title: Hyaluronan reversed proteoglycan synthesis inhibited by mechanical stress: possible involvement of antioxidant effect.
abstract: BACKGROUND
  Abnormal mechanical stress loaded on the cartilage leads to the osteoarthritis (OA). Although intraarticular hyaluronan (HA) injection is an effective treatment for OA, the underlying mechanism has not been made clear.
  
  
  METHODS
  Mechanical compression was loaded on the bovine cartilage using the Biopress system. Proteoglycan (PG) and reactive oxygen species (ROS) synthesis were measured with [(35)S] incorporation and fluorescent dye, respectively. Accumulation of peroxynitrite was determined with western blotting using nitrotyrosine antibody.
  
  
  RESULTS
  Mechanical compression inhibited PG synthesis and enhanced ROS. Externally added HA reversed stress-inhibited PG synthesis and attenuated ROS synthesis. HA also significantly decreased the generation of nitrotyrosine.
  
  
  CONCLUSIONS
  HA neutralized stress-enhanced ROS synthesis and resulted in the reversing of PG synthesis. These data suggest that HA plays an anabolic effect as an antioxidant.
authors.affiliation: Department of Orthopaedic Surgery, Kinki University School of Medicine, Osaka, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Miki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Teramura
authors.forename: Takashi
authors.initials: T
authors.lastname: Tomiyama
authors.forename: Yuta
authors.initials: Y
authors.lastname: Onodera
authors.forename: Toshiki
authors.initials: T
authors.lastname: Matsuoka
authors.forename: Kanji
authors.initials: K
authors.lastname: Fukuda
authors.forename: Chiaki
authors.initials: C
authors.lastname: Hamanishi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D015153:Blotting, Western; D002356:Cartilage / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D002417:Cattle; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism; D017931:DNA Primers; D006820:Hyaluronic Acid / Q000494:pharmacology*; D049449:Luminescence; D009569:Nitric Oxide / Q000378:metabolism; D009924:Organ Culture Techniques; D030421:Peroxynitrous Acid / Q000378:metabolism; D011509:Proteoglycans / Q000096:biosynthesis* / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013314:Stress, Mechanical; D013462:Sulfur Radioisotopes; D013481:Superoxides / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D000975:Antioxidants; D017931:DNA Primers; D011509:Proteoglycans; D017382:Reactive Oxygen Species; D013462:Sulfur Radioisotopes; D013481:Superoxides; D030421:Peroxynitrous Acid; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D006820:Hyaluronic Acid