Cell type-specific contribution of low-density lipoprotein receptor to atherosclerosis

Elevated blood low-density lipoprotein (LDL) levels are a major risk factor for cardiovascular disease. Increasing LDL receptor (LDLR) expression effectively reduces blood LDL and serves as a key therapeutic strategy for preventing and treating cardiovascular disease. However, it remains unclear how LDLR in different aortic cells contributes to atherosclerosis progression. In this study, we found that hepatocyte-specific deletion of Ldlr in combination with high-fat, high-cholesterol diet feeding induced hypercholesterolemia and atherosclerosis in mice. On this background, further deletion of Ldlr in endothelial cells or smooth muscle cells had no significant effects on atherosclerosis, whereas myeloid-selective ablation of Ldlr markedly attenuated atherosclerotic plaque formation. The decreased percentages of T cells and natural killer T cells in the aorta of mice lacking Ldlr in myeloid cells partially explained the reduced atherosclerotic burden, despite that bone marrow-derived macrophages from Ldlr knockout mice could still be induced to form foam cells in vitro. Therefore, LDLR is better to be elevated in a cell-specific manner for cardiovascular disease prevention and treatment.