title: [Effect of dexamethasone on osteopontin expression in the lung tissue of asthmatic mice].
abstract: OBJECTIVE
  To study the correlation between airway inflammation and osteopontin (OPN) level in the lung tissue, and to study the effect of dexamethasone (DXM) on OPN expression.
  
  
  METHODS
  Fifty mice were randomly divided into 5 groups: normal control, ovalbumin (OVA)-challenged asthma groups (OVA inhalation for 1 week or 2 weeks) and DXM-treated asthma groups (DXM treatment for 1 week or 2 weeks). The mice were sensitized and challenged with OVA to prepare mouse model of acute asthma. Alterations of airway inflammation were observed by haematoxylin-eosin staining. Serum level of OVA-sIgE was evaluated using ELISA. OPN expression in the lung tissue was located and measured by immunohistochemistry and Western blot respectively. OPN mRNA level in the lung tissue was detected by real-time PCR.
  
  
  RESULTS
  The asthma groups showed more pathological changes in the airway than the normal control and the DXM-treated groups. Compared with the OVA-challenged 1 week group, the pathological alterations increased in the OVA-challenged 2 weeks group. The level of OVA-sIgE in serum increased in the asthma groups compared with the control and the DXM groups (P<0.01). Serum OVA-sIgE sevel increased more significantly in the OVA-challenged 2 weeks group compared with the OVA-challenged 1 week group (P<0.01). OPN protein and mRNA levels were significantly raised in the asthma groups compared with the normal control and the DXM groups (P<0.01), and both levels increased more significantly in the OVA-challenged 2 weeks group compared with the OVA-challenged 1 week group (P<0.01).
  
  
  CONCLUSIONS
  The increased OPN expression in the lung tissue is associated with more severe airway inflammation in asthmatic mice, suggesting that OPN may play an important role in the pathogenesis of asthma. DXM can alleviate airway inflammation possibly by inhibiting OPN production.
authors.affiliation: Department of Pediatric Respiratory Medicine, Shengjing Hospital of China Medical University, Shenyang 110004, China. shangyunx@sina.com.
authors.forename: Hai-Hui
authors.initials: HH
authors.lastname: Sun
authors.forename: Yun-Xiao
authors.initials: YX
authors.lastname: Shang
authors.forename: Nan
authors.initials: N
authors.lastname: Yang
mesh_terms: D000818:Animals; D001249:Asthma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D003907:Dexamethasone / Q000627:therapeutic use*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007073:Immunoglobulin E / Q000097:blood; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D053495:Osteopontin / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D010047:Ovalbumin / Q000276:immunology
chemical_list: D053495:Osteopontin; D007073:Immunoglobulin E; D003907:Dexamethasone; D010047:Ovalbumin