Endothelial lipase
Endothelial Lipase | |
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Identifiers | |
Symbol | LIPG |
Alt. symbols | EL |
Endothelial lipase (LIPG) is a form of
Discovery
In 1999, the identification of endothelial lipase was independently discovered by two research groups.[2]
The first group at Rhone-Poulenc Rorer cloned and characterized a new member of the triacylglyerol (TG) family. When this novel endothelial lipase was over-expressed in mice, the concentrations of HDL Cholesterol and apolipoprotein A-I in plasma decreased.[3]
A second group at Stanford University independently cloned this same endothelial lipase from human umbilical vein endothelial cells, human coronary artery endothelial cells and rodent endothelial-like yolk sacs.[5] Suppression subtractive hybridization was used to isolate the genes.[5] The genes were then compared and aligned. Two cDNA fragments expressed the lipase gene and endothelial properties.[5] Northern blot analysis documented the samples.[5] The suggested relation to metabolism and vascular disease was attributed to tissue selective expression in endothelial cells.[5]
Structure
Endothelial lipase is a protein that belongs triglyceride lipase category.[1] This protein is encoded by the LIPG gene.[1] Endothelial lipase is secreted from vascular endothelial cells, being the only lipase to date.[3] The primary secretion is that of a 55kDa protein which is secreted to a 68kDa protein after post-translational Glycosylation.[1] LIPG functions as it binds to Proteoglycans.[1] LIPG also has the potential for additional cleavage.[1] The additional cleavage would result in inactivity of the 40 kDa protein N-terminal 40 kDa and 28 kDa C-terminal.[1] LIPG has the capability to form a protein dimer prior to secretion which causes dimerization to appear.[1] The addition reaction of the same compound and molecules enhances the resistance to cleavage and limited activity is sustained.[1]
Biological Function
Metabolism
The site of endothelial lipase enzymatic activity is the surface of endothelial cells. LIPG regulates lipoprotein metabolism through the hydrolysis of HDL phospholipids.
Vascular Biology
Endothelial lipase is linked to potential treatment and improvement of atherosclerosis. Atherosclerosis is a vascular disease which is caused by arterial plaque buildup.[8] Cholesterol, fat, calcium, and other components contribute to the formation of plaque in the blood.[8] Plaque is detrimental to vascular heath because it narrows and stiffens the arteries, causing a lack of oxygen-rich blood flow.[8] HDL increase serves as a treatment for atherosclerosis. The hydrolysis of HDL leads to the transportation of cholesterol to the liver.[7] The filtration system of the liver aids in the removal of cholesterol from the body. Therefore, the cholesterol level in the plasma will decrease. Thus, endothelial lipase synthesis of HDL could provide an adequate opportunity to increase HDL levels. Data suggests that endothelial lipase inhibition should increase the plasma HDL, primarily in patients with low HDL-C levels.[4] An increased risk of atherosclerosis is associated with low levels of HDL.[4] Although a functional correlation can be drawn, there is little clinical evidence to provide support to the suggested potential benefits in vascular pathophysiology.
References
- ^ PMID 28540715.
- ^ PMID 16498510.
- ^ S2CID 20658953.
- ^ PMID 21062953.
- ^ PMID 10318835.
- ^ OCLC 1003278428.
- ^ a b c CDC (2017-10-31). "LDL and HDL Cholesterol: "Bad" and "Good" Cholesterol". Centers for Disease Control and Prevention. Retrieved 2019-04-11.
- ^ a b c "Atherosclerosis | National Heart, Lung, and Blood Institute (NHLBI)". www.nhlbi.nih.gov. Retrieved 2019-04-11.
External links
- endothelial+lipase,+human at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
Cell biology |
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