RESUMO
Type I diabetes mellitus is a metabolic disease caused by the impairment of pancreatic ß-cells mainly mediated through oxidative stress and related apoptosis. Islets transplantation seems a promising treatment for these patients, but during islets transplant, various types of stresses related to the isolation and transplantation procedure compromise the function and viability of islets. We recently hypothesized that the combination of cerium oxide (CeO2) and yttrium oxide (Y2O3) nanoparticles with a potential free radical scavenger behavior should be useful to make isolated islets survive until transplanted. In the present study, oxidative stress-induced apoptosis in isolated rat pancreatic islets exposed to hydrogen peroxide (H2O2) and the protective effects of CeO2 and Y2O3 nanoparticles were investigated. Exposure of islets to H2O2 (50 µm, 2 h) increased intracellular oxidant formation such as reactive oxygen species and subsequently apoptosis and decreased viability, glucose-induced adenosine triphosphate (ATP) production and glucose-stimulated insulin secretion. Pretreatment with CeO2 and/or Y2O3 nanoparticles reduced the oxidant formation and apoptosis and increased viability, glucose-induced ATP production and glucose-stimulated insulin secretion. These results suggest that this combination may protect ß-cell apoptosis by improving the oxidative stress-mediated apoptotic pathway.