Expression of caspase-14 and keratin-19 in the human epidermis and appendages during fetal skin development

Arch Dermatol Res. 2013 Jul;305(5):379-87. doi: 10.1007/s00403-013-1319-8. Epub 2013 Feb 3.

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.

MeSH terms

  • Autopsy
  • Biomarkers / analysis
  • Caspases / analysis*
  • Cell Differentiation
  • Epidermis / chemistry*
  • Epidermis / embryology
  • Epidermis / enzymology
  • Epithelial Cells / chemistry*
  • Epithelial Cells / enzymology
  • Gestational Age
  • Hair Follicle / chemistry*
  • Hair Follicle / embryology
  • Hair Follicle / enzymology
  • Humans
  • Immunohistochemistry
  • Infant, Newborn
  • Keratin-19 / analysis*
  • Retrospective Studies
  • Sebaceous Glands / chemistry*
  • Sebaceous Glands / embryology
  • Sebaceous Glands / enzymology
  • Sweat Glands / chemistry*
  • Sweat Glands / embryology
  • Sweat Glands / enzymology

Substances

  • Biomarkers
  • Keratin-19
  • CASP14 protein, human
  • Caspases