RELATION BETWEEN ALDOSE REDUCTASE ENZYME AND THE SIGNAL PATHWAY OF PROTEIN KINASE C IN THE IN VITRO DIABETIC RETINOPATHY MODEL

Abstract

Diabetic retinopathy is an important microangiopathy which effects the pre‐capillary arterioles, capillaries and venules of retina. More than 90 % of all diabetic patients have retinopathy within which causes serious health problems. Several molecular mechanisms have been described to explain the retinal, neural and vascular disorders caused by diabetes. Formation of advanced glycation products, oxidative stress, hexosamine pathway, PKC pathway and polyol pathways are among of these mechanisms. Although it has been known that the PKC signaling pathway and the aldose reductase related polyol pathway are interacting with each other, it is not clearly known whether inhibition or activation of aldose reductase in human retinal cells effects the PKC level and activity, cell proliferation and apoptosis under hyperglycemia and oxidative conditions. In this study, the interaction between AR and PKC in ARPE‐19 cells have been investigated. The relationship between oxidative stress, PKC and AR is very important for the development of diabetic complications such as retinopathy. Our studies have shown that these three mechanisms are closely related to each other. In this context, the AR enzyme can be considered as tissue dependent and its inhibition for the benefit/harm of the cell must be evaluated carefully. In conclusion, AR and PKC pathways are closely related to each other in in‐vitro diabetic retinopathy model. The relation between AR and PKC signaling pathways under hyperglycemia and oxidative stress conditions plays an important role in the control of various cellular pathways.