title: Expression of bone morphogenetic protein 2, 4, 5, and 7 correlates with histological activity of otosclerotic foci.
abstract: CONCLUSIONS
  This study is the first to establish that bone morphogenetic protein 5 (BMP5) plays a role in the pathogenesis of otosclerosis. These results confirm that elevated expression levels of BMPs, members of the transforming growth factor (TGF)-β superfamily, contribute to the pathologically increased bone turnover in early, active stages of otosclerosis.
  
  
  OBJECTIVE
  Otosclerosis is a complex bone remodeling disorder of the otic capsule, which might be characterized by increased expression of different types of BMPs. TGF-β and BMP are both members of the TGF-β superfamily and play a critical role in bone resorption and new bone formation. It has been suggested that BMP and its receptors may be involved in the pathologically increased bone turnover observed in otosclerosis.
  
  
  METHODS
  Fifty-one otosclerotic and 16 non-otosclerotic ankylotic stapes footplates were histologically analyzed: conventional hematoxylin-eosin staining and BMP2, 4, 5, and 7specific immunofluorescent assays were performed. Cortical bone fragments (n = 35) and incus specimens (n = 6) were used as negative controls.
  
  
  RESULTS
  Active otosclerosis (n = 39) was characterized by increased expression of BMP2, 4, 5, and 7. Inactive cases of otosclerosis (n = 12) were characterized by negative immunoreaction for BMPs. Non-otosclerotic stapes specimens (n = 16) and negative controls (n = 41) showed negligible BMP expression. The BMP expression pattern showed a strong correlation with the histological activity of otosclerosis.
authors.affiliation: Department of Otolaryngology and Head and Neck Surgery, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Csomor
authors.forename: Balázs
authors.initials: B
authors.lastname: Liktor
authors.forename: Bálint
authors.initials: B
authors.lastname: Liktor
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Szekanecz
authors.forename: István
authors.initials: I
authors.lastname: Sziklai
authors.forename: Tamás
authors.initials: T
authors.lastname: Karosi
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000096:biosynthesis*; D055415:Bone Morphogenetic Protein 4 / Q000096:biosynthesis*; D055417:Bone Morphogenetic Protein 5 / Q000096:biosynthesis*; D055419:Bone Morphogenetic Protein 7 / Q000096:biosynthesis*; D016723:Bone Remodeling / Q000502:physiology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010040:Otosclerosis / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D011379:Prognosis; D013199:Stapes / Q000378:metabolism / Q000473:pathology*; D013201:Stapes Surgery
chemical_list: C525718:BMP2 protein, human; C525809:BMP4 protein, human; C525814:BMP5 protein, human; C525819:BMP7 protein, human; D015415:Biomarkers; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D055417:Bone Morphogenetic Protein 5; D055419:Bone Morphogenetic Protein 7