Cardiac macrophage CD163 protects pressure overload-induced heart failure via interleukin-10

Cardiac macrophages (cMacs) elimination exacerbates pressure overload-induced heart failure. However, the role of functionally distinct subsets of cMacs in heart failure remains largely unknown. CD163, a macrophage-specific scavenger receptor expressed in a subset of cMacs, has been associated with cardiovascular events through its circulating soluble form. This study aimed to elucidate the functional role of the CD163+ cMacs subset in pressure overload-induced heart failure. Transverse aortic constriction (TAC) was used to induce pressure overload. TAC-induced left ventricular systolic dysfunction, characterized by reduced ejection fraction and fractional shortening, was significantly aggravated in Cd163−/− mice post-surgery. Genes differentially expressed due to CD163 deficiency were enriched in pathways related to mitochondrial bioenergetics and homeostasis. Transmission electron microscopy revealed an increase in dysfunctional mitochondria in cardiomyocytes of Cd163−/− mice post-TAC. Additionally, decreased serum interleukin (IL)-10 levels and reduced IL-10 expression in cMacs were observed in Cd163−/− mice post-TAC. IL-10 supplementation significantly reversed TAC-induced reductions in left ventricular systolic function in Cd163−/− mice and improved mitochondrial functions in cardiomyocytes. Furthermore, decreased IL-10 levels and increased soluble CD163 were identified as risk factors for heart failure in hypertensive patients. Thus, CD163 in cMacs attenuates pressure overload-induced left ventricular systolic dysfunction through IL-10.