A phosphodiesterase 4 inhibitor inhibits matrix protein deposition in airways in vitro.
BACKGROUND
Airway smooth muscle (ASM) cells may contribute to airway remodeling through the release of growth factors, cytokines, and extracellular matrix (ECM) proteins. The effect of current asthma therapies on this release is not known.


OBJECTIVE
We examined the effect of corticosteroids, long-acting beta(2)-agonists, and a phosphodiesterase 4 (PDE4) inhibitor on ASM-released connective tissue growth factor (CTGF), collagen I, fibronectin, versican, and IL-6.


METHODS
Airway smooth muscle cells from individuals with and without asthma were stimulated with TGF-beta with or without the drugs and CTGF and ECM protein expression measured by real-time PCR, cell surface, or matrix-associated ELISA. IL-6 release was measured by ELISA. Bronchial rings from individuals without asthma were incubated with TGF-beta with or without the drugs.


RESULTS
Neither corticosteroids nor long-acting beta(2)-agonists reduced TGF-beta-induced CTGF, collagen I, or fibronectin in either cell type, whereas corticosteroids alone induced the expression of CTGF, collagen I, and fibronectin. These drugs did not prevent the accumulation of TGF-beta-induced proteins in bronchial rings, whereas the PDE4 inhibitor roflumilast inhibited TGF-beta-induced CTGF, collagen I, and fibronectin.


CONCLUSIONS
In our model, current asthma therapies are not able to inhibit matrix protein deposition from ASM cells. The results of this study suggest that the PDE4 inhibitor roflumilast may have a role in regulating the ECM and therefore aspects of airway remodeling in asthma.


CONCLUSIONS
Although current asthma therapies are effective in reducing inflammation and symptoms, reversal or prevention of structural changes contributing to remodeling may require additional therapy, which could include PDE4 inhibitors.
Burgess
Janette K
JK
Department of Pharmacology, University of Sydney, NSW, Australia. janette@pharmacol.usyd.edu.au
Oliver
Brian G G
BG
Poniris
Maree H
MH
Ge
Qi
Q
Boustany
Sarah
S
Cox
Natalie
N
Moir
Lyn M
LM
Johnson
Peter R A
PR
Black
Judith L
JL
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000328:Adult; D000631:Aminopyridines / Q000494:pharmacology*; D001549:Benzamides / Q000494:pharmacology*; D001980:Bronchi / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D002478:Cells, Cultured; D024042:Collagen Type I / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D055513:Connective Tissue Growth Factor; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D003521:Cyclopropanes / Q000494:pharmacology; D016326:Extracellular Matrix Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D005353:Fibronectins / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D017874:Immediate-Early Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis / Q000235:genetics; D008168:Lung / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D008875:Middle Aged; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis
D000631:Aminopyridines; D001549:Benzamides; C526317:CCN2 protein, human; D024042:Collagen Type I; D003521:Cyclopropanes; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; C424423:Roflumilast; D055513:Connective Tissue Growth Factor; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4