The Expression Of Endoplasmic Reticulum Stress-related Factor Hrd1 In Retina Of Diabetic Rats

Objective Endoplasmic reticulum stress(ER stress) is involving in the onset and the progression of diabetic retinopathy. And Hrd1 play a key role in stabilizing internal environment of endoplasmic reticulum and inhibiting the endoplasmic reticulum stress via the ER stress-association degradation pathway. We detected the change of ER stresss-related factors with gene array, and analysis the role of Hrd1 in retina of diabetic rats via observing the expression in retina of diabetic rats and human retinal capillary endothelial cells (HRCECs) cultured in high-glucose medium.Methods Diabetic models of SD rats were induced by intraperitioneal injection of 65mg/kg streptozotocin(STZ). Control rats were injected with an equal dose of citrate sodium vehicle. Blood glucose level was measured with rat-tail blood colection method at the time of 72h. After 7days,only the rats with blood glucose levels≥16.77mmol/L were identified typeⅠdiabetic rat model. And momitored the blood level with the method weekly until harvested the retinas of rats at the time of 3 month. The gene expression changes of eithty-nine ER stress-related factors were tested by RT-RNA PCR Arrays. Observed the expression change of Hrd1 protein in retina of diabetic group and control group with Western blot and immunofluorescence methods . In vitro studies, HRCECs were cultured in the high-glucose medium for 48h, and the protein expression of Hrd1 was assessed by immunofluorescence methods.Results In the retinal tissue : PCR arrays showed that in the eighty-nine gens, the mRNA expression of twelve factors had change, and the expression of Hrd1 decreased in the 3m diabetic group(P<0.05). Significantly decrease of the protein expression level of Hrd1was observed with Western blot, compared with the control group (P <0.05). Immunofluoresce- nce showed tha the green fluorescence of Hrd1 protein witch marked by FITC became darker, meaning the expression of Hrd1 declined in the retina and (P <0.05). For the cells cultured in high-glucose medium, immunofluorescence also showed that the protein expression of Hrd1 significantly declined (P <0.05).Conclusion These results suggest that the twelve factors whitch had change are involved in the onset and the progression of diabetic retinopathy. And Hrd1 paly an importain role in reponse to ER stress in diabetic retinopathy.