title: [Changes of ubiquitin-proteasome system in human umbilical vein endothelial cells induced by oxidative low density lipoprotein].
abstract: OBJECTIVE
  To explore the role of ubiquitin-proteasome system (UPS) in the injury of human umbilical vein endothelial cells (HUVECs) induced by oxidative low density lipoprotein (ox-LDL).
  
  
  METHODS
  After exposure to ox-LDL, the levels of ubiquitin (Ub), E1 (ubiquitin activation enzyme), E2 (ubiquitin conjugating enzymes) and E3 (ubiquitin protein ligating enzymes) were detected by Western blot.
  
  
  RESULTS
  The levels of Ub, E1, E2 and E3 were up-regulated after induced by ox-LDL (grey level: 0.46 ± 0.08 vs 0.25 ± 0.09; 0.63 ± 0.09 vs 0.45 ± 0.09; 0.49 ± 0.07 vs 0.35 ± 0.06; 0.67 ± 0.05 vs 0.45 ± 0.05; ox-LDL 100 µg/ml, P < 0.05). The regulations peaked at 12 h and 24 h (12 h grey level: 0.58 ± 0.08 vs 0.25 ± 0.09; 0.72 ± 0.08 vs 0.45 ± 0.08; 0.65 ± 0.10 vs 0.35 ± 0.06; 0.65 ± 0.05 vs 0.43 ± 0.05, P < 0.05; 24h grey level: 0.72 ± 0.08 vs 0.25 ± 0.09; 0.79 ± 0.08 vs 0.45 ± 0.08; 0.72 ± 0.04 vs 0.35 ± 0.06; 0.65 ± 0.05 vs 0.43 ± 0.05, P < 0.05).
  
  
  CONCLUSIONS
  The treatment of ox-LDL may activate the UPS to promote the degradation of HUVECs.
authors.affiliation: First Affiliated Hospital, Soochow University, Suzhou 215000, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Zhou
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Email: liucf@suda.edu.cn.
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Liu
mesh_terms: D003593:Cytoplasm; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008077:Lipoproteins, LDL; D046988:Proteasome Endopeptidase Complex; D025801:Ubiquitin; D015854:Up-Regulation
chemical_list: D008077:Lipoproteins, LDL; D025801:Ubiquitin; D046988:Proteasome Endopeptidase Complex