Related Experiment Video
Updated: Jul 15, 2026
Antagonistic Effect of Jiawei Shengjiang San on a Rat Model of Diabetic Nephropathy: Related to EGFR/MAPK3/1 Signaling Pathway
Published on: May 10, 2024
[Changes of bone morphogenetic protein-7 and inhibitory Smad expression in streptozotocin-induced diabetic
Qin Yang1, Bing Han, Ru-Jia Xie
1Department of Pathophysiology, Guiyang Medical College, Guiyang, China. qinyang@gmc.edu.cn
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 expressions of transforming growth factor-beta1 (TGF-beta1) and collagen type I (COL-I) mRNA were increased in DN rats. These results suggest in the early stage of DN, increase in BMP-7 and inhibitory Smad expression may play a role in the feedback regulation and restrain the development of DN.
Insights
In diabetic nephropathy (DN) rats, elevated bone morphogenetic protein-7 (BMP-7) and inhibitory Smad expression in early stages may help regulate and limit kidney damage.
Area of Science:
- Nephrology
- Molecular Biology
- Endocrinology
Context:
- Diabetic nephropathy (DN) is a significant complication of diabetes mellitus.
- Understanding the molecular mechanisms underlying DN is crucial for developing effective treatments.
Purpose:
- To investigate the expression of bone morphogenetic protein-7 (BMP-7) and inhibitory Smads (Smad6, Smad7) in the kidneys of rats with streptozotocin (STZ)-induced DN.
- To explore the potential role of these molecules in the pathogenesis and progression of DN.
Summary:
- STZ-induced DN in rats showed increased blood glucose, kidney weight, and urinary protein.
- Early-stage DN exhibited elevated protein and mRNA expression of BMP-7 and inhibitory Smads (Smad6, Smad7).
- Transforming growth factor-beta1 (TGF-beta1) and collagen type I (COL-I) mRNA levels were also increased in DN rats.
Impact:
- The findings suggest that increased BMP-7 and inhibitory Smad expression in the early phase of DN may act as a protective feedback mechanism.
- This regulatory response could potentially restrain the progression of kidney damage in diabetic nephropathy.
