In vitro effects of flunisolide on MMP-9, TIMP-1, fibronectin, TGF-beta1 release and apoptosis in sputum cells freshly isolated from mild to moderate asthmatics.
BACKGROUND
Corticosteroids play an important role in inflammation and remodelling of airways and are considered an important therapeutic target in asthma. Inflammation in asthma is characterized by a dysregulation of eosinophil apoptosis and of markers of airways remodelling. We evaluated the ability of flunisolide to inhibit in vitro the release of metalloproteinases-9 (MMP-9), tissue inhibitor metalloproteinases-1 (TIMP-1), transforming growth factor (TGF-beta) and fibronectin by sputum cells (SC) as well as to induce sputum eosinophil apoptosis.


METHODS
The SC, isolated from induced sputum samples of 12 mild-to-moderate asthmatics, were cultured for 24 h in the presence or absence of flunisolide (1, 10 and 100 microM). The release of mediators was assessed by enzyme-linked immunosorbent assay (ELISA) whereas apoptosis was studied by TUNEL technique.


RESULTS
Flunisolide (10 microM) significantly reduced MMP-9 and TIMP-1 (P = 0.0011 and P < 0.0001 respectively) and increased MMP-9/TIMP-1 molar ratio (P = 0.004). In addition, flunisolide decreased TGF-beta and fibronectin release by SC (P = 0.006; and P < 0.0001 respectively) and increased eosinophil apoptosis (P < 0.001).


CONCLUSIONS
These results demonstrate that flunisolide may play an important role in the inhibition of airway inflammation and remodelling, by promoting the resolution of eosinophilic inflammation and by inhibiting the release of MMP-9, TIMP-1, TGF-beta and fibronectin.
Profita
M
M
Istituto di Biomedicina e Immunologia Molecolare, Consiglio Nazionale delle Ricerche, Palermo, Italy.
Gagliardo
R
R
Di Giorgi
R
R
Bruno
A
A
Riccobono
L
L
Bonanno
A
A
Bousquet
J
J
Vignola
A M
AM
D000328:Adult; D017209:Apoptosis / Q000187:drug effects*; D001249:Asthma / Q000188:drug therapy* / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism*; D005446:Fluocinolone Acetonide / Q000031:analogs & derivatives* / Q000494:pharmacology*; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008875:Middle Aged; D013183:Sputum / Q000166:cytology / Q000378:metabolism*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D053773:Transforming Growth Factor beta1
D005353:Fibronectins; C508960:TGFB1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D005446:Fluocinolone Acetonide; C007734:flunisolide; D020780:Matrix Metalloproteinase 9