Tricellulin is regulated via interleukin-13-receptor α2, affects macromolecule uptake, and is decreased in ulcerative colitis

Mucosal Immunol. 2018 Mar;11(2):345-356. doi: 10.1038/mi.2017.52. Epub 2017 Jun 14.

Abstract

In the two inflammatory bowel diseases, ulcerative colitis (UC) and Crohn's disease (CD), altered expression of tight junction (TJ) proteins leads to an impaired epithelial barrier including increased uptake of luminal antigens supporting the inflammation. Here, we focused on regulation of tricellulin (Tric), a protein of the tricellular TJ essential for the barrier against macromolecules, and hypothesized a role in paracellular antigen uptake. We report that Tric is downregulated in UC, but not in CD, and that its reduction increases the passage of macromolecules. Using a novel visualization method, passage sites were identified at TJ regions usually sealed by Tric. We show that interleukin-13 (IL-13), beyond its known effect on claudin-2, downregulates Tric expression. These two effects of IL-13 are regulated by different signaling pathways: The IL-13 receptor α1 upregulates claudin-2, whereas IL-13 receptor α2 downregulates Tric. We suggest to target the α2 receptor in future developments of therapeutical IL-13-based biologicals.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antigens / immunology
  • Antigens / metabolism
  • Claudin-2 / metabolism
  • Colitis, Ulcerative / immunology*
  • Crohn Disease / immunology
  • Down-Regulation
  • Female
  • HT29 Cells
  • Humans
  • Inflammation / immunology*
  • Interleukin-13 / metabolism
  • Interleukin-13 Receptor alpha1 Subunit / metabolism
  • Interleukin-13 Receptor alpha2 Subunit / metabolism*
  • Intestinal Mucosa / physiology*
  • MARVEL Domain Containing 2 Protein / metabolism*
  • Macromolecular Substances / immunology
  • Macromolecular Substances / metabolism
  • Male
  • Middle Aged
  • Molecular Targeted Therapy
  • Signal Transduction
  • Tight Junctions / metabolism*
  • Young Adult

Substances

  • Antigens
  • Claudin-2
  • IL13RA1 protein, human
  • Interleukin-13
  • Interleukin-13 Receptor alpha1 Subunit
  • Interleukin-13 Receptor alpha2 Subunit
  • MARVEL Domain Containing 2 Protein
  • Macromolecular Substances