title: Cellular targets of the myeloperoxidase-derived oxidant hypothiocyanous acid (HOSCN) and its role in the inhibition of glycolysis in macrophages.
abstract: Myeloperoxidase (MPO) released at sites of inflammation catalyzes the formation of the oxidants hypochlorous acid (HOCl) and hypothiocyanous acid (HOSCN) from H2O2 and halide and pseudo-halide ions. HOCl, a major oxidant produced under physiological conditions reacts rapidly with many biological molecules, and is strongly linked with tissue damage during inflammatory disease. The role of HOSCN in disease is less clear, though it can initiate cellular damage by pathways involving the selective oxidation of thiol-containing proteins. Utilizing a thiol-specific proteomic approach, we explored the cellular targets of HOSCN in macrophages (J774A.1). We report that multiple thiol-containing proteins involved in metabolism and glycolysis; fructose bisphosphate aldolase, triosephosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and creatine kinase, together with a number of chaperone, antioxidant and structural proteins, were modified in a reversible manner in macrophages treated with HOSCN. The modification of the metabolic enzymes was associated with a decrease in basal glycolysis, glycolytic reserve, glycolytic capacity and lactate release, which was only partly reversible on further incubation in the absence of HOSCN. Inhibition of glycolysis preceded cell death and was seen in cells exposed to low concentrations (≤25µM) of HOSCN. The ability of HOSCN to inhibit glycolysis and perturb energy production is likely to contribute to the cell death seen in macrophages on further incubation after the initial treatment period, which may be relevant for the propagation of inflammatory disease in smokers, who have elevated plasma levels of the HOSCN precursor, thiocyanate.
authors.affiliation: The Heart Research Institute, 7 Eliza St., Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Dominic T
authors.initials: DT
authors.lastname: Love
authors.affiliation: The Heart Research Institute, 7 Eliza St., Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Tessa J
authors.initials: TJ
authors.lastname: Barrett
authors.affiliation: School of Molecular Bioscience, School of Medical Sciences, and Charles Perkins Centre, University of Sydney, 2006, Australia.
authors.forename: Melanie Y
authors.initials: MY
authors.lastname: White
authors.affiliation: School of Molecular Bioscience, School of Medical Sciences, and Charles Perkins Centre, University of Sydney, 2006, Australia.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Cordwell
authors.affiliation: The Heart Research Institute, 7 Eliza St., Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia; Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Blegdamsvej 3, Copenhagen 2200, Denmark.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Davies
authors.affiliation: The Heart Research Institute, 7 Eliza St., Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Sydney, NSW 2006, Australia. Electronic address: clare.hawkins@hri.org.au.
authors.forename: Clare L
authors.initials: CL
authors.lastname: Hawkins
mesh_terms: D050197:Atherosclerosis / Q000378:metabolism* / Q000473:pathology; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D005978:Glutathione / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007249:Inflammation / Q000378:metabolism* / Q000473:pathology; D008264:Macrophages / Q000378:metabolism; D016877:Oxidants; D009195:Peroxidase / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000235:genetics; D040901:Proteomics; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013861:Thiocyanates / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D016877:Oxidants; D013438:Sulfhydryl Compounds; D013861:Thiocyanates; C517667:hypothiocyanous acid; D006861:Hydrogen Peroxide; D009195:Peroxidase; D005978:Glutathione
keywords: Atherosclerosis; Glycolysis; Hypothiocyanous acid; Inflammation; Myeloperoxidase; Protein oxidation; Thiol