Self-maintenance of Cardiac Resident Reparative Macrophages Attenuates Doxorubicin-induced Cardiomyopathy through the SR-A1-c-Myc Axis

ABSTRACT: Rationale: Doxorubicin-induced cardiomyopathy (DiCM) is a significant cause of heart failure and mortality in cancer patients, in which macrophage-orchestrated inflammation serves as an essential pathogenic mechanism. However, the specific roles of tissue-resident and monocyte-derived macrophages in DiCM remain poorly understood. Objective: Uncovering the origins, phenotypes, and functions of proliferative cardiac resident macrophages and mechanistic insights into the self-maintenance of cardiac macrophage during DiCM progression. Methods and Results: Mice were administrated with doxorubicin to induce cardiomyopathy. Dynamic changes of resident and monocyte-derived macrophages were examined by lineage tracing, parabiosis, and bone marrow transplantation. We found that the monocyte-derived macrophages primarily exhibited a pro-inflammatory phenotype that dominated the whole DiCM pathological process and impaired cardiac function. In contrast, cardiac resident macrophages were vulnerable to doxorubicin insult. The survived resident macrophages exhibited enhanced proliferation and conferred a reparative role. Global or myeloid specifically ablation of class A1 scavenger receptor (SR-A1) inhibited proliferation of cardiac resident reparative macrophages and therefore exacerbated cardiomyopathy in DiCM mice. Importantly, the detrimental effect of macrophage SR-A1 deficiency was confirmed by transplantation of GFP+ wild type bone marrow. At the mechanistic level, we show that c-Myc, a key transcriptional factor for the SR-A1-P38-SIRT1 pathway, mediated the effect of SR-A1 in reparative macrophage proliferation in DiCM. Conclusions: The SR-A1-c-Myc axis may represent a promising target to treat DiCM through augmentation of cardiac resident reparative macrophage proliferation.

ORGANISM(S): Mus musculus

PROVIDER: GSE147834 | GEO | 2023/03/31

REPOSITORIES: GEO