Interleukin‐38 alleviates cardiac remodelling after myocardial infarction

Excessive immune-mediated inflammatory reaction plays a deleterious role in ventricular remodelling after myocardial infarction (MI). Interleukin (IL)-38 is a newly characterized cytokine of the IL-1 family and has been reported to exert a protective effect in some autoimmune diseases. However, its role in cardiac remodelling post-MI remains unknown. In this study, we found that the expression of IL-38 was increased in infarcted heart after MI induced in C57BL/6 mice by permanent ligation of the left anterior descending artery. In addition, our data showed that ventricular remodelling after MI was significantly ameliorated after recombinant IL-38 injection in mice. This amelioration was demonstrated by better cardiac function, restricted inflammatory response, attenuated myocardial injury and decreased myocardial fibrosis. Our results in vitro revealed that IL-38 affects the phenotype of dendritic cells (DCs) and IL-38 plus troponin I (TNI)-treated tolerogenic DCs dampened adaptive immune response when co-cultured with CD4+ T cells. In conclusion, IL-38 plays a protective effect in ventricular remodelling post-MI, one possibility by influencing DCs to attenuate inflammatory response. Therefore, targeting IL-38 may hold a new therapeutic potential in treating MI.