title: Adipose-derived mesenchymal stem cells treated with growth differentiation factor-5 express tendon-specific markers.
abstract: OBJECTIVE
  Adipose-derived mesenchymal stem cells (ADMSCs) are a unique population of stem cells with therapeutic potential in the treatment of connective tissue injuries. Growth differentiation factor-5 (GDF)-5 is known to play a role in tendon repair and maintenance. The aim of this study was to investigate the effects of GDF-5 on proliferation and tendonogenic gene expression of rat ADMSCs.
  
  
  METHODS
  ADMSCs were treated in culture with different concentrations of GDF-5 (0-1000 ng/mL) for 12 days. Biochemical, temporal, and concentration kinetic studies were done. Extracellular matrix (ECM) synthesis, tendonogenic differentiation, and matrix remodeling gene and protein expression were analyzed.
  
  
  RESULTS
  GDF-5 led to increased ADMSC proliferation in a dose- and time-dependent manner. ADMSCs demonstrated enhanced ECM (collagen type I, decorin, and aggrecan) and tendonogenic marker (scleraxis, tenomodulin, and tenascin-C) gene expression with 100 ng/mL of GDF-5 (p < 0.05). ECM and tendon-specific markers showed time-dependent increases at various time points (p < 0.05), although decorin decreased at day 9 (p < 0.05). GDF-5 did alter expression of matrix remodeling genes, with no specific trends observed. Western blot analysis confirmed dose- and time-dependent increases in protein expression of tenomodulin, tenascin-C, Smad-8, and matrix metalloproteinase-13.
  
  
  CONCLUSIONS
  In vitro GDF-5 treatment can induce cellular events leading to the tendonogenic differentiation of ADMSCs. The use of combined GDF-5 and ADMSCs tissue-engineered therapies may have a role in the future of tendon repair.
authors.affiliation: Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Park
authors.forename: Macalus V
authors.initials: MV
authors.lastname: Hogan
authors.forename: Girish S
authors.initials: GS
authors.lastname: Kesturu
authors.forename: Roshan
authors.initials: R
authors.lastname: James
authors.forename: Gary
authors.initials: G
authors.lastname: Balian
authors.forename: Abhinav Bobby
authors.initials: AB
authors.lastname: Chhabra
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D053674:Aggrecans / Q000378:metabolism; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism*; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D024042:Collagen Type I / Q000378:metabolism; D058575:Decorin / Q000378:metabolism; D055428:Growth Differentiation Factor 5 / Q000494:pharmacology*; D053509:Matrix Metalloproteinase 13 / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D051381:Rats; D011916:Rats, Inbred F344; D019063:Tenascin / Q000378:metabolism; D013710:Tendons / Q000378:metabolism*
chemical_list: D053674:Aggrecans; D051792:Basic Helix-Loop-Helix Proteins; D015415:Biomarkers; D024042:Collagen Type I; D058575:Decorin; D055428:Growth Differentiation Factor 5; D053509:Matrix Metalloproteinase 13; D008565:Membrane Proteins; D019063:Tenascin; C503819:Scx protein, rat; C486027:Tnmd protein, rat