title: Functional and immunoreactive thrombomodulin expressed by keratinocytes.
abstract: In an immunohistopathologic study using two monoclonal antibodies that recognize independent epitopes on human thrombomodulin, we detected expression of thrombomodulin on Malpighian-layer keratinocytes, but not on the basal or upper granular-layer keratinocytes. Western blotting and thrombomodulin-specific enzyme-linked immunosorbent assay performed on both shaved skin and cultured SV40-transformed keratinocytes showed the expression of full-length thrombomodulin, indistinguishable from endothelial thrombomodulin. Thrombomodulin was expressed by keratinocytes in 1 mM calcium but not in reduced calcium. A functional assay for thrombomodulin revealed that epidermal-derived thrombomodulin possessed cofactor activity for thrombin-catalyzed protein C activation. The limited pattern of expression of thrombomodulin in epidermis implies that this molecule may be a differentiation marker of keratinocytes in addition to being a potent anticoagulant in the skin.
authors.affiliation: Department of Dermatology, Mie University, Faculty of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Mizutani
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: N
authors.initials: N
authors.lastname: Nouchi
authors.forename: S
authors.initials: S
authors.lastname: Ohyanagi
authors.forename: K
authors.initials: K
authors.lastname: Hashimoto
authors.forename: M
authors.initials: M
authors.lastname: Shimizu
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D015153:Blotting, Western; D002478:Cells, Cultured; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000737:chemistry*; D011994:Recombinant Proteins / Q000276:immunology; D018180:Thrombomodulin / Q000276:immunology* / Q000502:physiology*; D014020:Tissue Extracts / Q000737:chemistry
chemical_list: D011994:Recombinant Proteins; D018180:Thrombomodulin; D014020:Tissue Extracts