title: Transient receptor potential channels in sensory neurons are targets of the antimycotic agent clotrimazole.
abstract: Clotrimazole (CLT) is a widely used drug for the topical treatment of yeast infections of skin, vagina, and mouth. Common side effects of topical CLT application include irritation and burning pain of the skin and mucous membranes. Here, we provide evidence that transient receptor potential (TRP) channels in primary sensory neurons underlie these unwanted effects of CLT. We found that clinically relevant CLT concentrations activate heterologously expressed TRPV1 and TRPA1, two TRP channels that act as receptors of irritant chemical and/or thermal stimuli in nociceptive neurons. In line herewith, CLT stimulated a subset of capsaicin-sensitive and mustard oil-sensitive trigeminal neurons, and evoked nocifensive behavior and thermal hypersensitivity with intraplantar injection in mice. Notably, CLT-induced pain behavior was suppressed by the TRPV1-antagonist BCTC [(N-(-4-tertiarybutylphenyl)-4-(3-cholorpyridin-2-yl)tetrahydropyrazine-1(2H)-carboxamide)] and absent in TRPV1-deficient mice. In addition, CLT inhibited the cold and menthol receptor TRPM8, and blocked menthol-induced responses in capsaicin- and mustard oil-insensitive trigeminal neurons. The concentration for 50% inhibition (IC50) of inward TRPM8 current was approximately 200 nM, making CLT the most potent known TRPM8 antagonist and a useful tool to discriminate between TRPM8- and TRPA1-mediated responses. Together, our results identify TRP channels in sensory neurons as molecular targets of CLT, and offer means to develop novel CLT preparations with fewer unwanted sensory side effects.
authors.affiliation: Laboratory of Ion Channel Research, Division of Physiology, Department of Molecular Cell Biology, Campus Gasthuisberg O&N1, KU Leuven, B-3000 Leuven, Belgium.
authors.forename: Victor
authors.initials: V
authors.lastname: Meseguer
authors.forename: Yuji
authors.initials: Y
authors.lastname: Karashima
authors.forename: Karel
authors.initials: K
authors.lastname: Talavera
authors.forename: Dieter
authors.initials: D
authors.lastname: D'Hoedt
authors.forename: Tansy
authors.initials: T
authors.lastname: Donovan-Rodríguez
authors.forename: Felix
authors.initials: F
authors.lastname: Viana
authors.forename: Bernd
authors.initials: B
authors.lastname: Nilius
authors.forename: Thomas
authors.initials: T
authors.lastname: Voets
mesh_terms: D000818:Animals; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003022:Clotrimazole / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D051379:Mice; D018345:Mice, Knockout; D009475:Neurons, Afferent / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques / Q000379:methods; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D000074025:TRPA1 Cation Channel; D050053:TRPM Cation Channels / Q000235:genetics / Q000378:metabolism; D050916:TRPV Cation Channels / Q000235:genetics / Q000502:physiology*; D013997:Time Factors; D014162:Transfection / Q000379:methods; D050051:Transient Receptor Potential Channels / Q000172:deficiency / Q000502:physiology*; D012668:Trigeminal Ganglion / Q000166:cytology
chemical_list: D000891:Anti-Infective Agents, Local; D000074025:TRPA1 Cation Channel; D050053:TRPM Cation Channels; C425966:TRPM8 protein, human; D050916:TRPV Cation Channels; D050051:Transient Receptor Potential Channels; C475685:Trpa1 protein, mouse; D003022:Clotrimazole; D002118:Calcium