title: Rotational co-culture of clonal β-cells with endothelial cells: effect of PPAR-γ agonism in vitro on insulin and VEGF secretion.
abstract: OBJECTIVE
  Delayed graft revascularization impedes the success of human islet transplantation. This study utilized rotational co-culture of insulin secreting β-cells with human umbilical vein endothelial cells (HUVECs) and a peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist to promote insulin and vascular endothelial growth factor (VEGF) secretory function.
  
  
  METHODS
  Clonal BRIN-BD11 (D11) cells were maintained in static culture (SC) and rotational culture (RC) ± HUVEC and ± the TZD (thiazolidinedione) rosiglitazone (10 mmol/l) as a specific PPAR-γ agonist. HUVECs were cultured in SC and RC ± D11 and ± TZD. D11 insulin secretion was induced by static incubation with low glucose (1.67 mmol/l), high glucose (16.7 mmol/l) and high glucose with 10 mmol/l theophylline (G+T) and assessed by enzyme-linked immunosorbent assay (ELISA). HUVEC proliferation was determined by ATP luminescence, whereas VEGF secretion was quantified by ELISA. Co-cultured cells were characterized by immunostaining for insulin and CD31.
  
  
  RESULTS
  D11 SC and RC showed enhanced insulin secretion in response to 16.7 mmol/l and G+T (p < 0.01); without significant alteration by the TZD. Co-culture with HUVEC in SC and RC also increased D11 insulin secretion when challenged with 16.7 mmol/l and G+T (p < 0.01), and this was slightly enhanced by the TZD. The presence of HUVEC increased D11 SC and RC insulin secretion in response to high glucose and G+T, respectively (p < 0.01). Addition of the TZD increased SC and RC HUVEC ATP content (p < 0.01) and VEGF production (p < 0.01) in the presence and absence of D11 cells.
  
  
  CONCLUSIONS
  Rotational co-culture of insulin secreting cells with endothelial cells, and exposure to a PPAR-γ agonist may improve the prospects for graft revascularization and function after implantation.
authors: Islet Research Laboratory, Worcestershire Clinical Research Unit, Worcestershire Acute Hospitals NHS Trust, Worcester, UK. Michelle.Paget@worcsacute.nhs.uk
authors: M B
authors: MB
authors: Paget
authors: H E
authors: HE
authors: Murray
authors: C J
authors: CJ
authors: Bailey
authors: P R
authors: PR
authors: Flatt
authors: R
authors: R
authors: Downing
mesh_terms: D002460:Cell Line; D018920:Coculture Techniques; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism* / Q000628:therapy; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D016381:Islets of Langerhans Transplantation; D047495:PPAR gamma / Q000819:agonists*; D042442:Vascular Endothelial Growth Factors / Q000378:metabolism*
chemical_list: D007328:Insulin; D047495:PPAR gamma; D042442:Vascular Endothelial Growth Factors