title: Resolvin D1 attenuates activation of sensory transient receptor potential channels leading to multiple anti-nociception.
abstract: OBJECTIVE
  Temperature-sensitive transient receptor potential ion channels (thermoTRPs) expressed in primary sensory neurons and skin keratinocytes play a crucial role as peripheral pain detectors. Many natural and synthetic ligands have been found to act on thermoTRPs, but little is known about endogenous compounds that inhibit these TRPs. Here, we asked whether resolvin D1 (RvD1), a naturally occurring anti-inflammatory and pro-resolving lipid molecule is able to affect the TRP channel activation.
  
  
  METHODS
  We examined the effect of RvD1 on the six thermoTRPs using Ca(2+) imaging and whole cell electrophysiology experiments using the HEK cell heterologous expression system, cultured sensory neurons and HaCaT keratinocytes. We also checked changes in agonist-specific acute licking/flicking or flinching behaviours and TRP-related mechanical and thermal pain behaviours using Hargreaves, Randall-Selitto and von Frey assay systems with or without inflammation.
  
  
  RESULTS
  RvD1 inhibited the activities of TRPA1, TRPV3 and TRPV4 at nanomolar and micromolar levels. Consistent attenuations in agonist-specific acute pain behaviours by immediate peripheral administration with RvD1 were also observed. Furthermore, local pretreatment with RvD1 significantly reversed mechanical and thermal hypersensitivity in inflamed tissues.
  
  
  CONCLUSIONS
  RvD1 was a novel endogenous inhibitor for several sensory TRPs. The results of our behavioural studies suggest that RvD1 has an analgesic potential via these TRP-related mechanisms.
authors.affiliation: Korea University Graduate School of Medicine, Seoul, Korea.
authors.forename: S
authors.initials: S
authors.lastname: Bang
authors.forename: S
authors.initials: S
authors.lastname: Yoo
authors.forename: T J
authors.initials: TJ
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Cho
authors.forename: Y G
authors.initials: YG
authors.lastname: Kim
authors.forename: S W
authors.initials: SW
authors.lastname: Hwang
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004281:Docosahexaenoic Acids / Q000494:pharmacology / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D051379:Mice; D010147:Pain Measurement / Q000187:drug effects*; D018408:Patch-Clamp Techniques / Q000379:methods; D000074025:TRPA1 Cation Channel; D050916:TRPV Cation Channels / Q000037:antagonists & inhibitors / Q000502:physiology*; D050051:Transient Receptor Potential Channels / Q000037:antagonists & inhibitors / Q000502:physiology*
chemical_list: D000074025:TRPA1 Cation Channel; D050916:TRPV Cation Channels; D050051:Transient Receptor Potential Channels; C475685:Trpa1 protein, mouse; C518399:resolvin D1; D004281:Docosahexaenoic Acids