title: [Relationship between expression of STAT3 gene and proliferation of rat pulmonary arterial smooth muscle cells under hypoxia conditions].
abstract: OBJECTIVE
  To explore the relationship between expression of signal transduction and activators of transcription 3 (STAT3) gene and proliferation of rat pulmonary arterial smooth muscle cells (PASMCs) under hypoxia conditions.
  
  
  METHODS
  After primarily cultured rat PASMCs was treated with AG490 and then exposed to hypoxia, the tyrosine-phosphorylated STAT3 protein were detected at 2 h, 6 h, 12 h, 16 h, 24 h of exposure to hypoxia by semi-quantitive RT-PCR (sqRT-PCR) and Western blot respectively. The expression of c-myc mRNA was analyzed by sqRT-PCR. 3H-TdR incorporation was used to detect the cell proliferation.
  
  
  RESULTS
  The level of tyrosine-phosphorylated STAT3 increased at 6 h and peaked at 12 h. The expression of c-myc mRNA increased after 2 h of hypoxia and reached maximal level at 4 h, then declined at 6 h and to the basal levels at 12 h. With the prolonging of hypoxia time, 3H-TdR incorporation in PASMC under hypoxia conditions was significantly higher. AG490 inhibited proliferation of PASMCs by preventing STAT3 tyrosine phosphorylation and the expression of c-myc under hypoxia conditions.
  
  
  CONCLUSIONS
  (1) The activation of STAT3 and c-myc gene might play an important role in the early stage of hypoxia-induced PASMCs proliferation. (2) STAT3 upregulated the expression of c-myc during the proliferation of PASMCs induced by hypoxia.
authors.affiliation: Institute of Respiratory Diseases, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors.forename: Li
authors.initials: L
authors.lastname: Bai
authors.forename: Zu-Bin
authors.initials: ZB
authors.lastname: Yu
authors.forename: Gui-Sheng
authors.initials: GS
authors.lastname: Qian
authors.forename: Shu-Ping
authors.initials: SP
authors.lastname: Li
mesh_terms: D000818:Animals; D015687:Cell Hypoxia; D049109:Cell Proliferation; D002478:Cells, Cultured; D000860:Hypoxia / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D011651:Pulmonary Artery / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D050796:STAT3 Transcription Factor; C494088:Stat3 protein, rat