F-actin disorganization in apoptotic cell death of cultured rat
renal proximal tubular cells.
Water, Bob Van De, Marieke Kruidering, and J. Fred Nagelkerke.
Division of Toxicology, Leiden Amsterdam Centre for Drug Research,
(LACDR), Leiden University, The Netherlands
APStracts 2:0185F, 1995.
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 6 hours 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
(DPPD) prevented neither the fragmentation of the nucleus nor the
formation of DNA fragments, but it did prevent LDH-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 fibres.
Cytochalasin D which specifically disrupts F-actin also induced
apoptosis in PTC. Similarly, DTT, which damages F-actin in PTC,
caused apoptosis of PTC. These data suggest a causal relationship
between F-actin disorganization and apoptosis of PTC.
Received 23 June 1995; accepted in final form 13 October 1995.
APS Manuscript Number F201-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95