M2b macrophages protect against doxorubicin induced cardiotoxicity via alternating autophagy in cardiomyocytes

Objective: Doxorubicin (DOX) is an anthracycline Antibiotic which is widely used for the treatment of various cancers, while the dose-related cardiotoxicity limits its potential therapeutic application. The underlying mechanism of DOX induced cardiotoxicity is complex and remains elusive. Our previous studies have shown that M2b macrophage plays an important role in reducing inflammation due to ischemic reperfusion injury in the myocardium. The purpose of this study was to investigate the potential protective role of M2b macrophages in DOX induced cardiotoxicity.

Methods: In vivo, we conducted DOX induced cardiac injury in C57BL/6 mice and treated them with M2b macrophages. Then, the mice were examined by echocardiography. The heart specimens were harvested for histological examination, transmission electron microscope analysis, and Autophagy molecules evaluation. In vitro, HL-1 cardiac cell lines treated with DOX were cocultured with or without M2b macrophages. Then, Autophagy related genes and protein expression were assessed by real-time quantitative PCR and western blot; cell proliferation was assessed by cell counting kit-8.

Results: We found that M2b macrophages can improve cardiac function and alleviate cardiac injury in DOX induced cardiac injury mice. M2b macrophages can enhance cardiac Autophagy levels both in vivo and in vitro in DOX induced cardiac injury model. In addition, this protective effect can be blocked by an Autophagy Inhibitor.

Conclusion: Our study shows that M2b macrophages can help attenuate the DOX induced cardiotoxicity by regulating the Autophagy level of cardiomyocytes.