Expression and significance of NF-κB in retina of rats with diabetes mellitus

Objective To investigate the expression of nuclear factor-kappa B (NF-κB) in retina of rats with diabetes mellitus and its effects on pathogenesis of diabetic retinopathy(DR).Methods A total of 110 clearing healthy adult male Wistar rats were randomly divided into normal control group (NC group,24 rats) and diabetic model group (DM group,86 rats).Intraperitoneal injection of streptozotocin (STZ) was taken to induce diabetic models.A total of 72 phragmoid rats were randomly divided into 2 weeks group,4 weeks group,12 weeks group and 20 weeks group,18 rats in each group.At each forementioned time,6 rats in DM group and 2 rats in NC group were sacrificed.NF-κB protein expression in retina of rats with different courses of diabetes mellitus were observed by immunoblotting method.NF-κB expression in retinal tissues and vessels of rats with different courses of diabetes mellitus were observed by immunohistochemical method.Results The protein level of NF-κB p65 was very weak about 17.72±8.57 in normal rats of NC group.In 2 weeks after modeling,the protein level of NF-κB p65 in DM group was 38.45±12.37.The expression of NF-κB p65 increased continually with prolonging of time,and reached to peak about 89.41±19.79 at 4 weeks after modeling with immunoblotting reaction,the protein level at each time point was significantly higher than that of NC group(all P0.01).There were positive staining granules of NF-κB on the retinal vascular surface at 2 weeks after modeling;There were some positive staining cells of NF-κB in the inner nuclear layer and its vessels at 4 weeks after modeling;There were a large number of positive staining cells of NF-κB in vessels at retinal surface,inner nuclear layer and its vessels,outer plexiform layer at 12 weeks after modeling.No expression of NF-κB was found in normal rat retinal vessels.There were scattered positive staining granules of NF-κB on the retinal vessel wall at 2 weeks after modeling,gradually increased with prolonging of time,reached to peak at 12 weeks and remained stable at following time.Conclusion NF-κB plays an important role in the progress of DR.