title: F-actin disorganization in apoptotic cell death of cultured rat renal proximal tubular cells.
abstract: The mechanism of nephrotoxin-induced apoptosis was studied in rat renal proximal tubular cells (PTC) exposed to the nephrotoxin S-(1,2-dichlorovinyl)-L-cysteine (DCVC). After a 6-h incubation, DCVC caused a condensation of heterochromatin and a fragmentation of the nucleus in 84 and 16% of the cells, respectively, which is indicative of apoptosis. This was confirmed biochemically by agarose gel electrophoresis demonstrating the formation of DNA fragments with multiples of 200 bp. The antioxidant N,N'-diphenyl-p-phenylenediamine prevented neither the fragmentation of the nucleus nor the formation of DNA fragments, but it did prevent lactate dehydrogenase release and bleb formation by DCVC. Apoptosis induced by DCVC was closely associated with F-actin disorganization: every cell with a fragmented nucleus displayed completely disorganized F-actin, while cells with a normal nucleus still possessed at least some intact F-actin also induced apoptosis in PTC. Similarly, dithiothreitol, which damages F-actin in PTC, caused apoptosis of PTC. These data suggest a causal relationship between F-actin disorganization and apoptosis of PTC.
authors.affiliation: Division of Toxicology, Leiden Amsterdam Centre for Drug Research, Leiden University, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Van de Water
authors.forename: M
authors.initials: M
authors.lastname: Kruidering
authors.forename: J F
authors.initials: JF
authors.lastname: Nagelkerke
mesh_terms: D000199:Actins / Q000502:physiology*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000502:physiology*; D002118:Calcium / Q000502:physiology; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D003545:Cysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004229:Dithiothreitol / Q000494:pharmacology; D007687:Kidney Tubules, Proximal / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D008190:Lyases / Q000037:antagonists & inhibitors; D008297:Male; D010655:Phenylenediamines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000199:Actins; D000975:Antioxidants; D010655:Phenylenediamines; D003609:Dactinomycin; C039961:S-(1,2-dichlorovinyl)cysteine; D003513:Cycloheximide; C004845:N,N'-diphenyl-4-phenylenediamine; D008190:Lyases; D003545:Cysteine; D002118:Calcium; D004229:Dithiothreitol