title: Cocaine-mediated apoptosis in bovine coronary artery endothelial cells: role of nitric oxide.
abstract: The present study examined the role of nitric oxide in cocaine-induced apoptosis in bovine coronary artery endothelial cells (BCAECs). Cocaine produced a time-dependent decrease in cell viability and an increase in apoptosis in BCAECs, which were blocked by the nitric oxide donors DETA-NONOate (DETA-NO) and S-nitroso-N-acetyl-penicillamine. In accordance, cocaine decreased nitric oxide production in BCAECs at each time point of the study. Cocaine significantly increased caspase-3 activity that was blocked by the inhibitors of cytochrome c release (cyclosporin A), caspase-3 (Ac-DEVD-CHO), and caspase-9 (Z-LEHD-FMK), respectively. In addition, cocaine activated caspase-9, which was blocked by cyclosporin A and Z-LEHD-FMK. Ac-DEVD-CHO only partially blocked cocaine-induced caspase-9 activity. DETA-NO (20 microM) blocked cocaine-mediated activation of both caspase-9 and caspase-3. Cocaine decreased Bcl-2 protein levels, which was partially blocked by Ac-DEVD-CHO and Z-LEHD-FMK, but not by DETA-NO. Furthermore, cocaine induced a translocation of Bax from the cytosol to the mitochondria in BCAECs, and increased Bax levels in mitochondria by 2.2-fold. In accordance, cytosolic Bax levels decreased about 42%. Neither Ac-DEVD-CHO nor DETA-NO affected cocaine-induced translocation of Bax. We conclude that cocaine-induced Bcl-2 protein down-regulation and Bax translocation to the mitochondria are upstream signals of caspase-9 activation that precedes caspase-3. Cocaine-induced attenuation of nitric oxide plays a key role in the activation of the caspase cascade in BCAECs.
authors.affiliation: Center for Perinatal Biology, Department of Pharmacology, Loma Linda University School of Medicine, Loma Linda, California 92350, USA.
authors.forename: J
authors.initials: J
authors.lastname: He
authors.forename: Y
authors.initials: Y
authors.lastname: Xiao
authors.forename: L
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases / Q000187:drug effects* / Q000378:metabolism; D002417:Cattle; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D003042:Cocaine / Q000494:pharmacology*; D003331:Coronary Vessels / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009603:Nitroso Compounds / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D009603:Nitroso Compounds; D014662:Vasoconstrictor Agents; C094210:2,2'-(hydroxynitrosohydrazono)bis-ethanamine; D009569:Nitric Oxide; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases; D003042:Cocaine; D019331:NG-Nitroarginine Methyl Ester