Solar-simulated ultraviolet radiation-induced upregulation of the melanocortin-1 receptor, proopiomelanocortin, and alpha-melanocyte-stimulating hormone in human epidermis in vivo.
Ultraviolet light is one of the most crucial environmental factors with regard to its capacity to induce skin cancer, premature aging of the skin, and immunosuppression. Although ultraviolet directly affects the function of epidermal cells, many of these effects are mediated by induction of cytokines, growth factors, and neuropeptides, such as alpha-melanocyte-stimulating hormone. Recently, in addition to its well-known pigmentation inducing activity, a strong anti-inflammatory as well as an immunomodulatory potential of alpha-melanocyte-stimulating hormone has been recognized. The aim of this study was to determine, whether ultraviolet irradiation affects the expression of both alpha-melanocyte-stimulating hormone and the melanocortin-1 receptor in human epidermis in vivo. The volar aspects of the forearms were exposed to twice the minimal erythema dose of solar-simulating radiation. Three, 6, and 24 h after irradiation, the proopiomelanocortin and interleukin-10 mRNA levels in suction blister induced epidermal sheets were considerably upregulated as detected by semiquantitative reverse transcription-polymerase chain reaction. Furthermore, alpha-melanocyte-stimulating hormone and interleukin-10 protein levels in blister fluids were significantly increased 24 h after ultraviolet irradiation, an effect that could be abolished by application of the broad-spectrum sunscreen Anthélios XL prior to ultraviolet (solar-simulating radiation) exposure. In addition, enhanced melanocortin-1 receptor mRNA and receptor protein expression upon solar-simulating radiation was ascertained by reverse transcription-polymerase chain reaction and immunohistochemistry of the epidermal sheets, respectively. Proopiomelanocortin-derived neuropeptides, such as alpha-melanocyte-stimulating hormone may therefore play an important part in modulating ultraviolet-induced inflammation.
Department of Dermatology and Ludwig Boltzmann Institute for Cell Biology and Immunobiology of the Skin, University of Münster, Muenster, Germany.
Meinhard
M
Schiller
Thomas
T
Brzoska
Markus
M
Böhm
Dieter
D
Metze
Thomas E
TE
Scholzen
André
A
Rougier
Thomas A
TA
Luger
D000293:Adolescent; D000328:Adult; D001768:Blister / Q000503:physiopathology; D004817:Epidermis / Q000502:physiology* / Q000528:radiation effects; D015870:Gene Expression / Q000528:radiation effects; D006801:Humans; D016753:Interleukin-10 / Q000235:genetics; D008875:Middle Aged; D011333:Pro-Opiomelanocortin / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D044102:Receptor, Melanocortin, Type 1 / Q000235:genetics*; D013472:Sunlight / Q000009:adverse effects; D013473:Sunscreening Agents / Q000008:administration & dosage; D014466:Ultraviolet Rays / Q000009:adverse effects*; D015854:Up-Regulation / Q000528:radiation effects; D000521:alpha-MSH / Q000378:metabolism*
D012333:RNA, Messenger; D044102:Receptor, Melanocortin, Type 1; D013473:Sunscreening Agents; D016753:Interleukin-10; D000521:alpha-MSH; D011333:Pro-Opiomelanocortin