title: Isopentenyl pyrophosphate is a novel antinociceptive substance that inhibits TRPV3 and TRPA1 ion channels.
abstract: Transient receptor potential ion channels (TRPs) expressed in the periphery sense and electrically transduce noxious stimuli to transmit the signals to the brain. Many natural and synthetic ligands for the sensory TRPs have been found, but little is known about endogenous inhibitors of these TRP channels. Recently, we reported that farnesyl pyrophosphate, an endogenous substance produced in the mevalonate pathway, is a specific activator for TRPV3. Here, we show that isopentenyl pyrophosphate (IPP), an upstream metabolite in the same pathway, is a dual inhibitor for TRPA1 and TRPV3. By using Ca(2+) imaging and voltage clamp experiments with human embryo kidney cell heterologous expression system, cultured sensory neurons, and epidermal keratinocytes, we demonstrate that micromolar IPP suppressed responses to specific agonists of TRPA1 and TRPV3. Consistently, peripheral IPP administration attenuated TRPA1 and TRPV3 agonist-specific acute pain behaviors. Furthermore, local IPP pretreatment significantly reversed mechanical and thermal hypersensitivity of inflamed animals. Taken together, the present study suggests that IPP is a novel endogenous TRPA1 and TRPV3 inhibitor that causes local antinociception. Our results may provide useful chemical information to elucidate TRP physiology in peripheral pain sensation.
authors.affiliation: Korea University Graduate School of Medicine, Seoul 136-705, Republic of Korea Sensory Research Center, CRI, Seoul National University College of Pharmacy, Seoul 151-742, Republic of Korea.
authors.forename: Sangsu
authors.initials: S
authors.lastname: Bang
authors.forename: Sungjae
authors.initials: S
authors.lastname: Yoo
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Yang
authors.forename: Hawon
authors.initials: H
authors.lastname: Cho
authors.forename: Sun Wook
authors.initials: SW
authors.lastname: Hwang
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005620:Freund's Adjuvant / Q000009:adverse effects; D005727:Ganglia, Spinal / Q000166:cytology; D005786:Gene Expression Regulation / Q000187:drug effects; D045782:Hemiterpenes / Q000494:pharmacology*; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000150:complications; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008813:Mice, Inbred ICR; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D010146:Pain / Q000188:drug therapy / Q000209:etiology; D018408:Patch-Clamp Techniques / Q000379:methods; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D011984:Sensory Receptor Cells / Q000187:drug effects*; D000074025:TRPA1 Cation Channel; D050916:TRPV Cation Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection / Q000379:methods; D050051:Transient Receptor Potential Channels / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D000700:Analgesics; D015220:Calcium Channels; D045782:Hemiterpenes; D009419:Nerve Tissue Proteins; D009943:Organophosphorus Compounds; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D000074025:TRPA1 Cation Channel; C473350:TRPA1 protein, human; D050916:TRPV Cation Channels; C459445:TRPV3 protein, human; D050051:Transient Receptor Potential Channels; C004809:isopentenyl pyrophosphate; D000171:Acrolein; D005620:Freund's Adjuvant; C012843:cinnamaldehyde; D002118:Calcium