Effects of AT1 receptor autoantibody on renal cell apoptosis and JNK expression in diabetic nephropathy rats

AIM:To study the effects of angiotensin Ⅱ type 1 receptor autoantibody (AT1-AA) on the apoptosis of renal cell and the expression of c-Jun N-terminal kinase (JNK) in diabetic nephropathy (DN) rats. METHODS:High-sucrose and high-fat diet and intraperitoneal injection of streptozotocin were utilized to induce DN rat model. We employed enzyme-linked immunosorbent assay (ELISA) for serum AT1-AA and TUNEL staining for renal cell apoptosis. Furthermore, Western blotting was performed to measure the levels of endoplasmic reticulum stress (ERS) chaperone glucose-regulated protein 78 (GRP78) and ERS-associated apoptosis protein p-JNK. RESULTS:The renal cell apoptotic rate in DN group was significantly increased compared with NC group, and the apoptotic renal cells in AT1-AA positive DN rats were much greater than those in AT1-AA negative DN rats (P<0.05). The protein levels of GRP78 and p-JNK were significantly increased compared with NC group. GRP78 and p-JNK protein levels also significantly increased in AT1-AA positive DN rats compared with AT1-AA negative DN rats. CONCLUSION: AT1-AA activates ERS response and induces renal cell apoptosis via the JNK apoptotic pathway in the renal tissues of DN rats.