Lipoproteins

Deficiency in the orphan G protein-coupled receptor 146 (GPR146) decreases blood lipid levels and protects against atherosclerosis in mice independently of LDL receptor activity, according to a new study.

The entry of remnants of cholesterol-rich lipoproteins, such as low-density lipoprotein (LDL), from the blood stream into the intima of large arteries initiates and then perpetuates atherosclerosis. A study published in Nature sheds new light on this important process by identifying scavenger receptor BI (SR-BI) as a major receptor that mediates LDL delivery across the endothelium into arteries.

The scavenger receptor class B member 1 (SRB1) in endothelial cells mediates active transcellular transport of circulating LDL into the artery wall and thereby drives the accumulation of LDL in macrophages, which become foam cells and promote the development of atherosclerosis

LDL cholesterol is an important contributor to the risk of coronary heart disease, and its measurement is central to evaluating the effects of lipid-modifying therapies. Several ‘LDL-cholesterol’ assays exist but their methodologies differ, leading to between-assay heterogeneity in values of ‘LDL cholesterol’. We advocate the need for awareness of the potential implications.