title: Xenografted human amniotic fluid-derived stem cell as a cell source in therapeutic angiogenesis.
abstract: BACKGROUND
  Amniotic fluid-derived stem cells (AFSCs) are pluripotent with high renewal capacity and are not tumorigenic. We tested whether AFSCs can function as a cell source for therapeutic angiogenesis in a mouse hindlimb ischemia model.
  
  
  METHODS
  Using a defined culture medium for endothelial lineage cells (ECs), we differentiated human AFSCs into AFSC-derived ECs (AFSC-ECs) in vitro, as evidenced by expression of EC markers, and capillary-like network formation on Matrigel. We assessed the in vivo therapeutic angiogenesis efficacy of AFSC-ECs in an athymic nude mouse model of hindlimb ischemia. One day after high ligation of the external iliac artery in athymic nude mice, AFSC-ECs were intramuscularly injected into ischemic limbs.
  
  
  RESULTS
  The AFSC-ECs demonstrated endothelial cell characteristics in vitro. Four weeks later, AFSC-ECs transplantation significantly increased limb salvage (85%), compared to AFSCs (56%), human umbilical vein endothelial cells (HUVECs; 25%), or medium (0%). Laser Doppler perfusion analysis revealed that the ischemic/normal limb blood perfusion ratio significantly improved in the AFSC-EC group. AFSC-EC transplantation significantly increased capillary and arteriole densities as compared to AFSCs, HUVECs, and medium. Transplanted AFSC-ECs were incorporated into vessels in the ischemic region, as confirmed by immunofluorescent staining for human smooth muscle 22α or von Willebrand factor. Matrix metalloproteinase (MMP)-3 and MMP-9 expressions were significantly higher in AFSC-ECs. MMP-9 might activate angiogenesis by regulation of vascular endothelial growth factor.
  
  
  CONCLUSIONS
  Our study indicated that AFSC-EC transplantation improved limb salvage and blood perfusion by promoting neovascularization. Therefore, AFSC-ECs possess the potential for therapeutic angiogenesis.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, National Cheng Kung University College of Medicine and Hospital, Tainan 704, Taiwan.
authors.forename: Yen-Wen
authors.initials: YW
authors.lastname: Liu
authors.forename: Jun-Neng
authors.initials: JN
authors.lastname: Roan
authors.forename: Saprina P H
authors.initials: SP
authors.lastname: Wang
authors.forename: Shiaw-Min
authors.initials: SM
authors.lastname: Hwang
authors.forename: Ming-Song
authors.initials: MS
authors.lastname: Tsai
authors.forename: Jyh-Hong
authors.initials: JH
authors.lastname: Chen
authors.forename: Patrick C H
authors.initials: PC
authors.lastname: Hsieh
mesh_terms: D000653:Amniotic Fluid / Q000166:cytology* / Q000502:physiology*; D000818:Animals; D019070:Cell Lineage / Q000502:physiology*; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000502:physiology* / Q000637:transplantation; D005260:Female; D061307:Human Umbilical Vein Endothelial Cells / Q000502:physiology / Q000637:transplantation; D006801:Humans; D007511:Ischemia / Q000473:pathology / Q000601:surgery; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D018919:Neovascularization, Physiologic / Q000502:physiology*; D014183:Transplantation, Heterologous / Q000379:methods*