Cardiomyocyte-Derived Apelin Rescues Viral Myocarditis-Induced Cardiac Lymphatic Dysfunction and Remodeling.

Recent research has indicated that cardiac lymphatic vessels (CLVs) serve as a direct drainage route into the mediastinal lymph nodes for inflammation resolution. However, the role of CLVs in coxsackievirus B3-induced acute viral myocarditis (AVMC) remains unknown. In this study, we found that AVMC in mice promoted pathological cardiac lymphangiogenesis while impairing CLV-mediated drainage, leading to heart inflammation and dysfunction. Overexpression of apelin in cardiomyocytes improved CLV integrity and promoted effective lymph drainage to decrease inflammatory responses and enhance cardiac function. In vitro studies revealed that apelin stabilizes lymphatic endothelial cadherin and zonula occludens 1 to enhance lymphatic function via the AKT signaling pathway. Moreover, pre-existing lymphatic defects induced by blocking vascular endothelial growth factor receptor 3 partially diminished the benefits of cardiomyocyte-derived apelin overexpression in AVMC. Taken together, these data indicate that functional CLVs restored by cardiomyocyte-derived apelin facilitate inflammation resolution and improve heart dysfunction in AVMC. Thus, CLV-based therapeutic strategies may serve as a novel approach for alleviating AVMC heart damage.