title: [Expressions of HIF-α and its target gene in monochorionic twin placentas with twin-twin transfusion syndrome].
abstract: OBJECTIVE
  To determine hypoxia-inducible factor 1α (HIF-1α) and its target gene, vascular  endothelial growth factor (VEGF) and receptor (VEGFR-1) concentrations in the placentas of the donor and  recipient in monochorionic twin pregnancies with twin-twin transfusion syndrome (TTTS).
  
  
  METHODS
  Twenty  monochorionic twin pregnancy cases were included in the study (10 with and 10 without TTTS). Tissue protein  expressions of HIF-1α,VEGF and VEGFR-1 were determined by using immunohistochemistry. Western blot analysis  were used to quantify and compare the protein expression. RT-PCR were used to compare their mRNA expressions.
  
  
  RESULTS
  HIF-1α was mainly observed in trophoblastic cells and villi capillaries endothelial cells, and VEGF in  trophoblastic cells, endothelial cells and villi stromal cells; VEGFR-1 was mainly observed in villi  trophoblastic cells and vascular endothelial cells. The placenta protein and mRNA expression of HIF-1α and its  target gene in the donor placenta increased significantly (P<0.001) compared with that in the control placenta,  but the expression of HIF-1α and its target gene in the recipients tended to be similar in the controls  (P>0.05). There was no difference between the controls.
  
  
  CONCLUSIONS
  When the monochorionic twin placenta is  formed in the early period, HIF-1α, VEGF and VEGFR-1 are over-expressed, which may affect the placenta  angiogenesis and induce TTTS .
authors.affiliation: Department of Gynaecology and Obstetrics, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Ling-ling
authors.initials: LL
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Shao
authors.forename: Peng-bo
authors.initials: PB
authors.lastname: Yuan
authors.forename: Xiao-yue
authors.initials: XY
authors.lastname: Guo
authors.forename: Xiao-wei
authors.initials: XW
authors.lastname: Zhang
authors.forename: Yang-yu
authors.initials: YY
authors.lastname: Zhao
mesh_terms: D005260:Female; D005330:Fetofetal Transfusion / Q000378:metabolism* / Q000503:physiopathology; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D007231:Infant, Newborn; D010920:Placenta / Q000098:blood supply / Q000378:metabolism*; D011247:Pregnancy; D014430:Twins, Monozygotic; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000235:genetics / Q000378:metabolism*
chemical_list: C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1