Proteinase-activated receptor-2 mediates itch: a novel pathway for pruritus in human skin

J Neurosci. 2003 Jul 16;23(15):6176-80. doi: 10.1523/JNEUROSCI.23-15-06176.2003.

Abstract

We examined whether neuronal proteinase-activated receptor-2 (PAR-2) may be involved in pruritus of human skin. The endogenous PAR-2 agonist tryptase was increased up to fourfold in atopic dermatitis (AD) patients. PAR-2 was markedly enhanced on primary afferent nerve fibers in skin biopsies of AD patients. Intracutaneous injection of endogenous PAR-2 agonists provoked enhanced and prolonged itch when applied intralesionally. Moreover, itch upon mast cell degranulation was abolished by local antihistamines in controls but prevailed in AD patients. Thus, we identified enhanced PAR-2 signaling as a new link between inflammatory and sensory phenomena in AD patients. PAR-2 therefore represents a promising therapeutic target for the treatment of cutaneous neurogenic inflammation and pruritus.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analgesics, Opioid / pharmacology
  • Biopsy
  • Cell Degranulation / drug effects
  • Codeine / pharmacology
  • Dermatitis, Atopic / complications
  • Dermatitis, Atopic / pathology
  • Dermatitis, Atopic / physiopathology*
  • Dose-Response Relationship, Drug
  • Female
  • Histamine / metabolism
  • Histamine H1 Antagonists / pharmacology
  • Humans
  • Immunohistochemistry
  • Injections, Intralesional
  • Injections, Subcutaneous
  • Male
  • Mast Cells / drug effects
  • Mast Cells / metabolism
  • Mast Cells / pathology
  • Microdialysis
  • Neurons, Afferent / metabolism
  • Oligopeptides / pharmacology
  • Pruritus / etiology
  • Pruritus / physiopathology*
  • Receptor, PAR-2
  • Receptors, Thrombin / agonists
  • Receptors, Thrombin / metabolism*
  • Reference Values
  • Serine Endopeptidases / metabolism
  • Signal Transduction / physiology*
  • Skin / metabolism
  • Skin / pathology
  • Skin / physiopathology*
  • Tryptases

Substances

  • Analgesics, Opioid
  • Histamine H1 Antagonists
  • Oligopeptides
  • Receptor, PAR-2
  • Receptors, Thrombin
  • seryl-leucyl-isoleucyl--glycyl-lysyl-valine
  • Histamine
  • Serine Endopeptidases
  • Tryptases
  • Codeine