Fibronectin release by systemic sclerosis and normal dermal fibroblasts in response to TGF-beta.
To determine whether enhanced matrix synthesis by systemic sclerosis (SSc) fibroblasts in vitro is due to increased responsiveness to transforming growth factor-beta (TGF-beta), fibronectin release by SSc and normal fibroblasts (7 pairs) was measured at various concentrations of TGF-beta. In the absence of TGF-beta, SSc fibroblasts released 30 +/- 22% more fibronectin than normal fibroblasts. While both SSc and normal fibroblasts increased fibronectin release at all concentrations of TGF-beta tested, the percentage increases were not statistically greater for the SSc fibroblasts even though 4 of the SSc fibroblasts strains were selectively sensitive to low concentrations of TGF-beta. TGF-beta increased cell numbers of both SSc and normal strains equally. Our data confirm abnormal regulation of fibronectin gene expression in SSc fibroblasts and suggest increased sensitivity to TGF-beta by some SSc fibroblast strains.
Xu
W D
WD
Department of Medicine, Medical University of South Carolina, Charleston 29425.
Leroy
E C
EC
Smith
E A
EA
D015153:Blotting, Western; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D012595:Scleroderma, Systemic / Q000378:metabolism* / Q000473:pathology; D012867:Skin / Q000166:cytology / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D005353:Fibronectins; D016212:Transforming Growth Factor beta