EXPRESSION OF SKALP ELAFIN DURING WOUND-HEALING IN HUMAN SKIN/

Skin-derived antileukoproteinase (SKALP), also known as elafin, is a p roteinase inhibitor with specificity for polymorphonuclear leucocyte ( PMN)derived elastase and proteinase-3. SKALP is absent in normal human epidermis, but is strongly induced in inflammatory dermatoses such as psoriasis, SKALP is putatively involved in the regulation of cutaneou s inflammation by inhibiting PMN derived proteinases. The aim of this study was to investigate SKALP expression and PMN infiltration during wound healing in human skin, This was examined in healing excisional w ounds in normal skin and in impaired healing in various types of chron ic venous ulcers, Tissues were analysed using immunohistochemistry and Northern blot analysis, Healing of excisional wounds was studied from day 0 to day 14, An influx of PMN was seen rapidly after wounding and was maximal between day 2 and 4 and then subsided, SKALP was induced within 48 h and was expressed in the suprabasal keratinocytes of the w ound edge and the migrating epidermal sheet, SKALP expression was maxi mal on day 4 and was downregulated at the time of complete reepithelia lization (7-14 days), In venous ulcers, PMN were abundant in the wound bed and scarce under the wound edge, SKALP was strongly expressed in the keratinocytes of the wound edge in all types of ulcers studied. In the wound bed, SKALP was not detectable. Our results suggest that SKA LP plays a role in the acute, inflammatory phase of wound healing. Fro m the kinetics and topology of SKALP expression we surmise that it neg atively regulates PMN infiltration.