Question

How would you modulate the reverse cholesterol transport pathway to increase cholesterol ef?ux from cells in normal individuals?

Answer 1

Cholesterol efflux is a pathway by which intracellular cholesterol from cells is transferred to extracellular acceptors such as apolipoprotein A-1 of high- density- lipoprotein . [HDL]. It occurs during the reverse cholesterol transport pathway. It is very important because accumulated cholesterol is transported from the vessel wall to the liver for excretion, thus preventing atherosclerosis.

Besides HDL and lipoprotein A-1, enzymes such as lecithin: cholesterol acyltransferase [LCAT ] , phospholipid transfer protein [PLTP] , hepatic lipase [HL] and cholesterol ester transfer protein [ CETP ] play an important role in RCT pathway.

Cholesterol efflux Iis facilitated by ATP - binding membrane cassette transporter A1 [ABCA1] or other mechanisms like passive diffusion, scavenger receptor B1, caveolins and sterol 27- hydroxylase and collected by HDL and apoA-1, which deliver them to the liver for excretion. In people with impaired ABCA1 genes , cholesterol efflux is not at proper rate leading to atherosclerosis.. The efflux of cholesterol can be increased by supplementation with HDL or apoA-1.

So, RCT pathway can be modulated to increase cholesterol efflux by supplementing with HDL and apoA-1.