title: Utility of dual-modality bioluminescence and MRI in monitoring stem cell survival and impact on post myocardial infarct remodeling.
abstract: OBJECTIVE
  Firefly luciferase (Fluc) reporter gene is an authentic marker for surviving stem cells. However, it is unable to visualize the intramyocardial delivery of stem cells or their impact on cardiac function. The investigators demonstrate that bioluminescence imaging (BLI) combined with magnetic resonance imaging (MRI) allows better assessment of cell delivery and the impact on post-myocardial infarction remodeling.
  
  
  METHODS
  Murine embryonic stem cells (0.3 million) were double-labeled with Fluc and superparamagnetic iron oxide particles and injected into the infarct border zone of athymic rat hearts. BLI and MRI were performed serially up to 2 months after injection, followed by immunohistochemistry.
  
  
  RESULTS
  Dual-modality imaging was able to verify the initial intramyocardial delivery of the cells and their survival status. Over time, BLI signal increased in seven of nine hearts and disappeared in the other two hearts. The divergence of BLI signal over time was supported by MRI findings. Left ventricular ejection fraction and fractional shortening estimated by MRI suggested that cell engraftment mediated a positive impact on post-myocardial infarction remodeling. Two months after intramyocardial injection, superparamagnetic iron oxide-associated signals facilitated the localization of the injection site.
  
  
  CONCLUSIONS
  Dual-modality imaging has the unique ability to monitor cell delivery, survival status, graft morphology, and impact on post-myocardial infarction remodeling.
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, 19104, USA.
authors.forename: Hualei
authors.initials: H
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Qiao
authors.forename: Ashley
authors.initials: A
authors.lastname: Bakken
authors.forename: Fabao
authors.initials: F
authors.lastname: Gao
authors.forename: Bin
authors.initials: B
authors.lastname: Huang
authors.forename: Yingqiu Y
authors.initials: YY
authors.lastname: Liu
authors.forename: Wafik
authors.initials: W
authors.lastname: El-Deiry
authors.forename: Victor A
authors.initials: VA
authors.lastname: Ferrari
authors.forename: Rong
authors.initials: R
authors.lastname: Zhou
mesh_terms: D000818:Animals; D002470:Cell Survival; D003287:Contrast Media; D003911:Dextrans; D004195:Disease Models, Animal; D005260:Female; D017930:Genes, Reporter; D049409:Luciferases, Firefly; D049408:Luminescent Agents; D008163:Luminescent Measurements / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D009203:Myocardial Infarction / Q000503:physiopathology*; D051381:Rats; D011923:Rats, Nude; D013234:Stem Cells / Q000166:cytology*; D020257:Ventricular Remodeling
chemical_list: D003287:Contrast Media; D003911:Dextrans; D049408:Luminescent Agents; D058185:Magnetite Nanoparticles; D049409:Luciferases, Firefly; C065507:ferumoxides