title: Comparative analysis of mesenchymal stem cell and embryonic tendon progenitor cell response to embryonic tendon biochemical and mechanical factors.
abstract: BACKGROUND
  Advances in tendon engineering with mesenchymal stem cells (MSCs) are hindered by a need for cues to direct tenogenesis, and markers to assess tenogenic state. We examined the effects of factors involved in embryonic tendon development on adult MSCs, and compared MSC responses to that of embryonic tendon progenitor cells (TPCs), a model system of tenogenically differentiating cells.
  
  
  METHODS
  Murine MSCs and TPCs subjected to cyclic tensile loading, transforming growth factor-β2 (TGFβ2), and fibroblast growth factor-4 (FGF4) in vitro were assessed for proliferation and mRNA levels of scleraxis, TGFβ2, tenomodulin, collagen type I and elastin.
  
  
  RESULTS
  Before treatment, scleraxis and elastin levels in MSCs were lower than in TPCs, while other tendon markers expressed at similar levels in MSCs as TPCs. TGFβ2 alone and combined with loading were tenogenic based on increased scleraxis levels in both MSCs and TPCs. Loading alone had minimal effect. FGF4 downregulated tendon marker levels in MSCs but not in TPCs. Select tendon markers were not consistently upregulated with scleraxis, demonstrating the importance of characterizing a profile of markers.
  
  
  CONCLUSIONS
  Similar responses as TPCs to specific treatments suggest MSCs have tenogenic potential. Potentially shared mechanisms of cell function between MSCs and TPCs should be investigated in longer term studies.
authors.affiliation: Department of Biomedical Engineering Tufts University, Science and Technology Center, 4 Colby Street , Medford, MA, 02155, USA. Jeffrey.Brown@tufts.edu.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Brown
authors.affiliation: Department of Biomedical Engineering Tufts University, Science and Technology Center, 4 Colby Street , Medford, MA, 02155, USA. Thomas.Galassi@tufts.edu.
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Galassi
authors.affiliation: Department of Biomedical Engineering Tufts University, Science and Technology Center, 4 Colby Street , Medford, MA, 02155, USA. Matteo.Stoppato@tufts.edu.
authors.forename: Matteo
authors.initials: M
authors.lastname: Stoppato
authors.affiliation: Department of Biomedical Engineering Tufts University, Science and Technology Center, 4 Colby Street , Medford, MA, 02155, USA. Nathan.Schiele@tufts.edu.
authors.forename: Nathan R
authors.initials: NR
authors.lastname: Schiele
authors.affiliation: Department of Biomedical Engineering Tufts University, Science and Technology Center, 4 Colby Street , Medford, MA, 02155, USA. CatherineK.Kuo@tufts.edu.|Cell, Molecular & Developmental Biology Program Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 145 Harrison Avenue, Boston, MA, 02111, USA. CatherineK.Kuo@tufts.edu.
authors.forename: Catherine K
authors.initials: CK
authors.lastname: Kuo
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D004549:Elastin / Q000235:genetics / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051519:Fibroblast Growth Factor 4 / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000494:pharmacology; D013710:Tendons / Q000166:cytology*; D013718:Tensile Strength; D059467:Transcriptome / Q000187:drug effects; D053781:Transforming Growth Factor beta2 / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D024042:Collagen Type I; D004549:Elastin; D051519:Fibroblast Growth Factor 4; D008565:Membrane Proteins; D011994:Recombinant Proteins; D053781:Transforming Growth Factor beta2; C503815:Scx protein, mouse; C486026:Tnmd protein, mouse