Epithelial-mesenchymal transition of the eccrine glands is involved in skin fibrosis in morphea.

Morphea is a type of localized scleroderma. It is a skin disease involving the development of fibrosis in the dermis and subcutaneous fat tissue beneath without a visceral lesion, and the cause is still unclear. An involvement of epithelial-mesenchymal transition (EMT) has been reported as a cause of tissue fibrosis, but this was mostly observed in pulmonary and hepatic fibrosis, and the involvement of EMT in a skin disease, morphea, has not been studied . Thus, we analyzed the involvement of EMT in skin fibrosis in morphea patients using pathological techniques. Skin lesions of six morphea patients were analyzed (five female and one male patient). As a control, non-light-exposed skin lesions of 11 healthy females were analyzed. Concretely, tissue samples were prepared from these subjects and subjected to immunostaining of transforming growth factor (TGF)-β1, α-smooth muscle actin (α-SMA) and fibronectin, which have been reported to be associated with fibrosis, and Snail1 and E-cadherin, which are considered to be involved in EMT, and expressions of these were analyzed. In morphea patients, dermal expression of TGF-β1, α-SMA and fibronectin, which are involved in fibrosis, was enhanced, and, at the same time, enhanced expression of Snail1 and reduced expression of E-cadherin, which are involved in EMT, were observed in the dermal eccrine glands. These findings suggested the progression of EMT in the dermal eccrine glands in morphea.