Effects of diabetes and hypoxia on gene markers of angiogenesis (HGF, cMET, uPA and uPAR, TGF-alpha, TGF-beta, bFGF and Vimentin) in cultured and transplanted rat islets

Diabetologia. 2000 Jun;43(6):763-72. doi: 10.1007/s001250051374.


Aims/hypothesis: The vascularisation of newly transplanted islets originates from the recipients. Because islets transplanted into a diabetic do less well than those transplanted into a euglycaemic environment, we examined the hypothesis that gene expression of angiogenic factors in grafts is delayed in diabetes. These factors include hepatocyte growth factor (HGF) and its receptor c-MET, and urokinase plasminogen activator (uPA) and its receptor uPAR, basic fibroblast growth factor (bFGF), TGF-alpha and TGF beta-1.

Methods: Isolated rat islets were studied in vitro under normoxic and hypoxic culture conditions and gene expression was determined with semi-quantitative multiplex RT-PCR. We found that HGF but not c-MET expression was induced by hypoxia in vitro. Using syngeneic Lewis rats, gene expression was also studied in grafts on days 1, 3, 5, 7 and 14 after transplantation.

Results: In grafts of normoglycaemic rats, HGF expression was enhanced on day 3 and maintained whereas expression of c-MET fell and remained down until day 14. Expression of uPA was up at day 3 and remained high; expression of uPAR was also up at day 3 but then fell to control levels at day 14. Expression of bFGF, TGF-alpha and TGF beta-1 persisted throughout. Vimentin, a marker of fibroblasts, had increased expression at day 1 which was further enhanced in subsequent days. In the grafts of diabetic recipients the expression of HGF, uPA and uPAR were delayed, being clearly expressed at day 5 rather than day 3. Vimentin expression was similarly delayed.

Conclusion/interpretation: This apparent delay in angiogenesis provides a potential mechanism for the less favourable outcomes of islets transplanted into diabetic recipients.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cells, Cultured
  • Diabetes Mellitus, Experimental / genetics
  • Diabetes Mellitus, Experimental / physiopathology*
  • Diabetes Mellitus, Experimental / surgery
  • Fibroblast Growth Factor 2 / analysis
  • Fibroblast Growth Factor 2 / genetics*
  • Genetic Markers
  • Hepatocyte Growth Factor / analysis
  • Hepatocyte Growth Factor / genetics*
  • Islets of Langerhans / blood supply*
  • Islets of Langerhans Transplantation / physiology*
  • Male
  • Neovascularization, Physiologic*
  • Proto-Oncogene Proteins c-met / analysis
  • Proto-Oncogene Proteins c-met / genetics
  • Rats
  • Rats, Inbred Lew
  • Rats, Sprague-Dawley
  • Receptors, Cell Surface / analysis
  • Receptors, Cell Surface / genetics
  • Receptors, Urokinase Plasminogen Activator
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transforming Growth Factor alpha / analysis
  • Transforming Growth Factor alpha / genetics*
  • Transforming Growth Factor beta / analysis
  • Transforming Growth Factor beta / genetics*
  • Transplantation, Homologous
  • Urokinase-Type Plasminogen Activator / analysis
  • Urokinase-Type Plasminogen Activator / genetics*
  • Vimentin / analysis
  • Vimentin / genetics


  • Genetic Markers
  • Plaur protein, rat
  • Receptors, Cell Surface
  • Receptors, Urokinase Plasminogen Activator
  • Transforming Growth Factor alpha
  • Transforming Growth Factor beta
  • Vimentin
  • Fibroblast Growth Factor 2
  • Hepatocyte Growth Factor
  • Proto-Oncogene Proteins c-met
  • Urokinase-Type Plasminogen Activator