Altered compartmentalization of transforming growth factor-beta in asthmatic airways.
BACKGROUND
Asthma is characterized by alterations of the bronchial epithelium associated with inflammatory cell infiltrates and sub-epithelial fibrosis. Transforming Growth Factor-beta (TGF-beta) is an anti-inflammatory and fibrosing cytokine normally present in bronchial epithelial cells and also potentially produced by inflammatory cells. Thus, TGF-beta could play a role in the asthmatic process, and its expression could be modified in asthmatic airways.


OBJECTIVE
To test this latter hypothesis, we studied the bronchial distribution of TGF-beta in asthmatic patients.


METHODS
TGF-beta 1, 2, 3 distribution was studied by immunohistochemistry in bronchial biopsies from 12 asthmatic patients and 10 non-asthmatic subjects.


RESULTS
Bronchial epithelial cells from asthmatics were negative or faintly positive while a bright staining was detected in these from non-asthmatics (P < 0.01). In both groups, when inflammatory cells were present beneath the basement membrane, they were stained by the anti-TGF-beta antibody.


CONCLUSIONS
This study shows an altered compartimentalization of TGF-beta in asthma. (a) TGF-beta is scarse in asthmatic bronchial epithelial cells, which could favour the perennization of the bronchial inflammation, and (b) TGF-beta is present in inflammatory cells beneath the basement membrane, where it could be involved in the frequent sub-epithelial fibrosis.
Magnan
A
A
Chest Medicine and Allergology Department, Ste-Marguerite Hospital, Lille, France.
Retornaz
F
F
Tsicopoulos
A
A
Brisse
J
J
Van Pee
D
D
Gosset
P
P
Chamlian
A
A
Tonnel
A B
AB
Vervloet
D
D
D000328:Adult; D000368:Aged; D001249:Asthma / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology; D001485:Basement Membrane / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D001980:Bronchi / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D016022:Case-Control Studies; D004848:Epithelium / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D006801:Humans; D018928:Immunity, Mucosal; D007150:Immunohistochemistry; D008875:Middle Aged; D014018:Tissue Distribution; D016212:Transforming Growth Factor beta / Q000378:metabolism*
D016212:Transforming Growth Factor beta