Contradictory regulation of macrophages on atherosclerosis based on polarization, death and autophagy

The main pathological feature of atherosclerosis is lipid metabolism disorder and inflammation. Macrophages, as the most important immune cells in the body, run through the beginning and end of disease development. After macrophages overtake the atherosclerosis-susceptible area apolipoprotein low-density lipoprotein ox-LDL, they transform into foam cells that adhere to blood vessels and recruit a large number of pro-inflammatory factors to initiate the disease. Promoting the outflow of lipids in foam cells and alleviating inflammation have become the basic ideas for the study of atherosclerosis treatment strategies. The polarization of macrophages refers to the estimation of the activation of macrophages at a specific point in space and time. Determining the proportion of different macrophage phenotypes in the plaque can help identify delay or prevent disease development. However, the abnormal polarization of macrophages and the accumulation of lipid also affect the growth state of cells to some extent, thus aggravate the influence on plaque area and stability. Besides, overactive or deficient autophagy of macrophages may also lead to cell death and participate in lipid metabolism and inflammation regression. In this paper, the role of macrophages in atherosclerosis was discussed from three aspects: polarization, death, and autophagy.