When does reverse cholesterol transport occur?
Reverse cholesterol transport is a term that comprises all the different steps in cholesterol metabolism between cholesterol efflux from macrophage foam cells and the final excretion of cholesterol into the feces either as neutral sterols or after metabolic conversion into bile acids (see Figure 1) [5, 10, 11].
What protein carries out the reverse cholesterol transport?
Reverse Cholesterol Transport (RCT) First, the intestine and liver synthesize the protein Apo A-1 (70% of the protein content of HDL-c), which enters the bloodstream and goes to peripheral tissues (e.g., heart).
How is cholesterol transported into the body?
Cholesterol is transported by complex particles, called lipoproteins, which have specific proteins on their surface. These proteins, called apolipoproteins, have an essential function in the metabolism of lipoproteins.
How is cholesterol transported from liver to peripheral?
LDL are bound and taken up by specific receptors (LDL receptors) in the liver and many other tissues. By this pathway, cholesterol is transported from the liver to peripheral tissues.
What is the role of apo C II and C III?
Apoprotein C-II (ApoC-II) functions as a modulator of the hydrolysis of lipoprotein triglycerides by increasing the activity of lipoprotein lipase. Apoprotein C-III (ApoC-III) appears to have an inhibitory effect on ApoC-II-stimulated hydrolysis.
Which plays the largest role in reverse cholesterol transport?
HDL plays a critical role in reverse cholesterol transport, from peripheral tissues to the liver (Figure 6, Animated). The major lipoprotein components in HDL are ApoAI, ApoCII, and ApoE.
How is cholesterol transported to the liver?
The HDL then transports the cholesterol to the liver either directly by interacting with hepatic SR-B1 or indirectly by transferring the cholesterol to VLDL or LDL, a process facilitated by CETP. Cholesterol efflux from macrophages to HDL plays an important role in protecting from the development of atherosclerosis.
How is cholesterol transported to and from the liver to peripheral tissues?
HDL serves as a chemical shuttle that transports excess cholesterol from peripheral tissues to the liver. This pathway is called the reverse cholesterol transport (RCT) system.
Is the transport of cholesterol from the liver to all tissues?
LDLs are the primary plasma carriers of cholesterol for delivery to all tissues. LDL can be absorbed by the liver and other tissues via receptor mediated endocytosis.