title: Induction of caspase-3-like protease may mediate delayed neuronal death in the hippocampus after transient cerebral ischemia.
abstract: Delayed neuronal death after transient cerebral ischemia may be mediated, in part, by the induction of apoptosis-regulatory gene products. Caspase-3 is a newly characterized mammalian cysteine protease that promotes cell death during brain development, in neuronal cultures, and in other cell types under many different conditions. To determine whether caspase-3 serves to regulate neuronal death after cerebral ischemia, we have (1) cloned a cDNA encoding the rat brain caspase-3; (2) examined caspase-3 mRNA and protein expression in the brain using in situ hybridization, Northern and Western blot analyses, and double-labeled immunohistochemistry; (3) determined caspase-3-like activity in brain cell extracts; and (4) studied the effect of caspase-3 inhibition on cell survival and DNA fragmentation in the hippocampus in a rat model of transient global ischemia. At 8-72 hr after ischemia, caspase-3 mRNA and protein were induced in the hippocampus and caudate-putamen (CPu), accompanied by increased caspase-3-like protease activity. In the hippocampus, caspase-3 mRNA and protein were predominantly increased in degenerating CA1 pyramidal neurons. Proteolytic activation of the caspase-3 precursor was detected in hippocampus and CPu but not in cortex at 4-72 hr after ischemia. Double-label experiments detected DNA fragmentation in the majority of CA1 neurons and selective CPu neurons that overexpressed caspase-3. Furthermore, ventricular infusion of Z-DEVD-FMK, a caspase-3 inhibitor, decreased caspase-3 activity in the hippocampus and significantly reduced cell death and DNA fragmentation in the CA1 sector up to 7 d after ischemia. These data strongly suggest that caspase-3 activity contributes to delayed neuronal death after transient ischemia.
authors.affiliation: Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: T
authors.initials: T
authors.lastname: Nagayama
authors.forename: K
authors.initials: K
authors.lastname: Jin
authors.forename: R A
authors.initials: RA
authors.lastname: Stetler
authors.forename: R L
authors.initials: RL
authors.lastname: Zhu
authors.forename: S H
authors.initials: SH
authors.lastname: Graham
authors.forename: R P
authors.initials: RP
authors.lastname: Simon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001710:Biotin; D020170:Caspase 1; D053148:Caspase 3; D020169:Caspases; D002540:Cerebral Cortex / Q000201:enzymology; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D053938:DNA Fragmentation; D018076:DNA, Complementary; D003856:Deoxyuracil Nucleotides; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism; D002546:Ischemic Attack, Transient / Q000201:enzymology*; D008297:Male; D008969:Molecular Sequence Data; D017072:Neostriatum / Q000201:enzymology; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D009842:Oligopeptides / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling; D013379:Substrate Specificity
chemical_list: D015853:Cysteine Proteinase Inhibitors; D018076:DNA, Complementary; D003856:Deoxyuracil Nucleotides; D004792:Enzyme Precursors; D009842:Oligopeptides; D012333:RNA, Messenger; C108637:aspartyl-glutamyl-valyl-aspartal; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; C096429:L 709049; D001710:Biotin; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases; D020170:Caspase 1