S. Kojima et al., LIPOPOLYSACCHARIDE INHIBITS ACTIVATION OF LATENT TRANSFORMING GROWTH-FACTOR-BETA IN BOVINE ENDOTHELIAL-CELLS, Journal of cellular physiology, 163(1), 1995, pp. 210-219
The activation of latent transforming growth factor-beta (TGF-beta) by
vascular endothelial cells (ECs) is regulated by cellular plasminogen
activator (PA)/plasmin, transglutaminase (TGase), and latent TGF-beta
levels. Because lipopolysaccharide (LPS) has been reported to reduce
EC surface plasmin levels by increasing the production of the inhibito
r of PA, PA inhibitor-1 (PAI-1), we have tested whether LPS might supp
ress latent TGF-beta activation in ECs using two different systems, na
mely, bovine aortic ECs (BAECs) cocultured with smooth muscle cells (S
MCs) and BAECs treated with retinol. BAECs were either cocultured with
SMCs after treatment with 15 ng/ml LPS or were treated with 2 mu M re
tinol and/or 10 ng/ml LPS, and the expression of PA, surface plasmin,
TGase, and the amounts of active and latent TGF-beta secreted into the
culture medium were measured. The downregulation of surface PA/plasmi
n levels with LPS was accompanied by a profound decline of both TGase
and latent TGF-beta expression as well as the suppression of surface a
ctivation of latent TGF-beta. The effect was dependent on the concentr
ation of LPS and on treatment time. The formation of TGF-beta did not
occur in cells maintained in LPS-contaminated culture medium. (C) 1995
Wiley-Liss, Inc.