ASBT

Apical sodium-dependent bile acid transporter (ASBT, SLC10A2) is a key membrane transporter encoded by the SLC10A2 gene. It is primarily expressed on the apical membrane of terminal ileal epithelial cells and is responsible for the active reabsorption of bile acids. It utilises the sodium ion gradient to transport bile acids back to the liver from the intestinal lumen at a 2:1 coupling ratio, thereby maintaining the homeostasis of bile acids and cholesterol in the body. ASBT preferentially binds conjugated bile acids such as glycocholic acid and taurocholate. Its expression is regulated by multiple factors, including transcription factors and nuclear receptors. ASBT dysfunction or genetic mutations can disrupt bile acid metabolism, leading to disorders such as hypercholesterolaemia and primary bile acid malabsorption syndrome.