Figure 2.

Alveolar α smooth muscle action (α-SMA) expression is induced 5 days after PNX. Immunohistochemistry for α-SMA (A–D, red) and NG2 (E–H, red) was performed on lung sections of adult mice 7 days after SHAM (A, E), PNX (B, F), PNX+dnFGFR (C, G), and PNX+RZG (D, H). α-SMA expression was found in peribronchiolar and perivascular fibroblasts in all lungs. Nuclear PDGFR-α–GFP signal could only be found in alveolar fibroblasts (B, arrowhead and insert) and was not found in peribronchiolar or perivascular SMA-positive fibroblasts (A, C, D, arrows). Five days after surgery, α-SMA was induced in PDGFR-α–GFP–positive interstitial fibroblasts (B, arrow). NG2 expression was found in the lung interstitium in all experimental groups and was never colocalized with nuclear PDGFR-α–GFP. Low-magnification inserts in E through H provide overall distribution patterns. Scale bar, 10 μm. Red in A through D: α-SMA. Red in E through H: NG2. Blue: DAPI. Green: PDGFR-α–GFP. B = brochus; V = vessel.