Inhibition of Reactive Gliosis in the Retina of Rats with Streptozotocin-Induced Diabetes under the Action of Hydrated C60 Fullerene

Reactive gliosis induced by metabolic disturbances and development of oxidative stress in the retina at diabetes mellitus is the key pathogenetic factor for the development of diabetic retinopathy. Fullerene C60 and some of its water-soluble derivates are known as rather potent antioxidants displaying neuroprotective capacities during the development of a number of pathologies and harmful influences on the organism. In our study, effects of nanostructures of hydrated C60 fullerene (C60HyFn) on the content and polypeptide composition of glial fibrillary acidic protein (GFAP) in the rat retina under conditions of streptozotocin (STZ)-induced diabetes were evaluated for the first time. Using immunoblotting, strong (more than twofold) up-regulation of GFAP expression in the diabetic rat retina, as compared with the control, was shown (P < 0.01). This was a result of activation of retinal glial cells induced by hyperglycemia. Increased GFAP immunolabeling that was indicative of reactive gliosis in the retina of diabetic rats was also confirmed immunohystochemically. Consumption of C60HyFn solution (60 nM) in drinking water by diabetic rats for 12 weeks caused a significant decrease in the GFAP level in comparison with that in untreated diabetic animals (P < 0.05). In addition, C60HyFn caused statistically significant lowering of the glycated hemoglobin concentration in blood serum of STZ-diabetic rats (P < 0.05). However, it exerted no effects on the insulin and glucose levels in blood of diabetic rats. Our results demonstrated that hydrated C60 fullerene as a potential high-efficacy retinoprotective agent within the initial period of diabetic retinopathy; it significantly suppresses activation of retinal macroglia.