Notch Intracellular Domain Expression in Various Skin Fibroproliferative Diseases

BACKGROUND The effects of the Notch signaling pathway in fibroproliferative skin diseases have not been fully elucidated. OBJECTIVE The aim of this study was to investigate the expression of activated Notch signaling molecules in various skin fibroproliferative diseases. METHODS Immunohistochemical analysis of Notch intracellular domain (NICD) expression in keloid, hypertrophic scar, morphea, dermatofibroma, and normal control skin specimens was performed, and the clinical characteristics of patients with various skin fibroproliferative diseases were analyzed. RESULTS NICD was highly expressed in fibroblasts of keloids and moderately to highly expressed in hypertrophic scars and dermatofibromas, whereas low or no expression was detected in the fibroblasts of normal skin specimens and morpheas. NICD was constitutively expressed in keratinocytes, endothelial cells, and immune cells in normal skin specimens. CONCLUSION NICD was significantly expressed in human fibroproliferative skin disorders, especially keloids, suggesting that an activated Notch signaling pathway is involved in the pathogenesis of skin fibrosis.