title: BMP-2 and BMP-7 affect human rotator cuff tendon cells in vitro.
abstract: BACKGROUND
  Rotator cuff repair is prone to incomplete regeneration. To explore biological improvements of tendon-bone healing, it was the aim of this study to investigate the influence of growth factors bone morphogenetic protein (BMP)-2 and BMP-7 on tenocyte cell activity and matrix gene expression and production. A beneficial effect of these factors would be promising to improve tendon-bone healing in vivo.
  
  
  METHODS
  Tenocyte-like cells were isolated from human rotator cuff tissue samples (supraspinatus and long head of biceps tendon) and incubated with BMP-2 (100-1000 ng/mL) and BMP-7 (100-2000 ng/mL), both alone and in combination. At days 0, 3, and 6, cell activity was assessed. At day 6, collagen type I production and the expression of several tendon-, bone-, and cartilage-related markers (collagen types I-III, osteocalcin, scleraxis) were evaluated.
  
  
  RESULTS
  Dose-dependent effects of both investigated growth factors on tenocyte-like cells were observed. Application of BMP-2 increased collagen type I production significantly but its expression only slightly. Cell activity was decreased in higher doses over time. For BMP-7, a significant increase in collagen type I production and expression, as well as increased cell activity, was observed. The addition of both factors resulted in decreased parameters when compared with BMP-7 alone. The expression of collagen types II and III, osteocalcin, and scleraxis was not significantly affected by application of BMPs.
  
  
  CONCLUSIONS
  Besides the well-known effects of BMP-2 and BMP-7 on osteoblasts, this study describes further effects on rotator cuff tendon cell biology. Both tissue types potentially need to be addressed to improve tendon-bone healing of the rotator cuff.
authors: Julius Wolff Institut, Center for Musculoskeletal Surgery, Charité-Universitätsmedizin, Berlin, Germany. stephan.pauly@charite.de
authors: Stephan
authors: S
authors: Pauly
authors: Franka
authors: F
authors: Klatte
authors: Catrin
authors: C
authors: Strobel
authors: Gerhard
authors: G
authors: Schmidmaier
authors: Stefan
authors: S
authors: Greiner
authors: Markus
authors: M
authors: Scheibel
authors: Britt
authors: B
authors: Wildemann
mesh_terms: D000368:Aged; D055396:Bone Morphogenetic Protein 2 / Q000502:physiology*; D055419:Bone Morphogenetic Protein 7 / Q000502:physiology*; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D008875:Middle Aged; D015675:Osteocalcin / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D017006:Rotator Cuff / Q000166:cytology*; D014945:Wound Healing / Q000502:physiology*
chemical_list: D055396:Bone Morphogenetic Protein 2; D055419:Bone Morphogenetic Protein 7; D010446:Peptide Fragments; D015675:Osteocalcin; C471083:Col-1 peptide, human; D020778:Matrix Metalloproteinase 2