title: Mechanisms of IFN-γ-induced apoptosis of human skin keratinocytes in patients with atopic dermatitis.
abstract: BACKGROUND
  Enhanced apoptosis of keratinocytes is the main cause of eczema and spongiosis in patients with the common inflammatory skin disease atopic dermatitis (AD).
  
  
  OBJECTIVE
  The aim of the study was to investigate molecular mechanisms of AD-related apoptosis of keratinocytes.
  
  
  METHODS
  Primary keratinocytes isolated from patients with AD and healthy donors were used to study apoptosis by using annexin V/7-aminoactinomycin D staining. Illumina mRNA Expression BeadChips, quantitative RT-PCR, and immunofluorescence were used to study gene expression. In silico analysis of candidate genes was performed on genome-wide single nucleotide polymorphism data.
  
  
  RESULTS
  We demonstrate that keratinocytes of patients with AD exhibit increased IFN-γ-induced apoptosis compared with keratinocytes from healthy subjects. Further mRNA expression analyses revealed differential expression of apoptosis-related genes in AD keratinocytes and skin and the upregulation of immune system-related genes in skin biopsy specimens of chronic AD lesions. Three apoptosis-related genes (NOD2, DUSP1, and ADM) and 8 genes overexpressed in AD skin lesions (CCDC109B, CCL5, CCL8, IFI35, LYN, RAB31, IFITM1, and IFITM2) were induced by IFN-γ in primary keratinocytes. The protein expression of IFITM1, CCL5, and CCL8 was verified in AD skin. In line with the functional studies and AD-related mRNA expression changes, in silico analysis of genome-wide single nucleotide polymorphism data revealed evidence of an association between AD and genetic markers close to or within the IFITM cluster or RAB31, DUSP1, and ADM genes.
  
  
  CONCLUSIONS
  Our results demonstrate increased IFN-γ responses in skin of patients with AD and suggest involvement of multiple new apoptosis- and inflammation-related factors in the development of AD.
authors.affiliation: Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland. ana.rebane@siaf.uzh.ch
authors.forename: Ana
authors.initials: A
authors.lastname: Rebane
authors.forename: Maya
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Alar
authors.initials: A
authors.lastname: Aab
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Baurecht
authors.forename: Andrea
authors.initials: A
authors.lastname: Koreck
authors.forename: Maire
authors.initials: M
authors.lastname: Karelson
authors.forename: Kristi
authors.initials: K
authors.lastname: Abram
authors.forename: Tauno
authors.initials: T
authors.lastname: Metsalu
authors.forename: Maire
authors.initials: M
authors.lastname: Pihlap
authors.forename: Norbert
authors.initials: N
authors.lastname: Meyer
authors.forename: Regina
authors.initials: R
authors.lastname: Fölster-Holst
authors.forename: Nikoletta
authors.initials: N
authors.lastname: Nagy
authors.forename: Lajos
authors.initials: L
authors.lastname: Kemeny
authors.forename: Külli
authors.initials: K
authors.lastname: Kingo
authors.forename: Jaak
authors.initials: J
authors.lastname: Vilo
authors.forename: Thomas
authors.initials: T
authors.lastname: Illig
authors.forename: Mübeccel
authors.initials: M
authors.lastname: Akdis
authors.forename: Andre
authors.initials: A
authors.lastname: Franke
authors.forename: Natalija
authors.initials: N
authors.lastname: Novak
authors.forename: Stephan
authors.initials: S
authors.lastname: Weidinger
authors.forename: Cezmi A
authors.initials: CA
authors.lastname: Akdis
mesh_terms: D053607:Adrenomedullin / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D000368:Aged; D000943:Antigens, Differentiation / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D001706:Biopsy; D002478:Cells, Cultured; D018946:Chemokine CCL5 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D054412:Chemokine CCL8 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D019295:Computational Biology; D003876:Dermatitis, Atopic / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D054638:Dual Specificity Phosphatase 1 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D005819:Genetic Markers / Q000235:genetics; D055106:Genome-Wide Association Study; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology* / Q000494:pharmacology; D015603:Keratinocytes / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D012867:Skin / Q000473:pathology*; D015854:Up-Regulation / Q000276:immunology
chemical_list: C507862:ADM protein, human; D000943:Antigens, Differentiation; D018946:Chemokine CCL5; D054412:Chemokine CCL8; D005819:Genetic Markers; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; C062010:leu-13 antigen; D053607:Adrenomedullin; D007371:Interferon-gamma; C517019:DUSP1 protein, human; D054638:Dual Specificity Phosphatase 1