Apelin-13 protects against myocardial infarction-induced myocardial fibrosis

Myocardial infarction is a serious health threat. Apelin is an endogenous ligand of angiotensin II receptor-like 1 (APJ) and the apelin/APJ system is associated with various types of heart disease. However, whether apelin protects against myocardial infarction‑induced myocardial fibrosis remains unclear. The present study aimed to investigate the function of apelin‑13 during myocardial infarction‑induced myocardial fibrosis, and to determine the mechanism underlying the effects of apelin‑13. Apelin‑13 was demonstrated to improve left ventricular function and results of hematoxylin and eosin staining, Masson's trichrome staining and western blotting showed that apelin‑13 attenuated myocardial fibrosis. Further mechanistic investigation was performed by enzyme‑linked immunosorbent assay, western blotting and electrophoretic mobility shift assay. The results demonstrated that apelin‑13 inhibited the activation of nuclear factor (NF)‑κB signaling in vitro and in vivo. To the best of our knowledge, the present study was the first to demonstrate that apelin‑13 may attenuate myocardial infarction‑induced myocardial fibrosis, and that this protective function may be mediated by inhibition of NF‑κB signaling. The present study suggests a theoretical basis for the effects of apelin‑13 and provides insight into the potential clinical application of apelin-13.