Production of plasminogen activator inhibitor-1 by human mast cells and its possible role in asthma.
The plasminogen activator inhibitor type 1 (PAI-1) has an essential role in tissue remodeling. The PAI-1 gene was induced by a combination of phorbol ester and calcium ionophore at the highest level among the inducible human mast cell genes that we have analyzed on a DNA microarray. PAI-1 was secreted by both a human mast cell line (HMC)-1 and primary cultured human mast cells upon stimulation, whereas PAI-1 was undetectable in either group of unstimulated cells. The secretion of PAI-1 was due to de novo synthesis of PAI-1 rather than secretion of preformed PAI-1. The functional significance of PAI-1 secretion was demonstrated by complete inhibition of tissue-type plasminogen activator activity with supernatants of stimulated HMC-1 cells. Furthermore, we were able to regulate PAI-1 gene expression in HMC-1 cells by known therapeutic agents. High-dose (1 microM) dexamethasone induced PAI-1 mRNA expression. Cyclosporin down-regulated the expression of the PAI-1 gene. Cycloheximide abrogated PAI-1 mRNA expression, suggesting that transcription of the PAI-1 gene requires de novo synthesis of early gene products, including transcription factors. Finally, we demonstrated PAI-1 in lung mast cells from a patient with asthmatic attack by double-immunofluorescence study. This is the first report demonstrating that activated human mast cells release a striking amount of functionally active PAI-1. These results suggest that PAI-1 could play an important role in airway remodeling of asthma, and inhibition of PAI-1 activity could represent a novel therapeutic approach in the management of airway remodeling.
Cho
S H
SH
Department of Pediatrics, and Division of Infectious Diseases, Torrance, CA 90509, USA.
Tam
S W
SW
Demissie-Sanders
S
S
Filler
S A
SA
Oh
C K
CK
D001249:Asthma / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D016572:Cyclosporine / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D005342:Fibrinolysis / Q000276:immunology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007700:Kinetics; D008168:Lung / Q000276:immunology / Q000378:metabolism; D008407:Mast Cells / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D010960:Plasminogen Activators / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000302:isolation & purification; D017455:Receptors, IgE / Q000276:immunology / Q000378:metabolism; D010959:Tissue Plasminogen Activator / Q000037:antagonists & inhibitors
D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D017455:Receptors, IgE; D003907:Dexamethasone; D016572:Cyclosporine; D003513:Cycloheximide; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator