title: Temporal and regional patterns of Smad activation in the rat hippocampus following global ischemia.
abstract: In this study, we examined the temporal and regional patterns of Smad activation in the rat hippocampus following global ischemia. We also examined the association between Smad activation and ischemia-induced pathology in the hippocampus. We found that 1) Smad1, -2, -3, and -5 proteins were detected in the rat hippocampus by means of western blot and immunohistochemistry; 2) after 5 min of ischemia, Smad2 and Smad3 proteins accumulated in the nuclei of pyramidal cells in the CA1 region, which is vulnerable to ischemia; 3) after 3 min of ischemia, which was non-lethal, there was no such nuclear accumulation of Smad2 and Smad3 in the CA1 region; 4) following injection of activin A, nuclear accumulation of Smad2 and Smad3 was induced not only in pyramidal cells of the CA1 region, but also in pyramidal cells of the CA3 region as well as in granule cells of the DG region; 5) activin A-induced nuclear accumulation of Smad2 and Smad3 neither caused degeneration of hippocampal neurons nor prevented degeneration induced by ischemia. These results suggest that in the hippocampus, ischemia-induced activation of Smad2 and Smad3 is associated with the response to stress but is not related to neuronal survival or death.
authors.affiliation: Department of Veterinary Anatomy, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ohraikita, Izumisano, Osaka 598-8531, Japan. Electronic address: t-nakaji@vet.osakafu-u.ac.jp.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakajima
authors.affiliation: Department of Veterinary Anatomy, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ohraikita, Izumisano, Osaka 598-8531, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yanagihara
authors.affiliation: Department of Veterinary Anatomy, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ohraikita, Izumisano, Osaka 598-8531, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Nishii
mesh_terms: D028341:Activins / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism; D016923:Cell Death; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D007276:Injections, Intraventricular; D007511:Ischemia / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015424:Reperfusion; D051785:Smad Proteins / Q000235:genetics / Q000378:metabolism*; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D014404:Tubulin / Q000378:metabolism
chemical_list: C100745:Aif1 protein, rat; D002135:Calcium-Binding Proteins; D008840:Microfilament Proteins; D051785:Smad Proteins; D014404:Tubulin; C422405:activin A; D028341:Activins
keywords: Delayed neuronal death; Global ischemia; Hippocampus; Microglia; Rat; Smad