title: Indian hedgehog gene transfer is a chondrogenic inducer of human mesenchymal stem cells.
abstract: BACKGROUND
  To date, no single most-appropriate factor or delivery method has been identified for the purpose of mesenchymal stem cell (MSC)-based treatment of cartilage injury. Therefore, in this study we tested whether gene delivery of the growth factor Indian hedgehog (IHH) was able to induce chondrogenesis in human primary MSCs, and whether it was possible by such an approach to modulate the appearance of chondrogenic hypertrophy in pellet cultures in vitro.
  
  
  METHODS
  First-generation adenoviral vectors encoding the cDNA of the human IHH gene were created by cre-lox recombination and used alone or in combination with adenoviral vectors, bone morphogenetic protein-2 (Ad.BMP-2), or transforming growth factor beta-1 (Ad.TGF-β1) to transduce human bone-marrow derived MSCs at 5 × 10² infectious particles/cell. Thereafter, 3 × 10⁵ cells were seeded into aggregates and cultured for 3 weeks in serum-free medium, with untransduced or marker gene transduced cultures as controls. Transgene expressions were determined by ELISA, and aggregates were analysed histologically, immunohistochemically, biochemically and by RT-PCR for chondrogenesis and hypertrophy.
  
  
  RESULTS
  IHH, TGF-β1 and BMP-2 genes were equipotent inducers of chondrogenesis in primary MSCs, as evidenced by strong staining for proteoglycans, collagen type II, increased levels of glycosaminoglycan synthesis, and expression of mRNAs associated with chondrogenesis. IHH-modified aggregates, alone or in combination, also showed a tendency to progress towards hypertrophy, as judged by the expression of alkaline phosphatase and stainings for collagen type X and Annexin 5.
  
  
  CONCLUSIONS
  As this study provides evidence for chondrogenic induction of MSC aggregates in vitro via IHH gene delivery, this technology may be efficiently employed for generating cartilaginous repair tissues in vivo.
authors: Andre F
authors: AF
authors: Steinert
authors: Manuel
authors: M
authors: Weissenberger
authors: Manuela
authors: M
authors: Kunz
authors: Fabian
authors: F
authors: Gilbert
authors: Steven C
authors: SC
authors: Ghivizzani
authors: Sascha
authors: S
authors: Göbel
authors: Franz
authors: F
authors: Jakob
authors: Ulrich
authors: U
authors: Nöth
authors: Maximilian
authors: M
authors: Rudert
mesh_terms: D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D020219:Chondrogenesis / Q000502:physiology*; D005260:Female; D018014:Gene Transfer Techniques; D053823:Hedgehog Proteins / Q000235:genetics*; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D008875:Middle Aged
chemical_list: D053823:Hedgehog Proteins; C509246:IHH protein, human