title: A comparison of the pro-angiogenic potential of human induced pluripotent stem cell derived endothelial cells and induced endothelial cells in a murine model of peripheral arterial disease.
abstract: BACKGROUND
  Endothelial cells derived from human induced pluripotent stem cells (iPSC-ECs) promote angiogenesis, and more recently induced endothelial cells (iECs) have been generated via fibroblast trans-differentiation. These cell types have potential as treatments for peripheral arterial disease (PAD). However, it is unknown whether different reprogramming methods produce cells that are equivalent in terms of their pro-angiogenic capabilities.
  
  
  OBJECTIVE
  We aimed to directly compare iPSC-ECs and iECs in an animal model of PAD, in order to identify which cell type, if any, displays superior therapeutic potential.
  
  
  METHODS
  IPSC-ECs and iECs were generated from human fibroblasts, and transduced with a reporter construct encoding GFP and firefly luciferase for bioluminescence imaging (BLI). Endothelial phenotype was confirmed using in vitro assays. NOD-SCID mice underwent hindlimb ischaemia surgery and received an intramuscular injection of either 1×106iPSC-ECs, 1×106iECs or control vehicle only. Perfusion recovery was measured by laser Doppler. Hindlimb muscle samples were taken for histological analyses.
  
  
  RESULTS
  Perfusion recovery was enhanced in iPSC-EC treated mice on day 14 (Control vs. iPSC-EC; 0.35±0.04 vs. 0.54±0.08, p<0.05) and in iEC treated mice on days 7 (Control vs. iEC; 0.23±0.02 vs. 0.44±0.06, p<0.05), 10 (0.31±0.04 vs. 0.64±0.07, p<0.001) and 14 (0.35±0.04 vs. 0.68±0.07, p<0.001) post-treatment. IEC-treated mice also had greater capillary density in the ischaemic gastrocnemius muscle (Control vs. iEC; 125±10 vs. 179±11 capillaries/image; p<0.05). BLI detected iPSC-EC and iEC presence in vivo for two weeks post-treatment.
  
  
  CONCLUSIONS
  IPSC-ECs and iECs exhibit similar, but not identical, endothelial functionality and both cell types enhance perfusion recovery after hindlimb ischaemia.
authors.affiliation: Heart Research Institute, 7 Eliza Street, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Camperdown, NSW 2006, Australia. Electronic address: Zoe.Clayton@hri.org.au.
authors.forename: Zoe E
authors.initials: ZE
authors.lastname: Clayton
authors.affiliation: Heart Research Institute, 7 Eliza Street, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Camperdown, NSW 2006, Australia. Electronic address: Gloria.Yuen@hri.org.au.
authors.forename: Gloria S C
authors.initials: GS
authors.lastname: Yuen
authors.affiliation: Heart Research Institute, 7 Eliza Street, Newtown, NSW 2042, Australia. Electronic address: sara.sadeghipour81@gmail.com.
authors.forename: Sara
authors.initials: S
authors.lastname: Sadeghipour
authors.affiliation: Heart Research Institute, 7 Eliza Street, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Camperdown, NSW 2006, Australia. Electronic address: Jack.Hywood@hri.org.au.
authors.forename: Jack D
authors.initials: JD
authors.lastname: Hywood
authors.affiliation: Department of Cardiovascular Sciences, Houston Methodist Research Institute, 6670 Bertner Ave, Houston, TX 77030, USA. Electronic address: wwong@houstonmethodist.org.
authors.forename: Jack W T
authors.initials: JW
authors.lastname: Wong
authors.affiliation: Department of Cardiothoracic Surgery, Stanford University, Stanford, CA. Stanford Cardiovascular Institute, Stanford, CA, United States. Electronic address: ngantina@stanford.edu.
authors.forename: Ngan F
authors.initials: NF
authors.lastname: Huang
authors.affiliation: Heart Research Institute, 7 Eliza Street, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Camperdown, NSW 2006, Australia; Department of Cardiology, Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW 2050, Australia. Electronic address: Martin.Ng@hri.org.au.
authors.forename: Martin K C
authors.initials: MK
authors.lastname: Ng
authors.affiliation: Department of Cardiovascular Sciences, Houston Methodist Research Institute, 6670 Bertner Ave, Houston, TX 77030, USA. Electronic address: jpcooke@houstonmethodist.org.
authors.forename: John P
authors.initials: JP
authors.lastname: Cooke
authors.affiliation: Heart Research Institute, 7 Eliza Street, Newtown, NSW 2042, Australia; Sydney Medical School, University of Sydney, Camperdown, NSW 2006, Australia; Department of Cardiology, Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW 2050, Australia. Electronic address: Sanjay.Patel@hri.org.au.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Patel
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D065150:Cellular Reprogramming / Q000502:physiology; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000502:physiology*; D005347:Fibroblasts / Q000502:physiology; D006614:Hindlimb / Q000098:blood supply; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000502:physiology; D007511:Ischemia / Q000378:metabolism / Q000628:therapy; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D055414:Myocardial Perfusion Imaging / Q000379:methods; D058729:Peripheral Arterial Disease / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy; D033581:Stem Cell Transplantation / Q000379:methods*; D016896:Treatment Outcome
keywords: Angiogenesis; Cell therapy; Differentiation; Endothelial cells; Peripheral arterial disease; Reprogramming