title: Is MC1 dispensable for regulation of cutaneous inflammatory and immune responses?
abstract: The melanocortin-1 receptor (MC1 ) - being most abundantly expressed in the skin by melanocytes - has a physiological role for melanin pigmentation in many vertebrate species. MC1 has also been implicated in regulation of skin inflammation as this receptor is detectable in the majority of non-melanocytic cell types and its ligand α-melanocyte-stimulating hormone (α-MSH) exerts immunoregulatory and anti-inflammatory effects. However, in vivo studies on mice with targeted disruption of MC1 have been missing in the context of skin inflammation until recently. Wolnicka-Glubisz et al. now reported that the course of ultraviolet (UV)-induced inflammation, contact hypersensitivity, neonatal immune tolerance and UV-induced immunosuppression is similar in MC1 signal-deficient (C57BL/6-Mc1r(e/e)) and wild-type mice. These unexpected findings are supported by own observations in experimentally induced immune-complex-mediated vasculitis: Mc1r(e/e) mice exhibited a similar extent of the reverse passive cutaneous Arthus reaction compared with wild-type animals. Future studies are thus needed to clarify whether these findings are due to limitations in the chosen mouse model and/or point to additional MC subtypes that may regulate inflammatory and immune responses in the skin.
authors.affiliation: Department of Dermatology, Laboratory for Neuroendocrinology of the Skin and Interdisciplinary Endocrinology, University of Münster, Münster, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Böhm
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Luger
authors.forename: Annika K
authors.initials: AK
authors.lastname: Steingräber
authors.forename: Tobias
authors.initials: T
authors.lastname: Goerge
mesh_terms: D000818:Animals; D007249:Inflammation / Q000209:etiology* / Q000503:physiopathology*; D044102:Receptor, Melanocortin, Type 1 / Q000502:physiology*; D012867:Skin / Q000503:physiopathology* / Q000528:radiation effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D044102:Receptor, Melanocortin, Type 1
keywords: MC1; MSH; immune response; immunomodulation; vasculitis