title: Epithelial differentiation in the absence of extracellular matrix.
abstract: To investigate the regulation of epithelial differentiation, normal human epidermal keratinocytes were cultured floating on the surface of culture medium without attachment to a solid substrate. Keratinocytes spread out on the surface of the medium, proliferated and differentiated either into several flat lacy sheets 1 to 3 cells thick (on medium containing 0.15 mM calcium) or formed one single aggregate of cells from 5 to 15 cells in thickness on medium containing 1.15 mM calcium. The cell aggregates demonstrated a pattern of ordered epithelial differentiation. Levels of progressive differentiation resembling the structure of normal human epidermis were identified by light microscopy, immunohistochemistry, and electron microscopy. Differentiation proceeded from cells at the air side toward cells at the medium side with basal appearing cells on the air side and keratinocytes expressing filaggrin and involucrin on the side toward the medium. These results demonstrate that organized epithelial differentiation can occur in the absence of extracellular matrix. In contrast with other air-liquid interface cultures, epithelial differentiation in the absence of extracellular matrix progresses from air towards medium.
authors.affiliation: Department of Dermatology, Stanford University, School of Medicine, California 94305.
authors.forename: N C
authors.initials: NC
authors.lastname: Krejci
authors.forename: L
authors.initials: L
authors.lastname: Smith
authors.forename: R
authors.initials: R
authors.lastname: Rudd
authors.forename: R
authors.initials: R
authors.lastname: Langdon
authors.forename: J
authors.initials: J
authors.lastname: McGuire
mesh_terms: D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D004847:Epithelial Cells; D004848:Epithelium / Q000502:physiology / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000502:physiology*; D000091344:Filaggrin Proteins; D006801:Humans; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000378:metabolism; D015603:Keratinocytes / Q000166:cytology* / Q000502:physiology / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D011498:Protein Precursors / Q000378:metabolism
chemical_list: C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins; D011498:Protein Precursors; C032253:involucrin