title: Genetic ablation of mast cells redefines the role of mast cells in skin wound healing and bleomycin-induced fibrosis.
abstract: Conclusive evidence for the impact of mast cells (MCs) in skin repair is still lacking. Studies in mice examining the role of MC function in the physiology and pathology of skin regenerative processes have obtained contradictory results. To clarify the specific role of MCs in regenerative conditions, here we used a recently developed genetic mouse model that allows conditional MC ablation to examine MC-specific functions in skin. This mouse model is based on the cell type-specific expression of Cre recombinase in connective tissue-type MCs under control of the Mcpt5 promoter and the Cre-inducible diphtheria toxin receptor-mediated cell lineage ablation by diphtheria toxin. In response to excisional skin injury, genetic ablation of MCs did not affect the kinetics of reepithelialization, the formation of vascularized granulation tissue, or scar formation. Furthermore, genetic ablation of MCs failed to prevent the development of skin fibrosis upon bleomycin challenge. The amount of deposited collagen and the biochemistry of collagen fibril crosslinks within fibrotic lesions were comparable in MC-depleted and control mice. Collectively, our findings strongly suggest that significant reduction of MC numbers does not affect skin wound healing and bleomycin-induced fibrosis in mice, and provide to our knowledge previously unreported insight in the long-debated contribution of MCs in skin regenerative processes.
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Willenborg
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany.
authors.forename: Beate
authors.initials: B
authors.lastname: Eckes
authors.affiliation: Department of Dermatology, University of Lübeck, Lübeck, Germany; Institute of Virology and Cell Biology, University of Lübeck, Lübeck, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Brinckmann
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Krieg
authors.affiliation: Institute for Molecular Medicine Mainz, University of Mainz, Mainz, Germany.
authors.forename: Ari
authors.initials: A
authors.lastname: Waisman
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Hartmann
authors.affiliation: Institute for Immunology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Roers
authors.affiliation: Department of Dermatology, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany. Electronic address: sabine.eming@uni-koeln.de.
authors.forename: Sabine A
authors.initials: SA
authors.lastname: Eming
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D001761:Bleomycin / Q000494:pharmacology; D004195:Disease Models, Animal; D005355:Fibrosis / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology; D006097:Granulation Tissue / Q000502:physiology; D015603:Keratinocytes / Q000473:pathology / Q000502:physiology; D007962:Leukocytes / Q000473:pathology / Q000502:physiology; D008407:Mast Cells / Q000473:pathology* / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D012871:Skin Diseases / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology; D014945:Wound Healing / Q000502:physiology*
chemical_list: D000903:Antibiotics, Antineoplastic; D001761:Bleomycin