Zhanquan Jiao1, Jun Chen1, Yanhong Liu2, Tong Liu1, Kangyin Chen1, Guangping Li1. 1. a Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology , Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University , Tianjin , China and. 2. b Department of Cardiology , Tianjin Third Central Hospital , Tianjin , China.
Abstract
BACKGROUND: The risk of contrast-induced acute kidney injury (CIAKI) is significantly increased in patients with diabetes mellitus. This study aimed to investigate molecular mechanisms of contrast media-induced apoptosis in diabetic rat kidneys, especially the involvement of ERK1/2 and JNK signal pathways. METHODS: Diabetic Sprague-Dawley rats were induced by intraperitoneal injection of streptozotocin. Ten weeks later the normal and diabetic rats were administered high-osmolar contrast media (HOCM; meglumine diatrizoate) or normal saline (10 mL/kg) injection for 2 consecutive days. At 24 h after the operation, the rats were sacrificed, the blood samples were collected for examining serum creatinine and the kidneys were collected for determining the expression of caspase-3 by immunohistochemistry and the expression of Bcl-2, Bax, upstream signal molecule p-JNK, and p-ERK1/2 by western blotting. RESULTS: The serum creatinine was significantly increased in diabetes + contrast media group (DC group) after operation compared with in the diabetic group (D group; 103.89 ± 9.01 μmol/L vs. 71.52 ± 7.03 μmol/L, p < 0.05). While creatinine clearance rate (Ccr) was significantly decreased in DC group after operation (1.49 ± 0.33 mL/min vs. 2.60 ± 0.54 mL/min, p < 0.05). Especially, in the diabetic kidney, the expression of caspase-3 was also significantly increased after intravenous injection of HOCM compared with normal saline. The expression level of upstream signal molecule p-JNK protein was apparently increased, but p-ERK1/2 protein was significantly decreased (both p < 0.05). CONCLUSIONS: The ionic HOCM-induced renal cells apoptosis in diabetic rats through activating the caspase-3 apoptotic pathway, which might be mediated by upstream MAPK (inhibiting p-ERK1/2 expression and promoting p-JNK expression) signal pathways.
BACKGROUND: The risk of contrast-induced acute kidney injury (CIAKI) is significantly increased in patients with diabetes mellitus. This study aimed to investigate molecular mechanisms of contrast media-induced apoptosis in diabeticrat kidneys, especially the involvement of ERK1/2 and JNK signal pathways. METHODS:DiabeticSprague-Dawley rats were induced by intraperitoneal injection of streptozotocin. Ten weeks later the normal and diabeticrats were administered high-osmolar contrast media (HOCM; meglumine diatrizoate) or normal saline (10 mL/kg) injection for 2 consecutive days. At 24 h after the operation, the rats were sacrificed, the blood samples were collected for examining serum creatinine and the kidneys were collected for determining the expression of caspase-3 by immunohistochemistry and the expression of Bcl-2, Bax, upstream signal molecule p-JNK, and p-ERK1/2 by western blotting. RESULTS: The serum creatinine was significantly increased in diabetes + contrast media group (DC group) after operation compared with in the diabetic group (D group; 103.89 ± 9.01 μmol/L vs. 71.52 ± 7.03 μmol/L, p < 0.05). While creatinine clearance rate (Ccr) was significantly decreased in DC group after operation (1.49 ± 0.33 mL/min vs. 2.60 ± 0.54 mL/min, p < 0.05). Especially, in the diabetic kidney, the expression of caspase-3 was also significantly increased after intravenous injection of HOCM compared with normal saline. The expression level of upstream signal molecule p-JNK protein was apparently increased, but p-ERK1/2 protein was significantly decreased (both p < 0.05). CONCLUSIONS: The ionic HOCM-induced renal cells apoptosis in diabeticrats through activating the caspase-3 apoptotic pathway, which might be mediated by upstream MAPK (inhibiting p-ERK1/2 expression and promoting p-JNK expression) signal pathways.