title: Pancreatic duct cells as a source of VEGF in mice.
abstract: OBJECTIVE
  Vascular endothelial growth factor (VEGF) is essential for proper pancreatic development, islet vascularisation and insulin secretion. In the adult pancreas, VEGF is thought to be predominantly secreted by beta cells. Although human duct cells have previously been shown to secrete VEGF at angiogenic levels in culture, an analysis of the kinetics of VEGF synthesis and secretion, as well as elucidation of an in vivo role for this ductal VEGF in affecting islet function and physiology, has been lacking.
  
  
  METHODS
  We analysed purified duct cells independently prepared by flow cytometry, surgical isolation or laser-capture microdissection. We infected duct cells in vivo with Vegf (also known as Vegfa) short hairpin RNA (shRNA) in an intrapancreatic ductal infusion system and examined the effect of VEGF knockdown in duct cells in vitro and in vivo.
  
  
  RESULTS
  Pancreatic duct cells express high levels of Vegf mRNA. Compared with beta cells, duct cells had a much higher ratio of secreted to intracellular VEGF. As a bioassay, formation of tubular structures by human umbilical vein endothelial cells was essentially undetectable when cultured alone and was substantially increased when co-cultured with pancreatic duct cells but significantly reduced when co-cultured with duct cells pretreated with Vegf shRNA. Compared with islets transplanted alone, improved vascularisation and function was detected in the islets co-transplanted with duct cells but not in islets co-transplanted with duct cells pretreated with Vegf shRNA.
  
  
  CONCLUSIONS
  Human islet preparations for transplantation typically contain some contaminating duct cells and our findings suggest that the presence of duct cells in the islet preparation may improve transplantation outcomes.
authors.affiliation: Division of Pediatric Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Ave, Pittsburgh, PA, 15224, USA, xiangwei.xiao@chp.edu.
authors.forename: Xiangwei
authors.initials: X
authors.lastname: Xiao
authors.forename: Krishna
authors.initials: K
authors.lastname: Prasadan
authors.forename: Ping
authors.initials: P
authors.lastname: Guo
authors.forename: Yousef
authors.initials: Y
authors.lastname: El-Gohary
authors.forename: Shane
authors.initials: S
authors.lastname: Fischbach
authors.forename: John
authors.initials: J
authors.lastname: Wiersch
authors.forename: Iljana
authors.initials: I
authors.lastname: Gaffar
authors.forename: Chiyo
authors.initials: C
authors.lastname: Shiota
authors.forename: George K
authors.initials: GK
authors.lastname: Gittes
mesh_terms: D000818:Animals; D004847:Epithelial Cells / Q000166:cytology; D055785:Gene Knockdown Techniques; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D007515:Islets of Langerhans / Q000166:cytology; D016381:Islets of Langerhans Transplantation; D051379:Mice; D018919:Neovascularization, Physiologic; D010183:Pancreatic Ducts / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D055758:SOX9 Transcription Factor / Q000235:genetics; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D034741:RNA, Small Interfering; D055758:SOX9 Transcription Factor; C527933:Sox9 protein, mouse; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse