20-hydroxyeicosatetraenoic acid (20-HETE) activates mouse TRPC6 channels expressed in HEK293 cells.
In the present study, we show that the eicosanoid compound, 20-hydroxyeicosatetraenoic acid (20-HETE), an important arachidonic acid metabolite, activates mouse TRPC6 in a stable, overexpressing HEK293 cell line, Hek-t6.11. Application of 20-HETE rapidly induced an inward, non-selective current in whole-cell recordings, which was inhibited by N-methyl-d-glucamine, 1.8 mm Ca2+, and 100 microM Gd3+ but remained unaffected by flufenamate and indomethacin. The current-voltage relationship obtained at low concentrations of 20-HETE (1-10 microM) demonstrated slight inward rectification, whereas the highest concentration of 20-HETE tested (30 microM) showed outward rectification, as shown previously for these channels using 100 microM 1-oleoyl-2-acetyl-sn-glycerol. Dose-response curves indicate that 20-HETE activated TRPC6 channels with an EC50 = 0.8 microM. Single channel analysis using inside-out patches revealed that 20-HETE increased open probability of mouse TRPC6 channels approximately 3-fold, and this was in a membrane-delimited fashion. Interestingly, 20-HETE did not provoke changes in intracellular Ca2+ concentrations. Thus, we have identified an arachidonic acid metabolite, 20-HETE, as a novel activator for a TRP family member, TRPC6.
Basora
Nuria
N
Department of Physiology and Biophysics, Faculty of Medicine, University of Sherbrooke, Québec J1H 5N4, Canada. Nuria.Basora@USherbrooke.ca
Boulay
Guylain
G
Bilodeau
Lyne
L
Rousseau
Eric
E
Payet
Marcel D
MD
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects* / Q000378:metabolism; D002460:Cell Line; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology*; D008297:Male; D008536:Meglumine / Q000494:pharmacology; D051379:Mice; D018408:Patch-Clamp Techniques; D011994:Recombinant Proteins / Q000378:metabolism; D050052:TRPC Cation Channels; D000074287:TRPC6 Cation Channel
D015220:Calcium Channels; D006893:Hydroxyeicosatetraenoic Acids; D011994:Recombinant Proteins; D050052:TRPC Cation Channels; D000074287:TRPC6 Cation Channel; C117032:TRPC6 protein, human; C492146:Trpc6 protein, mouse; D008536:Meglumine; C055987:20-hydroxy-5,8,11,14-eicosatetraenoic acid; D002118:Calcium