Cholesterol absorption pathway

The **cholesterol absorption pathway** refers to the multistep biological process by which dietary and biliary cholesterol is absorbed from the intestinal lumen into enterocytes and subsequently transported into circulation. The key molecular mediator is **Niemann-Pick C1-like 1 protein (NPC1L1)**, a transmembrane transporter highly expressed on the brush border membrane of small intestinal epithelial cells. Free cholesterol from micelles interacts with NPC1L1 for uptake into enterocytes. Once inside, it is esterified by acyl-CoA:cholesterol acyltransferase (ACAT), packaged with triglycerides and apolipoprotein B48 into chylomicrons via microsomal triglyceride transfer protein (MTP), then secreted into lymphatics for systemic distribution. Efflux back to the gut lumen is mediated by ATP-binding cassette transporters ABCG5/ABCG8[2][4][6][8]. This process regulates whole-body cholesterol homeostasis and plays a central role in cardiovascular risk; pharmacologic inhibition of this pathway—most notably by ezetimibe—reduces plasma LDL-cholesterol levels. "Cholesterol absorption pathway" describes a **biological process**, not a single molecule or receptor. The actual therapeutic targets within this pathway are specific proteins such as **NPC1L1** or ABCG5/ABCG8; thus, listing "Cholesterol absorption pathway" as a target is incorrect—it should be replaced with one or more precise molecular entities like "Niemann-Pick C1-like 1 protein"[2][4][6][8].

Other names

Intestinal cholesterol absorptionCholesterol uptake pathwayNPC1L1-mediated cholesterol transportEnterocyte cholesterol transport

Inhibition of intestinal cholesterol transporter NPC1L1 to reduce dietary and biliary cholesterol absorption