Immunohistochemical obervation of EGF,TGF - alpha and EGF-R in psoriatic epidermis

Ha, Sang Keun; Lee, Seung Chul; Won, Young Ho; Chun, Inn Ki; Kim, Young Pio

Abstract

Epidermal growth factor(KGF) and transforming growth factor arpha(TGF-a) are polypeptides of 53 amd 50 amino acid residuies. Both bind to epidermal growth factor receptor (EGR-R) leading to phosphorylation of the receptor, enhancement of its tyrosine-specific kinase activity and ultimately to stimulation of cell growth. To study he role of EGF, TGF-a, and EGF-R in differentiation and hyperproliferation of cell, we se lected psoriasis vulgaris, because the affected keratinocyte may house both an abnormally increased proliferative capacity and an abnormally differentiated state. The biopsy specimens were taken from involved and uninvolved skin of 20 patients with psoriasis and immunoperoxidase studies with formalin-fixed paraffin-embedded tissues were performed with EGF, TGF-a and EGF-R useing the Vectastain ABC irnmunoperoxidase stain system. The antibodies were used at a concentration of 6 ug/ml In involved psoriatic skin, distributions of TGF-a and EGF-R were increased in all layers of epidermis as compared to normal, uninvolved psoriatic skin, in which chev were showed to the basal and parabasal layers. However, distribution of EGF was weekly positive in the basal layers of epidermis in both involved and uninvolved skin with no difference between toem. These results suggest that increased distribution of TGF-a and EGF-R may be involved in hypoproliferative state of epidermal keratinocytes in psoriatic lesion.