title: Cystatin C expression is increased in the hippocampus following photothrombotic stroke in rat.
abstract: Stroke is a major cause of epilepsy, but the molecular mechanisms underlying post-stroke epileptogenesis are unknown. The expression of cystatin C, a cysteine protease inhibitor, is increased in the hippocampus during status epilepticus (SE)-induced epileptogenesis, and regulates both cell death and birth. To test the hypothesis that increased cystatin C expression represents a common molecular alteration induced by epileptogenic brain insults, we investigated the time course, cellular localization, and association of cystatin C expression with neuronal damage during post-stroke epileptogenesis. Stroke was induced with photothrombosis, which leads to epilepsy in approximately 20-30% of rats. Cystatin C expression was increased in the CA1 area of the hippocampus 4 days after photothrombosis, when the diameter of the lesion was the largest. Double-labeling and confocal analysis indicated that cystatin C was expressed in astrocytes and microglia. Unlike after SE, cystatin C expression did not change in the dentate gyrus. Also, increased cystatin C expression was not associated with neurodegeneration, which was demonstrated as an absence of Fluoro Jade B-positive cells in adjacent sections. The present study provides evidence that cystatin C may be involved in cellular alterations that occur after an epileptogenic insult, not only after SE but also after photothrombotic stroke.
authors.affiliation: A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland.
authors.forename: Terhi J
authors.initials: TJ
authors.lastname: Pirttilä
authors.forename: Asla
authors.initials: A
authors.lastname: Pitkänen
mesh_terms: D000818:Animals; D055316:Cystatin C; D015891:Cystatins / Q000096:biosynthesis*; D005456:Fluorescent Dyes / Q000633:toxicity; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D018613:Microscopy, Confocal; D009410:Nerve Degeneration / Q000473:pathology; D009457:Neuroglia / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012395:Rose Bengal / Q000633:toxicity; D013226:Status Epilepticus / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D020521:Stroke / Q000150:complications / Q000473:pathology / Q000503:physiopathology
chemical_list: C525032:Cst3 protein, rat; D055316:Cystatin C; D015891:Cystatins; D005456:Fluorescent Dyes; D012395:Rose Bengal