Involvement of VNUT-exocytosis in transient receptor potential vanilloid 4-dependent ATP release from gastrointestinal epithelium

PLoS One. 2018 Oct 26;13(10):e0206276. doi: 10.1371/journal.pone.0206276. eCollection 2018.

Abstract

Adenosine triphosphate (ATP) modulates mechanosensitive vagal afferent nerves in the gastrointestinal tract. ATP is stored in secretory vesicles via the ATP transporter VNUT. Recently, the bisphosphate clodronate was reported to inhibit VNUT and was suggested to be a safe potent therapeutic option for chronic pain. Transient receptor potential vanilloid 4 (TRPV4) is activated by mechanical stimuli and some epoxyeicosatrienoic acids and becomes sensitized under inflammatory conditions. We have previously reported that TRPV4 and VNUT are expressed in mouse esophageal keratinocytes and that TRPV4 activation induces ATP release in gastric epithelial cells. Here we show the expression of TRPV4 and VNUT in normal human gastrointestinal cell derived cell lines (GES-1 and CCD 841) and in tissues from normal and VNUT-KO mice. TRPV4 agonists (GSK101 or 8,9-EET) induced an increase in cytosolic Ca2+ and/or current responses in mouse primary colonic epithelial cells and CCD 841 cells, but not in cells isolated from TRPV4-KO mice. TRPV4 agonists (GSK101 or 5.6-EET) also induced ATP release in GES-1 and CCD 841 cells, which could be blocked by the VNUT inhibitor, clodronate. Thus, VNUT inhibition with clodronate could represent a novel therapeutic option for visceral pain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Animals
  • Calcium / metabolism
  • Cell Line
  • Epithelium / metabolism
  • Exocytosis*
  • Gastrointestinal Tract / metabolism*
  • Gene Expression Regulation
  • Humans
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Nucleotide Transport Proteins / metabolism*
  • TRPV Cation Channels / metabolism*

Substances

  • Nucleotide Transport Proteins
  • Slc17a9 protein, human
  • TRPV Cation Channels
  • TRPV4 protein, human
  • Adenosine Triphosphate
  • Calcium

Grants and funding

This work was supported by JSPS KAKENHI Grant Number JP26870214 to H.M.