Hepatic FXR/SHP axis modulates systemic glucose and fatty acid homeostasis in aged mice

• Published in: Hepatology (Baltimore, Md.) Vol. 66; no. 2; pp. 498 - 509
• Main Authors: Kim, Kang Ho, Choi, Sungwoo, Zhou, Ying, Kim, Eun Young, Lee, Jae Man, Saha, Pradip K., Anakk, Sayeepriyadarshini, Moore, David D.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.08.2017
• Subjects: Adipose tissue; Adipose tissue (brown); Aging - genetics; Analysis of Variance; Animals; Autophagy - genetics; Bile; Body weight gain; Cells, Cultured; Cholestasis; Disease Models, Animal; Energy balance; Fatty acids; Fatty Acids - metabolism; Gene Deletion; Gene expression; Gene Expression Regulation; Glucose - metabolism; Glucose tolerance; Hepatocytes - cytology; Hepatocytes - metabolism; Hepatology; Homeostasis; Homeostasis - genetics; Insulin; Lipid Metabolism - genetics; Liver; Liver - metabolism; Male; Metabolism; Mice; Mice, Inbred C57BL; Mice, Knockout; Nuclear receptors; Phagocytosis; Protein Tyrosine Phosphatase, Non-Receptor Type 6 - genetics; Random Allocation; Receptors, Cytoplasmic and Nuclear - genetics; Rodents
• ISSN: 0270-9139; 1527-3350
• DOI: 10.1002/hep.29199

The nuclear receptors farnesoid X receptor (FXR; NR1H4) and small heterodimer partner (SHP; NR0B2) play crucial roles in bile acid homeostasis. Global double knockout of FXR and SHP signaling (DKO) causes severe cholestasis and liver injury at early ages. Here, we report an unexpected beneficial impact on glucose and fatty acid metabolism in aged DKO mice, which show suppressed body weight gain and adiposity when maintained on normal chow. This phenotype was not observed in single Fxr or Shp knockouts. Liver‐specific Fxr/Shp double knockout mice fully phenocopied the DKO mice, with lower hepatic triglyceride accumulation, improved glucose/insulin tolerance, and accelerated fatty acid use. In both DKO and liver‐specific Fxr/Shp double knockout livers, these metabolic phenotypes were associated with altered expression of fatty acid metabolism and autophagy‐machinery genes. Loss of the hepatic FXR/SHP axis reprogrammed white and brown adipose tissue gene expression to boost fatty acid usage. Conclusion: Combined deletion of the hepatic FXR/SHP axis improves glucose/fatty acid homeostasis in aged mice, reversing the aging phenotype of body weight gain, increased adiposity, and glucose/insulin tolerance, suggesting a central role of this axis in whole‐body energy homeostasis. (Hepatology 2017;66:498–509).