title: Hypoxia-induced apoptosis in endothelial cells and embryonic stem cells.
abstract: BACKGROUND
  To evaluate the influence of hypoxia and molecular events in endothelial and embryonic stem cells.
  
  
  METHODS
  Human umbilical vein endothelial cells (HUVECs) and mouse embryoid body (EB) cells were subjected to hypoxic conditions for different time courses. DNA fragmentation assay, quantification of apoptotic cells by TUNEL assay measured by flowcytometry, and Western blot analysis for the molecular events of apoptosis were performed.
  
  
  RESULTS
  DNA fragmentation could be identified under hypoxic conditions in HUVECs and mouse EBs. The DNA fragmentation increased when the hypoxic interval was extended. In situ internucleosomal DNA fragmentation-TUNEL assay also found that the percentages of apoptotic cells increased gradually in HUVECs and mouse EBs when the hypoxic interval was extended. Furthermore, the levels of expression of p53 and Bax both increased in hypoxic conditions.
  
  
  CONCLUSIONS
  Hypoxia increases both HUVEC and mouse EB apoptosis, which is associated with increase in p53/Bax expression.
authors.affiliation: Department of Obstetrics and Gynecology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: C -N
authors.initials: C-
authors.lastname: Lee
authors.forename: W -F
authors.initials: W-
authors.lastname: Cheng
authors.forename: M -C
authors.initials: M-
authors.lastname: Chang
authors.forename: Y -N
authors.initials: Y-
authors.lastname: Su
authors.forename: C -A
authors.initials: C-
authors.lastname: Chen
authors.forename: F -J
authors.initials: F-
authors.lastname: Hsieh
mesh_terms: D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D015687:Cell Hypoxia; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D053938:DNA Fragmentation; D053595:Embryonic Stem Cells / Q000166:cytology*; D042783:Endothelial Cells / Q000166:cytology*; D005434:Flow Cytometry; D006801:Humans; D020287:In Situ Nick-End Labeling; D051379:Mice; D013997:Time Factors; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D004247:DNA