title: High-cell-density phorbol ester and retinoic acid upregulate involucrin and downregulate suprabasal keratin 10 in autocrine cultures of human epidermal keratinocytes.
abstract: Autocrine growth of human epidermal keratinocytes is initiated in subconfluent cell cultures in the absence of exogenous growth factors, at low calcium concentration of the medium and with sufficient cell density. Culture confluence inhibits keratinocyte proliferation and upregulates expression of early, keratin 10 (K10), and late, involucrin, markers of differentiation. In this report, the phenotype of autocrine keratinocytes was studied at high cell density (postconfluence), specifically after treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA), or all-trans retinoic acid (RA). At postconfluence, K10 is decreased but not involucrin. TPA upregulates involucrin expression, but not K10 in subconfluent keratinocytes. Treatment of confluent keratinocytes with RA downregulates K10, but upregulates involucrin. This in vitro culture model, unlike others, simulates for the first time the in vivo effects of RA, a member of the retinoid family which potently modulates keratinocyte differentiation and the expression of selected gene products. It thus can be developed to further examine epidermal differentiation.
authors.affiliation: Département Histologie-Embryologie, Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium.
authors.forename: Y
authors.initials: Y
authors.lastname: Poumay
authors.forename: F
authors.initials: F
authors.lastname: Herphelin
authors.forename: P
authors.initials: P
authors.lastname: Smits
authors.forename: I Y
authors.initials: IY
authors.lastname: De Potter
authors.forename: M R
authors.initials: MR
authors.lastname: Pittelkow
mesh_terms: D015415:Biomarkers; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D000078404:Epidermal Cells; D006801:Humans; D053550:Keratin-10; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007633:Keratins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D011498:Protein Precursors / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology*; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; C507493:KRT10 protein, human; D011498:Protein Precursors; D053550:Keratin-10; D014212:Tretinoin; C032253:involucrin; D007633:Keratins; D013755:Tetradecanoylphorbol Acetate