Spatial and temporal expression of basic fibroblast growth factor protein during wound healing of rat skin

Basic fibroblast growth factor (bFGF) stimulates the mitogenesis of various cells and plays a key part in wound healing.

To determine the spatial and temporal expression of bFGF protein during wound healing after burning of rat skin.

Immunohistochemical methods were used.

The immunostaining for bFGF in the normal epidermis was faint and sporadic in the basal cell layer. However, significant staining for bFGF was found in four locations: regenerated epidermis, a band-like zone near the regenerated epidermis, renewed capillaries, and cells infiltrating into the granulation tissue at the inflammatory to proliferative stages after the burn. The intensity of immunostaining of regenerated epidermis, the band-like zone and renewed capillaries was maximal during the proliferative stage and decreased to normal levels or disappeared simultaneously with wound closure. Immunopositive macrophage-like cell numbers in the granulation tissue increased during the proliferative stage and promptly decreased after wound closure, but such cells were only poorly visible in the scar tissue until 42 days postburn.

bFGF may affect the proliferation, differentiation and migration of regenerated keratinocytes and the recruitment of inflammatory cells, as well as neovascularization in granulation tissue during wound healing. Macrophages may play a pivotal role in cutaneous wound repair by producing bFGF not only during the inflammatory or proliferative stages but also during the remodelling stage.