Vol. 6, Issue 1, Part A (2024)

Background: The hepatobiliary system is essential in the synthesis and secretion of bile, a process that involves the intricate coordination of several hepatobiliary transporters. These transporters play a critical role in the assembly and secretion of biliary lipids, including bile acids, cholesterol, and phospholipids, which are vital for digestive function and lipid homeostasis. The precise mechanisms by which hepatobiliary transporters facilitate the assembly of these lipids into bile remain a subject of significant research interest.
Objective: This paper aims to explore the role of key hepatobiliary transporters in the assembly and secretion of biliary lipids, with a focus on the molecular mechanisms that drive native bile formation.
Methods: A comprehensive review of the current literature was conducted, focusing on studies that investigated the function of hepatobiliary transporters in bile formation. Key transporters such as BSEP (Bile Salt Export Pump), MDR3 (Multidrug Resistance Protein 3), and ABCG5/ABCG8 were analyzed for their roles in lipid transport and their implications in bile composition.
Results: The assembly of biliary lipids is a highly coordinated process involving the hepatobiliary transporters BSEP, MDR3, and ABCG5/ABCG8. BSEP mediates the secretion of bile acids into the bile canaliculi, which in turn facilitates the solubilization of cholesterol and phospholipids. MDR3 is essential for the translocation of phosphatidylcholine into bile, while ABCG5/ABCG8 regulate the secretion of cholesterol. Deficiencies in these transporters lead to disrupted bile formation and have been linked to diseases such as cholestasis and gallstone disease.
Conclusion: Hepatobiliary transporters play a crucial role in the assembly of biliary lipids and the formation of native bile. Understanding their molecular mechanisms provides insights into disorders associated with bile formation and highlights potential therapeutic targets for treating hepatobiliary diseases.