title: Expression of caspase-14 and keratin-19 in the human epidermis and appendages during fetal skin development.
abstract: Caspase-14 is a seemingly non-apoptotic caspase involved in keratinocyte differentiation and cornification of the skin. Keratin-19 is an epithelial marker and a potential marker of epidermal stem cells that is expressed during human fetal skin development. We examined the immunohistochemical expression of caspase-14 in relation to CK-19 in the human fetal skin during development and perinatally, to assess their role in human skin maturation. Skin samples were received at autopsy. In the fetal epidermis, caspase-14 was predominantly expressed in the more differentiated layers, gradually disappearing from the basal layer toward term. By contrast, keratin-19 expression gradually decreased with epidermal maturation through gestation (rho = -0.949; p = 0.0001) and was a marker of the germinative layers. Keratin-19 was preserved in scarce basal cell nests at term and postnatally. Caspase-14 and keratin-19 were inversely expressed in the differentiating epidermal layers through gestation (p < 0.0001). Concerning the appendages, in hair follicles and sebaceous glands, caspase-14 located preferentially in the more differentiated layers of the inner root sheath, whereas keratin-19 was expressed in the outer sheath. Eccrine sweat glands showed a variable pattern of caspase-14 and keratin-19 expression. In conclusion, caspase-14 emerged as a marker of human skin differentiation during development, while keratin-19 marked the germinative epithelial layers in the fetal epidermis and appendages and possibly the nests of epidermal stem cells.
authors: 1st Department of Pathology, Medical School, University of Athens, 75 M.Asias Street, 11527 Athens, Greece.
authors: Ioannis D
authors: ID
authors: Gkegkes
authors: Kyriaki
authors: K
authors: Aroni
authors: George
authors: G
authors: Agrogiannis
authors: Efstratios S
authors: ES
authors: Patsouris
authors: Anastasia E
authors: AE
authors: Konstantinidou
mesh_terms: D001344:Autopsy; D015415:Biomarkers / Q000032:analysis; D020169:Caspases / Q000032:analysis*; D002454:Cell Differentiation; D004817:Epidermis / Q000737:chemistry* / Q000196:embryology / Q000201:enzymology; D004847:Epithelial Cells / Q000737:chemistry* / Q000201:enzymology; D005865:Gestational Age; D018859:Hair Follicle / Q000737:chemistry* / Q000196:embryology / Q000201:enzymology; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D053539:Keratin-19 / Q000032:analysis*; D012189:Retrospective Studies; D012627:Sebaceous Glands / Q000737:chemistry* / Q000196:embryology / Q000201:enzymology; D013545:Sweat Glands / Q000737:chemistry* / Q000196:embryology / Q000201:enzymology
chemical_list: D015415:Biomarkers; D053539:Keratin-19; C506446:CASP14 protein, human; D020169:Caspases