Which lipoprotein is central to reverse cholesterol transport from peripheral tissues back to the liver?

Which lipoprotein is central to reverse cholesterol transport from peripheral tissues back to the liver?

• A. LDL
• B. VLDL
• C. High-density lipoprotein
• D. Chylomicrons

Answer: (C)

Reverse cholesterol transport is the process by which excess cholesterol is moved from peripheral tissues back to the liver for elimination. The lipoprotein central to this pathway is HDL. It starts when cholesterol is effluxed from macrophages and other peripheral cells to lipid-poor ApoA-I, forming nascent HDL. As HDL circulates, LCAT esterifies free cholesterol on its surface, creating a cholesterol ester–rich core and maturing the particle. This allows HDL to shuttle cholesterol from tissues to the liver, where it is taken up by hepatocytes via SR-BI and disposed of into bile (directly or after conversion to bile acids). While CETP can exchange cholesteryl esters between HDL and other lipoproteins, the crucial feature is HDL’s role in collecting cholesterol from tissues and delivering it for excretion. Other lipoproteins mainly transport cholesterol to tissues or carry dietary lipids, rather than serving as the primary vehicles for removing tissue cholesterol.

Reverse cholesterol transport is the process by which excess cholesterol is moved from peripheral tissues back to the liver for elimination. The lipoprotein central to this pathway is HDL. It starts when cholesterol is effluxed from macrophages and other peripheral cells to lipid-poor ApoA-I, forming nascent HDL. As HDL circulates, LCAT esterifies free cholesterol on its surface, creating a cholesterol ester–rich core and maturing the particle. This allows HDL to shuttle cholesterol from tissues to the liver, where it is taken up by hepatocytes via SR-BI and disposed of into bile (directly or after conversion to bile acids). While CETP can exchange cholesteryl esters between HDL and other lipoproteins, the crucial feature is HDL’s role in collecting cholesterol from tissues and delivering it for excretion. Other lipoproteins mainly transport cholesterol to tissues or carry dietary lipids, rather than serving as the primary vehicles for removing tissue cholesterol.