Connective tissue growth factor induces extracellular matrix in asthmatic airway smooth muscle.
Transforming growth factor (TGF)-beta and connective tissue growth factor may be implicated in extracellular matrix protein deposition in asthma. We have recently reported that TGF-beta increased connective tissue growth factor expression in airway smooth muscle cells isolated from patients with asthma. In this study, we examined fibronectin and collagen production and signal transduction pathways after stimulation with TGF-beta and connective tissue growth factor. In both asthmatic and nonasthmatic airway smooth muscle cells, TGF-beta and connective tissue growth factor led to the production of fibronectin and collagen I. Fibronectin and collagen expression was extracellular regulated kinase-dependent in both cell types but phosphoinositide-3 kinase-dependent only in asthmatic airway smooth muscle cells. p38 was implicated in fibronectin but not collagen expression in both cell types. TGF-beta induction of fibronectin and collagen was in part mediated by an autocrine action of connective tissue growth factor. Phosphorylation of SMAD-2 may represent an additional pathway because this was increased in asthmatic cells. Our results suggest that these two cytokines may be important in the deposition of extracellular matrix proteins and that the signal transduction pathways may be different in asthmatic and nonasthmatic cells.
Johnson
Peter R A
PR
Department of Pharmacology, The University of Sydney, NSW, Australia.
Burgess
Janette K
JK
Ge
Qi
Q
Poniris
Maree
M
Boustany
Sarah
S
Twigg
Stephen M
SM
Black
Judith L
JL
D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000503:physiopathology*; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D055513:Connective Tissue Growth Factor; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis* / Q000187:drug effects; D005260:Female; D005353:Fibronectins / Q000096:biosynthesis; D006801:Humans; D017874:Immediate-Early Proteins / Q000494:pharmacology*; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D032389:Myocytes, Smooth Muscle / Q000187:drug effects*; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
C526317:CCN2 protein, human; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D016212:Transforming Growth Factor beta; D055513:Connective Tissue Growth Factor; D003094:Collagen