System analysis of cross-talk between nuclear receptors reveals an opposite regulation of the cell cycle by LXR and FXR in human HepaRG liver cells

PLoS One. 2019 Aug 22;14(8):e0220894. doi: 10.1371/journal.pone.0220894. eCollection 2019.

Abstract

Transcriptional regulations exert a critical control of metabolic homeostasis. In particular, the nuclear receptors (NRs) are involved in regulating numerous pathways of the intermediate metabolism. The purpose of the present study was to explore in liver cells the interconnectedness between three of them, LXR, FXR, and PPARα, all three known to act on lipid and glucose metabolism, and also on inflammation. The human cell line HepaRG was selected for its best proximity to human primary hepatocytes. Global gene expression of differentiated HepaRG cells was assessed after 4 hours and 24 hours of exposure to GW3965 (LXR agonist), GW7647 (PPARα agonist), and GW4064 and CDCA (FXR synthetic and natural agonist, respectively). Our work revealed that, contrary to our expectations, NR specificity is largely present at the level of target genes, with a smaller than expected overlap of the set of genes targeted by the different NRs. It also highlighted the much broader activity of the synthetic FXR ligand compared to CDCA. More importantly, our results revealed that activation of FXR has a pro-proliferative effect and decreases the number of tetraploid (or binucleated) hepatocytes, while LXR inhibits the cell cycle progression, inducing hepatocyte differentiation and an increase in tetraploidism. Conclusion: these results highlight the importance of analyzing the different NR activities in a context allowing a direct confrontation of each receptor outcome, and reveals the opposite role of FXR and LXR in hepatocyte cells division and maturation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzoates
  • Benzylamines
  • Butyrates
  • Cell Cycle / genetics
  • Cell Cycle / physiology
  • Cell Cycle Proteins / physiology
  • Cell Differentiation / physiology
  • Cell Line
  • Cell Proliferation / physiology
  • Gene Expression / genetics
  • Gene Expression Regulation / genetics
  • Hepatocytes / metabolism
  • Humans
  • Isoxazoles
  • Liver / pathology
  • Liver X Receptors / immunology
  • Liver X Receptors / metabolism*
  • Orphan Nuclear Receptors / metabolism
  • PPAR alpha / immunology
  • PPAR alpha / metabolism
  • Phenylurea Compounds
  • Promoter Regions, Genetic / genetics
  • Receptor Cross-Talk / physiology*
  • Receptors, Cytoplasmic and Nuclear / immunology
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Systems Analysis

Substances

  • Benzoates
  • Benzylamines
  • Butyrates
  • Cell Cycle Proteins
  • GW 3965
  • GW 7647
  • Isoxazoles
  • Liver X Receptors
  • Orphan Nuclear Receptors
  • PPAR alpha
  • Phenylurea Compounds
  • Receptors, Cytoplasmic and Nuclear
  • farnesoid X-activated receptor
  • GW 4064

Grants and funding

This study was supported by the Etat de vaud, FNRS (grant 31003A_135583/1 and 310030_156771/1; BD) Novartis (Grant to CC), and FP7 NR-NET (606806; BD). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.