Dual Role of Pregnane X Receptor in Nonalcoholic Fatty Liver Disease.

The incidence of nonalcoholic fatty liver disease (NAFLD) has been rising worldwide in parallel with diabetes and metabolic syndrome. NAFLD refers to a spectrum of liver abnormalities with a variable course, ranging from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), eventually leading to cirrhosis and hepatocellular carcinoma. Pregnane X receptor (PXR), a member of the nuclear receptor superfamily, plays a prominent part in the regulation of endogenous metabolic genes in NAFLD. Recent studies have suggested that PXR has therapeutic potential for NAFLD, yet the relationship between PXR and NAFLD remains controversial. In this review, PXR is proposed to play a dual role in the development and progression of NAFLD. Its activation will aggravate steatosis of the liver, reduce inflammatory response, and prevent liver fibrosis. In addition, the interactions between PXR, substance metabolism, inflammation, fibrosis, and gut microbiota in non-alcoholic fatty liver were elucidated. Due to limited therapeutic options, a better understanding of the contribution of PXR to the pathogenesis of NAFLD should facilitate the design of innovative drugs targeting NAFLD.