title: Differential effect of molecular size HA in mouse chondrocytes stimulated with PMA.
abstract: BACKGROUND
  Hyaluronan (HA) fragments elicit the expression of inflammatory mediators through a mechanism involving the CD44 receptor. This study investigated the effects of HA at different molecular weights on PMA-induced inflammation in mouse chondrocytes.
  
  
  METHODS
  mRNA and related protein levels were measured for CD44, PKCdelta, PKCepsilon, TNF-alpha, IL-1beta, MMP-13, and iNOS in chondrocytes, untreated or PMA treated, with and without the addition of HA. The level of NF-kB activation was also assayed.
  
  
  RESULTS
  CD44, PKCdelta, and PKCepsilon mRNA expression resulted higher than controls in chondrocytes treated with PMA. PMA also induced NF-kB up-regulation and increased TNF-alpha, IL-1beta, MMP-13, and iNOS expression. HA treatment produced different effects: low MW HA up-regulated CD44 expression, increased PKCdelta and PKCepsilon levels, and enhanced inflammation in untreated chondrocytes; while in PMA-treated cells it increased CD44, PKCdelta, PKCepsilon, NF-kB, TNF-alpha, IL-1beta, MMP-13, and iNOS expression and enhanced the effects of PMA; medium MW HA did not exert action; high MW HA had no effect on untreated chondrocytes; however, it reduced PKCdelta, PKCepsilon, NF-kB activation and inflammation in PMA-stimulated cells. Specific CD44 blocking antibody was utilised to confirm CD44 as the target of HA modulation.
  
  
  CONCLUSIONS
  These data suggest that HA via CD44 may modulate inflammation via its different molecular mass.
authors.affiliation: Department of Biochemical, Physiological and Nutritional Sciences, section of Medical Chemistry, School of Medicine, University of Messina, Policlinico Universitario, Torre Biologica, 5 degrees piano, Via C. Valeria, 98125, 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: Alberto
authors.initials: A
authors.lastname: Calatroni
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D015153:Blotting, Western; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D018960:Hyaluronan Receptors / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D006820:Hyaluronic Acid / Q000737:chemistry / Q000494:pharmacology*; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D008970:Molecular Weight; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D051745:Protein Kinase C-delta / Q000235:genetics / Q000378:metabolism; D051744:Protein Kinase C-epsilon / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D000906:Antibodies; D018960:Hyaluronan Receptors; D053583:Interleukin-1beta; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D006820:Hyaluronic Acid; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C497259:Prkcd protein, mouse; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; D053509:Matrix Metalloproteinase 13; D013755:Tetradecanoylphorbol Acetate