title: Interleukin-33 affects cytokine production by keratinocytes in vitiligo.
abstract: BACKGROUND
  Vitiligo is an acquired skin pigmentation disorder. Interleukin (IL)-33 is a newly described member of the IL-1 family.
  
  
  OBJECTIVE
  To examine the role of IL-33 and its regulation in vitiligo.
  
  
  METHODS
  Expression of IL-33 and its receptor (interleukin 1 receptor-like 1 protein; also known as ST2), in skin biopsies taken from healthy subjects and patients with vitiligo, was examined by immunofluorescence staining and western blotting. IL-33 secretion from primary keratinocytes was measured by ELISA. IL-33-stimulated release of stem cell factor (SCF), basic fibroblast growth factor (bFGF), IL-6 and tumour necrosis factor (TNF)-α from primary keratinocytes was examined by ELISA.
  
  
  RESULTS
  IL-33 and ST2 expression was increased in lesional skin, and serum IL-33 was raised in patients with vitiligo. IL-33 expression moved from the nucleus to the cytoplasm of keratinocytes. IL-33 reduced expression of both SCF and bFGF, but increased expression of both IL-6 and TNF-α expression in primary keratinocytes.
  
  
  CONCLUSIONS
  IL-33 is secreted by keratinocytes and functions as an alarmin. It may induce melanocyte death by regulating cytokines in the cellular microenvironment.
authors.affiliation: Center for Translational Medicine, College of Medicine, First Affiliated Hospital Xi'an Jiaotong University, Xi'an, China.
authors.forename: P
authors.initials: P
authors.lastname: Li
authors.forename: H
authors.initials: H
authors.lastname: Ma
authors.forename: D
authors.initials: D
authors.lastname: Han
authors.forename: K
authors.initials: K
authors.lastname: Mou
mesh_terms: D000328:Adult; D015153:Blotting, Western; D016022:Case-Control Studies; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005346:Fibroblast Growth Factors / Q000378:metabolism; D006801:Humans; D000067596:Interleukin-33; D015850:Interleukin-6 / Q000378:metabolism; D007378:Interleukins / Q000378:metabolism* / Q000502:physiology; D015603:Keratinocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D019089:Stem Cell Factor / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014820:Vitiligo / Q000378:metabolism*
chemical_list: C506536:IL33 protein, human; D000067596:Interleukin-33; D015850:Interleukin-6; D007378:Interleukins; D019089:Stem Cell Factor; D014409:Tumor Necrosis Factor-alpha; D005346:Fibroblast Growth Factors