title: Psoriasin (S100A7), an antimicrobial peptide, is increased in human middle ear cholesteatoma.
abstract: CONCLUSIONS
  Increased psoriasin in cholesteatoma epithelium may play a role in epithelial inflammatory response and differentiation.
  
  
  OBJECTIVE
  Cholesteatoma is characterized by excessive keratinocyte differentiation leading to inflammation, granulation tissue, and osteolytic activity. Moreover, psoriasin may act as an antimicrobial peptide, stimulate granulocytes, and control keratinocyte differentiation. The purpose of this study was to investigate the differential expression patterns and the localization of psoriasin in cholesteatoma and in normal external auditory canal skin.
  
  
  METHODS
  Expression levels of psoriasin mRNA were evaluated by real-time PCR and Western blotting. Cholesteatoma-affected and normal external auditory canal skin samples were immunostained with monoclonal antibody to psoriasin. Localization of immunoreactivity to psoriasin antibody was then compared.
  
  
  RESULTS
  By real-time PCR, expression levels of psoriasin mRNA in cholesteatoma were significantly higher than in normal external auditory canal skin, and this was confirmed by Western blotting. Immunohistochemical staining revealed that psoriasin protein is mainly expressed in the granular layer and in the upper parts of the spinous layer in cholesteatoma epithelium, but that it is expressed in the superficial layer of normal external auditory canal skin.
authors.affiliation: Department of Otolaryngology, Pundang Jesaeng Hospital, Daejin Medical Center, Seongnam.
authors.forename: Ki Hyung
authors.initials: KH
authors.lastname: Kim
authors.forename: Jae-Gu
authors.initials: JG
authors.lastname: Cho
authors.forename: Jae-Jun
authors.initials: JJ
authors.lastname: Song
authors.forename: Jeong-Soo
authors.initials: JS
authors.lastname: Woo
authors.forename: Heung-Man
authors.initials: HM
authors.lastname: Lee
authors.forename: Hak Hyun
authors.initials: HH
authors.lastname: Jung
authors.forename: Soon-Jae
authors.initials: SJ
authors.lastname: Hwang
authors.forename: Sungwon
authors.initials: S
authors.lastname: Chae
mesh_terms: D015153:Blotting, Western; D018424:Cholesteatoma, Middle Ear / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000075023:S100 Calcium Binding Protein A7; D009418:S100 Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D000075023:S100 Calcium Binding Protein A7; D009418:S100 Proteins; C089242:S100A7 protein, human