title: OxLDL triggers retrograde translocation of arginase2 in aortic endothelial cells via ROCK and mitochondrial processing peptidase.
abstract: BACKGROUND
  Increased arginase activity contributes to endothelial dysfunction by competition for l-arginine substrate and reciprocal regulation of nitric oxide synthase (NOS). The rapid increase in arginase activity in human aortic endothelial cells exposed to oxidized low-density lipoprotein (OxLDL) is consistent with post-translational modification or subcellular trafficking.
  
  
  OBJECTIVE
  To test the hypotheses that OxLDL triggers reverse translocation of mitochondrial arginase 2 (Arg2) to cytosol and Arg2 activation, and that this process is dependent on mitochondrial processing peptidase, lectin-like OxLDL receptor-1 receptor, and rho kinase.
  
  
  RESULTS
  OxLDL-triggered translocation of Arg2 from mitochondria to cytosol in human aortic endothelial cells and in murine aortic intima with a concomitant rise in arginase activity. All of these changes were abolished by inhibition of mitochondrial processing peptidase or by its siRNA-mediated knockdown. Rho kinase inhibition and the absence of the lectin-like OxLDL receptor-1 in knockout mice also ablated translocation. Aminoterminal sequencing of Arg2 revealed 2 candidate mitochondrial targeting sequences, and deletion of either of these confined Arg2 to the cytoplasm. Inhibitors of mitochondrial processing peptidase or lectin-like OxLDL receptor-1 knockout attenuated OxLDL-mediated decrements in endothelial-specific NO production and increases in superoxide generation. Finally, Arg2(-/-) mice bred on an ApoE(-/-) background showed reduced plaque load, reduced reactive oxygen species production, enhanced NO, and improved endothelial function when compared with ApoE(-/-) controls.
  
  
  CONCLUSIONS
  These data demonstrate dual distribution of Arg2, a protein with an unambiguous mitochondrial targeting sequence, in mammalian cells, and its reverse translocation to cytoplasm by alterations in the extracellular milieu. This novel molecular mechanism drives OxLDL-mediated arginase activation, endothelial NOS uncoupling, endothelial dysfunction, and atherogenesis.
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Deepesh
authors.initials: D
authors.lastname: Pandey
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Anil
authors.initials: A
authors.lastname: Bhunia
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Oh
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Fumin
authors.initials: F
authors.lastname: Chang
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Yehudit
authors.initials: Y
authors.lastname: Bergman
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Jae Hyung
authors.initials: JH
authors.lastname: Kim
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Janna
authors.initials: J
authors.lastname: Serbo
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Tatiana N
authors.initials: TN
authors.lastname: Boronina
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Robert N
authors.initials: RN
authors.lastname: Cole
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Jennifer
authors.initials: J
authors.lastname: Van Eyk
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Alan T
authors.initials: AT
authors.lastname: Remaley
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
authors.forename: Dan E
authors.initials: DE
authors.lastname: Berkowitz
authors.affiliation: From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.). LRomer@jhmi.edu.
authors.forename: Lewis H
authors.initials: LH
authors.lastname: Romer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D001018:Aortic Diseases / Q000201:enzymology / Q000235:genetics / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control; D001057:Apolipoproteins E / Q000172:deficiency / Q000235:genetics; D001119:Arginase / Q000235:genetics / Q000378:metabolism*; D050197:Atherosclerosis / Q000201:enzymology / Q000235:genetics / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control; D002478:Cells, Cultured; D003600:Cytosol / Q000201:enzymology; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology*; D004789:Enzyme Activation; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology*; D008969:Molecular Sequence Data; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport; D034622:RNA Interference; D051127:Scavenger Receptors, Class E / Q000172:deficiency / Q000235:genetics; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000096122:Mitochondrial Processing Peptidase
chemical_list: D001057:Apolipoproteins E; D001119:Arginase; D008077:Lipoproteins, LDL; D008666:Metalloendopeptidases; D047428:Protein Kinase Inhibitors; D051127:Scavenger Receptors, Class E; D054460:rho-Associated Kinases; D000096122:Mitochondrial Processing Peptidase; C495138:Olr1 protein, mouse; C099252:oxidized low density lipoprotein; C477631:ARG2 protein, human; C481673:Arg2 protein, mouse
keywords: arginase; atherosclerosis; mitochondria; mitochondrial processing peptidase; nitric oxide synthase type III; oxidized low density lipoprotein