FOXM1 expression is induced in macrophages within human IPF and mouse fibrotic lungs.

(A) FOXM1 (red) is not expressed in CD68⁺ macrophages (green) of control donor lungs (upper panels) but is upregulated in macrophages within fibrotic lesions (middle panels) and adjacent alveolar regions (bottom panels) of idiopathic pulmonary fibrosis (IPF) lungs. (B) Percent of FOXM1⁺/CD68⁺ double positive cells were counted in 5 random fields and presented as mean ± SEM. Scale bar = 20μm. (C) FOXM1 (brown) is not expressed in control mouse lungs and gradually increased during the progression of bleomycin-induced pulmonary fibrosis in mice. Numbers of FOXM1⁺ cells were counted in 5 random fields and presented as mean ± SEM. N = 3 mice per group. Scale bar = 100μm. (D) FOXM1 (red) is not expressed in MAC3⁺ macrophages (green) of control mouse lungs (upper panels) but is upregulated in macrophages within fibrotic lesions and adjacent alveolar regions of bleomycin-injured fibrotic lungs (bottom panels). (E) Percent of FOXM1⁺/MAC3⁺ double positive cells were counted in 5 random fields and presented as mean ± SEM. N = 3 mice per group. Scale bar = 20μm. (F) Foxm1 mRNA is increased in BALF cells from bleomycin-treated mice as determined by qRT-PCR. Actb mRNA was used for normalization. N = 3 mice per group. * = P < 0.05. *** = P < 0.0001.