Research progress on the role of bile salts in ischemic-type biliary lesion after liver transplantation / 器官移植

Ischemic-type biliary lesion (ITBL) refers to biliary tract injury caused by insufficient blood supply of hepatic artery, which is one of the main factors affecting the long-term survival and quality of life of liver transplant recipients. The incidence of ITBL is associated with cold and warm ischemia, acute and chronic rejection, cytomegalovirus infection and the bile effect, etc. The occurrence of ITBL is a complicated process involving with multiple factors and steps. The therapeutic option of ITBL is extremely limited. A large proportion of ITBL patients should undergo repeated liver transplantation. ITBL has become one of the most critical factors preventing further advancement of liver transplantation. Hence, it is of significance to strengthen prevention and explore more effective modalities. Recent studies have found that toxic injury of bile salts plays a central role in ITBL. Active regulation of bile components, regulation of bile acid-related receptor expression and blockage or activation of bile acid-related signaling pathways probably have potentials in the prevention and treatment of ITBL. In this article, the cytotoxicity of bile salts and the mechanism of bicarbonate umbrella in the incidence and progression of ITBL after liver transplantation were reviewed, aiming to provide reference for the diagnosis and treatment of ITBL.

Bile acid signaling and biliary functions

This review focuses on various components of bile acid signaling in relation to cholangiocytes. Their roles as targets for potential therapies for cholangiopathies are also explored. While many factors are involved in these complex signaling pathways, this review emphasizes the roles of transmembrane G protein coupled receptor (TGR5), farnesoid X receptor (FXR), ursodeoxycholic acid (UDCA) and the bicarbonate umbrella. Following a general background on cholangiocytes and bile acids, we will expand the review and include sections that are most recently known (within 5-7 years) regarding the field of bile acid signaling and cholangiocyte function. These findings all demonstrate that bile acids influence biliary functions which can, in turn, regulate the cholangiocyte response during pathological events.