Figure 1

Secreted protein acidic and rich in cysteine (SPARC) expression is induced by selective transforming growth factor (TGF)-β stimulation. (A) HFL-1 cells were treated with profibrotic factors for 24 h and SPARC gene expression was quantified by real-time PCR and normalized relative to 18S rRNA. **P <0.01 versus control. (B) and(C) SPARC expression in HFL-1 cells stimulated with TGF-β for the indicated times at the indicated concentration. SPARC expression was analyzed by real-time PCR, and relative SPARC expression was calculated by comparison with the non-stimulated SPARC level at each time point (B) or by western blotting (C). (D) Total lung RNA was isolated from homogenates of lungs from mice treated with vehicle or ALK5 inhibitor, 11 days after intratracheal instillation of saline or bleomycin. SPARC, Col1A1 and Fibronectin gene expression were quantified by real-time PCR and normalized relative to 18S rRNA. *P <0.05, **P <0.01 versus control;^#P <0.01 versus vehicle. (A) and (B) represent the means of three independent experiments ± SE.