Effect of lipid raft disruption on TRPV1 receptor activation of trigeminal sensory neurons and transfected cell line.
The transient receptor potential vanilloid 1 (TRPV1) is a noxious heat-sensitive, chemonociceptive cation channel which is expressed in primary sensory neurons of polymodal nociceptors. The present study is devoted to analyse the role of lipid raft constituents in calcium influx evoked by various TRPV1 agonists on sensory neurons and on rTRPV1-transfected CHO cell line. Depletion of cholesterol by methyl beta-cyclodextrin (MCD, 1-10mM) diminished the percent of the calcium uptake response of cultured trigeminal neurons to capsaicin (100nM) or resiniferatoxin (RTX, 3nM). In contrast, in TRPV1-transfected cells the inhibition was observed only when capsaicin or N-oleoyldopamine (OLDA, 10microM) was applied, but not when RTX, anandamide (AEA, 10microM) or pH 5.5 was used for gating. The magnitude of Ca(2+)-transients evoked by capsaicin (330nM) was also inhibited in both cell types. Treatment of rTRPV1-expressing cells with sphinomyelinase inhibited the capsaicin-evoked (45)Ca-uptake leaving the RTX-induced response unchanged. On the other hand, in trigeminal neurons the effect of both compounds was inhibited by sphingomyelinase treatment. Inhibition of ganglioside biosynthesis by d-threo-1-Phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP, 10-20microM) or myriocyn (5-50nM) diminished similarly capsaicin- or RTX-evoked calcium uptake in both cultured trigeminal neurons and rTRPV1-expressing cells. The present study revealed that depletion of different constituents of lipid raft inhibited gating the TRPV1 cation channel by various vanilloid and non-vanilloid agents. Evidence for a supporting role of cholesterol, sphingomyelin and gangliosides were obtained both in native and TRPV1-transfected cells. Differential modulation of responses to capsaicin and RTX was often observed.
Szoke
Eva
E
Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Pécs, Pécs, Hungary. eva.szoke@aok.pte.hu
Börzsei
Rita
R
Tóth
Dániel Márton
DM
Lengl
Orsolya
O
Helyes
Zsuzsanna
Z
Sándor
Zoltán
Z
Szolcsányi
János
J
D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D002784:Cholesterol / Q000172:deficiency; D003001:Cloning, Molecular; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D005732:Gangliosides / Q000096:biosynthesis / Q000172:deficiency; D005786:Gene Expression Regulation / Q000187:drug effects; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D021962:Membrane Microdomains / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011984:Sensory Receptor Cells / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D013108:Sphingomyelin Phosphodiesterase / Q000494:pharmacology; D013109:Sphingomyelins / Q000172:deficiency; D050916:TRPV Cation Channels / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D012668:Trigeminal Ganglion / Q000166:cytology*; D047392:beta-Cyclodextrins / Q000494:pharmacology
D005732:Gangliosides; D013109:Sphingomyelins; D050916:TRPV Cation Channels; C494484:TRPV1 receptor; C493922:Trpv1 protein, rat; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D002784:Cholesterol; D013108:Sphingomyelin Phosphodiesterase