title: Neutralization of osteopontin attenuates neutrophil migration in sepsis-induced acute lung injury.
abstract: BACKGROUND
  Sepsis refers to severe systemic inflammation leading to acute lung injury (ALI) and death. Introducing novel therapies can reduce the mortality in ALI. Osteopontin (OPN), a secretory glycoprotein produced by immune reactive cells, plays a deleterious role in various inflammatory diseases. However, its role in ALI caused by sepsis remains unexplored. We hypothesize that treatment with an OPN-neutralizing antibody (anti-OPN Ab) protects mice against ALI during sepsis.
  
  
  METHODS
  Sepsis was induced in 8-week-old male C57BL/6 mice by cecal ligation and puncture (CLP). Anti-OPN Ab or non-immunized IgG as control, at a dose of 50 μg/mouse, was intravenously injected at the time of CLP. After 20 hours, the expression of OPN and proinflammatory cytokines in tissues and plasma was examined by real-time PCR, Western blot, and ELISA. Plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) and the lung myeloperoxidase (MPO) levels were determined by colorimetric assays. Lung damage and neutrophil infiltrations were determined by histological H&E and Gr-1 staining, respectively. The effect of recombinant mouse OPN (rmOPN) on human neutrophil-like cell (HL-60) migration was performed by Boyden chamber assays and the involvement of intracellular signaling molecules in HL-60 cells was revealed by Western blot.
  
  
  RESULTS
  After 20 hours of sepsis, mRNA and protein levels of OPN were significantly induced in lungs, spleen, and plasma. Treatment with an anti-OPN Ab in septic mice significantly reduced the plasma levels of ALT, AST, and LDH, and the proinflammatory cytokines IL-6, IL-1β and the chemokine MIP-2, compared with the vehicle group. Similarly, the lung mRNA and protein expressions of proinflammatory cytokines and chemokine were greatly reduced in anti-OPN Ab-treated animals. The lung histological architecture, MPO and neutrophil infiltration were significantly improved in anti-OPN Ab-treated mice compared with the vehicle animals. Treatment of rmOPN in HL-60 cells significantly increased their migration, in vitro. The neutrophils treated with rmOPN remarkably increased the levels of phospho focal adhesion kinase (pFAK), phospho extracellular signal-regulated kinase (pERK) and phospho p38.
  
  
  CONCLUSIONS
  Our findings clearly demonstrate the beneficial outcomes of anti-OPN Ab treatment in protecting against ALI, implicating a novel therapeutic strategy in sepsis.
authors.affiliation: Department of Surgery, Hofstra North Shore-LIJ School of Medicine and Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA. Yhirano@nshs.edu.|Department of Emergency and Critical Care Medicine, Juntendo University, Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan. Yhirano@nshs.edu.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Hirano
authors.affiliation: Department of Surgery, Hofstra North Shore-LIJ School of Medicine and Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA. Mazizl@nshs.edu.
authors.forename: Monowar
authors.initials: M
authors.lastname: Aziz
authors.affiliation: Department of Surgery, Hofstra North Shore-LIJ School of Medicine and Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA. WLYang@nshs.edu.
authors.forename: Weng-Lang
authors.initials: WL
authors.lastname: Yang
authors.affiliation: Department of Surgery, Hofstra North Shore-LIJ School of Medicine and Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA. ZWang@nshs.edu.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Surgery, Hofstra North Shore-LIJ School of Medicine and Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA. MZhou@nshs.edu.
authors.forename: Mian
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Department of Surgery, Hofstra North Shore-LIJ School of Medicine and Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA. MOchani@nshs.edu.
authors.forename: Mahendar
authors.initials: M
authors.lastname: Ochani
authors.affiliation: Department of Surgery, Hofstra North Shore-LIJ School of Medicine and Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA. AKhader@nshs.edu.
authors.forename: Adam
authors.initials: A
authors.lastname: Khader
authors.affiliation: Department of Surgery, Hofstra North Shore-LIJ School of Medicine and Center for Translational Research, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA. pwang@nshs.edu.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
mesh_terms: D055371:Acute Lung Injury / Q000209:etiology / Q000276:immunology* / Q000517:prevention & control; D000818:Animals; D057134:Antibodies, Neutralizing / Q000627:therapeutic use*; D002465:Cell Movement; D004195:Disease Models, Animal; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008297:Male; D051379:Mice; D009504:Neutrophils / Q000502:physiology*; D053495:Osteopontin / Q000037:antagonists & inhibitors / Q000276:immunology*; D018805:Sepsis / Q000150:complications*
chemical_list: D057134:Antibodies, Neutralizing; D018836:Inflammation Mediators; D053495:Osteopontin