TRPV1 channels and the progesterone receptor Sig-1R interact to regulate pain

Proc Natl Acad Sci U S A. 2018 Feb 13;115(7):E1657-E1666. doi: 10.1073/pnas.1715972115. Epub 2018 Jan 29.

Abstract

The Transient Receptor Potential Vanilloid 1 (TRPV1) ion channel is expressed in nociceptors where, when activated by chemical or thermal stimuli, it functions as an important transducer of painful and itch-related stimuli. Although the interaction of TRPV1 with proteins that regulate its function has been previously explored, their modulation by chaperones has not been elucidated, as is the case for other mammalian TRP channels. Here we show that TRPV1 physically interacts with the Sigma 1 Receptor (Sig-1R), a chaperone that binds progesterone, an antagonist of Sig-1R and an important neurosteroid associated to the modulation of pain. Antagonism of Sig-1R by progesterone results in the down-regulation of TRPV1 expression in the plasma membrane of sensory neurons and, consequently, a decrease in capsaicin-induced nociceptive responses. This is observed both in males treated with a synthetic antagonist of Sig-1R and in pregnant females where progesterone levels are elevated. This constitutes a previously undescribed mechanism by which TRPV1-dependent nociception and pain can be regulated.

Keywords: TRPV1; chaperone; pain; progesterone; sigma 1 receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Capsaicin / metabolism
  • Cell Line
  • Cell Membrane / genetics
  • Cell Membrane / metabolism
  • Female
  • Humans
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Pain / genetics
  • Pain / metabolism*
  • Progesterone / metabolism
  • Protein Binding
  • Receptors, sigma / metabolism*
  • Sensory Receptor Cells / metabolism
  • TRPV Cation Channels / genetics
  • TRPV Cation Channels / metabolism*

Substances

  • Receptors, sigma
  • TRPV Cation Channels
  • TRPV1 protein, mouse
  • sigma-1 receptor
  • Progesterone
  • Capsaicin