes of both necrotic and apoptotic cell death were observed, leading to ghost neurons and apoptotic bodies after 24 h. The extension of the lesion coincided with a second wave of cell death. Massive and rapid neuronal loss occurred at the infarct border, which appeared as a sharply demarcated pale region. Procaspase and poly(ADP-ribose) polymerase-1 (PARP-1) cleavages were also detected in the infarct core and surrounding damaged tissue. DP treatment markedly blocked the enlargement of the lesion, the infarct border being rescued from infarction. Furthermore, a large decrease of apoptotic bodies was associated with a significant drop of caspase and PARP-1 cleavages, suggesting that the protective effect of DP closely correlates with limitation of apoptosis expansion.
authors.affiliation: Laboratoire de Pharmacodynamie et Physiologie Pharmaceutique (L3P), Faculté de Pharmacie, BP 87900, 21079 Dijon Cedex, France.
authors.forename: Michaël
authors.initials: M
authors.lastname: Van Hoecke
authors.forename: Anne
authors.initials: A
authors.lastname: Prigent-Tessier
authors.forename: Nathalie
authors.initials: N
authors.lastname: Bertrand
authors.forename: Laurent
authors.initials: L
authors.lastname: Prevotat
authors.forename: Christine
authors.initials: C
authors.lastname: Marie
authors.forename: Alain
authors.initials: A
authors.lastname: Beley
mesh_terms: D015082:2,2'-Dipyridyl / Q000627:therapeutic use*; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western / Q000379:methods; D001923:Brain Chemistry / Q000502:physiology / Q000528:radiation effects; D020520:Brain Infarction / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control; D002545:Brain Ischemia / Q000473:pathology* / Q000503:physiopathology; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D002614:Chelating Agents / Q000627:therapeutic use*; D053938:DNA Fragmentation / Q000187:drug effects / Q000502:physiology; D004195:Disease Models, Animal; D005455:Fluorescent Antibody Technique / Q000379:methods; D007839:Functional Laterality / Q000187:drug effects / Q000502:physiology; D020767:Intracranial Thrombosis / Q000473:pathology / Q000503:physiopathology; D008297:Male; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D002614:Chelating Agents; D015082:2,2'-Dipyridyl; C499322:Parp1 protein, rat; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; C505410:Casp3 protein, rat; C506435:Casp9 protein, rat; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases