Figure 6

Bone marrow-derived myofibroblasts contribute to bleomycin-induced pulmonary fibrosis. C57Bl/6 mice were lethally irradiated and reconstituted with bone marrow of syngeneic C57Bl/6-EGFP animals. 6 weeks after bone marrow reconstitution, some of the chimeric mice received bleomycin to induce pulmonary fibrosis. In the lung of unchallenged chimeric mice, EGFP-positive cells were negative for SP-C (A) and αSMA (B). In the chimeric mice 7 days after bleomycin instillation, EGFP-positive cells accumulated in the inflamed lung tissue but were negative for SP-C (C) and αSMA (D). 21 days after treatment with bleomycin, some EGFP⁺ cells were positive for αSMA (F), but not for SP-C (E). DAPI visualized cell nuclei. Bars = 20 μm.