Aryl hydrocarbon receptor attenuates cholestatic liver injury by regulating bile acid metabolism

Cholestatic liver disease is defined as the bile acids (BAs) accumulation in the liver caused by impaired synthesis, and secretion, together with excretion of BAs due to a variety of factors, which, if left untreated, can result in hepatic fibrosis, cholestatic cholangitis, cholestatic cirrhosis, eventually, end-stage liver disease. Currently, modulation of BA metabolism is still a prospective therapeutic strategy for treating the cholestatic diseases. Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor with far-reaching effects on the chronic liver disease. However, its role and mechanism in cholestatic liver damage is still unknown. Therefore, in this work, we explored the impact of AHR on the cholestatic liver injury using AHR overexpression mediated by adeno-associated viral (AAV) vectors. We found that AHR is differentially expressed in different stages of cholestatic liver disease, showing either down-regulation or an increase in protective effects. Overexpression of AHR increased body weight, decreased serum total bilirubin (TBil) and alkaline phosphatase (ALP), reduced porphyrin accumulation in liver tissue, and regulated the bile acid pool in the cholestatic mouse model induced by DDC diet. Overall, our data indicate that AHR attenuated cholestatic liver injury. AHR function indicates that it may have an action in the clinical management of cholestasis.