high-density lipoprotein particle clearance

Definition

Target type: biologicalprocess

The process in which a high-density lipoprotein particle is removed from the blood via receptor-mediated endocytosis and its constituent parts degraded. [GOC:BHF, GOC:mah]

High-density lipoprotein (HDL) particle clearance is a complex and essential process in maintaining lipid homeostasis and preventing atherosclerosis. HDL particles, known as "good cholesterol," play a crucial role in reverse cholesterol transport, removing excess cholesterol from peripheral tissues and delivering it to the liver for excretion. The clearance of HDL particles involves a series of steps that begin with their interaction with specific receptors on the surface of liver cells. These receptors, primarily the scavenger receptor class B type I (SR-BI) and the ATP-binding cassette transporter A1 (ABCA1), mediate the selective uptake of cholesterol esters from HDL particles without internalizing the entire particle. SR-BI facilitates the direct transfer of cholesterol esters from HDL to the liver cell, while ABCA1 promotes the efflux of free cholesterol from peripheral cells to HDL, ultimately leading to the formation of cholesterol-rich HDL. Once HDL particles have delivered their cholesterol, they can be internalized by hepatocytes through various pathways, including endocytosis mediated by the LDL receptor (LDLR) and other receptors. The internalized HDL particles are then degraded in lysosomes, releasing their components for recycling or excretion. The efficiency of HDL clearance is influenced by factors such as the size and composition of HDL particles, the expression levels of specific receptors, and the activity of enzymes involved in cholesterol metabolism. Dysregulation of HDL clearance can lead to increased levels of cholesterol in the blood, contributing to the development of atherosclerosis and cardiovascular disease.'
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Proteins (2)

Compounds (2)