title: Up-regulation of interleukin-13 receptor alpha1 on human keratinocytes in the skin of psoriasis and atopic dermatitis.
abstract: BACKGROUND
  Interleukin (IL)-13 is a pleiotropic cytokine, which shares many biological functions with IL-4. The receptor subunits of IL-13 consist of IL-4Ralpha, IL-13Ralpha1 and IL-13Ralpha2. The regulatory mechanisms of the IL-13Ralpha expression in the keratinocytes of certain skin disease have not been known.
  
  
  OBJECTIVE
  To clear the roles of IL-13 and the regulatory mechanisms of its receptor in atopic dermatitis (AD) and psoriasis.
  
  
  METHODS
  The expression of IL-13Ralpha1 in the skin of AD and psoriasis was investigated by immunohistochemistry. The regulation of IL-13Ralpha mRNA in the skin and human primary keratinocyte (HPK) was investigated by quantitative PCR. The secretion of IL-6 and RANTES from HPK was measured by ELISA.
  
  
  RESULTS
  The expression of IL-13Ralpha1 was more prominent on the suprabasal keratinocytes in the skin of AD and striking increase of staining was observed on all layers of keratinocyte in the skin of psoriasis. The mRNA of IL-13Ralpha1, but not of IL-13Ralpha2 was overexpressed in both skin of AD and psoriasis. In vitro experiment using HPK demonstrated that IFN-gamma, IL-13 but not IL-4 could up-regulate the mRNA expression of IL-13Ralpha1. In contrast, IL-13Ralpha2 mRNA expression was up-regulated by IFN-gamma plus IL-4. Furthermore, the stimulation of HPK with IFN-gamma plus IL-13 and/or IL-4 resulted in significant enhancement of IL-6 and RANTES secretion.
  
  
  CONCLUSIONS
  These findings indicate that IL-4 and IL-13 have different regulatory effects on the expression of IL-13Ralpha1 and alpha2, and the overexpression of IL-13Ralpha1 may play some roles in the pathogenesis of chronic stage of AD or psoriasis.
authors.affiliation: Department of Dermatology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Jongkonnee
authors.initials: J
authors.lastname: Wongpiyabovorn
authors.forename: Hajime
authors.initials: H
authors.lastname: Suto
authors.forename: Hiroko
authors.initials: H
authors.lastname: Ushio
authors.forename: Kenji
authors.initials: K
authors.lastname: Izuhara
authors.forename: Koichi
authors.initials: K
authors.lastname: Mitsuishi
authors.forename: Shigaku
authors.initials: S
authors.lastname: Ikeda
authors.forename: Atsuhito
authors.initials: A
authors.lastname: Nakao
authors.forename: Ko
authors.initials: K
authors.lastname: Okumura
authors.forename: Hideoki
authors.initials: H
authors.lastname: Ogawa
mesh_terms: D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D003876:Dermatitis, Atopic / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D018836:Inflammation Mediators / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology; D018793:Interleukin-13 / Q000494:pharmacology; D053661:Interleukin-13 Receptor alpha1 Subunit; D015847:Interleukin-4 / Q000494:pharmacology; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011565:Psoriasis / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D018123:Receptors, Interleukin / Q000235:genetics / Q000378:metabolism*; D053660:Receptors, Interleukin-13; D012867:Skin / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D016207:Cytokines; C508181:IL13RA1 protein, human; D018836:Inflammation Mediators; D018793:Interleukin-13; D053661:Interleukin-13 Receptor alpha1 Subunit; D020033:Protein Isoforms; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D053660:Receptors, Interleukin-13; D015847:Interleukin-4; D007371:Interferon-gamma