title: Secreted APE1/Ref-1 inhibits TNF-α-stimulated endothelial inflammation via thiol-disulfide exchange in TNF receptor.
abstract: Apurinic apyrimidinic endonuclease 1/Redox factor-1 (APE1/Ref-1) is a multifunctional protein with redox activity and is proved to be secreted from stimulated cells. The aim of this study was to evaluate the functions of extracellular APE1/Ref-1 with respect to leading anti-inflammatory signaling in TNF-α-stimulated endothelial cells in response to acetylation. Treatment of TNF-α-stimulated endothelial cells with an inhibitor of deacetylase that causes intracellular acetylation, considerably suppressed vascular cell adhesion molecule-1 (VCAM-1). During TSA-mediated acetylation in culture, a time-dependent increase in secreted APE1/Ref-1 was confirmed. The acetyl moiety of acetylated-APE1/Ref-1 was rapidly removed based on the removal kinetics. Additionally, recombinant human (rh) APE1/Ref-1 with reducing activity induced a conformational change in rh TNF-α receptor 1 (TNFR1) by thiol-disulfide exchange. Following treatment with the neutralizing anti-APE1/Ref-1 antibody, inflammatory signals via the binding of TNF-α to TNFR1 were remarkably recovered, leading to up-regulation of reactive oxygen species generation and VCAM-1, in accordance with the activation of p66(shc) and p38 MAPK. These results strongly indicate that anti-inflammatory effects in TNF-α-stimulated endothelial cells by acetylation are tightly linked to secreted APE1/Ref-1, which inhibits TNF-α binding to TNFR1 by reductive conformational change, with suggestion as an endogenous inhibitor of vascular inflammation.
authors.affiliation: Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon, 301-747, Republic of KOREA.
authors.forename: Myoung Soo
authors.initials: MS
authors.lastname: Park
authors.affiliation: Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon, 301-747, Republic of KOREA.
authors.forename: Sunga
authors.initials: S
authors.lastname: Choi
authors.affiliation: Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon, 301-747, Republic of KOREA.
authors.forename: Yu Ran
authors.initials: YR
authors.lastname: Lee
authors.affiliation: Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon, 301-747, Republic of KOREA.
authors.forename: Hee Kyoung
authors.initials: HK
authors.lastname: Joo
authors.affiliation: Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon, 301-747, Republic of KOREA.
authors.forename: Gun
authors.initials: G
authors.lastname: Kang
authors.affiliation: Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon, 301-747, Republic of KOREA.
authors.forename: Cuk-Seong
authors.initials: CS
authors.lastname: Kim
authors.affiliation: Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon, 301-747, Republic of KOREA.
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon, 301-747, Republic of KOREA.
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Lee
authors.affiliation: Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon, 301-747, Republic of KOREA.
authors.forename: Byeong Hwa
authors.initials: BH
authors.lastname: Jeon
mesh_terms: D000107:Acetylation; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D003593:Cytoplasm / Q000187:drug effects / Q000235:genetics; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects; D056572:Histone Deacetylase Inhibitors / Q000008:administration & dosage; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D010084:Oxidation-Reduction; D011485:Protein Binding; D011487:Protein Conformation / Q000187:drug effects; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage / Q000378:metabolism*; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics
chemical_list: D000893:Anti-Inflammatory Agents; C468769:GATAD2A protein, human; D056572:Histone Deacetylase Inhibitors; D047888:Receptors, Tumor Necrosis Factor, Type I; D012097:Repressor Proteins; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D048051:p38 Mitogen-Activated Protein Kinases; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase