title: Transcriptional regulators of steroidogenesis, DAX-1 and SF-1, are expressed in human skin.
abstract: DAX-1 and SF-1 are members of the orphan nuclear receptor superfamily that are critical regulatory components of the hypothalamic-pituitary-adrenal-gonadal axis. In adrenal and gonadal tissues they regulate the expression of the cytochrome P450 steroid hydroxylase genes, key mediators of steroidogenesis. The identification of a number of steroid hydroxylases in human skin prompted us to investigate the presence of DAX-1 and SF-1. Immuno histochemical analysis of human skin revealed a distinctive staining pattern for DAX-1 and SF-1 in skin and its appendages. Prominent staining for DAX-1 was confined to the epidermis, sebaceous glands, sweat glands, and outer root sheath of the hair follicle with weaker expression in the inner root sheath, matrix cells, and dermal papilla cells. Similarly, SF-1 was also detected in the epidermis but displayed a scattered nuclear pattern across all layers. SF-1 immunoreactivity was also detected in the exocrine glands and was stronger than DAX-1 in the inner root sheath, matrix cells, and dermal papilla cells. Co-localization of DAX-1 and SF-1 was demonstrated by immunocytochemistry in the HaCaT keratinocyte cell line, primary keratinocytes, preadipocytes, and dermal papilla cells. Reverse transcriptase-polymerase chain reaction analysis demonstrated the expression of DAX-1 and SF-1 mRNA in whole human skin and Western analysis also confirmed the presence of DAX-1 protein in skin-derived cells. Our investigations demonstrate that two important regulators of steroidogeneisis are present in human skin and its appendages. These transcription factors may have a role in cutaneous steroidogenesis and thus be involved in hair follicle cycling or pathologies associated with steroids. Further studies are needed to determine the functional roles of DAX-1 and SF-1 in human skin.
authors.affiliation: Center for Cutaneous Research, St. Bartholomew's & the Royal London School of Medicine & Dentistry, Queen Mary, University of London, London, UK.
authors.forename: M V
authors.initials: MV
authors.lastname: Patel
authors.forename: I A
authors.initials: IA
authors.lastname: McKay
authors.forename: J M
authors.initials: JM
authors.lastname: Burrin
mesh_terms: D016475:3T3 Cells; D000818:Animals; D015153:Blotting, Western; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics*; D000078404:Epidermal Cells; D004817:Epidermis / Q000737:chemistry / Q000502:physiology*; D051717:Fushi Tarazu Transcription Factors; D015870:Gene Expression / Q000502:physiology; D018859:Hair Follicle / Q000737:chemistry / Q000166:cytology / Q000502:physiology; D018398:Homeodomain Proteins; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000166:cytology / Q000502:physiology; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid / Q000032:analysis / Q000235:genetics*; D012097:Repressor Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054339:Steroidogenic Factor 1; D013545:Sweat Glands / Q000737:chemistry / Q000166:cytology / Q000502:physiology; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics*
chemical_list: D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; C539965:NR0B1 protein, human; C539966:Nr0b1 protein, mouse; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D012097:Repressor Proteins; D054339:Steroidogenic Factor 1; D014157:Transcription Factors