A Study On The Significance Of NF-κB And PDGF-B Expression In The Retina Of Diabetic Rats

Obective To investigate the change of the activity of nuclear factor-κB (NF-κB) and the expression of platelet-derived growth factor-B (PDGF-B) ,as well as their relationship with diabetic retinopathy(DR),then evaluate their effect on the development of DR.Methods 60 SD rats were divided into two groups, the normal control group and diabetic group. Diabetes was induced in SD rats by streptozotocin (STZ) intraperitoneal injection in diabetic group. Retinal paraffin sections were stained by immunohistochemical (SP) method to investigate the changes of the activity of NF-κB and the expression of PDGF-B at the first month,the third month and the sixth month of diabetes duration.Results 1,Early in the third month, vacuolation was presented in the retinal ganglion cells, and the pathologic changes were aggravated with the development of diabetes. 2,Immunohistochemistry demonstrated that in diabetic retina, NF-κB was activated and predominantly expressed in the nuclear of the retinal ganglion cells,vascular endothelial cells,the inner and the outer nuclear layer cells only after one month of diabetes duration. While in the normal control group, NF-κB was expressed slightly in the cytoplasm of the retinal ganglion cells. In the same duration, the levels of NF-κB in diabetic retina were significantly higher than those in normal controls. Moreover, the activity of NF-κB was enhanced gradually with the duration.3,In diabetic retina, the expression of PDGF-B was enhanced greatly in the first month of diabetes duration, which was presented in the retinal ganglion cells, vascular endothelial cells and the photoreceptor cells. While in the normal control group, the expression of PDGF-B was located at the retinal ganglion cells, vascular endothelial cells. The levels of PDGF-B in diabetic retina were significantly increased than those in normal controls with the same duration. Which were strengthened gradually in the course of diabetes.4,There was a obvious positive correlation between NF-κB and PDGF-B.Conclusion1,There appear pathologic change in the rats with 3 monthes of diabetes duration, and duration was a risk factor for the progression of DR.2,NF-κB was activated before any pathologic change appearing in diabetic retina, and it,s activity was enhanced gradually with the duration.3,Before pathologic changes were found, the expression of PDGF-B was already increased significantly in diabetic retina , moreover, this trend was intensified during the course of diabetes.4,NF-κB may regulate the expression of PDGF-B in DR.5,NF-κB and PDGF-B may play an important role in the onset and the development of DR, these results may supply a new way to prevent and delay DR.