Neuregulin-1/ErbB signaling is impaired in the rat model of diabetic cardiomyopathy.

BACKGROUND

Diabetic cardiomyopathy (DCP) is one of the leading causes of increased morbidity and mortality in the diabetic population. The neuregulin-1(NRG1)/ErbB signal system plays a critical role in maintenance of adult heart function. But little is known about the changes of NRG1/ErbB signal system in DCP. The aim of this study was to investigate the changes of the NRG1/ErbB signal system in DCP.

METHODS

A rat model of DCP was established using a single intraperitoneal injection of streptozotocin (STZ). Cardiac function was assessed using echocardiography. The left ventricle fibrosis was evaluated using Masson's trichrome staining. The mRNA expression profiles of ErbB2 and ErbB4 receptors were evaluated using real-time polymerase chain reaction. The protein expression of NRG1 and the phosphorylation of ErbB2 and ErbB4 receptors were assessed using Western blot analysis.

RESULTS

The results showed dramatic left ventricle fibrosis and impaired left ventricle systolic function at 12 weeks after STZ-induced diabetes. This study also showed that ErbB2 and ErbB4 mRNA expression and NRG1 protein expression in the left ventricular myocardium were significantly decreased. In addition, we observed decreased phosphorylation of the ErbB2 and ErbB4 receptors at 12 weeks after the induction of diabetes.

CONCLUSIONS

These findings suggest that NRG1/ErbB signaling is impaired in DCP, which may play some roles in the pathogenesis of DCP.