title: [Alterations in reactive oxygen species and dimethylarginine dimethylaminohydrolase-asymmetric dimethyl-arginine system in the process of endothelial cell senescence induced by high glucose].
abstract: OBJECTIVE
  To investigate the changes in reactive oxygen species (ROS) and dimethyl- arginine dimethylaminohydrolase-asymmetric dimethylarginine (DDAH-ADMA) system in the process of endothelial cell senescence after exposure to high glucose.
  
  
  METHODS
  The human umbilical vein endothelial cells (HUVECs) were cultured with different concentrations of glucose, e.g. 5.5 mmol/L (normal level), and high levels as 11.0, 22.0 and 33.0 mmol/L, for 48 hours, respectively. Subsequently, SA-β-gal staining was used to evaluate senescence of cells. Telomerase activity was detected by polymerase chain reaction-enzyme linked immunosorbent assay (PCR-ELISA). The intracellular ROS level was measured by flow cytometry. The ADMA concentration and DDAH activity were determined with high-performance liquid chromatography.
  
  
  RESULTS
  Compared with normal glucose concentration group, after the endothelial cells were treated with high glucose concentration (11.0-33.0 mmol/L) for 48 hours, the number of SA-β-gal positive cells was increased significantly [(7.00±1.73)%, (12.67±2.03)%, (16.00±2.26)% vs. (4.00±1.33)%, P>0.05, P<0.05, P<0.05] and the telomerase activity was inhibited dramatically [(91.32±4.01)%, (78.44±3.78)%, (56.04±3.35)% vs. 100%, all P<0.05]. The ROS level (mfi) was increased in all high glucose groups (159.84±27.52, 188.99±18.77, 244.56±20.96 vs.117.11±18.76, P<0.05 or P<0.01). At the same time, the ADMA (μmol/L) production was increas ed (0.78±0.14, 0.88±0.18, 1.08±0.15 vs. 0.70±0.12, P>0.05, P<0.05, P<0.05), and DDAH activity was decreased [(91.32±4.01)%, (78.44±3.78)%, (56.04±3.35)% vs.100%, all P<0.05].
  
  
  CONCLUSIONS
  High glucose can accelerate endothelial cells senescence in dose-dependent manner and the underlying mechanism may be related to an increased oxidative stress and change in DDAH-ADMA system.
authors.affiliation: Department of Endocrinology and Metabolism, the Affiliated Hospital of Liaoning University of Traditional Chinese Medicine, Shenyang 110031, Liaoning, China.
authors.forename: Tong-ning
authors.initials: TN
authors.lastname: Yi
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.forename: Shi-jia
authors.initials: SJ
authors.lastname: Yu
authors.forename: Tian-shu
authors.initials: TS
authors.lastname: Gao
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism*; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects*; D005947:Glucose / Q000009:adverse effects*; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism*; D006801:Humans; D019001:Nitric Oxide Synthase / Q000378:metabolism; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; C018524:N,N-dimethylarginine; D001120:Arginine; D019001:Nitric Oxide Synthase; D000581:Amidohydrolases; C059999:dimethylargininase; D005947:Glucose