title: Direct FGF-2 gene transfer via recombinant adeno-associated virus vectors stimulates cell proliferation, collagen production, and the repair of experimental lesions in the human ACL.
abstract: BACKGROUND
  Basic fibroblast growth factor (FGF-2) is a powerful stimulator of fibroblast proliferation and type I/III collagen production.
  
  
  OBJECTIVE
  Overexpression of FGF-2 via direct recombinant adeno-associated virus (rAAV) vector-mediated gene transfer enhances the healing of experimental lesions to the human anterior cruciate ligament (ACL).
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  rAAV vectors carrying a human FGF-2 sequence or the lacZ marker gene were applied to primary human ACL fibroblasts in vitro and to intact or experimentally injured human ACL explants in situ to evaluate the efficacy and duration of transgene expression and the potential effects of FGF-2 treatment upon the proliferative, metabolic, and regenerative activities in these systems.
  
  
  RESULTS
  Sustained, effective dose-dependent lacZ expression was achieved in all systems tested (up to 96% ± 2% in vitro and 80%-85% in situ for at least 30 days). rAAV allowed for continuous FGF-2 production both in vitro and in the intact ACL in situ (32.7 ± 1.4 and 33.1 ± 0.8 pg/mL/24 h, respectively, ie, up to 41-fold more than in the controls at day 30; always P ≤ .001), leading to significantly and durably enhanced levels of proliferation and type I/III collagen production vis-à-vis lacZ (at least 3- and 4-fold increases at day 30, respectively; always P ≤ .001). Most notably, rAAV FGF-2 promoted a significant, long-term production of the factor in experimental ACL lesions (92.7 ± 3.9 pg/mL/24 h, ie, about 5-fold more than in the controls; P ≤ .001) associated with enhanced levels of proliferation and type I/III collagen synthesis (at least 2- and 4-fold increases at day 30, respectively; always P ≤ .001). Remarkably, the FGF-2 treatment allowed for a decrease in the amplitude of such lesions possibly because of the increased expression in contractile α-smooth muscle actin, ligament-specific transcription factor scleraxis, and nuclear factor-κB for proliferation and collagen deposition, which are all markers commonly induced in response to injury.
  
  
  CONCLUSIONS
  Efficient, stable FGF-2 expression via rAAV enhances the healing of experimental human ACL lesions by activating key cellular and metabolic processes.
  
  
  CONCLUSIONS
  This approach has potential value for the development of novel, effective treatments for ligament reconstruction.
authors.affiliation: Center of Experimental Orthopaedics, Saarland University Medical Center, Homburg, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Madry
authors.forename: Dieter
authors.initials: D
authors.lastname: Kohn
authors.forename: Magali
authors.initials: M
authors.lastname: Cucchiarini
mesh_terms: D000199:Actins / Q000378:metabolism; D000368:Aged; D016118:Anterior Cruciate Ligament / Q000166:cytology / Q000378:metabolism; D000070598:Anterior Cruciate Ligament Injuries; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation; D003094:Collagen / Q000378:metabolism; D000229:Dependovirus; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000502:physiology*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D066298:In Vitro Techniques; D007718:Knee Injuries / Q000628:therapy; D016328:NF-kappa B / Q000378:metabolism; D014945:Wound Healing
chemical_list: D000199:Actins; D051792:Basic Helix-Loop-Helix Proteins; D003094:Collagen; D016222:Fibroblast Growth Factor 2; D016328:NF-kappa B; C541116:ACTA2 protein, human; C093504:SCX protein, human