Release of transforming growth factor-beta (TGF-beta) and fibronectin by alveolar macrophages in airway diseases.
Asthma and chronic bronchitis are associated with airway remodelling, and airway macrophages are present in bronchial inflammation. TGF-beta and fibronectin released by alveolar macrophages possess a fibrogenic potency. The potential role of alveolar macrophages in airway remodelling was studied in asthma and chronic bronchitis by the release of TGF-beta and fibronectin. Alveolar macrophages were isolated by bronchoalveolar lavage in 14 control subjects, 14 asthmatics and 14 chronic bronchitics. The spontaneous and lipopolysaccharide (LPS)- or concanavalin A (Con A)-induced release of TGF-beta and fibronectin was measured by ELISA. Alveolar macrophages from chronic bronchitics spontaneously release greater amounts of TGF-beta and fibronectin than those from asthmatic and control subjects. Alveolar macrophages from asthmatics release greater amounts of TGF-beta and fibronectin than those from control subjects. The spontaneous release of TGF-beta is significantly correlated with that of fibronectin. Fibronectin release was significantly reduced after LPS stimulation, and TGF-beta release was significantly increased after LPS stimulation, except in chronic bronchitis patients. Con A increased the release of TGF-beta in cells from normal subjects. This study suggests that activated macrophages play a role in airway remodelling in chronic bronchitis and to a lesser extent in asthma.
Vignola
A M
AM
Istituto di Fisiopatologia Respiratoria, C.N.R., Palermo, Italy.
Chanez
P
P
Chiappara
G
G
Merendino
A
A
Zinnanti
E
E
Bousquet
J
J
Bellia
V
V
Bonsignore
G
G
D000328:Adult; D001249:Asthma / Q000276:immunology* / Q000378:metabolism; D001991:Bronchitis / Q000276:immunology* / Q000378:metabolism; D002908:Chronic Disease; D003208:Concanavalin A / Q000494:pharmacology; D005260:Female; D005353:Fibronectins / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D016676:Macrophages, Alveolar / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D016212:Transforming Growth Factor beta / Q000187:drug effects / Q000378:metabolism*
D005353:Fibronectins; D008070:Lipopolysaccharides; D016212:Transforming Growth Factor beta; D003208:Concanavalin A