Dynamic changes in gene expression after PNX. qRT-PCR was performed to determine RNA expression in primary lung fibroblasts or primary lung epithelial cells 3 and 5 days after PNX. (A) Genes expressed in structural fibroblasts: PDGFR-α, acta2, Fabp4, tenascin C. (B) Retinoic acid signaling in fibroblasts: RXR-α, RXR-β, Midkine. (C) FGFR3 and FGFR4 in fibroblasts and epithelial FGF9. (D) Wnt2a in fibroblasts and epithelial β-catenin, Shh, and Bmp4. Gene mRNA levels of SHAM (white bars), PNX (black bars), PNX+dnFGFR (light gray bars), and PNX+RZG (dark gray bars) were compared. Results were normalized to ribosomal L32 mRNA. Results are expressed as the means ± SEM of three to seven animals per group, and differences were analyzed by Students’ t test (*P < 0.05). Only genes and time points with significant changes are shown.