title: Carbon monoxide-releasing molecule CORM-3 suppresses vascular endothelial cell SOD-1/SOD-2 activity while up-regulating the cell surface levels of SOD-3 in a heparin-dependent manner.
abstract: The role of CO in the modulation of antioxidant enzyme function has not been investigated, yet. In this study we assessed the effects and potential mechanisms of the ruthenium-based water-soluble CO-releasing molecule CORM-3 in the modulation of superoxide dismutase (SOD) activity/binding in vascular endothelial cells (HUVECs). To this end, HUVECs were treated with CORM-3 (100 μM) and assessed for total SOD activity in cell lysates (cell-associated SOD activity) and cell culture supernatants (soluble SOD). In parallel, release/binding of extracellular SOD (SOD-3) in the absence or presence of heparin (1-10 IU/ml), a key factor regulating SOD-3 cell-surface binding, was investigated. In addition, the effects of CORM-3 on the modulation of purified SOD-1 and SOD-2 activity in a cell-free system were also assessed. The results obtained indicate that CORM-3 effectively suppresses the activity of both purified SOD-1 and SOD-2. These findings were accompanied by CORM-3-dependent attenuation of total cell-associated SOD activity (without affecting SOD-1/SOD-2 protein expression) and a subsequent increase in ROS production (DHR123 oxidation) in HUVECs. In parallel, a concomitant increase in soluble-SOD activity (due to increased SOD-3 release from the cell surface) was observed in the cell culture supernatants. However, in the presence of heparin, total cell-associated SOD activity was significantly increased by CORM-3, because of increased binding of SOD-3 to HUVECs. Taken together these findings indicate for the first time that CORM-3 modulates both the activity of intracellular SOD (i.e., SOD-1 and SOD-2) and the binding of extracellular SOD (SOD-3) to the cell surface.
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, London, ON, Canada N6A 4G4.
authors.forename: Shinjiro
authors.initials: S
authors.lastname: Mizuguchi
authors.forename: Alfredo
authors.initials: A
authors.lastname: Capretta
authors.forename: Shigefumi
authors.initials: S
authors.lastname: Suehiro
authors.forename: Noritoshi
authors.initials: N
authors.lastname: Nishiyama
authors.forename: Patrick
authors.initials: P
authors.lastname: Luke
authors.forename: Richard F
authors.initials: RF
authors.lastname: Potter
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Fraser
authors.forename: Gediminas
authors.initials: G
authors.lastname: Cepinskas
mesh_terms: D002248:Carbon Monoxide / Q000494:pharmacology*; D002474:Cell-Free System / Q000378:metabolism; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects* / Q000201:enzymology; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D009942:Organometallic Compounds / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D015854:Up-Regulation; D000099156:Superoxide Dismutase 2
chemical_list: D002248:Carbon Monoxide; D006493:Heparin; D009942:Organometallic Compounds; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D000099156:Superoxide Dismutase 2; C000606290:SOD1 protein, human; C476530:tricarbonylchloro(glycinato)ruthenium(II)