title: Human epidermal keratinocytes are a source of tenascin-C during wound healing.
abstract: Tenascin-C is a large hexameric extracellular matrix glycoprotein that is expressed in a temporally and spatially restricted pattern associated with stromal-epithelial interactions. In adult human skin, the expression level of tenascin-C is low, but tenascin-C is abundantly present in the dermal compartment during embryogenesis and wound healing and in skin tumors. Herein we have investigated the cellular source of tenascin-C production in human skin, both in vivo and in vitro, by using immunohistochemistry, mRNA in situ hybridization, western blotting, and an enzyme-linked immunosorbent assay. In addition we studied the cell-matrix interaction between epidermal keratinocytes and purified tenascin-C. By using in vitro culture models, we found that keratinocytes not only synthesize and secrete tenascin-C but can also deposit tenascin-C in de-epidermized dermis in a pattern that is very similar to that in vivo. In vivo, during wound healing of normal human skin, we found tenascin-C extracellularly in the wound bed and also in a granular pattern within the neo-epidermis. By mRNA in situ hybridization, we could identify the basal migrated keratinocytes as the main source of tenascin-C in the early phase of wound healing. In the granulation phase, tenascin-C expression by the keratinocytes is downregulated. Cultured keratinocytes were found to adhere poorly to tenascin-C, and those that did adhere retained a rounded morphology. We conclude that human keratinocytes are a major source of tenascin-C during the early phase of wound healing, and we hypothesize that tenascin-C is unlikely to be an adhesive substrate for migrating keratinocytes.
authors.affiliation: Department of Dermatology, University Hospital Nijmegen, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Latijnhouwers
authors.forename: M
authors.initials: M
authors.lastname: Bergers
authors.forename: M
authors.initials: M
authors.lastname: Ponec
authors.forename: H
authors.initials: H
authors.lastname: Dijkman
authors.forename: M
authors.initials: M
authors.lastname: Andriessen
authors.forename: J
authors.initials: J
authors.lastname: Schalkwijk
mesh_terms: D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media / Q000494:pharmacology; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D012867:Skin / Q000166:cytology* / Q000378:metabolism; D019063:Tenascin / Q000096:biosynthesis* / Q000378:metabolism / Q000494:pharmacology; D014945:Wound Healing / Q000502:physiology*
chemical_list: D003470:Culture Media; D019063:Tenascin