title: CCL2 nitration is a negative regulator of chemokine-mediated inflammation.
abstract: Chemokines promote leukocyte recruitment during inflammation. The oxidative burst is an important effector mechanism, this leads to the generation of reactive nitrogen species (RNS), including peroxynitrite (ONOO). The current study was performed to determine the potential for nitration to alter the chemical and biological properties of the prototypical CC chemokine, CCL2. Immunofluorescence was performed to assess the presence of RNS in kidney biopsies. Co-localisation was observed between RNS-modified tyrosine residues and the chemokine CCL2 in diseased kidneys. Nitration reduced the potential of CCL2 to stimulate monocyte migration in diffusion gradient chemotaxis assays (p < 0.05). This was consistent with a trend towards reduced affinity of the nitrated chemokine for its cognate receptor CCR2b. The nitrated chemokine was unable to induce transendothelial monocyte migration in vitro and failed to promote leukocyte recruitment when added to murine air pouches (p < 0.05). This could potentially be attributed to reduced glycosaminoglycan binding ability, as surface plasmon resonance spectroscopy showed that nitration reduced heparan sulphate binding by CCL2. Importantly, intravenous administration of nitrated CCL2 also inhibited the normal recruitment of leukocytes to murine air pouches filled with unmodified CCL2. Together these data suggest that nitration of CCL2 during inflammation provides a mechanism to limit and resolve acute inflammation.
authors.affiliation: Applied Immunobiology and Transplantation Group, Institute of Cellular Medicine, Medical School, University of Newcastle Upon Tyne, NE2 4HH, UK.
authors.forename: Catriona E
authors.initials: CE
authors.lastname: Barker
authors.affiliation: Applied Immunobiology and Transplantation Group, Institute of Cellular Medicine, Medical School, University of Newcastle Upon Tyne, NE2 4HH, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Thompson
authors.affiliation: Faculty of Applied Science, University of Sunderland, Sunderland, SR1 3SD, UK.
authors.forename: Graeme
authors.initials: G
authors.lastname: O'Boyle
authors.affiliation: Institut de Biologie Structurale, UMR 5075, Univ. Grenoble Alpes, CNRS, CEA, F-38027, Grenoble, France.
authors.forename: Hugues
authors.initials: H
authors.lastname: Lortat-Jacob
authors.affiliation: Applied Immunobiology and Transplantation Group, Institute of Cellular Medicine, Medical School, University of Newcastle Upon Tyne, NE2 4HH, UK.
authors.forename: Neil S
authors.initials: NS
authors.lastname: Sheerin
authors.affiliation: Applied Immunobiology and Transplantation Group, Institute of Cellular Medicine, Medical School, University of Newcastle Upon Tyne, NE2 4HH, UK.
authors.forename: Simi
authors.initials: S
authors.lastname: Ali
authors.affiliation: Applied Immunobiology and Transplantation Group, Institute of Cellular Medicine, Medical School, University of Newcastle Upon Tyne, NE2 4HH, UK.
authors.forename: John A
authors.initials: JA
authors.lastname: Kirby
mesh_terms: D000818:Animals; D001665:Binding Sites; D002465:Cell Movement / Q000235:genetics; D018932:Chemokine CCL2 / Q000737:chemistry / Q000378:metabolism*; D018925:Chemokines / Q000378:metabolism; D007249:Inflammation / Q000378:metabolism* / Q000473:pathology; D007962:Leukocytes / Q000378:metabolism; D051379:Mice; D009000:Monocytes / Q000378:metabolism; D018384:Oxidative Stress / Q000235:genetics; D030421:Peroxynitrous Acid / Q000737:chemistry / Q000378:metabolism; D026361:Reactive Nitrogen Species / Q000737:chemistry / Q000378:metabolism*; D054390:Receptors, CCR2 / Q000235:genetics / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
chemical_list: D018932:Chemokine CCL2; D018925:Chemokines; D026361:Reactive Nitrogen Species; D054390:Receptors, CCR2; D030421:Peroxynitrous Acid; D014443:Tyrosine