title: Donor islet endothelial cells in pancreatic islet revascularization.
abstract: OBJECTIVE
  Freshly isolated pancreatic islets contain, in contrast to cultured islets, intraislet endothelial cells (ECs), which can contribute to the formation of functional blood vessels after transplantation. We have characterized how donor islet endothelial cells (DIECs) may contribute to the revascularization rate, vascular density, and endocrine graft function after transplantation of freshly isolated and cultured islets.
  
  
  METHODS
  Freshly isolated and cultured islets were transplanted under the kidney capsule and into the anterior chamber of the eye. Intravital laser scanning microscopy was used to monitor the revascularization process and DIECs in intact grafts. The grafts' metabolic function was examined by reversal of diabetes, and the ultrastructural morphology by transmission electron microscopy.
  
  
  RESULTS
  DIECs significantly contributed to the vasculature of fresh islet grafts, assessed up to 5 months after transplantation, but were hardly detected in cultured islet grafts. Early participation of DIECs in the revascularization process correlated with a higher revascularization rate of freshly isolated islets compared with cultured islets. However, after complete revascularization, the vascular density was similar in the two groups, and host ECs gained morphological features resembling the endogenous islet vasculature. Surprisingly, grafts originating from cultured islets reversed diabetes more rapidly than those originating from fresh islets.
  
  
  CONCLUSIONS
  In summary, DIECs contributed to the revascularization of fresh, but not cultured, islets by participating in early processes of vessel formation and persisting in the vasculature over long periods of time. However, the DIECs did not increase the vascular density or improve the endocrine function of the grafts.
authors.affiliation: The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Nyqvist
authors.forename: Stephan
authors.initials: S
authors.lastname: Speier
authors.forename: Rayner
authors.initials: R
authors.lastname: Rodriguez-Diaz
authors.forename: R Damaris
authors.initials: RD
authors.lastname: Molano
authors.forename: Sasa
authors.initials: S
authors.lastname: Lipovsek
authors.forename: Marjan
authors.initials: M
authors.lastname: Rupnik
authors.forename: Andrea
authors.initials: A
authors.lastname: Dicker
authors.forename: Erwin
authors.initials: E
authors.lastname: Ilegems
authors.forename: Elsie
authors.initials: E
authors.lastname: Zahr-Akrawi
authors.forename: Judith
authors.initials: J
authors.lastname: Molina
authors.forename: Maite
authors.initials: M
authors.lastname: Lopez-Cabeza
authors.forename: Susana
authors.initials: S
authors.lastname: Villate
authors.forename: Midhat H
authors.initials: MH
authors.lastname: Abdulreda
authors.forename: Camillo
authors.initials: C
authors.lastname: Ricordi
authors.forename: Alejandro
authors.initials: A
authors.lastname: Caicedo
authors.forename: Antonello
authors.initials: A
authors.lastname: Pileggi
authors.forename: Per-Olof
authors.initials: PO
authors.lastname: Berggren
mesh_terms: D000818:Animals; D000867:Anterior Chamber; D002470:Cell Survival; D042783:Endothelial Cells / Q000502:physiology* / Q000637:transplantation; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007515:Islets of Langerhans / Q000098:blood supply* / Q000648:ultrastructure; D016381:Islets of Langerhans Transplantation; D007668:Kidney; D008562:Membrane Glycoproteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D008822:Mice, Transgenic; D018919:Neovascularization, Physiologic; D017472:Receptors, Interleukin-1; D013997:Time Factors; D016042:Transplantation, Heterotopic
chemical_list: D008562:Membrane Glycoproteins; D017472:Receptors, Interleukin-1; C434984:TIRAP protein, human; D049452:Green Fluorescent Proteins