Changes in the FXR-cistrome and alterations in bile acid physiology in Wilson disease
Year: 2025
Type: article
Abstract: BACKGROUND: Wilson disease (WD) is an autosomal recessive disorder that results in excessive hepatic copper, causing hepatic steatosis, inflammation, fibrosis, cirrhosis, and liver failure. Previous studies have revealed dysregulation of many farnesoid X receptor (FXR) metabolic target genes in WD, including the bile salt exporter pump, the major determinant of bile flow. METHODS: We tested the hypothesis that the FXR-cistrome is decreased in Atp7b-/- mice in accord with dysregulated bile acid homeostasis. RESULTS: FXR binding within Atp7b-/- mouse livers displayed surprising complexity: FXR binding was increased in distal intergenic regions but decreased in promoter regions in Atp7b-/- versus wild-type mice. Decreased FXR occupancy in Atp7b-/- versus wild-type mice was observed in hepatocyte metabolic and bile acid homeostasis pathways, while enrichment of FXR binding was observed in pathways associated with cellular damage outside of hepatocytes. Indeed, disparate FXR occupancy was identified in parenchymal and non-parenchymal marker genes in a manner that suggests decreased FXR activity in parenchymal cells, as expected, and increased FXR activity in non-parenchymal cells. Consistent with altered FXR function, serum and liver bile acid concentrations were higher in Atp7b-/- mice than in wild-type mice. Comparison of bile acid profiles in the serum of WD patients with "liver," "neurological," or "mixed" disease versus healthy controls also revealed increases in specific bile acids in WD-liver versus healthy controls. CONCLUSIONS: We identified novel FXR-occupancy across the genome that varied in parenchymal and non-parenchymal cells, demonstrating complex FXR regulation of metabolic and hepatocellular stress pathways in Atp7b-/- mice. Dynamic changes in FXR activity support our novel finding of altered bile acid metabolism in Atp7b-/- mice and WD patients.
Source: Hepatology Communications
Institutions: Baylor College of Medicine, Children's Nutrition Research Center at Baylor College of Medicine, Texas Children's Hospital, The University of Texas MD Anderson Cancer Center, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Yale University, Dan L Duncan Comprehensive Cancer Center, University of California, Berkeley
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,700
OpenAlex ID: W4410639409