Protection of insulin-secreting INS-1 cells against oxidative stress through adenoviral-mediated glutathione peroxidase overexpression

Diabetes Metab. 2003 Apr;29(2 Pt 1):145-51. doi: 10.1016/s1262-3636(07)70021-6.


Objectives: A large fraction of an islet graft can be lost early following allotransplantation from various non specific mechanisms including oxidative stress. Overexpression of antioxidant enzymes could confer a beneficial effect on islets exposed to reactive oxygen and nitrogen species. We examined the viability of beta cells driven to overexpress glutathione peroxidase (GPx) and exposed to a superoxide donor (hypoxanthine/xanthine oxidase HX/XO) and a nitric oxide donor (3-morpholinosydnonimine SIN-1).

Methods: Cultured INS-1 rat-derived insulin-secreting cells were transfected by an E1-deleted adenovirus carrying GPx cDNA (AdGPx). Additional experiments were performed with an adenovector carrying Cu/Zn superoxide dismutase cDNA (AdSOD). Cellular viability was tested by the WST-1 colorimetric assay and functionality by static incubation.

Results: AdGPx increased GPx activity within 48 hours from 0 (untransfected cells) to 60 +/- 11 U/g (cells transfected at an MOI of 25: 1). GPx overexpression significantly reduced cytotoxicity induced by HX/XO from 10.81 +/- 1.41 to 5.42 +/- 2.62% at 10 mU/ml and from 61.19 +/- 4.17 to 52.9 +/- 4.39% at 20 mU/ml (p=0.0002, transfected cells vs control cells). Doses of SIN-1 from 600 to 1000 micromol/l resulted in cytotoxicity ranging from 17.66 +/- 3.48 to 45.97 +/- 6.48% in control cells and from 5.65 +/- 1.37 to 35.80 +/- 5.59% in AdGPx transfected cells (p=0.015). The combination of AdGPx and AdSOD did not exhibit any synergistic cytoprotective effect. Control cells exposed to a HX/XO stress exhibited a reduction in glucose-theophylline stimulated insulin secretion by half, while stressed GPx overexpressing-cells maintained the same insulin secretion level than non-stressed cells.

Conclusions: Adenoviral-induced overexpression of GPx enhances the resistance of a rat beta cell line to both reactive oxygen (ROS) and reactive nitrogen species (RNS) cytotoxicity. Transposition of these findings to human islet transplantation with a clinically-relevant procedure deserves further investigations.

MeSH terms

  • Adenoviridae
  • Animals
  • Cattle
  • Cell Survival / drug effects*
  • DNA, Complementary / genetics
  • Enzyme Inhibitors / pharmacology
  • Glucose / pharmacology
  • Glutathione Peroxidase / genetics*
  • Glutathione Peroxidase / metabolism
  • Hypoxanthine / pharmacology
  • Insulin / metabolism*
  • Insulin Secretion
  • Insulinoma
  • Molsidomine / analogs & derivatives*
  • Molsidomine / pharmacology
  • Oxidative Stress / physiology*
  • Pancreatic Neoplasms
  • Rats
  • Recombinant Proteins / metabolism
  • Superoxide Dismutase / genetics
  • Superoxide Dismutase / metabolism
  • Transfection
  • Tumor Cells, Cultured
  • Xanthine Oxidase / pharmacology


  • DNA, Complementary
  • Enzyme Inhibitors
  • Insulin
  • Recombinant Proteins
  • Hypoxanthine
  • linsidomine
  • Molsidomine
  • Glutathione Peroxidase
  • Superoxide Dismutase
  • Xanthine Oxidase
  • Glucose