title: Prolactin--a novel neuroendocrine regulator of human keratin expression in situ.
abstract: The controls of human keratin expression in situ remain to be fully elucidated. Here, we have investigated the effects of the neurohormone prolactin (PRL) on keratin expression in a physiologically and clinically relevant test system: organ-cultured normal human hair follicles (HFs). Not only do HFs express a wide range of keratins, but they are also a source and target of PRL. Microarray analysis revealed that PRL differentially regulated a defined subset of keratins and keratin-associated proteins. Quantitative immunohistomorphometry and quantitative PCR confirmed that PRL up-regulated expression of keratins K5 and K14 and the epithelial stem cell-associated keratins K15 and K19 in organ-cultured HFs and/or isolated HF keratinocytes. PRL also up-regulated K15 promoter activity and K15 protein expression in situ, whereas it inhibited K6 and K31 expression. These regulatory effects were reversed by a pure competitive PRL receptor antagonist. Antagonist alone also modulated keratin expression, suggesting that "tonic stimulation" by endogenous PRL is required for normal expression levels of selected keratins. Therefore, our study identifies PRL as a major, clinically relevant, novel neuroendocrine regulator of both human keratin expression and human epithelial stem cell biology in situ.
authors.affiliation: Department of Dermatology, University of Lübeck, Lübeck, Germany.
authors.forename: Yuval
authors.initials: Y
authors.lastname: Ramot
authors.forename: Tamás
authors.initials: T
authors.lastname: Bíró
authors.forename: Stephan
authors.initials: S
authors.lastname: Tiede
authors.forename: Balázs I
authors.initials: BI
authors.lastname: Tóth
authors.forename: Ewan A
authors.initials: EA
authors.lastname: Langan
authors.forename: Koji
authors.initials: K
authors.lastname: Sugawara
authors.forename: Kerstin
authors.initials: K
authors.lastname: Foitzik
authors.forename: Arieh
authors.initials: A
authors.lastname: Ingber
authors.forename: Vincent
authors.initials: V
authors.lastname: Goffin
authors.forename: Lutz
authors.initials: L
authors.lastname: Langbein
authors.forename: Ralf
authors.initials: R
authors.lastname: Paus
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism*; D015153:Blotting, Western; D005260:Female; D020869:Gene Expression Profiling; D018859:Hair Follicle / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism; D007633:Keratins / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D009924:Organ Culture Techniques; D011388:Prolactin / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D015415:Biomarkers; D012333:RNA, Messenger; D007633:Keratins; D011388:Prolactin