title: Osteogenic Protein-1 inhibits matrix depletion in a hyaluronan hexasaccharide-induced model of osteoarthritis.
abstract: OBJECTIVE
  To examine the capacity of recombinant osteogenic protein-1 (OP-1) to inhibit the cartilage extracellular matrix damage that follows treatment with hyaluronan hexasaccharides (HA6).
  
  
  METHODS
  The effects of OP-1 were examined on isolated human chondrocytes grown in alginate beads as well as articular cartilage slices treated with hyaluronan hexasaccharides. Changes in the relative expression of messenger RNA for hyaluronan synthase- 2, aggrecan and CD44 were determined by competitive quantitative reverse transcriptase-polymerase chain reaction. Cartilage proteoglycan biosynthesis was examined by a (35)S-sulfate incorporation assay. Cell-associated matrix of human chondrocytes was visualized by the use of particle exclusion assay, and alcian blue staining. Cartilage slices were examined for accumulation of proteoglycan by Safranin-O, and hyaluronan by a specific biotinylated probe.
  
  
  RESULTS
  Combined OP-1 and HA6 treatment resulted in enhanced expression of mRNA for aggrecan and HAS-2, compared to the treatment with HA6 only. This increased expression of aggrecan mRNA was paralleled by an increased synthesis of cartilage proteoglycan especially retained in the cell-associated matrix. Co-treatment with OP-1 inhibited the HA6-induced depletion of cell-associated matrices as well as HA6-induced depletion of hyaluronan and proteoglycan within cartilage tissue slices.
  
  
  CONCLUSIONS
  These results demonstrate that OP-1 can abrogate the catabolic events associated with a HA6-induced matrix depletion model of osteoarthritis. The mRNA levels of two major cartilage extracellular matrix components, aggrecan and hyaluronan synthase-2 are enhanced above values obtained by either OP-1 or HA6 treatments alone.
authors.affiliation: Department of Biochemistry, Rush Medical College, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, IL 60612, USA.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nishida
authors.forename: Cheryl B
authors.initials: CB
authors.lastname: Knudson
authors.forename: Warren
authors.initials: W
authors.lastname: Knudson
mesh_terms: D030201:Activin Receptors, Type I; D000328:Adult; D000368:Aged; D053674:Aggrecans; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D002358:Cartilage, Articular / Q000378:metabolism*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D000076002:Hyaluronan Synthases; D006820:Hyaluronic Acid / Q000633:toxicity*; D037181:Lectins, C-Type; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism*; D011506:Proteins / Q000494:pharmacology*; D011509:Proteoglycans / Q000096:biosynthesis / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D014166:Transferases / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D053674:Aggrecans; C525819:BMP7 protein, human; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D016326:Extracellular Matrix Proteins; D018960:Hyaluronan Receptors; D037181:Lectins, C-Type; D011506:Proteins; D011509:Proteoglycans; D016212:Transforming Growth Factor beta; D012313:RNA; D006820:Hyaluronic Acid; D014166:Transferases; D014453:Glucuronosyltransferase; C101754:HAS2 protein, human; D000076002:Hyaluronan Synthases; C425423:ACVR1 protein, human; D030201:Activin Receptors, Type I