(Pro)renin receptor-mediated myocardial injury, apoptosis, and inflammatory response in rats with diabetic cardiomyopathy

Excessive activation of the renin-angiotensin system (RAS) in diabetic cardiomyopathy (DCM) provokes a series of structural and functional abnormalities, and causes ventricular remodeling and heart failure in diabetes. (Pro)renin receptor (PRR) is a component of the RAS and has been reported to be up-regulated in some cardiovascular diseases. Furthermore, PRR blockade in some cardiovascular diseases, such as myocardial infarction and hypertension, has been demonstrated to reverse their pathogenesis. However, there have been few studies about the function of PRR in the pathogenesis of DCM. In this study, we hypothesized that PRR is involved in the pathogenesis of DCM and mediates myocardial injury in DCM. To explore the role of PRR in DCM, we evaluated the effects of PRR overexpression and knockdown on the DCM phenotype in vivo and in vitro. The results show that PRR overexpression exacerbates myocardial injury and the inflammatory response in rats with DCM. Conversely, PRR knockdown alleviates myocardial fibrosis, apoptosis, and the inflammatory response, reversing the cardiac dysfunction in rats with DCM. In cell experiments, PRR overexpression also up-regulated the protein expression of collagen I and fibronectin, aggravated the inflammatory response, and increased the production of reactive oxygen species (ROS), while PRR knockdown had the opposite effect. Thus, PRR mediates myocardial injury, apoptosis, and the inflammatory response, likely through a PRR/extracellular signal-regulated kinase/ROS pathway.