A role of Foxc2 gene in mice with bleomycin-induced pulmonary fibrosis

Background: Foxc2 is one of the forkhead transcriptional factors, which are expressed in mesenchymal cells and influence their migration. Recently, there are some reports on the relationship of mesenchymal cells and pulmonary fibrosis. We therefore hypothesized that Foxc2 gene may also be related to the pulmonary fibrosis. Objective: To elucidate the role of Foxc2 gene in pulmonary fibrosis, we investigated Foxc2 mutant mice exposed with bleomycin to induce pulmonary fibrosis. Materials & methods: ICR- Foxc2 heterozygotes (n=3) and wild type (7-14 weeks) (n=5) mice were injected a single dose of bleomycin hydrochloride (1mg/kg bodyweight) into the trachea using 28G needle under anesthesia, histologically examined after 14 days. Lungs were fixed with 4% paraformaldehyde, and their paraffin-sections and cryo-sections (5µm) were made. immunohistochemically. We performed hematoxylin-eosin staining on paraffin sections for estimating the fibrosis grade by Ashcroft9s score (AC). To estimate the epithelial cell renewal processes, we examined the expressions of podoplanin and prosurfactant protein-C (proSP-C), as markers for type1 and type2 alveolar cells, respectively. Results: We found significant difference (P Foxc2 +/- (AC: 2.84) mice. Although some of proSP-C+ cells became squamous shape in both groups, there was no difference in the expression and the shape of podoplanin+ cells. There was no numerical difference in the two types of alveolar cells, either. Conclusions: These data suggest that Foxc2 may control the severity of lung fibrosis, but have little effect on the alveolar cell renewal.