Intestinal uptake of dietary cholesterol.

<p>Dietary cholesterol (ch) and plant sterols/stanols (ps) travel, incorporated in mixed micelles, through the intestinal lumen. The sterols are transported across the brush-border membrane by NPC1L1. Once taken up, sterols are either incorporated in apoB48-rich chylomicrons (CM), which are secreted in the lymph compartment, or used to form apoA1-rich HDL cholesterol, a process that is mediated by ABCA1. Excess amounts of sterols are also excreted into the intestinal lumen by the reverse sterol transporters ABCG5 and G8. The level of transport proteins is under tight control of the liver X receptor (LXR) gene. This gene indirectly measures cellular sterol levels and regulates the transcription of sterol transporters NPC1L1, ABCA1, ABCG5 and G8.