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Suppression of the neutral protease activity of macrophages treated with asbestos in vitro
Abstract:
Macrophages are often conspicuous in asbestos-induced inflammatory lesions. Chrysotile type B elicits macrophages into the peritoneal cavity of mice which produce high levels of the neutral protease, plasminogen activator; in vitro addition of these same fibers to mouse peritoneal macrophages stimulates enzyme production. It is reported here that, for endotoxin-elicited mouse peritoneal macrophages fed chrysotile type B in vitro, the increased plasminogen activator activity is suppressed by low concentrations of anti-inflammatory steroids. Other active drugs include colchicine and vinblastine. These studies are considered important, as they suggest an approach to controlling the levels of a potentially deleterious enzyme system (PA-plasmin) from macrophages treated with asbestos fibers.
Insights
Anti-inflammatory steroids and drugs like colchicine can suppress elevated plasminogen activator (PA) enzyme levels in macrophages exposed to asbestos fibers. This finding offers a potential method to control asbestos-induced inflammation.
Area of Science:
- Immunology
- Toxicology
- Biochemistry
Background:
- Macrophages are key players in asbestos-induced inflammatory responses.
- Asbestos exposure, specifically chrysotile type B, stimulates macrophages to produce plasminogen activator (PA), a neutral protease.
- Elevated PA-plasmin activity may contribute to tissue damage during asbestos-related inflammation.
Purpose of the Study:
- To investigate the effect of anti-inflammatory drugs on PA production by macrophages exposed to asbestos.
- To explore potential therapeutic strategies for mitigating asbestos-induced macrophage activation and enzyme release.
Main Methods:
- Mouse peritoneal macrophages were elicited and cultured in vitro.
- Macrophages were exposed to chrysotile type B asbestos fibers.
- The activity of plasminogen activator (PA) was measured.
- The effects of anti-inflammatory steroids, colchicine, and vinblastine on PA activity were assessed.
Main Results:
- Chrysotile type B asbestos fibers significantly increased PA activity in mouse peritoneal macrophages.
- Low concentrations of anti-inflammatory steroids effectively suppressed the asbestos-induced increase in PA activity.
- Colchicine and vinblastine also demonstrated activity in suppressing PA levels.
Conclusions:
- Anti-inflammatory steroids and certain drugs can inhibit the enhanced PA activity in macrophages exposed to asbestos.
- These findings suggest a potential therapeutic approach to manage the deleterious effects of asbestos-induced inflammation by controlling macrophage-derived PA-plasmin systems.