title: Zopolrestat Induced Suicidal Death of Human Erythrocytes.
abstract: OBJECTIVE
  The aldose reductase inhibitor zopolrestat has been shown to either decrease or increase apoptosis, the suicidal death of nucleated cells. Erythrocytes may similarly enter suicidal death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include oxidative stress, Ca2+ entry with increase of cytosolic Ca2+ activity ([Ca2+]i), and ceramide formation. The present study explored, whether and how zopolrestat induces eryptosis.
  
  
  METHODS
  Phosphatidylserine exposure at the cell surface was estimated from annexin V binding, cell volume from forward scatter, oxidative stress from DCFDA dependent fluorescence, [Ca2+]i from Fluo3-fluorescence, and ceramide abundance utilizing specific antibodies.
  
  
  RESULTS
  A 48 hours exposure of human erythrocytes to zopolrestat (≥ 150 µg/ml) significantly increased the percentage of annexin-V-binding cells, significantly decreased forward scatter (≥ 125 µg/ml), significantly increased Fluo3-fluorescence (200 µg/ml), significantly increased ceramide abundance (150 µg/ml), but did not significantly modify DCFDA fluorescence. The effect of zopolrestat on annexin-V-binding was significantly blunted, but not abolished by removal of extracellular Ca2+.
  
  
  CONCLUSIONS
  Exposure of human erythrocytes to zopolrestat triggers cell shrinkage and cell membrane scrambling, an effect in part due to Ca2+ entry and ceramide.
authors.forename: Ghada
authors.initials: G
authors.lastname: Bouguerra
authors.forename: Rosi
authors.initials: R
authors.lastname: Bissinger
authors.forename: Salem
authors.initials: S
authors.lastname: Abbès
authors.forename: Florian
authors.initials: F
authors.lastname: Lang
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D017209:Apoptosis / Q000187:drug effects*; D052160:Benzothiazoles / Q000633:toxicity*; D002118:Calcium / Q000378:metabolism; D048429:Cell Size / Q000187:drug effects; D002518:Ceramides / Q000032:analysis; D004791:Enzyme Inhibitors / Q000633:toxicity*; D004797:Enzyme-Linked Immunosorbent Assay; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D010793:Phthalazines / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014966:Xanthenes / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D052160:Benzothiazoles; D002518:Ceramides; D004791:Enzyme Inhibitors; D010793:Phthalazines; D017382:Reactive Oxygen Species; D014966:Xanthenes; C067172:zopolrestat; C059715:Fluo-3; D002118:Calcium