Effect of growth factors on the migration of equine oral and limb fibroblasts using an in vitro scratch assay

The objective of this study was to determine the effect of platelet derived growth factor BB (PDGF), epidermal growth factor (EGF), transforming growth factor β1 (TGFβ1), insulin like growth factor-1 (IGF-1) and fibroblast growth factor-2 (FGF-2) on the proliferation and migration of equine oral mucosa and leg skin fibroblast cell lines, using an in vitro scratch assay. Fibroblasts from the two sites were firstly grown to confluence and then an area of cells removed (cell void area). Cell migration alone (with the addition of the mitosis inhibitor mitomycin-C to the culture media) and proliferation and migration combined (without mitomycin-C) into the cell void area were observed at 0, 5, 10, 24 and 36 h.

The presence of mitomycin-C in the culture media significantly slowed the closure of the cell void area, as mitosis was inhibited. For the oral cells only, TGFβ1 significantly slowed both migration (with mitomycin-C) and proliferation and migration combined (without mitomycin-C). For the limb cells only, both PDGF and FGF-2 significantly increased fibroblast proliferation and migration combined (without mitomycin-C). For both cell types, EGF significantly reduced migration (with mitomycin-C). IGF-1 had no effect on any of the parameters measured. It was concluded that TGFβ1, PDGF and FGF-2 have differential effects on the proliferation and migration of equine oral and limb fibroblasts. These differences in fibroblast responses to growth factors may in part form the basis of the different clinical outcomes for oral and limb wounds.