[Role of macrophages in the pathogenesis of septic cardiomyopathy]

Sepsis is a life-threatening organ dysfunction caused by the body's dysregulated response to infection. Reversible myocardial dysfunction caused by sepsis is known as septic cardiomyopathy. A thorough understanding of the pathogenesis of septic cardiomyopathy is crucial for early intervention to prevent its progression and improve the success rate of sepsis treatment. At present, the research on the pathogenesis of septic cardiomyopathy mainly focuses on two aspects: the systemic neuroimmune mechanism and the local changes of cardiomyocytes. The former mainly includes the autonomic nervous dysfunction mainly caused by sympathetic overactivation and the inflammatory storm induced by immune response disorder. The latter covers the dysregulation of calcium homeostasis, mitochondrial dysfunction and energy metabolism disorder of cardiomyocytes. Immune dysfunction is one of the key factors that cause the poor prognosis of patients with septic cardiomyopathy. Macrophages are sentinel cells of the body's innate immunity. Cardiac macrophages have been confirmed to be one of the most heterogeneous immune cells in the heart. According to their origin and differentiation, they can be divided into bone marrow-derived tissue infiltrating macrophages and cardiac resident macrophages, which have roles of polarization, phagocytosis, regulation of inflammatory response, and participate in innate and adaptive immunity. In the occurrence and development of septic cardiomyopathy, cardiac macrophages recruited from the blood participate in balancing the inflammation and repair of myocardial tissue through the conversion of pro-inflammatory phenotype and anti-inflammatory phenotype. Cardiac resident macrophages mediate immune phagocytosis to maintain the local homeostasis of cardiomyocytes, and the glycometabolic reprogramming of macrophages regulates the release of inflammatory factors, while macrophage metabolic reprogramming regulates the release of inflammatory factors. A deeper understanding of the biological behavior of macrophages, and regulating the polarization, metabolism and phagocytosis of cardiac macrophages, could serve as new target for the prevention and treatment of septic cardiomyopathy. Therefore, this article reviews the key pathogenesis of septic cardiomyopathy and the role of macrophages of different origins and differentiation, revealing the possibility of developing new strategies for the prevention and treatment of septic cardiomyopathy.