Calcium dobesilate prevents changes in tight junction proteins in the retina induced by diabetes

Abstract

Purpose Calcium dobesilate has been found to correct the excessive vascular permeability associated with diabetes in the retina of diabetic patients and in experimental diabetes. However, the molecular mechanisms underlying these effects are not elucidated yet. In this study, we investigated the potential protective effect of calcium dobesilate against changes in tight junction proteins (occludin, ZO-1 and claudin-5) induced by diabetes in the retina. Methods Diabetes was induced by an intraperitoneal injection of streptozotocin (65 mg/kg) in two months old male Wistar rats (1 month diabetes duration). The animals were divided in three groups (7-8 animals/group): control, diabetic, diabetic treated with calcium dobesilate (100 mg/kg/day; orally given) during the last 10 days of diabetes. The protein levels and distribution of the tight junction proteins were evaluated by western blotting and immunohistochemistry, respectively. Results Diabetes decreased occludin and claudin-5 protein levels (65.2 ± 7.6% and 63.2 ± 5.4% of the control, respectively) in the retina. ZO-1 levels were unchanged, but its distribution in retinal vessels was altered in the retinal vessels of diabetic animals. The treatment with calcium dobesilate prevented the changes in tight junction proteins induced by diabetes. Conclusion In conclusion, calcium dobesilate is able to prevent changes in tight junction proteins in retinal vessels induced by diabetes, which may explain its beneficial effects against diabetes-induced blood-retinal barrier breakdown. Support: OM PHARMA, Switzerland