title: Quantification of tyrosinase, TRP-1, and Trp-2 transcripts in human melanocytes by reverse transcriptase-competitive multiplex PCR--regulation by steroid hormones.
abstract: We have introduced a reverse transcriptase polymerase chain reaction based method to measure mRNA levels of the melanogenesis enzymes tyrosinase, tyrosinase-related-protein 1 (TRP-1), and tyrosinase-related-protein 2 (TRP-2). Expression was determined by reverse transcriptase-competitive multiplex polymerase chain reaction of (i) melanogenesis enzyme transcripts and the "housekeeping" gene glyceraldehyde-3-phosphate dehydrogenase, and (ii) two internal standards consisting of mutated melanogenesis enzyme cDNA and mutated gene glyceraldehyde-3-phosphate dehydrogenase cDNA. This was investigated on in vitro cultured melanocytes in the presence of three different steroids; one glucocorticoid (betamethasone-17-valerate) and two sex steroids (diethylstilbestrol and estradiol). All three steroids lead to an increase of about 1.5-2.5-fold of tyrosinase transcripts. The amount of TRP-1 transcripts was likewise enhanced, but only moderately (approximately 1.5-fold). In contrast, TRP-2 transcripts were reduced by approximately 40% in number after betamethasone-17-valerate treatment, whereas the two sex steroids, diethylstilbestrol and estradiol, caused an upregulation of about 20-fold of the initial TRP-2 transcript level. We therefore suggest that hyperpigmentation during pregnancy or under contraceptive treatment is mediated by a direct induction of melanogenesis via sex steroids.
authors.affiliation: Department of Dermatology, Klinikum der Johann Wolfgang, Goethe Univesität, Frankfurt/Main, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Kippenberger
authors.forename: S
authors.initials: S
authors.lastname: Loitsch
authors.forename: F
authors.initials: F
authors.lastname: Solano
authors.forename: A
authors.initials: A
authors.lastname: Bernd
authors.forename: R
authors.initials: R
authors.lastname: Kaufmann
mesh_terms: D001623:Betamethasone / Q000494:pharmacology; D002460:Cell Line; D004054:Diethylstilbestrol / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology*; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000235:genetics*; D008544:Melanocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008562:Membrane Glycoproteins; D014442:Monophenol Monooxygenase / Q000235:genetics*; D010088:Oxidoreductases; D016133:Polymerase Chain Reaction / Q000379:methods; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D006728:Hormones; D008562:Membrane Glycoproteins; D011506:Proteins; D012333:RNA, Messenger; D004958:Estradiol; D004054:Diethylstilbestrol; D001623:Betamethasone; D010088:Oxidoreductases; C489799:TYRP1 protein, human; C064056:tyrosinase-related protein-1; D014442:Monophenol Monooxygenase; D019746:Intramolecular Oxidoreductases; C042501:dopachrome isomerase