title: In vivo cardiac cellular reprogramming efficacy is enhanced by angiogenic preconditioning of the infarcted myocardium with vascular endothelial growth factor.
abstract: BACKGROUND
  In situ cellular reprogramming offers the possibility of regenerating functional cardiomyocytes directly from scar fibroblasts, obviating the challenges of cell implantation. We hypothesized that pretreating scar with gene transfer of the angiogenic vascular endothelial growth factor (VEGF) would enhance the efficacy of this strategy.
  
  
  RESULTS
  Gata4, Mef2c, and Tbx5 (GMT) administration via lentiviral transduction was demonstrated to transdifferentiate rat fibroblasts into (induced) cardiomyocytes in vitro by cardiomyocyte marker studies. Fisher 344 rats underwent coronary ligation and intramyocardial administration of an adenovirus encoding all 3 major isoforms of VEGF (AdVEGF-All6A(+)) or an AdNull control vector (n=12/group). Lentivirus encoding GMT or a GFP control was administered to each animal 3 weeks later, followed by histologic and echocardiographic analyses. GMT administration reduced the extent of fibrosis by half compared with GFP controls (12 ± 2% vs 24 ± 3%, P<0.01) and reduced the number of myofibroblasts detected in the infarct zone by 4-fold. GMT-treated animals also demonstrated greater density of cardiomyocyte-specific marker beta myosin heavy chain 7(+) cells compared with animals receiving GFP with or without VEGF (P<0.01). Ejection fraction was significantly improved after GMT vs GFP administration (12 ± 3% vs -7 ± 3%, P<0.01). Eight (73%) GFP animals but no GMT animals demonstrated decreased ejection fraction during this interval (P<0.01). Also, improvement in ejection fraction was 4-fold greater in GMT/VEGF vs GMT/null animals (17 ± 2% vs 4 ± 1%, P<0.05).
  
  
  CONCLUSIONS
  VEGF administration to infarcted myocardium enhances the efficacy of GMT-mediated cellular reprogramming in improving myocardial function and reducing the extent of myocardial fibrosis compared with the use of GMT or VEGF alone.
authors: Department of Surgery, Stony Brook University Medical Center, Stony Brook, NY, USA.
authors: Megumi
authors: M
authors: Mathison
authors: Robert P
authors: RP
authors: Gersch
authors: Ahmed
authors: A
authors: Nasser
authors: Sarit
authors: S
authors: Lilo
authors: Mallory
authors: M
authors: Korman
authors: Mitchell
authors: M
authors: Fourman
authors: Neil
authors: N
authors: Hackett
authors: Kenneth
authors: K
authors: Shroyer
authors: Jianchang
authors: J
authors: Yang
authors: Yupo
authors: Y
authors: Ma
authors: Ronald G
authors: RG
authors: Crystal
authors: Todd K
authors: TK
authors: Rosengart
mesh_terms: D000818:Animals; D004359:Drug Therapy, Combination; D004452:Echocardiography; D005355:Fibrosis / Q000517:prevention & control; D005455:Fluorescent Antibody Technique; D050991:GATA4 Transcription Factor / Q000008:administration & dosage; D018014:Gene Transfer Techniques; D064326:MEF2 Transcription Factors; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000502:physiology; D018006:Myogenic Regulatory Factors / Q000008:administration & dosage; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D020825:T-Box Domain Proteins / Q000008:administration & dosage; D014157:Transcription Factors / Q000008:administration & dosage*; D014162:Transfection; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000008:administration & dosage*; D016276:Ventricular Function / Q000187:drug effects / Q000502:physiology*
chemical_list: D050991:GATA4 Transcription Factor; D064326:MEF2 Transcription Factors; C578042:MEF2C protein, rat; D018006:Myogenic Regulatory Factors; D020825:T-Box Domain Proteins; C103172:T-box transcription factor 5; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A
keywords: angiogenesis; gene therapy; myocardial infarction; stem cells