Epidermal keratinocytes migrate over a provisional matrix during the re-epithelialization of cutaneous wounds. We have investigated the expression of integrins and of transforming growth factor-β1 (TGF-β1) during re-epithelialization in a porcine model. Tissue specimens were collected at different times after injury and stained with antibodies against subunits of the fibronectin receptor, integrin α5β1, and the vitronectin receptor, integrin αvβ5. Intense staining was observed in the migrating keratinocytes of 5-d wounds; basal and suprabasal cells were stained around the entire cell periphery. Staining returned toward normal levels in 14-d wounds. The appearance of the extracellular form of TGF-β1 seemed to be coordinated with the increased expression of integrin subunits: it was detected in migrating keratinocytes and in the adjacent epidermis of early wounds at 5 and 7 d. We also investigated the effect of TGF-β1 on cultured epidermal cells. Treating human keratinocytes with TGF-β1 increased the levels of mRNA for the integrin subunits α5, αv, and β5, but had little effect on β1. The corresponding cell-surface expression of α5 and αv was also increased after treatment. Thus, during wound repair, TGF-β1 may induce epidermal keratinocytes to express integrins that facilitate the migratory component of re-epithelialization.