title: Enhanced inhibition of neointimal hyperplasia by genetically engineered endothelial progenitor cells.
abstract: BACKGROUND
  Circulating endothelial progenitor cells (EPCs) have been reported previously. In this study, we examined the hypothesis that overexpression of vasculoprotective gene endothelial nitric oxide synthase (eNOS) and heme oxygenase-1 (HO-1) in EPCs enhances their ability to inhibit neointimal hyperplasia.
  
  
  RESULTS
  EPCs were isolated from rabbit peripheral blood, expanded in culture, and transduced with pseudotyped retroviral vectors expressing human eNOS (eNOS-EPCs), HO-1 (HO-1-EPCs), or green fluorescent protein (GFP-EPCs). Transduction efficiency of EPCs ex vivo was >90%. Four groups of rabbits (n=5 to 6 per group) were subjected to balloon angioplasty of the common carotid artery. Immediately after injury, approximately 5x10(6) autologous eNOS-EPCs or HO-1-EPCs were transplanted into the injured vessel. Control animals received an equivalent number of GFP-EPCs or Ringer's saline. Two weeks after transplantation, eNOS and HO-1 transgene transcripts and proteins were detected in the transduced rabbit vessels. Endothelialization was enhanced in the EPC-transplanted vessels independently of gene transfer. Neointimal thickening was significantly reduced in the GFP-EPC-treated vessels relative to the saline control. Neointima size was further reduced in vessels treated with eNOS-EPCs. Surprisingly, no additional reduction was seen in vessels treated with HO-1-EPCs relative to GFP-EPCs. Thrombosis occurred in approximately 50% of the saline-treated vessels but was virtually absent in all EPC-transplanted vessels.
  
  
  CONCLUSIONS
  We conclude that transplantation of autologous EPCs overexpressing eNOS in injured vessels enhances the vasculoprotective properties of the reconstituted endothelium, leading to inhibition of neointimal hyperplasia. This cell-based gene therapy strategy may be useful in treatment of vascular disease.
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass 02115, USA.
authors.forename: Deling
authors.initials: D
authors.lastname: Kong
authors.forename: Luis G
authors.initials: LG
authors.lastname: Melo
authors.forename: Abeel A
authors.initials: AA
authors.lastname: Mangi
authors.forename: Lunan
authors.initials: L
authors.lastname: Zhang
authors.forename: Marco
authors.initials: M
authors.lastname: Lopez-Ilasaca
authors.forename: Mark A
authors.initials: MA
authors.lastname: Perrella
authors.forename: Chong C
authors.initials: CC
authors.lastname: Liew
authors.forename: Richard E
authors.initials: RE
authors.lastname: Pratt
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Dzau
mesh_terms: D000800:Angioplasty, Balloon; D000818:Animals; D020212:Carotid Artery Injuries / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D017536:Carotid Artery, Common / Q000473:pathology; D002478:Cells, Cultured / Q000201:enzymology / Q000637:transplantation; D018076:DNA, Complementary / Q000235:genetics; D042783:Endothelial Cells / Q000201:enzymology / Q000637:transplantation*; D004730:Endothelium, Vascular / Q000166:cytology; D004790:Enzyme Induction; D017930:Genes, Reporter; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics; D049452:Green Fluorescent Proteins; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D051547:Heme Oxygenase-1; D006801:Humans; D006965:Hyperplasia; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D008565:Membrane Proteins; D019001:Nitric Oxide Synthase / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D052250:Nitric Oxide Synthase Type III; D012333:RNA, Messenger / Q000096:biosynthesis; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000502:physiology; D012190:Retroviridae / Q000235:genetics; D013927:Thrombosis / Q000209:etiology / Q000517:prevention & control; D014161:Transduction, Genetic; D017539:Tunica Intima / Q000473:pathology*
chemical_list: D018076:DNA, Complementary; D008164:Luminescent Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1