Human sweat gland myoepithelial cells express a unique set of cytokeratins and reveal the potential for alternative epithelial and mesenchymal differentiation states in culture

作者：Margarete Schön, Jennifer Benwood, Therese O’Connell-Willstaedt, James G. Rheinwald · 发表于：Journal of Cell Science · 年份：1999 · DOI：10.1242/jcs.112.12.1925 · 被引用次数：70 · 研究领域：Skin and Cellular Biology Research、Wnt/β-catenin signaling in development and cancer、Cellular Mechanics and Interactions

We have characterized precisely the cytokeratin expression pattern of sweat gland myoepithelial cells and have identified conditions for propagating this cell type and modulating its differentiation in culture. Rare, unstratified epithelioid colonies were identified in cultures initiated from several specimens of full-thickness human skin. These cells divided rapidly in medium containing serum, epidermal growth factor (EGF), and hydrocortisone, and maintained a closely packed, epithelioid morphology when co-cultured with 3T3 feeder cells. Immunocytochemical and immunoblot analysis disclosed that the cells differed from keratinocytes in that they were E-cadherin-negative, vimentin-positive, and expressed an unusual set of cytokeratins, K5, K7, K14, and K17. When subcultured without feeder cells, they converted reversibly to a spindle morphology and ceased K5 and K14 expression. Under these conditions, EGF deprivation induced flattening, growth arrest, and expression of alpha-smooth muscle actin ((&agr;)-sma). Coexpression of keratins and alpha-sma is a hallmark of myoepithelial cells, a constituent of secretory glands. Immunostaining of skin sections revealed that only sweat gland myoepithelial cells expressed the same pattern of keratins and alpha-sma and lack of E-cadherin as the cell type we had cultured. Interestingly, our immunocytochemical analysis of ndk, a skin-derived cell line of uncertain identity, suggests that this line is of myoepithelial origin. Earlier immunohi...