title: Temporal profile of cytochrome c and caspase-3 immunoreactivities and TUNEL staining after permanent middle cerebral artery occlusion in rats.
abstract: Although apoptotic pathways play important roles in ischemic neuronal injury, exact mechanism of apoptotic enzyme cascade has not been fully studied. Immunohistochemical stainings for cytochrome c and caspase-3, and histochemical staining for a terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP-biotin nick end-labeling method (TUNEL) were examined in a rat model of permanent middle cerebral artery (MCA) occlusion. Cytochrome c was strongly induced in neurons of the ischemic penumbra from 3 h after MCA occlusion, and caspase-3 began to be induced in the same area from 3 h with a peak at 8 h. Neuronal cells in MCA area became TUNEL positive at delayed time, reaching a peak at 24 h. Thus, the peak of induction of cytochrome c preceded that of caspase-3, and these two peaks were also precedence of the peak of DNA-fragmentation. Western blot analysis showed cytosolic expression of cytochrome c from mitochondria. This study demonstrated 1. Rapid release of cytochrome c from mitochondria to the cytosol, mainly in neurons of the cortex at 3 h after ischemia. 2. Subsequent peaks of caspase-3 and TUNEL in this order. These temporal profiles suggest a serial cascadic activation of apoptotic pathways in neuronal death after permanent MCA occlusion of rats.
authors.affiliation: Department of Neurology, Okayama University Medical School, Japan.
authors.forename: C
authors.initials: C
authors.lastname: Sasaki
authors.forename: H
authors.initials: H
authors.lastname: Kitagawa
authors.forename: W R
authors.initials: WR
authors.lastname: Zhang
authors.forename: H
authors.initials: H
authors.lastname: Warita
authors.forename: K
authors.initials: K
authors.lastname: Sakai
authors.forename: K
authors.initials: K
authors.lastname: Abe
mesh_terms: D000818:Animals; D001157:Arterial Occlusive Diseases / Q000378:metabolism*; D015153:Blotting, Western; D002545:Brain Ischemia / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D002536:Cerebral Arteries; D003574:Cytochrome c Group / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013194:Staining and Labeling; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D003574:Cytochrome c Group; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases