Interleukin-1 enhances epidermal wound healing.

Previous in vitro studies suggest that the interleukin-1 (IL-1) proteins may be important for skin function. Keratinocytes are known to synthesize IL-1 in response to injury and IL-1 has been shown to stimulate fibroblast and keratinocyte growth, collagen synthesis by fibroblasts, and chemotaxis of keratinocytes. In order to evaluate the ability of IL-1 to enhance wound healing, recombinant human IL-1 alpha was applied topically in a water-miscible cream to partial thickness wounds made on the backs of pathogen-free adult pigs. The wounded site was excised at various times for assessment of epidermal regeneration. This study shows a statistically significant enhancement of healing of the IL-1-treated wounds compared with either air-exposed or vehicle-treated wounds. Histologic examination of biopsies from IL-1-treated wounds indicated complete and architecturally normal epidermal regeneration. Porcine keratinocytes and membranes prepared from porcine skin were found to possess high affinity receptors for human IL-1 alpha. This study suggests that topical administration of IL-1 may be useful for the promotion of wound healing.