title: Implantation of low-level laser irradiated mesenchymal stem cells into the infarcted rat heart is associated with reduction in infarct size and enhanced angiogenesis.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the possible beneficial effects of implantation of laser-irradiated mesenchymal stem cells (MSCs) into the infarcted rat heart.
  
  
  BACKGROUND
  It was demonstrated that low-level laser therapy (LLLT) upregulates cytoprotective factors in ischemic tissues.
  
  
  METHODS
  MSCs were isolated from rat bone marrow and grown in culture. The cells were laser irradiated with a Ga-Al-As laser (810 nm wavelength), labeled with 5-bromo-2'deoxyuridine (BrdU), and then implanted into infarcted rat hearts. Non-irradiated cells were similarly labeled and acted as controls. Hearts were excised 3 wk later and cells were stained for BrdU and c-kit immunoreactivity.
  
  
  RESULTS
  Infarcted hearts that were implanted with laser-treated cells showed a significant reduction of 53% in infarct size compared to hearts that were implanted with non-laser-treated cells. The hearts implanted with laser-treated cells prior to implantation demonstrated a 5- and 6.3-fold significant increase in cell density that positively immunoreacted to BrdU and c-kit, respectively, as compared to hearts implanted with non-laser-treated cells. A significantly 1.4- and 2-fold higher level of angiogenesis and vascular endothelial growth factor, respectively, were observed in infarcted hearts that were implanted with laser-treated cells compared to non-laser-treated implanted cells.
  
  
  CONCLUSIONS
  The findings of the present study provide the first evidence that LLLT can significantly increase survival and/or proliferation of MSCs post-implantation into the ischemic/infarcted heart, followed by a marked reduction of scarring and enhanced angiogenesis. The mechanisms associated with this phenomenon remain to be elucidated in further studies.
authors.affiliation: Department of Zoology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Hana
authors.initials: H
authors.lastname: Tuby
authors.forename: Lidya
authors.initials: L
authors.lastname: Maltz
authors.forename: Uri
authors.initials: U
authors.lastname: Oron
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D028022:Low-Level Light Therapy; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000528:radiation effects*; D009203:Myocardial Infarction / Q000628:therapy*; D018919:Neovascularization, Physiologic; D051381:Rats