title: Development of a one-step embryonic stem cell-based assay for the screening of sprouting angiogenesis.
abstract: BACKGROUND
  Angiogenesis assays are important tools for the identification of regulatory molecules and the potential development of therapeutic strategies to modulate neovascularization. Although numerous in vitro angiogenesis models have been developed in the past, they exhibit limitations since they do not recapitulate the entire angiogenic process or correspond to multi-step procedures that are not easy to use. Convenient, reliable, easily quantifiable and physiologically relevant assays are still needed for pharmacological screenings of angiogenesis.
  
  
  RESULTS
  Here, we have optimized an angiogenesis model based on ES cell differentiation for screening experiments. We have established conditions leading to angiogenic sprouting of embryoid bodies during ES cell differentiation in type I three-dimensional collagen gels. Immunostaining experiments carried out during these cultures showed the formation of numerous buds comprising CD31 positive cells, after 11 days of culture of ES cells. Moreover, this one-step model has been validated in response to activators and inhibitors of angiogenesis. Sprouting was specifically stimulated in the presence of VEGF and FGF2. Alternatively, endothelial sprouting induced by angiogenic activators was inhibited by angiogenesis inhibitors such as angiostatin, TGFbeta and PF4. Sprouting angiogenesis can be easily quantified by image analysis after immunostaining of endothelial cells with CD31 pan-endothelial marker.
  
  
  CONCLUSIONS
  Taken together, these data clearly validate that this one-step ES differentiation model constitutes a simple and versatile angiogenesis system that should facilitate, in future investigations, the screening of both activators and inhibitors of angiogenesis.
authors: Inserm, U882, Grenoble, F-38054 France. hermantbastien@hotmail.com <hermantbastien@hotmail.com>
authors: Bastien
authors: B
authors: Hermant
authors: Agnès
authors: A
authors: Desroches-Castan
authors: Marie-Laure
authors: ML
authors: Dubessay
authors: Marie-Hélène
authors: MH
authors: Prandini
authors: Philippe
authors: P
authors: Huber
authors: Daniel
authors: D
authors: Vittet
mesh_terms: D043925:Angiogenesis Inducing Agents / Q000008:administration & dosage*; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage*; D000818:Animals; D001681:Biological Assay / Q000379:methods; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D018919:Neovascularization, Physiologic / Q000187:drug effects* / Q000502:physiology; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects* / Q000502:physiology
chemical_list: D043925:Angiogenesis Inducing Agents; D020533:Angiogenesis Inhibitors