Activation of farnesoid X receptor attenuates hepatic injury in a murine model of alcoholic liver disease.

Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients.

Excessive bile acid activated NF-kappa B and promoted the development of alcoholic steatohepatitis in farnesoid X receptor deficient mice.

Chronic and excessive alcohol consumption can lead to alcoholic liver disease (ALD), which is characterized by a spectrum of liver disorders, including fatty liver, alcoholic steatohepatitis (ASH), fibrosis/cirrhosis and hepatocellular carcinoma (HCC). The mechanism of the progression from alcoholic steatosis to steatohepatitis and fibrosis is still not fully understood. As a nuclear receptor, farnesoid X receptor (FXR) plays a critical role in maintaining hepatic lipid and bile acid homeostasis. To clarify the role of FXR in the progression of steatohepatitis, we studied the effect of ethanol feeding on FXR-deficient mice. Wild-type and FXR-deficient mice were fed with Lieber-DeCarli ethanol liquid diet or an isocaloric control diet. We found that FXR-deficient mice fed with ethanol diet developed more severe liver injury and steatosis, even progressed to steatohepatitis and moderate fibrosis. Whereas, wild-type (WT) mice only developed mild level of steatosis, with rarely observed inflammatory foci and collagen accumulation. We also found that ethanol induced hepatic bile acid accumulation and NF-κB activation in FXR-deficient mice, which could be attenuated by ursodeoxycholic acid (UDCA). Thus, FXR deficient mice were more prone to develop alcoholic steatohepatitis and fibrosis upon ethanol diet feeding. Our results highlight the role of FXR in hepatoprotection during ALD development. Moreover, attenuating alcoholic liver cholestasis would be beneficial in preventing the progression of hepatic hepatitis in patients with ALD.