title: Ribosomal protein S6 is hyperactivated and differentially phosphorylated in epidermal lesions of patients with psoriasis and atopic dermatitis.
abstract: BACKGROUND
  The ribosomal protein S6 is part of the translation machinery and is activated by phosphorylation via the mammalian target of rapamycin pathway, which is activated in psoriatic skin.
  
  
  OBJECTIVE
  To investigate which S6 sites are phosphorylated in psoriasis and atopic dermatitis (AD), and to study whether S6 phosphorylation is associated with inflammation and/or keratinocyte hyperproliferation.
  
  
  METHODS
  Healthy skin and skin lesions of patients with psoriasis and AD were investigated by immunostaining using antibodies that stain proliferating cells, leucocytes and distinct phosphorylated sites of S6.
  
  
  RESULTS
  All psoriasis and AD lesions revealed abnormal S6 phosphorylation in the epidermis. The extent of S6 phosphorylation was diverse, generally stronger in psoriasis and correlated, in both diseases, with inflammation. S6 showed differential phosphorylation in distinct epidermal layers, which was most pronounced in hyperproliferative regions.
  
  
  CONCLUSIONS
  Differential S6 phosphorylation may have a role in abnormal keratinocyte proliferation/differentiation.
authors.affiliation: Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: M T
authors.initials: MT
authors.lastname: Ruf
authors.forename: A
authors.initials: A
authors.lastname: Andreoli
authors.forename: P
authors.initials: P
authors.lastname: Itin
authors.forename: G
authors.initials: G
authors.lastname: Pluschke
authors.forename: P
authors.initials: P
authors.lastname: Schmid
mesh_terms: D016022:Case-Control Studies; D003876:Dermatitis, Atopic / Q000378:metabolism*; D004817:Epidermis / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D010766:Phosphorylation / Q000502:physiology; D011565:Psoriasis / Q000378:metabolism*; D038601:Ribosomal Protein S6 / Q000378:metabolism*
chemical_list: D038601:Ribosomal Protein S6