The P2Y6 receptor mediates Clostridium difficile toxin-induced CXCL8/IL-8 production and intestinal epithelial barrier dysfunction

PLoS One. 2013 Nov 22;8(11):e81491. doi: 10.1371/journal.pone.0081491. eCollection 2013.

Abstract

C. difficile is a Gram-positive spore-forming anaerobic bacterium that is the leading cause of nosocomial diarrhea in the developed world. The pathogenesis of C. difficile infections (CDI) is driven by toxin A (TcdA) and toxin B (TcdB), secreted factors that trigger the release of inflammatory mediators and contribute to disruption of the intestinal epithelial barrier. Neutrophils play a key role in the inflammatory response and the induction of pseudomembranous colitis in CDI. TcdA and TcdB alter cytoskeletal signaling and trigger the release of CXCL8/IL-8, a potent neutrophil chemoattractant, from intestinal epithelial cells; however, little is known about the surface receptor(s) that mediate these events. In the current study, we sought to assess whether toxin-induced CXCL8/IL-8 release and barrier dysfunction are driven by the activation of the P2Y6 receptor following the release of UDP, a danger signal, from intoxicated Caco-2 cells. Caco-2 cells express a functional P2Y6 receptor and release measurable amounts of UDP upon exposure to TcdA/B. Toxin-induced CXCL8/IL-8 production and release were attenuated in the presence of a selective P2Y6 inhibitor (MRS2578). This was associated with inhibition of TcdA/B-induced activation of NFκB. Blockade of the P2Y6 receptor also attenuated toxin-induced barrier dysfunction in polarized Caco-2 cells. Lastly, pretreating mice with the P2Y6 receptor antagonists (MSR2578) attenuated TcdA/B-induced inflammation and intestinal permeability in an intrarectal toxin exposure model. Taken together these data outline a novel role for the P2Y6 receptor in the induction of CXCL8/IL-8 production and barrier dysfunction in response to C. difficile toxin exposure and may provide a new therapeutic target for the treatment of CDI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apyrase / metabolism
  • Caco-2 Cells
  • Clostridioides difficile / metabolism*
  • Disease Models, Animal
  • Enterocolitis, Pseudomembranous / genetics
  • Enterocolitis, Pseudomembranous / metabolism*
  • Enterocolitis, Pseudomembranous / physiopathology*
  • Enterotoxins / metabolism*
  • Humans
  • Inflammation / genetics
  • Inflammation / metabolism
  • Interleukin-8 / biosynthesis*
  • Intestinal Mucosa / metabolism*
  • Intestinal Mucosa / microbiology
  • Intestinal Mucosa / physiopathology*
  • Male
  • Mice
  • NF-kappa B / metabolism
  • Purinergic P2 Receptor Antagonists / pharmacology
  • Receptors, Purinergic P2 / metabolism*
  • Signal Transduction

Substances

  • Enterotoxins
  • Interleukin-8
  • NF-kappa B
  • Purinergic P2 Receptor Antagonists
  • Receptors, Purinergic P2
  • purinoceptor P2Y6
  • Apyrase