Transport of LDLs into the arterial wall: impact in atherosclerosis

Atherosclerosis is a complicated cardiovascular disease characterized by unbalanced lipid metabolism and unresolved inflammation that occurred inside of arteries. The transcytosis of LDL across the endothelium and its accumulation in the arterial wall is the initial step of atherosclerosis. Here, we summarize recent research into the understanding of the regulatory mechanisms of endothelial LDL transcytosis and its relevance in the development of atherosclerosis.

A number of recent studies have revealed the contribution of caveolae, activin-like kinase 1 (ALK1) or scavenger receptor B1 (SR-B1) in endothelial LDL transcytosis and the progression of atherosclerosis. Caveolin-1 (Cav-1), the major protein component in caveolae, is required for the formation of caveolae and caveolae-mediated LDL uptake and transcytosis across the endothelium. SR-B1 and ALK1 directly bind LDL and facilitate the transport of LDL through the endothelial cells. The change in expression of caveolae-associated proteins and SR-B1 regulates endothelial LDL transcytosis and the pathogenesis of atherosclerosis.

Caveolae, ALK1 and SR-B1 are identified as key regulators in the LDL transcytosis across the endothelium. Endothelial LDL transcytosis might be a potential therapeutic approach to limit the initiation of early atherosclerosis and treat the atherosclerotic vascular diseases.