Asbestos-induced alteration of urokinase like plasminogen activator message and activity in endothelial cells.
Treadwell-MD; Mossman-BT; Barchowsky-A
FASEB J 1995 Mar; 9(4)(II):A958
Inhalation of asbestos may activate the pulmonary endothelium to promote an altered cell phenotype that participates in the development of pulmonary fibrosis. In the present study, we demonstrated that noncytotoxic concentrations of asbestos, but not a ceramic fiber, cause time dependent changes in endothelial cell morphology and phenotype. We then investigated whether these changes were associated with an increase in the expression and enzymatic activity of urokinase (uPA), a serine protease known to .be involved in tissue remodeling. Low passage porcine aortic endothelial cells were incubated with chrysotile (10 µ1g/cm2) or crocidolite asbestos (5 µ1g/cm2) or with refractory ceramic fiber 1 (RCF-I) (10 µ1g/cm2) for up to 24 hours and then assayed for steady state uPA mRNA levels by solution hybridization or uPA enzymatic activity by in situ or gel-based zymography. Eight hours of exposure to chrysotile or crocidolite caused a two- or seven-fold increase in mRNA for uPA, respectively, which was sustained for 24 hours. In situ zymography demonstrated a corresponding increase in uPA activity that was confirmed by gel zymography. In contrast, RCF-l caused neither increased uPA message levels nor enzymatic activity. These data suggest that endothelial cells respond to specific fibers by altering their morphology and assuming an activated phenotype. Fiber-specific activation of endothelial cells to express more active uPA may contribute to the tissue remodeling cascade seen following asbestos fiber deposition within the lung.
Asbestos-fibers; Pulmonary-system-disorders; Cell-alteration; Cell-morphology; Enzyme-activity; Lung-tissue; Fibrosis; Bioassays
Pharmacology and Toxicology Dartmouth Medical School Remsen 7650 Hanover, NH 03755-3835
1332-21-4; 12001-29-5; 12001-28-4
Abstract; Conference/Symposia Proceedings
The FASEB Journal. Experimental Biology 95 - Annual Meeting of Professional Research Scientists, Atlanta, Georgia, April 9-13, 1995
Dartmouth College, Hanover, New Hampshire