title: Aldehyde dehydrogenase 1A3 is transcriptionally activated by all-trans-retinoic acid in human epidermal keratinocytes.
abstract: Retinoids are regulators of keratinocyte differentiation in the epidermis and important therapeutics in dermatology. The formation of the most active retinoid, all-trans-retinoic acid (RA) by oxidation of retinal is catalyzed by aldehyde dehydrogenases (ALDH), of which ALDH1A3 has been shown to be most efficient. Here we investigated the expression of ALDH1A3 in epidermal cultures. Three alternatively spliced mRNAs of ALDH1A3 were detected in skin cultures with the conventionally spliced mRNA being predominant. Among a panel of ALDH genes, only ALDH1A3 was upregulated by RA in primary keratinocytes. RA increased the expression of ALDH1A3 also in organotypic human skin cultures and in an epidermal explant in vitro whereas no upregulation was detected in dermal fibroblasts and HeLa cells. Our results indicate that the regulation of the retinoic acid metabolism in the epidermis involves transcriptional activation of ALDH1A3, possibly representing a positive feedback loop, which enhances the effect of exogenous RA.
authors: Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
authors: Ulrich
authors: U
authors: Koenig
authors: Stefan
authors: S
authors: Amatschek
authors: Michael
authors: M
authors: Mildner
authors: Leopold
authors: L
authors: Eckhart
authors: Erwin
authors: E
authors: Tschachler
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000235:genetics*; D002478:Cells, Cultured; D000078404:Epidermal Cells; D004817:Epidermis / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000201:enzymology*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014212:Tretinoin / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D014212:Tretinoin; D000444:Aldehyde Dehydrogenase