title: Hydrogen peroxide-mediated necrosis induction in HUVECs is associated with an atypical pattern of caspase-3 cleavage.
abstract: Oxidative stress, continuously exerted during chronic inflammation, has been implicated as a major causative agent of cellular dysfunction and cell death. In the present study, we investigated the impact of oxidative stress on the mode of cell death in HUVECs using H2O2 as a model reagent. We found that the predominant form of cell death was necrosis. Necrosis induction was accompanied by a distinct mode of caspase-3 cleavage, yielding a 29-kDa fragment. While inhibition of caspases could not prevent the generation of the 29-kDa fragment, general protease inhibitors, such as leupeptin and LLNL, proved to be effective in inhibiting the distinct processing pattern of caspase-3. These results suggest that caspases can act as substrates for non-caspase proteases in cells primed for necrosis induction. Thus, the pattern of caspase-3 cleavage might reflect the proteolytic system engaged in the cell death machinery in HUVECs.
authors.affiliation: Vascular Biology Group, Division of Experimental Pathophysiology and Immunology, Innsbruck Biocenter, Innsbruck Medical University, Fritz-Pregl-Str.3, 6020 Innsbruck, Austria.
authors.forename: Adam
authors.initials: A
authors.lastname: Csordas
authors.forename: Georg
authors.initials: G
authors.lastname: Wick
authors.forename: David
authors.initials: D
authors.lastname: Bernhard
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000378:metabolism; D001549:Benzamides / Q000378:metabolism; D053148:Caspase 3; D053179:Caspase 7; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D002460:Cell Line; D024161:Collagen Type XI / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008564:Membrane Potentials; D008928:Mitochondria / Q000378:metabolism; D009336:Necrosis; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D013997:Time Factors; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D001549:Benzamides; C499319:COL11A2 protein, human; D061945:Caspase Inhibitors; D024161:Collagen Type XI; D004791:Enzyme Inhibitors; D016877:Oxidants; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C025160:3-aminobenzamide; D045304:Cytochromes c; D006861:Hydrogen Peroxide; C505407:CASP3 protein, human; C505520:CASP7 protein, human; D053148:Caspase 3; D053179:Caspase 7; D020169:Caspases