title: A preliminary examination of the role of NFAT 3 in human skin, cultured keratocytes and dermal fibroblasts.
abstract: BACKGROUND
  Ciclosporin A (CsA) is widely utilized for the treatment of inflammatory skin diseases such as psoriasis.The therapeutic effects of CsA are thought to be mediated via its immunosuppressive action on infiltrating lymphocytes in skin lesions. CsA and tacrolimus block T cell activation by inhibiting the phosphatase calcineurin and preventing translocation from the cytoplasm to the nucleus of the transcription factor Nuclear Factor of Activated T cells (NFAT).
  
  
  METHODS
  RT-PCR and Western Analysis were used to investigate the presence of NFAT-3 mRNA and protein in human keratocytes. Tissue culture of human keratocytes and immunostaining of cells on coverslips and confocal microscopy were used to assess the degree of nuclear localisation of NFAT-3 in cultured cells. Keratome biopsies were taken from patients with psoriasis (lesional and non-lesional skin) and normal skin and immunohistochemistry was used to assess the NFAT-3 localisation in these biopsies using a well characterized anti-NFAT-3 antibody.
  
  
  RESULTS
  The NFAT-3 mRNA and protein expression was demonstrated using RT-PCR and Western blotting. The expression of NFAT-3 in human keratocytes and response to different agonists provides perhaps a unique opportunity to examine the regulation, subcellular localization and kinetics of translocation of different NFATs in primary cultured human cells. As with NFAT 1, NFAT 2 and recently NFAT 5, differentiation-promoting agents that increase intracellular calcium concentration induced nuclear translocation of NFAT-3 in cultured keratocytes but with different kinetics.
  
  
  CONCLUSIONS
  These data provide the first evidence of that NFAT-3 is expressed in normal skin, psoriasis and that NFAT-3 functionally active in human keratocytes and that nuclear translocation of NFAT-3 in human skin cells has different kinetics than NFAT 1 suggesting that NFAT-3 may play an important role in regulation of keratocytes proliferation and differentiation at a different stage. Inhibition of this pathway in human epidermal keratocytes many account, in part for the therapeutic effects of CsA and tacrolimus in skin disorders such as psoriasis.
authors.affiliation: Departments of Clinical Dermatology, Molecular Dermatology, Skin and Soft Tissue Tumour Pathology, Ain Shams University, Cairo, Egypt. waldaraji@aol.com [corrected]
authors.forename: Wael I
authors.initials: WI
authors.lastname: Al-Daraji
authors.forename: Senem
authors.initials: S
authors.lastname: Tugrul
authors.forename: Esther
authors.initials: E
authors.lastname: Dempsey
authors.forename: Bettina
authors.initials: B
authors.lastname: Zelger
authors.forename: Adel
authors.initials: A
authors.lastname: Abdellaoui
authors.forename: Richard
authors.initials: R
authors.lastname: Prescott
authors.forename: Bernhard
authors.initials: B
authors.lastname: Zelger
mesh_terms: D065095:Calcineurin Inhibitors; D020013:Calcium Signaling; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology; D020405:Dermis / Q000166:cytology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D018613:Microscopy, Confocal; D050778:NFATC Transcription Factors / Q000235:genetics / Q000378:metabolism*; D011565:Psoriasis / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D012867:Skin / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D016559:Tacrolimus / Q000494:pharmacology
chemical_list: D065095:Calcineurin Inhibitors; D007166:Immunosuppressive Agents; D050778:NFATC Transcription Factors; C494010:NFATC4 protein, human; D012333:RNA, Messenger; D016572:Cyclosporine; D016559:Tacrolimus