In situ detection of retinoid-X receptor expression in normal and psoriatic human skin.
Increasing evidence suggests that the retinoid-X receptors RXR(-alpha,-beta,-gamma) play a crucial part in regulating the transcriptional activity of several steroid hormone receptors, including 1,25-dihydroxyvitamin D3 receptors (VDR) and retinoic acid receptors (RAR-alpha,-beta,-gamma). We developed a new technique for immunohistochemical in situ detection of RXR receptors, and investigated the localization of RXR-alpha in normal and psoriatic human skin using a recently raised corresponding specific antibody. RXR-alpha positive cells related to the skin were phenotyped by sequential sections and a double-labelling procedure for the simultaneous demonstration of this nuclear receptor and cell membrane antigens, as well as cytokeratin 10, HLA-DR and vimentin. Our findings indicate that: (i) RXR-alpha is strongly expressed in normal and psoriatic human skin; (ii) most of the cell types in normal human skin, including keratinocytes, melanocytes, fibroblasts and skin immune cells such as Langerhans cells, reveal strong nuclear immunoreactivity for RXR-alpha, with less cytoplasmic staining; (iii) altered levels or distribution of RXR-alpha in the skin do not appear to be involved in the genesis of psoriasis vulgaris, but subepidermal and subcellular distribution suggest a function of RXR-alpha in the transition from proliferation to differentiation in epidermal keratinocytes; (iv) expression in the hair follicle points to a contribution from RXR-alpha to hair growth.
Reichrath
J
J
Department of Dermatology, Universität des Saarlandes, Homburg, Germany.
Münssinger
T
T
Kerber
A
A
Rochette-Egly
C
C
Chambon
P
P
Bahmer
F A
FA
Baum
H P
HP
D000328:Adult; D000818:Animals; D004817:Epidermis / Q000737:chemistry; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D015603:Keratinocytes / Q000737:chemistry; D007633:Keratins / Q000032:analysis; D008297:Male; D051379:Mice; D009687:Nuclear Proteins / Q000032:analysis*; D011565:Psoriasis / Q000378:metabolism*; D018168:Receptors, Retinoic Acid / Q000032:analysis*; D047488:Retinoid X Receptors; D012627:Sebaceous Glands / Q000737:chemistry; D012867:Skin / Q000737:chemistry*; D014157:Transcription Factors / Q000032:analysis*; D014746:Vimentin / Q000032:analysis
D006684:HLA-DR Antigens; D009687:Nuclear Proteins; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D014157:Transcription Factors; D014746:Vimentin; D007633:Keratins