title: The distinct roles of two GPCRs, MrgprC11 and PAR2, in itch and hyperalgesia.
abstract: Itch has been defined as an unpleasant skin sensation that triggers the urge to scratch. Primary sensory dorsal root ganglia neurons detect itch stimuli through peripheral axons in the skin, playing an important role in generating itch. Itch is broadly categorized as histaminergic (sensitive to antihistamines) or nonhistaminergic. The peptide Ser-Leu-Ile-Gly-Arg-Leu (SLIGRL) is an itch-inducing agent widely used to study histamine-independent itch. Here, we show that Mrgprs (Mas-related G protein-coupled receptors), particularly MrgprC11, rather than PAR2 (protease-activated receptor 2) as previously thought, mediate this type of itch. A shorter peptide, SLIGR, which specifically activates PAR2 but not MrgprC11, induced thermal pain hypersensitivity in mice but not a scratch response. Therefore, although both Mrgpr and PAR2 are SLIGRL-responsive G protein-coupled receptors present in dorsal root ganglia, each plays a specific role in mediating itch and pain.
authors.affiliation: Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
authors.forename: Qin
authors.initials: Q
authors.lastname: Liu
authors.forename: Hao-Jui
authors.initials: HJ
authors.lastname: Weng
authors.forename: Kush N
authors.initials: KN
authors.lastname: Patel
authors.forename: Zongxiang
authors.initials: Z
authors.lastname: Tang
authors.forename: Haihua
authors.initials: H
authors.lastname: Bai
authors.forename: Martin
authors.initials: M
authors.lastname: Steinhoff
authors.forename: Xinzhong
authors.initials: X
authors.lastname: Dong
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000378:metabolism*; D006930:Hyperalgesia / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009842:Oligopeptides / Q000009:adverse effects / Q000494:pharmacology; D011537:Pruritus / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism*; D044464:Receptor, PAR-2 / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000819:agonists / Q000235:genetics / Q000378:metabolism*
chemical_list: D009842:Oligopeptides; D044464:Receptor, PAR-2; D043562:Receptors, G-Protein-Coupled; C470192:Mrgprx1 protein, mouse; C099570:seryl-leucyl-isoleucyl-glycyl-arginyl-leucine