title: [Dynamic expression of E2F1 in lung of premature rats with hyperoxia-induced chronic lung disease and its significance].
abstract: OBJECTIVE
  To determine the dynamic expression of E2F1 in lung of premature rats with hyperoxia-induced chronic lung disease and the relation between E2F1 and pulmonary fibrosis.
  
  
  METHODS
  Premature Wistar rats at 21 days gestation were randomly and equally divided into a hyperoxia group and a room air group. The hyperoxia group was continuously exposed to hyperoxia (90%) while the air group in room air. Lung tissues in the 2 groups were obtained at 3, 7 and 14 days after exposing to either room air or hyperoxia. The changes of pulmonary histopathology at different time points were observed by hematoxylin and eosin staining; the severity of pulmonary fibrosis was evaluated; and the expression of E2F1 in lung tissue was detected by immunohistochemistry and Western blot.
  
  
  RESULTS
  After 3 days of hyperoxia, no significant interstitial fibrosis was observed; while after 7 days in the hyperoxia group, interstitial fibrosis was observed. These changes became more obvious after 14 days of prolonged hyperoxia exposure. No significant difference in the expressions of E2F1 protein was found between the hyperoxia group and the room air group 3 days postnatally (P>0.05). The expression of E2F1 in the hyperoxia group significantly increased 7 days and 14 days postnatally (P<0.05, P<0.01).
  
  
  CONCLUSIONS
  Abnormality of E2F1 expression is involved in the pathological process of the proliferation of lung fibroblasts in hyperoxia-induced chronic lung disease neonatal rats, and it plays an important role in lung fibrosis.
authors.affiliation: Department of Neonates, China Medical University, Shenyang, China.
authors.forename: Shimeng
authors.initials: S
authors.lastname: Zhao
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.forename: Hongmin
authors.initials: H
authors.lastname: Wu
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D050687:E2F1 Transcription Factor / Q000378:metabolism*; D018496:Hyperoxia / Q000378:metabolism* / Q000473:pathology; D007150:Immunohistochemistry; D008168:Lung / Q000473:pathology*; D008171:Lung Diseases / Q000378:metabolism* / Q000473:pathology; D011658:Pulmonary Fibrosis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar
chemical_list: D050687:E2F1 Transcription Factor; C493755:E2f1 protein, rat