Upregulation of KSRP by miR-27b provides IFN-γ-induced post-transcriptional regulation of CX3CL1 in liver epithelial cells

Sci Rep. 2015 Dec 3:5:17590. doi: 10.1038/srep17590.

Abstract

Aberrant cellular responses to pro-inflammatory cytokines, such as IFN-γ, are pathogenic features in many chronic inflammatory diseases. A variety of feedback regulatory pathways have evolved to prevent an inappropriate cellular reaction to these pro-inflammatory cytokines. CX3CL1 is a unique chemokine and plays an important role in chronic liver diseases. We report here that IFN-γ stimulation induces a transient CX3CL1 production in liver epithelial cells (i.e., hepatocytes and biliary epithelial cells). This transient CX3CL1 production is accompanied with a destabilization of CX3CL1 mRNA associated with the induction of the KH-type splicing regulatory protein (KSRP). IFN-γ treatment of liver epithelial cells decreases expression level of miR-27b, a miRNA that targets the 3' untranslated region of KSRP mRNA resulting in translational suppression. Induction of KSRP following IFN-γ stimulation depends on the downregulation of miR-27b. Functional manipulation of KSRP or miR-27b caused reciprocal alterations in CX3CL1 mRNA stability in liver epithelial cells. Moreover, transfection of miR-27b precursor influences CX3CL1-associated chemotaxis effects of biliary epithelial cells to Jurkat T cells. These findings suggest that miR-27b-mediated post-transcriptional suppression controls the expression of KSRP in liver epithelial cells, and upregulation of KSRP destabilizes CX3CL1 mRNA, providing fine-tuning of cellular inflammatory reactions in response to IFN-γ stimulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chemokine CX3CL1 / genetics*
  • Chemokine CX3CL1 / metabolism
  • Chemotaxis / genetics
  • Epithelial Cells / drug effects
  • Gene Expression Regulation / drug effects
  • Humans
  • Interferon-gamma / metabolism*
  • Interferon-gamma / pharmacology
  • Liver / cytology*
  • Liver / drug effects
  • Male
  • Mice, Inbred C57BL
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • RNA Stability / drug effects
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Response Elements / genetics
  • Trans-Activators / genetics
  • Trans-Activators / metabolism*
  • Up-Regulation / drug effects

Substances

  • CX3CL1 protein, human
  • Chemokine CX3CL1
  • KHSRP protein, human
  • MIRN27 microRNA, human
  • MicroRNAs
  • RNA-Binding Proteins
  • Trans-Activators
  • Interferon-gamma