title: Hydrostatic pressure modulates proteoglycan metabolism in chondrocytes seeded in agarose.
abstract: OBJECTIVE
  To investigate the effect of isolated hydrostatic pressure on proteoglycan metabolism in chondrocytes.
  
  
  METHODS
  Bovine articular chondrocytes cultured in agarose gels were subjected to 5 MPa hydrostatic pressure for 4 hours in either a static or a pulsatile (1 Hz) mode, and changes in glycosaminoglycan (GAG) synthesis, hydrodynamic size, and aggregation properties of proteoglycans and aggrecan messenger RNA (mRNA) levels were determined.
  
  
  RESULTS
  The application of 5 MPa static pressure caused a significant increase in GAG synthesis of 11% (P < 0.05). Column chromatography showed that this increase in GAG synthesis was associated with large proteoglycans. In addition, semiquantitative reverse transcriptase-polymerase chain reaction showed a 4-fold increase in levels of aggrecan mRNA (P < 0.01).
  
  
  CONCLUSIONS
  Hydrostatic pressure in isolation, which does not cause cell deformation, can affect proteoglycan metabolism in chondrocytes cultured in agarose gels, indicating an important role of hydrostatic pressure in the regulation of extracellular matrix turnover in articular cartilage.
authors.affiliation: Keio University, Tokyo, Japan. tttoyoda@sc.itc.keio.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Toyoda
authors.forename: Bahaa B
authors.initials: BB
authors.lastname: Seedhom
authors.forename: Jian Q
authors.initials: JQ
authors.lastname: Yao
authors.forename: Jennifer
authors.initials: J
authors.lastname: Kirkham
authors.forename: Steven
authors.initials: S
authors.lastname: Brookes
authors.forename: William A
authors.initials: WA
authors.lastname: Bonass
mesh_terms: D053674:Aggrecans; D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods; D002470:Cell Survival; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D016326:Extracellular Matrix Proteins; D005260:Female; D006025:Glycosaminoglycans / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006874:Hydrostatic Pressure; D037181:Lectins, C-Type; D010100:Oxygen / Q000378:metabolism; D010641:Phenotype; D011509:Proteoglycans / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012685:Sepharose
chemical_list: D053674:Aggrecans; D016326:Extracellular Matrix Proteins; D006025:Glycosaminoglycans; D037181:Lectins, C-Type; D011509:Proteoglycans; D012333:RNA, Messenger; D002245:Carbon Dioxide; D012685:Sepharose; D010100:Oxygen