The G-Protein Coupled Receptor P2Y2 is Upregulated in the Diabetic Rat Retina. Possible Role in Diabetic Retinopathy.

GALLO, JE; MANCINI, JE; ORTIZ, G; CROXATTO, JO

ORLANDO

Congreso; ARVO ANNUAL MEETING; 2014

ASSOCIATION FOR RESEARCH IN VISION AND OPHTHALMOLOGY

Purpose:Purinergic P2Y2r have been reported to be involved in inflammation and to have a neuroprotective effect. We aimed at evaluating the role of P2Y2r in experimental diabetic retinopathy Methods: Three groups of 5 male Wistar rats with a weight of 250g were treated with an intraperitoneal injection of 45mg/kg of streptozotocin. Animals with glycemia levels above 200 mg/dl were included in the study. A control group was made up of 5 non-diabetic rats. PPADS and suramin, purinergic antagonists, were twice intraperitoneally injected to a group of diabetic animals each, at 9 and 24 weeks of diabetes. Animals were sacrificed at 28 weeks of diabetes. Retinas were analyzed by immunohistochemistry and western blot using primary antibodies against P2Y2r, GFAP, VEGF-A and Caspase-3. Results: P2Y2r immunoreactivity was found in the fiber layer of non-diabetic and diabetic animals. These animals also showed immunostaining of P2Y2r at the photoreceptor outer segment. Western-blot confirmed the higher expression of P2Y2r in diabetics than controls. Diabetic animals treated with PPADS showed a higher protein expression of P2Y2r than those without treatment. Besides, PPADS and Suramin diabetic groups had higher protein expressions of VEGF-A and Caspase-3 than that found in diabetic animals without therapy. Conclusions: P2Y2r seems to be involved in inflammatory and apoptotic mechanisms in experimental diabetic retinopathy. Results suggest that P2Y2r might have a protective effect in the diabetic rat retina