title: Bromfenvinphos induced suicidal death of human erythrocytes.
abstract: The organophosphorus pesticide bromfenvinphos ((E,Z)-O,O-diethyl-O-[1-(2,4-dichlorophenyl)-2-bromovinyl] phosphate) has been shown to decrease hematocrit and hemoglobin levels in blood presumably by triggering oxidative stress of erythrocytes. Oxidative stress is known to activate erythrocytic Ca(2+) permeable unselective cation channels leading to Ca(2+) entry and increase of cytosolic Ca(2+) activity ([Ca(2+)]i), which in turn triggers eryptosis, the suicidal death characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. The present study explored, whether and how bromfenvinphos induces eryptosis. To this end, phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, hemolysis from hemoglobin release, [Ca(2+)]i from Fluo3-fluorescence, and ROS formation from DCFDA dependent fluorescence. As a result, a 48hour exposure of human erythrocytes to bromfenvinphos (≥100μM) significantly increased the percentage of annexin-V-binding cells, significantly decreased forward scatter, significantly increased Fluo3-fluorescence, and significantly increased DCFDA fluorescence. The effect of bromfenvinphos on annexin-V-binding and forward scatter was significantly blunted, but not abolished by removal of extracellular Ca(2+). In conclusion, bromfenvinphos triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect in part due to stimulation of ROS formation and Ca(2+) entry.
authors.affiliation: Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076 Tuebingen, Germany; Department of Biochemistry, Biophysics and General Pathology, School of Medicine and Surgery, Second University of Naples, Via L. De Crecchio 7, 80138 Naples, Italy.
authors.forename: Arbace
authors.initials: A
authors.lastname: Officioso
authors.affiliation: Department of Biochemistry, Biophysics and General Pathology, School of Medicine and Surgery, Second University of Naples, Via L. De Crecchio 7, 80138 Naples, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Manna
authors.affiliation: Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076 Tuebingen, Germany.
authors.forename: Kousi
authors.initials: K
authors.lastname: Alzoubi
authors.affiliation: Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076 Tuebingen, Germany. Electronic address: florian.lang@uni-tuebingen.de.
authors.forename: Florian
authors.initials: F
authors.lastname: Lang
mesh_terms: D002118:Calcium / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002709:Chlorfenvinphos / Q000031:analogs & derivatives* / Q000633:toxicity; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D007306:Insecticides / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D007306:Insecticides; D017382:Reactive Oxygen Species; C014369:bromfenvinphos; D002709:Chlorfenvinphos; D002118:Calcium
keywords: Calcium; Cell volume; Eryptosis; Oxidative stress; Phosphatidylserine