Issue Archive

Changes of bone morphogenetic protein--7 and inhibitory Smad expression in streptozotocin--induced diabetic nephropathy rat kidney

Yang Qin, Han Bing, Xie Rujia, Cheng Mingliang

Department of Pathophysiology, Guiyang medical university.Guiyang 550004,Guizhou

Abstract

The present study was designed to observe the expressions of bone morphogenetic protein-7 (BMP-7) and inhibitory Smads in kidney of rats with diabetic nephropathy (DN), and explore the possible mechanism of DN. Male Wistar rats weighing 180-220 g were single injected with streptozocin (STZ, 55 mg/kg body weight) for 2, 4, 8 and 16 weeks to induce DN. Blood glucose, kidney weight/body weight and 24-hour urine protein in the control and DN rats were examined; the expressions of BMP-7, Smad6 and Smad7 were detected by using immunohistochemical techniques, western blot and real-time PCR. The results showed that blood glucose and 24-hour urine protein in DN rats were higher than that in the control rats and kidney weight/body weight was also elevated in DN rats, especially in 16-week STZ-induced rats. The expressions of BMP-7 and Smad6 proteins in DN rats were elevated, while BMP-7 mRNA expression was increased 2 weeks after STZ injection and decreased 16 weeks after STZ injection. The expressions of Smad7 protein and mRNA were elevated in DN rats 2 weeks after STZ injection and decreased 16 weeks after STZ injection. In addition, the expression of transforming growth factor-#beta#1(TGF-#beta#1) and collagen type I(COL-I) mRNA were increased in DN rats. These results suggested in the early stage of DN, increase in BMP-7 and inhibitory Smads expression may play a role in the feedback regulation and restrain the development of DN.

Key words: diabetic nephropathy;bone morphogenetic protein-7;Smad6;Smad7;transforming growth factor-#beta#;streptozotocin

Received: 　　Accepted:

Corresponding author: 　　E-mail:

Citing This Article：

Yang Qin, Han Bing, Xie Rujia, Cheng Mingliang. Changes of bone morphogenetic protein--7 and inhibitory Smad expression in streptozotocin--induced diabetic nephropathy rat kidney. Acta Physiol Sin 2007; 59 (2): 190-196 (in Chinese with English abstract).