The temperature-sensitive ion channel TRPV2 is endogenously expressed and functional in the primary sensory cell line F-11.
In sensory neurons heat is transduced by a subfamily of TRP channels sharing sequence homology with the capsaicin-sensitive vanilloid receptor subtype 1 (TRPV1), but differing in their thermal response thresholds. To identify a neuronal cell line endogenously expressing noxious heat-transducing ion channels, we examined F-11 cells, a hybridoma derived from rat dorsal root ganglia and mouse neuroblastoma. Using RT-PCR, transcripts homologous to TRPV2 and TRPV4, but not to TRPV1 or TRPV3, were found. We isolated a full-length cDNA of 2.4 kb coding for a 757-amino acid protein corresponding to mouse TRPV2, which was further characterized by immunocytochemistry and electrophysiology. Using the whole-cell patch-clamp technique, we observed a heat-evoked increase in outward and inward currents with a threshold of 51.6 +/- 0.2 degrees C. The current-voltage relationship stimulated by a temperature of 52 degrees C was characterized by an outward rectification with a reversal potential close to -10 mV. Heat-evoked currents could be inhibited by ruthenium red. There was no activation by stimulation with capsaicin or 2-aminoethoxydiphenyl borate. Our results indicate that F-11 cells express functional noxious heat-sensitive TRPV2 channels. Thus, we propose that F-11 cells represent a valuable in vitro model to characterize the properties of TRPV2 in a native neuronal environment.
Bender
Florian L P
FL
Molecular Neuroscience, Institute of Anatomy and Cell Biology, Philipps University Marburg, Marburg, Germany.
Mederos Y Schnitzler
Michael
M
Li
Yanzhang
Y
Ji
Ailing
A
Weihe
Eberhard
E
Gudermann
Thomas
T
Schäfer
Martin K-H
MK
D000818:Animals; D002460:Cell Line; D005727:Ganglia, Spinal / Q000378:metabolism; D006801:Humans; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D011955:Receptors, Drug / Q000235:genetics / Q000378:metabolism*; D050916:TRPV Cation Channels; D013696:Temperature
D007473:Ion Channels; D020033:Protein Isoforms; D012333:RNA, Messenger; D011955:Receptors, Drug; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat; C476722:Trpv2 protein, rat