title: The expression of osteopontin and its association with Clara cell 10 kDa protein in allergic rhinitis.
abstract: BACKGROUND
  Osteopontin (OPN) is a multifunctional protein that has recently been linked to allergic diseases. Clara cell 10 kDa protein (CC10) is another protein linked to allergy, and has been suggested to have an inhibitory role in inflammatory airway diseases. At this time, it is not known whether OPN is involved in allergic rhinitis (AR) or if there is any association between CC10 and OPN in AR.
  
  
  OBJECTIVE
  To study the expression of OPN and its potential association with CC10 in AR.
  
  
  METHODS
  The expression of CC10 and OPN in nasal mucosa of AR patients was investigated. AR animal models were established by using wild-type and CC10-knockout mice. In some experiments, human recombinant CC10 protein was given to AR mice during either sensitization or challenge. The phenotypic changes were examined by histology and real-time RT-PCR. The direct effect of CC10 on the OPN expression in spleen mononuclear cells and on the OPN-induced inflammatory cytokine expression in BEAS-2B cells was measured through in vitro cell culture.
  
  
  RESULTS
  OPN expression was up-regulated, with a concomitant down-regulation of CC10, in AR patients, showing a significant negative correlation between their expression. Compared with control mice sensitized with PBS, the OPN expression was significantly increased in AR mice; such an increase was more prominent in CC10-knockout mice, compared with wild-type. Administration of CC10 during both sensitization and challenge could markedly ameliorate Th2-skewed inflammation and OPN expression in nasal mucosa. CC10 administration at the sensitization phase could also reduce spleen OPN expression. The in vitro study showed that CC10 directly down-regulated the OPN expression in spleen mononuclear cells stimulated with OVA and suppressed the OPN-induced expression of Th2 cytokines and pro-inflammatory cytokines in BEAS-2B cells.
  
  
  CONCLUSIONS
  In the context of allergic airway responses, CC10 can inhibit OPN expression and suppress the Th2-promoting function of OPN, resulting in CC10's inhibitory biological effects.
authors.affiliation: Departments of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: X
authors.initials: X
authors.lastname: Lu
authors.forename: H-J
authors.initials: HJ
authors.lastname: Yu
authors.forename: X-Y
authors.initials: XY
authors.lastname: Hua
authors.forename: Y-H
authors.initials: YH
authors.lastname: Cui
authors.forename: S-K
authors.initials: SK
authors.lastname: Huang
authors.forename: Z
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000328:Adult; D000818:Animals; D016022:Case-Control Studies; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008875:Middle Aged; D009297:Nasal Mucosa / Q000276:immunology / Q000378:metabolism; D053495:Osteopontin / Q000235:genetics / Q000378:metabolism*; D010047:Ovalbumin; D039981:Pyroglyphidae / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000008:administration & dosage; D020545:Respiratory Mucosa / Q000276:immunology / Q000378:metabolism*; D012221:Rhinitis, Allergic, Perennial / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D013154:Spleen / Q000276:immunology / Q000378:metabolism; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism; D014598:Uteroglobin / Q000008:administration & dosage / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D012333:RNA, Messenger; D011994:Recombinant Proteins; C556389:SCGB1A1 protein, human; C506895:SPP1 protein, human; C556390:Scgb1a1 protein, mouse; C506896:Spp1 protein, mouse; D053495:Osteopontin; D010047:Ovalbumin; D014598:Uteroglobin