[Effects of oxidative stress on MuRF1 expression in skeletal muscle of diabetic rats].

OBJECTIVE: To determine whether muscle-specific RING finger protein 1 (MuRF1) expression induced by oxidative stress lead to muscle wasting in diabetes rats. METHODS: The diabetes rat model was established by high-carbohydrate, high-fat diet and injection of streptozotocin. The expression of MuRF1 in gastrocnemius was detected by immunohistochemistry and real time PCR. The level of lipid peroxidation, SOD and fiber size of gastrocnemius was also detected. Further more, C2C12 myotubes were cultured with different concentration of H2O2 (0, 0.01, 0.05, 0.10 and 0.20 mmol/L), the level of MuRF1 protein was detected by western blot. RESULTS: Compared with the control group, the diabetes rats showed higher level of thiobarbituric acid reactive substances (TBARS) and MuRF1 mRNA and lower fiber size in gastrocnemius (P < 0.01). The oxidative stress induced by H2O2 (0.05, 0.10 and 0.20 mmol/L) upregulated the expression of MuRF1 (P < 0.01) in C2C12 myotube cells. CONCLUSION: Our results indicated that diabetes modulated the expression of MuRF1 leading to muscle wasting, and the mechanism might be involved with oxidative stress.