Odontoblast TRP channels and thermo/mechanical transmission.
Odontoblasts function as mechanosensory receptors because of the expression of mechanosensitive channels in these cells. However, it is unclear if odontoblasts direct the signal transmission evoked by heat/cold or osmotic changes. This study investigated the effects of heat/cold or osmotic changes on calcium signaling and the functional expression of the thermo/mechanosensitive transient receptor potential (TRP) channels in primary cultured mouse odontoblastic cells, with the use of RT-PCR, fluorometric calcium imaging, and electrophysiology. TRPV1, TRPV2, TRPV3, TRPV4, and TRPM3 mRNA was expressed, but TRPM8 and TRPA1 mRNA was not. The receptor-specific stimulation of TRPV1-3 (heat-sensing receptors) and TRPV4/ TRPM3 (mechanic receptors) caused increases in the intracellular calcium concentration. Moreover, the channel activities of TRPV1-4 and TRPM3 were confirmed by a whole-cell patch-clamp technique. These results suggest that primary cultured mouse odontoblasts express heat/mechanosensitive TRP channels and play a role in the underlying mechanisms of thermo/mechanosensitive sensory transmission.
Son
A R
AR
Department of Oral Biology, Brain Korea 21 Project, Yonsei University College of Dentistry, 134 Sinchon-dong Seodaemon-gu, Seoul, 120-752, Korea.
Yang
Y M
YM
Hong
J H
JH
Lee
S I
SI
Shibukawa
Y
Y
Shin
D M
DM
D000818:Animals; D000831:Animals, Newborn; D017089:Ankyrin Repeat; D015220:Calcium Channels / Q000032:analysis; D020013:Calcium Signaling / Q000502:physiology; D002478:Cells, Cultured; D003080:Cold Temperature; D003782:Dental Pulp / Q000166:cytology; D006358:Hot Temperature; D008465:Mechanoreceptors / Q000502:physiology; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D051379:Mice; D008813:Mice, Inbred ICR; D009804:Odontoblasts / Q000502:physiology*; D009995:Osmosis; D015398:Signal Transduction / Q000502:physiology*; D000074025:TRPA1 Cation Channel; D050053:TRPM Cation Channels / Q000032:analysis; D050916:TRPV Cation Channels / Q000032:analysis; D013697:Thermosensing / Q000502:physiology*; D050051:Transient Receptor Potential Channels / Q000032:analysis / Q000502:physiology*
D015220:Calcium Channels; D000074025:TRPA1 Cation Channel; D050053:TRPM Cation Channels; C533868:TRPM3 protein, mouse; C492297:TRPM8 protein, mouse; D050916:TRPV Cation Channels; C493921:TRPV1 protein, mouse; D050051:Transient Receptor Potential Channels; C475685:Trpa1 protein, mouse; C485717:Trpv2 protein, mouse; C486760:Trpv3 protein, mouse; C486576:Trpv4 protein, mouse