The role of the epidermal 12-hydroxyeicosatetraenoic acid receptor in the skin.

The epidermal layer of the skin is the site of active arachidonic acid metabolism. The main product of epidermal keratinocytes is the 12-lipoxygenase derivative 12(S)-hydroxy-eicosatetraenoic acid (12(S)-HETE). Its biological effects in skin are mediated via specific, high affinity binding sites present on both keratinocytes and epidermal antigen presenting Langerhans cells. The main biological effect is chemotaxis of keratinocytes suggesting a physiological role of 12-HETE in cutaneous wound healing. Analysis of 12-HETE receptors in various cutaneous disease states revealed a dramatic defect in lesional and uninvolved psoriatic skin which may represent a central molecular defect in the pathophysiology of the disease.