Liver receptor homolog-1 (NR5a2) regulates CD95/Fas ligand transcription and associated T-cell effector functions

Cell Death Dis. 2017 Apr 13;8(4):e2745. doi: 10.1038/cddis.2017.173.

Abstract

CD95/Fas ligand (FasL) is a cell death-promoting member of the tumor necrosis factor family with important functions in the regulation of T-cell homeostasis and cytotoxicity. In T cells, FasL expression is tightly regulated on a transcriptional level involving a complex set of different transcription factors. The orphan nuclear receptor liver receptor homolog-1 (LRH-1/NR5a2) is involved in the regulation of development, lipid metabolism and proliferation and is predominantly expressed in epithelial tissues. However, its expression in T lymphocytes has never been reported so far. Based on in silico analysis, we identified potential LRH-1 binding sites within the FASLG promoter. Here, we report that LRH-1 is expressed in primary and secondary lymphatic tissues, as well as in CD4+ and CD8+ T cells. LRH-1 directly binds to its binding sites in the FASLG promoter, and thereby drives FASLG promoter activity. Mutations in the LRH-1 binding sites reduce FASLG promoter activity. Pharmacological inhibition of LRH-1 decreases activation-induced FasL mRNA expression, as well as FasL-mediated activation-induced T-cell apoptosis and T-cell cytotoxicity. In a mouse model of Concanavalin A-induced and FasL-mediated hepatitis pharmacological inhibition of LRH-1 resulted in decreased hepatic FasL expression and a significant reduction of liver damage. In summary, these data show for the first time LRH-1 expression in T cells, its role in FASLG transcription and the potential of pharmacological inhibition of LRH-1 in the treatment of FasL-mediated immunopathologies.

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / metabolism*
  • CD4-Positive T-Lymphocytes / pathology
  • CD8-Positive T-Lymphocytes / metabolism*
  • CD8-Positive T-Lymphocytes / pathology
  • Chemical and Drug Induced Liver Injury / genetics
  • Chemical and Drug Induced Liver Injury / metabolism
  • Chemical and Drug Induced Liver Injury / pathology
  • Concanavalin A / adverse effects
  • Concanavalin A / pharmacology
  • Disease Models, Animal
  • Fas Ligand Protein / biosynthesis*
  • Fas Ligand Protein / genetics
  • Gene Expression Regulation*
  • Liver / metabolism
  • Liver / pathology
  • Mice
  • Mice, Mutant Strains
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Response Elements*
  • Transcription, Genetic*

Substances

  • Fas Ligand Protein
  • Fasl protein, mouse
  • Nr5a2 protein, mouse
  • Receptors, Cytoplasmic and Nuclear
  • Concanavalin A