Integrins inhibit lps-induced dna strand breakage in cultured lung
endothelial cells.
Hoyt, Dale G., Robert J. Mannix, Mary E. Gerritsen, Simon A. Watkins,
John S. Lazo, and Bruce R. Pitt.
Department of Pharmacology, University of Pittsburgh School of
Medicine, Pittsburgh, PA 15261 and Bayer Research Center, Bayer
Corporation, 400 Morgan Lane, West Haven, CT 06516-4175
APStracts 2:0220L, 1995.
Integrins Inhibit LPS-induced DNA Strand Breakage in Cultured Lung
Endothelial Cells. Dale G. Hoyt, Robert J. Mannix, Mary E. Gerritsen,
Simon A. Watkins, John S. Lazo and Bruce R. Pitt. American Journal of
Physiology (Lung Cell and Molecular Physiology) xx: xxx-xxx, 1995.
Collagen inhibits acute DNA strand breakage and apoptosis in sheep
pulmonary artery endothelial cells (SPAEC) treated with
lipopolysaccharide (LPS). Here we tested the ability of major
basement membrane components, type IV collagen, laminin and
fibronectin, and integrin ligands and anti-integrin antibodies to
inhibit DNA breakage caused by LPS in SPAEC and BALB/c murine lung
endothelial cells (MLEC). In situ labelling of DNA strand breaks with
terminal deoxynucleotidyl transferase revealed similar DNA breakage
in attached SPAEC and MLEC within 2 h after incubation with 1 [mu]g
LPS/ml. Acute DNA strand breakage was reduced in cells plated on
gelatin, type IV collagen, laminin, cellular fibronectin or plasma
fibronectin. DNA breakage was also suppressed by plating cells on
surfaces coated with the integrin ligand hexapeptide, GRGDSP (40
[mu]g/cm2), but not with GRADSP. LPS-induced DNA strand breakage was
inhibited in MLEC plated on surfaces coated with antibodies to murine
[alpha]5, [beta]1 or [beta]3 integrin subunits. Addition of anti
-integrin antibodies, but not GRGDSP, to the medium above cell
monolayers inhibited strand breakage. Despite similar acute DNA
breakage, MLEC exhibited less detachment and apoptosis than SPAEC,
consistent with a difference in the sensing or processing systems for
apoptosis in these two cell types. These results demonstrate that
extracellular matrices and integrin activation can inhibit the
genotoxicity of LPS.
Received 22 September 1995; accepted in final form 30 November
1995.
APS Manuscript Number L281-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 12 December 95