title: High, but not low, molecular weight hyaluronan prevents T-cell-mediated liver injury by reducing proinflammatory cytokines in mice.
abstract: BACKGROUND
  The extracellular matrix component hyaluronan (HA) modulates the production of various cytokines and chemokines by activated inflammatory cells. In this study, we investigated whether exogenous administration of HA influences T-cell-mediated liver injury and cytokine production.
  
  
  METHODS
  Liver injury was induced by administration of concanavalin A (Con A) or D-galactosamine/lipopolysaccharide (GalN/LPS), and 0.05%-0.35% (v/v) HA (MW 250, 470, 780, 900, and 1200 kDa) was administered intravenously 18 h before Con A or GalN/LPS injection. Plasma ALT level was determined enzymatically and plasma cytokine levels were determined by ELISA.
  
  
  RESULTS
  The elevated plasma levels of ALT at 8 h after Con A and at 7 h after GalN/LPS injection were significantly decreased by pretreatment with high molecular weight HAs (780, 900, and 1200 kDa) but not low molecular weight HAs (250 and 470 kDa). High molecular weight HA (900 kDa) significantly reduced plasma tumor necrosis factor-alpha, interferon gamma, macrophage inflammatory protein 2, and interleukin 4 levels after Con A injection. However, this inhibitory effect on plasma cytokines was not observed with low molecular weight HA (250 kDa) pretreatment.
  
  
  CONCLUSIONS
  The present results suggest that high molecular weight but not low molecular weight HA prevents liver injury by reducing proinflammatory cytokines in a T-cell-mediated liver injury model. The extracellular matrix component hyaluronan (HA) modulates the production of various cytokines and chemokines by activated inflammatory cells. In this study, we investigated whether exogenous administration of HA influences T-cell-mediated liver injury and cytokine production.
authors.affiliation: Second Department of Internal Medicine, Asahikawa Medical College, 2-1-1-1 Midorigaoka Higashi, Asahikawa 078-8510, Japan.
authors.forename: Kimihide
authors.initials: K
authors.lastname: Nakamura
authors.forename: Shiro
authors.initials: S
authors.lastname: Yokohama
authors.forename: Masashi
authors.initials: M
authors.lastname: Yoneda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Okamoto
authors.forename: Yohosui
authors.initials: Y
authors.lastname: Tamaki
authors.forename: Taku
authors.initials: T
authors.lastname: Ito
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Okada
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Aso
authors.forename: Isao
authors.initials: I
authors.lastname: Makino
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D056486:Chemical and Drug Induced Liver Injury; D003208:Concanavalin A / Q000009:adverse effects; D016207:Cytokines / Q000276:immunology; D005260:Female; D005688:Galactosamine / Q000009:adverse effects; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D008070:Lipopolysaccharides / Q000009:adverse effects; D008107:Liver Diseases / Q000276:immunology* / Q000517:prevention & control*; D008297:Male; D051379:Mice; D023421:Models, Animal; D008970:Molecular Weight; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D016207:Cytokines; D008070:Lipopolysaccharides; D003208:Concanavalin A; D005688:Galactosamine; D006820:Hyaluronic Acid