The Expression Of ER-associated Degradation Related Factors In The Retina Of Diabetic Rats

Objective:The quality of the proteins folded in the ER is carefully monitored by an ER quality control mechanism that misfolded or unassembled proteins to be retained in the ER and subsequently degraded in a process termed ER-associated degradation (ERAD). ERAD maintain steady-state levels of cell and to avoide ER stress. Diabetic retinopathy (DR) is closely related to ER stress. This study sought to explore the expression of ERAD related factors in diabetic retinopathy(DR), and analyze the function of ERAD related factors in DR.Method: In vivo studies, rat diabetic models were induced by intraperitoneal injection of streptozotocin (STZ), and the rats injected with equal quantity phosphate-buffered saline were used as nondiabetic controls. Expression of ERAD related factors in retina in groups of rat diabetic models at 1 month was assessed by Real-time Arrays. The expression of protein for Herp was assessed by Western blotting and immunofluorescence staining. In vitro studies, human retinal capillary endothelial cells (HRCECs) were cultured in the 25mM glucose concentrations, and the expression of protein for Herp was assessed by immunofluorescence staining.Result: 13 genes of ER stress related factors's mRNA expression were changed in diabetic rats compared to control rats at 1 moth.These genes distributed in 8 classes ER stress related factors. The expression of ERAD related factors including Herp, NUC, Os9, ADO15 mRNA were changed in diabetic rats compared to control rats at 1 moth (P<0.05). The expression of protein for Herp was significantly decreased in diabetic rats compared to control rats at 1 month evaluated by western blot and immunofluorescence staining(P<0.05). In RRCECs cultured 25mM glucose concentrations , the green fluorescent was significantly reduced, herp expression was decreased(P<0.05).Conclusion: Expression of ERAD related factor significantly decreased in diabetic rats at 1 months compared to control . ERAD participated in the occurrence and development of diabetic retinopathy at the early stage.