Psoriasin (S100A7) is regulated by protein kinase C (PKC) and contributes to keratinocyte differentiation by regulating the expression of epidermal differentiation markers

• Psoriasis is a chronic inflammatory skin disease that is characterized by hyperproliferation and a disturbed maturation of the epidermal cells. The differentiation process of keratinocytes in active psoriatic lesions differs from that of normal epidermis, denoted by an altered expression of differentiation markers. Psoriasin, a protein which is highly expressed in psoriasis, is located within the epidermal differentiation complex (EDC), a gene cluster that contains several genes that are important in the terminal differentiation of the human epidermis. The potential role of psoriasin in keratinocyte differentiation remain however unclear. The aim of this present study was to investigate the possible involvement of psoriasin in keratinocyte differentiation. We demonstrated, by immunohistochemical staining, a gradient of psoriasin expression in the psoriatic epidermis, from an undefined or weak expression in the basal layer to an intense expression in the suprabasal differentiated layers. The expression of psoriasin was up-regulated in cultured keratinocytes in response to stimuli known to induce differentiation, such as an elevation of extracellular calcium or  12-Otetradecanoylphorbol-13-acetate (TPA). Down-regulation of psoriasin expression, by siRNA, resulted in decreased expression of the differentiation markers involucrin, desmoglein 1, transglutaminase 1 and CD24. Inhibition of protein kinase C (PKC) counteracted the calciuminduced expression of psoriasin and involucrin. In summary, our data demonstrate that psoriasin is regulated by the PKC signaling pathway and contributes to keratinocyte differentiation by the regulation of differentiation markers.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Reumatologi och inflammation (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Rheumatology and Autoimmunity (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences (hsv//eng)

Publication and Content Type

vet (subject category)

ovr (subject category)