Death receptor 5 agonists mitigate cardiac pathology in a chronic isoproterenol-induced cardiac remodeling and dysfunction.

Heart failure is a leading cause of death. Despite the economic and health burden, few recent therapeutic advances have been made and current therapies alleviate the symptoms, but minimally impact mortality, highlighting the need for identifying novel therapeutic targets. Death receptor 5 (DR5) has been studied extensively in cancer for its role in inducing apoptosis in transformed cells. However, DR5 is ubiquitously expressed, including in the heart, where its function is poorly understood. Clinical studies have associated DR5 and its ligand, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), with heart failure due to multiple etiologies. Previous studies in cardiac cells and mouse models have demonstrated that DR5 promotes eccentric cardiac hypertrophy through ERK1/2-dependent mechanisms and the apoptosis of myofibroblasts. ERK1/2 signaling has been associated with prosurvival mechanisms in cardiomyocytes suggesting DR5 agonism may be a novel therapeutic approach to outcomes in heart failure. We hypothesized that activation of DR5 will be protective in heart failure. Using a chronic isoproterenol administration model, mice were administered a DR5 agonist and progression of cardiac dysfunction was monitored by echocardiography. Cardiac remodeling was assessed by histology and prohypertrophic and profibrotic marker expression. Specificity of these responses was confirmed with DR5 knockout and the involvement of ERK1/2 signaling was confirmed using pharmacological inhibitors. DR5 agonists decreased cardiac remodeling and improved contractility in response to isoproterenol, which was prevented by ERK1/2 inhibition. These findings demonstrate that activation of DR5 reduces the progression of cardiac remodeling and dysfunction and may be a novel therapeutic target for heart failure treatment. SIGNIFICANCE STATEMENT: Death receptor 5 (DR5) is expressed in cardiomyocytes where its function is poorly defined and clinically, DR5 has been associated with heart failure development and severity. Previous studies show in healthy cardiomyocytes, DR5 activates ERK1/2 signaling, causing eccentric hypertrophy, which are associated with cardioprotection during heart failure. This study investigates the therapeutic potential of targeting DR5 and demonstrates that, in a chronic isoproterenol-infusion model of cardiac dysfunction, DR5 activation reduces maladaptive cardiac remodeling and preserves function through ERK1/2-dependent mechanisms.