title: CTGF positively regulates BMP12 induced tenogenic differentiation of tendon stem cells and signaling.
abstract: OBJECTIVE
  Disordered differentiation of tendon stem cells (TSCs) during repair of injured tendon can result in the pathogenesis of chronic tendinopathy. Understanding tenocyte differentiation may provide new therapeutic insights for the prevention and treatment of chronic tendinopathy. The aim of our study was to determine if CTGF exerts a similar effect on BMP12-driven differentiation of rat TSCs.
  
  
  METHODS
  In overexpressing and RNA interference CTGF TSCs, tenogenic differentitation and the expression of related genes were determined by immunofluorescence staining, quantitative PCR, and western blotting, with or without BMP12 treatment. The interaction in vitro between CTGF and BMP12 was detected by Chemical crosslinking assay.
  
  
  RESULTS
  Our results showed that BMP12 effectively increased the expression of the tenocyte lineage markers scleraxis (Scx) and tenomodulin (Tnmd) at both mRNA and protein levels. Over-expression of CTGF from a lentiviral vector increased the expression of Scx and Tnmd as well as tendon proteins type I collagen (ColI) and tenascin-C (Tn-C) in TSCs compared to non-treated control cells with or without simultaneous BMP12 stimulation. Knockdown of CTGF expression decreased the expression of Scx, Tnmd, ColI and Tn-C compared to control cells. Chemical crosslinking experiments demonstrated a direct interaction between CTGF and BMP12.
  
  
  CONCLUSIONS
  In conclusion, BMP12 plays a crucial role in tenogenesis via the Smad1/5/8 pathway, and CTGF positively promotes this effect.
authors.affiliation: Department of Orthopaedics, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Junpeng
authors.initials: J
authors.lastname: Liu
authors.forename: Xu
authors.initials: X
authors.lastname: Tao
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Weifeng
authors.initials: W
authors.lastname: Han
authors.forename: You
authors.initials: Y
authors.lastname: Zhou
authors.forename: Kanglai
authors.initials: K
authors.lastname: Tang
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D019070:Cell Lineage; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D055513:Connective Tissue Growth Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D055412:Growth Differentiation Factors / Q000494:pharmacology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D034622:RNA Interference; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects*; D051898:Smad1 Protein / Q000378:metabolism; D051902:Smad5 Protein / Q000378:metabolism; D051904:Smad8 Protein / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D019063:Tenascin / Q000378:metabolism; D013710:Tendons / Q000166:cytology
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D024042:Collagen Type I; D055513:Connective Tissue Growth Factor; D055412:Growth Differentiation Factors; D008565:Membrane Proteins; D051898:Smad1 Protein; D051902:Smad5 Protein; D051904:Smad8 Protein; D019063:Tenascin; C526316:CCN2 protein, rat; C503819:Scx protein, rat; C486027:Tnmd protein, rat