title: The glutathione mimic ebselen inhibits oxidative stress but not endoplasmic reticulum stress in endothelial cells.
abstract: OBJECTIVE
  Reactive oxygen species are associated with cardiovascular disease, diabetes, and atherosclerosis, yet the use of antioxidants in clinical trials has been ineffective at improving outcomes. In endothelial cells, high-dextrose-induced oxidative stress and endoplasmic reticulum stress promote endothelial dysfunction leading to the recruitment and activation of peripheral blood lymphocytes and the breakdown of barrier function. Ebselen, a glutathione peroxidase 1 (GPX1) mimic, has been shown to improve β-cell function in diabetes and prevent atherosclerosis.
  
  
  METHODS
  To determine if ebselen inhibits both oxidative stress and endoplasmic reticulum (ER) stress in endothelial cells, we examined its effects in human umbilical vein endothelial cells (HUVEC) and human coronary artery endothelial cells (HCAEC) with and without high-dextrose. Oxidative stress and ER stress were measured by 2-methyl-6-(4-methoxyphenyl)-3,7-dihydroimidazo[1,2-A]pyrazin-3-one hydrochloride chemiluminescence and ER stress alkaline phosphatase assays, respectively. GPX1 over-expression and knockdown were performed by transfecting cells with a GPX1 expression construct or a GPX1-specific siRNA, respectively.
  
  
  RESULTS
  Ebselen inhibited dextrose-induced oxidative stress but not ER stress in both HUVEC and HCAEC. Ebselen also had no effect on tunicamycin-induced ER stress in HCAEC. Furthermore, augmentation of GPX1 activity directly by sodium selenite supplementation or transfection of a GPX1 expression plasmid decreased dextrose-induced oxidative stress but not ER stress, while GPX1 knockout enhanced oxidative stress but had no effect on ER stress.
  
  
  CONCLUSIONS
  These results suggest that ebselen targets only oxidative stress but not ER stress.
authors.affiliation: Department of Medicine, University of Florida College of Medicine, Jacksonville, FL, USA.
authors.forename: Salma Makhoul
authors.initials: SM
authors.lastname: Ahwach
authors.affiliation: Department of Medicine, University of Florida College of Medicine, Jacksonville, FL, USA.
authors.forename: Melanie
authors.initials: M
authors.lastname: Thomas
authors.affiliation: Department of Medicine, University of Florida College of Medicine, Jacksonville, FL, USA.
authors.forename: Luisa
authors.initials: L
authors.lastname: Onstead-Haas
authors.affiliation: Department of Medicine, University of Florida College of Medicine, Jacksonville, FL, USA.
authors.forename: Arshag D
authors.initials: AD
authors.lastname: Mooradian
authors.affiliation: Department of Medicine, University of Florida College of Medicine, Jacksonville, FL, USA. Electronic address: michael.haas@jax.ufl.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Haas
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001393:Azoles / Q000494:pharmacology*; D040761:Biomimetic Materials / Q000494:pharmacology*; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D005978:Glutathione; D005979:Glutathione Peroxidase / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism*; D006801:Humans; D054833:Isoindoles; D016566:Organoselenium Compounds / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D018038:Sodium Selenite / Q000494:pharmacology; D014131:Trace Elements / Q000494:pharmacology; D000094765:Glutathione Peroxidase GPX1
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001393:Azoles; D054833:Isoindoles; D016566:Organoselenium Compounds; D014131:Trace Elements; C042986:ebselen; D005979:Glutathione Peroxidase; D005978:Glutathione; D018038:Sodium Selenite; D000094765:Glutathione Peroxidase GPX1; C000722067:GPX1 protein, human
keywords: Cardiovascular disease; Dextrose; Ebselen; Endoplasmic reticulum stress; Endothelial cells