FIGURE 4.

Systemic administration of S1P primes pulmonary fibroblasts. Pulmonary fibroblasts were harvested from mice (n = 6) treated with either vehicle or S1P. Morphological changes were assessed by light microscopy ×10 magnification (a). Fibroblast proliferation was assessed by MTT assay (b). Data are expressed as mean ± SEM. **p < 0.01 vs. vehicle; ***p < 0.001 vs. vehicle as assessed by two‐way ANOVA followed by Bonferroni post‐test. Fibroblast differentiation was evaluated by immunofluorescence analysis by using a mouse monoclonal antibody against α‐SMA (c)