Figure 5.

Effects of fibroblast receptor knockdown on fibroblast non–cell-autonomous invasion. (A) Quantitative PCR demonstrating the mRNA expression of the relevant genes after small interfering RNA (siRNA)-mediated receptor knockdown. (B) Transfection with siRNA targeting platelet-derived growth factor receptor-β (PDGFRβ) reduced the invasion of lung fibroblasts from unchallenged mice that was induced by PDGF-BB. (C) Transfection with siRNAs targeting PDGFRβ, LPA₁, epidermal growth factor receptor (EGFR), and fibroblast growth factor receptor 2 (FGFR2), but not transforming growth factor-β receptor 1 (TGF-βR1), reduced the invasion of lung fibroblasts from unchallenged mice that was induced by BAL recovered from mice at D7 after challenge with 1.2 U/kg bleomycin. Data are presented as percentage of the invasion of fibroblasts transfected with nontargeting (NT) siRNA that was induced by the same BAL samples acting on fibroblasts transfected with targeting siRNAs (n = 3 mice as the source of lung fibroblasts, and n = 3 as the source of BAL; *P < 0.05, ***P < 0.001).