title: Telomerase activity and telomere length distribution in vascular endothelial cells in a short-term culture under the presence of hydrogen peroxide.
abstract: OBJECTIVE
  The aim of this study was to assess the biological effects of oxidative stress on human vascular endothelial cells.
  
  
  METHODS
  The telomeric changes and the alterations of the expression of telomere-associated proteins in human umbilical venous endothelial cells (HUVEC) cultured in the presence of hydrogen peroxide (H2 O2 ) were analyzed.
  
  
  RESULTS
  During the culture, the cell growth rate decreased, whereas the telomerase activity of the surviving cells increased. As the H2 O2 level increased, long telomeres decreased proportionally, thus resulting in a telomere length distribution that was rich in short telomeres. These observations suggested that H2 O2 -affected endothelial cells bear telomeric features similar to those of aged cells. In contrast, the expression of telomere-associated proteins, TRF1 and TRF2, showed different changes. TRF1 increased in relation to H2 O2 concentration, whereas TRF2 showed no significant change. The surviving cells exposed to H2 O2 showed a H2 O2 -dose dependent increase in telomerase activity, whereas the telomere protein and RNA components were only elevated in low concentrations of H2 O2 .
  
  
  CONCLUSIONS
  The increase in telomerase activity and TRF1 protein expression of vascular endothelial cell might show an aspect of cellular protective reaction against oxygen stress.
authors.affiliation: Department of Cardiovascular, Respiratory, and Geriatric Medicine, Kyushu University Beppu Hospital, Beppu, Oita, Japan. maedat@beppu.kyushu-u.ac.jp
authors.forename: Toyoki
authors.initials: T
authors.lastname: Maeda
authors.forename: Jing-Zhi
authors.initials: JZ
authors.lastname: Guan
authors.forename: Masamichi
authors.initials: M
authors.lastname: Koyanagi
authors.forename: Naoki
authors.initials: N
authors.lastname: Makino
mesh_terms: D015153:Blotting, Western; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D018384:Oxidative Stress; D012313:RNA / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000096:biosynthesis / Q000235:genetics*; D016615:Telomere / Q000235:genetics* / Q000378:metabolism
chemical_list: D012313:RNA; D006861:Hydrogen Peroxide; D019098:Telomerase