title: Purified human plasma glycosaminoglycans reduced NF-kappaB activation, pro-inflammatory cytokine production and apoptosis in LPS-treated chondrocytes.
abstract: BACKGROUND
  There have been several cases reporting a significant increase in chondroitin sulphate plasma levels in patients with different types of disease, such as systemic lupus erythematosus, rheumatoid arthritis, and liver disease. At present, the precise role of chondroitin sulphate molecules in blood is unclear. Previous investigations have shown that the addition of purified human plasma glycosaminoglycans (GAGs), containing a high percentage of chondroitin-4-sulphate (C4S) was able to inhibit lipid peroxidation and to protect cells from reactive oxygen species damage, suggesting antioxidant activity. Starting from these reports, the aim of this study was to evaluate the effectiveness of GAG structures purified from normal human plasma in reducing inflammation using a model of lipopolysaccharide (LPS)-induced increase of pro-inflammatory cytokines in mouse articular chondrocyte cultures.
  
  
  RESULTS
  Chondrocyte stimulation with LPS (50 microg/ml) for 24 h enhanced gene expression of tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1beta), interleukin 6 (IL-6), interferon gamma (IFN-gamma), inducible nitric oxide synthase (iNOS) and increases in their related protein levels, as well as NF-kappaB activation, IkappaBalpha phosphorylation and apoptosis evaluated by the increase in caspase-3 expression and its related protein amount. LPS treatment also generated a high amount of nitric oxide (NO). The addition of different doses of purified human GAGs to LPS-stimulated chondrocytes reduced inflammatory cytokines and iNOS both at mRNA and protein levels, blocked NF-kappaB activation and cytoplasmic IkappaBalpha phosphorylation, limited cell death by inhibiting apoptosis, and reduced NO concentrations.
  
  
  CONCLUSIONS
  These results further support the hypothesis that plasma GAGs may function as immunomodulators and their increased release and degradation could be a biological response acting to modulate inflammation during disease.
authors.affiliation: Department of Biochemical, Physiological and Nutritional Sciences, Section of Medical Chemistry, School of Medicine, University of Messina, Messina, Italy. gcampo@unime.it
authors.forename: Giuseppe M
authors.initials: GM
authors.lastname: Campo
authors.forename: Angela
authors.initials: A
authors.lastname: Avenoso
authors.forename: Salvatore
authors.initials: S
authors.lastname: Campo
authors.forename: Angela
authors.initials: A
authors.lastname: D'Ascola
authors.forename: Paola
authors.initials: P
authors.lastname: Traina
authors.forename: Dario
authors.initials: D
authors.lastname: Samà
authors.forename: Alberto
authors.initials: A
authors.lastname: Calatroni
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D002809:Chondroitin Sulfates / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects / Q000276:immunology; D007155:Immunologic Factors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000737:chemistry / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000235:genetics / Q000276:immunology*; D009569:Nitric Oxide / Q000276:immunology / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D016207:Cytokines; D007155:Immunologic Factors; D008070:Lipopolysaccharides; D016328:NF-kappa B; D009569:Nitric Oxide; D002809:Chondroitin Sulfates