The Roles of Hepatic Macrophages in Tissue Homeostasis and Liver Diseases

Macrophages play essential roles in maintaining tissue homeostasis and ensuring a rapid response to liver damage. Dividing hepatic macrophages into heterogeneous subpopulations is conducive to a more comprehensive understanding of their functions. Kupffer cells are self-sustainable microphage populations that reside in the liver and are usually distinguished from monocyte-derived macrophages which only rapidly accumulate in damaged liver. Specific environmental signals determine the further polarization and function of liver macrophages. Various subpopulations of hepatic macrophages can either protect liver integrity after injury or infection or lead to exacerbation of hepatitis, fibrosis and cancer. This article focused on the recent advances in the origin, classification and function of liver macrophages, and discussed their distinct roles in liver physiology and pathology, so as to provide a theoretical basis for further investigation of liver macrophages.