Lipoprotein Lipase: A General Review

Carbohydrates (e.g., glucose) and lipids (e.g., free fatty acids or FFAs) are the most important sources of energy for most organisms, including humans. Lipoprotein lipase (LPL) is an extracellular enzyme (EC 3.1.1.34) that is essential in lipoprotein metabolism. LPL is a glycoprotein that is synthesized and secreted in several tissues (e.g., adipose tissue, skeletal muscle, cardiac muscle, and macrophages). At the luminal surface of the vascular endothelium (site of the enzyme action), LPL hydrolyzes triglyceride-rich lipoproteins (e.g., chylomicrons, very lowdensity lipoproteins), providing FFAs and glycerol for tissue use. Therefore, LPL plays a key metabolic role in providing substrates for lipogenesis and lipid storage, and in supplying immediate energy for different tissues. Knowledge about this enzyme has greatly increased over the past decade. A detailed understanding of the fascinating, although complex, apparatus by which LPL exerts its catalytic activity in the turbulent bloodstream is just one of the examples. Additionally, interest in LPL activity has been reinforced by its pathophysiological relevance in chronic degenerative diseases such as dyslipidemia, obesity, type 2 diabetes mellitus, and Alzheimer's disease, and in other contexts of disordered lipid metabolism such as severe hypertriglyceridemia and the (potentially) associated acute pancreatitis as well as in non-alcoholic fatty liver disease. This work aimed at critically reviewing the current knowledge of historical, terminological, biochemical, pathophysiological, and therapeutic aspects of human LPL activity.